43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Physics [16 ed.] 8194767733, 9788194767732


891 29 17MB

English Pages 656 Year 2020

Report DMCA / Copyright

DOWNLOAD PDF FILE

Table of contents :
Contents
1. Physical World, Units
and Measurements
2. Motion in a Straight
Line
3. Motion in a Plane
4. Laws of Motion
5. Work, Energy and Power
6. System of Particles and
Rotational Motion
7. Gravitation
8. Mechanical Properties
of Solids
9. Mechanical Properties
of Fluids
10. Thermal Properties
of Matter
11. Thermodynamics
12. Kinetic Theory
13. Oscillations
14. Waves
15. Electric Charges
and Fields
16. Electrostatic Potential
and Capacitance
17. Current Electricity
18. Moving Charges
and Magnetism
19. Magnetism and Matter
20. Electromagnetic
Induction
21. Alternating Current
22. Electromagnetic
Waves
23. Ray Optics and
Optical Instruments
24. Wave Optics
25. Dual Nature of
Radiation and Matter
26. Atoms
27. Nuclei
28. Semiconductor Electronics:
Materials, Devices and
Simple Circuits
29. Communication
Systems
Recommend Papers

43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Physics [16 ed.]
 8194767733, 9788194767732

  • Commentary
  • decrypted from 7CA865ACFA7FEDD47B7F90FD3D948EEA source file
  • 1 0 0
  • Like this paper and download? You can publish your own PDF file online for free in a few minutes! Sign Up
File loading please wait...
Citation preview

EBD_8341

EBD_8341

EBD_8341

EBD_8341

P-1

Physical World, Units and Measurements

1

Topic-1 : Unit of Physical Quantities 1 ҈

MCQs with One Correct Answer

  矄�泐ᨨ  鼀�� 和ᔼ盐 � �矄҈├�鼀 ᔼ

ᆠ�  盐 �矄�  犨 �ᆠ   盐 � ᨨ  �  �矄�ᆠ鼀   盐 �ᨨ 鼀矄矄�矄��  盐鼀�ᆠ盐ᨨ   矄�泐 ᨨ  鼀��矄 ᲼㝐� ҈ ҈黨 ᔼ㡰桌 㡰 



㡰

ᆠ㡰 

㡰 ҈

㡰 ҈

꾀鼀矄鼀ᆠ泐� �ᆠ盐 ᨨ �㜠 �矄犨�   矄�泐  �矄矄盐ᆠ ᨨ鼀� �ᆠ �   ᨨ � 㜠 �矄㡰  ᆠ�ᆠ �  쟼 泐 ᨨ  ᨨ � Ӹ㜠 �矄 �矄 �ᆠ泐 ᨨᨨ�ᨨ  ᨨ   矄 犨 矄    ᆠᨨ 矄  ᨨ ᨨᨨ�ᨨ �泐 矄和ᔼ盐 �

ᔴ㡰

㡰

ᆠ㡰 ᨨ盐⏌ 鼀㡰 7 

q  B

 F ᨨᆠ

GM e G盐 �矄 

꾀㡰 GMeMs , G 盐 �矄���ᨨ  ᆠᨨ 矄 

�

㡰 ᨨ 鼀㜠矄ᆠᨨ

ᔴᨨ盐鼀 ᔼ 꾀㡰 ᔴᆠ� ᆠ 㡰 ᔼ 盐ᆠ ᆠ ᔴ㡰 㝐� �ᆠᔼ 盐ᆠ�ᨨ

Me鼀矄矄ᨨ    Ms鼀矄矄ᨨ  和盐

ᔴᨨ盐鼀 ᔼᔼ

矄㡰  㡰 ᨨ㡰 ├�㡰҈

�㡰 ��㡰 ���㡰 �㡰 㡰

ᔴᨨ盐鼀 ᔼᔼ ᨨ 鼀㜠矄ᆠᨨ ᆠᨨ盐ᨨ鼀ᨨ盐҈ ᆠᨨ盐ᨨ鼀 ᨨ㡰҈

犨ᨨ  鼀㜠鼀㡰҈ ᨨ㜠矄ᆠᨨ  鼀㡰҈ ᲼҈黨黨㜠㝐├矄桌

10 Subjective Problems

㡰 ᨨ㡰 ᆠᨨ盐ᨨ鼀㡰 鼀㡰 ᲼䰘桌

㡰 鼀㡰 矄ᆠᨨ 㡰

Re �盐矄ᨨ  

Match the Following ᔴᨨ盐鼀 ᔼ

矄ᆠᨨ 㡰

Me鼀矄矄ᨨ   

㡰 

F

⼄㡰 ├�ᨨ�鼀㡰 鼀㡰

qᆠ � B鼀� �ᆠ �

᲼㝐� 졠 � 꾀��҈桌 As m m m 㡰 ᆠ㡰 㡰 As As m A SI盐 �ᨨ � 盐ᆠ ᆠ   泐ᆠ 犨� 矄 ᲼҈黨黨㜠㝐├矄桌 㡰 犨⏌鼀 㡰 ᨨ㜠矄ᆠ⏌鼀

RT  R盐 �矄 M �矄 ᆠᨨ 矄  T矄ᨨ盐鼀盐 M鼀ᨨ鼀矄矄



෌� 㝐⧤和盐 �矄 ᨨᆠ ᨨ   ᨨᨨ犨� �⼄盐 ��矄 꾀㡰 Ӹᨨ盐 �矄鼀ᨨ 盐盐矄

᲼҈黨桌

㡰 㝐� �ᆠᔼ 盐ᆠ�ᨨ

ᔴ㡰 ᨨ犨ᨨ  矄

WWW.JEEBOOKS.IN

EBD_8341 P-2

Physics

Topic-2 : Dimensions of Physical Quantities 1

MCQs with One Correct Answer 黨

҈







�



䰘

㡰 

҈

E ҈    z =   B CR m e  �  犨  C㜠ᆠᆠ� ᆠR㜠 矄�矄 ᆠl㜠 �  E㜠쟼ᆠ�ᆠ � B㜠鼀� �ᆠ �   e   m   㜠 矄ᆠ 鼀���泐 鼀��泐矄ᆠ�泐   ᲼㝐� 和� ᔼᔼ㡰桌 㡰 x, y z  矄鼀 �鼀 矄�ᨨ  㡰 졠 泐x z  矄鼀 �鼀 矄�ᨨ  ᆠ㡰 졠 泐x  y  矄鼀 �鼀 矄�ᨨ  㡰 졠 泐y z  矄鼀 �鼀 矄�ᨨ  �鼀 矄�ᨨ  ᨨ鼀盐 ᨨ 鼀ᆠᨨ 盐ᆠ��泐�矄 K  ᨨ矄 鼀盐 ᲼㝐� 和 ᔼ㡰桌 㡰 㝐 ⧤ 㡰 㝐 ⧤ ᆠ㡰 㝐 ⧤ 㡰 㝐 ⧤҈ 꾀⼄盐 �泐x�矄�� 泐 IFv⏌WL㡰� 鼀矄ᨨ 鼀ᨨ鼀 ᨨ � �I ᨨᆠFᨨᆠ�泐v犨ᨨ├W  � L  �鼀 矄�ᨨ  ᨨ鼀盐 ᨨx�矄矄鼀矄 ᨨ  ᲼㝐� 和 ᔼᔼ㡰桌 㡰  ᆠ├矄ᆠᨨ 矄  㡰 ᨨᆠ ᆠᨨ 矄  ᆠ㡰  �泐  矄�泐 㡰 ᆠᨨ �ᆠ� ᨨ �矄ᆠᨨ矄�泐 꾀鼀ᨨ盐  ᨨ 矄ᨨ  �泐ᆠ� ᨨ    Ἐ矄矄盐 ᆠ  盐 � 盐 ��鼀�矄  �  矄ᨨ ᆠᨨ 矄  �鼀 矄�ᨨ ᨨ 矄ᨨᆠᨨ 矄 �矄᲼㝐� 和 ᔼᔼ㡰桌 㡰 㝐  㡰 㝐  ᆠ㡰 㝐 ҈ 㡰 㝐  ᔼ 矄 꾀  ᨨᆠ ᆠ ᨨ矄 矄 盐 鼀  盐 �矄    �鼀 矄�ᨨ ᨨ Ӹᨨ盐 �Ἐ矄鼀ᨨ 盐盐矄犨� ᲼㝐� 和 ᔼ㡰桌    ҈ ᆠ㡰 꾀 㡰 꾀҈ 㡰 꾀  㡰 꾀  ᔼ 鼀ᨨ鼀 盐鼀 㡰 꾀㡰 �鼀 㡰├ ᨨ  盐 鼀 ⼄盐 ��矄    �鼀 矄�ᨨ  ᨨ鼀盐 ᨨ  �泐�矄 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 ᲼꾀 桌 㡰 ᲼꾀҈ 桌 ᆠ㡰 ᲼꾀҈⏌  -҈ 桌 㡰 ᲼҈⏌ 꾀 -҈桌 ␔ �ᆠ ᨨ   ᨨᨨ犨� �ᆠᨨ鼀� �ᨨ 矄 矄  �鼀 矄�ᨨ

ᨨ ᆠ�ᆠ矄�矄 ᆠ Î0�矄 鼀���泐ᨨ ᆠ盐盐鼀  m�矄 鼀��泐ᨨ ᆠ盐盐鼀㡰䁸 ᲼㝐� ҈꾀�҈黨 ᔼ㡰桌

 ⼄盐 ��矄 x =

m m  㡰 e e

 y=

ᆠ㡰

e m

e 㡰 m 

ᔼ   ᨨ鼀盐㦨�Ӹ    �鼀 矄�ᨨ 矄ᨨ ᆠᆠ� ᆠ 鼀� �ᆠ �  矄ᆠ�泐 ␔     �鼀 矄�ᨨ 矄ᨨ Ӹ� 和ᔼ盐 �矄䁸 ᲼㝐� ҈꾀�҈黨 ᔼᔼ㡰桌 㡰 ᲼㝐҈ 꾀桌 㡰 ᲼㝐 꾀桌 ᆠ㡰 ᲼㝐 꾀桌 㡰 ᲼㝐 꾀桌

ᔼ 和ᔼ盐 �矄  �鼀 矄�ᨨ 矄ᨨ 

Î �矄 m

᲼㝐� 꾀�҈黨 ᔼ㡰桌 㡰 꾀 㝐҈҈ 㡰 꾀 㝐  ⏌ ᆠ㡰 꾀 㝐 㡰 꾀 㝐҈ ҈  l r c   v 矄  � 盐ᆠ ᆠ 矄�矄 ᆠ ᆠᆠ� ᆠ ᨨ�矄ᆠ�泐  �鼀 矄�ᨨ ᨨ 



l � 和ᔼ盐 �矄犨� ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌 rcv 㡰 ᲼꾀桌 㡰 ᲼꾀҈ 桌 ᆠ㡰 ᲼ 꾀桌 㡰 ᲼ 桌  ᨨᆠᨨ � ᆠ�ᨨ  犨  犨ᨨᨨ鼀矄�矄��  泐 ҈҈ æ x ö F = ab   ç ç akT ÷÷ 錐 犨  x �矄   �矄 ᆠ ├�矄   è ø ᨨ 鼀

ᆠᨨ 矄   �矄鼀盐 a b 犨ᨨᆠᨨ 矄 矄  �鼀 矄�ᨨ 矄ᨨ b�矄 ᲼㝐� ҈҈ ҈黨 ᔼ㡰桌 㡰 㝐   㡰 㝐  ᆠ㡰 㝐  㡰 㝐   ҈ ᔼ 矄  㡰ᆠᆠ�ᨨ  꾀㡰  ᨨᆠ 㡰ᆠᨨ 矄�  矄 盐 鼀 盐 �矄  �鼀 矄�ᨨ ᨨ Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 犨� ᲼㝐� ҈҈ ҈黨 ᔼᔼ㡰桌 㡰  꾀  㡰 꾀  ᆠ㡰  꾀 㡰 꾀 hc� 犨 ᆠ�矄矄 ᨨ G �� ෌盐 �矄���ᨨ ᆠᨨ 矄  h�矄  ᆠ├矄 ᆠᨨ 矄 �鼀 矄�ᨨ ᨨ f�矄 ᨨ ᲼㝐� 黨 ҈黨 ᔼ㡰桌 㡰  㡰  �泐 ᆠ㡰 鼀ᨨ鼀 盐鼀 㡰 ᨨ盐鼀 ҈ 쟼 矄矄�ᨨ  ᨨ�鼀� 鼀矄ᨨ ෌ 盐 �矄���ᨨ  ᆠᨨ 矄 㡰   ᆠ├Ἐ矄ᆠᨨ 矄 㡰 ᆠ 矄 ᨨ �� 㡰�矄 ᨨᨨ�ᨨ ᨨ ᲼㝐� 黨 ҈黨 ᔼᔼ㡰桌

҈ 꾀⼄盐 �泐f�矄�� 泐f㦨

㡰

ᆠ� ෌

㡰

ᆠ ෌

ᆠ㡰







ᆠ ᆠ ҈�  �鼀 矄�ᨨ 矄ᨨ 矄ᨨ� �ᨨ �V�  ᨨᨨᆠ�ᆠ  ᆠ� 盐 �矄ᨨ  ᆠ├sᆠᨨ 矄 �h矄 ᨨ �� �c  ෌��ᨨ ᆠᨨ 矄 �G 鼀A�矄 ᲼㝐�  ҈黨 ᔼ㡰桌 㡰 h⏌c�⏌G҈⏌A҈ 㡰 h⏌G⏌c⏌A҈ ᆠ㡰 h⏌e҈⏌G⏌A҈ 㡰 hG⏌C҈⏌A҈ ҈



B 犨 B�矄鼀� �ᆠ �  m0 m �矄 鼀� �ᆠ鼀��泐ᨨ ᆠ盐盐鼀�矄 ᲼㝐�  ҈黨 ᔼᔼ㡰桌 㡰 㝐  㡰 㝐 ҈ ᆠ㡰 㝐  㡰㝐҈   �鼀 矄�ᨨ 矄ᨨ 

WWW.JEEBOOKS.IN

P-3

Physical World, Units and Measurements

҈䰘

ᆠ ᆠ�矄�ᆠ �矄 ᆠ犨 �ᆠ ⼄盐 盐鼀���ᨨ   ᆠ矄矄�� � �ᆠ   ᆠ├ � ᆠ  鼀�  ᨨ鼀矄盐�ᆠᨨ鼀� �ᨨ ᨨ   盐 鼀  泐矄�ᆠ ᆠᨨ 矄 矄෌  ᆠ␔ �ᆠ  ᨨ   ᨨᨨ犨� �ᆠᨨᆠ泐 ��矄  ᆠ├ � 䁸 ᲼㝐� 졠 � 꾀�҈�҈桌 ҈

҈

҈黨



҈

҈ æ ෌ ö    㡰 ෌ ᆠ 㡰 ç  ÷ ᆠ㡰   ᆠ 㡰 ෌ ᆠ ෌ èᆠ ø

�鼀 㡰 ᨨᆠ�泐 ᔴ㡰  �盐 鼀ᨨ鼀 盐鼀 㡰 ᆠ ᨨ矄 矄 盐 鼀 ⼄盐 ��矄� 矄 ᨨ 鼀矄矄 �  �鼀ᔼ 鼀矄ᨨ  矄  �鼀 矄�ᨨ 矄ᨨ 鼀矄矄犨ᨨ盐  ᲼㝐� 졠 � 꾀�҈䰘桌 㡰 ᲼㝐桌㦨᲼ ҈ᔴ 桌 㡰 ᲼㝐桌㦨᲼ ҈ᔴ 桌 ᆠ㡰 ᲼㝐桌㦨᲼ ҈ᔴ ҈桌 㡰 ᲼㝐桌㦨᲼ ᔴ 桌 ᔼ   ᨨᨨ犨� �ἘᔼἘ 矄ᨨᆠ盐   ᨨ 矄泐鼀ᨨ矄   � 盐矄盐 鼀 � � ᔴ ᨨᨨ矄   ᨨ�ᨨ    ᆠᨨ矄ᨨ 矄ᨨ  �鼀 矄�ᨨ 矄ᨨ ᆠ�ᆠᆠᨨ 盐ᆠ��泐 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 㝐҈   ᔼ 㡰 㝐҈   ᔼ ҈   ᆠ㡰 㝐  ᔼ 㡰 㝐  ᔼ ᔼ ᆠᨨ �ᆠᆠ �ᆠᨨ 鼀矄矄鼀矄 ᨨ �� �

ᆠ盐盐鼀ᆠ  ᆠ├矄ᆠᨨ 矄  ├ 矄 盐 鼀  ⼄盐 ��矄 鼀��泐ᨨ ᆠ盐盐鼀mᆠ  矄矄 � 盐 �矄ᨨ   ᲼㝐� 졠 � 꾀�҈҈҈�桌

æ 鼀ᆠ ö æ ᆠ ö æ ö æ ö 㡰 ç  ÷ 㡰 ç  ÷ ᆠ㡰 ç  ÷ 㡰 çç  ÷÷ è 鼀 ø è ᆠ ø è  ø è 鼀 ø ᔼ  ᆠᆠ� ᆠᨨ   ᨨᆠᆠ�ᨨ�矄鼀矄盐 � 鼀矄 ᨨ 盐 ��u鼀 泐ᆠᨨ鼀� � � ᆠ�ᆠᆠ ��e ᨨ  �盐矄� ᆠ├矄ᆠᨨ 矄 �  矄 ᨨ ��  �c   ᲼㝐� 졠 � 꾀�҈҈�桌 ᆠ    ᆠ  㡰 盐 =  ᆠ㡰 盐 = 㡰 盐 = ᆠ      ᨨ鼀  ᨨᨨ犨� �ᆠᨨ鼀� �ᨨ 矄ᨨ  泐矄�ᆠᆠᨨ 矄 矄  矄矄   ᨨ盐�   � 盐矄盐 矄泐鼀ᨨ矄㡰   ᨨ 泐 ᆠᨨ鼀� �ᨨ  犨ᨨ盐   矄鼀盐�  �   矄泐矄鼀矄ᨨ 盐 �矄�矄 ᲼㝐� 졠 � 꾀�҈҈桌

 ᲼ Î 桌  ᨨ  �鼀 矄�ᨨ  ᨨ鼀盐ᨨ  鼀���泐 ᨨ ᆠ盐盐鼀 ᔼ 㝐 㦨 鼀矄矄  㦨  �   㦨 �鼀  꾀㦨ᆠ�ᆠᆠ盐    ᲼㝐� ҈桌 㡰 Î 㦨᲼㝐҈

꾀桌 㡰 Î 㦨᲼㝐҈

꾀桌 ᆠ㡰 Î 㦨᲼㝐҈

҈꾀桌 㡰 Î 㦨᲼㝐҈

҈꾀桌 �  �鼀 矄�ᨨ 矄ᨨ  �盐鼀ᨨ鼀 盐鼀   ᆠᆠ� ᆠ矄ᆠ�泐 ᲼㝐� 졠 � 꾀�҈桌 㡰 㝐 ҈꾀    -  㝐 -҈-  㡰 㝐 -     㝐 -҈-  꾀  ᆠ㡰 㝐 -҈  -  㝐 꾀  

䰘



㡰 盐 = 

㡰

㡰

ᆠ㡰

2

 peᨨ 



pe ᨨ ෌鼀

 鼀㦨鼀矄矄ᨨ ᆠᨨ 㡰

m ᨨ eᨨ ෌

ᆠ  

p m ᨨ eᨨ ෌ ᆠ  ᔼ 鼀矄ᨨ 矄�矄 ᆠ  �鼀   �鼀 矄�ᨨ 矄ᨨ �ᨨ m ᨨ  鼀��泐m 鼀���泐e�矄 e ᲼㝐� 졠 � 꾀�҈҈҈桌 㡰 ᲼ 桌 㡰 ᲼  ҈桌 ᆠ㡰 ᲼ 桌 㡰 ᲼  桌 㡰





黨

㡰 㝐 -҈   -  㝐 -҈-  꾀  ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄  �   �鼀 矄�ᨨ 矄䁸 㡰 矄矄盐Ӹᨨ盐 �矄鼀ᨨ 盐盐矄和矄矄 ᲼�和桌 㡰 쟼㝐 ᨨ � �  ᆠ쟼ᆠ�ᆠᨨ � ᆠ㡰 ␔ᨨ├ ᨨ 쟼 �泐 㡰 �ᨨ鼀ᨨ鼀 쟼ᆠ�ᆠ 盐 쟼ᆠ�ᆠ � a az 矄矄盐  矄 ᨨ  �矄 ᆠ 矄 P =   æç - ö÷  è kq ø b 犨 abᆠᨨ 矄 矄z�矄 �矄 ᆠk�矄ᨨ 鼀 矄 ᆠᨨ 矄  q�矄鼀盐  �鼀 矄�ᨨ ᨨ b ᲼和桌 㡰 MLT 㡰 M҈L҈T ҈ ᆠ㡰 MLT 㡰 M҈L҈T  DV 꾀 ⼄盐 �泐 X �矄 ��  泐 e  L  犨  Î  �矄   Dt 鼀���泐ᨨ   矄ᆠL �矄 � DV�矄ᨨ � �  ᆠ Dt�矄�鼀�   �鼀 矄�ᨨ  ᨨ鼀盐 ᨨX �矄 矄鼀矄 ᨨ ᲼҈和桌 㡰 矄�矄 ᆠ 㡰 ᆠ � ᆠ㡰 ᨨ� 㡰 ᆠ盐  æ ҈ö

 �鼀 矄�ᨨ  ᨨ  ç ÷ e  E   e   鼀���泐ᨨ   è ø 矄ᆠEᆠ�ᆠ � 㡰 ᲼和桌 㡰 MLT҈ 㡰 MLT ᆠ㡰 ML҈T 㡰 MLT҈ Integer Value Answer

 ᨨ �   �矄 ᆠd ᨨ犨 �ᆠ  矄��  ᆠ 矄

ᆠ泐 �  ᨨ��泐 ᆠᨨ ��ᨨ 矄  �犨泐矄㜠 ��  盐矄矄 �鼀 矄�ᨨ 矄   矄矄盐鼀矄     �矄 ᆠ  矄 ᨨ

 鼀矄矄  矄�泐rᨨ   ᨨ��  矄�泐 ᨨ犨⏌㡰Sᨨ  ��  ᨨ鼀 矄��  �矄 ⼄盐 ᆠ泐f  ��  � 矄 d�矄ᨨᨨ�ᨨ ᨨS҈⏌n 盐ᨨ n�矄 ᲼꾀 ҈桌 4

Fill in the Blanks

҈  �鼀 矄�ᨨ ᨨ ᆠ�ᆠᆠᨨ 盐ᆠ��泐�矄힘힘힘힘힘힘힘힘힘 ᲼҈黨黨䰘㜠҈㝐├桌   ⼄盐�ᨨ  ᨨ  矄 ᨨ  �矄 �矄 ��  泐 æ a ö çè P +  ÷ø V - b㡰 = RT   �鼀 矄�ᨨ 矄ᨨ  ᆠᨨ 矄  V a�矄힘힘힘힘힘힘힘힘힘 ᲼҈黨黨䰘㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-4





Physics

ᔼ   ᨨ鼀盐X㦨YZ X Z  �鼀 矄�ᨨ 矄ᨨ ᆠᆠ� ᆠ   鼀� �ᆠ � 盐ᆠ�ᨨ  矄ᆠ�泐  �鼀 矄�ᨨ 矄 ᨨ  Y �  MKSQ 矄泐鼀  힘힘힘힘힘힘힘힘힘 힘힘힘힘힘힘힘힘 ᲼҈黨㜠㝐├矄桌  ᆠ├矄ᆠᨨ 矄  矄 �鼀 矄�ᨨ 힘힘힘힘힘힘힘힘 ᲼҈黨�㜠㝐├矄桌 6

�

MCQs with One or More Than One Correct

和ᨨ鼀�鼀矄��矄ᆠᨨ  � ᨨᆠᨨ 矄盐ᆠ矄泐矄鼀ᨨ 盐 �矄 矄ᨨ ⼄盐 ��矄ᆠ  矄矄 � 鼀矄ᨨ ᨨ 泐ᨨ   泐矄�ᆠ ⼄盐 �泐 ᔼ  ᨨ  矄盐ᆠ  矄泐矄鼀 �鼀 矄�ᨨ 矄 ᨨ �  ⼄盐 ��矄�� � 鼀矄ᨨ ⼄盐 �泐X矄 ᨨᨨ犨矄 ᲼ᨨ矄��ᨨ 桌㦨᲼Xa桌錐᲼矄 桌 㦨᲼Xb桌錐᲼ᆠᆠ�ᨨ 桌㦨᲼Xp桌錐 ᲼� 鼀ᨨ鼀 盐鼀桌㦨᲼Xq桌錐᲼ ᨨᆠ桌㦨᲼Xr桌  ᲼꾀 桌 㡰 a + p = b



䰘



黨

ᆠ㡰 p - q + r = a 㡰 p + q + r = b  盐矄 ᆠᨨ 矄�   矄泐矄鼀 ᨨ  盐 �矄 �  犨 �ᆠ  鼀矄矄   �盐 鼀ᨨ鼀 盐鼀  �鼀 矄�ᨨ 矄矄 ᔼ   �  矄 �鼀 矄�ᨨ 矄ᨨ 犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄⏌ ᆠᨨᆠ䁸 ᲼꾀 ҈黨桌  㡰  �鼀 矄�ᨨ ᨨ  ᨨᆠ�矄L 㡰  �鼀 矄�ᨨ ᨨ � 鼀ᨨ鼀 盐鼀�矄L҈ ᆠ㡰  �鼀 矄�ᨨ ᨨ  �泐�矄L 㡰  �鼀 矄�ᨨ ᨨ ᨨ犨�矄L� 꾀 � 矄ᆠ l㡰  矄ᨨ    鼀���泐 e㡰 ᨨ  �ᆠ�ᆠ鼀�ᨨ 鼀

ᆠᨨ 矄  ├㡰 矄ᨨ盐 鼀盐 㡰  盐鼀盐 �ᨨ盐鼀 㡰ᨨ ᆠ�

ᆠ � �ᆠ矄  ᆠ � ⼄㡰ᆠ� 泐ᆠ ᨨ  �ᆠ矄␔ �ᆠ ᨨ   ᨨᨨ犨� � 矄矄�ᨨ 矄㡰 ᨨI �矄 㡰 �鼀 矄�ᨨ 泐ᆠᨨᆠ䁸 ᲼꾀  ҈桌

æ ⼄ ö l = ç ÷ 㡰 ç e├  ÷ è ø

æ e├  ö ÷ 㡰 l = çç  ÷ è ⼄ ø

æ ö ⼄ ÷ ᆠ㡰 l = çç ⏌ ÷ è e ├  ø

æ ö ⼄ ÷ 㡰 l = çç ҈⏌ ÷ è e ├  ø

ᔼ  鼀矄 ᨨ  ᨨ � �  ᆠ V ᆠ�ᆠ ᆠ盐  I 鼀���泐e鼀��泐m 矄 ᨨ �� c  �鼀 矄�ᨨ 泐ᆠᨨᆠ⼄盐�ᨨ 矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 mᔼ㦨e 㡰 mᔼ㦨m ᆠ㡰 ᔼ㦨eᆠ 㡰 mᆠᔼ㦨e  ᆠ├矄ᆠᨨ 矄  h 矄 ᨨ ��  c   ���ᨨ  ᆠᨨ 矄 G盐矄 ᨨ ᨨ鼀盐 �ᨨ  � L 盐 �ᨨ 鼀矄矄M   ᆠᨨᆠᨨ�ᨨ 矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 Mµ c 㡰 Mµ G ᆠ㡰 Lµ h



㡰 p + q - r = b

㡰 Lµ G

 [e 0 ]   ᨨ  �鼀 矄�ᨨ  ᨨ鼀盐ᨨ  鼀���泐 ᨨ  ᆠ盐盐鼀  [m 0 ]  ᨨ  鼀��泐ᨨ   ᆠ盐盐鼀ᔼ M㦨鼀矄矄L㦨 � T㦨�鼀 I㦨ᆠ�ᆠ ᆠ盐  ᲼҈黨黨㜠㝐├矄桌

㡰 ᲼e  桌 = M -҈ L- T  Ι 㡰 ᲼e  桌 = M -҈ L- T  Ι  ᆠ㡰 ᲼m  桌 = M LT - Ι - 㡰 ᲼m  桌 = M LT -҈ Ι ҈  �矄 ᨨ   泐矄�ᆠ ⼄盐 ��矄      矄鼀 �鼀 矄�ᨨ 矄�矄 㡰 ᲼҈黨黨�和桌 㡰 泐 ᨨ 矄 盐鼀 ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ

㡰 ᔴ盐�  ⼄盐 ᆠ泐ᨨ �� 犨 ᆠ㡰    ���ᨨ ᨨ � 㡰  ᆠ├矄ᆠᨨ 矄  ᨨ⼄盐   �鼀 矄�ᨨ 矄ᨨ  ⼄盐 ��矄� ᨨ  ᨨ鼀ᨨ㡰ᨨ   ᨨᨨ犨� ��矄 矄鼀ᔼ  � 泐 � 矄㡰 㡰 ᨨ⼄盐 ␔ᨨ├ ᲼҈黨㜠㝐├矄桌 㡰 꾀 �盐鼀ᨨ鼀 盐鼀 ␔ᨨ├ ᆠ㡰 쟼 �泐 Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 㡰 �� 泐 ␔ � 7

Match the Following

 㝐ᆠ  �矄 ᔼ犨�  �矄 ᔼᔼ  矄ᆠ   ᆠᨨᆠ  矄犨 盐矄� � ᆠᨨ 矄�� ᨨ犨 �矄矄 ᲼꾀 ҈桌 �矄ᔼ �矄ᔼᔼ  ᨨ 鼀

ᆠᨨ 矄  ҈ ᲼㝐 㜠҈桌 턼 ᔴᨨ �ᆠ� ᨨ �矄ᆠᨨ矄�泐  ᲼㝐҈ ҈桌   ᆠ├ᆠᨨ 矄   ᲼㝐 ⧤҈桌 和 鼀ᆠᨨ 盐ᆠ��泐  ᲼㝐 ⧤҈桌 ᔴᨨ 矄  턼 和 㡰  ҈   㡰   ҈  ᆠ㡰   ҈  㡰  ҈    㝐ᆠ     泐矄�ᆠ ⼄盐 ��矄 ��  �  ᆠᨨ盐鼀  ᔼ 犨� �鼀 矄�ᨨ 矄 矄矄 � 鼀矄ᨨ 鼀矄矄 M㡰 �  L㡰 �鼀 T㡰 ᆠ � Q㡰�� � ᆠᨨ盐鼀 ᔼᔼ 犨�  ᆠᨨᆠ 矄犨�� 矄 鼀ᆠ  ⼄盐 �泐� 盐 ᨨ鼀� 泐ᨨ盐 矄犨ᨨᨨ├ ᲼҈黨㜠㝐├矄桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀 �盐鼀ᨨ鼀 盐鼀 MLT    MLQ

ᨨ⼄盐 MLT҈ ᔴᆠ� ᆠ MLT҈Q ᔼ 盐ᆠ ᆠ M ҈ L  T  Q 矄�矄��泐 LT  8

Comprehension/Passage Based Questions

矄矄� ᔼ ᆠᨨ鼀� �ᆠ ᨨ泐 ᆠ�ᆠ 鼀� �ᆠ  ᨨ鼀   ᨨᆠ ᨨ   ᨨ  �鼀 矄�ᨨ 矄ᨨ ᆠ�ᆠ  鼀� �ᆠ⼄盐 ��矄鼀盐矄矄ᨨ ᨨᆠ ᨨ ᔼ

 ⼄盐矄�ᨨ 矄ᨨ犨᲼E桌 ᲼B桌矄  ᨨ �鼀 矄�ᨨ 矄ᨨ ᆠ�ᆠ  鼀� �ᆠ � 矄矄ᆠ�泐犨 �᲼e桌 ᲼m桌矄  ᨨ �鼀 矄�ᨨ 矄ᨨ  鼀���泐 鼀��泐ᨨ  矄ᆠ 矄ᆠ�泐 ᲼L桌  ᲼T桌  �鼀 矄�ᨨ 矄 ᨨ  �    �鼀 矄ᆠ�泐꾀 ⼄盐 ��矄�� � 和ᔼ盐 �矄 ᲼꾀 ҈桌 � �ᨨ 犨 ᲼E桌 ᲼B桌�矄 㡰 ᲼E桌㦨᲼B桌᲼L桌҈᲼T桌 㡰 ᲼E桌㦨᲼B桌᲼L桌᲼T桌 ᆠ㡰 ᲼E桌㦨᲼B桌᲼L桌᲼T桌҈ 㡰 ᲼E桌㦨᲼B桌᲼L桌҈᲼T桌҈

WWW.JEEBOOKS.IN

P-5

Physical World, Units and Measurements



�ᨨ 犨 ᲼e桌 ᲼m桌�矄 㡰 ᲼m桌㦨᲼e桌᲼L桌᲼T桌 㡰 ᲼m桌㦨᲼e桌᲼L桌᲼T桌 ҈   ᆠ㡰 ᲼m桌㦨᲼e桌 ᲼L桌 ᲼T桌 㡰 ᲼m桌㦨᲼e桌҈᲼L桌᲼T桌



10 Subjective Problems 䰘

␔�  �鼀 矄�ᨨ 矄ᨨ   ᨨᨨ犨� �� 鼀矄ᨨ 鼀矄矄 �鼀 �  ᆠ � ᲼҈黨㜠㝐├矄桌

�㡰 鼀� �ᆠ 盐 ��㡰 ��� �泐鼀ᨨ 盐盐矄 꾀�矄盐 ᨨ鼀  ᨨ矄�ᨨ 盐 犨ᨨ矄ᆠ�矄 犨� �ᨨ Tᨨᨨ�ᨨ ᨨp a d b E c␔ �P�矄  矄�ᆠ矄矄盐�d�矄   矄�泐ᨨ 犨 �E�矄 ᨨ  �泐ᨨ   ᨨ矄�ᨨ  �  盐矄ᨨ ab c ᲼҈黨҈㜠㝐├矄桌

Topic-3 : Errors in Measurements & Experimental Physics 1 ҈





MCQs with One Correct Answer

꾀矄ᆠ犨�盐� 矄� ��矄�ᨨ 矄ᨨ �矄ᆠ�ᆠ盐矄ᆠ  ᆠ�ᆠ盐矄ᆠ�矄盐 �矄  ᨨ  �ᆠ 矄ᆠ鼀├� � �ᨨᨨ盐矄ᨨ ᨨ ᆠᨨ鼀ᨨ�ᨨ ᨨ  ᆠ�ᆠ盐 矄ᆠ �矄ᆠ鼀 ᨨ �鼀鼀�矄 ᨨ�ᆠ ᨨ  �ᆠ 矄ᆠ  盐 ᨨ  ᨨᨨ � ᨨ      矄 ᆠᨨ盐 ᨨ  矄ᆠ犨�盐�矄ᆠ�泐 ᲼㝐� 和 ᔼ㡰桌 㡰 ��m鼀 㡰 ᨨ矄��҈m鼀 ᆠ㡰 ᨨ矄��҈鼀鼀 㡰 ᨨ矄��҈m鼀 꾀矄盐  鼀矄盐� �  �鼀ᨨ  ᆠ�ᨨ ᆠ�ᆠ盐 ᆠᨨ矄矄㜠矄ᆠ�ᨨ 犨�   ᨨ  �矄ᆠᆠᨨ 矄  ᨨᨨ犨� � ᨨ盐  � �矄��鼀鼀���鼀鼀 ��鼀鼀 ��鼀鼀 �ᨨ  矄 ᨨ盐 � ��矄��䰘�鼀鼀   矄   ��ᨨ ᨨ   �矄䰘黨�鼀鼀  � �鼀ᨨ   ᆠ�矄 ᨨ盐   ᨨᆠᨨ  ᲼㝐� 和 ᔼᔼ㡰桌 矄 㡰 ��䰘�±䰘黨㡰鼀鼀 㡰 ��䰘�±䰘㡰鼀鼀 ᆠ㡰 ��±䰘㡰鼀鼀 㡰 ��±䰘㡰鼀鼀 꾀 泐矄�ᆠ⼄盐 �泐z  矄ᨨ  ᨨ盐ᨨ矄矄abc  d矄z㦨



�

   a b

 ᆠ �矄ᨨ ᨨ�  鼀㜠 cd  矄盐鼀 ᨨ abc d奠҈�奠奠 �奠㜠 矄ᆠ�泐 ᆠ �ᨨ ᨨ� z�矄 ᲼㝐� 和� ᔼ㡰桌 㡰 ҈�奠 㡰 ҈�奠 ᆠ㡰 ҈�奠 㡰 ҈�奠 矄� �矄ᆠ犨�盐�ᨨ �ᆠ ҈ᆠ鼀 � ��矄�ᨨ 矄ᨨ �矄 ᆠ�ᆠ盐矄ᆠ   �ᆠ├ 矄矄ᨨ   ᨨᆠ�矄 鼀矄盐 ᔼ 矄 ᨨ盐 ᆠᨨᆠ泐ᆠᨨ  矄[㝐� Sep. 03, 2020 (I)] 㡰 ҈҈ᆠ鼀 㡰 ҈ᆠ鼀 ᆠ㡰 ҈�ᆠ鼀 㡰 ҈ᆠ鼀

矄ᆠᨨ盐 ᨨ  鼀� 矄ᆠᨨ  �ᆠ�矄�矄 ҈鼀鼀ᔼ矄 �矄ᆠ�矄 ��  � ᨨ҈ ��矄�ᨨ 矄 ᆠᨨ� ᆠ� 犨� 黨 ��矄�ᨨ 矄ᨨ  鼀� 矄ᆠ␔  犨矄 ᨨ盐ᆠ � � ᆠ  ᨨ    䰘  ��矄�ᨨ  ᨨ   � 矄ᆠ ᆠᨨ� ᆠ� 矄犨�  ��矄�ᨨ ᨨ 鼀� 矄ᆠ   ᨨᨨ  �矄ᆠ�矄泐� ��� 矄� ᨨ   ᨨᨨ 鼀� 矄ᆠ ␔   �矄 ��矄盐矄 ᨨ鼀矄盐 � ᨨ ᆠ泐�    ᨨᨨ   �矄ᆠ犨 ҈ᆠ鼀 ᆠ鼀  和ᆠᨨ� ᆠ� 矄犨� 鼀� 矄ᆠ ��矄�ᨨ   � ᨨ  ᆠ泐� �矄 和�矄 �矄ᆠ ��矄�ᨨ 㡰 [㝐� Sep.02, 2020 (I)]

㡰 ᆠ鼀 㡰 ҈ᆠ鼀 ᆠ㡰 䰘ᆠ鼀 㡰 黨黨ᆠ鼀 ᔼ  矄ᆠ犨ᨨ 矄ᆠ犨㜠�盐��矄�� 矄� ᨨ�ᨨ 矄�鼀ᨨ矄 泐鼀鼀ᨨ  鼀� 矄ᆠᔼ  � ��矄�ᨨ 矄ᨨ   ᆠ�ᆠ盐矄ᆠ 矄ᆠᨨ盐 ᨨ  矄ᆠ犨�盐��矄 ᲼㝐� 黨  ᔼ㡰桌 㡰 ҈ᆠ鼀 㡰 鼀鼀 ᆠ㡰 ҈ᆠ鼀 㡰 ҈鼀鼀 䰘 ᨨ  ᨨ盐矄矄ᨨ  鼀矄盐  泐矄�ᆠ⼄盐 ��矄矄 �� ᨨ犨␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄�矄ᆠᨨᆠ䁸 ᲼㝐� 黨  ᔼᔼ㡰桌 꾀㡰 꾀҈㦨҈㦨䰘ᔴ҈㦨� 㡰 꾀㦨㦨҈ᔴ㦨 ᔴ㡰 꾀㦨�㦨҈黨҈ᔴ㦨҈ 㡰 꾀㦨�㦨҈黨҈ᔴ㦨҈黨� 㡰 꾀졔졔ᔴ꾀҈졔҈졔ᔴ҈꾀졔졔ᔴ꾀졔졔ᔴ 㡰 꾀҈졔҈졔ᔴ҈㦨꾀졔졔ᔴ㦨꾀졔졔ᔴ㦨꾀졔졔ᔴ ᆠ㡰 꾀졔졔ᔴ꾀҈졔҈졔ᔴ҈㦨꾀졔졔ᔴ㦨꾀졔졔ᔴ 㡰 꾀҈졔҈졔ᔴ҈꾀졔졔ᔴ꾀졔졔ᔴ꾀졔졔ᔴ  꾀矄�鼀 盐盐鼀�矄� �盐矄 ᨨ 鼀�  盐 ᨨ ���ᨨ ᆠᆠ�ᨨ gᆠ� ᆠ  � ᨨ   盐盐鼀�矄�ᆠ鼀  矄ᨨ犨ᆠ 犨�  ҈矄 矄ᨨ盐�ᨨ 鼀矄盐矄 �鼀├  ᨨᨨ矄ᆠ��ᨨ 矄ᨨ �矄 ᆠᆠ盐ᆠ泐� g�矄 ᲼㝐�   ᔼᔼ㡰桌 㡰 �奠 㡰 奠 ᆠ㡰 奠 㡰 奠 黨 ᔼ    矄�泐鼀矄盐鼀 ᨨ ᆠ盐 鼀矄矄  �  � 鼀矄盐 矄 ҈᠀҈㡰├�  ҈᠀҈㡰 鼀矄ᆠ�泐 ᨨ�  鼀矄盐鼀 ᨨ   矄�泐 �矄 ᲼㝐� 黨꾀�҈黨 ᔼ㡰桌 㡰 ҈├�⏌鼀 㡰 ҈├�⏌鼀 ᆠ㡰 ҈├�⏌鼀 㡰 䰘├�⏌鼀 ҈ ᨨ 矄⼄盐�矄�黨ᆠ鼀  ᨨ 䰘矄盐ᆠ 矄⼄盐矄├� �� ᨨᆠᆠᨨ盐  矄�� � �ᆠ  ��盐矄�矄 ᲼㝐� 黨꾀�҈黨 ᔼᔼ㡰桌 㡰 䰘ᆠ鼀 㡰 䰘ᆠ鼀 ᆠ㡰 䰘ᆠ鼀 㡰 䰘ᆠ鼀 ҈҈ ᔼ 矄�鼀 盐盐鼀 �鼀  ᨨ 鼀� �ᨨ ᨨ ᆠᆠ�ᨨ  盐 ᨨ ��泐 g㡰 �鼀 ├  ᨨ  ᨨ矄ᆠ��ᨨ 矄 �矄 鼀矄盐  泐盐矄� �  犨ᆠ  ᨨ  ҈ 矄ᆠᨨ 矄ᆠᨨ盐  鼀 盐ᨨ �鼀├ ᆠᨨ鼀矄ᨨ盐ᨨ  矄   �  ᨨ  盐盐鼀 �矄 鼀矄盐  泐盐矄� �  鼀矄ᆠᨨ 矄ᆠᨨ盐 ҈鼀鼀  盐ᨨ�  �矄 ��ᆠ鼀 ᆠ �ᨨ�   鼀� �ᨨ ᨨ g�矄 ᆠᨨ矄ᨨ ᲼㝐� 꾀�҈黨 ᔼᔼ㡰桌 㡰 䰘奠 㡰 奠 ᆠ㡰 �奠 㡰 奠 

WWW.JEEBOOKS.IN

EBD_8341 P-6

҈

҈

҈

҈�

Physics

矄ᆠᨨ盐 ᨨ  鼀� 矄ᆠᨨ 矄ᆠ犨�盐��矄҈鼀鼀

鼀� �鼀盐鼀 盐鼀ᨨ  ��矄�ᨨ 矄ᨨ �矄ᆠ�ᆠ盐矄ᆠ ⼄盐� ᨨ鼀矄盐�Ҙ鼀 �鼀ᨨ 犨��矄 ᲼㝐� ҈ ҈黨 ᔼ㡰桌 㡰 � 㡰  ᆠ㡰 ҈ 㡰 �

�ᆠ    盐鼀ᨨ  ��矄�ᨨ 矄 ᨨ  ᆠ�ᆠ盐 矄ᆠ ᨨ  ��  矄ᆠ犨 �盐�  � 鼀鼀   ҈ 矄ᆠ�泐 ␔     矄ᆠ犨 �盐� �矄 盐泐 ��   犨� ᨨ盐 泐ᨨᆠ   ᨨᨨ �矄 ᆠ�ᆠ盐 矄ᆠ �矄 ��矄�ᨨ ᨨ犨 鼀 � 

 � �矄ᨨ  鼀� 矄ᆠ  ᆠ�ᆠ盐矄ᆠ ᨨ   �  矄   �� 鼀鼀    矄ᆠ�泐    �ᆠ├ 矄矄 ᨨ    矄  �矄 ᲼㝐� 黨 ҈黨 ᔼᔼ㡰桌 㡰 �䰘��鼀鼀 㡰 �黨�鼀鼀 ᆠ㡰 �䰘�鼀鼀 㡰 �䰘鼀鼀

  矄�泐ᨨ   鼀� �    矄  ᨨ   ᆠ盐 �矄 鼀�  泐鼀矄盐� � 矄� 矄ᨨ  ᆠ盐 �矄 鼀矄矄ᔼ  �ᨨ矄� 鼀矄盐� � 鼀矄矄  �  矄ᆠ�泐҈�奠   ҈奠   鼀 �鼀盐鼀 ᨨ �

鼀� � �   矄�泐�矄 ᲼㝐� ҈桌 㡰 �奠 㡰 �奠 ᆠ㡰 �奠 㡰 奠

ᆠ �ᨨ矄� ⼄盐 ��矄턼  和�奠 ҈奠奠 ҈�奠矄ᆠ�泐�  鼀矄盐鼀 ᨨ   턼   和

鼀 �鼀盐鼀ᆠ �ᨨ�  盐ᨨ 꾀犨� ᲼㝐� 졠 � 꾀�҈҈桌 㡰 �奠 㡰 奠 ᆠ㡰 䰘�奠 㡰 �奠 ᔼ 矄ᆠ犨�盐��ᆠᨨ鼀ᨨ�ᨨ 矄ᨨ  矄ᆠ犨ᆠ盐矄 �ᨨ鼀ᨨ�  �矄 ᆠᨨ �ᆠ鼀 ҈ᆠ�ᆠ盐 矄ᆠ ��矄�ᨨ 矄  �ᆠ├ 矄矄ᨨ 犨�鼀矄盐 泐 �矄 矄ᆠ犨�盐���矄 � �ᨨ 鼀� 矄ᆠ ��矄�ᨨ 矄 ᆠ�ᆠ盐矄ᆠ ��矄�ᨨ 矄꾀矄矄盐鼀� � ���� ᨨᨨ   �ᆠ├ 矄矄ᨨ  犨��矄 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰 ᆠ鼀 㡰 ҈�ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ҈�ᆠ鼀

 ᨨᨨ犨� �ᨨ矄�ᨨ 矄犨├  ᨨ 鼀� � � 矄盐 ᆠ 矄�ᨨ  ᨨ 犨泐ᆠ�泐鼀 ᨨ  �鼀ᨨ ᆠ�泐㦨҈�맔҈鼀 �矄ᨨ 犨 㦨҈�맔҈鼀 矄� ��㦨黨鼀⏌矄  矄�鼀� � �ᨨ

 泐矄�ᆠ⼄盐 �泐 꾀 =

҈

҈䰘

rhg ´҈ ⏌鼀 ᨨ矄矄�ᨨ� 矄盐 ᆠ 矄�ᨨ

 �矄ᆠᨨ矄矄ᨨ ᲼㝐� ҈䰘桌 㡰 奠 㡰 ҈奠 ᆠ㡰 ҈�奠 㡰 ҈�奠 꾀 泐矄�ᆠ⼄盐 �泐�矄 矄ᆠ� 泐 �ᨨ

㦨a҈⏌bᆠd ᔼ  �ᨨ矄�  鼀矄盐鼀 ᨨ a, b, c d 矄ᆠ�泐奠҈奠奠 �奠   � ᨨ� 犨� ᲼㝐� 졠 � 꾀�黨҈䰘桌 㡰 奠 㡰 ҈奠 ᆠ㡰 奠 㡰 �奠 T=

҈

҈黨 꾀矄ᨨ 鼀矄盐矄   ᨨ 犨泐鼀矄盐� �  �鼀� 犨  ᨨ� �矄ᨨ  ᆠ�� �  矄ᨨ盐 ᨨ �鼀ᆠ犨�  ᨨᨨ鼀ᨨ  犨 ᨨ�

�矄鼀矄盐鼀  ᨨ �鼀�矄d  㦨 ҈ 矄ᆠᨨ 矄    鼀矄盐矄   ᨨ  犨ᨨ㦨鼀矄 ├  ᆠᆠ�ᨨ  盐ᨨ��泐�㦨҈鼀矄  ᨨᆠ�泐 ᨨ 矄ᨨ盐  �矄  鼀矄҈     ᆠ�ᨨ ᨨ �    ᲼꾀 ҈䰘桌 鼀矄盐鼀 d⏌�矄ᆠᨨ矄矄ᨨ 㡰 奠 㡰 ҈奠 ᆠ㡰 奠 㡰 �奠  꾀矄ᆠ犨�盐�犨� �ᆠ ᨨ �鼀鼀 ᆠ�ᆠ盐矄ᆠ 犨� � ��矄�ᨨ 矄�矄盐矄 ᨨ鼀矄盐  �ᆠ├ 矄矄ᨨ   � 矄 ᨨ 꾀盐鼀� �盐鼀 ᨨ矄� � 鼀矄盐鼀  ��矄 ᨨ盐  犨  犨ᨨ犨矄ᨨ  矄ᆠ犨�盐� ᨨ盐� � ᆠᨨ ᆠ �  ��矄�ᨨ ᆠᨨ� ᆠ� 矄犨�   鼀� 矄ᆠ�    ᨨᨨ  鼀� 矄ᆠ�矄泐 �矄�␔ �矄  �ᆠ├ 矄矄ᨨ  矄 �  鼀� 矄ᆠ  � ��矄�鼀鼀  �  ��矄�ᨨ ᆠᨨ� ᆠ� 矄犨�   鼀� 矄ᆠ� 䁸 ᲼㝐� ҈桌 㡰 䰘鼀鼀 㡰 �鼀鼀 ᆠ㡰 䰘�鼀鼀 㡰 鼀鼀 ҈ 꾀矄盐  鼀矄盐矄 �鼀�ᨨ ᨨ ҈ᨨ矄ᆠ��ᨨ 矄ᨨ 矄�鼀 盐盐鼀 ᨨ盐�鼀矄  矄�矄黨矄黨҈矄黨� 矄 黨矄ᔼ  鼀� �鼀盐鼀 ��矄�ᨨ �  鼀矄盐� �ᆠᨨᆠ├ �矄҈矄   ᨨ 鼀 �鼀矄 ᨨ盐 ᲼㝐� ҈桌 㡰 黨 ᠀ ҈矄 㡰 黨 ᠀ 矄 ᆠ㡰 黨 ᠀ ҈�矄 㡰 黨 ᠀ �矄  犨ᨨ �ᆠ�矄ᨨ ᨨ 犨 �ᆠ  ҈ᆠ鼀 ��  � ᨨ҈⼄盐 ��矄�ᨨ 矄 ᨨ   鼀�  矄ᆠ   � 矄ᆠ ᨨ  ᨨ  ᨨ    ᆠ�矄 ᔴ҈㡰 矄 ҈ ⼄盐 ��矄�ᨨ 矄 ᆠᨨ矄ᨨ ᨨ黨鼀� 矄ᆠ ��矄�ᨨ 矄   �矄ᆠᨨ  ᨨ ᆠ� ᔴ㡰 矄҈⼄盐 ��矄�ᨨ 矄  ᆠᨨ矄ᨨ ᨨ҈҈鼀� 矄ᆠ ��矄�ᨨ 矄  � �矄 ᨨ  犨ᨨᆠ�矄矄 ᨨ犨 �   ��盐 鼀矄盐 盐矄 � ᆠ鼀㡰泐ᆠ�矄ᔴ҈ ᔴ矄ᆠ�泐 ᲼꾀 ҈桌 





ᔴ҈



 

҈





ᔴ



㡰 ᆠ㡰

�  䰘 



҈

㡰 䰘  㡰 䰘 䰘

 �ᨨ ᨨ ᨨ矄ᆠ��ᨨ ᨨ 矄�鼀 盐盐鼀�矄  㝐矄盐 盐ᨨ �矄ᆠ鼀├ ᨨ犨 ᨨ҈鼀鼀 � ᆠᆠ盐ᆠ泐 �鼀 ᨨ҈ᨨ矄ᆠ��ᨨ 矄ᨨ   盐盐鼀�矄 ᨨ盐 ᨨ黨矄盐矄� �犨�矄犨ᆠ ᨨ ҈矄矄ᨨ盐�ᨨ   ᆠᆠ盐ᆠ泐�   鼀� �ᨨ ᨨ ��矄 ᲼㝐� ҈�桌 㡰 ҈奠 㡰 �奠 ᆠ㡰 奠 㡰 奠

㦨 p

WWW.JEEBOOKS.IN

P-7

Physical World, Units and Measurements



�鼀ᨨ 矄�矄鼀矄盐 盐矄� � �ᆠ�矄 犨 �ᆠ  矄 ��矄�ᨨ 矄ᨨ ҈ᆠ鼀ᨨ �矄鼀� 矄ᆠ 㝐和㡰 ҈ ��矄�ᨨ 矄ᨨ �矄 �矄ᆠ 和㡰鼀ᆠ 黨 ��矄�ᨨ 矄ᨨ

 鼀� 矄ᆠ 矄盐ᆠ 鼀矄盐鼀 矄 ᨨ �� 矄 ᲼㝐� 졠 � 꾀�҈҈�桌 和ᨨ 㝐和 ᆠ鼀㡰 和 ��矄�ᨨ 矄

�

҈

�



 

� �

 



ᔼ   ᨨᨨ�矄ᆠ鼀  鼀 ᆠᨨᆠ  �鼀 �矄 㡰 �ᆠ鼀 㡰 �黨ᆠ鼀 ᆠ㡰 �ᆠ鼀 㡰 �ᆠ鼀

 ᆠ盐  ᨨ� �ᨨ  ᨨ   �ᨨ  �矄 ��  泐 ᔼ = ( ҈ - ҈) 鼀꾀 犨  �  ᨨ��矄 �



䰘



黨

ᨨ矄  鼀盐 �矄�  �├� ᔼ 矄盐   鼀├矄 ᨨ鼀矄盐� � ±҈ 犨 �鼀矄盐� �  ᆠ盐 ᨨ �鼀꾀⧤犨 犨� ᨨ�  盐 ᨨ ᆠ盐 � 鼀꾀䁸 ᲼㝐� ҈桌 㡰 鼀꾀 㡰 鼀꾀 ᆠ㡰 �鼀꾀 㡰 �鼀꾀 꾀矄盐  鼀矄盐   � ᨨ ᨨ  犨ᨨ�矄� ᆠ鼀␔ �ᆠ � 矄盐鼀  �  盐矄ᨨ鼀矄盐�䁸 ᲼㝐� ҈桌 㡰 꾀鼀矄ᆠ 㡰 꾀 �ᆠ�犨  ҈ ��矄�ᨨ 矄�  � 矄ᆠ鼀ᆠ 矄犨� 黨 ��矄�ᨨ � 鼀� 矄ᆠ 鼀�

矄ᆠ 矄҈ ��矄�ᨨ 矄� ҈ᆠ鼀 ᆠ㡰 꾀矄ᆠ犨�盐� � �҈ ��矄�ᨨ 矄�  ᆠ�ᆠ盐 矄ᆠ �ᆠ 矄҈鼀鼀 㡰 꾀矄ᆠ犨�盐� � �� ��矄�ᨨ 矄�  ᆠ�ᆠ盐矄ᆠ  �ᆠ 矄҈鼀鼀 ᔼ   �鼀 ᨨ ᆠ��ᨨ ᨨ ᨨ鼀矄  ᆠ ᨨ 鼀 ҈҈ᨨ�矄 ᆠ �� 矄ᆠ鼀ᨨ ᨨ �犨�

 ᨨ � �  ᆠ ᆠᨨ矄矄    矄 ᨨ 矄�矄 ᆠ �矄 ᨨ盐  ᨨ  ᆠ �� 矄  ᆠ鼀 ᨨ    犨�  ᆠᨨ矄ᨨ � � � �ᨨ ᨨ鼀�矄�ᨨ ᨨ�

  � �ᨨ ᨨ鼀犨� ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ҈�ᨨ 㡰 ҈�ᨨ ᆠ㡰 �ᨨ 㡰 �ᨨ 꾀   �鼀  �矄  ᨨ鼀  ᨨ ᨨ�    盐 ᨨ ᆠᆠ�ᨨ  盐ᨨ��泐�泐盐矄� �矄�鼀 盐盐鼀ᨨ  �   ᔼ   �矄 �鼀  �鼀 ᨨ ҈ᨨ矄ᆠ��ᨨ 矄 �矄 鼀矄盐 泐盐矄� �犨ᆠ ᨨ ҈矄ᆠᨨ 矄ᆠᨨ盐    盐�矄黨矄ᆠᨨ 矄  � �矄鼀矄盐 泐盐矄� � 鼀矄ᆠᨨ 矄ᆠᨨ盐 ҈鼀鼀  盐�矄ᆠ鼀  ᨨ�   鼀� �ᨨ ᨨ �犨ᨨ盐  ᲼㝐� 졠 � 꾀�黨҈桌 㡰 ҈䰘奠 㡰 䰘奠 ᆠ㡰 奠 㡰 䰘奠

 �鼀ᨨ ᆠ泐� �矄鼀矄盐 盐矄� � � ᆠ�矄犨�  ᨨ ᨨᨨᔼ�矄 ᨨ盐    ᨨᨨ    �矄ᆠ�矄犨 �҈ᆠ鼀 �҈�ᆠ鼀ᨨ  鼀�

矄ᆠ  �矄ᆠ 矄� ��矄�ᨨ 矄⼄盐� ᨨ�

҈





ᆠ鼀   ��矄�ᨨ ᨨ   �矄ᆠ ᆠ泐ᆠᨨ� ᆠ� 矄 犨� ᨨ ᨨ  鼀� 矄ᆠ ��矄�ᨨ 矄  �鼀ᨨ   ᆠ泐� �矄 ᲼꾀 ҈桌 㡰 �҈҈ᆠ鼀 㡰 �҈ᆠ鼀 ᆠ㡰 �҈ᆠ鼀 㡰 �҈ᆠ鼀 MLg ö æ ᔼ   鼀� �ᨨ ᨨ Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 ç Y = ÷ è pld  ø 泐盐矄� �和矄鼀 ᨨ 犨�ᨨ  � L㦨鼀 �鼀d㦨�鼀鼀�矄盐矄  ᨨᨨ M㦨�├�

  矄�ᨨ l㦨�鼀鼀�   � ᨨ  犨��矄ᨨ矄  턼盐 ��矄d l鼀矄盐 盐矄� �矄ᆠ犨�盐� 鼀�ᆠᨨ鼀矄ᆠ�泐 泐  矄鼀�ᆠ ᨨ �鼀鼀  盐鼀ᨨ  ��矄�ᨨ 矄ᨨ  �ᆠ�ᆠ盐矄ᆠ�矄 ҈ ᆠᨨ �盐�ᨨ 矄ᨨ 鼀 �鼀盐鼀ᨨᨨᨨ  Y鼀矄盐鼀  ᲼҈桌 㡰 盐 ᨨ   ᨨ矄 �    鼀矄盐鼀 矄 ᨨ  d  l 矄鼀 㡰 盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ d�矄犨�ᆠ  盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ l ᆠ㡰 盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ l�矄犨�ᆠ  盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ d 㡰 盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ d�矄 ᨨ盐�鼀矄   盐ᨨ ᨨ�  鼀矄盐鼀 ᨨ l

  矄�泐ᨨ   矄ᨨ�   �矄 ᨨ 鼀�   �  

 �鼀   �鼀ᨨ  �矄鼀矄盐 犨�  矄ᆠ犨�盐� 犨 ᨨ矄 �ᆠ  �矄 � 鼀鼀     � ��矄�ᨨ 矄ᨨ  ᆠ�ᆠ盐矄ᆠ  � �ᨨ  鼀�

矄ᆠ�矄�鼀鼀  ᨨ  ᆠ�ᆠ盐矄ᆠ�矄 ��矄�ᨨ 矄 ᔼ  鼀矄盐 鼀矄矄ᨨ   矄�ᨨᨨ 奠  �ᆠ �ᨨ�    矄�泐�矄 ᲼҈҈桌 㡰 黨奠 㡰 奠 ᆠ㡰 ҈奠 㡰 奠 꾀 �ᆠ�矄 矄҈鼀鼀鼀├矄ᨨ  鼀� 矄ᆠᔼ 矄 ⼄盐 ��矄�ᨨ 矄ᨨ   �矄ᆠ犨 �ᆠ 鼀ᆠ 犨� ҈ 鼀� 矄ᆠ ��矄�ᨨ 矄 ᨨ �矄 �ᆠ�矄 矄ᆠᨨ盐  ᲼҈桌 �矄 㡰 鼀鼀 㡰 �鼀鼀 ᆠ㡰 ҈鼀鼀 㡰 鼀鼀 和盐  矄ᔼᔼᔼ ᔼᔼᔼ ᨨ鼀  �鼀  ᨨ鼀矄盐� �  ᆠᆠ�ᨨ  盐ᨨ��泐 g㡰盐矄� �矄�鼀 盐㜠 盐鼀 泐盐矄 �   � 矄ᨨ   盐盐鼀 ⏌ᨨ ᆠᨨ �鼀 ᨨ �   盐鼀ᨨ ᨨ矄ᆠ��ᨨ 矄 ᨨ㜠 矄�ᨨ 矄矄 ᨨ犨 �   ᲼桌 矄ᆠᨨ盐  ᨨ � 㦨҈ᆠ鼀 矄ᆠᨨ盐  ᨨ�鼀㦨҈矄

和盐    � ᨨ   ᨨᨨ 

ᨨ�鼀  盐盐鼀 ᨨ矄ᆠ��ᨨ 矄 ᨨ 㡰 ᆠ鼀㡰 㡰 ᨨ矄ᆠ��ᨨ 矄 矄㡰 ᔼ   ҈ ᔼᔼ    ᔼᔼᔼ   

�鼀 �ᨨ  矄㡰 ҈ ҈ 黨

ᔼ EIEII EIII ᆠ �ᨨ矄� g� æ Dg ö çè g ´ ҈÷ø  ᨨ矄盐  矄ᔼᔼᔼ ᔼᔼᔼ矄ᆠ�泐 

㡰 EI㦨 ᆠ㡰 EI㦨EII

㡰 EI�矄鼀� �鼀盐鼀 㡰 EII�矄鼀 �鼀盐鼀

WWW.JEEBOOKS.IN

EBD_8341 P-8



�



Physics

꾀矄盐   ᨨ鼀矄  �鼀 ᨨ 鼀�  Ӹᨨ盐 �Ἐ矄 鼀ᨨ 盐盐矄ᨨ 犨� ᆠ泐鼀ᨨ �泐和Ἐ矄鼀 ᨨ ᔼ

�ᆠ盐 � � 矄盐  鼀矄盐矄   矄�ᨨ �

  � ᨨ  犨�ᨨ鼀鼀犨�  盐 ᆠ� 泐 ᨨ ±�鼀鼀ᨨ ᨨ  ᆠ泐҈├� 矄盐  矄ᨨ 鼀矄盐矄  �鼀ᨨ  犨�ᨨ鼀鼀犨� 

盐 ᆠ� 泐ᨨ ±҈鼀鼀 ├g㦨黨鼀⏌矄  ᆠ㡰  Ӹᨨ盐 �Ἐ矄鼀ᨨ 盐盐矄ᨨ�   ᨨ鼀  � ��矄 ᲼䰘桌 㡰 ±㡰맔҈҈҈⏌鼀 㡰 ±㡰맔҈҈҈⏌鼀 ᆠ㡰 ±҈㡰맔҈҈҈⏌鼀 㡰 ±�㡰맔҈҈҈⏌鼀 꾀矄盐   ᨨ鼀矄  �鼀  ᨨ 鼀� �ᨨ ᨨ æ p  l ö g ç =  ÷  ᨨ�  � l�矄Dl � �鼀T�矄DT è T ø   n �矄 盐鼀 ᨨ  �鼀矄   � � �矄 ├   鼀矄盐鼀 ᨨ g�矄鼀ᨨ矄ᆠᆠ盐 ᨨ ᲼㜠㝐҈桌 Dl DT n 㡰 �鼀鼀 矄ᆠ ҈ 㡰 �鼀鼀 矄ᆠ  ᆠ㡰 �鼀鼀 ҈矄ᆠ ҈ 㡰 ҈鼀鼀 ҈矄ᆠ � ᔼ  矄ᆠ犨�盐�   ᨨᨨ 鼀� 矄ᆠᆠᨨ� ᆠ� 矄犨� �   ��矄�ᨨ ᨨ ᆠ�ᆠ盐矄ᆠ�  ��盐 �㡰 ᆠ�ᆠ盐 ��矄�ᨨ ᨨ 矄ᆠ犨�盐��ᔼ鼀ᨨ矄�鼀鼀ᨨ 鼀�

矄ᆠ� ᨨ ᨨ�ᨨ   �鼀ᨨ  �  ��盐 ��㡰 �矄 ᲼㜠㝐҈桌 

҈ � 

��盐 �㡰 

 � 

��盐 ��㡰

䰘



㡰 �鼀鼀 㡰 鼀鼀 ᆠ㡰 ҈鼀鼀 㡰 ҈�鼀鼀 꾀犨�ᨨ  � l㦨±ᆠ鼀  �盐矄r㦨�±�ᆠ鼀  鼀矄矄m㦨±�鼀㝐 �鼀盐鼀ᆠ �ᨨ�

 矄�泐�矄 ᲼和桌 㡰  㡰  ᆠ㡰 ҈ 㡰  꾀ᆠ盐 矄矄� ᨨ  � ҈맔҈鼀ᔴᆠ盐�矄ᨨ盐鼀 㡰 ҈䰘맔҈鼀 㡰 ҈䰘맔҈鼀 ᲼和桌   ᆠ㡰 ҈䰘맔҈ 鼀 㡰 ҈䰘맔҈鼀 2

黨

Integer Value Answer

 �泐ᨨ 矄泐矄鼀矄 盐 ᆠ�ᨨ ᨨ �鼀�矄�� 矄 E t㡰㦨A  a㡰犨 a㦨矄҈ 鼀矄盐鼀 ᨨ A 矄 ᨨᨨ ҈�奠ᔼ  ᨨ�  鼀矄盐鼀 ᨨ �鼀�矄҈�奠 ᆠ �ᨨ�  盐ᨨ E t㡰 t㦨�矄�矄 ᲼꾀 ҈�桌

 盐� �和矄 �鼀  ᨨᨨ   �矄ᆠ�矄 犨 맔҈鼀 �맔҈鼀ᨨ  鼀� 矄ᆠ

  ��矄�ᨨ ᨨ   �矄ᆠ ᆠ泐ᆠᨨ� ᆠ� 矄 犨� ᨨ ᨨ  鼀� 矄ᆠ ��矄�ᨨ 矄␔    ��ᨨ  ᨨ ᨨ ├��矄� ᨨ 犨�  ᨨᨨ   � 矄ᆠ矄��矄犨 맔҈鼀 �맔҈鼀ᨨ  鼀� 矄ᆠ盐 ᨨ犨 �  ��矄�ᨨ ᨨ  �矄ᆠ ᆠᨨ� ᆠ� 矄犨� ᨨ ᨨ  鼀� 矄ᆠ ��矄�ᨨ 矄  � ᨨ   � 鼀�ᆠ犨��矄鼀 �矄ᆠᨨ矄矄㜠矄ᆠ�ᨨ  �矄맔҈䰘鼀 矄ᆠᨨ盐 ᨨ   �矄ᆠ�矄҈맔 ҈�鼀 鼀 �鼀盐鼀ᆠ �ᨨ�  Ӹᨨ盐 �矄 鼀ᨨ 盐盐矄ᨨ  犨��矄 ᲼꾀 ҈桌 3

Numeric Answer

҈   矄�泐ᨨ   矄ᨨ�  鼀 矄  �矄 鼀�   泐 鼀矄盐� ��矄鼀矄矄 �矄 �鼀 鼀 �鼀盐鼀ᨨ�

æ x ö    矄�泐ᨨ  矄 �矄 çè ÷ 奠ᔼ  �ᨨ矄 ҈ ø � 鼀矄盐� � 鼀矄矄   �鼀奠 ҈�奠 矄ᆠ�泐 盐ᨨ x�矄힘힘힘힘힘힘 ᲼㝐� 和 ᔼ㡰桌  犨ᨨᆠᆠ�ᨨ矄犨� ᆠᆠ� ᆠ盐矄C҈㦨᠀҈  C㦨᠀҈� ᆠᨨ

ᆠ � 矄�矄 ᨨ� � ᆠᨨ矄矄 �矄ᆠᨨ鼀� �ᨨ �矄V㦨�᠀  ᆠ �ᨨ�  ᆠᆠ盐�ᨨ ᨨ   �泐矄ᨨ �

 �矄ᆠᨨ鼀� �ᨨ ᨨ ᆠᆠ�ᨨ矄�矄힘힘힘힘힘힘힘᲼꾀 桌  꾀 ᨨ�ᆠ ᆠ  矄҈�鼀ᨨ �矄ᆠ � � ᨨ盐⼄盐 ��矄�ᨨ 矄� ᆠ ᆠ鼀␔ �鼀矄盐� �  ᨨᆠ � ᨨ ᆠᨨ   矄  矄�矄├䰘�ᆠ鼀鼀├ᨨ  矄ᆠ   ᨨᆠ� �矄├�ᆠ鼀鼀├ �鼀�ᨨ   ᨨᆠ �  ᨨ    ᨨ  矄�  ᨨ     矄 ᨨ矄 犨� �鼀��  �矄├҈�ᆠ鼀鼀├ᔼ  �矄 �鼀   ᆠ �ᨨ�  鼀矄盐鼀 ᨨ   ᨨᆠ � ᨨ   矄�矄힘힘힘 ᲼꾀 ҈黨桌  꾀矄 犨�ᨨ  �鼀�mm Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 맔҈҈҈N mᆠ�矄ᨨ ᨨ 鼀矄矄M  � ᨨ   犨�犨�  ᨨ �矄҈m꾀 �矄ᆠ犨� ҈ ��矄�ᨨ 矄 �矄ᆠ  ᨨ  ᨨ  �矄犨� ᨨ 矄犨��矄   ᆠ犨�ᨨ犨 �ᆠ 鼀� 矄ᆠᨨ 矄ᆠᨨ盐 ҈ mm �矄ᆠ   ҈ ��矄�ᨨ 矄 ᨨ    � 矄ᆠ ᆠᨨ矄ᨨ ᨨ黨 ��矄�ᨨ 矄ᨨ  鼀� 矄ᆠᔼ ��泐  ᨨᨨ  �矄ᆠᆠᨨ� ᆠ� 矄犨�   ᨨᨨ 鼀� 矄ᆠ ᔼ  ᨨ ᨨ  矄犨��矄� ᆠ矄 泐҈kg   �矄ᆠ ��矄�ᨨ 犨 �ᆠ ᆠᨨ� ᆠ� 矄犨� 鼀� 矄ᆠ ��矄�ᨨ �矄힘힘힘힘힘힘힘힘힘힘 ├�㦨҈m s p 㦨 ᲼꾀 ҈桌 � 矄� ᨨ ᆠ盐�矄鼀矄盐 泐 �ᆠ�矄 ҈ ��矄�ᨨ 矄ᨨ  �矄ᆠᆠᨨ� ᆠ� 犨� 黨 ��矄�ᨨ 矄ᨨ 鼀� 矄ᆠ犨 ҈ ��矄�ᨨ ᨨ 鼀� 矄ᆠ�矄҈鼀鼀㡰  鼀� 矄ᆠ 矄҈鼀鼀  �矄 ��矄�ᨨ ᨨ  �矄ᆠ ᆠᨨ� ᆠ� 矄犨�  鼀� 矄ᆠ㝐矄矄ᨨ  ᆠ盐�矄䰘� �    矄�泐ᨨ   ᆠ盐�  ᨨ�矄�� � �ᆠ  ᲼�㜠㝐├矄桌 ��盐矄  ᔼ  和矄  �鼀  犨 �ᆠ  �矄 盐矄  ᨨ � Ӹᨨ盐 �矄 㝐ᨨ 盐盐矄ᨨ 矄�ᆠ�泐  �鼀ᨨ  �鼀 犨��矄 D㦨�ᆠ鼀 鼀矄盐 泐矄ᆠᨨ 矄ᆠᨨ盐 ҈ᆠ鼀㡰   � �矄L㦨҈҈ᆠ鼀 鼀矄盐 泐矄ᆠᨨ 矄

WWW.JEEBOOKS.IN

P-9

Physical World, Units and Measurements

䰘

ᆠᨨ盐 ҈ᆠ鼀㡰꾀犨�� ᨨ �Nᆠ盐矄矄   矄�ᨨ ᨨ X 㦨 ҈�ᆠ鼀 鼀矄盐  泐 鼀�ᆠᨨ鼀 ᨨ 矄 ᆠᨨ盐  ҈ᆠ鼀㡰 � 鼀 �鼀盐鼀ᨨ矄矄�ᨨ�  盐矄ᨨ Ӹᨨ盐 �矄鼀ᨨ 盐盐矄和ᆠ犨�盐� 鼀矄ᆠ  ᨨ鼀ᨨ ᲼㜠㝐├矄桌 꾀矄ᆠ犨�盐� � �҈⼄盐 ��矄�ᨨ 矄 �ᆠ ᨨ  � ҈鼀鼀�矄盐矄 ᨨ鼀矄盐  �鼀ᨨ 犨�ᨨ  � �ᆠ鼀 鼀� 矄ᆠ � ��矄҈鼀鼀 䰘 ᆠ�ᆠ盐 ��矄�ᨨ ᆠᨨ� ᆠ� 矄犨�  鼀� 矄ᆠ �   ᆠ盐 矄盐 ᆠᨨ 犨�� ᆠ鼀ᨨᨨ�矄�� � �ᆠ  ��盐 盐矄 p = 6



 㡰 䰘

MCQs with One or More than One Correct Answer

ᔼ   �鼀 ᨨ 鼀�  ᆠᆠ�ᨨ  盐ᨨ�㜠 �泐�  ᨨ鼀盐盐矄  ᨨ �鼀�ᨨ ᨨ �ᨨ �ᆠ 鼀ᨨ�ᨨ �矄 = p

黨

�

᲼㜠㝐├矄桌

䰘 - 㡰  盐矄ᨨ    ��

鼀矄盐 ᨨ ᠀҈㡰鼀鼀  ҈᠀҈㡰鼀鼀矄ᆠ�泐 ᔼ  �矄盐ᆠᆠ矄矄�鼀矄盐鼀 矄 �鼀�ᨨ �矄 ᨨ盐 ᨨ�矄�矄�䰘矄�矄 �黨矄 矄ᆠᨨ盐 ᨨ  犨ᆠ 盐矄  ᨨ 鼀矄盐鼀 ᨨ �鼀�ᨨ �矄҈矄 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌 㡰 ᨨ�  鼀矄盐鼀 ᨨ �矄҈奠 㡰 ᨨ�  鼀矄盐鼀 ᨨ  �矄䰘�奠 ᆠ㡰 ᨨ�  鼀矄盐鼀 ᨨ  �矄奠 㡰 ᨨ�   鼀�  盐ᨨ ��矄҈҈奠 ᔴᨨ 矄�  �ᆠ�矄� 犨 �ᆠ ᆠ ҈ᆠ鼀ᨨ   鼀� 矄ᆠ�矄 ��  � ᨨ⼄盐 ��矄�ᨨ 矄 矄ᆠ犨 �盐�犨� ҈ ��矄�ᨨ 矄ᨨ �矄ᆠ�ᆠ盐矄ᆠᔼ   � ᆠ�矄� ��矄�ᨨ 矄ᨨ   �矄ᆠᆠᨨ� ᆠ� 犨�  ��矄�ᨨ 矄ᨨ  鼀� 矄ᆠ �  矄ᆠ犨�盐�ᨨ  ᆠᨨ鼀ᨨ�ᨨ ᨨ  ᆠ�ᆠ盐矄ᆠ鼀ᨨ矄�泐犨ᨨ ��矄�ᨨ 矄ᨨ  � 矄ᆠ   ᲼꾀 ҈�桌 㡰 ᔼ  �ᆠ ᨨ  矄ᆠ犨�盐��矄犨�ᆠ 矄ᆠᨨ盐  ᨨ   �ᆠ�矄 矄ᆠᨨ盐 ᨨ  矄ᆠ犨 �盐��矄҈鼀鼀 㡰 ᔼ  �ᆠ ᨨ  矄ᆠ犨�盐��矄犨�ᆠ 矄ᆠᨨ盐  ᨨ   �ᆠ�矄 矄ᆠᨨ盐 ᨨ  矄ᆠ犨 �盐��矄�鼀鼀 ᆠ㡰 ᔼ  矄ᆠᨨ盐 ᨨ  � 矄ᆠᨨ  矄ᆠ犨�盐� �矄犨�ᆠ 矄ᆠᨨ盐 ᨨ   �ᆠ�矄  矄ᆠᨨ盐 ᨨ  矄ᆠ犨�盐��矄҈鼀鼀 㡰 ᔼ  矄ᆠᨨ盐 ᨨ  � 矄ᆠᨨ  矄ᆠ犨�盐� �矄犨�ᆠ 矄ᆠᨨ盐 ᨨ   �ᆠ�矄  矄ᆠᨨ盐 ᨨ  矄ᆠ犨�盐��矄�鼀鼀 矄� �  矄矄�ᨨ  矄� q㦨lᨨ ᆠᆠ盐矄 盐矄 ᨨ  泐鼀矄盐� � ᆠᨨ矄ᨨ � � �矄q�   � ᨨ黨  犨 � l�矄 ᆠ泐├ ᨨ犨   ᨨ � q�矄ᆠᨨ 矄  ᨨ盐矄ᨨ q꾀矄q� ᆠ矄矄 ᨨ鼀 ᲼꾀 ҈桌

㡰 矄ᨨ盐ᨨ� d鼀� 矄ᆠᨨ 矄  㡰 矄ᨨ盐ᨨ� d� ᆠ矄矄 ᆠ㡰  ᆠ�ᨨ ᨨ� d鼀� 矄ᆠᨨ 矄  㡰  ᆠ�ᨨ ᨨ� d ᆠ矄矄 �҈ 꾀矄盐  盐矄矄矄�鼀 盐盐鼀ᨨ  ᆠ泐҈鼀 � ᨨ 鼀� g  ᆠᆠ�ᨨ  盐ᨨ��泐 盐矄矄  矄ᨨ犨ᆠ 犨�  矄ᆠᨨ盐 ᨨ ҈矄ᆠ ᨨ �矄 ᆠᨨ 矄 矄ᆠᨨ 矄 ᨨᨨ矄ᆠ��ᨨ 矄 ᨨ �矄ᨨ矄�ᨨ 犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼҈桌 㡰 쟼ᨨDT� 鼀矄盐� �T �鼀�ᨨ �矄�矄ᆠᨨ 矄 㡰 쟼ᨨDT� 鼀矄盐� �T �鼀�ᨨ �矄҈矄ᆠᨨ ᆠ㡰 ᆠ �ᨨ�   鼀� �ᨨ ᨨ g�矄�奠 㡰 ᆠ �ᨨ�   鼀� �ᨨ ᨨ g�矄�奠 8

Comprehension/Passage Based Questions

矄矄� ᔼ  鼀矄盐鼀 ᨨ矄�  �   ⼄盐 ��矄 ├ ᨨ犨     � �矄 ᨨ矄矄� ᨨ 鼀�    ᨨ �   泐   ⼄盐 �泐 �矄�矄 ᨨ 泐 盐矄ᨨ 矄�矄  矄�ᨨ

 盐 ᆠ� �   矄�ᨨ   �矄ᨨ犨ᨨ  ᨨ ᨨ  鼀ᆠᨨ 矄�  �ᨨ z㦨x⏌yᔼ  ᨨ矄� xy z DxDy Dz矄ᆠ�泐 



x ± Dx x æ Dx ö æ Dy ö z± Dz㦨 㦨 ç҈ ± ÷  ÷ ç҈ ± y ± Dy yè x øè y ø ҈

æ Dy ö

矄�矄  矄�ᨨ  ᨨ ç ҈ ± ÷  ᨨ �矄ᨨ犨� Dy⏌y�矄 y ø è ҈ m  Dy⏌y㡰 �ᨨ矄� �   �矄 犨泐矄  和ᨨ ᨨ� z犨� æ Dx Dy ö + Dz㦨 z ç ÷ y ø è x

ᨨ ��ᨨ 鼀├矄 矄矄盐鼀�ᨨ  Dx⏌x = ҈ Dy⏌y = ҈  ᨨ  �� ᨨ犨矄ᨨ  矄⼄盐 ��矄

�ᆠ  ᲼꾀 ҈桌 ҈  a 㡰 � ᔴᨨ 矄�    �ᨨ r =  ᨨ  鼀�   泐 ҈ + a 㡰 鼀矄盐� � �鼀 矄�ᨨ 矄矄⼄盐 �泐aᔼ  ᨨ�   鼀矄盐鼀 ᨨ a�矄Da Da⏌a = ҈  犨 �矄 ᨨ Dr�  鼀� � �r䁸 Da D a D a a D a 㡰  㡰  ᆠ㡰  㡰 ҈ + a㡰 ҈ + a 㡰 ҈  a 㡰 ҈  a  㡰 � ᔼ   �鼀  � �� 盐鼀ᨨ  �ᨨᆠ� 盐ᆠ��矄 ᔼ�矄 ᨨ盐  ҈᠀ 盐ᆠ� ᆠ泐 �   �矄 ҈矄 ᨨx = ҈ ҈졔x㡰㦨x盐ᨨ �矄ᨨ犨� x  ᨨDl�   鼀� �ᨨ ᨨ   ᆠ泐ᆠᨨ 矄 l�

s҈�矄 㡰  㡰  ᆠ㡰  㡰 ҈

10 Subjective Problems � ᔼ n  ��矄�ᨨ ᨨ 鼀� 矄ᆠᆠᨨ� ᆠ� 矄犨�  n졔҈㡰  ��矄�ᨨ 矄 ᨨ  �矄ᆠ෌� ᨨ 鼀� 矄ᆠ ��矄�ᨨ �矄⼄盐ᨨ �a盐 �矄 �  矄ᆠᨨ盐 ᨨ   � ᲼㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-10

Physics

Topic-4 : Miscellaneous (Mixed Concepts) Problems 8

Comprehension/Passage Based Questions

矄矄� 꾀  矄ᆠᨨᆠ�ᨨ ᨨ ⼄盐 盐鼀ᨨ ᆠᨨ 矄 ᨨ矄�� �ᨨ 矄�矄ᆠ  盐矄鼀ᔴ� 矄ᨨ� 矄ᆠᨨ � � � �  ᨨ矄�� �ᨨ 矄 矄盐ᨨ盐   泐  ᆠᨨ 矄 ᆠ     矄

盐矄鼀�  盐鼀  矄�泐ᨨ  ᆠᨨ 矄 ᆠ ᨨ 鼀矄矄�鼀␔   ᆠᨨ 矄矄盐ᆠ ᨨ ᆠ�ᆠ �  泐 �矄ᆠ �泐犨泐 ᨨ鼀  泐ᨨ矄�� �ᨨ 矄ᔼ  ᆠ�ᆠ � ᆠᨨ鼀矄 ᨨ ᆠᨨ 矄�� ᨨ ᨨ矄ᆠ�ᨨ盐 ᨨ矄���ᨨ 矄犨�  盐 �盐 ⼄盐 ᆠ泐 �w犨 �ᆠ  �矄 ᆠ    矄鼀 ⼄盐 ᆠ泐 ᨨ 矄盐矄�    ᨨ矄ᆠ��ᨨ 矄�鼀泐� �ᆠ�ᆠ �   矄ᨨ�   矄    �盐 ⼄盐 ᆠ泐 w 犨    ᨨ    �泐 �矄 矄ᨨ  ᨨ ��矄 ᆠ 꾀矄w ᨨᆠ 矄w 

ᆠᨨ 矄矄ᨨ矄ᨨ  ᆠᨨ�    �泐�矄  ᆠ  �矄�矄   �ᨨ ᨨ  ��  ᆠ��泐ᨨ 鼀矄 ᲼҈҈桌 ҈

├� � ᆠᨨ �ᆠᆠ �矄�  鼀���泐矄 �e矄 �鼀 矄�ᨨ  泐矄�矄ᨨ 鼀�  ᆠᨨᆠ  矄矄�ᨨ  ᨨw 㡰 

Ne 㡰 me 

me Ne

ᆠ㡰

Ne  me



Ne  me

쟼矄�鼀 犨 � 犨 �ᆠ 矄鼀 ᆠ�ᨨ 犨� ᨨᆠᆠ盐 ᨨ  鼀 � �    矄�泐 ᨨ  ᆠᨨ 矄 » ´ ҈䰘鼀 ├� �e㦨҈҈҈ 鼀矄矄鼀» ҈ 犨  矄⼄盐 ��矄� ᨨ和ᔼ盐 �矄 㡰  鼀 㡰  鼀 ᆠ㡰  鼀 㡰  鼀

Answer Key Topic-1 : Unit of Physical Quantities ҈ 㡰

 㡰

 ᆠ 㡰 Topic-2 : Dimensions of Physical Quantities

҈ ҈҈ ҈ ҈ 䰘

㡰  㡰 㡰 ҈ 㡰 㡰  㡰 ҈  ᲼㝐   꾀 桌  㡰  ᆠ㡰

 ҈   黨

ᆠ㡰  㡰 㡰 ҈ ᆠ㡰 ᆠ㡰  㡰 ҈  ᲼㝐   꾀 桌 ᆠ 㡰  ᆠ㡰

� ҈� �  ҈

㡰  ᆠ㡰 ᨨ 㡰҈ 㡰 㡰  㡰   ᲼㝐  턼 桌 ᆠ㡰

䰘 ҈䰘 䰘  

㡰  㡰 ҈ ᆠ㡰   ҈ ᲼㝐 桌  㡰 

㡰 㡰 㡰 ᆠ㡰

黨 ҈黨 黨 � �

㡰 ҈ 㡰  ᆠ㡰  㡰  ᆠ㡰 

㡰 ᆠ㡰 㡰 ᆠ㡰 㡰

Topic-3 : Errors in Measurements & Experimental Physics ҈ ҈   

㡰 㡰 㡰 㡰 㡰

 ҈҈ ҈ ҈ ҈

㡰 㡰 ᆠ㡰 ᆠ㡰 ҈�㡰

䰘 ᆠ鼀㡰

 ҈   

㡰 㡰 㡰 㡰 ҈㡰

 ҈   

㡰 ᆠ㡰 㡰 㡰 ҈黨㡰

� ҈   

ᆠ㡰 ᆠ㡰 㡰 㡰 㡰

  㡰 黨 ᆠ㡰 � 㡰

 ҈� � � �

㡰 䰘 ᨨ 盐矄㡰  㡰 ҈ 㡰 ҈䰘 㡰  㡰 䰘 㡰  ᆠ㡰 䰘 �ᆠ鼀㡰 

�҈ ᆠ㡰 � 㡰

ᆠ㡰 黨 ᨨ 盐矄㡰 㡰 ҈ ᆠ㡰 ҈黨 㡰 㡰  㡰 黨 㡰 㡰  㡰 黨 㡰 ҈黨맔҈҈⏌鼀㡰 æ  ö � ᆠ㡰 � ç ÷ è +҈ø

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈ ᆠ㡰

 㡰

WWW.JEEBOOKS.IN

P-11

Motion in a Straight Line

Motion in a Straight Line

2

Topic-1 : Distance, Displacement & Uniform Motion 1 ҈



꾀�ᆠ�矄鼀ᨨ� �犨� 矄  v = b x ᨨ �ᨨ矄�� x㜠 �矄ᔴᆠ盐 矄 ᨨ  �ᆠ�鼀t㦨 t 矄矄盐鼀   �ᆠ�矄ᨨ��� 㦨㡰᲼㝐� ҈꾀҈黨ᔼᔼ桌 㡰

b t 

㡰

ᆠ㡰

b t







b t 

㡰

�

b t

㡰

ᆠ㡰



�鼀

꾀�ᆠ�矄鼀ᨨ� �矄犨 矄犨� ᨨᆠ�泐ᨨ �鼀⏌矄ᔼ

҈矄 ᨨᆠ�泐ᆠ  �矄ᨨ�鼀⏌矄 ᨨ 犨 矄 � ᆠᆠ�ᨨ �  �矄�鼀�矄⏌ ᲼҈黨㜠㝐├矄桌

㡰 ҈⏌Ö鼀⏌矄ᨨ犨 矄 ᨨ 㜠犨矄

�鼀

ᆠ㡰 ҈⏌  鼀⏌矄ᨨ犨 矄 ᨨ 㜠矄

ᨨᆠ�泐

ᨨ矄��ᨨ

㡰 

ᔼ ҈矄�ᆠ�ᨨ矄 ᨨ鼀ᨨ� Aᨨᨨ� B鼀ᨨ� ��

矄鼀�ᆠ�ᆠᨨ  �盐矄҈鼀 矄 ��盐㡰 鼀� �盐 ᨨ  �ᨨᆠ�泐 A ᲼҈黨黨黨和㜠㝐├矄桌

҈ m ⏌ s  ᨨ犨 矄 ᨨ 

10 Subjective Problems 

㡰 ҈鼀⏌矄

҈ m ⏌ s  ᨨ犨 矄 ᨨ 㜠犨矄 

�鼀

㡰 

MCQs with One or More than One Correct Answer

㡰 ᨨ

�矄 ᆠ

ᨨ矄��ᨨ

꾀�ᆠ鼀ᨨ矄� ᆠ�ᆠᨨ  �盐矄Rᔼ    �ᨨ ᨨ ᨨ盐�ᨨ �矄 �矄ᆠ鼀 �矄힘힘힘힘힘힘힘힘힘힘힘힘  �矄 ᆠ ᆠᨨ �矄힘힘힘힘힘힘힘힘 ᲼҈黨㜠㝐├矄桌 6

 꾀 � 矄ᨨ犨�   ᨨ矄  矄鼀 鼀ᨨ�ᨨ 졠 ᨨ  鼀 ᨨ矄�� ᆠᨨᆠ泐�ᆠ├�盐 ᲼㝐� ҈桌 ᨨᆠ�泐

Fill in the Blanks

4

MCQs with One Correct Answer

꾀 矄犨  ᨨᨨ犨� ���� � 矄ᨨ 矄� � 

㡰 鼀⏌矄

1.0m

ᔼ矄   �鼀 ��ᨨ  ᨨ ᨨ矄��ᨨ 矄 ᨨ犨 �   ��盐

ᆠ㡰 ҈鼀⏌矄

ᨨ矄 �  盐䁸᲼҈黨䰘黨桌 㡰 ᨨ B

WWW.JEEBOOKS.IN

EBD_8341 P-12

Physics

Topic-2 : Non-uniform Motion

҈

�

MCQs with One Correct Answer

ᨨᆠ�泐 v㡰 �鼀 t㡰� ᨨ ᨨ 泐� 矄��  � 鼀ᨨ�ᨨ �矄矄 ᨨ犨 �   ��盐 ᨨ� S�矄 矄ᆠᨨ 矄 ᨨ �矄 ᆠᆠᨨ 泐 ᨨ 泐� 矄�矄 ᲼㝐� �和 ᔼᔼ㡰桌 v 鼀⏌矄㡰    

A

B S

D

t � 矄㡰

҈    �  C

䰘 黨 鼀 㡰 ҈鼀 ᆠ㡰 ҈҈鼀 㡰 鼀   ҈ 꾀盐ᨨ 鼀矄矄� 矄 � ��矄 ᨨ ҈鼀矄 盐矄  ᨨ�矄矄 � �鼀盐 犨ᨨ  �ᆠ├ 矄矄ᆠ鼀 ᔼ  犨ᨨ 矄鼀 矄�矄 ᆠᨨ �맔҈ 矄 ᨨ  盐 鼀�� � ᨨ鼀 ᨨ 矄� ᨨ  犨 �矄ᆠᨨ矄ᨨ ᲼㝐� ҈꾀҈黨 ᔼᔼ㡰桌 㡰 ҈鼀矄҈ 㡰 䰘鼀矄҈ ᆠ㡰 鼀矄҈ 㡰 鼀矄҈

ᨨ矄��ᨨ ᨨ �ᆠ矄 盐 ᆠ�ᨨ ᨨ �鼀t�矄�� 泐 x t㡰㦨at졔btct 犨 ab cᆠᨨ 矄 矄␔   �ᆠ� 矄 ᨨᆠᆠ�ᨨ   �矄ᨨᆠ�泐犨� ᲼㝐� 黨꾀҈黨 ᔼᔼ㡰桌



㡰





b 㡰 a + c

b 㡰 a + c

㡰 䰘�鼀 �矄

㡰 ��鼀 ҈矄 ᆠ㡰 ҈҈�鼀 �矄

䰘

b b 㡰 a + c c 꾀�ᆠ矄矄 ᨨ鼀ᨨ��� 졠 ᨨ鼀矄 鼀ᨨ矄犨�  盐 � ᨨ鼀ᆠᆠ�ᨨ ᨨ � ᨨ矄��x㜠 �矄ᔼ  � 泐 ��盐矄 ᆠᨨᆠ泐矄 矄 鼀ᨨ�ᨨ ⼄盐��泐 a㦨ᆠᆠ�ᨨ v㦨ᨨᆠ�泐x㦨 �矄ᆠ鼀 t㦨�鼀㡰 ᲼㝐� 꾀҈黨 ᔼᔼ㡰桌



҈�

졠 



ᔴ  ҈ ҈�  �

�鼀�  矄㡰®



㡰





㡰 ᆠ㡰 㡰    ␔ �ᆠ  �  ᆠᨨ矄ᨨ 矄ᨨ   ᨨᆠ 鼀ᨨ� � 犨�   ᆠᨨ 矄  ��ᆠᆠ�ᨨ  ᨨ矄��ᨨᆠ�泐䁸 ᲼㝐� 졠 � 꾀�҈䰘桌

㡰

㡰

㡰

㡰 ᨨᆠ�泐

㡰 㡰 ᔴ㡰 ᆠ㡰 꾀㡰 㡰 ᔴ㡰

和ᆠᨨᨨ







ᔴ㡰



꾀鼀 � ᆠᨨᆠ�ᨨ 턼ᨨ 矄��  �� 犨泐�矄鼀ᨨ� � 犨� 矄  ᆠ� 矄ᨨᆠ ᨨ� �  �  �矄 ᆠ  ᨨ鼀 �� 犨泐 ᨨ� 㝐㡰矄矄 ᨨ犨 �   ��盐 和 ᨨ  ᆠ�   � �矄  ᨨ ᨨ   �� 犨泐 ␔ 矄 ᨨ盐   �矄 ᆠ 㝐矄ᨨ  �鼀├ ᨨ ᆠ �矄鼀� �鼀盐鼀䁸᲼㝐� 졠 � 꾀�҈�҈桌



꾀㡰

꾀 ᔴ 

�

㡰 ҈҈�鼀 ҈�矄

ᆠ㡰 a + 

ᔼ ᆠᆠᨨ 矄�� ᨨ ᆠ꾀├矄�鼀矄矄   ᆠ  � �矄  矄矄矄 � �矄 � �ᨨ� 犨� 矄 ἘvἘ鼀ᨨ  ᨨ ᆠᨨ  ᆠ矄矄 ᨨ鼀 矄    犨�  ᆠᨨ 矄  ᆠᆠ�ᨨ  ҈   矄ᆠ�泐   ἘvἘ �矄 ⼄盐 ᨨ ᲼㝐� 黨 ҈黨 ᔼᔼ㡰桌 ҈   㡰 㡰  ҈    ҈ +   ҈ +   ҈     ᆠ㡰 㡰 

ᨨᆠ�泐㜠�鼀� 矄ᨨ ᆠ 矄ᆠᨨᨨ矄 ᨨ犨

�    ��盐 �㡰   �  ᆠ 犨    �矄 ᆠ  泐 ᆠ  矄ᆠᨨᨨ� ҈�矄  ��㡰 �鼀  犨 �ᆠ    ᆠ 犨� ᆠᆠ  盐 犨�    矄ᆠᨨᨨ  矄ᆠ�泐 ᲼㝐� 졠 � 꾀�҈�҈桌

ᨨᆠ�泐 鼀矄҈㡰®

1

㡰 꾀㡰 㡰 꾀㡰 㡰 㡰

ᨨᆠ�泐

�鼀

�鼀

WWW.JEEBOOKS.IN

P-13

Motion in a Straight Line

ᆠ㡰



2 ᨨᆠ�泐

ᨨᆠ�泐

�矄 ᆠ

�矄 ᆠ

黨

 �矄 ᆠ 泐ᨨ 泐鼀ᨨ� �ᨨ �� �

�鼀t�矄ᨨᨨ�ᨨ ᨨt

ᆠᆠ�ᨨ 㜠�鼀 at㡰�  ᨨ 鼀ᨨ�ᨨ ᨨ   ᨨ 泐犨� ᲼㝐� 졠 � 㝐y҈҈桌

Integer Value Answer

҈ 꾀ᨨᆠ├�矄鼀ᨨ� �� ��泐 矄ᆠ犨� ᆠᨨ 矄  ᆠᆠ�ᨨ ᨨ 鼀⏌矄ᨨ �졔  �ᆠ�ᨨ  矄 ��盐㡰   � ᨨ ᆠ 鼀� 矄�  ᨨᆠ├�矄鼀A�矄  ᨨ犨  ᨨ鼀   ᨨ  ᆠ 鼀� 졔x �ᆠ�ᨨ

犨� 矄 ᨨ 鼀⏌矄�ᨨ ᨨᆠ├꾀 矄鼀 �鼀 ᨨ �矄 ᨨ犨 � x �ᆠ�ᨨ 犨� 矄 ᨨ 鼀⏌矄 ᨨ鼀�矄��  �ᨨ ᨨᆠ├ �鼀�

矄ᆠᨨ 矄犨   犨ᨨ矄 �ᆠ ᨨ �矄 ᲼꾀 ҈桌  鼀⏌矄 㦨鼀⏌矄

鼀⏌矄 a

a

㡰

鼀

㡰 3 t

t

a ᆠ㡰

a

Numeric Answer

҈ 矄 矄矄�鼀�  ᨨ�ᆠ�矄矄 ᨨ犨 �   ��盐  �矄 ᆠ  � 鼀㡰泐 �ᆠ 盐� �  �鼀� t㦨ᨨt㦨�矄犨�힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌



҈  u ҈  鼀矄 㡰  

t t ҈ ᨨᆠ�泐㜠 �矄ᆠ鼀 � ᨨ �ᆠ鼀ᨨ� � ᨨ �矄�� � �矄矄 ᨨ犨

᲼�和桌

҈    � �鼀 s㡰

鼀ᨨ矄矄盐�ᆠᆠ�ᨨ 㜠 �矄ᆠ鼀 � 犨� 

҈  �矄 ᆠ ᆠᨨ 泐�ᆠ� ᨨ  �鼀 矄�ᨨ  鼀ᨨ�ᨨ �矄犨�  �鼀t矄 x㦨 at졔 bt졔 cᔼ   ᆠᆠ�ᨨ ᨨ  �ᆠ  矄ᨨ x矄xn犨 n �矄 � � 盐ᨨ n�矄힘힘힘힘힘힘 ᲼㝐� 黨  ᔼ㡰桌 6

҈҈

㡰

㡰

ᆠ㡰



҈� 꾀�ᆠᨨ 鼀矄矄m鼀ᨨ矄ᨨ  x㜠 �矄矄 ᨨᨨ犨矄� 矄矄 ᨨ鼀矄t㦨 ᨨ鼀 ᨨ� x㦨 ᆠᨨ鼀矄ᨨ 矄t㦨҈ ᨨ� x㦨҈졠ᨨ  � ᨨ鼀�ᨨ �矄 �ᨨ盐�矄鼀ᨨ�ᨨ � 鼀 ��鼀矄 ҈㡰ᔼ a  ᨨ矄 � 矄  ᨨ盐矄ᆠᆠ�ᨨ ᨨ  �ᆠ    ᲼҈黨黨㜠㝐├矄桌 㡰 a ᆠ

ᨨ 鼀�  ᨨ矄�� ᨨ  t �    � 

 £ t £ ҈

꾀ᨨ 泐矄矄 ᨨ鼀矄�鼀t㦨 ᆠᆠ�ᨨ �鼀 �  �矄 矄 ᨨ犨  �    ��盐  鼀 �鼀盐鼀 ᨨᆠ�泐 �  泐 ᨨ 泐犨� ᲼和桌 㡰 ҈҈鼀⏌矄

꾀ᆠᆠ�ᨨ



鼀⏌矄 㡰 ҈

㡰 ��鼀⏌矄 ᆠ㡰 �鼀⏌矄 㡰 ��鼀⏌矄

MCQs with One or More than One Correct Answer

҈҈ �鼀 矄ᆠ㡰

㡰 aᆠ

ᨨ ᆠ  泐ᨨ� � �矄  ᆠ㡰 a| 鼀盐矄  ³  矄ᨨ鼀ᨨ� ᨨᨨ� 矄� �矄  㡰 a鼀盐矄ᆠ  �矄��  盐� � 鼀ᨨ�ᨨ 盐 ᨨᨨ  矄矄�ᨨ ᆠ 鼀 犨�  � ᨨ鼀�ᨨ ��  10 Subjective Problems ҈ 꾀ᆠᆠᆠ矄 ᨨ鼀矄ᆠᨨ 矄 a ᨨ矄ᨨ鼀 �鼀 犨 �ᆠ � ᆠ矄ᆠᨨ 矄 bᨨᆠᨨ鼀 ᨨ矄ᔼ  ᨨ�鼀矄�矄t矄ᆠᨨ 矄盐 ᲼҈黨䰘桌 �㡰 鼀 �鼀盐鼀ᨨᆠ�泐ᆠ   ��㡰  ᨨ �矄 ᆠ 

WWW.JEEBOOKS.IN

EBD_8341 P-14

Physics

Topic-3 : Relative Velocity in One Dimension 1 ҈







�

MCQs with One Correct Answer

� A � B盐

� �ᨨ ᆠ├矄�   ᨨᨨ矄� �ᆠ�ᨨ 矄犨� 矄 矄ᨨ ├鼀⏌ ᨨ盐 䰘├鼀⏌ ᨨ盐矄ᆠ�泐꾀矄ᨨ �矄犨├� �� � A�   �ᆠ�ᨨ ᨨᨨ矄�ᨨ�矄鼀ᨨ�ᨨ 犨� 矄 ᨨ ҈├鼀⏌ ᨨ盐和  � 鼀矄҈㡰ᨨ  �矄矄ᨨ 矄ᨨ矄  ᨨ鼀�

B犨�ᆠᨨ矄ᨨ ├  �矄 ᆠ犨  ᆠ├矄矄

����㡰 [Main 2 Sep. 2020 (I)] ҈ ҈ 㡰 黨�鼀矄  㡰 �鼀矄  ᆠ㡰 ҈�鼀矄҈⼄ 㡰 �鼀矄҈ 꾀矄ᨨ 矄 � �ᨨ  ᨨ �ᨨ盐  矄 矄ᨨ盐 ᨨ ᨨ ᆠᨨ鼀� � ᨨ鼀 ᨨ   �º犨� �ᨨ盐 盐  � 矄 ᨨ �� �ᆠ泐 ᨨ �矄ᨨ矄��ᨨ ᔼ v�矄 矄 ᨨ 矄ᨨ盐 矄 ᨨ    �矄 ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌



v v  㡰 v 㡰 ᆠ㡰 v 㡰    꾀ᆠ�矄矄 � �鼀 � 盐矄犨 �ᆠ �矄矄ᨨ矄

犨ᨨ矄鼀ᨨ� � 矄鼀� 矄 盐犨�  � 㜠   ᨨ犨 ᆠᆠ�ᨨ 矄 盐矄 矄ᆠᆠ�ᨨ 鼀⏌矄   ᆠ 矄ᆠᆠ�ᨨ 鼀⏌矄 ᆠ犨�ᆠᆠ 盐 犨�  盐矄 �鼀ᨨ  ᲼㝐� 졠 � 꾀�黨҈䰘桌 㡰 ҈҈ 矄 㡰 ҈ 矄 ᆠ㡰 ҈  矄 㡰 ҈�矄 꾀矄ᨨ ᆠ�鼀矄盐矄 矄ᆠᨨ� 矄ᔼ 矄 � � ᨨ  矄鼀盐矄ᆠᨨ盐

� �犨� ᆠᨨ 矄 ᨨᆠ�泐 ├矄矄ᨨ犨鼀盐ᆠ �鼀�矄├ 泐 矄ᨨ ᨨ 犨├盐 鼀ᨨ� �矄ᆠᨨ䁸 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 䰘矄 㡰 䰘矄 ᆠ㡰 矄 㡰 �矄



2 Integer Value Answer 꾀� 矄A B 泐� �犨� ᆠᨨ 矄 ᨨᆠ�泐�   矄鼀�ᆠ  �矄   犨� 矄ᆠᨨ   ᨨ� ᨨ 矄ᆠ�泐矄矄 ᨨ犨 �  ��盐 矄 ᨨ A�矄 ҈  鼀⏌矄꾀�鼀t㦨矄 ᨨ矄� A � 矄 B �矄 ᆠᨨ �鼀 ᨨ矄矄矄B鼀ᨨ� �犨� ᆠᨨ 矄 ᨨᆠ�泐 �ᆠ盐ᨨ � ᨨ 鼀ᨨ�ᨨ ᨨ Aᔼ t㦨t꾀盐矄矄ᆠ矄� � �泐Bt� 矄ᆠᨨ 矄 �矄 ᲼꾀 ҈桌 A

B





䰘

黨

4 Fill in the Blanks ᨨ盐矄ᨨ 矄KLMN� ��泐  ᨨ盐ᆠᨨ 矄ᨨ 矄⼄盐ᨨ 矄� d쟼ᆠ 矄ᨨ  ᨨ犨鼀ᨨ矄犨� 盐 � ᨨ鼀 矄 v� 矄盐ᆠ 犨泐 ⧤犨泐矄鼀ᨨ矄 �ᆠ泐ᨨ犨 矄 L L �ᆠ泐ᨨ犨 矄 M M �ᆠ泐ᨨ犨 矄N   N �ᆠ泐ᨨ犨 矄K  ᨨ盐矄ᨨ 矄犨�鼀�鼀  ᲼҈黨㜠㝐├矄桌 5 True / False

犨ᨨ�  �ᆠ� 矄鼀ᨨ� �ᨨ �矄ᨨ � ⼄盐ᨨ ᨨ   � ᨨᨨ矄� �ᆠ�ᨨ 矄犨�  矄鼀矄 

泐犨�  矄鼀矄矄盐ᨨ  �矄 ᲼҈黨�㜠㝐├矄桌 9 Assertion and Reason Type Questions 和T꾀TE㝐ENT㜠҈ ᨨ ᨨ矄ᨨᨨ├� �ᨨ盐 ᨨ盐�   犨� ᨨ犨ᨨ  矄鼀ᨨ� ��   泐ᨨᆠ矄 ᨨ鼀ᨨ�  ᨨᨨ矄� �ᆠ�ᨨ ᨨ � 犨 �  �矄 ᨨᆠ矄ᨨ矄�ᨨ 泐 和T꾀TE㝐ENT㜠ᔼ  ᨨ矄  ᨨᆠ鼀ᨨ� � r r ᨨᆠ��矄 v ҈   v  矄ᆠ�泐犨�   ᆠᨨ ᨨᨨ泐 鼀 ᨨᆠ�泐ᨨ  ᨨᆠ犨� 矄ᆠᨨ r r ᲼桌  ᨨ矄�矄 v   v ҈  㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 ҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐 10 Subjective Problems 졠  �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ矄矄盐鼀 ᨨ x㜠 y 矄鼀ᨨ泐A�矄鼀ᨨ� �ᨨ �矄�� �  ᨨ y㜠 �矄 矄 ��盐㡰犨� ᆠᨨ 矄 ᨨᆠ�泐 ᨨ   - ҈㡰 鼀⏌矄꾀 꾀�ᆠ盐� 矄 犨   � OA 鼀├矄  �ᨨ � 犨�  x㜠 �矄�矄 ᨨ犨

ᨨ � 矄盐 ᆠ ᨨ鼀 ᨨ��� Oᔼ矄ᨨᆠ�泐鼀├矄

 �f犨�  x㜠 �矄 � �矄 ᨨ泐 泐 㡰 鼀ᨨ�ᨨ  ᨨ   �矄 꾀 ᨨ矄  ᨨ鼀  鼀ᨨ   ᨨ泐 ᔴᆠ盐    � q 鼀  泐   ᨨᆠ�泐ᆠᨨᨨ   犨�  x㜠 �矄�  �矄 鼀 � 㡰 �  矄 ᨨ   졠 犨� 矄ᆠᨨ 矄盐 ᆠ � f㦨q⏌ ᲼㜠�㝐├矄桌

Topic-4 : Motion Under Gravity 1 ҈

MCQs with One Correct Answer

꾀 �ᆠᨨ�矄矄 ᨨ鼀矄ᨨ  �ᨨ盐 �ᆠ泐盐㜠 犨 矄犨�  ᆠᨨ 矄  ᆠᆠ�ᨨ  g 꾀  ᨨᨨ ᆠ├ �矄

ᨨ  ᨨ鼀  �ᆠᨨ犨  ��矄 �� h  �鼀├ 泐 ᆠ├ᨨᆠ  �ᨨ盐 �矄ᆠᨨ矄ᨨ᲼g �矄 ᆠᆠ�ᨨ  盐ᨨ��泐桌 ᲼㝐� �和 ᔼ㡰桌

WWW.JEEBOOKS.IN

P-15

Motion in a Straight Line

(a) t =

2.

2 æhö ç ÷ 3 ègø

(The figures are schematic and not drawn to scale)

h g

(b) t = 1.8

240

æhö 2h (c) t = 3.4 ç ÷ (d) t = 3g ègø A Tennis ball is released from a height h and after freely falling on a wooden floor it rebounds and reaches height

(a)

h . The velocity versus height of the ball during its motion 2

(c)

may be represented graphically by : (graph are drawn schematically and on not to scale) [Main 4 Sep. 2020 (I)] h/2

h(v)

(b)

(c)

h h/2

h(v)

(d)

h h/2

h(v)

A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time? [Main 2017]

3.

(b)

(a)

240

8 (y2 – y1) m

12

t(s)

(d) t® 8

6.

v

v

t(s)

12

(y2 – y1 ) m

t(s)

12

12

t(s)

From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is: [Main 2014] (a) 2gH = n2u2 (b) gH = (n – 2)2 u2 d (c) 2gH = nu2 (n – 2) (d) gH = (n – 2)u2 A ball is dropped vertically from a height d above the ground. It hits the ground and bounces up vertically to a height d/2. Neglecting subsequent motion and air resistance, its velocity v varies with the height h above the ground as [2000S]

5.

h(v)

h

h

(y2 – y1 ) m

(b)

240

h/2

(a)

240

8

v

v

(y2 – y1) m

(a)

(b)

(c)

(d)

3 Numeric Answer A ball is dropped from the top of a 100 m high tower on a

7.

1 s before hitting the ground, it covers a 2 distance of 19 m. Acceleration due to gravity (in ms–2) near the surface on that planet is _______. [Main 8 Jan. 2020 (II)]

planet. In the last

(c)

(d)

Two stones are thrown up simultaneously from the edge of a cliff 240 m high with initial speed of 10 m/s and 40 m/s respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first ? (Assume stones do not rebound after hitting the ground and neglect air resistance, take g = 10 m/ s2) [Main 2015]

4.

5 True / False Two balls of different masses are thrown vertically upwards with the same speed. They pass through the point of projection in their downward motion with the same speed (Neglect air resistance). [1983 - 2 Marks]

8.

Answer Key Topic-1 : Distance, Displacement & Uniform Motion 4. (2R, pR) 5. (b) Topic-2 : Non-uniform Motion 3. (b) 4. (d) 5. (c) 6. (c) 7. (a) 13. (20) 14. (3) 15. (a, c, d) Topic-3 : Relative Velocity in one Dimension

1.

(b)

2. (b)

3. (b)

1. 11.

(a) (b)

2. (b) 12. (8)

1.

(a)

2. (d)

3. (c)

1.

(c)

2. (c)

3. (a)

8. (c)

9. (b)

10. (a)

ædö ç v ÷ 7. (False) 8. (b) è ø Topic-4 : Motion Under Gravity 4. (b) 5. (c) 6. (a) 7. (8.00) 8. (True) 4. (c)

5. (5)

6.

WWW.JEEBOOKS.IN

EBD_8341 P-16

Physics

3

Motion in a Plane

Topic-1 : Vectors MCQs with One Correct Answer uur uuur uur uuur  꾀҈ 㦨 꾀  㦨�  꾀҈ + 꾀  㦨� 盐ᨨ uur uuur uur uuur 꾀҈ + 꾀  · 꾀҈ - 꾀  �矄᲼㝐� 꾀�҈黨 ᔼᔼ㡰桌 㡰 ҈� 㡰 黨黨� ᆠ㡰 ҈҈� 㡰҈҈� ᔼ   ᆠ盐ᨨ 矄� � 矄 ᨨ犨 �    ��盐  ᆠᨨ ᨨ鼀 ᆠ  ᨨ� ᨨ   ᆠ꾀졠ᨨ ᆠ  ᨨ� ᨨ   ᆠ쟼 졠犨�᲼㝐� ҈ ҈黨 ᔼ㡰桌 1

҈

(



)(

)

� ҈  黨 㡰 ᆠ㡰 㡰 黨 黨 黨 ҈ r r r

ᆠᨨ矄  턼   矄 ᨨ犨 �   ��盐和 r  泐ᨨ� ᨨ  ᆠᨨ   �矄 ᆠ犨   r ᨨ� 矄 和�矄  � �ᨨ 鼀ᨨ �ᆠᨨ矄 r r r ᲼꾀 ҈䰘桌  턼   和 �矄

㡰 �

Ӹ 







r r r 㡰  和 = ҈ - 㡰 + 턼 r r r ᆠ㡰 和 = ҈ -  㡰 + 턼



(

)

(

)

( (

) )

҈ ҈ ˆ ˆ  � -k  kˆ - �ˆ 㡰   ҈ ҈  ˆ - kˆ  ˆ - �ˆ ᆠ㡰 㡰   ur ur

犨ᨨ ᆠᨨ矄 꾀 ur    ur    ⼄盐 鼀� �盐 矄  鼀� �盐  ᨨ  꾀 +   �矄 �  �鼀矄   鼀� �盐  ᨨ ur ur ur ur 꾀 -      � 犨  꾀      �矄 ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌

㡰

(

(

)

3

䰘





和 턼

= 턼-  턼 

r r r 㡰 和 =  - ҈㡰 + 턼 r r r 㡰 和 = ҈ - 㡰 +   턼

Numeric Answer ®



)

é - ҈ù é - ҈ù 㡰 ᆠᨨ矄 -҈ ê  ú 㡰 ᆠᨨ矄 -҈ ê ë + ҈úû ë + ҈û é  -҈ù é -҈ù ᆠ㡰 矄� -҈ ê  ú 㡰 矄� -҈ ê

+ ҈ ë + ҈úû ë û r r  꾀 = �ˆ + ˆ㡰     = �ˆ - ˆ㡰   鼀� �盐  ᨨ   r r r r r r r ᆠᨨ  ᆠᨨ ᔴ 矄盐ᆠ   꾀ᔴ = ᔴ = 꾀 �矄��

泐 ᲼㝐� 졠 � 꾀�҈҈桌

  





꾀 ᨨᆠ F = �$ +  $ + k$ 㡰 ᆠ矄ᨨ�  $� +  $ - k$ 㡰 鼀

  鼀� �盐 ᨨ ᨨ⼄盐ᨨ盐 ᨨ�  $� +  $ + k$ 㡰 鼀 犨� x 㜠鼀 盐ᨨ x�矄힘힘힘힘힘힘 ᲼㝐� 和� ᔼ㡰桌 r r r r r

矄盐鼀ᨨ 犨ᨨ ᨨᆠ矄 P   Q �矄 R 矄盐ᆠ    R  㦨  P   r r

 �q �  �矄㡰  矄盐 ᨨ  P   Q r 犨�鼀├犨�  Q �矄_______  ᲼㝐� 䰘 ᔼᔼ桌 r r r r

犨ᨨᆠᨨ矄 A   B   �  矄 A 㦨 a�ˆ   B 㦨 a ᆠᨨ矄 wt �ˆ 졔矄�  wt ˆ 㡰犨 a�矄ᆠᨨ 矄  w㦨p⏌ r r r r  s҈ᔼ   A + B =   A  B  �鼀t㦨t ᨨ  �矄�鼀  盐ᨨ t� secᨨnds�矄힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌

WWW.JEEBOOKS.IN

P-17

Motion in a Plane

Topic-2 : Motion in a Plane with Constant Acceleration 1 ҈

MCQs with One Correct Answer

꾀ᨨᨨ �矄鼀ᨨ� �盐� ��ᆠ泐ᨨᨨ� 꾀ᨨ

 �ᨨ盐 ␔  ��矄 �� h҈��矄 � � �矄 ᆠd ᨨ� 㡰 ᨨ鼀꾀 矄 ��盐㡰矄矄�  � �º犨� 矄ᆠᨨ �ᆠ␔   ᨨᨨ ᆠ�鼀矄盐  盐  �� h��矄矄   �º犨� 矄ᆠᨨ  �ᆠ�  ��鼀ᨨ矄 盐 泐 �矄 ᆠd ᨨ� ᔴ㡰    �� h�矄 ��  º㦨�䰘䰘㡰 ᲼㝐� 和� ᔼ㡰桌









�°

°

꾀   ᔴ 㡰 ҈d  㡰 䰘d ᆠ㡰 d 㡰 d 和� � ᨨ鼀 ᨨ��� �鼀t㦨犨� � ��ᨨᆠ�泐 � ˆ 鼀矄҈�ᆠ鼀ᨨ矄�  xy 犨� ᆠᨨ 矄  ᆠᆠ�ᨨ ᨨ  ҈�ˆ +  ˆ㡰 鼀矄꾀�鼀t�矄ᆠᨨᨨ � 矄  鼀y鼀㡰 盐矄ᨨ t y矄ᆠ�泐 [Main Sep.04, 2020 (I)] 㡰 矄 ҈鼀 㡰 矄 �鼀 ᆠ㡰 矄 鼀 㡰 �矄 �鼀 꾀�ᆠ矄矄 ᨨ鼀 ᨨ��� t㦨犨�  � �� ᨨᆠ�泐ᨨ  �ˆ 鼀⏌矄 鼀ᨨ矄�  x㜠y 犨�  ᆠᨨ 矄  ᆠᆠ�ᨨ   �ˆ +  ˆ㡰  鼀⏌ 矄   x㜠



ᆠᨨᨨ �  ᨨ    �ᆠ    � 矄  犨   �矄 y㜠 ᆠᨨᨨ � �矄鼀�矄鼀矄 盐ᨨ �矄 ᲼㝐� 黨  ᔼᔼ㡰桌 㡰  㡰 � ᆠ㡰  㡰  r 꾀�ᆠ鼀ᨨ矄矄盐ᆠ  �矄ᨨ矄��ᨨ ᆠᨨ r  t㡰㦨ᆠᨨ矄 w �ˆ 졔矄� w ˆ 犨 w�矄ᆠᨨ 矄  t�矄�鼀 

�

犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄盐 ᨨ ᨨᆠ�泐 r r v  t㡰 ᆠᆠ�ᨨ  a  t㡰ᨨ  �ᆠ ᲼㝐�   ᔼᔼ㡰桌 r r r 㡰 v �矄 �ᆠ盐ᨨ r   a �矄 �ᆠ 犨泐 ᨨ鼀  ᨨ���

r r r 㡰 v   a ᨨ  �ᆠ盐ᨨ r r r r ᆠ㡰 v   a ᨨ ᨨ r r r r 㡰 v �矄 �ᆠ盐ᨨ r   a �矄 �ᆠ ᨨ犨 矄  ᨨ���

 ᨨ矄��ᨨ  ᆠᨨ ᨨ   �ᆠ ᆠ  �矄 犨�  �鼀 r ᆠᆠᨨ � � ᨨ   �ᨨ  r 㡰 = ҈�   $� +  -    㡰 $

(

(

䰘

҈

␔ �矄 鼀� �盐 ᨨ  ᆠᆠ�ᨨ t㦨҈䁸 ᲼㝐� 黨꾀�҈黨 ᔼᔼ㡰桌 㡰  㡰 � ᆠ㡰 ҈ 㡰 � ˆ ˆ 鼀 㦨  �  + 꾀�ᆠ鼀ᨨ矄 ᨨ鼀 ᨨ�  ҈ 犨�  � ��ᨨᆠ�泐 ��ˆ +  ˆ 鼀矄 ᔼ�矄ᆠ 盐ᨨ

泐ᆠᨨ 矄  ᨨᆠ犨 �ᆠ ᨨ 盐ᆠ矄ᆠᨨ 矄 ᆠᆠ�ᨨ

�ˆ +  ˆ 鼀矄 - ␔ �矄  �矄 ᆠᨨ  �ᆠ ᨨ鼀 ᨨ��� �鼀矄䁸᲼㝐� ҈҈ ҈黨 ᔼᔼ㡰桌 㡰 ҈�鼀 㡰  鼀 ᆠ㡰 �鼀 㡰 ҈ 鼀 r 꾀�ᆠ�矄鼀ᨨ� �犨� ᨨᆠ�泐 v 㦨⧤ y �ˆ 졔x ˆ 㡰 犨 ⧤�矄ᆠᨨ 矄  � ⼄盐�ᨨ  ᨨ�矄 �矄 ᲼㝐� 黨 ҈黨 ᔼ㡰桌 㡰 y㦨x졔ᆠᨨ 矄  㡰 y㦨x졔ᆠᨨ 矄  ᆠ㡰 y㦨x졔ᆠᨨ 矄  㡰 xy㦨ᆠᨨ 矄  Numeric Answer

꾀�ᆠ�矄鼀ᨨ� �ᨨ � x㜠ax�矄犨� �矄ᆠᨨᨨ �  犨� �鼀�t�� 泐x t㡰㦨҈졔tt꾀 ᨨ �ᆠ �矄鼀ᨨ� �ᨨ � y㜠 �矄犨� �矄ᆠᨨᨨ � 矄 盐 ᆠ�ᨨ

ᨨ �鼀�� 泐y t㡰㦨�t꾀t㦨҈矄 矄 ᨨ   矄ᆠᨨ �ᆠ矄鼀矄盐 �   鼀ᨨ   �矄�ᆠ �矄�� 矄 v   v � 鼀⏌矄㡰�矄힘힘힘힘 ᲼㝐�   ᔼ㡰桌 6

黨

)

)

)

3 

(

MCQs with One or More than One Correct Answer

和� ��鼀t 㦨 ᨨ鼀 ᨨ��� 犨� 矄 ҈鼀矄҈ �ᆠ ᨨᨨ犨矄犨ᨨ㜠 �鼀 矄�ᨨ ᆠᨨ泐�  x㜠y   矄ᨨ   �矄 ᆠᨨᨨ � 矄    泐  

x    x   y ᆠᨨ鼀ᨨ  矄 ᨨ  �矄  ᆠᆠ�ᨨ   ᨨ 泐ax ay矄ᆠ�泐 

᲼꾀 桌 㡰 ax㦨҈鼀矄�鼀�矄 犨   �ᆠ�矄  ᨨ��� ay 㦨҈鼀矄 㡰 ax 㦨�鼀�矄ay 㦨҈鼀矄�鼀矄 ᆠ㡰 t 㦨 �ᆠ矄ᨨᆠ�泐ᨨ� 矄�  x㜠 �ᆠ�ᨨ

㡰 ax㦨�鼀�矄 t 㦨҈矄  �犨   �ᆠ矄ᨨᆠ�泐  x �矄�矄� ҈ ᆠᨨᨨ � 矄ᨨ �ᆠ鼀ᨨ� ��  ��

泐x t㡰㦨aᆠᨨ矄 㡰 y t㡰㦨b矄�  㡰犨 ab a㡰 pᨨ矄��ᆠᨨ 矄 矄ᨨ ᨨ� �鼀 矄�ᨨ 矄 

᲼҈黨黨黨和㜠㝐├矄桌 㡰   ᨨ  �ᆠ�矄 �矄 㡰   ᨨᆠ�泐   ᆠᆠ�ᨨ  ᨨ    �ᆠ 

ᨨ鼀ᨨᆠ ᨨ t㦨p⏌ p㡰 ᆠ㡰   ᆠᆠ�ᨨ  ᨨ   �ᆠ�矄 犨泐矄 �ᆠ ᨨ犨 矄 ᨨᆠ盐矄 㡰   �矄 ᆠ 泐 �ᆠ� �鼀�  t㦨ᨨt㦨p⏌ p㡰�矄a ⼄盐�ᨨ y =

WWW.JEEBOOKS.IN

EBD_8341 P-18

Physics

Topic-3 : Projectile Motion 1 1.

A particle of mass m is projected with a speed u from the p ground at an angle q = w.r.t. horizontal (x-axis). When 3 it has reached its maximum height, it collides completely inelastically with another particle of the same mass and velocity uiˆ. The horizontal distance covered by the combined mass before reaching the ground is: [Main 9 Jan. 2020 (II)] (a)

2.

3 3 u2 8 g

(b)

3 2 u2 4 g

u2 5 u2 2 2 (c) (d) 8 g g The trajectory of a projectile near the surface of the earth is given as y = 2x – 9x2. If it were launched at an angle q0 with speed v0 then (g = 10 ms–2): [Main 12 April 2019 (I)] 5 1 (a) q0 = sin –1 and v0 = ms–1 3 5 3 æ 2 ö ms–1 (b) q0 = cos–1 ç ÷ and v0 = 5 è 5ø

3.

4.

5.

9 æ 1 ö (c) q0 = cos–1 ç ÷ and v0 = ms–1 3 è 5ø 3 æ 2 ö (d) q0 = sin –1 ç ÷ and v0 = ms–1 5 è 5ø A shell is fired from a fixed artillery gun with an initial speed u such that it hits the target on the ground at a distance R from it. If t1 and t2 are the values of the time taken by it to hit the target in two possible ways, the product t1t2 is : [Main 12 April 2019 (I)] (a) R/4g (b) R/g (c) R/2g (d) 2R/g Two particles are projected from the same point with the same speed u such that they have the same range R, but different maximum heights, h1 and h2. Which of the following is correct ? [Main 12 April 2019 (II)] (a) R2 = 4 h1h2 (b) R2 =16 h1h2 (c) R2 = 2 h1h2 (d) R2 = h1h2 A plane is inclined at an angle a = 30o with respect to the horizontal. A particle is projected with a speed u = 2 ms–1, from the base of the plane, as shown in figure. The distance from the base, at which the particle hits the plane is close to: (Take g=10 ms–2) [Main 10 April 2019 (II)]

(a) 20 cm (b) 18 cm

(c) 26 cm

A body is projected at t = 0 with a velocity 10 ms–1 at an angle of 60° with the horizontal. The radius of curvature of its trajectory at t = 1s is R. Neglecting air resistance and taking acceleration due to gravity g = 10 ms–2, the value of R is: [Main 11 Jan. 2019 (I)] (a) 10.3 m (b) 2.8 m (c) 2.5 m (d) 5.1 m 7. Two guns A and B can fire bullets at speeds 1 km/s and 2 km/s respectively. From a point on a horizontal ground, they are fired in all possible directions. The ratio of maximum areas covered by the bullets fired by the two guns, on the ground is: [Main 10 Jan. 2019 (I)] (a) 1 : 16 (b) 1 : 2 (c) 1 : 4 (d) 1 : 8 8. The position of a projectile launched from the origin at r t = 0 is given by r = 40iˆ + 50 ˆj m at t = 2s. If the projectile was launched at an angle q from the horizontal, then q is (take g = 10 ms–2) [Main Online April 9, 2014] 2 -1 -1 4 -1 3 -1 7 (a) tan (c) tan (d) tan (b) tan 3 5 2 4 9. A projectile is given an initial velocity of (iˆ + 2 ˆj ) m/s, where iˆ is along the ground and ˆj is along the vertical. If g = 10 m/s2 , the equation of its trajectory is [Main 2013] (a) y = x - 5 x 2 (b) y = 2 x - 5 x 2 (c) 4 y = 2 x - 5 x 2 (d) 4 y = 2 x - 25 x 2 10. A ball projected from ground at an angle of 45° just clears a wall in front. If point of projection is 4 m from the foot of wall and ball strikes the ground at a distance of 6 m on the other side of the wall, the height of the wall is : [Main Online April 22, 2013] (a) 4.4 m (b) 2.4 m (c) 3.6 m (d) 1.6 m 6.

MCQs with One Correct Answer

(d) 14 cm

(

2

)

Integer Value Answer

11. A ball is thrown from ground at angle q with horizontal and with an initial speed u0. For the resulting projectile motion, the magnitude of average velocity of the ball up to the point when it hits the ground for the first time is V1. After hitting the ground, the ball rebounds at the same angle q but with a reduced speed of u0/a. Its motion continues for a long time as shown in figure. If the magnitude of average velocity of the ball for entire duration of motion is 0.8 V1, the value of a is ____ [Adv. 2019]

12. A train is moving along a straight line with a constant acceleration ‘a’. A boy standing in the train throws a ball forward with a speed of 10 m/s, at an angle of 60° to the horizontal. The boy has to move forward by 1.15 m inside the train to catch the ball back at the initial height. The acceleration of the train, in m/s2, is [Adv. 2011]

WWW.JEEBOOKS.IN

P-19

Motion in a Plane

5 ҈

True / False

꾀ᨨᆠ� �  ᨨ鼀 �ᨨ盐  ᨨᨨ犨矄ᨨ�ᆠ 

矄 ᨨ  ᨨᆠ��矄鼀� �鼀盐鼀 ᨨᨨ �矄   ᲼҈黨㜠㝐├矄桌 10 Subjective Problems

҈

꾀 ᨨᆠA�矄├ �   ᨨ� x㦨鼀 y㦨҈�鼀 ᨨ  ├P�矄 ᨨ �ᨨ盐 꾀�鼀t㦨   ├ 矄矄鼀ᨨ� � ᨨ �   졔 x �ᆠ�ᨨ  犨�  

ᆠᆠ�ᨨ  ҈� 鼀⏌矄 꾀   矄鼀 � 矄   矄ᨨ  �矄 r ᨨᆠ  ᨨ鼀 ᨨ��� 犨� ᨨᆠ�泐 u 矄矄 ᨨ犨 꾀 꾀 矄�ᨨ 泐矄ᨨ ᨨ  �ᨨ盐 ᨨ矄矄 矄ᨨ  �� �  ᨨᆠ 盐� ��矄 ᨨ犨 犨 鼀ᨨ�ᨨ   �ᨨ � ᨨ  ᨨ� ᨨ 꾀 鼀ᨨ�ᨨ 矄�  XY  r �  u   �鼀 犨 �ᆠ  矄ᨨ  �矄 ᨨᆠ

├g㦨҈鼀⏌矄 ᲼㜠҈㝐├矄桌

҈�

꾀� 泐ᨨ �矄矄� � �犨� ᨨ盐 �ᆠ�ᨨ  ᨨ犨 矄鼀ᨨᨨ  ᨨ � ᆠ� �ᨨ q ᨨ鼀ᨨ� Pᨨ  ᨨᨨ鼀ᨨ   ᨨ �ᆠ�矄ᨨᆠ � 矄�  ᨨ  � ��矄 ᨨ  �ᆠ犨� 矄ᆠᨨ ᨨ �矄u   �ᆠ�ᨨ

ᨨ ᨨᆠ�ᨨ 鼀├矄  �a犨�  ᨨᨨ鼀矄矄 ᨨ犨

�  ��盐 ᲼҈黨黨㜠㝐├矄桌

a 

҈ 犨ᨨ�盐 矄矄�盐 ᨨ  ᨨᨨ  �ᨨ  �� ҈鼀 � ᨨ 矄 ᨨᆠ  犨�   矄鼀矄  �  鼀 矄҈  矄ᨨ鼀 � ᨨ �鼀졠 �盐  �矄 ᨨ� ᨨ 泐 ᨨ  �矄 盐犨 矄  �ᨨ  犨�   ᨨ� ᨨ  矄 ᨨ矄 ᆠᨨ� � �ᨨ� P �  �㡰 �鼀㜠� 犨

  �� �矄  ��㡰 ᆠᨨᨨ � 矄ᨨ  ᨨ� P ├ᨨ���

ᨨ  ᆠᨨᨨ � 矄泐矄鼀  ᨨᨨᨨ   ��� ᨨ犨  鼀盐  ᆠᨨ�矄� x㜠y  ᲼҈黨黨㜠�㝐├矄桌 ҈䰘 犨ᨨᨨ犨矄AB CD矄�盐  �矄 ᆠ 矄 矄 ᨨ犨 �  ��盐 AB�矄鼀 ��  CD�矄鼀 ��  ᨨ鼀 �ᨨ盐 꾀

ᨨᆠᨨ 鼀矄矄鼀�矄 ᨨ犨  ᨨ鼀 ᨨᨨ AB ᨨ� ᨨ 泐 犨� ᨨᆠ�泐ᨨ ҈鼀⏌矄ᨨ犨 矄CD ᲼҈黨黨㜠㝐├矄桌 和�鼀盐 ᨨ盐矄泐 ᨨ ᨨᆠᨨ 鼀矄矄鼀�矄 ᨨ犨  ᨨ鼀  ᨨᨨ CD  �ᨨ  ᨨ  ᨨ� ᨨ ᨨ犨 矄 AB犨�  矄鼀鼀� �盐 ᨨ � ��ᨨᆠ�泐矄 ᨨ   �矄ᨨᆠ 犨ᨨᨨᆠ矄鼀ᨨ�  矄鼀�ᆠ  ᆠᨨ� � 鼀� 㜠� 矄�ᆠ├ᨨᆠ ᨨ 

�㡰 ᔴᆠ盐  �矄 ᆠ�d犨  ᨨ犨矄  ��㡰 �  ᨨ矄��ᨨ 犨  ᨨᆠ矄 � �ᨨ盐  ҈ �ᆠ矄P Qᨨ 鼀矄矄�鼀 �鼀矄ᆠ�泐 矄�鼀盐 ᨨ盐矄泐 ᨨᆠ  ᨨ鼀 ᨨ� 矄 A   B ᨨ    �ᨨ盐  � ��ᨨᆠ��矄ᨨ P Q鼀├�  ҈�  �矄矄ᆠ�泐犨�   ᨨ� ᨨ AB矄矄 ᨨ犨 �

  ��盐쟼ᆠ �ᆠ 矄 � ��矄 ᨨ 黨鼀⏌矄  矄�ᨨ AB�矄�鼀 ᲼҈黨㜠㝐├矄桌



q

㡰 �   �矄 ᆠᨨ � ᨨᨨ鼀ᨨ  ᨨ 犨

 ᨨ� ᨨ ᨨᆠ�ᨨ P  ᨨ� Q犨   �ᆠ 矄 꾀矄矄盐鼀  �ᆠ ᨨ矄 ᨨ �  泐ᨨ 矄盐 ᆠᨨ  ᨨ �ᆠ�矄�矄 ᆠ㡰 㡰 ᔼ   ᨨ� ᨨ  �矄ᆠ鼀 ᨨ  �ᆠ矄矄

泐 ᨨ矄ᨨ  �ᨨ盐 �矄 ᨨ �  矄 ᨨ  ᨨ 犨� 矄ᆠᨨ �ᨨ盐  � 矄  犨  �ᆠ犨矄ᨨᆠ 

ᨨ �ᆠ�  矄鼀�ᆠ  盐 �ᨨ ᆠᨨ�矄�ᨨ 꾀  ᆠᨨ�矄�ᨨ Pᆠ矄�矄 鼀�   ᨨ矄��ᨨ ᨨ Q犨  � �矄 �ᨨ盐 ᨨ犨鼀盐ᆠ �鼀   ᆠᨨ�矄�ᨨ  ᨨ矄 �ᆠQ├ᨨᆠ   �ᨨ盐 䁸 ├g㦨黨鼀⏌矄

Topic 4 : Relative Velocity in Two Dimensions & Uniform Circular Motion 1 ҈

MCQs with One Correct Answer

꾀ᆠᨨᆠ├ 矄ᆠᨨ � 盐ᨨ盐矄泐鼀ᨨ� �矄ᆠᨨ Ἐ矄  ᨨ ҈ 鼀 �  �ᆠᆠ�ᨨ ᨨ  �ᨨ   

� 盐 �矄ᨨ 鼀矄㡰�矄ᨨ  ᨨ ᨨ  ᲼㝐� 和 ᔼ㡰桌 㡰 ҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈҈

WWW.JEEBOOKS.IN

EBD_8341 P-20

Physics

When a car sit at rest, its driver sees raindrops falling on it vertically. When driving the car with speed v, he sees that raindrops are coming at an angle 60º from the horizontal. On furter increasing the speed of the car to (1 + b)v, this angle changes to 45º. The value of b is close to: [Main Sep. 06, 2020 (II)] (a) 0.50 (b) 0.41 (c) 0.37 (d) 0.73 The stream of a river is flowing with a speed of 2 km/h. A swimmer can swim at a speed of 4 km/h. What should be the direction of the swimmer with respect to the flow of the river to cross the river straight? [Main 9 April 2019 (I)] (a) 90° (b) 150° (c) 120° (d) 60° Ship A is sailing towards north-east with velocity km/hr where points east and , north. Ship B is at a distance of 80 km east and 150 km north of Ship A and is sailing towards west at 10 km/hr. A will be at minimum distance from B in: [Main 8 April 2019 (I)] (a) 4.2 hrs.(b) 2.6 hrs. (c) 3.2 hrs. (d)2.2 hrs. Two particles A, B are moving on two concentric circles of radii R1 and R2 with equal angular speed w. At t = 0, their positions and direction of motion are shown in the

2.

3.

4.

5.

p ö æ figure : ç t = 2w ÷ø è

6.

7.

a

(c)

(d)

r r A boat which has a speed of 5 km/hr in still water crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of the river water in km/hr is [1988 - 1 Mark]

(a) 1

X

9.

B

® ® The relative velocity vA - vB is given by: (a) w(R1 + R2) iˆ (b) –w(R1 + R2) iˆ (c) w(R2 – R1) iˆ (d) w(R1 – R2) iˆ

r

a

A

R2

(b) r

8.

R1

a

a

(a)

[Main 12 Jan. 2019 (II)] Y

A particle is moving along a circular path with a constant speed of 10 ms–1. What is the magnitude of the change in velocity of the particle, when it moves through an angle of 60° around the centre of the circle? [Main Online April 10, 2015] (a) 10 3m/s (b) zero (d) 10 m/s (c) 10 2m/s If a body moving in circular path maintains constant speed of 10 ms–1, then which of the following correctly describes relation between acceleration and radius? [Main Online April 10, 2015]

(b) 3

(c) 4

(d) 41 A river is flowing from west to east at a speed of 5 metres per minute. A man on the south bank of the river, capable of swimming at 10 metres per minute in still water, wants to swim across the river in the shortest time. He should swim in a direction [1983 - 1 Mark] (a) due north (b) 30° east of north (c) 30° west of north (d) 60° east of north

Answer Key Topic-1 : Vectors 1.

(d)

2. (c)

3. (a)

4. (a)

5. (a)

6. (195)

7. (90)

8. (2.00)

Topic-2 : Motion in a Plane with Constant Acceleration 1. 10.

(d) 2. (a) (a, b, c)

3. (c)

4. (d)

5. (d)

6. (b)

7. (c)

8. (580)

9. (a, b, c, d)

7. (a)

8. (c)

9. (b)

Topic-3 : Projectile Motion 1. 11.

(a) 2. (c) (4.00) 12. (5)

3. (d) 13. (True)

4. (b)

5. (a)

6. (b)

10. (b)

Topic-4 : Relative Velocity in two Dimensions & Uniform Circular Motion 1.

(a)

2. (d)

3. (c)

4. (b)

5. (c)

6. (d)

7. (c)

8. (b)

9. (a)

WWW.JEEBOOKS.IN

P-21

Laws of Motion

Laws of Motion

4

Topic-1 : Ist, IInd & IIIrd Laws of Motion MCQs with One Correct Answer

1 ҈



꾀�ᆠ鼀ᨨ� ��  xy  � ᆠ矄ᨨᆠ�泐 r    ᨨᆠ F = k v y �$ + v x $ 㡰 犨 vx vyx r r  yᆠᨨ鼀ᨨ  矄ᨨ �矄ᨨᆠ�泐 v �  a �矄 ᆠᆠ�ᨨ

ᨨ  �ᆠ  犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 盐 ᨨ �ᆠ䁸 ᲼㝐� 和 ᔼᔼ㡰桌 r r 㡰 ⼄盐 �泐 v ´ a �矄ᆠᨨ 矄 � �鼀 r 㡰 F �矄矄 盐ᨨ鼀� �ᆠ � ᆠ㡰 ├� �ᆠ �泐ᨨ �ᆠ�矄ᆠᨨ 矄 � �鼀 r r 㡰 ⼄盐 �泐 v × a �矄ᆠᨨ 矄 � �鼀 꾀矄ᆠ矄 �� 矄ᆠ矄犨矄矄�ᨨ 泐�  泐 盐矄



꾀�矄 ᨨ犨 盐犨 犨�  � ��ᨨᆠ�泐 ᨨ鼀  矄盐 ᆠᨨ    鼀ᨨ�ᨨ ᨨ  �矄 ᆠ 泐 � ᨨᆠ⼄盐ᨨ鼀g 犨 鼀�矄鼀矄矄ᨨ  �矄 �矄� 矄  ᨨ盐矄ᨨᆠ�泐 g �矄ᆠᨨ 矄 㡰 �鼀├

泐 ᨨ�矄ᨨ�矄  � �矄 ᲼㝐� ҈꾀�҈黨ᔼ桌 æ g ö æ g ö ҈  -҈ ç  ÷ 矄� -҈ ç  㡰 ç ÷ ç �  ÷÷ g� g� è � ø è ø æ æ g ö ҈ g ö ҈  ÷ 㡰  -҈ ç  l ç҈ + ᆠ㡰 ç ÷ ç �  ÷÷ � ø g� è g � è ø 꾀�矄 ᨨ犨 �ᆠ泐盐 ├ 矄졔 㜠 �矄㡰 ᨨ鼀  �ᨨ盐  ᆠᨨᆠ鼀ᨨ鼀 盐鼀㜠 ��  㜠 㡰 ��鼀�矄

㡰

�

҈

᲼㝐� 黨꾀�҈黨ᔼ桌

dM t 㡰 = bv  t 㡰 dt 犨 v t㡰�矄�矄� 矄  ᨨ盐矄ᨨᆠ�泐 � 矄  ᨨ盐矄 ᆠᆠ�ᨨ ᨨ  矄��矄 ᲼㝐� 和� ᔼᔼ㡰桌

꾀矄矄盐�矄鼀矄矄� ᆠ矄矄

㡰 -bv t 㡰

㡰 -

bv M t 㡰

bv M t 㡰

㡰 -

bv   M t 㡰

ᆠ㡰 

꾀矄鼀ᨨ 鼀矄矄m�矄 ᨨ犨 盐犨 犨� ᨨᆠ�泐u ᨨ鼀 �ᨨ盐   � ᆠ矄矄�矄� ᨨᆠmkv 犨 v�矄�矄矄  鼀 �鼀盐鼀 �� �  泐  �矄 ᲼㝐� 和 ᔼᔼ㡰桌



㡰

㡰

ᆠ㡰



꾀�ᆠᨨ 鼀矄矄鼀�矄鼀ᨨ� �� 矄��  � 犨� 鼀ᨨ鼀 盐鼀和� ��鼀㦨 ᨨᆠ 㦨kᆠ矄�   矄鼀 �ᆠ�ᨨ ᨨ  鼀ᨨ� ��ᆠ 盐� ��鼀� 

矄ᨨ �矄鼀ᨨ鼀 盐鼀ᆠ  �矄 ᨨ鼀ᨨk�矄 ᆠᨨ 矄  盐ᨨ  �矄 ᲼㝐� ҈҈ ҈黨ᔼᔼ桌

㡰

ku  ҈  -҈ g k

㡰

҈ æ ku  ö  ҈ +  g ÷ø k çè

㡰

ᆠ㡰

ku  ҈  -҈ k g



҈ æ ku  ö  ҈ +  k çè g ÷ø

ᆠ㡰



k 

㡰

k 





 k p ├

WWW.JEEBOOKS.IN

EBD_8341 P-22

䰘

Physics

ABBC  CD矄�� � 矄�鼀 矄 鼀� �盐  ᨨ  ᨨ�鼀盐矄ᨨ   ᨨᆠᨨ  ᨨ 泐 ᨨ鼀t㦨m矄 ᨨt㦨҈m矄�矄矄 ᲼҈黨黨㜠㝐├矄桌 ᔴ 

꾀�ᆠᨨ 鼀矄矄鼀�矄ᆠ 盐ᨨ 泐 ᨨᆠ �� 泐



ᨨᆠ 㡰

 鼀��ᆠ犨 =   㡰ᔼ  �矄犨�矄ᨨ矄   �鼀 泐泐ᨨ矄� � 鼀ᨨ�ᨨ 矄� � ᨨ鼀矄  矄犨泐�矄ᨨᨨ᲼㝐� 졠 � 꾀�҈҈桌 㡰  㡰�� 矄

ᆠ㡰

҈ ᨨ� 㡰�� 矄  

㡰 ᨨ� 㡰�� 矄







㡰

҈ ᨨ� 㡰�� 矄 

 





꾀� 盐鼀 㡰ᨨ �  �ᆠ 矄ᆠ ᨨ 鼀矄矄鼀   �盐矄矄盐 �ᨨ  � 矄鼀ᨨᨨ ���  ᨨ� ᨨ  ᨨ ᨨ  �    >> 㡰    矄   ᨨ鼀 ᨨ矄��ᨨ 矄  ᨨ  �矄 鼀ᨨ盐   犨  犨ᨨ ��� 矄盐ᨨ矄 矄 ��盐㡰 ᔼ  ᨨ ᨨ   矄 �矄 ᨨ犨��

 矄     � ᨨᆠ  � ᆠ  泐 ᆠ 矄盐ᨨ    ᨨ � �鼀 �矄 矄矄盐鼀  ᆠᨨ�矄�ᨨ 矄  矄�ᆠ㡰᲼㝐� 졠 �  꾀�҈҈ ҈�桌



5













 ҈

�鼀 m 矄㡰

҈

҈ ҈

True / False

҈ 꾀ᨨᆠ├鼀ᨨ矄 ᨨ犨 泐盐矄 � � 矄盐ᨨ盐 � �� ᆠ├犨 矄 ᲼҈黨桌 6

MCQs with One or More than One Correct Answer

҈ 꾀  ᆠ 鼀ᆠ  ᨨ  ᲼҈黨㜠㝐├矄桌 㡰 �矄 � � 鼀泐  � ��ᨨ  㡰 ᆠ

ᨨ    � � 鼀 ᆠ盐矄     �矄 ᨨ� �ᨨ盐  矄盐  ᆠ㡰 �矄   � � 鼀 ᆠ盐矄 犨ᨨ 矄 犨矄  �ᆠ�  �矄 鼀 㡰 ᆠ

ᨨ    � � 鼀 ᆠ盐矄     �矄 ᨨ� �ᨨ盐�矄ᨨ犨  �矄



㡰

mv 2 2(L - nr)

㡰

mv 2 L - 2nr

9

mv 2 㡰 ᨨ L - nr 꾀ᨨ 泐ᨨ 鼀矄矄�├�盐   ᆠ�ᨨ ᨨ ᆠᨨ 矄  ᨨᆠ r r = ˆ� + ˆ  矄ᨨᆠ�泐㦨矄矄  = �ˆ - ˆ 鼀⏌矄

ᆠ㡰 黨



(



)

r r  㦨҈矄矄  = +ˆ 鼀 ⏌ 矄   ᨨᆠ �矄 ᲼㝐� 졠 � 꾀�҈҈҈桌

҈

㡰

( -ˆ + ˆ) 

㡰

æ  ˆ  ˆö ç - � + ÷  è � � ø

ᆠ㡰

( �ˆ - ˆ) 



æ ˆ  ˆö ç � - ÷  è� � ø

꾀�ᆠ鼀ᨨ矄�  X㜠Y 盐  � 盐 ᆠᨨ  ᨨᆠ 矄盐ᆠ    �矄 �  鼀ᨨ鼀 盐鼀 �矄 r p t 㡰 = A ᲼�ˆ ᆠᨨ矄 kt 㡰 - ˆ 矄� kt 㡰桌  犨  A   k  ᆠᨨ 矄 矄  �犨   ᨨᆠ  鼀ᨨ鼀 盐鼀 �矄 ᲼䰘桌 㡰  㡰  ᆠ㡰 � 㡰 黨 4

҈҈

Fill in the Blanks

Assertion and Reason Type Questions

҈ 和鼀 㜠҈ᔼ�矄矄�ᨨ盐 泐ᨨᆠ  ᨨ 盐矄 �ᨨ �ᨨ盐  和鼀 㜠 鼀� �盐 ᨨ  �ᆠ�ᨨ  ᨨᆠ  矄 ᨨ   盐ᨨ  犨ᨨ矄盐 ᆠ矄� ᆠᨨ ᆠ ᲼桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐 ҈� 和T꾀TE㝐ENT㜠҈꾀ᆠᨨ ᆠᨨ矄和ᨨ鼀 �矄 矄 ├ᨨ � ᆠᨨ ᆠ 盐 ᨨ盐犨� ᨨ盐 �矄ᨨ �� �  �矄 矄 ᨨ鼀  和T꾀TE㝐ENT㜠 ᨨ泐ᆠ�ᨨ  �矄 ⼄盐 ᨨᨨ矄�ᆠ�ᨨ  ᲼䰘桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和㜠 鼀 㜠�矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和㜠 鼀 㜠�矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐

鼀� �盐 ᨨ   ᨨᆠ �  犨ᨨ 矄㡰ᆠ� �ᨨ ᨨ 泐 �矄犨� �鼀t � 鼀�ᆠᨨ矄ᆠᨨ 矄㡰矄矄 ᨨ犨 �   ��

WWW.JEEBOOKS.IN

P-23

Laws of Motion

Topic-2 : Motion of Connected Bodies, Pulley & Equilibrium of Forces 

1 ҈







㡰 ҈

MCQs with One Correct Answer

㝐҈

꾀鼀矄矄ᨨ ҈├��矄矄盐矄  泐ᨨᨨ  � 鼀 ᨨ鼀  ᆠ�� �꾀 ᨨᆠ �矄�  ᨨ� ᨨ 泐 鼀� 㜠 ᨨ� ᨨ  ᨨ矄盐ᆠ   ᨨ  ᨨ  ᨨ鼀├矄   �ᨨ � 犨�  �ᆠ  F⼄盐矄 ├g 㦨҈鼀矄  ᨨᨨ鼀矄矄矄矄㡰 ᲼㝐� 䰘 ᔼᔼ桌 㡰 ҈ 㡰 黨 ᆠ㡰 䰘 㡰 䰘� 꾀  ᨨ �   盐� � � ᆠ  ᆠ泐 鼀 �鼀盐鼀 ᨨ  ҈ 矄ᨨ 矄犨�  �鼀矄矄ᨨ ᆠ 矄ᨨ � � ├� 鼀矄矄ᨨ  ᨨ�矄 �矄黨├� �鼀ᨨ矄 犨� ᆠᨨ 矄 矄 ᨨ 鼀⏌矄  �ᆠ�ᨨ  ᨨᆠᨨᨨ矄� �  鼀ᨨ�ᨨ �矄ᔼ  ᨨ�矄鼀ᨨ� �盐犨� �矄 盐 ᆠᆠ�泐   ᨨ犨 �  泐   鼀ᨨᨨ ᨨ   ᨨ g㦨҈鼀⏌矄㡰鼀盐矄矄 ᲼㝐� 䰘 ᔼᔼ桌 㡰 �␔ 㡰 ␔ ᆠ㡰 ␔ 㡰 ␔ 꾀鼀矄矄ᨨ ҈├��矄矄盐矄  �ᆠ泐泐ᨨ ᨨ鼀  ᨨᨨ ␔   ᨨ� ᨨ  ᨨᆠ�矄� ᨨ  ᨨ 矄ᨨ鼀ᨨ�  ᨨ �   �ᨨ �   ᨨᨨ ᨨ� ᔼ  矄盐矄  鼀矄矄�矄⼄盐���盐鼀  鼀� �盐 ᨨ   ᨨᆠ� �矄 �㦨҈鼀矄㡰 ᲼㝐� 黨 ҈黨ᔼᔼ桌 㡰  㡰 ҈ ᆠ㡰 䰘 㡰 ҈ 꾀鼀矄矄�鼀�矄矄盐ᨨ 泐鼀矄矄矄矄矄� �犨ᨨ盐 ᨨ盐 盐 � ᨨ鼀 ᨨᨨ犨ᆠ泐� ᨨ 鼀矄矄鼀  �盐矄 ᔼ   矄� � ᨨ矄 ᨨ矄�ᨨ  ᆠ泐� 犨� 犨 ᆠᆠ�ᨨ

犨� 鼀矄矄 ᨨ矄䁸 ᲼㝐� ҈桌 㡰

� 

㡰

� 

ᆠ㡰

�� 

㡰 黨 ᆠ㡰  㡰 ҈黨 

㝐

犨ᨨ�ᆠ矄ᨨ 鼀矄矄mᆠ �   矄ᨨ ��  矄� �ᨨ  � a 犨 ᨨ矄泐矄鼀�矄├ᨨ  �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ犨�  矄� �  �� 矄ᨨ ᆠ 鼀矄矄�矄 �矄 ᆠἘaἘ ᨨ鼀 ᆠ P 矄矄 ᨨ犨 �   ��盐㡰 ᨨ犨 鼀� 㜠ᨨ� ᨨ  矄� ��矄盐 �ᆠ泐盐犨 矄 犨� 矄鼀盐ᆠᨨ 矄  ᨨᆠF꾀矄矄盐 �ᆠ矄 鼀ᨨᨨ犨 矄ᆠ ᨨ ᨨ  矄盐 ᆠ 鼀� �盐  ᨨ  ᆠᆠ�ᨨ  犨     矄�ᨨ  犨   鼀 ᆠᨨ鼀矄x�矄 ᲼䰘桌 㡰

F a m a  㜠 x 

㡰

F x m a  㜠 x 

ᆠ㡰

F x m a



F a 㜠 x m x

F

m

a

䰘



m

P

a

矄� �犨  ᨨᆠ├矄ᨨ 鼀矄矄m 鼀�矄鼀矄矄矄矄 �   矄�  矄泐矄鼀 �矄 矄盐矄   泐  鼀矄矄矄矄 矄� �矄矄 ᨨ犨 ᔼ  矄� � �矄ᆠ盐 �  鼀� �盐 矄ᨨ ᆠᆠ�ᨨ 矄ᨨ 鼀矄矄m m �鼀鼀 �泐 ᆠ盐� �㡰 ᲼㜠㝐҈桌

m m

�

鼀 㡰 �

犨ᨨ ᨨᆠ├矄 ᨨ  鼀矄矄 㝐҈ 㦨  ├�  㝐 㦨 ҈ ├�  ᆠᨨ

ᆠ 泐  鼀 ᨨ ᨨ 鼀矄矄  ├�   矄泐矄鼀 �矄 盐 �ᆠ泐盐泐泐� � ᨨᆠᨨ 矄矄 ᨨ犨 

 矄�ᨨ  鼀� 㜠ᨨ� ᨨ  ᨨ �矄 ᲼㝐� 졠 � 꾀�҈桌

㡰 gg ᆠ㡰 

㡰 g

g � 



g 

g g   

꾀矄� �ᨨ  ����鼀矄矄�ᨨ� �ᨨᆠ鼀 盐泐ᨨ 鼀矄矄m 矄盐ᨨ矄ᨨᆠ├ᨨ 鼀矄矄M 矄矄 ᨨ犨 �   ��盐

 ᨨᆠᨨ  盐泐泐 ᆠ鼀�矄�� 泐᲼҈和桌

WWW.JEEBOOKS.IN

EBD_8341 P-24

Physics

M



黨

㡰

2 㝐�

㡰

2 鼀�

ᆠ㡰

( M + m) 2 + m 2 g



(M + m) + M g

m

2



M

a

2

a M

盐泐矄 矄� �矄矄 ᨨ犨 �   ��盐矄鼀ᨨᨨ   ᨨ  ���� 鼀矄矄 ᨨ   矄泐矄鼀 ᨨ鼀�  �

⼄盐���盐鼀  �q矄 ᨨ盐  ᲼҈和桌

M



㡰 ᨨ q

㡰 ᨨ

Öm 

ᆠ㡰 �ᨨ m

㡰 ᨨ 5 ҈

x ᨨ  矄� � 鼀� �盐   ᨨ ᆠᆠ�ᨨ ᨨ  ᨨᆠ├ᆠᨨ

ᆠ ᨨ 矄� � g �矄 ҈ Mg 㡰 x = k x ᆠ㡰 ␔  矄� �ᆠ �矄   矄�ᨨ ᨨ    ᨨ    �矄�鼀  矄 ᨨ  ᨨᆠ├ᆠᨨ

ᆠ ᨨ 

㡰 꾀   矄�ᨨ ᨨ 

m

True / False

盐泐 �鼀 矄ᨨ  ��矄 㡰  㡰�  �ᆠ

鼀矄矄ᨨ  ᨨ�矄 ����ᔼ  㡰 鼀矄矄m�矄 �  盐泐ᆠ � �鼀矄矄mᨨ ᨨ  ᨨ   ᨨᔼ  㡰m�矄�  盐泐盐� � ᨨ  ᨨ   ᨨ 犨�   ᆠᨨ 矄  ᨨ犨 犨  ᨨᆠ F 㦨  mg  ᆠᆠ�ᨨ ᨨ m�矄 矄鼀� ᨨ ᆠ矄矄 ᲼҈黨㜠㝐├矄桌

M �k 㡰 aa҈㦨a҈a ҈ ᔼ   �鼀 矄 ᨨ犨 �   ��  矄P Qᨨ  盐 矄ᆠ 矄� �鼀ᨨ ᨨ犨 犨 矄犨� 盐 � ᨨ鼀 矄 U盐泐矄A B �   ᲼҈黨㜠㝐├矄桌 㝐矄矄M鼀ᨨ矄盐犨 矄犨� 矄

矄� ��矄�

㡰 ᆠᨨ矄q

A

㡰 ⏌ᆠᨨ矄 q ᆠ㡰 ⏌ᆠᨨ矄q 㦨mg

m m

6 ҈҈

m 㡰

㡰

MCQs with One or More than One Correct Answer

꾀ᨨᆠ├ᨨ 鼀矄矄㝐�矄ᆠ  ᨨ鼀矄矄矄矄矄� �犨� 矄� �㜠ᆠᨨ 矄 k �矄ᨨᆠ├�矄ᆠᨨ

ᆠ ᨨ犨ᨨᨨ  ᨨᆠ├矄ᨨ 鼀矄矄矄㝐 㝐盐矄� �犨ᨨ鼀矄矄矄矄盐泐矄  矄� �矄 ᆠᆠ�ᨨ ᨨ  ᨨᆠ├矄a҈㜠a a矄矄 ᨨ犨 �   ��盐 矄泐矄鼀�矄矄  ᨨ鼀矄 犨�  矄� �� �矄盐 矄ᆠ  矄 鼀 �鼀盐鼀   矄�ᨨ  ᨨ   矄� � �矄 x ␔ �ᆠ  ᨨ    ᨨᨨ犨� � ᨨ�ᨨ 矄㡰 �矄⏌ ᆠᨨᆠ䁸 ᲼g �矄   ᆠᆠ�ᨨ  盐 ᨨ ��泐�ᆠ �ᆠ�ᨨ 桌 ᲼꾀 ҈黨桌

B

q q P

M

Q

㡰 ᆠᨨ矄q 10 Subjective Problems ҈ 犨ᨨᨨᆠ├矄ᨨ 鼀矄矄黨├� ҈黨├� 矄盐矄   ᨨ鼀  ���  矄盐ᨨ S 泐 犨ᨨ �   矄�犨�矄ᆠ ᨨ  � ҈鼀 矄 �� 盐犨� 矄 ����鼀矄矄   ᨨ犨犨� 矄盐 � ᨨ鼀鼀矄矄ᨨ  ├�⏌鼀 犨 ᨨ矄泐矄鼀ᨨ ᨨᆠ├矄犨�矄 矄盐ᨨ  盐犨 ᆠᆠ�ᨨ ᨨ  鼀⏌矄꾀ᆠᆠ�ᨨ  盐ᨨ��泐�矄黨鼀⏌ 矄  ᲼҈黨黨㜠㝐├矄桌 �㡰 �   矄�ᨨ  鼀� 㜠ᨨ� ᨨ   ᨨ犨犨� ��㡰 �   矄�ᨨ  鼀� 㜠ᨨ� ᨨ   盐犨�

S

黨├�

҈黨├�

WWW.JEEBOOKS.IN

P-25

Laws of Motion

Topic-3 : Friction

An insect is at the bottom of a hemispherical ditch of radius 1 m. It crawls up the ditch but starts slipping after it is at height h from the bottom. If the coefficient of friction between the ground and the insect is 0.75, then h is : (g = 10 ms–2) [Main Sep. 06, 2020 (I)]

Two masses m1 = 5 kg and m2 = 10 kg, connected by an inextensible string over a frictionless pulley, are moving as shown in the figure. The coefficient of friction of horizontal surface is 0.15. The minimum weight m that should be put on top of m2 to stop the motion is: [Main 2018] T m (a) 18.3 kg m2 m 2

(a) 0.20 m

(b) 27.3 kg

1 1.

2.

(b) 0.45 m

(c) 0.60 m (d) 0.80 m A block of mass 5 kg is (i) pushed in case (A) and (ii) pulled in case (B), by a force F=20 N, making an angle of 30 o with the horizontal, as shown in the figures. The coefficient of friction between the block and floor is m = 0.2. The difference between the accelerations of the block, in case (B) and case (A) will be : (g =10 ms–2) [Main 12 April 2019 (II)]

–2

3.

5.

MCQs with One Correct Answer

m1

(d) 10.3 kg 6.

7.

8. (a) 8 N (b) 16 N (c) 40 N (d) 12 N A block of mass 10 kg is kept on a rough inclined plane as shown in the figure. A force of 3 N is applied on the block. The coefficient of static friction between the plane and the block is 0.6. What should be the minimum value of force P, such that the block doesnot move downward? (take g = 10 ms–2) [Main 9 Jan. 2019 (I)]

1

(d)

2 - n2

1 1 - n2

A rocket is fired vertically from the earth with an acceleration of 2g, where g is the gravitational acceleration. On an inclined plane inside the rocket, making an angle q with the horizontal, a point object of mass m is kept. The minimum coefficient of friction mmin between the mass and the inclined surface such that the mass does not move is : [Main Online April 9, 2016] (a) tan2q (b) tanq (c) 3 tanq (d) 2 tan q Given in the figure are two blocks A and B of weight 20 N and 100 N, respectively. These are being pressed against a wall by a force F as shown. If the coefficient of friction between the blocks is 0.1 and between block B and the wall is 0.15, the frictional force applied by the wall on block B is: [Main 2015] F

A

B

P g

N

k 10

3

4.

m1g

A given object takes n times more time to slide down a 45° rough inclined plane as it takes to slide down a perfectly smooth 45° incline. The coefficient of kinetic friction between the object and the incline is : [Main Online April 15, 2018] 1 1 1- 2 (b) 1 - 2 (a) n n (c)

–2

(a) 0.4 ms (b) 3.2 ms (c) 0.8 ms–2 (d) 0 ms–2 Two blocks A and B masses mA=1 kg and mB = 3 kg are kept on the table as shown in figure. The coefficient of friction between A and B is 0.2 and between B and the surface of the table is also 0.2. The maximum force F that can be applied on B horizontally, so that the block A does not slide over the block B is : [Take g = 10 m/s2] [Main 10 April 2019 (II)]

T

(c) 43.3 kg

(a) 32 N

45°

(b) 18 N

(c) 23 N

(d)

25 N

(a) 120 N (c) 100 N

(b) 150 N (d) 80 N

WWW.JEEBOOKS.IN

EBD_8341 P-26

Physics

꾀ᨨᆠ├ᨨ 鼀矄矄鼀㦨҈├�矄矄ᨨ  ᨨ� ᨨ   ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  ᨨᆠ├  �矄 �␔   �泐盐ᨨ 鼀矄矄��鼀ᨨ� �犨� 矄 n �矄鼀  � � ᨨᆠ├鼀ᨨ矄 ᆠᨨ鼀矄ᨨ 矄ᨨ 鼀ᨨ� � �矄 ᆠᨨ 鼀ᨨ  ᔼ  泐 n � �ᨨᆠ犨ᨨᆠ⼄盐�矄   � � ᨨ ҈ ᨨ鼀 ��    �ᆠ� � �泐ᨨ矄矄矄 ├� �� 㦨҈鼀矄 盐ᨨ �矄ᆠᨨ矄ᨨ ᲼㝐� 졠 � 꾀�҈҈�桌 㡰 �├鼀 㡰 ├鼀 ᆠ㡰 ├鼀 㡰 ├鼀 ҈ 꾀ᨨᆠ├ᨨ 鼀矄矄鼀�矄ᆠ ᨨ 矄盐 ᆠ犨� �ᆠ 黨

  ᔼ  ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ

 �矄� 鼀 �鼀盐鼀 �� ᨨ �ᨨ盐 犨 �ᆠ   ᨨᆠ├ᆠ ᆠ 犨� ᨨ盐矄�� ��矄 ᲼㝐� ҈桌

ᆠᨨ矄矄矄ᆠ�ᨨ �� 泐 泐 =

҈  ҈ ҈ 鼀 鼀 鼀 鼀 㡰 ᆠ㡰 㡰     ᔴᨨ 矄� ᆠ泐� ᨨ 鼀矄矄㝐矄� �ᨨ ᨨ盐�  ᨨ� ᨨ  盐� �矄盐 ᨨ盐 ᨨ鼀盐 �犨� ᆠᆠ�ᨨ �  �ᆠ盐ᨨ  �矄ᨨ  ᆠ泐� ␔ �矄 �ᆠ�ᨨ

ᨨ� 䁸ᔼ�矄矄矄盐鼀   ᆠ泐�  ᨨ矄 ᨨ矄� ᲼㝐� 졠 � 꾀�҈黨҈桌

㡰 ҈҈

a

ᆠ㡰

㡰 졠

졠 t t ҈ 꾀ᨨ 泐矄矄 ᨨ鼀矄ᨨ ᨨ �� ᆠ�   ᨨ 矄ᨨ �  ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  ᨨ 泐    �矄矄m㦨x犨 x�矄 �矄 ᆠ ᨨ犨    ᨨ 泐犨� 鼀 �鼀盐鼀矄 ᨨg㦨҈鼀⏌矄㡰犨  x 㦨᲼㝐� 졠 � 꾀�҈桌 ᆠ㡰 ҈鼀 㡰 鼀 㡰 黨鼀 㡰 䰘鼀 ҈� 꾀ᨨᆠ├ᨨ 鼀矄矄鼀�矄ᨨ  � ᆠ�   ᨨ  �q  ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  ᨨᆠ├   �矄m   q>m ᨨᆠ├�矄  矄�ᨨ 泐泐泐� � ᨨᆠᨨ    �ᆠ�ᨨ ᨨ  ᨨᆠᨨ� � � 盐  �矄├ ᨨᨨ矄��꾀矄�矄�  ᨨ鼀 ҈㦨鼀� 矄� qm ᆠᨨ矄q㡰ᨨ㦨鼀� 矄� q졔m ᆠᨨ矄q㡰  �ᆠ�ᨨ  ᨨᆠf矄盐矄� 犨�ᨨᨨ├�├ ᲼҈桌 f

f

㡰

㡰

f

犨 

a



ᆠ㡰

f



 

�ᆠ�ᨨ

㝐 㝐 㡰   꾀ᨨᆠ├꾀ᨨ 鼀矄矄├��矄ᆠ ᨨ  ᨨ ᨨᆠ├ᨨ 鼀矄矄�├�  ᨨᆠ├矄矄ᨨ 矄鼀ᨨᨨ  ᨨ� ᨨ  ᔼ  鼀� �鼀盐鼀 ᨨᆠ ᆠ � ᨨ 꾀矄ᨨ  ᨨ  ᨨᆠ├矄鼀ᨨᨨ� �矄҈ 鼀 �鼀盐鼀 ᨨᆠ   ᆠ   �  ᨨ  ᨨ   ᨨᆠ├矄 ᨨ 鼀ᨨ ᲼㝐� 졠 � 꾀�黨҈桌 ᨨ� 犨� 㡰  㡰 � ᆠ㡰 䰘 㡰  꾀ᨨᆠ├�矄ᆠ ᨨ  ᨨ盐�  ᨨ� ᨨ  꾀�鼀    ᨨ� ᨨ  ᨨᆠ 㦨├ᆠ矄ᨨ  ᨨᆠ├犨  ├�矄ᨨ矄��ᆠᨨ 矄  ᆠᆠ�ᨨ 㜠�鼀� ᨨ  ᨨᆠ├�矄 ᲼㝐� 졠 � 꾀��҈桌

㡰 㝐� ҈

҈

㡰 㝐

ᆠ㡰

a

a

㡰

㡰



҈ 꾀ᨨᆠ├ᨨ 矄҈ᆠ鼀맔҈ᆠ鼀  �� ҈�ᆠ鼀�矄├ᨨ

 � ᆠ�    ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  鼀 �矄   � ᆠ� �ᨨ qᨨ  �矄� ᆠ�    ᨨ鼀  ᨨ� ᨨ  �矄� 盐泐� ᆠ矄  ᨨ鼀  

᲼黨桌 㡰 q㦨  ᨨᆠ├犨�矄矄� � � ᨨ犨    㡰  ᨨᆠ├犨�鼀� 矄ᨨ   盐ᨨᆠ�

q   �犨�ᨨ ᆠ㡰 q㦨  ᨨᆠ├犨�矄矄� � � ᨨ犨     ᆠᨨ � 盐ᨨ ᨨ矄ᨨ ��  �矄 㡰 q㦨  ᨨᆠ├犨�矄矄� � � ᨨ犨     ᨨ  盐 � ᆠ矄� �q�犨�ᨨᆠ� q. ҈䰘 ␔ �矄 鼀 �鼀盐鼀盐ᨨ   ᨨᆠF矄盐ᆠ    ᨨᆠ├矄 ᨨ犨 �   �鼀  ᨨ矄 ᨨ鼀ᨨ䁸᲼和桌 ҈ m=    鼀 = ├�

t



t

㡰  㡰 ҈ ᆠ㡰 ҈ 㡰 ҈� ҈ 꾀 � 矄ᆠᆠ犨矄盐 鼀�矄 �ᆠ矄盐 ᆠ泐矄ᨨ犨泐 矄 ��㡰 ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨   � 矄ᆠ   矄盐 ᆠ�矄҈⏌ᔼ  � ᨨ� � � ᆠ ᨨ   鼀�矄 �ᆠ矄盐 ᆠᨨ � 矄ᆠ鼀├矄  �a犨�  �ᆠ 鼀 �鼀盐鼀ᨨ矄矄�盐ᨨ a�矄�� 泐 ᲼҈和桌

WWW.JEEBOOKS.IN

P-27

Laws of Motion

 a

҈黨



㡰 ᆠᨨa㦨 㡰  a㦨 ᆠ㡰 矄ᆠa㦨 㡰 ᆠᨨ矄ᆠa㦨 꾀 ᨨᆠ├ᨨ  鼀矄矄҈ �矄   �� 矄  犨 泐� �  ᨨ� ᨨ  ᨨᆠᨨ �ᨨ  ᨨᆠ├ᔼ  ᆠᨨ �ᆠ� ᨨ �ᆠ�ᨨ 犨  ᨨᆠ├  犨�矄� 鼀� �盐  ᨨ   �ᆠ�ᨨ  ᨨᆠᆠ� �ᨨ  ᨨᆠ├�矄 ᲼҈黨黨㜠҈㝐├桌 㡰 � 㡰 黨 ᆠ㡰 黨 㡰 黨 꾀ᨨᆠ├ᨨ 鼀矄矄├�矄矄ᨨ ᨨ盐� � ᆠ�   鼀├� �   �ᨨ  犨�   ᨨ� ᨨ  ᆠᨨ �ᆠ� ᨨ 矄�ᆠ �ᆠ�ᨨ  犨    ᨨᆠ├      �矄䰘  �ᆠ�ᨨ  ᨨᆠᨨ  ᨨᆠ├�矄 ᲼҈黨桌 㡰 黨 㡰 䰘 ´ 黨 ´  ᆠ㡰 黨 ´  㡰 䰘맔黨 2

҈



꾀ᨨᆠ├�矄鼀ᨨ� �ᨨ  � ᆠ�   鼀├� �  � � 犨�   ᨨ� ᨨ   ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ �矄m

 ᨨᆠ⼄盐� ᨨ盐矄盐矄 �盐 � ᆠ�   �矄 �鼀矄  ᨨᆠ⼄盐� ᨨ盐矄 � ᨨ鼀矄� � � ᨨ犨  ᔼ 犨  � 㦨҈m  �矄 ᲼҈҈桌 꾀ᨨᆠ├ᨨ 鼀矄矄҈├��矄ᨨ  ᨨ� ᨨ 矄盐 ᆠ� 盐ᆠ├

ᆠᨨ �ᆠ� ᨨ 矄�ᆠ �ᆠ�ᨨ 犨  ᨨᆠ├   矄盐 ᆠ�矄ᔼ  ᆠᆠ�ᨨ ᨨ  盐ᆠ├�矄�鼀⏌矄  �ᆠ�ᨨ  ᨨᆠᆠ� �ᨨ  ᨨᆠ├�矄 犨ᨨ 矄 ᲼҈黨㜠㝐├矄桌 3



True / False

␔  矄ᨨ 犨├矄ᨨ ᨨ盐� 矄盐 ᆠ  �ᆠ�ᨨ  ᨨᆠ  泐 矄盐 ᆠᨨ  矄ᨨ �矄ᨨᨨ矄�ᨨ   �ᆠ�ᨨ ᨨ  �矄鼀ᨨ�ᨨ  ᲼҈黨҈㜠㝐├矄桌 6

�

Numeric Answer

꾀ᨨᆠ├矄矄鼀ᨨ� �盐 � ᆠ�   ᨨ � ᆠ� �ᨨ

 犨�  � ��ᨨᆠ�泐ᨨ vᔼᆠᨨ鼀矄ᆠ├ᨨ�矄� �� v ᨨ矄��ᨨ 犨� ᨨᆠ�泐    盐ᨨ  ᆠᨨ �ᆠ� ᨨ  ├� �ᆠ �ᆠ�ᨨ 犨  ᨨᆠ├  � ᆠ�   �矄 I   盐ᨨ I�矄힘힘힘힘힘힘힘힘힘 ᆠᨨ矄ᨨ ҈ ᲼㝐� 和 ᔼᔼ㡰桌 5



Integer Value Answer

MCQs with One or More than One Correct Answer

꾀矄鼀ᨨᆠ├ᨨ 鼀矄矄ᨨ ҈├��矄ᨨ  �  � ᆠ�   턼犨 �ᆠ 鼀├矄  �q 犨�   ᨨ� ᨨ 꾀 ᨨ� ᨨ  ᨨᆠᨨ ҈ᆠ矄ᨨ  ᨨᆠ├ ᨨ盐� �矄ᆠ  ᨨ 鼀矄矄矄矄 ᨨ犨 �   ��盐 ᲼҈桌

ᨨᆠ├鼀� 矄矄�ᨨ 泐�  ├g㦨҈鼀⏌矄㡰 㡰 q 㦨�° 㡰 q >�°   �ᆠ�ᨨ  ᨨᆠᆠ矄ᨨ  ᨨᆠ├ᨨ犨 矄 ᆠ㡰 q >�°   �ᆠ�ᨨ  ᨨᆠᆠ矄ᨨ  ᨨᆠ├ᨨ犨 矄턼 㡰 q �°   �ᆠ�ᨨ  ᨨᆠᆠ矄ᨨ  ᨨᆠ├ᨨ犨 矄턼

 꾀�ᆠP�矄矄� � � ᨨ犨  �ᆠ�ᨨ 矄矄 鼀�矄 �ᆠ ᨨ犨ᔼ矄矄矄 ᨨ� At㦨꾀 �矄� 矄 ᨨ �鼀   ᨨ� ᨨ ᆠᨨ鼀ᨨ  ᨨ �矄ᨨᆠ�泐�矄v꾀 Qᨨ  矄鼀鼀矄矄矄P�矄ᆠ  ᨨ鼀At㦨ᨨ �  ᨨ� ᨨ 矄� �AB犨�  矄 v �ᆠ�ᨨ 犨

    矄� �鼀泐 �ᆠ tP tQ  矄ᆠ��鼀矄├ 泐P Qᨨᆠ  ᨨ� B

  ᲼҈黨黨㜠㝐├矄桌 㡰

t P < tQ

㡰

t P = tQ

ᆠ㡰

t P > tQ



tP  � ᨨ ᆠ ACB =  � ᨨ ᆠ AB tQ

7



A 

B ᔴ

Match the Following

䰘 꾀ᨨᆠ├ᨨ 鼀矄矄m҈㦨҈├� ᨨ 鼀矄矄m㦨├� ᆠ ᨨ�  矄 ��盐㡰ᨨ  � ᆠ�   犨�  � ᨨ � ᆠ� �ᨨ q�ᨨ盐矄盐矄ᨨ q�� � �矄㜠ᔼ  ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  ᨨᆠ├m҈  �矄 犨泐矄 ᨨ ᆠᨨ �ᆠ� ᨨ 矄�ᆠ  泐 鼀�ᆠ �ᆠ�ᨨ

犨  ᨨᆠ├m   ⼄盐ᨨm㦨ᔼ

�矄㜠ᔼᔼ 矄矄�ᨨ 矄 ᨨ  �ᆠ�ᨨ ᨨ ᨨᆠ├m��  㝐ᆠ  ᆠᨨᆠ 矄矄�ᨨ ᨨ   �ᆠ�ᨨ � �矄㜠ᔼᔼ犨�   �矄�� � �矄㜠ᔼ ᆠ ᨨᨨ矄 ᆠᨨᆠᨨ�ᨨ 

ᆠᆠ�ᨨ  盐ᨨ��泐�矄  ᨨ 泐g ᲼矄 盐� ᨨ鼀�ᨨ   �� 㡰 » ҈錐  ҈҈� 㡰 » 錐

҈� 㡰 »  ᲼꾀 ҈桌 �矄㜠ᔼ �矄㜠ᔼᔼ m҈ m  q㦨� ҈ mg矄� q 턼 q㦨҈  m҈졔m㡰g矄� q  q㦨҈�  mmgᆠᨨ矄q 和 q㦨  m m҈졔m㡰gᆠᨨ矄q q ᔴᨨ  㡰 㜠҈턼㜠҈ 㜠҈和㜠 㡰 㜠턼㜠 㜠和㜠 ᆠ㡰 㜠턼㜠 㜠和㜠 㡰 㜠턼㜠 㜠和㜠 10 Subjective Problems  꾀ᆠ�ᆠ盐 �矄ᆠ犨� �ᨨᨨᨨ ��矄 �鼀�矄ᆠ ᨨ� ᨨ 泐ᨨ ᨨ盐� 矄盐 ᆠ꾀ᨨᆠ├ᨨ 鼀矄矄҈├��矄 ᆠ 矄矄 ᨨ犨  ᆠᨨ㜠 �ᆠ� ᨨ  �ᆠ�ᨨ 犨   ᨨᆠ├ 矄盐 ᆠ矄ᨨ �ᨨᨨ  ᨨ� ᨨ 矄盐 ᆠ�

 ᆠᨨ ᆠ�矄m㦨   �矄ᆠ 矄 ᆠᆠ�ᨨ ᨨ �鼀⏌矄 � ᨨ犨 矄  �  ᆠᆠ�ᨨ ᨨ  ᨨᆠ├犨� 矄ᆠ   ᲼㜠㝐桌 ᨨ �矄ᆠ෌�  ᆠᨨ矄 q =  矄� q =  � �



�鼀⏌矄

q

WWW.JEEBOOKS.IN

EBD_8341 P-28

黨

Physics

犨ᨨᨨᆠ├A Bᨨ ⼄盐鼀矄矄矄ᆠ ᨨ ᨨ盐� � ᆠ�   矄矄 ᨨ犨 �  ��盐␔   犨 犨�  犨ᨨᨨᆠ├矄ᆠᨨ鼀ᨨ  矄鼀� ᨨ  � ᆠ�    �  泐矄 矄�鼀盐 ᨨ盐矄泐䁸ᔼ ��泐 ᨨᆠ├A �矄   m  �    ᨨᆠ├ B ᔴᨨ㜠 �ᆠ�  ᨨ  ├� �ᆠ �ᆠ�ᨨ  ᨨ ᨨᆠ├矄A B 矄ᆠ�泐 g㦨҈鼀⏌矄㡰 ᲼㜠㝐├矄桌 鼀

�º



p

҈



p

 

҈

꾀 

ᆠ    ᆠᨨ �ᆠ�  ᨨ ├� �ᆠ �ᆠ�ᨨ  犨    鼀矄矄矄  矄盐 ᆠ矄�矄� � ᆠ�   鼀├矄   �ᨨ 䰘 犨�   ᨨ� ᨨ  ᲼҈黨҈㜠㝐├矄桌

䰘

꾀 

ᔼ   ��盐鼀矄矄矄m҈m M├��├� �├� 矄ᆠ�泐 ᆠᨨ �ᆠ�  ᨨ  �ᆠ�ᨨ  犨  M  �ᨨ盐 �矄 ᨨ ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨 m҈ M  犨 m �ᨨ盐 �矄 盐泐矄  矄� �矄鼀矄矄矄矄 矄� ��矄 ᆠ泐 ᨨ� ᨨ  犨 P҈ 鼀҈ 矄ᨨ犨 P m 矄� � �矄  ᆠ泐 �ᆠ 犨  P҈   P꾀     ᨨ� ᨨ  ᨨᆠ F �矄 �  ᨨ   鼀矄矄 M ├ g㦨҈鼀⏌矄 ᲼㜠҈㝐├矄桌

ᔼ  鼀矄矄M҈鼀ᨨ矄 ᨨ犨 犨 矄犨� 盐 � ᨨ鼀ᨨᆠ�泐 � �㡰  鼀矄矄ᨨ M҈ ��㡰  矄�ᨨ �    ᨨ� ᨨ ᨨ�ᨨ ᨨ  矄� � g㦨黨鼀⏌矄ᆠ矄� 䰘  ~ - ⏌�㡰  꾀 ᨨ� ᨨ  盐 � ᨨ鼀 ᨨ ᨨ   �  L 矄� � ᨨ   �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ�矄盐 ᨨ  泐 ᨨᆠ F␔ �矄  矄�ᨨ �  ᨨ �矄 ᆠl ᨨ鼀  ᲼҈黨䰘桌  犨   ᨨᆠ�矄� 䁸  犨ᨨᆠ盐矄ᨨ 鼀矄矄矄m҈  mᨨ 犨ᨨ �ᆠ�ᨨ 矄矄 矄ᨨ矄ᨨ ᨨᆠ├A犨 �ᆠ 矄矄ᨨ  ᨨ� ᨨ   ᆠ盐矄ᆠᨨ

ᆠ 泐矄� �犨 �ᆠ 矄矄矄ᨨ盐泐 矄矄 ᨨ犨 �   ��盐 ᨨ犨  ᨨ� ᨨ ᆠᆠ�ᨨ





m P

M

F

b

f

m

m҈ A

㡰 犨 ᨨ 泐 ��鼀 ᨨ鼀矄矄Mᆠ泐矄 ᨨ犨� �   ᨨᆠ矄

҈



㡰  鼀� �盐 ᨨ   ᨨᆠᨨ  �ᆠ�ᨨ 犨 m҈  Mf҈  犨 m �ᨨ盐 f ᨨ�ᆠ盐F��矄 ᨨ盐  f҈㦨f � f҈ f ␔�⼄盐�ᨨ 矄ᨨ 鼀ᨨ�ᨨ ᨨ  鼀矄矄矄 � F  矄�ᨨ �  矄� � ᆠᆠ�ᨨ ᨨ  鼀矄矄矄 꾀�ᆠᨨ 鼀矄矄m矄矄ᨨ  ᨨ� ᨨ  ᨨᨨ犨� 犨 �ᆠ � 矄ᆠᨨ �ᆠ� ᨨ 矄�ᆠ �ᆠ�ᨨ  m ᔼ�矄 矄� ᨨ鼀├  ᨨ 泐鼀ᨨ泐泐� � 鼀� �鼀盐鼀ᨨ矄矄� ᨨᆠF �  鼀�盐�盐 ᨨ F   �ᆠ�ᨨ � 犨 �ᆠ � 矄 ᨨ�  ᲼҈黨䰘㜠䰘㝐├矄桌 㝐矄矄矄 M҈ M   M  ᆠᨨ

ᆠ  泐 矄� �矄 ᨨ

����鼀矄矄犨 �ᆠ 矄矄ᨨ鼀矄矄矄矄  �ᆠ�ᨨ 矄矄 盐泐矄P҈ P矄矄 ᨨ犨 �  �� 鼀矄矄矄鼀ᨨ矄盐ᆠ   ᨨ�ᨨ ᨨ  矄� �犨 P҈ P�  ᨨ � ᆠ�     ᨨ�ᨨ ᨨ  矄� �犨

P M�矄 ᨨ� ᨨ  鼀矄矄矄M M├�

a

f矄 ᨨ盐  犨 ᨨ矄泐矄鼀  �矄ᨨᆠ├矄 ᆠ盐矄㡰 矄盐ᆠ 矄ᨨ  ᆠ盐矄 ᨨ ᨨ矄�  ᨨ犨   矄 ␔ �矄  矄�ᨨ ᨨ  矄� ��  �矄矄�盐�ᨨ 䁸᲼҈黨䰘桌 � ᔼ   ��鼀矄 ᨨ犨   ᨨᆠ├矄AB C A 犨�� 矄├�├� B �├� 矄ᆠ�泐  C f ᆠᨨ �ᆠ�  ᨨ  矄� � � �ᆠ�ᨨ 犨  泐 犨ᨨ矄盐 ᆠ�矄�A�矄  矄泐鼀矄矄矄矄��� ᨨ �  ᨨ 犨犨 �B Cᆠᨨ

ᆠ 泐��   �ᆠᨨ 矄矄� �ᨨ盐  �ᆠ�ᨨ 矄矄盐泐 �   ᨨᆠF ᆠ矄矄泐ᨨ �Cᨨ �  ᨨ� ᨨ 矄盐 ᆠ ᨨ  ᆠᨨ 矄 矄 꾀矄矄盐鼀   �鼀  矄 ᨨ犨 �   ��鼀Bᨨ C Aᨨ B�矄鼀� �    ᨨ盐�  �㦨黨鼀⏌矄㡰 ᲼҈黨䰘桌

WWW.JEEBOOKS.IN

P-29

Laws of Motion

Topic-4 : Circular Motion & Banking of Road 1 1.

2.

5.

MCQs with One Correct Answer

A disc rotates about its axis of symmetry in a hoizontal plane at a steady rate of 3.5 revolutions per second. A coin placed at a distance of 1.25cm from the axis of rotation remains at rest on the disc. The coefficient of friction between the coin and the disc is (g = 10m/s2) [Main Online April 15, 2018] (a) 0.5 (b) 0.7 (c) 0.3 (d) 0.6 A conical pendulum of length 1 m makes an angle q = 45° w.r.t. Z-axis and moves in a circle in the XY plane.The radius of the circle is 0.4 m and its centre is vertically below O. The speed of the pendulum, in its circular path, will be : [Main Online April 9, 2017] (Take g = 10 ms–2) Z (a) 0.4 m/s

(a)

(c) 5 6.

O q

(b) 4 m/s (c) 0.2 m/s 3.

7.

X Y

q f O

4.

(b)

1 sin f = cos q 2 3 sin f = cos q 4

2 (c) sin f = cos q (d) 3 A ball of mass (m) 0.5 kg is attached to the end of a string having length (L) 0.5 m. The ball is rotated on a horizontal circular path about vertical axis. The maximum tension that the string can bear is 324 N. The maximum possible value of anguar velocity of ball (in radian/s) m is [2011] (a) 9 (b) 18 (c) 27

L

8.

v

v

(b)

(d)

v

v

True / False

A simple pendulum with a bob of mass m swings with an angular amplitude of 40°. When its angular displacement is 20°, the tension in the string is greater than mg cos 20°. [1984 - 2 Marks] 6

C

(d) 2 m/s A particle is released on a vertical smooth semicircular track from point X so that OX makes angle q from the vertical (see figure). The normal reaction of the track on the particle vanishes at point Y where OY makes angle f with the horizontal. Then: [Main Online April 19, 2014]

(a) sin f = cos f

A small block is shot into each of the four tracks as shown below. Each of the tracks rises to the same height. The speed with which the block enters the track is the same in all cases. At the highest point of the track, the normal reaction is maximum in [2001S]

MCQs with One or More than One Correct Answer

A wire, which passes through the hole in a small bead, is bent in the form of quarter of a A circle. The wire is fixed vertically on ground as shown in the figure. The bead is released from near the top of the wire and it slides along the wire 90° without friction. As the bead B moves from A to B, the force it applies on the wire is [Adv. 2014] (a) always radially outwards (b) always radially inwards (c) radially outwards initially and radially inwards later (d) radially inwards initially and radially outwards later A simple pendulum of length L and mass (bob) M is oscillating in a plane about a vertical line between angular limit – f and + f . For an angular displacement q ( | q | < f ), the tension in the string and the velocity of the bob are T and V respectively. The following relations hold good under the above conditions : [1986 - 2 Marks] (a) T cos q = Mg. MV 2 L (c) The magnitude of the tangenial acceleration of the bob | aT | = g sin q (d) T = Mg cos q

(b) T – Mg cos q =

(d) 36

WWW.JEEBOOKS.IN

EBD_8341 P-30

Physics

10 Subject Problems 꾀矄鼀ᨨᨨ 矄鼀�ᆠ�ᆠ盐犨�㜠ᆠ├ᨨ  �盐矄R�矄 �  �  �ᆠ 졠  ᨨ 鼀矄矄矄矄矄� �ᨨ  盐  � R⏌�矄ᆠ  ᨨ ᨨ犨矄ᨨ� Oᨨ  犨�㜠 ᆠ├꾀矄鼀� �ᨨ 鼀矄矄m犨 �ᆠ ᆠ 矄� ᨨ  ᆠ├ �矄ᆠ  ᨨ ᨨ  ᨨ   矄� �  � � �矄  矄�ᨨ 泐ᨨ� P矄盐ᆠ    矄� �鼀├矄  �ᨨ   犨�    �ᆠ  矄� � ᆠᨨ 矄  K㦨 mg⏌R ᔴᨨ 矄�  � 矄 犨    � ��矄矄   �㡰 犨   ᨨ 泐 ��鼀ᨨ   � � ��㡰 鼀�     � �ᆠᆠ�ᨨ ᨨ   � �   ᨨ鼀ᆠ�ᨨ  ᲼҈黨黨㜠�㝐├矄桌

黨

Answer Key Topic-1 : Ist, IInd & IIIrd Laws of Motion ҈ ҈҈

㡰  㡰 �㡰 ҈ 矄

 㡰 ҈  㡰

 㡰 ҈ 㡰

� 㡰 ҈� 㡰

 㡰

䰘 㡰

 㡰

黨 㡰

҈ 㡰

҈ 矄

Topic-2 : Motion of Connected Bodies, Pulley & Equilibrium of Forces ҈ ҈҈

㡰 㡰

 㡰 ҈ 㡰

 㡰

 㡰

� 㡰

 㡰

䰘 ᆠ㡰

 㡰

黨 ᆠ㡰

䰘 㡰 ҈䰘 㡰 䰘 㡰

 㡰 ҈ 㡰

黨 㡰 ҈黨 㡰

Topic-3 : Friction ҈ 㡰 ҈҈ 㡰 ҈ �㡰

 ᆠ㡰 ҈ ᆠ㡰  �㡰

 㡰 ҈ 㡰  㡰

 㡰 � 㡰  㡰 ҈ 㡰 ҈� 㡰 ҈ 㡰  矄 � ᆠ㡰  㡰

҈ 㡰  㡰

Topic-4 : Circular Motion & Banking of Road ҈



 㡰

 ᆠ㡰

 㡰

� 㡰

 矄

䰘 㡰

 ᆠ㡰

WWW.JEEBOOKS.IN

P-31

Work, Energy and Power

5

Work, Energy and Power

Topic-1 : Work Done by Constant & Variable Force 1 ҈





MCQs with One Correct Answer

꾀矄ᨨ  盐矄 矄  ᨨ  ᨨ   ᨨ盐�  ᨨ� ᨨ   ᨨ鼀 矄盐 ᆠ  �矄   ᨨᆠ ᨨ   ᨨ   �矄 ᆠ ᨨ ҈�鼀   �矄ᨨ�矄矄�泐�   �矄� ᨨᆠ 盐ᆠ矄� 泐犨�  �矄 ᆠᨨ҈ ᨨ �矄 ᆠ ᨨ盐� 犨 �ᆠ  ᨨ  矄 鼀ᨨ �矄鼀 ␔  �矄   犨ᨨ├  ᨨ  泐   矄ᨨ  盐� �   ᨨ 鼀ᨨ鼀 ᨨ  ᨨ 䁸 ᲼㝐� 和 ᔼᔼ㡰桌 㡰  㡰 䰘 ᆠ㡰 �黨 㡰 �� B C

q A 꾀矄鼀ᨨᆠ├矄矄矄�� � ᨨ犨  ᨨ鼀ᨨ� Bᨨ 

� ᆠ�   AB犨 �ᆠ �矄鼀├� �  �q犨�   ᨨ� ᨨ 矄ᆠ�ᨨ BC�矄矄鼀ᨨᨨ   鼀� � �矄ᆠ�ᨨ

CA�矄ᨨ盐� 犨� ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ mᔼ�矄 ᨨ盐    ᨨᆠ├ᆠᨨ鼀矄ᨨ矄矄�ᆠ 矄 ᨨᨨ鼀 ᨨ� A㡰ᨨ  � ᆠ�   ᔼ BC = AC ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ �矄 �� 泐m㦨k q 盐ᨨ k�矄[㝐� 2 Sep.2020 (I)] 㡰 ҈ 㡰  ᆠ㡰  㡰  r ᔴᨨ 矄�  ᨨᆠ F = - x�ˆ + yˆ  犨ᨨ├ ᨨ 泐 �矄 ᨨᆠ� 鼀ᨨ� ��ᆠ ᨨ鼀ᨨ� 꾀 ҈㡰ᨨ ҈㡰 ᨨ � � 矄�鼀 �矄 ⼄盐 ��矄� 和ᔼ盐 �矄㡰 ᲼㝐� 黨  ᔼ㡰桌

҈   ᆠ㡰 ҈ 㡰    꾀 ᨨᆠ├ ᨨ 鼀矄矄鼀 �矄 ├ ᨨ    ᨨ鼀 犨 �ᆠ  矄矄 ᨨ鼀 矄 犨�  ᆠᨨ 矄  ᆠᆠ�ᨨ  �⏌ 盐犨  矄 矄 ᨨ犨 �  ��犨ᨨ├ ᨨ 泐 ᨨ鼀ᆠ�ᨨ ᨨ ᨨᆠ├�

�鼀�矄    ᲼㝐� ҈   ҈黨 ᔼ㡰桌

㡰  

㡰 -

�



㡰

鼀 �   

㡰

鼀 �  

鼀 �     꾀ᨨ 泐ᨨ 鼀矄矄矄矄鼀ᨨ� � ᨨ鼀矄ᨨ � 㜠 �矄矄ᨨ  �矄ᨨᆠ�泐�矄矄  =  矄 犨 �矄ᆠᨨ 矄 矄  �矄  �矄 ᆠᆠᨨ 泐 ᨨ 泐 ᨨ犨ᨨ├ ᨨ  泐  ᨨᆠ矄ᆠ� �ᨨ  ᨨ 泐�   �矄矄ᆠᨨ    矄ᨨ  鼀ᨨ�ᨨ �矄᲼㝐� 졠 � 꾀�҈҈桌 ҈   ҈ 鼀  㡰 鼀    ᆠ㡰 鼀    㡰 鼀    㡰   ␔  盐㜠 �矄矄ᆠ  泐 �矄 ᆠ � 矄 矄ᨨ� � ᨨᆠᨨ 鼀� �盐  㦨 졔 犨   ᆠᨨ 矄 矄 犨ᨨ├ ᨨ � 矄ᆠ � � 盐 矄ᆠ  盐㜠 泐�矄 ᲼㝐� ҈桌 ᆠ㡰 



㡰  + 

㡰

  + ᆠ㡰  

҈ æ   ö 㡰  çç  +  ÷÷ è ø

(

҈  +  

)

WWW.JEEBOOKS.IN

EBD_8341 P-32

7.

8.

Physics

The work done on a particle of mass m by a force, é ù x y ˆj ú Kê iˆ + 2 2 32 2 2 32 (x + y ) êë ( x + y ) úû (K being a constant of appropriate dimensions), when the particle is taken from the point (a, 0) to the point (0, a) along a circular path of radius a about the origin in the x – y plane is [Adv. 2013] Kp Kp 2K p (a) (b) (c) (d) 0 a a 2a If W1, W2 and W3 represent the work done in moving a particle from A to B along three different paths 1,2 and 3 respectively (as shown) in the gravitational field of a point mass m, find the correct relation between W1, W2 and W3 [2003S] B

(a) W1> W2 > W3 (b) W1= W2 = W3

9.

2

1

Integer Value Answer

11. A light inextensible string that goes over a smooth fixed pulley as shown in the figure connects two blocks of masses 0.36 kg and 0.72 kg. Taking g = 10 m/s2, find the work done (in joules) by the string on the block of mass 0.36 kg during the first second after the system is released from rest. [2009] 3

m

Numeric Answer

12. A particle is moved along a path AB-BC-CD-DE-EF-FA, as ur shown in figure, in presence of a forced F = (ayi$ + 2ax $j ) N , where x and y are in meter and a = –1Nm–1. The work done on the particle by this force ur [Adv. 2019] F will be ___ Joule.

2 3

(c) W1< W2 < W3 (d) W2> W1 > W3

10. A uniform chain of length L and mass M is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, the work required to pull the hanging part on to the table is [1985 - 2 Marks] (a) MgL (b) MgL/3 (c) MgL/9 (d) MgL/18

A

y

A force F = - K ( yiˆ + xjˆ) (where K is a positive constant) acts on a particle moving in the xy plane. Starting from the origin, the particle is taken along the positive x axis to the point (a, 0), and then parallel to the y axis to the point (a, a), The total work done by the force F on the particle is [1998S - 2 Marks] (a) – 2Ka2 (b) 2Ka2 (c) – Ka2 (d) Ka 2

A

1.0

B

D

.5 F

C

E 0.5

0

x

1.0

Topic-2 : Energy 1 1.

MCQs with One Correct Answer

A particle moves in one dimension from rest under the influence of a force that varies with the distance travelled by the particle as shown in the figure. The kinetic energy of the particle after it has travelled 3 m is : [Main 7 Jan. 2020 II]

3.

4.

1

1 (d) n 2 n n A body of mass 1 kg falls freely from a height of 100m, on a platform of mass 3 kg which is mounted on a spring having spring constant k = 1.25 × 106 N/m. The body sticks to the platform and the spring’s maximum compression is found to be x. Given that g = 10 ms–2, the value of x will be close to : [Main 11 April 2019 (I)] (a) 40 cm (b) 4 cm (c) 80 cm (d) 8 cm A uniform cable of mass ‘M’ and length ‘L’ is placed on a

(a) n

(b)

2

(c)

th

2.

(a) 4 J (b) 2.5 J (c) 6.5 J (d) 5 J A spring whose unstretched length is l has a force constant k. The spring is cut into two pieces of unstretched lengths 11 and l2 where, l1 = nl2 and n is an integer. The ratio k1/k2 of the corresponding force constants, k1 and k2 will be: [Main 12 April 2019 (II)]

æ 1ö horizontal surface such that its ç ÷ part is hanging è nø below the edge of the surface. To lift the hanging part of the cable upto the surface, the work done should be: [Main 9 April 2019 (I)] 2 MgL MgL MgL (a) (b) (c) (d) nMgL 2 2 2n n n2

WWW.JEEBOOKS.IN

P-33

Work, Energy and Power

5.

A particle moves in one dimension from rest under the influence of a force that varies with the distance travelled by the particle as shown in the figure. The kinetic energy of the particle after it has travelled 3 m is : [Main 8 April 2019 (I)]

11. A point particle of mass m, moves long the uniformly rough track PQR as shown in the figure. The coefficient of friction, between the particle and the rough track equals m. The particle is released, from rest from the point P and it comes to rest at a point R. The energies, lost by the ball, over the parts, PQ and QR, of the track, are equal to each other, and no energy is lost when particle changes direction from PQ to QR. The value of the coefficient of friction m and the distance x (= QR), are, respectively close to : [Main 2016] P

6.

(a) 4 J (b) 2.5 J (c) 6.5 J (d) 5 J A block of mass m, lying on a smooth horizontal surface, is attached to a spring (of negligible mass) of spring constant k. The other end of the spring is fixed, as shown in the figure. The block is initally at rest in its equilibrium position. If now the block is pulled with a constant force F, the maximum speed of the block is:[Main 9 Jan. 2019 (I)] m

(a) 7.

2F mk

(b)

F p mk

(c)

F

pF mk

(a) -

k 4a

(c) zero

2

(b)

10.

mk

k 2r 2

. Its total energy is: [Main 2018]

k

2a 2 3 k (d) 2 a2

A body of mass m = 10–2 kg is moving in a medium and experiences a frictional force F = –kv2. Its intial speed is v0 = 10 ms–1. If, after 10 s, its energy is

9.

F

A particle is moving in a circular path of radius a under the action of an attractive potential U = -

8.

(d)

1 2 mv0 , the value of k 8

will be: [Main 2017] (a) 10–4 kg m–1 (b) 10–1 kg m–1 s–1 (c) 10–3 kg m–1 (d) 10–3 kg s–1 An object is dropped from a height h from the ground. Every time it hits the ground it looses 50奠 of its kinetic energy. The total distance covered as t ® ¥ is [Main Online April 8, 2017] 8 5 h (a) 3h (b) ¥ (c) (d) h 3 3 A time dependent force F = 6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the [Main 2017] force during the first 1 second will be (a) 9 J (b) 18 J (c) 4.5 J (d) 22 J

h=2m

30° Horizontal Surface

R Q

(a) 0.29 and 3.5 m (b) 0.29 and 6.5 m (c) 0.2 and 6.5 m (d) 0.2 and 3.5 m 12. A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? Fat supplies 3.8 × 107 J of energy per kg which is converted to mechanical energy with a 20奠 efficiency rate. Take g = 9.8 ms–2 : [Main 2016] –3 –3 (a) 9.89 × 10 kg (b) 12.89 × 10 kg (c) 2.45 × 10–3 kg (d) 6.45 × 10–3 kg 13. A particle is moving in a circle of radius r under the action of a force F = ar2 which is directed towards centre of the circle. Total mechanical energy (kinetic energy + potential energy) of the particle is (take potential energy = 0 for r = 0) : [Main Online April 11, 2015] 5 3 4 3 1 3 αr ar (b) ar (c) (d) ar3 6 3 2 14. A block of mass m = 0.1 kg is connected to a spring of unknown spring constant k. It is compressed to a distance x from its equilibrium position and released from rest. After approaching half the distance æç x ö÷ from equilibrium è 2ø position, it hits another block and comes to rest momentarily, while the other block moves with a velocity 3 ms–1. The total initial energy of the spring is : [Main Online April 10, 2015] (a) 0.3 J (b) 0.6 J (c) 0.8 J (d) 1.5 J

(a)

th

æ1ö 15. A bullet looses ç ÷ of its velocity passing through ènø one plank. The number of such planks that are required to stop the bullet can be: [Main Online April 19, 2014] (a)

n2 2n 2 (b) 2n - 1 n -1

(c) infinite

(d) n

WWW.JEEBOOKS.IN

EBD_8341 P-34

҈

҈䰘

Physics

犨ᨨ 矄� �矄 ᨨ  ᨨᆠ ᆠᨨ 矄 矄  ⏌鼀 和� �꾀㡰 ⏌鼀 和� �㡰ᨨ�  ᨨ� �

矄�矄 ᆠᨨ鼀� �ᨨ �矄ᆠᨨ鼀矄矄 泐䰘�ᆠ鼀  E E �ᨨᨨ  �泐矄ᨨ � 꾀 �矄 A    A �矄 EB EB ⼄盐 ᲼㝐� 졠 � 꾀�黨҈桌 ᨨ  ҈ 黨  㡰 㡰 ᆠ㡰 㡰  黨 ҈  꾀ᨨᆠ├ᨨ 鼀矄矄├��矄 ᨨ鼀ᨨᨨ �  㜠 �矄ᔼ�矄 矄  ᨨ鼀㦨ᨨ 犨 矄��矄矄盐ᆠ ᨨ�鼀㜠    ᨨᆠF t㡰�  x �ᆠ�ᨨ   ᨨᆠF t㡰�矄 犨� t矄矄 ᨨ犨 �   ��盐 ├� �ᆠ �泐ᨨ   ᨨᆠ├ �矄ᆠᨨ 矄�矄 ᲼҈桌 F t㡰

 꾀 � 矄� �犨� 矄� �㜠ᆠᨨ 矄 k�矄 盐 � ᨨ鼀  ᆠ�� � ᨨᆠ├ᨨ 鼀矄矄M�矄ᆠ  ᨨ�矄ᨨ犨 

鼀矄矄�矄矄 犨�  矄� �� ��泐盐 矄ᆠ  

  鼀 �鼀盐鼀  矄�ᨨ �  矄� ��矄 ᲼和桌 Mg Mg Mg Mg 㡰 ᆠ㡰 㡰 k k k k ҈ 꾀�ᆠ犨 �ᆠ �矄ᆠᨨ 矄�  ᨨ鼀ᨨᨨ � x㜠 �矄 �矄 矄盐ᆠ  ᨨ  ᨨᆠ �    矄鼀 �ᆠ�ᨨ  犨 �ᆠ �矄犨�   �矄 ᆠxᨨ  �ᆠ ᨨ鼀 ᨨ��� 矄 F x㡰㦨kx졔axk aᨨ矄��ᆠᨨ 矄 矄 ᨨ x ³    盐 ᆠ�ᨨ  ᨨ鼀ᨨ  ᨨ � �泐U x㡰ᨨ  �ᆠ�矄 ᲼和桌

㡰

U(x)

U(x)

㡰

㡰 �

X

㡰

X



X

N

㡰 䰘� �s

ᆠ㡰 �

s

O

t U(x)

҈

㡰 ҈ 꾀ᨨᆠ├ B㡰�矄ᆠ  ᨨ犨ᨨ盐 矄ᆠ  矄� �矄S҈ S犨� 矄� �ᆠᨨ 矄 矄k k矄ᆠ�泐 矄 ��ᔼ㡰

ᨨ  矄ᆠ  ᨨ�  �ᆠ矄盐ᨨ矄M҈ M ᨨᆠ  ᨨ 犨矄 矄� �矄 矄盐ᨨ矄  ����鼀矄矄 �矄 ᨨ �ᆠ�ᨨ  泐犨   ᨨᆠ├B�矄 �矄ᆠ ᨨ犨 矄犨҈泐矄鼀 �矄 ᆠx ��盐ᔼᔼ㡰 矄  ᨨᆠ├盐 矄 鼀ᨨ矄 鼀 �鼀盐鼀 �矄 ᆠyᨨ犨 矄犨�矄ᆠ鼀 矄x y 鼀矄盐 犨� 矄ᆠᨨ ⼄盐���盐鼀ᨨ矄��ᨨ ᨨ  ᨨᆠ├B �ᨨy⏌x�矄 ᲼桌  ҈ M҈ M S S҈  ᔼ B x

 M

҈黨

S

҈ S҈

B



ᔼᔼ

x 㡰  㡰  ᆠ㡰 ҈⏌ 㡰 ҈⏌ 꾀�ᆠ�矄ᆠ 泐 ᨨᆠF㦨kx犨 k�矄졔 ᆠᨨ 矄 ᔼ矄ᨨ � �泐x㦨�矄 ᨨ␔ �ᆠ ᆠ盐 ᆠᨨᆠ泐矄 矄 ��ᨨ ᨨ ᨨ � �泐ᨨ  ᨨᆠ├犨� 矄ᆠᨨx ᲼和桌 U

U(x)

ᆠ㡰

X

 꾀矄� �ᨨ  ᨨᆠ㜠ᆠᨨ 矄  k�矄ᆠ盐� ᨨ犨ᨨ�ᆠ矄矄盐ᆠ  ᨨ �ᆠ�矄 ᨨ盐  � ᨨ  ᨨ     ᨨ ��ᆠ犨�  ᨨᆠ㜠ᆠᨨ 矄 ᨨ ᲼҈黨黨黨和㜠㝐├矄桌 㡰 ⏌㡰k 㡰 ⏌㡰k ᆠ㡰 k 㡰 k  犨ᨨ鼀矄矄矄ᨨ ҈�鼀 �鼀鼀ᨨ� �犨� ⼄盐├� �ᆠ  ��矄  �ᨨ ᨨ    鼀� �盐 矄 ᨨ   � �  鼀ᨨ鼀 �矄 ᲼҈黨桌 㡰 ҈ 㡰 㡰 ҈҈  ҈ ᆠ㡰 ҈ 2

Integer Value Answer

 ᔴᨨ 矄�  ��ᆠ矄  �PQ �  �ᆠ  犨� OP㦨鼀 OQ㦨鼀꾀ᨨᆠ├ᨨ 鼀矄矄҈├��矄盐 ᨨ � � ᨨ鼀PᨨQ犨�  ᨨᆠᨨ ҈犨 �ᆠ �矄 犨泐矄ᨨ� PQ 矄  ��盐�� 㡰꾀矄矄盐鼀� �

ᨨ �ᆠ�ᨨ 矄矄ᨨ矄矄矄 ├� �ᆠ �泐ᨨ  ᨨᆠ├犨 

� ᆠ 矄Q�矄  n 맔҈㡰 ᨨ盐矄 盐ᨨ n �矄 ├ ᆠᆠ�ᨨ  盐ᨨ��泐㦨҈鼀矄㡰 ᲼꾀 ҈桌 Q

U

鼀

㡰

x

㡰

x

黨 U

ᆠ㡰

O

U x



x

鼀

P

� 꾀ᨨᆠ├ᨨ 鼀矄矄҈├��矄ᆠ  ᨨ矄� �ᨨ  ᨨᆠ㜠 ᆠᨨ 矄 ⏌鼀 ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨   ᨨᆠ├   ᨨᨨ�矄҈ᔼ ��泐 ᨨᆠ├�矄矄  矄� ��矄盐 㜠矄ᆠ  꾀 �鼀盐矄�矄�� ᨨ ᨨᆠ├

WWW.JEEBOOKS.IN

P-35

Work, Energy and Power

矄矄 ᨨ犨 �   ��盐 ᨨᆠ├矄� 矄 �矄 ᆠᨨ  鼀 ᆠᨨ鼀矄ᨨ矄 ᨨ  �矄�鼀 � ��ᨨᆠ�泐ᨨ  ᨨᆠ├� 鼀⏌矄�矄㦨⏌҈  �矄 ᲼҈҈桌

3 

䰘

Numeric Answer

꾀ᆠ�ᆠ├ᨨ 鼀矄矄҈�├��矄 ᨨ犨 �ᆠ泐盐泐 ᨨ犨� �鼀ᆠ � 矄ᨨ ��矄矄ᨨ鼀 �鼀盐鼀 �� ᨨ  鼀 � � 鼀ᆠ � ᔼ  盐矄 � �  �矄  ᆠᨨ 矄  ᨨᆠ F ᨨ     鼀ᨨ矄 ᨨ� ᨨ 泐 �矄 ᆠᨨ 鼀犨 �盐 ᆠ � �   盐ᨨ F � 㡰�矄 g㦨҈鼀矄㡰힘힘힘힘힘힘힘힘힘힘 [Main 3 Sep. 2020 (I)] 꾀�ᆠ m 㦨├�㡰矄� 矄 ᨨ犨  �ᆠ�ᨨ 矄矄ᆠ├ 꾀졠ᔴ㡰 矄� � ᨨ鼀矄ᨨ� A �� 鼀㡰꾀 ᆠ � � C �ᆠᆠᨨ � 盐矄ᨨ鼀ᨨ 泐� �矄ᨨᆠ� ␔  �ᆠ � ��矄 �� 矄ᨨ� P �� ҈鼀㡰  ├� �ᆠ �泐ᨨ  �ᆠ � J㡰�矄 ��盐 犨 �矄 矄ᆠ 鼀�ᆠ  ᨨᨨ矄ᆠ錐├g 㦨҈鼀矄㡰¾¾¾ . ᲼Main 䰘  ᔼ㡰桌

 㡰 v -  gh =

҈ gR 

 gR 㡰 v -  gh =  ᆠ㡰  ᆠ � ᨨᆠ⼄盐� ᨨ� 矄x z�矄 ᨨ 㡰  ᆠ � ᨨᆠ⼄盐� �矄鼀 �鼀盐鼀ᨨ� 矄x  z 黨 꾀�ᆠᨨ 鼀矄矄m�矄� ��泐矄 ᨨ��� ᔼ�矄 矄盐ᆠ ᨨ ᨨᆠ 矄矄鼀ᨨ� �ᨨ � x㜠 �矄ᔼ矄 ├� �ᆠ �泐Kᆠ  �矄犨� �鼀矄 ⧤⏌ 㦨g犨 g �矄ᨨ矄��ᆠᨨ 矄 ᨨ ᨨ� �鼀 矄�ᨨ 矄␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 㡰盐䁸 ᲼꾀 ҈桌 㡰  ᨨᆠ� ᨨ  �ᆠ�矄ᆠᨨ 矄  㡰 矄 ᨨ  �ᆠ�矄ᨨᨨ�ᨨ ᨨ�鼀 ᆠ㡰  �矄 ᆠᨨ  �ᆠ ᨨ鼀 ᨨ��� � ᆠ矄矄 � 泐犨� �鼀 㡰  ᨨᆠ�矄ᆠᨨ 矄�  꾀矄鼀矄矄鼀ᨨ� � ᨨ鼀Aᨨ �  ᆠ├矄矄 ᨨ犨

�   ��盐和盐 ᆠAB 矄 �ᆠ�ᨨ  ᨨ鼀AᨨB  ᨨ矄犨� ᨨ盐矄�� �和盐 ᆠBC�矄 �ᆠ�ᨨ 矄矄KAKB KC├� �ᆠ ��矄ᨨ  AB C矄ᆠ�泐



᲼㜠�㝐҈桌 C

�� 

A

A

P C

鼀

hC

hA

B

O

6 

㡰

hA > hC 錐 K B > KC

㡰

hA > hC 錐 KC > K A

ᆠ㡰

hA = hC 錐 K B = KC



hA < hC 錐 K B > KC

MCQs with One or More than One Correct Answer

꾀矄盐  矄├矄盐鼀 鼀├矄  � 犨�   ᨨ� ᨨ ⏌矄 矄矄 矄矄 ᨨ犨  �   ��盐㡰  ᨨᨨ鼀ᨨ  鼀犨� 矄 v 犨 矄ᨨ盐 ᨨ盐 ᨨ矄鼀�ᆠ�ᆠ盐 xyz ᨨ  �盐矄R 盐� �犨 �ᆠ  ⏌ 矄 ᆠ 矄鼀 �鼀盐鼀 �� h ᨨ� y㡰 ᨨ鼀 �ᨨ盐 矄矄 ᨨ犨  �    ��盐꾀矄矄盐鼀      �泐ᨨ矄矄 �矄

����   ᨨᆠ⼄盐�  ᨨ �矄盐   �� 矄 ᨨ� �矄ᨨ�  泐 �矄⏌  犨�� ᨨ 泐   g�矄  ᆠᆠ�ᨨ  盐ᨨ��泐㡰 ᲼꾀 桌 z R

y

x h 

҈ 꾀矄ᨨ � ᨨ矄� �ᨨ  � �矄犨 � � �ᆠ ᆠ�ᆠ犨�  ᨨ  ᨨ  矄� � ᆠ 꾀 ᆠ� � 矄 ᨨ �鼀 矄ᨨ �矄�矄ᨨ犨矄ᨨ矄��ᨨ    矄矄 u 鼀� �盐 ᨨ  ᆠ  �� �矄 ᨨᆠ�泐矄 � ᆠ 矄  ᨨ矄��ᨨ  犨    矄� � �矄 ᨨ� ᨨ �矄 ᲼҈黨黨和㜠㝐├矄桌 㡰

u  -  gL

㡰

gL

ᆠ㡰

u  - gL



 u  - gL㡰

 꾀�ᆠ�矄ᆠ 盐ᨨ 泐 ᨨᆠᨨ ᆠᨨ 矄 鼀� �盐  犨 �ᆠ �矄 犨泐矄  �ᆠ盐 ᨨ   ᨨᆠ�泐 ᨨ   �ᆠ 鼀ᨨ�ᨨ ᨨ  �ᆠ├矄ᆠ�  ᔼ ᨨᨨ犨矄  ᲼҈黨䰘㜠㝐├矄桌 㡰 �矄ᨨᆠ�泐�矄ᆠᨨ 矄  㡰 �矄ᆠᆠ�ᨨ �矄ᆠᨨ 矄  ᆠ㡰 �矄├� �ᆠ �泐�矄ᆠᨨ 矄  㡰 �鼀ᨨ矄� ᆠ�ᆠ盐 

WWW.JEEBOOKS.IN

EBD_8341 P-36

Physics

Match the Following

7

 꾀�ᆠᨨ 盐 �鼀矄矄�矄鼀ᨨ� �ᨨ � x㜠 �矄盐  � 盐 ᆠᨨ  ᨨᆠ �矄ᨨ �泐�矄ᆠᨨ 矄  ᨨ盐ᨨ矄矄� ᨨ鼀矄ᨨ  ᨨ � �泐ᨨ  �ᆠ�� � ᆠᨨ盐鼀 ᔼ a Uᆠᨨ 矄 矄㡰㝐ᆠ  ᨨ � ��矄� ᆠᨨ盐鼀

ᔼᨨ ᆠᨨ矄ᨨ � �矄鼀  矄㡰� ᆠᨨ盐鼀 ᔼᔼ ᔴᨨ盐鼀 ᔼ U 꾀㡰 U҈ x㡰㦨 

㡰

U x㡰㦨

ᔴᨨ盐鼀 ᔼᔼ é æ x ö ù ê҈ - ç ÷ ú êë è a ø úû



U  æ x ö ç ÷  èaø

ù  é æ x ö   ê- æ x ö ú ç ÷ ᔴ㡰 ç ÷  êë è a ø úû èaø ù é  ê x  ҈ æ x ö ú ç ÷ 㡰 U x㡰㦨   êë a  è a ø úû

U U x㡰㦨 

㡰

 ᨨᆠᆠ� �ᨨ  �ᆠ�矄 ᨨx㦨a

⼄㡰

 ᨨᆠᆠ� �ᨨ  �ᆠ�矄 ᨨx㦨

㡰

 ᨨᆠᆠ� �ᨨ  �ᆠ�矄 ᨨx㦨a

矄㡰

�ᆠ � ᆠ矄 ᆠ� ᨨᆠᨨ犨 矄x㦨�  ��ᨨ x

㡰

�ᆠ犨� ᨨ �泐

Comprehension/Passage Based Questions

8

꾀和和꾀෌E 꾀矄鼀ᨨᆠ├ᨨ 鼀矄矄҈├��矄矄  ᨨ鼀矄 ᨨᨨ  ᨨ盐� ᆠ├ ᆠ├�矄ᆠ�ᆠ盐ᆠᨨ  �盐矄鼀 ᨨᆠ├ 矄� 矄ᨨ � ᆠ├犨� ᨨ盐ᨨ� �  �ᆠ�ᨨ  ᨨᆠ ᆠ矄ᨨ ��   �ᆠ�ᨨ ᨨᨨ矄�ᨨ � 矄  ᨨ盐矄ᨨᆠ�泐

犨ᨨ├ ᨨ � ᨨᆠᨨ鼀� �  �ᆠ�ᨨ 盐ᨨ ᨨ� 턼矄 矄 ᨨ犨 �   ��盐ᨨ犨�矄҈� ├ ᆠᆠ�ᨨ  盐ᨨ��泐�㦨҈鼀矄㡰 泐

᲼꾀 ҈桌

 







 鼀� �盐 ᨨ   ᨨ鼀ᆠ�ᨨ  ᆠ矄ᨨ    ᨨᆠ├ ᨨ� 턼�矄 㡰 䰘�

㡰 

ᆠ㡰 ҈҈�

㡰 �

� 矄 ᨨ  ᨨᆠ├犨  �ᆠ 矄 ᨨ� 턼�矄 㡰 �鼀矄҈ ᆠ㡰

҈  鼀矄 -҈

㡰 ҈鼀矄҈ 㡰 鼀矄҈

9

U ᆠ ᨨ矄ᆠ�ᨨ盐 ᨨ� x㦨 

Assertion and Reason Type Questions

 和T꾀TE㝐ENT҈꾀ᨨᆠ├ᨨ 鼀矄矄m矄矄鼀ᨨ� �ᨨ  ᨨ盐�  ᨨ� ᨨ 矄盐 ᆠ犨� ᨨᆠ�泐vᔼ矄ᨨ矄 盐ᨨ �ᆠ�ᨨ 犨  ᨨᆠ├  矄盐 ᆠ 鼀ᨨ� �  ᨨ盐� ᆠ�  �矄 ᆠ 矄盐 ᆠ�矄 ᨨ犨� ᨨ

 �ᨨ  犨�   ᨨ� ᨨ   矄鼀ᨨᆠ├�矄 鼀 ᨨ�ᨨ盐ᨨ  矄盐 ᆠ犨�  矄鼀� ��ᨨᆠ�泐 v  ᆠ矄�  鼀ᆠ  �ᆠ �泐�  矄ᆠᨨ 矄�盐�ᨨ �矄矄鼀   �   �矄矄�盐�ᨨ  和T꾀TE㝐ENT ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨   ᨨᆠ├  矄盐 ᆠ ᆠ矄矄犨�  � ᆠ矄�    �ᨨ � ᆠ� �ᨨ  ᲼䰘桌 㡰 和鼀 ҈�矄 盐和鼀 �矄 盐錐和鼀  �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 ҈ 㡰 和鼀 ҈�矄 盐和鼀 �矄 盐錐和鼀  �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 ҈ ᆠ㡰 和鼀 ҈�矄 盐和鼀 �矄 矄 㡰 和鼀 ҈�矄 矄和鼀 �矄 盐 10 Subjective Problems 䰘 꾀矄� �犨� ᨨ   �  ᨨ ��� 犨矄矄� �ᨨ  �   �ᆠ�ᨨ 矄矄盐泐 �矄 ᆠᨨ 鼀 ᨨ鼀 犨 矄ᨨ� 鼀矄矄M㦨├�ᆠ  ᨨ� �矄 ᆠᨨ ҈鼀 ᨨ鼀 犨꾀鼀矄矄m 㦨�├�ᆠ     M  �矄  矄矄ᨨ   矄� ��矄 ᨨ� ᨨ 犨  犨   盐泐 �ᆠ泐ᨨ  盐泐␔  犨�  矄 m 犨� 犨 �ᆠ  鼀矄矄M犨� �  犨犨   鼀矄矄m�矄矄 䁸 ᲼҈黨�㜠㝐├矄桌

WWW.JEEBOOKS.IN

P-37

Work, Energy and Power



꾀� ├�ᨨᆠ├矄� 矄 ᨨ鼀 ᨨ� A 矄 ��㡰ᨨ  ᨨ� ᨨ ᆠ├犨�  � ��矄 ᨨ 鼀⏌矄ᨨ犨 矄 犨�� 矄矄 ᨨ� ᨨ  矄� � ᨨ   �  ҈ 鼀   ᨨᆠ ᆠᨨ 矄    犨ᨨ ⏌鼀   AB ᨨ    ᆠ├  �矄 �ᆠ�ᨨ 矄矄  BC 矄 ᆠᨨ �ᆠ� 矄ᨨ 矄�ᆠ  ├� �ᆠ �ᆠ�ᨨ 矄  矄ᆠ�泐ᔼ   �矄 ᆠ矄AB BD鼀 ҈鼀矄ᆠ�泐 �  ᨨ �矄 ᆠ ᨨ盐� 犨 �ᆠ  ᨨᆠ├鼀ᨨ矄 ᨨ �ᆠᨨ鼀矄ᨨ矄ᆠᨨ鼀泐 ├�㦨҈鼀⏌矄㡰 ᲼҈黨㜠䰘㝐├矄桌

A

黨

B

C

D

犨ᨨ ᨨᆠ├矄 A   B  ᆠᨨ

ᆠ ᨨᆠ ᨨ 泐 B 矄� � 矄� �錐 矄� � 矄矄矄 ᨨ  �ᆠ�ᨨ 矄矄 C 盐泐矄矄 ᨨ犨 �   ��盐 ᨨᆠ├B A 矄� 矄ᨨ  ᨨ� ᨨ ᨨ 矄盐 ᆠᨨ 矄�ᨨ 泐ᨨᆠ├ C  ᨨᆠ├A矄� 矄ᨨ �  �ᆠ 矄� ᨨ  C ᨨ 犨�  矄鼀盐 � ᨨ鼀矄 

ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨  矄盐 ᆠ矄ᨨ ᨨᆠ├矄 �矄 ᨨᆠᆠᨨ 矄 ᨨ  矄� ��矄҈黨 犨ᨨ 矄⏌鼀ᔼ

鼀矄矄ᨨ ᨨᆠ├A�矄⧤�ᆠᆠ盐 鼀矄矄ᨨ ᨨᆠ├B   �泐矄ᨨ �  矄� � ᲼҈黨㜠�㝐├矄桌 D A 

G

F E C 㡰 㡰 ᔼ   ��盐矄 㡰  㡰ACDG GF �  � ᆠ�   矄BC㦨EF㦨x AB㦨DE㦨y꾀矄鼀ᨨᆠ├ᨨ 鼀矄矄 M�矄矄  ᨨ鼀 ᨨ� Aᔼ矄� 矄 ᨨ犨  AC  ᆠ 矄C犨� 矄 Vc 矄鼀 ᨨᆠ├ �矄矄 ᨨ鼀矄 ᨨ鼀 ᨨ� Dᔼ矄� 矄 ᨨ犨 DGF ᆠ 矄   ᨨ�  F 犨�  矄  VF  ᆠᨨ �ᆠ� 矄 ᨨ  ├� �ᆠ �ᆠ�ᨨ 矄犨  ᨨᆠ├ ᨨ  矄盐 ᆠAC DGFm ᲼҈黨桌 ᔴᆠ盐VC VF ҈ ␔  �矄 ᨨ犨 盐 鼀� �盐 ᨨ �矄鼀ᨨ鼀 盐鼀 ᆠ矄矄      � ᆠ矄矄 ᨨ矄  �矄 �ᨨ   ᆠᨨ 矄�ᨨ ᨨ 鼀ᨨ鼀 盐鼀� ᆠ�䁸 ᲼҈黨䰘黨桌  꾀矄� �ᨨ  ᨨᆠᆠᨨ 矄 k�矄ᆠ盐� ᨨ ⼄盐矄 ␔ �矄 ᨨᆠᆠᨨ 矄 ᨨ ᆠ 䁸 ᲼҈黨䰘桌  꾀盐�矄 �  ᨨ鼀� ᔼ  � ᆠᨨ�矄 泐 鼀�  犨   ├� �ᆠ �泐ᨨ  � �矄�  ⼄盐 ᨨ矄矄   ᨨ  盐 ᲼҈黨䰘桌 B

Topic-3 : Power

҈

S

ᆠᨨ矄ᨨ ҈㦨䰘␔�㦨҈鼀矄㡰᲼㝐� 䰘 ᔼ桌 㡰 ҈䰘鼀矄҈ 㡰 ҈黨鼀矄҈ ҈ ᆠ㡰 ҈�鼀矄 㡰 鼀矄҈ 꾀�ᆠᨨ 鼀矄矄㝐�矄鼀ᨨ� �� ᆠ�ᆠᨨ  �   �盐矄 � 矄盐ᆠ 犨泐 �矄ᆠ �ᆠᆠ�ᨨ �鼀�矄 �� 泐  犨  �矄ᆠᨨ 矄  ᨨ犨 � ᨨ �ᆠ泐  ᨨᆠᆠ� �ᨨ ��矄 ᲼㝐� 졠 � 꾀�҈҈桌

S

҈ 㝐   㡰 㝐    ᆠ㡰 㝐   㡰 㝐   꾀ᆠᨨ 犨�� ␔�矄ᨨ  � ᆠ�  ᨨ  �矄矄泐҈ 鼀ᨨ �矄 ᆠᨨ ҈⧤鼀 �矄ᆠᨨ 矄  �ᆠ�ᨨ 

MCQs with One Correct Answer

1

꾀�ᆠ�矄鼀ᨨ� �盐 � �ᆠ�ᨨ 泐ᨨ  ᨨ� ᨨ   盐   ᆠ�ᨨ ᨨ  ᆠᨨ 矄 ᨨ犨 矄盐泐� � �泐 矄ᨨ盐ᆠ  �矄ᆠ鼀  s㡰㜠�鼀 t㡰�   矄ᆠ�矄  鼀ᨨ�ᨨ ᨨ  �ᆠ�矄 � 矄 犨 矄ᆠ 鼀�ᆠ泐   ᨨᨨ矄ᆠ㡰 ᲼㝐� 和 ᔼᔼ㡰桌 S



㡰

㡰

㡰 t

t

S



␔ ᨨ  ᆠ␔ �鼀ᨨ� �盐 �ᨨ  ᨨ   矄 ᨨ ҈鼀矄҈ ᆠ  矄ᨨ犨. ᔼ �  矄ᨨ犨

ᨨᆠ ᆠ㡰

㡰 t



t

꾀ᆠ�ᆠ鼀ᨨᨨ� 矄 ᨨ � �鼀 �鼀盐鼀 ᨨᨨ ᆠᆠ�泐ᨨ ├�ᔼ   �ᆠ�ᨨ  ᨨᆠᨨ   ᨨ�矄 矄 ᨨ  ᨨ 盐ᨨ �矄

 犨 �鼀ᨨ� � ᨨ犨 �矄 v  盐ᨨ v �矄  ᲼㝐� 졠 � 꾀�黨҈桌 㡰 鼀矄҈ 㡰 �鼀矄҈ ᆠ㡰 ҈�鼀矄҈ 㡰 ҈鼀矄҈

WWW.JEEBOOKS.IN

EBD_8341 P-38

�



䰘



Physics

꾀犨� 㜠ᨨ犨 � ᨨᆠᨨ 矄犨�  �泐� ᨨᆠ�ᆠ  �泐꾀矄矄盐鼀  � ᨨᆠᨨ 矄 �   ᆠ�ᨨ

ᨨ  犨�  �泐� ᆠ 泐�矄 矄� ᨨᆠ�ᆠ  �泐 ᨨ犨� 矄 n ᆠ�ᆠᨨ犨ᨨ盐盐犨� 鼀ᨨ矄�├泐ᨨᨨ�ᨨ ᨨ ᲼㝐� 졠 � 꾀��҈桌 㡰 n  㡰 n  ᆠ㡰 n 㡰 n 꾀䰘├�鼀 矄�ᆠ泐� ᨨ � ᨨ鼀ᆠᨨ盐ᆠ � � ᨨ矄��ᨨ  ᨨ├  鼀 盐矄 矄 �ᨨ盐 犨� ᆠᨨ 矄  ᨨᆠFᨨ�矄 �鼀矄  ᆠ ᨨ ��泐 �矄矄泐�鼀 ᨨ 矄꾀   ᆠ��矄矄泐  ᨨ ҈鼀 鼀 �鼀盐鼀ᨨ犨 � 泐 鼀盐矄ᆠ矄 �矄 ├�㦨҈鼀矄㡰 ᲼㝐� 졠 � 꾀�҈桌 㡰 맔҈␔矄 矄 㡰 맔҈␔矄├ᨨ ᆠ㡰 맔҈␔矄 矄 㡰 맔҈␔矄├ᨨ 꾀 犨� 㜠ᨨ犨  � ᨨ ᆠᨨ 矄 犨�   �泐 � ᨨ ᆠ�ᆠ  �泐꾀矄矄盐鼀   � ᨨ ᆠᨨ 矄 �   ᆠ�ᨨ ᨨ  犨�  �泐� ᆠ 泐�矄 矄 � ᨨᆠ�ᆠ �泐 ᨨ犨� 矄 v ᆠ�ᆠᨨ犨 ᨨ盐盐犨�ᨨᨨ�ᨨ ᨨ ᲼和桌 㡰 v 㡰 v  ᆠ㡰 v  㡰 v  꾀�ᆠᨨ 鼀矄矄鼀�矄鼀ᨨ� �� ᆠ�ᆠ盐 ᨨ ᆠᨨ 矄   �盐矄r矄盐ᆠ  �矄ᆠ �ᆠᆠ�ᨨ ac�矄泐� � 犨� �鼀t矄ac㦨krt犨 k�矄ᆠᨨ 矄  ᨨ犨 � ᨨ �ᆠ矄泐  ᨨᆠᆠ� �ᨨ ��矄 ᲼҈黨黨㜠҈㝐├桌

㡰 mkrt p mk  r  t   � mk r t 㡰 㡰 ᨨ ᆠ㡰  꾀 ᨨ 泐 �矄 鼀ᨨ  ᨨ �  矄��  �  泐 鼀ᆠ �  �� � ᆠᨨ 矄  ᨨ犨  �矄 ᆠ 鼀ᨨ  泐  ᨨ 泐� �鼀t�矄ᨨᨨ�ᨨ ᨨ ᲼҈黨㜠㝐├矄桌 㡰 t ҈⏌ 㡰 t ⏌ ᆠ㡰 t ⏌ 㡰 t  ᔼ 鼀ᆠ � �矄盐�ᆠ 犨� ᨨ� ᲼҈黨桌 㡰  鼀ᆠ  �ᆠ  �ᨨ  鼀ᆠ � � ᆠ矄矄 㡰  鼀ᆠ  �ᆠ �ᆠ� ᆠ泐ᨨ  鼀ᆠ � � ᆠ矄矄 ᆠ㡰 ᨨ  �矄 鼀ᆠ  �ᆠ   �    �ᆠ� ᆠ泐 � ᆠ矄 㡰 �矄 �ᆠ� ᆠ泐� ᆠ矄矄盐�矄鼀ᆠ  �ᆠ  � ᆠ矄矄

㡰

黨

҈

2

Integer Value Answer

҈҈ 꾀�ᆠᨨ 鼀矄矄├��矄鼀ᨨ� �� ᨨ  �鼀 矄�ᨨ 盐   ᨨᆠ  �矄ᆠᨨ 矄 ᨨ犨�␔ᨨ �ᆠ ᔼ  � ��矄  � 鼀矄҈㡰ᨨ  �ᆠ�矄 ᨨ  矄  � 鼀矄҈㡰 �矄�矄 ᲼꾀 ҈桌 3

Numeric Answer

҈ 꾀ᨨ 泐ᨨ 鼀矄矄├��矄 � 泐  ��  �� � ᆠᨨ 矄  ᨨ犨 ᨨ ҈ ⏌矄   ᨨ 泐 矄矄  ᨨ鼀 矄  鼀ᨨ矄� 矄�� � 꾀 黨矄ᆠᨨ 矄 ᨨ 泐 矄 鼀ᨨ  �矄 ᆠ � 鼀㡰힘힘힘힘힘힘 ᲼㝐� �和 ᔼᔼ㡰桌

Topic-4 : Collisions 1 ҈



MCQs with One Correct Answer

�ᆠ꾀ᨨ 鼀矄矄鼀҈鼀ᨨ� �犨� ᨨᆠ�泐 �$ + $ 㡰 鼀矄-҈ ᆠᨨ� 矄犨�  ᨨ �ᆠᨨ 鼀矄矄鼀犨 �ᆠ �矄矄 r r � ��泐 V҈   V  ᨨᆠ��矄ᨨ �ᆠ矄꾀  ᆠᨨ�矄�ᨨ 矄ᆠ�泐ᔼ 鼀҈㦨鼀  ᆠᨨ�矄�ᨨ

r r r V҈ = $� +  $ 㡰 鼀矄 -҈   �犨  V҈   V �矄



᲼㝐� 和 ᔼᔼ㡰桌 㡰 ҈�º 㡰 º ᆠ㡰 �º 㡰 ҈�º ᨨᆠ├矄ᨨ 鼀矄矄矄mmm m � � � ᨨ

 �ᆠ�ᨨ 矄矄 ᨨᨨ꾀 ᨨ ᨨᆠ├ᨨ 鼀矄矄m鼀ᨨ� �犨� 矄 vᨨ � 矄鼀�  矄 ��盐㡰ᆠᨨ� 矄犨� 鼀矄矄 m�  ᆠ泐� 矄�ᆠ鼀

꾀 矄盐矄⼄盐 ᆠᨨ�矄�ᨨ 矄 矄ᨨ ᆠ泐� 矄�ᆠ泐 �鼀 矄ᨨᆠ├ᨨ 鼀矄矄m矄矄鼀ᨨ� � ᨨ �泐ᨨ矄矄�矄p奠ᨨ   ᨨ���  �泐盐ᨨ �p�矄ᆠᨨ矄ᨨ [4 Sep.2020 (I)] v

m

㡰 䰘䰘

m

m

㡰 黨

m

ᆠ㡰 䰘

m

㡰 䰘



�

꾀ᨨᆠ├ᨨ 鼀矄矄҈黨├��矄矄  �ᨨ ᨨ �� ҈鼀꾀盐ᨨ 鼀矄矄҈├�ᆠᨨ� 矄犨�  ᨨᆠ├  矄�ᆠ├矄ᨨ�ᔼ  ᨨᆠ�泐ᨨ  盐�矄鼀⏌矄�   ᨨ� ᨨ  �ᆠ�ᨨ 盐矄 ᨨ ᆠᨨ�矄�ᨨ    ├� �ᆠ  �泐盐矄 ᨨ ᆠᨨ鼀�  矄泐矄鼀矄�├矄  ᨨᨨ �矄᲼ ├g㦨҈鼀⏌矄꾀矄矄盐鼀 �矄 ᨨᨨ�ᨨ 鼀ᨨ�ᨨ

 ᨨ矄矄矄ᨨ  �泐  ᆠᨨ�矄�ᨨ �矄 ����桌 ᲼㝐� 和 ᔼᔼ㡰桌 㡰  㡰 ҈ ᆠ㡰 ҈黨 㡰  꾀�ᆠᨨ 鼀矄矄m犨�  � ��ᨨᆠ�泐 u �ˆ ᆠᨨ� 矄  ᆠ泐矄�ᆠ泐犨� 鼀矄矄鼀矄ᔼ鼀ᨨ矄犨� ᨨᆠ�泐 v ˆ  ᆠᨨ�矄�ᨨ   v�矄�� 泐 [㝐� 2 Sep. 2020 (I)] u  㡰 v = u 㡰 v =   u ҈ u ᆠ㡰 v = 㡰 v =  

犨ᨨ �ᆠ矄 ᨨ  ⼄盐 鼀矄矄 m  矄ᆠ� � �� æ �ˆ + ˆ ö ᨨᆠ��矄 u�ˆ    u ç  ÷  泐ᆠᨨ� ᆠᨨ鼀泐 è ø � 矄�ᆠ泐  �泐ᨨ矄�  ᨨᆠ矄矄�矄 ᲼㝐� 黨 ᔼ桌 ҈ ҈ 㡰  鼀盐 㡰 鼀盐  

WWW.JEEBOOKS.IN

P-39

Work, Energy and Power

  鼀盐 㡰 鼀盐  

犨ᨨ�ᆠ矄ᨨ 鼀矄矄矄㝐 㝐鼀ᨨ� �矄矄 ᨨ犨  犨� 矄 矄ᨨ ҈鼀⏌矄 �鼀⏌矄ᆠᨨ� 矄�ᆠ泐  ᨨ��� 꾀  ᆠᨨ�矄�ᨨ  泐鼀ᨨᨨ � � �ᆠ �ᆠ�ᨨ 矄犨� 矄 矄҈ 矄ᆠ�泐 盐矄 ᨨ ҈  泐 ᲼㝐� ҈꾀�҈黨ᔼ桌

ᆠ㡰



䰘

㡰 �鼀⏌矄 鼀⏌矄 㡰 鼀⏌矄 鼀⏌矄 ᆠ㡰 �鼀⏌矄 鼀⏌矄 㡰 鼀⏌矄 ҈鼀⏌矄 꾀ᨨ 泐ᨨ 鼀矄矄鼀҈鼀ᨨ� �犨�  盐 ├ ᨨ犨 ᨨᆠ�泐ᨨ v҈ �ˆ 盐 �ᨨ矄ᆠᨨ� ᆠᨨ�矄�ᨨ 犨� ᨨ 泐ᨨ 鼀矄矄 m鼀ᨨ� �犨� ᨨᆠ�泐v �ˆ 꾀 ᆠᨨ�矄�ᨨ m҈ m 鼀ᨨ犨� ᨨᆠ��矄ᨨ v �ˆ  v �ˆ 矄ᆠ�泐 ᔼ m㦨�鼀҈ v㦨�v҈  v҈�矄 ᲼㝐� 꾀�҈黨ᔼᔼ桌 v v 㡰 vv ᆠ㡰 v 㡰 v졔v   꾀  㜠�ᆠᨨ 鼀矄矄鼀矄盐 矄҈㜠 �鼀 矄�ᨨ 矄�ᆠ ᆠᨨ�矄�ᨨ 犨�   盐ᆠ盐矄矄ᨨ 盐 ├ ᨨ犨 鼀矄矄 ᔼ�矄 矄ᆠ  �ᆠ泐ᆠ├犨 矄 ᨨ矄� � 奠 ᨨ �矄 � �� ├� �ᆠ �泐 鼀矄矄ᨨ   盐ᆠ盐矄�矄 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 鼀 㡰 �鼀 ᆠ㡰 ҈�鼀 㡰 鼀 꾀�ᆠ ᨨ 犨ᨨᨨ  ᨨ 鼀矄矄 ├� �矄 ᨨ  ᨨ鼀   ᨨᨨ ҈鼀 �� 盐� � �꾀 矄鼀�鼀盐 ᨨ 鼀矄矄├��矄 � �ᆠ泐盐犨 犨� ᨨᆠ�泐 ҈鼀矄҈ ᨨ鼀 �ᨨ盐  盐�矄鼀  �

  犨ᨨᨨ      鼀 �鼀盐鼀 ��  ᨨ 犨 �ᆠ    ᆠᨨ鼀�   矄泐矄鼀 ᆠ 矄 ᨨ   ᨨ ᨨ    盐� � �  ᨨ � �ᨨ犨�矄 �㦨҈鼀矄㡰 ᲼㝐� ҈   ҈黨 ᔼ桌 㡰 鼀 㡰 鼀 ᆠ㡰 鼀 㡰 ҈鼀

ᨨᆠ├꾀 ᔴ泐� �ᨨ 矄鼀ᨨᨨ  ᨨ� ᨨ  矄盐 ᆠ矄矄 ᨨ犨 �   ��盐꾀  ⼄盐鼀矄矄矄 鼀犨 �ᔴ 矄鼀矄矄㝐ᨨᆠ├꾀�矄��  � �矄 v ᨨ犨 矄  盐 ᨨ 犨 �ᆠ  � ᆠᨨ� 矄 犨�    ᆠ泐 � 矄�ᆠ泐 ᆠᨨ鼀�  鼀矄矄ᆠᨨ� 矄犨� ᔴ矄ᨨ �  ᆠ泐� 矄�ᆠ泐  ᨨ  � ��├� �ᆠ �泐�矄  ᨨ矄� 犨 ᨨᨨᆠ矄矄␔ �矄盐ᨨ 㝐⏌鼀䁸

㡰 v 

黨

҈

꾀 鼀 㡰 �

㡰 

᲼Main黨 ҈黨ᔼ桌 ᔴ 㝐

 鼀 ᆠ㡰 





҈҈ ᔼ ᆠᨨ� ᆠᨨ�矄�ᨨ �ᆠ犨�  � ��矄  n 矄�├矄矄�ᨨ 泐�ᆠᨨ  矄鼀鼀矄矄ᔼ   �  ᨨ├� �ᆠ �泐�矄�奠�   ᨨ��� ├� �ᆠ  �泐 鼀� �盐 ᨨ  �ᨨᆠ�泐犨   犨ᨨ�ᆠ矄 ᆠᨨ�矄�ᨨ �矄 ᲼㝐� ҈桌

n n n 㡰 n ᆠ㡰  㡰    ҈ 鼀矄矄ᨨ  泐 ᨨ� 鼀ᨨᆠ盐�矄맔҈䰘├�ᔼ ҈ 泐 ᨨ� 鼀ᨨᆠ盐矄矄�├矄ᆠᨨ  �  犨ᨨ   ᆠ鼀     � ᨨ  �  ᨨ  ᨨ鼀   ᨨ盐 矄�ᆠ泐犨� 矄 ᨨ ҈鼀⏌矄   矄矄盐ᨨ

 犨�矄 泐 ᲼㝐� ҈桌 㡰 �맔҈⏌鼀 㡰 䰘맔҈⏌鼀 ᆠ㡰 �맔҈⏌鼀 㡰 䰘맔҈⏌鼀 ҈ ᔼ�矄 ᨨ盐  �  盐ᨨ 矄盐 矄  矄�ᆠᆠᨨ�  ᆠᨨ�矄�ᨨ 犨�  盐�盐鼀矄 ᆠ�ᨨ ᨨ矄矄ᨨ �矄 �泐 is p 錐犨 � ᨨ�矄矄�鼀�ᆠᨨ�矄�ᨨ 犨� ᆠᨨ  盐ᆠ盐矄 矄 ᆠ�ᨨ ᨨ矄矄ᨨ  �泐�矄ᆠ 盐矄ᨨ   ᆠ 矄ᆠ�泐 ᲼㝐� ҈桌 㡰

㡰 ( ×黨 ×) 㡰 ( × ×黨 ) ᆠ㡰 (0, 0) 㡰 (0, 1) ҈ 꾀 盐ᨨ  鼀ᨨ� � 犨�   矄  ἘἘ 鼀├矄    ᨨ

ᆠᨨ�矄�ᨨ 犨� 矄�ᨨ 泐 泐 ᨨ� ᨨ鼀� �ᨨ盐 矄

鼀� �鼀盐鼀├� �ᆠ �泐ᨨ   盐ᨨ  ᨨ犨 �ᆠ � 矄�ᆠᆠᨨ�矄�ᨨ 犨�├ᆠ�矄 ᲼㝐� 졠 � 꾀�҈҈桌 㡰  㡰 ҈ ᆠ㡰 ҈҈ 㡰 ҈ ҈� 꾀�ᆠᨨ 鼀矄矄鼀鼀ᨨ� ��    �ᆠ�ᨨ 犨� 矄 v�矄 �泐 ᨨ �ᆠᨨ 鼀矄矄m鼀ᨨ� ��  y �ᆠ�ᨨ 犨� 矄 ᔼ  ᆠᨨ�矄�ᨨ �矄 ᆠ泐� 矄�ᆠ  ᆠ �ᨨ矄矄�   �泐 盐� � ᆠᨨ�矄�ᨨ �矄 ᆠᨨ矄ᨨ  ᲼㝐� ҈�桌 㡰 �奠 㡰 奠 ᆠ㡰 奠 㡰 �奠 ҈ 鼀矄矄矄鼀鼀 鼀鼀ᨨ� ��  㜠泐 犨� 矄 盐盐 盐矄ᆠ�泐矄矄 ᨨ犨 �  ��盐    鼀矄矄矄 ᆠᨨ�     矄鼀 ᨨ�      矄�ᆠ├ ᨨ�  ᨨᆠ�泐ᨨ 矄盐� �鼀矄矄犨� ᲼㝐� 졠 � 꾀�҈҈桌 泐 鼀盐  鼀盐







鼀盐

(

)

(

)

盐 ˆ 盐 ˆ � + ˆ � - ˆ 㡰 㡰 ҈ ҈ 盐 ˆ 盐 ˆ -� + ˆ -� - ˆ ᆠ㡰 㡰 ҈ ҈ ҈䰘 꾀

�矄�矄 ᨨ ᨨ  ᨨ� ᨨ 矄鼀ᨨᨨ 矄盐 ᆠᔼ ᨨ盐 ᆠ矄 ᆠ├ ᨨ�矄 ᨨ���  ᨨ矄��ᨨ    �� �   矄盐 ᆠ  ᨨᆠ ᨨ     盐� �   ᆠᨨ�矄�ᨨ  �矄 ᨨᨨ�ᨨ  ᨨ    �  ᨨ ᆠᨨ鼀矄矄�ᨨ  ᨨ    ␔ �ᆠ  ᨨ  ᨨ    ᨨᨨ犨� � 矄├ᆠ 矄 矄ᆠ�矄   ��ᨨ  ᨨ  �矄 ├� �ᆠ  �泐 K 犨�  �鼀 t 鼀ᨨ矄 ᨨ�泐䁸  ��盐ᨨ 泐�盐矄�  ᨨᨨ  矄ᆠ ᲼꾀 ҈桌

(

)

(

)

WWW.JEEBOOKS.IN

EBD_8341 P-40

Physics K

K

㡰

2

㡰 t

t

K

K

ᆠ㡰

㡰 t

t

҈ 꾀�ᆠᨨ 鼀矄矄m �矄ᨨᆠ  ᨨ鼀 �ᨨ盐 犨� 

� ��矄 u  �a犨�   ᨨ� ᨨ 꾀  �� 矄ᨨ� ᨨ �矄ᆠᨨ泐�鼀├矄ᆠᨨ鼀泐� 矄�ᆠ ᆠᨨ�矄�ᨨ 犨�  ᨨ �  �ᆠ�ᆠ犨 �ᆠ 犨矄 ᨨ犨

�ᆠ泐盐犨  ᨨ鼀 �ᨨ盐 犨�  矄鼀� �� 矄 盐  �  ᆠᨨ鼀ᨨ矄�矄泐矄鼀鼀├矄犨�   ᨨ� ᨨ �鼀鼀 �泐  ᆠᨨ�矄�ᨨ �矄 ᲼꾀 ҈桌 p p p p -a 㡰 + a ᆠ㡰 㡰     꾀ᨨ 鼀矄矄├�矄矄ᨨ �ᆠᨨ矄ᨨ  �� �鼀꾀 盐ᨨ 鼀矄矄҈├�� �犨� ᨨᆠ�泐鼀⏌矄�  ᨨ� ᨨ  �ᆠ�ᨨ  �矄 ᆠ ᨨ  꾀   ᆠᨨ�矄�ᨨ   盐�   泐  �矄 �ᨨ盐  �矄 ᆠᨨ 鼀  盐 �矄 ᆠᨨ ҈鼀 ᨨ鼀  ᨨᨨᨨ  ᨨ矄 ᨨᆠ�泐 ᨨ  盐�矄 ᲼҈҈桌

㡰 ҈黨



㡰 �鼀⏌矄 㡰 �  鼀⏌矄 ᆠ㡰 鼀⏌矄 㡰 �鼀⏌矄

犨ᨨ 矄鼀 �ᆠ矄 ᨨ  ⼄盐 鼀矄矄矄 矄 鼀ᨨ� � �

ᨨᨨ矄� �ᆠ�ᨨ 矄 ᨨ鼀ᨨ� A�  ᨨ� ᨨ ᆠ�ᆠ盐 ᨨ� � � �ᨨᆠ��矄v  v矄ᆠ�泐 矄矄 ᨨ犨 �   ��盐犨 ᆠᨨ�矄�ᨨ 矄 �ᆠ矄 鼀ᨨ犨� ᆠᨨ 矄 矄 矄꾀 鼀├� � ᨨ犨鼀 泐矄�ᆠ ᆠᨨ�矄�ᨨ 矄ᨨ    A 矄犨ᨨ�ᆠ矄犨� �� ᆠ  ᨨ� A䁸 ᲼黨桌 v

A

v

Integer Value Answer

 ᨨᆠ矄A, B  C├� 矄�� � ᨨ  �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ 矄 鼀矄矄矄m, 2m  m, 矄ᆠ�泐 ᨨᆠA 鼀ᨨ矄ᨨ犨 矄B犨�  矄 黨鼀⏌矄 鼀├矄 矄�ᆠᆠᨨ�矄�ᨨ 犨� �   B鼀├矄ᆠᨨ鼀泐� 矄�ᆠᆠᨨ�矄�ᨨ 犨� C.꾀 鼀ᨨ�ᨨ 矄ᨨᆠᆠ盐ᨨ  矄鼀矄�� �  �   �  矄  � 鼀⏌矄㡰ᨨ  ᨨᆠᔴ ᲼黨桌 m

m

m







 꾀ᨨᨨ 鼀矄矄 m, 矄盐矄  泐矄� �ᨨ  �  l1, �矄 �� 鼀� �鼀盐鼀ᨨᆠ�泐⼄盐� ᨨᆠᨨ鼀 盐ᆠ�ᆠ�

 �ᆠ 꾀  �� 矄ᨨ� �ᆠᨨ� 矄矄�ᆠ泐 犨�  ᨨ ᨨᨨ 鼀矄矄m 矄盐矄  泐矄� �ᨨ  � l2, 犨 �ᆠ �矄� ��泐矄ᨨ  矄� �矄鼀矄矄㜠矄矄  �   矄�ᔼ  矄ᆠᨨ ᨨ ᆠᨨ�矄�ᨨ ᆠ⼄盐�矄  鼀� �鼀盐鼀矄 ⼄盐� ᨨᆠᨨ鼀 盐ᆠ�ᆠ�   l �ᆠ  �ᨨ ҈ �矄 ᲼꾀 ҈桌 l 3

Numeric Answer

 犨ᨨᨨ �矄ᨨ  矄鼀鼀矄矄鼀ᨨ� �犨�  矄鼀 矄 盐�  �   �ᆠ�ᨨ 矄�   泐  ᆠᨨ鼀泐� 矄�ᆠᆠᨨ�矄�ᨨ  鼀ᨨᨨ�    犨�  � 矄 犨 �ᆠ �矄  ᨨ  �� ��矄    �犨  � ��ᨨᆠ��矄ᨨ  犨ᨨᨨ �矄 �

᲼㝐� 和 ᔼ㡰桌 �㡰�矄힘힘힘힘힘힘 � 꾀�ᆠᨨ 鼀矄矄m�矄鼀ᨨ� �ᨨ � x㜠 �矄犨� � �� ᨨᆠ�泐 u�ˆ ᔼᆠᨨ� 矄矄�ᆠ泐犨� �ᆠᨨ 鼀矄矄 ҈鼀矄   鼀ᨨ矄犨�   �矄� ��├� �ᆠ  �泐 矄 ��盐㡰ᔼ  矄� q҈ = n 矄� q   盐ᨨ n �矄 힘힘힘힘힘힘힘힘힘힘힘 [㝐� 2 Sep. 2020 (II)] 鼀 q҈ 鼀 ҈鼀 q u�$ ҈鼀  꾀ᨨ 泐Aᨨ 鼀矄矄m㦨҈├� 矄 � ��ᨨᆠ�泐ᨨ  �ˆ 鼀矄҈ ᔼᆠᨨ� 矄矄�ᆠ泐犨�  ᨨ ᨨ 泐Bᨨ  矄鼀 鼀矄矄 犨 �ᆠ  矄   � �� ᨨᆠ�泐ᨨ  � ˆ 鼀矄҈ 꾀  r ᆠᨨ�矄�ᨨ A鼀ᨨ矄犨� ᨨᆠ�泐v =  �ˆ + ˆ   �泐 x ᨨ B ᆠᨨ�矄�ᨨ �矄犨� 矄 J 盐ᨨ x�矄 ҈ 힘힘힘힘힘힘힘 ᲼㝐�  ᔼ桌

(

҈

㡰  㡰  ᆠ㡰  㡰 ҈

犨ᨨ�ᆠ矄ᨨ 鼀矄矄矄m҈ m� ᨨᆠ�鼀ᨨ�ᨨ

r r ᨨᆠ��矄 v҈   v 矄ᆠ�泐�鼀t㦨 泐 r r ᆠᨨ� �鼀 tᨨ �ᨨᆠ��矄ᆠᨨ鼀 v҈ Ἐ   v Ἐ  �鼀 t ᨨ  犨 � 矄� 鼀ᨨ� � �  �  盐 ᨨ r r r r ᲼҈和桌 ( m҈v҈ Ἐ+ mv Ἐ) - ( m҈v҈ + mv ) �矄 㡰 ᨨ 㡰 ( m҈ + m ) gtᨨ ҈ 㡰  m҈졔m㡰gtᨨ ᆠ㡰 ( m҈ + m ) gtᨨ 

)

䰘 꾀�矄ᨨᆠ  ᨨ鼀 �ᨨ盐   �ᨨ �ᨨ犨�   ᨨ� ᨨ 矄盐 ᆠᔼᆠ 矄鼀 �鼀盐鼀 �� ᨨ ҈ m  盐 矄ᨨ �ᨨ盐 ᨨ  �� � �ᨨ盐  ᨨ   �矄�鼀�ᨨ矄矄  ᨨ �矄├� �ᆠ �泐ᔼ鼀鼀 �泐   ᨨ盐 ᆠ ᨨᆠ�泐ᨨ  鼀├矄  � ᨨ ᨨ犨�   ᨨ� ᨨ 矄盐 ᆠ 鼀 �鼀盐鼀 �� � ᆠ 矄  ᨨ盐 ᆠ� metres�矄힘힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌

WWW.JEEBOOKS.IN

P-41

Work, Energy and Power

6 

MCQs with One or More than One Correct Answer

꾀矄鼀�ᆠᨨ 鼀矄矄m鼀ᨨ� �� 矄�  泐 ᨨᨨ犨  矄�� 盐ᨨ � 盐 �矄盐 �ᨨ矄矄�ᆠ ᆠᨨ�矄�ᨨ 犨ᨨ 矄 盐 矄 ᨨ �ᆠ�ᨨ  ��矄 ᆠᨨ矄 ᨨ  泐 矄盐 ᆠ犨 � ᨨ  �矄 � 犨�  泐鼀ᨨ �矄ᨨ 矄矄 ᨨ犨 �  ��盐 ␔    �矄 ᆠᨨ  �矄ᨨ  ᨨ鼀ᆠᨨ矄  �矄L㦨L  �ᆠ矄 �矄v㦨v �矄ᨨ �矄鼀ᨨ � 犨  dL v 犨 dL�矄  泐ᨨ犨矄 V 矄盐ᆠ   V >mw㡰 � ᆠ  ��     �  ᨨ  矄� � �矄 矄 �� 泐  ᨨ�ᨨ  ᲼㝐� 黨 ᔼᔼ桌

WWW.JEEBOOKS.IN

P-49

System of Particles and Rotational Motion

㡰

 æ mw ö ç ÷  çè k ÷ø

mw 㡰 k

mw mw 㡰 k k 꾀�ᆠᨨ 鼀矄矄m�矄 �  ᨨᨨ  ᨨ �� 矄� � � � ᨨᆠ ᆠᨨ 矄  k   盐 矄ᆠ    �  l  ᨨ  �矄 �   矄泐矄鼀�矄��   �盐矄 w ᨨ盐  �   ᨨ  矄� �矄盐ᆠ  �ᨨ矄�  ᆠ�ᆠ� ��泐 矄ᆠ   矄ᆠ �  矄� � �矄 ᲼㝐�  ᔼ桌

ᆠ㡰



㡰

ml w

㡰



k - mw  





ml w 

ml w k + mw k + mw 꾀矄鼀ᨨᨨ 犨�ᨨ  � p�矄 � ᨨᆠ�ᆠ ├�

�ᆠ 꾀 ᆠ 矄� 矄鼀ᨨᨨ 泐ᨨ  犨� ␔   ᆠ�ᆠ�矄ᨨ� �犨�  �盐矄 wᨨ盐  �ᆠ �鼀꾀矄矄 ᨨ犨 �  ��盐  �矄矄 犨� 矄ᆠᨨ ᆠ�ᆠ盐� �ᨨ矄��ᨨ 矄矄 ᨨ犨 

  盐ᨨ w�矄⼄盐ᨨ᲼㝐� ҈꾀҈黨ᔼᔼ桌

ᆠ㡰 �

ml w k - wm



g g ᆠᨨ矄 q ᆠᨨ矄 q 㡰 l l g g 矄� q ᆠ㡰 㡰 矄� q l l ᔴᨨ ᆠ鼀� 盐�矄鼀 泐鼀� � �ᆠ鼀 矄ᨨ  矄 � ᨨ� �ᆠ泐� �ᆠ 盐鼀ᔼ   盐鼀ᨨ矄ᨨᨨ 矄 � � � 矄鼀� 矄盐ᆠ├ᨨ 犨ᨨ   盐鼀  ᨨ鼀� � �ᨨ � � � 矄 ᨨ矄 ᨨ├ᆠ  鼀 �鼀盐鼀ᨨ�ᨨ 矄 ᨨ   盐鼀� ᨨ盐�ᨨ 矄 鼀� 盐 鼀㡰ᨨ 矄盐ᨨ鼀� � ��矄ᆠᨨ矄ᨨ ├  �盐矄ᨨ   盐鼀ᨨ҈�鼀 �矄 ᨨ ᨨ� ᨨ 㡰 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 䰘 㡰  ᆠ㡰 ҈ 㡰 

犨ᨨ�  �ᆠ �矄ᆠ矄ᨨ 矄鼀 �盐矄Rᨨ� �ᨨ盐  � 矄� ᨨᨨ矄� �ᆠ�ᨨ 矄犨�  矄鼀ᆠᨨ 矄   �盐矄 w  �矄ᆠ矄�  矄鼀 ᨨ� ᨨ   꾀�鼀t㦨 ᨨ� 矄P Q ᆠ� �ᆠ ᨨ 矄 矄 ᨨ犨 �   ��盐 �矄 犨  犨ᨨ ᨨ� 矄P Q�矄vrᔼ ᨨ �鼀�ᨨ  T㡰ᨨ ᨨ�ᨨ ᨨ   �矄ᆠ矄vr 矄 盐 ᆠ�ᨨ ᨨ �鼀�矄矄矄  泐 ᲼҈桌

㡰

黨

㡰

㡰  

g 㡰  g ⏌ r 㡰 r 㡰 �⏌r ᆠ㡰 g 㡰 ⏌  꾀�ᆠ�矄鼀ᨨ� �犨� 盐 � ᨨ鼀矄 � ᆠ�ᆠ盐ᨨ� ᨨ  �盐矄 � ᆠ  ᨨᆠ� 矄泐ᨨᨨ�ᨨ ᨨ  n ᨨ犨ᨨ  ᔼ  �ᨨ ᨨ ᨨ�ᨨ ᨨ  �ᆠ�矄     ᲼㝐� ҈桌 ⏌ 㡰 µ   ᨨ 泐  㡰 µ n ⏌+҈

㡰



䰘

ᆠ㡰 µ +҈㡰⏌ 㡰 µ ⏌ 꾀矄 盐 � ᨨ鼀ᨨ ᨨ 鼀矄矄㝐  �  l �矄�ᨨ ᨨ  矄ᨨ  �ᆠ ᨨ� �ᆠ   矄 ��盐㡰 �矄 ���� �ᆠ�ᨨ  �ᨨ    �矄  �ᆠ泐ᨨ �ᨨ   矄 

 �盐ᆠᆠ�ᨨ ᨨ  ᨨ 犨  �鼀├矄  � ᲼㝐� ҈䰘桌 q 犨�  �ᆠ�矄

ᆠ㡰

㡰 



҈ ᔴᨨ 矄�  �矄ᆠᨨ� ��   ᨨ� ᨨ  犨�  ᆠᨨ 矄  �盐矄 w ᨨ盐�矄ᆠ 졠  �矄ᆠ 矄  矄    ��ᨨ  ᨨ  ᨨ  矄�  ᨨ    �鼀   

盐 矄   ��ᨨ ᨨ  ᨨ 矄� 矄矄 ᨨ犨 �   ��盐 ␔    �矄ᆠ�矄�  ᨨ� �ᨨ 矄矄 ᨨ犨 犨ᨨ矄 P Q矄�鼀盐 ᨨ盐矄泐ᨨᆠ   �ᨨ犨 矄 R ᨨᆠ�泐ᨨ ᨨᆠ�ᨨ �矄�  y㜠z  �矄矄鼀 ᨨᨨ 矄犨� 矄ᆠᨨ  �矄ᆠ꾀矄矄盐鼀  �㡰  泐 ᆠ├ᨨ   �矄ᆠ ᨨ  �矄ᆠ 矄ᆠᨨ鼀 ҈⏌ᨨ�ᨨ  ��㡰 � ��矄矄矄      �矄ᆠ �盐矄   ���㡰w 鼀� 矄ᆠᨨ 矄  ᨨ盐� ᨨ盐  ᲼҈桌

㡰 P 矄�  矄   ��ᨨ  Q�  盐 矄   ��ᨨ  㡰 P 矄�  盐 矄   ��ᨨ  Q�  矄   ��ᨨ  ᆠ㡰 ᨨ P Q �  盐 矄   ��ᨨ  㡰 ᨨ P Q �  矄   ��ᨨ 

WWW.JEEBOOKS.IN

EBD_8341 P-50

Physics

4 ҈҈

Fill in the Blanks

和ᨨ�� S ᨨ矄�   ᨨ� ᨨ    犨�  ᆠᨨ 矄   �盐ᨨᆠ�泐ᨨ ҈ � ⏌矄ᆠᨨ  矄ᨨᨨ �� P 鼀ᨨ矄ᨨ � 犨 �矄 ᆠᨨ 鼀 ᨨᆠ�泐ᨨ  矄ᨨP犨   q 㦨�  矄 ��㡰�矄鼀⏌矄 ᲼҈黨䰘㜠㝐├矄桌

ᨨ犨ᆠᨨ 矄� 矄鼀ᨨᨨ 矄ᨨᨨ � �鼀ᨨ  �矄ᆠᨨ  �盐矄 ᨨ� �ᆠᨨ盐 㜠ᆠᨨᆠ├犨�矄犨� ᆠᨨ 矄  �盐矄 w ᨨ盐�矄�ᆠ �矄 ᨨ盐� �矄ᆠ ␔矄矄�� ᆠᨨᨨ �  矄泐矄鼀犨�  ᨨ���  ᆠ ᨨ   �矄ᆠ  㜠 �矄ᨨ �  矄ᨨ 泐㜠 �矄 w

鼀 ⏌

 �ᆠ盐ᨨ 矄ᨨ   㜠 �矄ᨨ � ᨨ�ᨨ  �矄 ur 犨 㦨犨 ├ˆ 꾀矄鼀ᨨᆠ├ᨨ 鼀矄矄鼀�矄� 泐ᆠ �  矄ᨨ 8

Comprehension Based Questions

矄矄� 꾀 鼀ᨨ   ᆠ �矄ᆠᆠ 犨� 矄ᆠᨨ � � 鼀ᨨ   ᆠ�矄ᆠ  ᨨ 㜠� � 鼀ᨨ   ᆠ꾀 ᆠᨨᨨ � 矄泐矄鼀 �  ᨨ ᆠ�ᆠ盐 �矄ᆠᨨ� �ᨨ盐 �   �矄犨� ᆠᨨ 矄  �盐ᨨᆠ�泐w�矄  鼀ᨨ  ᨨ 㜠 � � 鼀ᨨ   ᆠ �ᨨ 矄 �犨   ᨨᆠ r ᨨ  � ᆠ 泐�ᆠᨨ 鼀矄矄鼀鼀ᨨ� �ᨨ  ᨨ� � r �矄ᆠ   ᨨᆠ �  � ᆠ 泐 �ᆠ�  � � 鼀ᨨ   ᆠ�矄 r r r ur ur r ur ᨨ 㦨 � 졔 鼀  ᨨ  犨 졔 鼀 犨    犨  r 犨   ᨨ �矄 ᨨᆠ�泐ᨨ  �ᆠ�  ᨨ� � 鼀ᨨ r   ᆠ     �矄   ᨨ矄��ᨨ  ᆠᨨ ᨨ    �ᆠ 犨� 矄ᆠᨨ ᆠ ᨨ   �矄ᆠ



㡰 㡰

r



 ⏌ 㡰 ˆ� 㦨 �矄ᆠᨨ 矄�  ᨨ鼀ᨨᨨ 泐ᨨ � 矄ᨨ ҈  �矄 ᆠᨨ  ᨨᆠ├�鼀�矄 ᲼꾀 ҈桌

㡰

犨  㜠犨   졔 

 



ᆠᨨ矄 犨  

㡰

ᆠᨨ矄 犨   ҈  ᆠ�ᨨ ᨨ   �矄ᆠᨨ  ᨨᆠ├�矄᲼꾀 ҈桌 ҈ 鼀犨  犨  㜠  㜠 犨  ˆ 졔 鼀�├ˆ 㡰  ҈ 鼀犨  犨  㜠 㜠犨  ˆ 졔 鼀�├ˆ 㡰  ᆠ㡰 㜠 鼀犨  ᆠᨨ矄犨  ˆ 㜠 鼀�├ˆ 㡰 鼀犨  矄� 矄犨  ˆ 㜠 鼀�├ˆ

ᆠ㡰

犨 

졔  㜠 犨 











Topic-3 : Torque, Couple and Angular Momentum 1 ҈

ᨨ盐O 矄犨� �矄矄矄盐ᨨ  ᆠᨨ�矄�ᨨ 鼀├� �

MCQs with One Correct Answer

angle q ᨨ鼀ᨨ鼀 �泐ᆠᨨ鼀� �ᨨ矄ᔼ  ᨨ  矄 鼀矄矄 M㦨 ├�   �  l㦨 ҈鼀 盐ᨨ q �矄 ᨨ �鼀泐 ├g㦨҈鼀⏌矄㡰 [Main Sep. 03, 2020 (I)]

ᨨ盐ᨨ� 鼀矄矄矄ᆠ ᨨ 鼀矄矄m �   ᆠᨨ 矄 ᨨ 矄⼄盐ᨨ 矄� l 矄⼄盐�矄ᨨ� �犨�  �盐 ⼄盐 ᆠ泐wᨨ盐  �矄矄矄� � ᨨ盐� ᨨ ᨨ   ᆠᨨ 矄 ᨨ    矄⼄盐    ᨨ �矄 ��ᨨ  矄 矄 ᨨ犨 �   ��盐  �盐鼀ᨨ鼀 盐鼀ᨨ  矄⼄盐 ᨨ盐 �矄 �矄�矄 ᲼㝐� 和 ᔼ㡰桌

O M, l q m

m

 �矄

m v

㡰  ᆠ㡰 黨 㡰 鼀lw 

㡰 鼀lw

ᆠ㡰 鼀lw 㡰 鼀lw 꾀ᨨᆠ├ᨨ 鼀矄矄m㦨҈├�矄� 矄犨� ᨨᆠ�泐v㦨鼀⏌矄ᨨ

 �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ ᆠᨨ� 矄犨� 盐 � ᨨ鼀 �ᆠᨨ  矄�ᆠ├矄ᨨ�矄矄 ᨨ犨  ᨨ �矄�ᨨ

㡰 �� 㡰 黨

  A

�

�

䰘�

鼀

҈ B

WWW.JEEBOOKS.IN

P-51

System of Particles and Rotational Motion

4.

Shown in the figure is rigid and uniform one meter long rod AB held in horizontal position by two strings tied to its ends and attached to the ceiling. The rod is of mass 'm' and has another weight of mass 2 m hung at a distance of 75 cm from A. The tension in the string at A is : [Main Sep. 02, 2020 (I)] (a) 0.5 mg (b) 2 mg (c) 0.75 mg (d) 1 mg A uniform cylinder of mass M and radius R is to be pulled over a step of height a (a < R) by applying a force F at its centre 'O' perpendicular to the plane through the axes of the cylinder on the edge of the step (see figure). The minimum value of F required is : [Main Sep. 02, 2020 (I)] F

O

æ R-aö (a) Mg 1 - ç ÷ è R ø

2

R

a 2

æ R ö (b) Mg ç ÷ -1 è R-aø

a a2 (d) Mg 1 - 2 R R Consider a uniform rod of mass M = 4m and length l pivoted about its centre. A mass m moving with velocity v making p angle q = to the rod’s long axis collides with one end of 4 the rod and sticks to it. The angular speed of the rod-mass system just after the collision is: [Main 8 Jan. 2020 I]

(c) Mg

5.

6.

7.

3 v (b) 7 2l

4v 3 2v (d) 7l 7 l A particle of mass m is moving along a trajectory given by x = x0 + a cos w1t y = y0 + b cos w2 t The torque, acting on the particle about the origin, at t = 0 is: [Main 10 Apr. 2019 I] 2$ 2$ (a) m ( - x0 b + y0 a ) w1 k (b) +my0 aw1 k 2 2 $ (c) zero (d) -m( x0 bw2 - y0 aw1 )k The time dependence of the position of a particle of mass r m = 2 is given by r (t ) = 2 t i$ - 3t 2 $j . Its angular momentum, with respect to the origin, at time t = 2 is : [Main 10 Apr. 2019 II] $ $ (a) 48 i + j (b) 36k$

(a)

(

(

)

(c) -34 k$ - i$ 8.

)

3v 7l

9.

(a) 4.0×10–6 Nm (b) 1.6×10–5 Nm (c) 7.9×10–6 Nm (d) 2.0×10–5 Nm A rectangular solid box of length 0.3 m is held horizontally, with one of its sides on the edge of a platform of height 5m. When released, it slips off the table in a very short time t = 0.01 s, remaining essentially horizontal. The angle by which it would rotate when it hits the ground will be (in radians) close to : [Main 8 Apr. 2019 II]

(a) 0.5 (b) 0.3 (c) 0.02 (d) 0.28 10. A particle of mass 20 g is released with an initial velocity 5 m/s along the curve from the point A, as shown in the figure. The point A is at height h from point B. The particle slides along the frictionless surface. When the particle reaches point B, its angular momentum about O will be : [Main 12 Jan. 2019 II] (Take g = 10 m/s2) O

(c)

(d) -48k$ A metal coin of mass 5 g and radius 1 cm is fixed to a thin stick AB of negligible mass as shown in the figure The system is initially at rest. The constant torque, that will make the system rotate about AB at 25 rotations per second in 5s, is close to : [Main 10 Apr. 2019 II]

a = 10 m A h = 10 m

B (a) 2 kg-m2/s

(b) 8 kg-m2/s

(c) 6 kg-m2/s

(d) 3 kg-m2/s uur uur 11. A slab is subjected to two forces F1 and F2 of same uur magnitude F as shown in the figure. Force F2 is in XYplane while force F1 acts along z-axis at the point r r 2i + 3 j . The moment of these forces about point O will

(

)

be :

[Main 11 Jan. 2019 I] Z F1 O

F2

y

30º 4m 6m x

WWW.JEEBOOKS.IN

EBD_8341 P-52

Physics

㡰 ᆠ㡰 ҈

( $� -  $ + k$ ) ( $� +  $  k$ )

㡰 㡰

( $� -  $  k$ ) ( $� +  $ + k$ )

犨� 矄 矄 矄ᆠ�泐 鼀矄矄矄矄�ᆠ├ᨨ     ᆠᨨ�矄�ᨨ  �矄 ᆠ   矄ᆠ�泐   ᨨ鼀 ᆠ ᨨ  ᔼ  矄矄ᨨ� �ᨨ盐 �矄ᆠ ᨨ 鼀矄矄矄矄盐ᨨ ᆠᨨ�矄�ᨨ   �盐矄 ᨨ  犨� ᲼㝐� 졠 � 꾀�҈�҈桌

鼀� �盐 ᨨ ᨨ⼄盐ᨨ �ᆠᨨ 鼀矄矄҈├��矄� 鼀ᨨ盐 ᨨ��� ᔼ   ᨨᆠᆠ� �ᨨ ��矄҈   �矄 ᆠᨨ  �ᆠ ᨨ鼀 ᨨ��� �矄�鼀  � 犨   ᨨᆠ  ᨨ矄��ᨨ ᆠᨨ�矄 �  � 矄㡰 ᲼㝐� ҈҈ ҈黨ᔼᔼ桌

p p p p 㡰 ᆠ㡰 㡰     ҈ ᨨ 鼀ᨨ㜠ᆠ   ᨨᨨ  ᆠ � � 鼀ᆠ �  矄矄矄  ᆠ�ᆠ盐 鼀ᨨ ᨨ  �盐矄  �ᆠ泐 ᨨ犨  犨�   ᨨ ᨨᆠ    ᨨ矄 � 犨�   ᆠᨨ 矄   �盐 矄 ᨨ盐 �矄  �矄 ᔼ    ᨨᆠ  �矄 �矄�盐  盐 � ᨨ鼀泐 ᨨ  鼀ᨨ  � ᆠᨨ �ᆠ�  ᨨ  �ᆠ�ᨨ  犨    鼀ᨨ     ᨨᨨ �矄 m   ᨨ⼄盐 �  泐   鼀ᆠ � ᨨ  鼀ᨨ�矄 ᲼㝐� ҈ ҈黨ᔼ桌 㡰 m ⏌ 㡰 m ⏌

⏌

v

㡰

 μ m  꾀��� 鼀矄矄矄矄ᨨ ᨨ  � l 矄犨ᨨ鼀矄矄矄ᆠ  ᆠ  矄矄 ᨨ犨 �   ��盐 ᨨ �矄�ᨨ  ᨨ� ᨨ   ᨨ� ᨨ  �矄 矄 ��盐㡰␔  矄 ᨨ鼀� �� ᨨ� ᨨ ᨨ矄��ᨨ �矄� 矄  ᨨ盐矄 �盐 ᆠᆠ�ᨨ 犨� ᲼㝐� ҈ ҈黨ᔼᔼ桌 l l

ᆠ㡰 m ⏌ ҈



㝐ᨨ

� � � 䰘� 㡰 ᆠ㡰 㡰 ҈l l l l ҈� 꾀 㜠矄  ᨨᆠ鼀 ᨨ  � ᨨ 矄ᨨ 盐 � ᨨ鼀鼀矄矄  矄�泐�矄矄盐矄  犨� 矄� �矄矄 ᨨ犨 �  ��盐ᔼ 꾀㦨ᔴ   �鼀 泐꾀犨�  ᨨ犨 犨 �ᆠ�矄q   ᲼㝐� 黨 ҈黨ᔼ桌 㡰

㡰

 q =

҈   

㡰  q =

 q =



    㡰 ᆠ㡰 㡰  � � � ҈䰘 꾀�ᆠᨨ 鼀矄矄m�矄鼀ᨨ� �ᨨ � 矄� ᨨ 矄⼄盐 ᨨ 矄� ἘaἘ犨� 盐 � ᨨ鼀矄 v�  x㜠y 矄矄 ᨨ犨

�   ��盐 ᲼㝐� ҈桌 泐 



 



     꾀    �



␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 矄 ᨨ  �盐 ur 鼀ᨨ鼀 盐鼀  ᨨ盐 ᨨ��� 䁸 ur é ù +  ú ├$ 犨   �ᆠ�矄鼀ᨨ� � ᨨ鼀 㡰  = 鼀 ê ë  û ᨨᔴ ur 鼀 ├$ 犨   �ᆠ�矄鼀ᨨ� � ᨨ鼀ᨨ꾀 㡰  㦨  ur 鼀 $ ├ 犨   �ᆠ�矄鼀ᨨ� � ᨨ鼀꾀ᨨ ᆠ㡰  㦨   ur é ù -  ú ├$ 犨   �ᆠ�矄鼀ᨨ� � ᨨ鼀 㡰  = 鼀 ê  ë û ᔴᨨ ҈ 꾀盐 � ᨨ鼀犨ᨨᨨ  矄�ᆠ├ᨨ 鼀矄矄҈├�  � l矄矄 �  � ᆠ�  鼀

ᨨ 矄鼀ᨨᨨ �ᆠ犨ᨨ  ��  l㡰矄盐ᆠ  矄鼀ᨨ�ᨨ ᨨ  矄�ᆠ├  矄泐ᨨ  犨  ᆠ�ᨨ  ᨨᆠᨨ  犨 ᨨ   矄�ᆠ├ �矄  �ᆠ盐ᨨ 矄�ᆠ├ 矄�ᆠ├鼀├矄  �ᨨ  犨�  犨  ᨨᨨ鼀ᨨ  矄�ᆠ├�矄ᨨ ᨨ盐� ᨨᨨ  ᆠ�ᨨ  ᨨ  犨 ᨨ   矄�ᆠ├ �矄 ⼄盐 �

鼀� �盐 ᨨ ᆠ�ᨨ ᨨ   ᨨᨨᨨ  矄�ᆠ├  �ᨨ ⏌l   �ᆠ�ᨨ  ᨨᆠf ᨨᨨ鼀ᨨ  矄�ᆠ├  �㦨҈鼀矄㡰 ᲼꾀 ҈桌

҈ 

҈   ҈ 꾀 � 盐 � ᨨ鼀ᨨ  �  鼀矄矄鼀�矄ᨨ 矄鼀ᨨᨨ ᨨ� ᨨ  犨ᨨᨨ� 鼀矄矄矄鼀 鼀鼀ᨨ� ��

 矄鼀 ᨨ� ᨨ   ᨨ鼀ᨨᨨ矄�矄� 矄ᨨ   ᆠ㡰



㡰



�㝐ᨨ

⏌

㡰

㡰  q =

 ҈   =  = l ҈ 

㡰

 ҈   =  = l ҈ 

      ҈   =  㡰  =  = = l ҈  l ҈  꾀�ᆠᨨ 鼀矄矄├��矄ᨨ 矄鼀ᨨᨨ  ᨨ� ᨨ   鼀ᨨ矄� ᆠ�ᆠ盐 ᨨ  �盐矄鼀  ��  ᨨ   ᨨ鼀 �ᨨ盐 �矄鼀ᔼ   �盐矄

ᆠ㡰

҈黨

WWW.JEEBOOKS.IN

P-53

System of Particles and Rotational Motion

20.

21.

22.

23.

24.

25.

of the particle is 12 rad s–1, the magnitude of its angular momentum about a point on the ground right under the centre of the circle is : [Main Online April 11, 2015] (a) 14.4 kg m2s–1 (b) 8.64 kg m2s–1 2 –1 (c) 20.16 kg m s (d) 11.52 kg m2s–1 A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed w rad/s about the vertical. About the point of suspension: [Main 2014] (a) angular momentum is conserved. (b) angular momentum changes in magnitude but not in direction. (c) angular momentum changes in direction but not in magnitude. (d) angular momentum changes both in direction and magnitude. A ball of mass 160 g is th rown up at an an gle of 60° to the horizontal at a speed of 10 ms–1. The angular momentum of the ball at the highest point of the trajectory with respect to the point from which the ball is thrown is nearly (g = 10 ms–2) [Main Online April 19, 2014] (a) 1.73 kg m2/s (b) 3.0 kg m2/s 2 (c) 3.46 kg m /s (d) 6.0 kg m2/s A particle of mass 2 kg is moving such that at time t, its r position, in meter, is given by r (t ) = 5iˆ - 2t 2 ˆj . The angular momentum of the particle at t = 2s about the origin in kg m–2 s–1 is : [Main Online April 23, 2013] (a) - 80 k$ (b) (10iˆ - 16 ˆj ) (c) -40k$ (d) 40k$ A bullet of mass 10 g and speed 500 m/s is fired into a door and gets embedded exactly at the centre of the door. The door is 1.0 m wide and weighs 12 kg. It is hinged at one end and rotates about a vertical axis practically without friction. The angular speed of the door just after the bullet embeds [Main Online April 9, 2013] into it will be : (a) 6.25 rad/sec (b) 0.625 rad/sec (c) 3.35 rad/sec (d) 0.335 rad/sec A small mass m is attached to a z massless string whose other end is fixed at P as shown in the figure. The P mass is undergoing circular motion in the x-y plane with centre at O and constant angular speed w. If the m O angular momentum of the system, calculated about O and P are denoted w r r by LO and LP respectively, then r r (a) LO and LP do not vary with time r r (b) LO varies with time while LP remains constant r r (c) LO remains constant while LP varies with time r r (d) LO and LP both vary with time A particle is confined to rotate in a circular path decreasing linear speed, then which of the following is correct? [2005S]

r L (angular momentum) is conserved about the centre r (b) only direction of angular momentum L is conserved (c) It spirals towards the centre (d) its acceleration is towards the centre. 26. A block of mass m is at rest under the action of force F against a wall as shown in figure. Which of the following statement is incorrect? [2005S] a (a) f = mg [f friction force] (a)

a

(b) F = N [N normal force]

F

(c) F will not produce torque (d) N will not produce torque 27. A horizontal circular plate is rotating about a vertical axis passing through its centre with an angular velocity wo. A man sitting at the centre having two blocks in his hands stretches out his hands so that the moment of inertia of the system doubles. If the kinetic energy of the system is K initially, its final kinetic energy will be [2004S] (a) 2 K (b) K/ 2 (c) K (d) K/ 4 28. A particle undergoes uniform circular motion. About which point on the plane of the circle, will the angular momentum of the particle remain conserved? [2003S] (a) centre of the circle (b) on the circumference of the circle. (c) inside the circle (d) outside the circle. 29. Consider a body, shown in figure, consisting of two identical balls, each of mass M connected by a light rigid rod. If an impulse J=MV is imparted to the body at one of its ends, what would be its angular velocity? [2003S] L

(a) V/L (b) 2V/L M (c) V/3L

M

J = MV (d) V/4L 30. A circular platform is free to rotate in a horizontal plane about a vertical axis passing through its centre. A tortoise is sitting at the edge of the platform. Now, the platform is given an angular velocity w0. When the tortoise move along a chord of the platform with a constant velocity (with respect to the platform), the angular velocity of the platform w(t) will vary with time t as [2002S] w(t )

w(t )

(a)

w0

(b)

w0

t

t

w( t )

w( t )

(c) w0

(d) w0 t

t

WWW.JEEBOOKS.IN

EBD_8341 P-54

҈







Physics

꾀 ⼄盐�� �ABC ᨨ鼀  ᨨ鼀盐 � ᨨ鼀犨� 矄犨ᨨ矄鼀�  �ᆠ 矄� ��泐ᨨᆠ A  � ��矄矄ᨨ� �ᨨ盐 �ᆠ �矄AO     矄矄  ᨨ鼀矄矄�鼀盐 ᨨ盐矄泐 ᨨ犨 ᨨ矄�  ᨨ犨 ᨨ ᨨ �AB  ᨨ ᨨ �AC矄 矄 ᨨ犨 �ᆠ� � �ᆠ�ᨨ  ᆠ矄 ⼄盐 ��矄  ᆠᨨ 矄 矄  矄矄�  ᨨ犨  ᲼和桌 㡰  �盐 ᨨᆠ�泐   ᨨ A  �泐 ├� �ᆠ ᨨ �㡰 㡰 ᨨ �盐鼀ᨨ鼀 盐鼀 g ᨨ �泐 ᆠ㡰  �盐ᨨᆠ�泐 鼀ᨨ鼀  ᨨ  � � ᨨ盐    �矄 ᨨ C B ᨨ�ᨨ

O 㡰 ᨨ �盐鼀ᨨ鼀 盐鼀 鼀ᨨ鼀  ᨨ  � � ᨨ盐    �矄ᨨ ᨨ�ᨨ

꾀 �矄ᆠᨨ 鼀矄矄M  �盐矄R�矄ᨨ� �犨�  �盐 矄 wᨨ  ᨨ� ᨨ  矄矄 ᨨ犨 �  ��盐  鼀� �盐 ᨨ  �盐鼀ᨨ鼀 盐鼀ᨨ   �矄ᆠᨨ盐  ᨨ��� O�矄 ᲼҈黨黨黨和㜠㝐├矄桌 Y 㡰 ҈⏌㡰MRw w 㡰 MRw M  ᆠ㡰 ⏌㡰MR w X 㡰 MRw O A鼀矄矄M鼀ᨨ� �犨� ᆠᨨ 矄 ᨨᆠ�泐ᨨ  X㜠 �矄ᔼ矄 �盐鼀ᨨ鼀 盐鼀犨� 矄ᆠᨨ ᨨ���

᲼҈黨�㜠㝐├矄桌 㡰 �矄 ᨨ 㡰 鼀� 矄ᆠᨨ 矄  ᆠ㡰 �ᨨ矄ᨨ � ᆠ矄� � 㡰 �ᨨ矄ᨨ  ᆠ矄� � 꾀 � ᆠ�ᆠ盐� �ᨨ 鼀矄矄�M  �盐矄r�矄ᨨ� � ᨨ盐�矄 �矄犨�   ᆠᨨ 矄  �盐 ᨨᆠ�泐w 犨ᨨ ᨨᆠ矄 ᆠ  ᨨ  鼀矄矄 m   ᆠ   � 泐 ᨨ   ᨨᨨ矄� 矄ᨨ  �鼀ᨨ  � � 犨  ᨨ犨 ᨨ矄犨�   �盐ᨨᆠ�泐 ᲼҈黨㜠҈㝐├桌 㡰

wM M + m㡰

㡰

w M   m㡰 M + m㡰

ᆠ㡰

wM M +  m㡰



w M + m㡰 M

2 �

Integer Value Answer

꾀 ᨨ� ᨨ ᆠ�ᆠ盐 ᨨ鼀ᨨ  �盐矄�鼀 鼀矄矄�├��矄 ᨨᨨᨨ盐�矄 �矄 犨ᨨ 鼀矄矄矄矄矄� �ᨨ泐㜠�盐 矄ᆠ ᆠ泐� �矄ᨨ 鼀矄矄�├�ᆠ  ᨨ   ᨨ鼀 �矄 ᆠ�鼀 ᨨ鼀 ᆠ ᨨ �矄�  矄� 矄 ᨨ � �矄 �鼀 矄 ��盐㡰 쟼ᆠ  �盐

矄�鼀盐 ᨨ盐矄泐 �矄   矄 ᨨ� ᨨ 泐   �ᆠ盐ᨨ  �鼀� ᨨᨨ矄� �ᆠ�ᨨ 矄꾀  � �  ᨨ鼀 矄  ᨨ� ᨨ 矄 ᨨ 黨 鼀矄҈犨� 矄ᆠᨨ �ᨨ盐  ᨨ�ᨨ 矄 ᨨ   ᨨ鼀�  矄҈  矄  ᨨ鼀�矄 ᲼꾀 ҈桌

 꾀盐 � ᨨ鼀ᆠ�ᆠ盐 �矄ᆠᨨ 鼀矄矄�├�  �盐矄鼀�矄 ᨨ� �犨�   �盐ᨨᆠ�泐ᨨ ҈ 矄҈ ᨨ盐�矄 ᨨ犨  �矄犨 �ᆠ �矄�ᆠ 犨ᨨ盐 � ᨨ鼀ᆠ�ᆠ盐� �矄 ᆠ ᨨ 鼀矄矄�├�  �盐矄鼀� 泐ᆠ 矄泐鼀鼀�ᆠ泐ᨨ   �矄ᆠ� 矄盐ᆠ 鼀

  泐 ᨨ盐ᆠ � � ᆠ ᨨ  ᨨ �    �矄 ᨨ    �矄ᆠ   ᨨ� ᨨ 꾀矄矄盐鼀   �ᆠ�ᨨ �矄� ᨨ盐� 矄盐ᆠ   � �矄矄�ᨨ  �矄ᆠ  矄泐矄鼀 ᨨ矄ᨨ盐 ᨨ���  �矄  犨 �盐ᨨᆠ�泐 ᲼꾀 ҈桌 �  矄҈㡰ᨨ  矄泐矄鼀�矄 䰘 꾀� 泐矄ᆠᨨ 矄�矄矄ᨨ 犨ᨨ矄矄꾀 鼀矄矄M矄㡰  鼀矄矄҈҈M矄㡰犨 Ms�矄 鼀矄矄ᨨ  矄盐  泐 矄 泐 �矄 ᆠ  ᨨ� �ᨨ盐 �ᆠ  ᨨ 鼀矄矄犨 �ᆠ �矄矄�ᨨ 泐 �ᨨᨨ  ᨨ �盐 鼀ᨨ鼀 盐鼀ᨨ  � 泐矄ᨨ  �盐鼀ᨨ鼀 盐鼀ᨨ 矄ᨨ盐 ᆠ ᨨ 鼀矄矄�矄 ᲼҈桌 3

Numeric Answer

 꾀 � ᨨ ᨨ 鼀矄矄黨├�  � ҈鼀�矄矄盐矄   矄 ᨨ鼀 ᨨ   矄ᨨ  � ᆠ  泐ᨨ矄ᆠ��    �ᆠ 꾀�ᆠᨨ 鼀ᨨ҈├�鼀ᨨ� �� 矄��  � 犨� ᨨᆠ�泐鼀⏌矄 �矄 ᨨ �矄ᨨᨨ鼀鼀ᨨ矄 ᨨ�  矄�ᆠ├矄ᨨ� 矄 ��盐㡰  �盐矄 �  ⏌矄㡰ᨨ  ᨨ �鼀鼀 �泐  ᆠᨨ�矄�ᨨ 犨� 힘힘힘힘힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和� ᔼᔼ㡰桌 黨 꾀矄ᨨ ᨨ ├�鼀矄矄�矄矄 � �ᨨ  �鼀ᨨ ᆠ�ᆠ盐  ᨨ鼀 ᨨ  鼀矄矄  ├� ᨨ� � ᨨ盐 �矄  �矄  � ᨨ盐�ᨨ 矄  鼀� 盐  鼀㡰   矄ᨨ  ᨨ犨 矄矄 鼀ᨨ� �ᨨ犨 矄 ᆠ ᨨ   ᨨ鼀␔ 犨�  ᨨ�ᨨ 矄  � 鼀㡰ᨨ   ᨨ鼀犨    矄ᨨ ᆠ 矄�矄ᆠ 힘힘힘힘힘힘힘힘힘힘 [Main Sep. 03, 2020 (I)]  盐盐 � ᨨ鼀鼀矄ᆠ ᨨ� ᨨ 泐ᨨ 泐ᨨ盐   �   � �矄犨�   ᨨ ᆠ鼀  �� ᨨ  黨ᆠ鼀␔  泐ᨨ盐鼀ᨨ鼀ᨨᨨ   � �矄 矄ᨨ犨泐ᨨ犨 矄 ᆠ � ��泐ᨨ 泐   � �矄�矄 犨� 矄ᆠᨨ 矄ᆠ  ��  � � ᨨ矄 ᨨ 꾀 矄ᨨ鼀 �矄 ᆠ   � �矄ᨨ矄  �� ᨨ  矄矄矄�� �   ��  � �矄ᨨ矄 �矄 ᆠxR ᨨ鼀 ᆠ  �ᆠ鼀㡰ᨨ  矄ᆠ   ᨨ  矄矄 矄�� � ��  �矄  矄 ᆠ盐矄 ᨨ    �  ᆠ�   �ᆠ�ᨨ  ᨨᆠ矄ᨨ  犨ᨨ � �矄ᔼ   ᆠᨨ �ᆠ� 矄ᨨ 矄�ᆠ  泐 鼀�ᆠ �ᆠ�ᨨ  犨    � �矄  矄ᆠ 矄ᆠ�泐  盐ᨨ xR � ᆠ鼀㡰�矄힘힘힘힘힘힘 ᲼꾀 桌 4

Fill in the Blanks

҈ 꾀矄ᨨ ᨨ 鼀矄矄m� ᨨ  ᨨ 矄� ��矄犨 � ᨨ盐 �  ᨨ� ᨨ ᆠ�ᆠ �ᆠ  ᨨᆠ 盐ᨨ ��泐㡰   �  ᨨ   矄� ��矄  盐ᆠ � 盐泐 ├� �   �盐 鼀ᨨ鼀 盐鼀 ᨨ  矄ᨨ ᨨ盐   ᆠ ᨨ  ᆠ�ᆠᆠᨨ 矄     矄�ᨨ �  矄� � �矄 ��  泐 T 㦨 Arn 犨  A �矄  ᆠᨨ 矄  r �矄   � 矄  ᨨ盐矄 �盐矄ᨨ  ᆠ�ᆠ n㦨 ᲼҈黨黨㜠҈㝐├桌

WWW.JEEBOOKS.IN

P-55

System of Particles and Rotational Motion





꾀ᆠ泐� ᨨ 鼀矄矄M  �盐矄R�矄矄� �ᨨ  ᨨ� ᨨ   ᨨ鼀 犨 �ᆠ �矄ᨨ xy 㡰犨� �矄 �矄 �  ᨨ � y㜠 �矄  ᨨᨨᨨ盐�矄 �矄   ᨨ鼀�矄�� 鼀ᨨ�ᨨ �  x㜠 �ᆠ�ᨨ �� 泐x㦨A ᆠᨨ矄 w t㡰 �矄 ᨨ矄�� �犨  ᆠ泐�   ᨨ鼀 鼀 �鼀盐鼀ᨨ⼄盐ᆠ� �ᨨ  ᆠ泐�  盐� � �矄鼀ᨨ�ᨨ �矄 ᲼҈黨㜠㝐├矄桌 꾀矄鼀ᨨᨨ 盐 � ᨨ鼀ᨨ ᨨ  � L 鼀矄矄M 矄犨ᨨ �  �ᆠ 矄ᨨ  ����矄� ᆠ ᨨ 鼀矄矄m犨 �ᆠ ᆠ 矄�  泐ᨨ � ᨨ ᔼ ��泐 犨ᨨ 矄  ᆠ ᨨ  ᨨ   矄泐矄鼀�矄ᨨ� �犨� 

 �盐ᨨᆠ�泐 w ᨨ盐  �矄 盐ᆠ盐ᨨ  ᨨ    矄矄� �  ᨨ盐�    鼀� ᨨ�  ᨨ    ᨨ  矄 ��盐㡰  ᨨ   ᨨᆠ矄␔    矄ᆠ   矄ᨨ  ᨨ   �盐ᨨᆠ�泐ᨨ  矄泐矄鼀�矄  ᲼҈黨㜠㝐├矄桌





 w

 ᔴᨨ 矄� ᨨ 泐ᨨ 鼀矄矄҈├�矄 ᨨ��� �鼀 r t㦨꾀 ᨨᆠ F = at �ˆ + bˆ 㡰 �矄� ᨨ  ᨨ 泐犨  a㦨҈矄҈ b㦨҈N ᨨ⼄盐ᆠ� �ᨨ  ᨨ 泐 r ᨨ盐  ᨨ���   �鼀t 㦨 ҈ s �矄 t ␔ �ᆠ  ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 㡰盐䁸 ᲼꾀 ҈桌 r ҈ 㡰  t = Nm  r 㡰 ᨨ⼄盐 t �矄�   �ᆠ�ᨨ ᨨ  盐 �ᆠᨨ졔 kˆ r ҈ ᆠ㡰 ᨨᆠ�泐ᨨ  ᨨ 泐t㦨҈s�矄 v = �ˆ +  ˆ 㡰ms ҈  ҈ 㡰 鼀� �盐 ᨨ  �矄ᆠ鼀 ᨨ  ᨨ 泐t㦨҈s�矄 m  䰘 ᨨ � �泐ᨨ �ᆠᨨ 鼀矄矄m �矄 ᆠ r ᨨ鼀 �  ᨨ� O�矄�� 泐V r㡰㦨kr⏌犨 k�矄 ᨨ矄��ᆠᨨ 矄 ᨨ ᨨ� �鼀 矄�ᨨ 矄 �矄�ᆠ �矄鼀ᨨ� �� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄Rᨨ盐 ᨨ� O ᔼ v�矄 矄 ᨨ  �ᆠ L�矄 鼀� �盐 ᨨ �矄 �盐鼀ᨨ鼀 盐鼀ᨨ盐O犨 �ᆠ ᨨ   ᨨᨨ犨� � 矄鼀 矄�矄 㡰盐䁸 ᲼꾀 ҈桌 k R m

㡰 v㦨



㡰 v㦨

mk  R   꾀犨 ᨨ  �盐矄  鼀矄矄㝐�矄ᆠ  ᨨᨨ鼀ᨨ  �  矄ᨨ  ��  矄矄 ᨨ犨 �   ��盐꾀ᆠᨨ 矄  ᨨᆠ�矄ᆠᨨ � 盐ᨨ盐矄泐� ᨨ  矄盐 ᆠᨨ  犨  矄ᨨ �盐矄ᆠ�鼀矄 矄犨� ᨨ盐矄�� �ᔴᨨ 矄�   ᨨ⼄盐tᨨ盐  �矄 ᨨ鼀ᨨ  ᨨ   矄矄� �  ᨨ盐�    ᨨ�  턼 ␔ �ᆠ  ᨨ    ᨨᨨ犨� � ᲼꾀 ҈䰘桌 ᨨ�ᨨ 矄�矄⏌ᆠᨨᆠ䁸

ᆠ㡰 L㦨 mk R 



5 True / False 꾀 � 盐 � ᨨ鼀ᆠ�ᆠ盐 �矄ᆠᨨ 鼀矄矄M  �盐矄R�矄 ᨨ� ��  ᨨ� ᨨ  ᨨ盐  �矄矄矄� � ᨨ盐� �矄ᆠ   �ᆠ盐ᨨ�矄 犨�   �盐 ᨨᆠ�泐 w 꾀 ᨨ  �矄ᆠᨨ  矄鼀 �鼀 矄�ᨨ 矄盐ᨨ 鼀矄矄M⏌�矄ᆠ � 泐ᨨ   �矄 �矄ᆠᆠᨨ �泐   �盐ᨨᆠ�泐ᨨ  矄泐矄鼀 ᨨ犨�矄 w ⏌ �  ᲼҈黨㜠㝐├矄桌 6

�

k R m

㡰 L㦨



MCQs with One or More than One Correct Answer

꾀ᨨ ᨨ 鼀矄矄m  � L�ᨨ ᨨ ᨨ �矄 矄�矄  �� ��ᆠ泐꾀盐ᨨ  矄鼀鼀矄矄鼀ᨨ� � 矄 v矄�├矄 ᨨ  ᨨ� ᨨ 泐 �矄 ᆠx ᨨ鼀�矄 �ᨨ      �矄 鼀   �  �  ᆠᨨ鼀�  矄泐矄鼀 ᨨ犨ᨨ矄犨�  �盐矄 wᨨ盐 �ᨨ

鼀 �鼀盐鼀 �盐矄 wM�矄ᆠ �  ᨨx = xM.



᲼꾀 桌

x

L

v

vx 㡰 w =  L + x  L ᆠ㡰 xM = 

҈vx 㡰 w =  L + ҈ x  v  㡰 wM = L



 

㡰 ᔼ   ᨨᆠ�矄� ᨨ�   � �泐 

ᆠ矄矄ᆠᨨ � 盐ᨨ盐矄泐矄 犨 ᆠ�鼀矄 㡰 ᔼ   ᨨᆠ�矄�  ᨨ鼀ᨨ ᆠ�ᆠ盐鼀  ᆠ ᨨ�   t�矄ᆠᨨ 矄  ᆠ㡰 ᔼ   ᨨᆠ�矄�  ᨨ鼀ᨨ ᆠ�ᆠ盐鼀  ᆠ ᨨ�   t�矄 ᨨ 㡰 ᔼ   ᨨᆠ�矄�  � �泐ᨨ� 和  t ¹ 盐 犨  ᆠ�鼀矄 矄 黨 꾀��� 盐 � ᨨ鼀꾀ᨨ  � �矄矄�� � ᨨ鼀�矄 �ᆠᨨ矄��ᨨ ᨨ  �ᆠ�ᨨ 矄矄 ᨨᨨ 矄矄 ᨨ犨 �   ��盐㡰 꾀矄ᨨ鼀� 矄 ᨨ �鼀  �鼀 泐 犨�   �ᆠ�矄q␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄ᨨ盐�矄 ᲼꾀 ҈䰘桌 鼀ᨨ�ᨨ �矄⏌ᆠᨨᆠ䁸

WWW.JEEBOOKS.IN

EBD_8341 P-56

Physics

꾀 q 





�

�҈

㡰 鼀� ᨨ� ᨨ  犨� �ᆠ泐 ᨨ犨 犨 㡰 ᆠᨨ泐ᨨ  ᨨ� 꾀�矄ᨨ ᆠ㡰 ᔼ 矄  ᨨ盐矄ᨨ⼄盐ᨨ盐 ᨨ� � ᆠᨨ ᆠ犨�   ᨨᨨ�矄ᨨᨨ�ᨨ ᨨ矄� q 㡰 ␔   鼀├矄  �q犨�  �ᆠ  �矄ᆠ鼀 ᨨ �矄鼀� ᨨ�  ᨨ鼀 � ��ᨨ矄��ᨨ

�矄ᨨᨨ�ᨨ ᨨ ҈ᆠᨨ矄q㡰

ᨨ矄��ᨨ ᆠᨨ r ᨨ �ᆠᨨ 鼀矄矄鼀�矄�� 泐   ᨨᨨ犨� �⼄盐�ᨨ

r  㡰㦨 a ˆ� + b ˆ  犨 a㦨҈⏌鼀矄b 㦨�鼀矄 鼀㦨҈├�꾀㦨҈矄 犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐ᨨ盐  �ᆠ䁸 ᲼꾀 ҈桌 r r ˆ ˆ 鼀矄҈ 㡰 ᨨᆠ�泐  �矄�� 泐  㦨 ҈� + ҈㡰 r 㡰  �盐鼀ᨨ鼀 盐鼀  犨� 矄ᆠᨨ ᨨ���

r �矄�� 泐  㦨�⏌㡰 ├ˆ 鼀矄 r r ᆠ㡰  ᨨᆠ �矄�� 泐 㦨 �ˆ + ˆ㡰  r 㡰 ᨨ⼄盐 t 犨� 矄ᆠᨨ ᨨ��� �矄�� 泐 r t 㦨 ⏌㡰 ├ˆ 鼀

犨ᨨ � ᆠ�ᆠ盐 �矄ᆠ矄ᨨ 鼀矄矄鼀 鼀 � � ��ᨨ  矄ᆠ�泐��� 泐 �  泐鼀矄矄矄矄

� 꾀� �ᨨ 鼀矄矄M  �盐矄R�矄ᨨ� �犨�  �盐 矄 wᨨ盐 �  �ᆠ �矄矄矄� � ᨨ盐�  �矄 M ᆠ O犨� 犨ᨨᨨ� 鼀矄矄矄ᆠ ᨨ 鼀矄矄 矄  O 矄鼀矄矄矄ᆠ 鼀ᨨ �泐ᨨ盐犨 矄ᨨ �犨ᨨ 鼀矄矄矄矄ᨨ 矄 �  ᨨ  � �矄矄 ᨨ犨 �   ��盐꾀  矄ᨨ鼀� 矄   �盐矄 ᨨ  矄泐矄鼀�矄 w 黨  ᨨ ᨨ  鼀矄矄矄�矄 �矄 ᆠᨨ   ᨨ鼀O꾀 �矄 � � 矄   �矄 ᆠᨨ  ᨨ 鼀矄矄 ᨨ鼀O�矄 ᲼꾀 ҈�桌 w



�



��� ᨨ ᨨ  � l㦨   ᨨ盐�  �ᆠ 矄 �矄 矄矄鼀泐�矄� ᨨ  �鼀  矄盐 ᆠ 矄ᨨ� � 犨� ᨨ盐矄�� �ᨨ  矄盐 ᆠ矄ᨨ   �盐矄 ᨨ盐  �矄ᨨ  ᨨ �矄w  �盐鼀ᨨ鼀 盐鼀ᨨ ur    �矄矄鼀泐ᨨ盐  ᨨ�  �졠�矄   矄   ��盐㡰␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌 鼀



l

m

w

l

 

졠 㡰  ᆠ  ᨨ  鼀矄矄 ᨨ    矄矄鼀泐ᨨ矄 ᨨ盐   㜠 �矄犨�   �盐矄 ᨨ w⏌� 㡰 鼀� �盐 ᨨ  �盐鼀ᨨ鼀 盐鼀ᨨ ᆠ  ᨨ 鼀矄矄ᨨ  矄矄鼀泐ᨨ盐 ᨨ� 졠�矄҈鼀w ᆠ㡰  鼀� �盐  ᨨ   �盐 鼀ᨨ鼀 盐鼀 ᨨ    矄矄鼀泐ᨨ盐�矄ᆠ ᨨ 鼀矄矄�矄҈䰘鼀w⏌ ur 㡰 鼀� �盐 ᨨ   㜠ᆠᨨ鼀ᨨ  ᨨ   �矄��鼀w

 ҈   㡰 ᆠ㡰 㡰   � � ᔼ   ��盐 ᨨ 鼀矄矄m�矄矄 ᨨ犨  � ��� 矄 犨ᔼ�矄� 矄�ᆠ⼄盐���盐鼀鼀├� �  �q犨�   ᨨ� ᨨ  ᨨᨨ ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ 犨    犨   �矄m҈  犨   ᨨᨨ   �矄m  ᨨ鼀ᆠ�ᨨ ᨨ  犨ᨨ    �矄N҈  ᨨ   ᨨᨨ�矄Nᔼ   �矄 ᨨ盐ᨨ矄�   ᲼꾀  ҈桌

㡰

m҈ =  m  ¹   N q㦨

㡰

m҈ ¹  m

ᆠ㡰

m҈ ¹  m

mg  ᔼ  矄盐 ᨨ     ᨨᆠ矄ᆠ� �ᨨ 矄泐矄鼀 ᨨ �ᆠ矄�矄 ᨨ   ᨨ鼀 � � 鼀ᨨ ᆠ

矄盐泐矄泐  ᲼黨桌 㡰 � 鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 ᨨ矄 ᨨᆠ  ��

�鼀 㡰 ├� �ᆠ  �泐ᨨ    矄泐矄鼀  ᨨ矄 ᨨ ᆠ  � �

�鼀 ᆠ㡰  �盐鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 ᨨ矄 ᨨᆠ  ��

�鼀 㡰 ᨨ � �泐ᨨ  矄泐矄鼀 ᨨ矄 ᨨᆠ  ��

�鼀

㡰 �

mg  mg =    N҈  q =  mg ¹    N  = ҈ + m m ҈ 

㡰

m҈ =  m  ¹    N҈  q =

WWW.JEEBOOKS.IN

P-57

System of Particles and Rotational Motion

��

ᨨ⼄盐 t ᨨ ᨨ 泐ᨨ盐�� ᨨ� �矄 ᨨ盐 ᨨ ⼄盐ᨨA맔L犨 A�矄ᆠᨨ 矄 ᆠᨨ L�矄   �盐鼀ᨨ鼀 盐鼀ᨨ  ᨨ 泐ᨨ盐 ᨨ�  ᨨ鼀  �矄� ᨨᨨ犨矄  ᲼҈黨黨和㜠㝐├矄桌 dL �矄 �ᆠ盐ᨨL� 矄 矄ᨨ �鼀 dt 㡰  ᆠᨨ鼀ᨨ   ᨨ L�   �ᆠ�ᨨ ᨨ A ᨨ矄 ᨨ ᆠ  �犨� �鼀 ᆠ㡰  鼀� �盐 ᨨ L ᨨ矄 ᨨᆠ  �犨� �鼀 㡰 L ᨨ矄 ᨨᆠ  �犨� �鼀 꾀�ᆠᨨ 鼀矄矄m�矄ᨨᆠ 犨� ᨨᆠ�泐v鼀├� �   �ᨨ � 犨�   ᨨ� ᨨ  鼀� �盐 ᨨ  

 �盐鼀ᨨ鼀 盐鼀ᨨ  ᨨᆠ�ᨨ盐 ᨨ� ᨨ ᨨᆠ�ᨨ 犨   �ᆠ�矄�矄鼀 �鼀盐鼀 �� h�矄 ᲼҈黨黨㜠㝐├矄桌  mv 㡰 ᨨ 㡰  g

㡰

�

ᆠ㡰

mv





g

m  gh

10 Subjective Problems �䰘 꾀�ᆠ�矄ᨨᆠ �鼀t㦨 ᨨ鼀ᨨ� Pᨨ   �ᨨ盐 犨� 矄 v  �ᨨ � ᨨ  ᨨ� ᨨ  �  鼀� �盐   �ᆠ�ᨨ ᨨ   �盐鼀ᨨ鼀 盐鼀 ᨨ  �ᆠᨨ盐P�鼀t㦨v⏌g ᲼҈黨㜠㝐├矄桌

Topic-4 : Moment of Inertia and Rotational K.E. 1 ҈

ᨨ盐 � 矄�矄I҈I㦨҈҈   盐ᨨ a�矄 ᲼㝐� 和 ᔼᔼ㡰桌

MCQs with One Correct Answer

和 ᨨ犨 �   ��盐�矄 ᨨᨨ犨�ᆠᆠ鼀ᆠᨨ  ��矄ᨨ   ᨨ㡰ᔼ �矄鼀矄矄�矄M �盐矄ᨨ �矄ᨨR  �� H   �矄鼀ᨨ鼀 ᨨ � �ᨨ盐�矄 �矄�矄 ᲼㝐� 和 ᔼ㡰桌

�

㡰 y

 

㡰



ᆠ㡰 

㡰 

O' O

ᆠ鼀





MR  M R + H  㡰 㡰 㡰     MH MR ᆠ㡰 㡰  

� 鼀矄矄  矄�泐ᨨ  � ᨨ 꾀ᨨ  � �矄 xö æ ᨨ鼀꾀ᨨ矄 l x 㡰 = l  ç҈ + ÷ 犨 x�矄  �矄 ᆠ è ø ᨨ鼀꾀ᔼ 㝐�矄 鼀矄矄ᨨ  ᨨ   �矄鼀ᨨ鼀 ᨨ � � ᨨ盐  �矄矄矄� � ᨨ盐� 꾀  �ᆠ盐ᨨ  ᨨ �矄 ᲼㝐� 和 ᔼᔼ㡰桌

5 䰘   㝐 㡰 㝐 ᆠ㡰 㝐 㡰 㝐 ҈ ҈ � 䰘 꾀犨 �矄ᨨ� � 泐犨�   �盐矄 wᨨ  矄   鼀ᨨ鼀 ᨨ � �ᨨ  犨 �矄ᔼ  鼀ᨨ㜠 鼀 ᨨ � �ᨨ  矄  �矄 ����꾀 ᨨ 犨 ᨨ 鼀ᨨ鼀 ᨨ � �ᔼ� ��泐矄�矄矄盐  泐ᆠᨨ盐 ᨨ   矄鼀 矄    矄盐  ᆠ�ᨨ  ᨨ矄矄 �    ├� �ᆠ �泐ᨨ  矄泐矄鼀�矄 ᲼㝐� 和� ᔼ㡰桌



æ R  L ö I = M çç + ÷÷  ᔼ 矄盐ᆠ ᆠ泐� �矄ᨨ鼀  ᨨ è  ҈ ø �� 鼀矄矄ᨨ 鼀� �ᨨL/R ᨨ�ᨨ 鼀� �鼀盐鼀 ᨨ矄矄�I�矄 [Main Sep. 03, 2020 (I)]

㡰



� ҈  㡰 ᆠ㡰  㡰    ᔴᨨ 矄�  犨ᨨ盐 � ᨨ鼀 �矄ᆠ矄ᨨ  矄鼀 �ᆠ├ 矄矄  �   ��R҈㦨R R㦨aR鼀 ᨨ  矄鼀鼀� ᔼ  �ᨨᨨ  �鼀ᨨ鼀 矄ᨨ � �I҈ I矄ᆠ�泐

㡰



x ᆠ鼀 ᨨ盐 � ᨨ鼀ᆠ �盐矄 矄 ᨨ犨 �   ��盐  �ᨨᨨ 鼀ᨨ鼀 矄ᨨ � �ᨨ盐  矄 �ᆠ盐ᨨ  矄  矄矄� � ᨨ盐� O  ᆠ ᨨ 鼀矄矄㡰 OἘ ᆠᨨ ᨨ� 㡰�矄 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 ⏌ 㡰 ҈⏌ ᆠ㡰 ҈⏌ 㡰 ҈⏌ 㝐ᨨ鼀 ᨨ � �ᨨ ᆠ泐� ᨨ 鼀矄矄M � L  �盐矄 R ᨨ盐   �矄 矄矄� �  ᨨ盐� �矄 ᆠ    �ᆠ盐 ᨨ    �矄 ᨨ    ᆠ泐�  �矄

    㡰 ᆠ㡰 㡰    

犨ᨨ盐 � ᨨ鼀ᆠ�ᆠ盐 �矄ᆠ矄ᨨ� ��   泐�

  矄鼀 �ᆠ�ᨨ  ᨨ盐   � ᆠᨨ鼀鼀ᨨ   �矄 矄矄� �  ᨨ盐�  �ᆠ 矄 鼀ᨨ鼀 ᨨ � �  �盐 ᨨᆠ�泐ᨨ   �矄 �矄ᆠ  ҈ ├�㜠鼀   ҈   矄҈ 矄ᆠ�泐犨 � ᨨ矄 ᨨ 矄ᆠᨨ ᨨ ├�㜠鼀   � 矄҈矄ᆠ�泐꾀矄ᨨ鼀� 矄  泐�矄盐ᆠ├ ᨨ�  矄ᨨ� �矄矄� �矄泐矄鼀ᨨ盐 � ᆠᨨ鼀鼀ᨨ  �矄犨� 矄ᨨ鼀 �盐矄  ├� �ᆠ �泐 ᨨ  ᆠᨨ鼀�  矄泐矄鼀�矄 [Main Sep.02, 2020 (II)]

㡰 䰘

㡰

҈  

㡰

  

ᆠ㡰

�  



  

WWW.JEEBOOKS.IN

EBD_8341 P-58



黨

Physics

矄ᨨ� 矄 矄ᆠ  ᨨ 鼀矄矄m  �鼀d 矄盐ᆠ├ᨨ� 矄盐ᆠ   � 矄ᆠᨨ

ᆠ� � ᆠ 矄 ᨨ鼀 ⼄盐�� �ᨨ 矄� ᨨ  � d �ᨨ ᔼ ᨨ 鼀ᨨ鼀 ᨨ � �ᔼᨨ  矄泐矄鼀ᨨ盐  �矄 ᔼ꾀 矄矄� � ᆠ ᨨ�  ᨨ盐ᆠ ᨨ  泐ᨨ  矄 矄 ᔼ꾀  �ᆠ盐ᨨ  ᨨ  � ��矄 ᲼㝐� 黨 ᔼ桌 ҈ 㡰  ҈� 㡰 ҈  ᆠ㡰 ҈ ҈ 㡰 ҈� 꾀盐 � ᨨ鼀泐 �ᆠ├犨 犨� 鼀ᨨ鼀 ᨨ � �ᔼ  �盐矄 �矄 ᨨ ᨨᨨ盐 �矄 ᆠ  ᨨ  鼀矄矄 矄 ��㡰꾀 鼀矄矄矄矄矄� ��矄犨 ᨨ�矄�鼀 犨ᨨᨨᆠ├矄ᨨ 鼀矄矄矄m҈ m m҈>m㡰ᆠ  ᨨ  矄ᨨ   矄� � 矄泐矄鼀�矄矄  ᨨ鼀矄  �盐矄 ᨨ  犨 犨  m҈ 矄ᆠ 矄泐 �矄 ᆠh�矄 ᲼㝐� 黨 ᔼᔼ桌

҈҈  �盐矄ᨨ �泐�ᨨ ᨨ 盐 � ᨨ鼀ᨨ ᨨ  � lᨨ盐 l   �矄矄矄� � ᨨ盐� ᨨ�  犨泐 ᨨ鼀 ᆠ ᨨ   ᨨ   �ᆠ盐ᨨ��矄᲼㝐� 䰘 ᔼ桌 ҈ ҈ 䰘  l l l l 㡰 ᆠ㡰 㡰     ҈ 㝐矄矄盐 �ᨨ ᆠ�ᆠ盐 �矄ᆠᨨ  �盐矄  矄ᨨ

  �矄 ᆠr ᨨ鼀�矄ᆠ 矄s r㡰㦨A 졔Br 鼀ᨨ鼀  ᨨ � �ᨨ   �矄ᆠᨨ盐  �矄 �ᆠ盐ᨨ    矄矄� � ᨨ盐� �矄ᆠ �矄 ᲼㝐� 䰘 ᔼᔼ桌

㡰

aB ö æ A 㡰 pa çè + ÷ø  �

Bö  æ aA + ÷ 㡰 pa çè  �ø

Bö  æ A aB ö æA ᆠ㡰 pa çè + ÷ø 㡰 pa çè + ÷ø  �  � ҈ 꾀ᆠ�ᆠ盐 �矄ᆠᨨ  �盐矄b 矄 ᨨᨨ  �盐矄a�矄ᆠ  矄 ��盐㡰ᔼ  鼀矄矄盐 �ᨨ   �矄ᆠ�矄矄 æ s ö ç ÷     �盐矄ᨨ �泐�ᨨ ᨨ   �矄ᆠᨨ盐�矄 �矄 è r ø 矄矄� � ᨨ盐�  ᆠ �矄 ᲼㝐� ҈꾀҈黨ᔼ桌

҈⏌ 

㡰

a + b + ab 

㡰

a+b  

҈⏌ 

ᆠ㡰

a + b + ab 



a+b 

é  m҈ - m 㡰 gh ù ú 㡰 ê  ëê m҈ + m 㡰 + ҈ ûú é  m҈ + m 㡰 gh ù ú 㡰 ê  êë m҈ + m 㡰 + ҈ úû

҈ 犨ᨨᆠᨨ � �矄ᆠ矄 � �鼀ᨨ鼀 矄ᨨ � �ᔼ҈ 

҈⏌

é m҈ - m 㡰 ù ú ᆠ㡰 ê  ëê m҈ + m 㡰 + ҈ ûú

gh

҈⏌

é ù m҈ + m ú gh 㡰 ê  êë m҈ + m 㡰 + ҈ úû ҈ 꾀矄 矄 ᨨ犨  �    ��盐  ᨨ ᨨ  鼀矄矄 m �矄 � 泐  鼀矄矄矄矄矄� �犨 ᨨ矄ᨨ  ᨨ�ᨨ �矄犨ᨨ盐 ᨨ  泐 犨  �矄ᆠ㡰ᨨ  �盐矄 鼀矄矄鼀␔  矄  ᨨ鼀 矄 ᨨ矄矄 � ��ᆠ泐␔  � 矄ᆠᨨ  �矄 ᆠᨨ    �盐矄 ᨨ  犨 犨� ᲼㝐� 䰘 ᔼ桌

ᔼ҈  

w҈ ᨨ盐   �ᆠᨨ鼀鼀ᨨ  �矄 泐ᨨ盐� � ᆠᨨ ᆠ犨� ᆠ ᨨ     泐ᨨ犨� ᆠᨨ鼀鼀ᨨ  �盐 ᨨᆠ�泐ᔼ 쟼  쟼�  �  � ��ᨨ ��矄    쟼 쟼�㡰�矄 ᲼㝐� ҈꾀҈黨ᔼ桌

ᨨ� �犨� 矄ᆠ� �盐ᨨᆠ��矄w҈ 

  ᔼ w ᔼ҈w҈ ᔼ w ᔼ҈w҈ 㡰 ҈ ҈ ᆠ㡰 㡰 - ҈ ҈   ҈  ҈� 꾀 �  �矄ᆠᨨ 鼀矄矄㝐  �盐矄  矄鼀矄矄盐 � s r㡰㦨kr犨 r�矄  �矄 ᆠ ᨨ鼀�矄ᆠ ᔼ矄鼀ᨨ鼀  ᨨ � �ᨨ盐  �矄�ᨨ� � ᨨ盐� �矄ᆠ ᨨ 鼀矄矄   �ᆠ盐ᨨ�矄 �矄 ᲼㝐� ҈꾀҈黨ᔼ桌

㡰 -

㝐  㝐  㡰    㝐 㝐  ᆠ㡰 㡰   ҈ 꾀矄ᨨ� 矄 ᨨ 鼀矄矄㝐  �盐矄 �矄 ��  � ᨨ犨ᨨ

㡰

㡰

҈  gh  r

҈  gh ᆠ㡰  r

㡰 r

  gh

 r 㡰  gh

䰘M  �矄  ᆠᨨ  � ᨨ盐 � ᨨ鼀 �矄ᆠᨨ  �盐矄  矄ᆠᨨ

盐 ⼄盐矄  �矄 矄鼀矄矄ᨨ 

WWW.JEEBOOKS.IN

P-59

System of Particles and Rotational Motion

part is converted into a uniform solid sphere. Let I1 be the moment of inertia of the new sphere about its axis. The ratio I1/I2 is given by : [Main 10 Apr. 2019 II] (a) 185 (b) 140 (c) 285 (d) 65 17. A stationary horizontal disc is free to rotate about its axis. When a torque is applied on it, its kinetic energy as a function of q, where q is the angle by which it has rotated, is given as kqn. If its moment of inertia is I then the angular acceleration of the disc is: [Main 9 April 2019 I] k k k 2k q q (c) 2 I q q (a) (b) (d) 4I I I 18. A thin smooth rod of length L and mass M is rotating freely with angular speed w0 about an axis perpendicular to the rod and passing through its center. Two beads of mass m and negligible size are at the center of the rod initially. The beads are free to slide along the rod. The angular speed of the system, when the beads reach the opposite ends of the rod, will be: [Main 9 Apr. 2019 II] M w0 M w0 (a) (b) M +m M + 3m M w0 M w0 (c) (d) M + 6m M + 2m 19. A thin circular plate of mass M and radius R has its density varying as r(r) = r0 r with r0 as constant and r is the distance from its center. The moment of Inertia of the circular plate about an axis perpendicular to the plate and passing through its edge is I = a MR2. The value of the coefficient a is: [Main 8 April 2019 I] 3 (a) 1 2 (b) 3 5 (c) 8 5 (d) 2 20. Let the moment of inertia of a hollow cylinder of length 30 cm (inner radius 10 cm and outer radius 20 cm), about its axis be 1. The radius of a thin cylinder of the same mass such that its moment of inertia about its axis is also I, is: [Main 12 Jan. 2019 I] (a) 12 cm (b) 16 cm (c) 14 cm (d) 18 cm 21. The moment of inertia of a solid sphere, about an axis parallel to its diameter and at a distance of x from it, is ‘I(x)’. Which one of the graphs represents the variation of I(x) with x correctly? [Main 12 Jan. 2019 II]

I(x)

I(x)

(a)

(b)

O

x

O

I(x)

I(x)

(c)

22.

x

triangle DEF is removed from ABC, the moment of inertia of the remaining figure about the same axis is I. Then : [Main 11 Jan. 2019 I] A

E

D

G B

23.

C

F

15 3 (b) I = I0 (a) I = I0 16 4 9 I (c) I = I0 (d) I = 0 16 4 a string is wound around a hollow cylinder of mass 5 kg and radius 0.5 m. If the string is now pulled with a horizontal force of 40 N, and the cylinder is rolling without slipping on a horizontal surface (see figure), then the angular acceleration of the cylinder will be (Neglect the mass and thickness of the string) [Main 11 Jan. 2019 II] 40 N

(a) 20 rad/s2 (b) 16 rad/s2 2 (c) 12 rad/s (d) 10 rad/s2 24. A circular disc D1 of mass M and radius R has two identical discs D2 and D3 of the same mass M and radius R attached rigidly at its opposite ends (see figure). The moment of inertia of the system about the axis OO’, passing through the centre of D1, as shown in the figure, will be : [Main 11 Jan. 2019 II] O'

D2

O

D3

D1

(a) MR2

(b) 3MR2

(c)

4 MR 2 (d) 5

2 MR 2 3

m are connected at the two ends of a 2 massless rigid rod of length l. The rod is suspended by a thin wire of torsional constant k at the centre of mass of the rod-mass system (see figure). Because of torsional constant k, the restoring toruque is t= kq for angular displacement q. If the rod is rotated by q0 and released, the tension in it when it passes through its mean position will be: [Main 9 Jan. 2019 I]

25. Two masses m and

(d)

x x O O An equilateral triangle ABC is cut from a thin solid sheet of wood. (See figure) D, E and F are the mid-points of its sides as shown and G is the centre of the triangle. The moment of inertia of the triangle about an axis passing through G and perpendicular to the plane of the triangle is I0. If the smaller

(a)

3k q0 2 l

(b)

2k q0 2 l

(c)

k q0 2 l

(d)

k q0 2 2l

WWW.JEEBOOKS.IN

EBD_8341 P-60



Physics

꾀ᨨ ᨨ  � �ᆠ鼀�矄�ᨨ ᨨ  ᔼ�矄�矄 矄盐ᆠ  � 鼀├矄  �ᨨ   ᨨ鼀  ᨨ� ᨨ 矄 矄 ᨨ犨    矄  ᨨ鼀 矄 ᔼ矄  �盐 矄  犨 

� 矄矄矄  ᨨ盐�    ᨨ� ᨨ  �   矄҈㡰 犨�  �㦨҈鼀矄㡰 ᲼㝐� 黨 ҈黨ᔼᔼ桌



�矄鼀 �  � 盐 � ᨨ鼀 �矄ᆠ  � �鼀矄矄㝐  �盐矄 矄矄 ᨨ犨 �  ��盐  鼀ᨨ鼀 ᨨ � �ᨨ  鼀� � �ᨨ�ᨨ ᨨ   �矄ᆠᨨ盐   �矄矄矄� � ᨨ盐�  ᨨ� 졠  �ᆠ盐ᨨ   ᨨ   �矄ᆠ�矄 ᲼㝐� 졠 � 꾀�黨҈䰘桌 ҈黨 㝐  㡰  �

҈ 꾀ᆠ�ᆠ盐 ᨨᨨ  �盐矄

䰘 㝐  ⏌ �҈ ᨨἘ 졠 ҈黨 㝐  ᆠ㡰  ⏌ �҈ ҈黨䰘 㝐  㡰 �  ᨨ鼀  矄ᨨ� 矄  ᨨ 鼀矄矄 㝐   �盐矄   ᆠ盐 ᨨ 鼀 �鼀盐鼀ᨨ矄矄�ᨨ盐鼀�矄ᆠ盐㝐ᨨ鼀 ᨨ � �ᨨ ᆠ盐 ᨨ盐  �矄矄矄� � ᨨ盐� �矄ᆠ   �ᆠ盐 ᨨᨨ ᨨ �矄 ᆠ矄�矄 ᲼㝐� ҈�桌 㝐  㝐  㡰 㡰 黨 p  p  㝐 㝐  ᆠ㡰 㡰  p ҈ p  ᔴᨨ 矄�    �  盐 � ᨨ鼀 矄⼄盐 矄  鼀  ᨨ   ��� 鼀�ᔼ �矄矄� �矄�a鼀矄矄m 鼀ᨨ鼀 ᨨ � �ᔼ ᨨ盐ᨨ ᨨ �矄 ��ᨨ 矄   ᲼㝐� 졠 � 꾀�҈҈�桌

㡰

   㡰 ᆠ㡰 㡰    䰘 䰘 和 �  �ᆠᆠ�ᆠ盐  �矄├矄ᆠ ᨨ 鼀矄矄㝐  �盐矄 犨  矄泐鼀鼀�ᆠ泐矄矄 ᨨ犨  鼀ᨨ鼀  ᨨ � �ᨨ   �鼀 ᨨ盐  �矄 ᨨ鼀ᨨ    矄矄� � ᨨ盐�  ᨨ� �矄 ᲼㝐� ҈桌 㡰

 졠

҈黨 �� 䰘 ҈҈ 㝐  㡰 㝐  ᆠ㡰 㝐   㡰 㝐      ᨨ鼀盐 � ᨨ鼀ᆠ�ᆠ盐 �矄ᆠᨨ  �盐矄  鼀矄矄黨㝐

㡰 

�矄鼀ᨨ 矄矄 ᨨ犨 �   ��盐 

鼀ᨨ鼀 ᨨ � �ᨨ  鼀� � � �矄ᆠᨨ盐  �矄  �ᆠ盐ᨨ  ᨨ   �矄ᆠ 矄矄� � ᨨ盐� ᆠ ᨨ  �矄ᆠ�矄 ᲼㝐� ҈桌 矄鼀 �矄ᆠᨨ  �盐矄

㡰



 䰘 㝐  ᆠ㡰҈㝐  㡰 㝐  黨 黨 꾀 �  ᆠ�ᆠ盐 �矄├�矄�   泐 矄矄 ᨨ犨 �   ��盐 �ᨨᨨ �矄鼀ᨨ鼀 ᨨ � �ᨨ盐   ¢ 矄 犨� ᲼㝐� 졠 � 꾀�҈҈桌

㡰 㝐 

黨

㡰

z



x





y

㡰 ҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈�

鼀ᨨ鼀 ᨨ � �ᨨ 盐 � ᨨ鼀ᆠ泐� ᨨ  � l  �盐矄 ᨨ盐�矄 �ᆠ盐�矄ᆠᨨ�矄ᔼ␔ �矄  �ᨨl⏌ 矄盐ᆠ   鼀ᨨ鼀 ᨨ � ��矄鼀� �鼀盐鼀䁸 ᲼㝐� ҈䰘桌    㡰 ҈ 㡰 ᆠ㡰 㡰   

鼀  ҈

㡰

鼀  鼀 

ᔼ=

Mm m M + m㡰   w R w R 㡰 M + m㡰 M Mm M + m㡰 M   w R w R ᆠ㡰 㡰 M +  m㡰 M + m㡰 � 꾀矄ᨨ� 矄 ᨨ 鼀矄矄M  �盐矄R � �鼀ᨨ鼀 ᨨ � �ᔼᨨ盐�矄 �鼀�矄ᆠ矄� ᨨ矄ᨨ�  �矄ᆠᨨ  �盐矄r  �ᆠ├ 矄矄t 鼀ᨨ鼀 ᨨ � �ᨨ   �矄ᆠ ᨨ盐  �矄矄矄� �  �  �ᆠ盐ᨨ   鼀� 矄I  R r 矄 ᲼㜠㝐҈桌 㡰

㡰

r=

ᆠ㡰

r=

 R ҈�  R ҈�

㡰

r=





r=

 R ҈�

҈�

R

WWW.JEEBOOKS.IN

P-61

System of Particles and Rotational Motion

36. From a circular disc of radius R and mass 9M, a small disc of radius R/3 is removed from the disc. The m oment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through O is [2005S] (a) 4MR2 R 3

40 MR 2 (b) 9

R

(c) 10 MR 2 (d) 37.

2R/3

37 MR 2 9

IO and IP respectively. Both these axes are perpendicular to the plane of the lamina. The ratio IP / IO to the nearest integer is [2012] 42. Four solid spheres each of diameter 5 cm and mass 0.5 kg are placed with their centers at the corners of a square of side 4 cm. The moment of inertia of the system about the diagonal of the square is N ´ 10–4 kg– m2, then N is. [2011] 3

One quarter sector is cut from a uniform circular disc of radius R. This sector has mass M. It is made to rotate about a line perpendicular to its plane and passing through the center of the original disc. Its moment of inertia about the axis of rotation is [2001S]

Numeric Answer

43. ABC is a plane lamina of the shape of an equilateral triangle. D, E are mid points of AB, AC and G is the centroid of the lamina. Moment of inertia of the lamina about an axis passing through G and perpendicular to the plane ABC is I0. If part ADE is removed, the moment of inertia of the NI 0 where N is an 16 integer. Value of N is _______. [Main Sep. 04, 2020 (I)]

remaining part about the same axis is (a)

38.

1 MR 2 (b) 2

A

1 MR 2 (d) (c) 2 MR 2 8 A thin wire of length L and uniform linear mass density r is bent into a circular loop with centre at O as shown. The moment of inertia of the loop about the axis XX' is [2000S]

(a)

rL3 8p

(b)

2 3

(c)

39.

1 MR 2 4

5rL

16p

X

2

X' 90º

3

(d)

3rL

8p2 16p Let I be the moment of inertia of a uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle q with AB. The moment of inertia of the plate about the axis CD is then equal to [1998S - 2 Marks] (a) I (b) I sin2 q 2 (c) I cos q (d) I cos2 (q/2) 2

2

rL3

Integer Value Answer

40. The densities of two solid spheres A and B of the same r radii R vary with radial distance r as rA(r) = k æç ö÷ and R è ø 5 ærö rB(r) = k ç ÷ , respectively, where k is a constant. The è Rø moments of inertia of the individual spheres about axes passing through their centres are IA and IB, respectively. If IB n = , the value of n is [Adv. 2015] I A 10 41.

A lamina is made by removing a small disc of diameter 2R from a bigger disc of uniform mass density and radius 2R, as shown in the figure. The moment of inertia of this lamina about axes passing though O and P is

E

D

G B

C

44. A circular disc of mass M and radius R is rotating about its axis with angular speed w1. If another stationary disc R having radius and same mass M is dropped co-axially 2 on to the rotating disc. Gradually both discs attain constant angular speed w2. The energy lost in the process is p奠 of the initial energy. Value of p is ___________. [Main Sep. 04, 2020 (I)] 45. An massless equilateral triangle EFG of side 'a' (As shown in figure) has three particles of mass m situated at its vertices. The moment of inertia of the system about the N ma 2 line EX perpendicular to EG in the plane of EFG is 20 where N is an integer. The value of N is _________. [Main Sep. 03, 2020 (II)] X

E

F

a

G

46. One end of a straight uniform 1 m long bar is pivoted on horizontal table. It is released from rest when it makes an angle 30° from the horizontal (see figure). Its angular speed when it hits the table is given as ns -1 , where n is an integer. The value of n is ________ . [Main 9 Jan. 2020 I]

WWW.JEEBOOKS.IN

EBD_8341 P-62

䰘

Physics

4 Fill in the Blanks 꾀 矄泐鼀鼀�ᆠ 鼀�  ᨨ 鼀矄矄 M ᆠᨨ 矄�矄矄 ᨨ  A B 矄⼄盐 矄  犨�   矄鼀�ᆠ�ᆠ盐矄ᆠ�ᨨ ᨨ ᨨ   �ᨨ  矄⼄盐 矄 矄 ᨨ犨  �  �� 㜠҈ a

矄� ᨨ  矄⼄盐�矄 a 鼀ᨨ鼀 ᨨ � � O ᨨ    鼀�  ᨨ盐 

 �矄 ᨨ盐� �矄ᆠ ᨨ 鼀矄矄   �ᆠ盐 ᨨ  �矄҈Ma

鼀ᨨ鼀 ᨨ � �ᨨ  鼀� ᨨ盐  � AB �   ᨨ  鼀� �矄 ᲼҈黨黨䰘㜠㝐├矄桌

6

MCQs with One or More than One Correct Answer

 鼀ᨨ鼀 ᨨ � �ᨨ  � 矄⼄盐ABCD ��ᨨ 盐 � ᨨ鼀 �ᆠ├ 矄矄ᨨ盐  �矄矄矄� � ᨨ盐�  ᆠ  O  �ᆠ盐ᨨ  ᨨ  �矄 ᲼҈黨黨㜠㝐├矄桌  ҈ 㡰 I҈ + I   꾀  㡰 I + I  졠 

ᆠ㡰

I҈ + I



I҈ + I  + I + I 







犨  I҈  I   I  I  矄ᆠ�泐 鼀ᨨ鼀 矄ᨨ � �ᨨ盐 �矄҈ 犨 �ᆠ �   ᨨ   

Topic-5 : Rolling Motion 1 ҈





MCQs with One Correct Answer

꾀盐 � ᨨ鼀矄 ᨨ 鼀矄矄��ᨨ矄犨� ᨨ盐矄�� �ᨨ    ᨨ� ᨨ 矄盐 ᆠ犨� �矄ᆠ 鼀ᨨ� �矄 ᨨ �ᆠ鼀⏌矄ᔼ矄├� �ᆠ �泐�矄᲼㝐�  ᔼᔼ桌 㡰 䰘�맔҈ 㡰 䰘�맔҈ ᆠ㡰 �맔҈ 㡰 1.13 × 10 꾀矄鼀ᨨᨨ  �鼀ᆠ鼀 矄  ᨨ  �鼀҈ ᆠ鼀 矄 ��盐ᨨ犨ᨨ   㡰ᔼ�矄ᨨ  ᨨ� ᨨ  ᨨᨨ  鼀矄ᆠ�矄ᨨ矄��ᨨ   ᨨ� ᨨ 泐ᨨ �矄 犨� ᨨ  �ᨨ  矄ᆠᨨ ᨨᨨ    矄 ��盐ᨨ   �� 㡰 矄ᆠ�矄 ᨨ犨盐矄  矄ᨨ犨泐ᨨ   矄ᨨ  �鼀ᨨ矄犨� ᨨ盐矄�� �ᨨ     ᨨ矄矄 ᨨ� �犨� ᨨ盐矄�� �꾀  ᨨ 矄鼀ᨨ �ᆠ鼀  ᨨ矄��ᨨ ᨨ  矄ᆠ犨�ᨨᨨ├�├ ��盐矄矄ᆠ 鼀�ᆠ   ᨨ 犨 ᨨ矄ᆠ㡰 ᲼꾀 桌

꾀矄ᨨ� 矄  矄ᨨ� ᆠ泐� ᨨ �  �ᆠ ��ᨨᆠ  � ᆠ� 犨�  矄鼀� ᨨᆠ�泐 矄 ��盐㡰ᨨ ᨨ犨� ᨨ盐矄�� � ᨨ盐� ᨨ盐 犨ᨨᆠ�鼀鼀 �鼀盐鼀 �� 矄hsph hcylᨨ  � ᆠ�  �ᨨ 泐

hcyl

�矄��

᲼㝐� 꾀҈黨ᔼᔼ桌



҈  㡰 ҈� � �

 ᨨᨨ犨� �ᨨ �矄鼀 ᨨᨨ盐 犨� ᨨ盐矄�� �㡰  矄鼀� ᆠ�    ᨨ鼀 ᨨ� ᨨ   �㡰� �ᨨ

㡰



hsph

㡰 ҈

ᆠ㡰

 �盐矄  ��㡰矄ᨨ� ᆠ泐� ᨨ  �盐矄

R   ���㡰矄ᨨ� 

R  ᔼ  � ᆠ ᆠ矄   矄 ᨨ    ᆠ ᨨ 鼀矄矄 ᨨᨨ鼀ᨨ  � ᆠ� �矄矄鼀  �ᨨᨨ  鼀 �鼀盐鼀 �� 矄 泐ᆠ�鼀�矄 ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰  㡰 ҈҈�䰘 ᆠ㡰 ҈҈� 㡰  꾀 ᨨ鼀ᨨ� ᨨ盐矄矄ᨨ� ᆠ泐� �ᆠᨨᨨ  �盐矄  鼀矄矄 㝐 �矄 盐  ᨨ   ᆠ�ᆠ├ �ᆠ  泐  ᨨ� ᨨ  ᨨᆠ 꾀矄矄盐鼀� � ᨨ� � 犨� ᨨ盐 矄�� �  �盐 ᆠᆠ�ᨨ  ᨨ  ᆠ泐�  �矄 ᲼㝐� ҈ ҈黨ᔼ桌

矄  ᨨ  �盐矄

x㦨

x㦨�ᆠ鼀

㡰

x㦨䰘�ᆠ鼀

�

㡰

x㦨

ᆠ㡰

x㦨

x㦨�ᆠ鼀

x㦨

㡰

x㦨҈ᆠ鼀



  㡰  鼀 㡰 鼀 ᆠ㡰  鼀 㡰 鼀 꾀ᨨ�矄鼀 泐ᨨ� � �ᨨ� 犨ᨨᆠᨨ 矄 � �ᆠ矄졠ᔼ�矄├ᨨ 犨ᨨ�矄꾀 ᔴ犨 �ᆠ  ᆠ  矄泐鼀鼀�ᆠ泐 矄 ��盐㡰 犨�  �矄  �矄  �ᆠ盐ᨨᔴ �矄ᆠ 졠 ᆠ ᨨ � 

WWW.JEEBOOKS.IN

P-63

System of Particles and Rotational Motion

sufficiently high so that the block does not slide before toppling, the minimum force required to topple the block is [2000S] (a) infinitesimal P F (b) mg/4 M L (c) mg/2

joining AB and Cd (see figure). It is given a light push so that it starts rolling with its centre O moving parallel to CD in the direction shown. As it moves, the roller will tend to: [Main 2016] B

D

(d)

O

2 A

7.

C

(a) go straight. (b) turn left and right alternately. (c) turn left. (d) turn right. A loop of radius r and mass m rotating with an angular velocity w0 is placed on a rough horizontal surface. The initial velocity of the centre of the hoop is zero.What will be the velocity of the centre of the hoop when it ceases to slip ? [Masin 2013]

mg(1 - m) Integer Value Answer

12. Two identical uniform discs roll without slipping on two different surfaces AB and CD (see figure) starting at A and C with linear speeds v1 and v2, respectively, and always remain in contact with the surfaces. If they reach B and D with the same linear speed and v1 = 3 m/s then v2 in m/s is [Adv. 2015] (g = 10 m/s2) A

v1 = 3m/s 30m

rw0 rw0 rw0 (b) (c) (d) rw0 3 4 2 A small object of uniform density rolls up a curved surface with an initial velocity v. It reaches up to a maximum height 3v 2 of with respect to the initial position. The object is 4g [2007]

B

(a) 8.

v

9.

10.

11.

(a) ring (b) solid sphere (c) hollow sphere (d) disc A disc is rolling without slipping with angular velocity w. P and Q are two points equidistant from the centre C. The order of magnitude of velocity is [2004S] (a) vQ > vC > vP (b) vP > vC > vQ C P (c) vP = vC , vQ = vC/2 Q (d) vP < vC > vQ A cylinder rolls up an inclined plane, reaches some height, and then rolls down (without slipping throughout these motions). The directions of the frictional force acting on the cylinder are [2002S] (a) up the incline while ascending and down the incline descending (b) up the incline while ascending as well as descending (c) down the incline while ascending and up the incline while descending (d) down the incline while ascending as well as descending. A cubical block of side L rests on a rough horizontal surface with coefficient of friction m . A horizontal force F is applied on the block as shown. If the coefficient of friction is

C

v2 27m D

13. A boy is pushing a ring of mass 2 kg and radius 0.5 m with a stick as shown in the figure. The stick applies a force of 2N on the ring and rolls it without slipping with an acceleration of 0.3 m/s2. The coefficient of friction between the ground and the ring is large enough that rolling always occurs and the coefficient of friction between the stick and the ring is (P/10). The value of P is [2011] 3

Numeric Answer

14. Consider a uniform cubical box of side a on a rough floor that is to be moved by applying minimum possible force F at a point b above its centre of mass (see figure). If the coefficient of friction is m = 0.4, the maximum possible value b of 100 × for box not to topple before moving is a ________. [Main 7 Jan. 2020 II]

WWW.JEEBOOKS.IN

EBD_8341 P-64

҈�

Physics 

꾀� �  �矄ᆠ� ��泐矄矄� 泐矄�   ᨨᨨ  � ᆠ�   犨 �ᆠ 鼀├矄  � 犨�   ᨨ� ᨨ  泐矄ᨨᨨ犨� ᨨ盐矄�� �  矄鼀� 矄 ᨨ �鼀ᨨ � 矄 ᨨ矄 ᔼ  �鼀 �  ᆠ 犨   � ᆠ � �   � ᨨ盐  �矄   㡰 ⏌ ҈ 矄    �� ᨨ  ᨨᨨ  � ᆠ�   � 鼀矄�矄힘힘힘힘힘힘힘힘힘힘 ├g㦨҈鼀矄

 w

w⏌    O

 

x

᲼꾀 ҈桌 5 ҈

꾀� �ᨨ 鼀矄矄├�  �盐矄҈鼀 矄ᨨ� ᆠ泐�  ᨨ 鼀矄矄├� ᨨ  矄鼀 �盐矄��  矄鼀 ├� �ᆠ  �泐  矄  矄�鼀盐 ᨨ盐矄泐 ᨨ    ᨨ� ᨨ 矄盐 ᆠ矄盐ᆠ   泐�� ᨨᨨ矄矄ᨨᨨ 矄 矄 ᨨ犨 矄犨犨 �ᆠ �矄 矄鼀 �矄 ᆠ ᨨ鼀  � �  ᆠ泐�  ᨨ� � �ᆠ�ᨨ � ᨨ ᆠ矄矄 �矄 ���� ᆠ泐� 犨�ᆠ  犨 �矄 ᲼҈黨黨㜠㝐├矄桌 6

҈䰘

㡰  ᨨ� O 矄� ᨨᆠ�泐 w iˆ

True / False

҈黨

MCQs with One or More than One Correct Answer

꾀犨 ᨨ  �盐矄  鼀矄矄㝐�矄ᆠ  ᨨᨨ鼀ᨨ  �  矄ᨨ  ��  矄矄 ᨨ犨 �   ��盐꾀ᆠᨨ 矄  ᨨᆠ�矄ᆠᨨ � 盐ᨨ盐矄泐� ᨨ  矄盐 ᆠᨨ  犨  矄ᨨ �盐矄ᆠ�鼀矄 矄犨� ᨨ盐矄�� �ᔴᨨ 矄�   ᨨ⼄盐tᨨ盐  �矄 ᨨ鼀ᨨ  ᨨ   矄矄� �  ᨨ盐�    ᨨ�  턼 ␔ �ᆠ  ᨨ    ᨨᨨ犨� � ᲼꾀 ҈䰘桌 ᨨ�ᨨ 矄�矄⏌ᆠᨨᆠ䁸 和

 턼

 

҈҈  Rwiˆ + Rwkˆ    ҈  Rwkˆ ᆠ㡰  ᨨ� P 矄� ᨨᆠ�泐 Rwiˆ   㡰  ᨨ� P 矄� ᨨᆠ�泐 æ ö ˆ ˆ ҈ çè  ÷ø Rwi + Rwk   꾀矄 �矄ᨨ� �犨� ᨨ盐矄�� �ᨨ  �   ᨨ� ᨨ   矄盐 ᆠᔼ   ��盐꾀�矄 ᨨ� ᨨ ᆠᨨ ᆠ�矄  ᆠ ᨨ  矄  ᔴ�矄�矄ᨨ鼀ᨨ矄ᨨ�    ᲼黨桌 r r r r C 㡰 VC - VA =  (VB - VC ) r r r r 㡰 VC - VB = VB - VA  B r r r r ᆠ㡰 VC - VA =  VB - VC r r r 㡰 VC - VA =  VB A 꾀矄ᨨ� ᆠ泐� �矄ᨨ� � ᨨ犨 ᨨ盐� � ᆠ�   ᨨ � ᆠ� �ᨨ q 

᲼㜠�㝐҈桌 㡰  �ᆠ�ᨨ  ᨨᆠ�矄 �矄矄�� 㡰  �ᆠ�ᨨ  ᨨᆠ�矄 ᆠ矄矄�泐ᆠ  �� � ᆠ㡰  �ᆠ�ᨨ  ᨨᆠ 犨� �  ᨨ�ᨨ  盐 �   矄�ᨨ

㡰  �ᆠ�ᨨ  ᨨᆠ�矄 盐ᆠ � q�矄 盐ᆠ

㡰  ᨨ� P 矄� ᨨᆠ�泐

9 㡰

҈

ᔼ   ᨨᆠ�矄� ᨨ�  � �泐 

ᆠ矄矄ᆠᨨ � 盐ᨨ盐矄泐矄 犨 ᆠ�鼀矄 㡰 ᔼ   ᨨᆠ�矄�  ᨨ鼀ᨨ ᆠ�ᆠ盐鼀  ᆠ ᨨ�   t�矄ᆠᨨ 矄  ᆠ㡰 ᔼ   ᨨᆠ�矄�  ᨨ鼀ᨨ ᆠ�ᆠ盐鼀  ᆠ ᨨ�   t�矄 ᨨ 㡰 ᔼ   ᨨᆠ�矄�  � �泐ᨨ� 和 

t ¹ 盐 犨  ᆠ�鼀矄 矄

 ��盐矄 ᨨ犨矄矄泐矄鼀ᆠᨨ 矄�矄� �ᨨ  �㡰� �ᨨ ᨨ盐  �盐矄Rᨨ� �ᆠᨨᆠ├犨�矄犨� ᨨ盐矄�� �ᨨ  ᨨ� ᨨ  矄盐 ᆠ犨�  �盐矄 w   ��㡰 �

 �矄ᆠᨨ  �盐矄 Rᨨ� � �㜠ᆠᨨᆠ├犨�矄犨�  �盐矄 w⏌  � �  �矄ᆠ矄 泐 �ᆠ�ᨨ 矄矄� �矄

ᨨ� Pᨨ  �

 �矄ᆠ�矄 �矄 ᆠR ᨨ鼀  ᨨ��� 犨 OP鼀├矄  �ᨨ  犨�   ᨨ� ᨨ 

  犨�  矄ᆠ ᨨ   ᨨ� ᨨ  矄盐 ᆠ ᲼҈桌

Assertion and Reason Type Questions

҈ 和T꾀TE㝐ENT㜠҈ 犨ᨨᆠ泐� 矄ᨨ  ᨨᨨ犨 鼀㡰  ᨨ 矄ᨨ�  犨ᨨᨨ 㡰犨�  矄鼀鼀矄矄 �  �ᆠ �鼀 矄�ᨨ 矄 矄�鼀盐 ᨨ盐矄泐ᨨ犨  ᨨᨨ 犨� ᨨ盐 矄�� � ᨨ犨  � ᆠ�    ᨨ鼀 矄鼀 ��   ᨨᨨ犨ᆠ泐� 犨�ᆠ  ᨨᨨ鼀ᨨ  � ᆠ�    �矄 和T꾀TE㝐ENT㜠泐  � ᆠ�ᨨ ᆠᨨ 矄�ᨨ  ᨨ  �泐 ᨨ├� �ᆠ ��矄ᨨ ᨨ  ᆠ泐� 矄 �  �ᆠ犨   泐ᆠ  ᨨᨨ鼀ᨨ  � ᆠ� ᲼桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐

WWW.JEEBOOKS.IN

P-65

System of Particles and Rotational Motion



m

F



10 Subjective Problems

㡰  ᆠᆠ�ᨨ 矄ᨨ    ├  ᆠ ᨨ M҈ 鼀矄矄ᨨ  ᆠ泐�  㡰  鼀� �盐 矄  �ᆠ�ᨨ 矄ᨨ  �ᆠ�ᨨ  ᨨᆠ矄 ᆠᨨ ᆠ ᨨ� 矄

꾀鼀 盐矄 矄ᆠ泐� ᨨ 鼀矄矄m҈犨�   ᨨ   ├ᨨ 鼀矄矄m矄矄 ᨨ犨 �  ��盐 �  ᨨ矄�� �  泐ᆠᨨ ᆠ  ᨨ� ᨨ  ᆠᨨ鼀ᨨ  ᨨ   ᨨᆠ � 泐 鼀 �矄F ᲼҈黨黨黨㜠҈㝐├矄桌

Topic-6 : Miscellaneous (Mixed Concepts) Problems 1 ҈

ᆠᨨ 矄   �盐 ᆠᆠ�ᨨ  a  ᔼ    ᆠᨨ �ᆠ�  ᨨ �ᆠ�ᨨ 犨  ᨨ    �矄 m  ��泐�矄

�ᆠ    �鼀 犨 �ᆠ   矄矄矄�� � �矄 ᲼和桌

MCQs with One Correct Answer

꾀 ᨨᨨᨨ  �盐矄R�矄├ᨨ  ᨨᨨ  �盐矄r r < R㡰 鼀 ᨨ  ├├ ᨨ� ᨨ 泐졠  ᨨ   ├�矄

ᨨ犨�  矄ᨨ ��矄� 鼀├� �  �q ᨨ鼀  ᨨ� ᨨ 矄矄 ᨨ犨 �   ��盐ᨨ犨 鼀 �鼀盐鼀 盐ᨨ q矄ᨨ   ᨨᨨ ᨨ矄 ᨨ矄ᨨ� � ᨨ犨

  ├矄�矄 �矄 ��盐�矄矄ᆠ 鼀�ᆠ  ᨨ 犨 ᨨ 矄ᆠ㡰 ᲼꾀 桌 Plank

R

a

L

r

q

V

㡰 矄� q =



�



w

v® O 

r t 

r t

㡰

O

T

㡰

t



O

䰘

T

t

r t 

r t ᆠ㡰

졠

t



 O

t

T T 꾀ᨨ � ᨨ� ᨨ ᨨ  矄 犨 �ᆠ ᆠ 矄� ᨨ ��矄  �  � ��泐ᆠ  �矄 ᆠL ᨨ鼀ᨨ  A ᨨ  ᨨ  ᨨ �矄矄�  �盐鼀ᨨ�ᨨ ᨨ盐A犨�

҈  㡰� � �矄�鼀 m ⏌ a  㡰 m ⏌ a  ᆠ㡰 ma 꾀ᆠ盐�ᆠᨨᆠ├ᨨ 矄� �矄鼀ᨨ� �犨� ᨨᆠ�泐Vᨨ  ᨨ� ᨨ 矄鼀ᨨᨨ  矄矄 ᨨ犨 �  ��盐ᔼ �矄� � ᨨ� O  �盐矄 ᨨ  ᨨᆠ├ � �矄O�矄 ᲼҈黨黨黨和㜠㝐├矄桌 a 㡰 V⏌ a㡰 㡰 V⏌ a㡰 M 㡰



r r 㡰  q = R R r r ᆠ㡰 矄� q = 㡰 ᆠᨨ矄 q = R R 꾀 � 盐 � ᨨ鼀ᨨ �ᨨ O�矄ᨨ� ��   ᨨ� ᨨ   犨� ᆠᨨ 矄  �盐矄 w矄矄 ᨨ犨 �   ��盐 꾀�鼀t㦨矄鼀� 矄ᆠ矄矄 ᨨ鼀O 鼀ᨨ矄犨� ᆠᨨ 矄 矄 v犨� 矄ᆠᨨ ᨨ ᨨ犨 矄 ᨨ   ᔼᆠ 矄  ᨨ  ᨨ t = T 矄ᨨ矄   �盐矄 ᨨ  矄泐矄鼀鼀� 矄w  ᨨ盐� ᨨ盐  鼀� �盐 ᨨ  ᨨ⼄盐 ( rt ) ᨨ盐 O 矄  盐 ᆠ�ᨨ  ᨨ �鼀�矄矄矄  泐犨 �ᆠ ᨨ䁸 ᲼҈桌  z

B

A

ᆠ㡰 V ⏌ a 㡰 㡰 ᨨ O 꾀矄鼀ᨨᨨ 矄 꾀�矄鼀ᨨ� �ᨨ  �ᆠ�ᨨ 矄矄 ᨨ� ᨨ   犨�  �盐矄 w ᆠ ᨨ 鼀矄矄ᨨᆠ�泐u ᔼᆠᨨ� 矄矄�ᆠ泐   ᨨ 犨�  �  �ᆠ矄  矄�ᆠ �ᆠ�ᨨ 泐犨 꾀  ᆠᨨ�矄�ᨨ   � �盐矄 矄w꾀 w矄ᆠ�泐 

᲼҈黨黨黨和㜠㝐├矄桌 㡰 w꾀w 㡰 w꾀㦨w ᆠ㡰 w꾀㦨w 㡰 w㦨w

犨ᨨᨨ� 鼀矄矄矄ᨨ ├� 䰘├� �    矄 ᨨ ᨨ ᨨ  � ҈鼀 ᨨ  ����鼀矄矄 ᨨ �矄 矄ᨨ� �ᨨ盐  �矄 �ᆠ盐ᨨ�矄 � 犨� 盐 � ᨨ鼀 �盐矄  ᨨ� ᨨ  ᨨ  ᨨ盐� 犨 �ᆠ   �矄矄 ᨨ盐 矄矄� ᨨ   犨ᨨ├⼄盐� ᨨᨨ�ᨨ ᨨ  ᨨ �矄鼀� �鼀盐鼀�矄ᨨᆠ  �矄 ᆠ ᨨ ᲼҈黨黨�和桌 㡰 m ᨨ鼀鼀矄矄ᨨ ├� 㡰 䰘m ᨨ鼀鼀矄矄ᨨ 䰘├� ᆠ㡰 黨m ᨨ鼀鼀矄矄ᨨ ├� 㡰 黨m ᨨ鼀鼀矄矄ᨨ 䰘├� 꾀ᆠ�矄鼀ᨨ� �� ᆠ�ᆠ盐 ᨨ� ᨨ ᆠ├ᨨ  �盐矄҈鼀 犨�   ᆠᨨ 矄  矄  ᨨ  ҈ 鼀⏌矄꾀  盐盐鼀 ᨨ �矄 矄盐矄   ᨨ鼀 ᨨᨨ ᨨ  ᆠ泐�� ��� ᨨ ᨨ  � ҈鼀  �鼀 泐 ᨨ 犨� ᆠ├�矄 ᲼҈黨黨㜠㝐├桌 㡰 ᨨ 㡰  ᆠ㡰 � 㡰  꾀 盐 ᨨ   �  L �矄 �  ᆠᨨ鼀泐犨�  

� ᆠᨨ鼀矄矄��⼄盐� ᨨ 鼀矄矄M   ᆠᨨ矄  ᨨ     矄 盐�矄  ᨨ �  ᨨ� ᨨ  ᨨ盐 ᨨ ᨨ �矄 矄犨� 盐 � ᨨ鼀 �盐ᨨᆠ�泐 w   ᨨᆠ  泐 �⼄盐�  ᨨ  �矄 ᲼҈黨黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-66

Physics

㡰 ᆠ㡰 2 黨

M w L 㡰  M w L 㡰  Integer Value Answer

ᆠ㡰

M w L

犨�

 

Mw L 

F

졠 矄ᆠᨨ  泐� �  ᨨᆠ矄  �盐矄 ᨨ   �矄ᆠ�  矄҈�矄 ᲼꾀 ҈桌

҈

꾀盐 � ᨨ鼀ᆠ盐ᨨ 矄�  a 鼀矄矄m矄矄ᨨ ᨨ盐� ᨨ� ᨨ 꾀 ᨨ� ᨨ  ᨨᆠF�矄�  ᨨ鼀ᨨ ᨨ ᨨ   ᆠ矄ᨨ�  �矄 �ᆠ泐ᨨ ᆠ  ᨨ   ᆠ �� a⏌ᨨ 矄 鼀� �鼀盐鼀 盐ᨨ F ᨨ犨 �ᆠ  ᆠ盐�� 矄ᨨ�ᨨ盐  � �矄 꾀矄矄盐鼀  ᆠ盐 ᨨ矄 ᨨ矄� 㡰 ᲼҈黨㜠㝐├矄桌 5

҈҈

True / False

꾀� �盐  ᨨ  盐 � ᨨ鼀  �ᆠ├ 矄矄   矄�泐�矄鼀  ᨨ ᨨ ᨨ盐    �矄  �ᆠ盐 ᨨ     ᨨ      㡰 矄矄� � A B C  ᨨ盐� A 㡰矄矄� � ᨨ盐� B泐 �ᆠ�ᨨ ᨨ F  矄鼀 ᨨᆠFC 鼀� ᨨ� ᨨ AB㡰矄矄 ᨨ犨 �   ��盐  �盐ᆠᆠ�ᨨ � ᨨ  ᆠ矄矄犨�  矄鼀 ᲼҈黨�㜠㝐├矄桌 6

҈

Fill in the Blanks

MCQs with One or More than One Correct Answer

꾀 �  盐 � ᨨ鼀ᨨ ᨨ 鼀矄矄M  � L�矄  �ᆠᨨ  ᨨᨨ犨� � �ᆠ�ᨨ  ᨨ �矄矄 ᨨ鼀 矄 矄ᨨ  � 矄 泐ᨨ� � ᨨ盐 �矄 ᆠᨨ ᆠ㜠 ᨨ�  犨�    ᨨᨨ 犨� ᨨ盐 矄�� � ␔ �ᆠ  ᨨ    ᨨᨨ犨� �矄鼀  矄㡰�矄⏌ᆠᨨᆠ犨   ᨨ 鼀├矄   � 犨� �ᆠ䁸 ᲼꾀 ҈黨桌 ᲼g�矄 ᆠᆠ�ᨨ  盐ᨨ��泐桌 g L

㡰

 �盐矄 ᨨ  ᨨ 犨�

㡰

 �ᆠᆠᆠ�ᨨ ᨨ  ᨨ 矄ᆠ ᨨ 鼀矄矄 g 犨� 

Mg ҈

g L ҈ 犨ᨨ矄ᨨ� ᆠ泐� 矄P Qᨨ 矄鼀鼀矄矄 矄鼀 �盐矄 矄ᨨ� � ᨨ犨  �  � ᆠ�    ᨨ鼀 矄鼀 ��  矄鼀�鼀ᔴ泐� P 矄鼀ᨨ矄ᨨ �矄鼀矄矄 ᆠᨨ ᆠ   �矄矄盐 ᆠ犨 �Q 矄鼀ᨨ矄ᨨ �矄鼀矄矄 ᆠᨨ ᆠ       �矄 ␔ �ᆠ  矄鼀  矄㡰 �矄 㡰 ᆠᨨᆠ䁸 ᲼҈桌



꾀盐 � ᨨ鼀ᆠ�ᆠ盐 �矄ᆠᨨ 鼀矄矄҈�├�  �盐矄�鼀�矄 � ��泐矄ᨨ  ᨨ� ᨨ  �ᆠ�ᨨ 矄矄矄盐 ᆠ  F ᨨᆠ矄ᨨ ⼄盐鼀� �盐 F㦨� X � 矄�鼀盐 ᨨ盐矄泐ᨨ �   矄� 矄ᨨ  ⼄盐�� � O XYZ犨� �矄�ᆠ矄ᨨ  �鼀 F Y Z ᨨ   �矄ᆠ 矄 ��盐㡰

4

 ᨨ鼀ᆠ�ᨨ  ᨨᆠ ᨨ鼀  ᨨᨨᨨ  ᨨ

 �盐ᆠᆠ�ᨨ ᨨ  ᨨ 犨�

㡰 ᨨ ᆠ泐� 矄P Qᆠ  �ᨨ盐  矄鼀 �鼀 㡰 ᔴ泐� 矄P 矄�� ᆠᆠ�ᨨ   ᆠ泐�  Q ᆠ㡰 ᨨ  ᆠ泐� 矄 ᆠ    �ᨨ盐  犨�  矄鼀  矄�ᨨ ├� �ᆠ �泐 㡰 ᔴ泐� Qᆠ 矄 �ᨨ盐 犨� � �盐 矄  ҈ 꾀 � � �ᨨ 鼀矄矄├�  �盐矄�鼀�矄ᨨ� �犨� ᨨ盐 ᨨ  ᨨ� ᨨ  犨� ᨨᆠ�泐҈鼀⏌矄꾀矄鼀ᨨ 鼀矄矄҈├�鼀ᨨ� �犨� ᨨᆠ�泐鼀⏌矄�  ᨨᨨ矄� �ᆠ�ᨨ  �矄  � �   ��  ᨨ 䰘� 鼀  �ᨨ矄 �ᆠ泐盐犨� ᨨᆠ�泐҈鼀⏌矄ᔼ鼀鼀 �泐   ᆠᨨ�矄�ᨨ

 ᲼҈҈桌

㡰  � � 矄盐ᨨ�ᨨ ᨨ盐�矄矄�ᨨ 泐ᔴ㝐 㡰  � �ᆠᨨ鼀矄ᨨᆠᨨ鼀矄ᨨ ᆠ㡰 �ᆠ�ᨨ 犨  � �  �ᨨ盐 �矄ᨨ   㡰  �矄 ᨨ �ᆠ�ᨨ 犨  � �  �ᨨ盐  ҈� 꾀盐 � ᨨ鼀ᨨ  � a 鼀矄矄m�矄ᨨ 矄鼀ᨨᨨ ᨨ� ᨨ  犨ᨨᨨ� 鼀矄矄矄m m鼀ᨨ� ��

 矄鼀 ᨨ� ᨨ  犨� 矄 v v矄ᆠ�泐 矄�├ ᲼矄矄 ᨨ犨 �   ��桌 矄�ᆠ├ᨨ   ᆠᨨ�矄�ᨨ  ᨨ� � �盐ᨨᆠ�泐 ᨨ盐 ᆠ  ᨨ 鼀矄矄㡰ᨨ �泐 ᆠ ᨨ 鼀矄矄ᨨᆠ�泐泐wE  vc矄ᆠ�泐犨  ᆠᨨ�矄�ᨨ ᲼҈黨黨҈㜠㝐├桌 㡰 vc 㦨 m v 㡰 w 㦨  a v �a ᔴ v ᆠ㡰 w = �a 㡰

mv  E= �

a

a

v 鼀m

WWW.JEEBOOKS.IN

P-67

System of Particles and Rotational Motion

7

Match the Following



҈ ᔼ  ᔴᨨ盐鼀 㜠ᔼᨨ犨 ᨨ盐 �   矄ᨨ �ᆠ �� 矄 盐 ᆠ�ᨨ 矄ᨨ �鼀ᔼ  矄 盐 ᆠ�ᨨ 矄a b ᨨ矄��ᆠᨨ 矄 矄ᨨ ᨨ� �鼀 矄�ᨨ 矄 a ¹ bᔼ  ᆠ ᆠ矄  ᨨᆠᆠ� �ᨨ  �ᆠ�矄�  ᨨᨨᆠᨨ 矄�ᔼ ᔴᨨ盐鼀 㜠ᔼᔼ � 泐矄�ᆠ⼄盐 ��矄 r r ᨨ  �ᆠ鼀 �ᨨ   �矄 � 鼀ᨨ鼀 盐鼀  �矄   �盐鼀ᨨ鼀 盐鼀ᨨ盐 ᨨ��� ⧤�矄 ├� �ᆠ  �泐�矄 ᨨ � �泐 쟼�矄 ᨨ �泐 㝐ᆠ ᆠ  � �矄㜠ᔼ犨�  ᨨ矄⼄盐 ��矄� �矄㜠ᔼᔼ 犨 �ᆠ ᆠᨨ 矄  ᨨ  ᲼꾀 ҈桌

턼  和 㡰 㡰 ᆠ㡰 㡰

ᔴᨨ盐鼀 ᔼ r  㡰 = a  �ˆ+ b  ˆ r  㡰 = a ᆠᨨ矄 w �ˆ+ b 矄� w ˆ r  㡰 = a ᆠᨨ矄 w �ˆ+ 矄� w ˆ㡰 r b  㡰 = a �ˆ+   ˆ 



ᔴᨨ盐鼀 ᔼᔼ r  r  ⧤





҈ 

� 쟼 ®҈�錐턼®�錐 ®�錐和®� ®҈�錐턼®�錐 ®�錐和®� ®錐턼®�錐 ®҈錐和®� ®҈�錐턼®�錐 ®�錐和®�

҈䰘 ᔴᨨ盐鼀 㜠ᔼᔼ矄 ᨨ犨矄 �矄泐矄鼀矄� 犨 �ᆠ 犨ᨨᨨᆠ矄 矄 Ӹ꾀矄ᨨ� ᆠ ᆠ矄ᨨ� �矄矄 ᨨ犨 ᔴᨨ盐鼀 㜠ᔼ ��矄矄ᨨ鼀矄鼀 矄ᨨ盐 ⏌ᨨӸ㝐ᆠ  矄矄鼀 矄ᨨ ᨨ�矄泐矄鼀 矄㡰 ᨨ鼀ᔴᨨ盐鼀 ᔼᔼ᲼黨桌 ᔴᨨ盐鼀 㜠ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰  ᨨᆠ  泐ᨨ Ӹ 矄 㡰 Ӹ  鼀� �盐 Mg. 

ᨨᆠ├Ӹᨨ 鼀矄矄M  ᨨ  �  � ᆠ�   矄� 矄ᨨ �犨�  ᆠᨨ 矄  ᨨᆠ�泐 㡰 ���ᨨ ᨨ � �泐ᨨ �矄ᆠᨨ � 盐ᨨ盐矄泐� ᆠ矄� �

⼄㡰



 Ӹ 

犨ᨨ� �鼀� 矄Ӹ ᆠ ᨨ 鼀矄矄M, ├�  �ᆠ�ᨨ 矄矄�ᆠ 矄�ᆠ矄 矄ᨨ  泐ᆠ ᨨ Ӹ矄矄ᨨ  矄   �矄�  � �  ⼄盐���盐鼀 �矄   ᨨ鼀ᨨ矄ᨨ�  ᨨ  矄 ᨨ    ᆠᨨ鼀鼀ᨨ  �矄ᨨ  犨ᨨ� �矄 犨 ᨨ矄泐矄鼀�矄� �  �矄�ᨨ� �盐 犨� ᆠᨨ 矄 ᨨᆠ�泐 ᔴ㡰 㝐ᆠ  �ᆠ �泐ᨨ  矄泐矄鼀 졔Ӹ�矄ᆠᨨ � 盐ᨨ盐矄泐 ᆠ矄� �

㡰 ᨨ⼄盐ᨨ  犨�� ᨨ Ӹᨨ盐 ᨨ� �矄 ᨨ

㡰 꾀盐泐Ӹᨨ 鼀矄矄m0 �矄 �  ᨨ ᨨ盐�  ᆠ鼀꾀ᨨᆠ├ᨨ 鼀矄矄㝐  �矄 ᨨ鼀矄� �  �ᨨ矄 ᨨ  盐泐  �矄 �    ᨨ�  ᨨ    犨 ᨨ矄泐矄鼀�矄├� �  �矄�ᨨ� � ᨨ犨 犨� ᆠᨨ 矄 ᨨᆠ�泐



Ӹ 

矄㡰 Ӹ

 

꾀矄 Ӹᨨ 鼀矄矄M�矄盐�  ᨨ 㜠�矄ᆠᨨ盐矄�⼄盐� ├� ᆠᨨ �  矄 矄 �矄矄  �鼀ᨨ矄 ᨨ犨 �  �⼄盐�  㡰 꾀矄 Ӹᨨ 鼀矄矄M�矄 � �犨� �矄鼀�  ᨨᆠ�泐 �  �矄ᆠᨨ盐矄 �⼄盐�  ├ �  ᆠᨨ � 

Ӹ

 

WWW.JEEBOOKS.IN

EBD_8341 P-68

Physics

8

Comprehension Based Questions

Passage 1 One twirls a circular ring (of mass M and radius R) near the tip of one's finger as shown in Figure 1. In the process the finger never loses contact with the inner rim of the ring. The finger traces out the surface of a cone, shown by the dotted line. The radius of the path traced out by the point where the ring and the finger is in contact is r. The finger rotates with an angular velocity w0. The rotating ring rolls without slipping on the outside of a smaller circle described by the point where the ring and the finger is in contact (Figure 2). The coefficient of friction between the ring and the finger is m and the acceleration due to gravity is g. [Adv. 2017]

Now consider two similar systems as shown in the figure: Case (a) the disc with its face vertical and parallel to x-z plane; Case (b) the disc with its face making an angle of 45° with x-y plane and its horizontal diameter parallel to x-axis. In both the cases, the disc is welded at point P, and the systems are rotated with constant angular speed w about the z-axis. z

Q

w

y

P x

Case (a)

z

w

Q

45°

R x

r R Figure 1

Figure 2

18.

19.

The total kinetic energy of the ring is 1 Mw02 (R - r) 2 (a) (b) Mw02 R 2 2 3 Mw02 (R - r)2 (c) (d) Mw02 (R - r) 2 2 The minimum value of w0 below which the ring will drop down is (a)

g m(R - r)

(c)

3g 2m(R - r)

y

P

(b)

2g m(R - r)

(d)

g 2m(R - r)

Passage 2 The general motion of a rigid body can be considered to be a combination of (i) a motion of its centre of mass about an axis, and (ii) its motion about an instantaneous axis passing through the centre of mass. These axes need not be stationary. Consider, for example, a thin uniform disc welded (rigidly fixed) horizontally at its rim to a massless, stick, as shown in the figure. When the disc-stick system is rotated about the origin on a horizontal frictionless plane with angular speed w, the motion at any instant can be taken as a combination of (i) a rotation of the centre of mass of the disc about the z-axis and (ii) a rotation of the disc through an instantaneous vertical axis passing through its centre of mass (as is seen from the changed orientation of points P and Q). Both these motions have the same angular speed w in this case [2012]

Case (b)

20. Which of the following statements about the instantaneous axis (passing through the centre of mass) is correct? (a) It is vertical for both the cases (a) and (b) (b) It is vertical for case (a); and is at 45° to the x-z plane and lies in the plane of the disc for case (b). (c) It is horizontal for case (a); and is at 45° to the x-z plane and is normal to the plane of the disc for case (b). (d) It is vertical for case (a); and is 45° to the x-z plane and is normal to the plane of the disc for case (b). 21. Which of the following statements regarding the angular speed about the instantaneous axis (passing through the centre of mass) is correct?

2w for both the cases

(a) It is

(b) It is w for case (a); and w/ 2 for case (b) (c) It is w for case (a); and 2w for case (b) (d) It is w for both the cases. Passage 3 A uniform thin cylindrical disk of mass M and radius R is attached to y two identical massless springs of spring constant k which are fixed 2d to the wall as shown in the figure. The springs are attached to the axle of the disk symmetrically on either side at a distance d from its centre. The axle is massless and both the d d springs and the axle are in R V0 horizontal plane. x The unstretched length of each spring is L. The disk is initially at its equilibrium position with its centre of mass (CM) at a distance L from the wall. The disk rolls without slipping with r velocity V = V ˆi . The coefficient of friction is µ. [2008] 0

0

22. The net external force acting on the disk when its centre of mass is at displacement x with respect to its equilibrium position is (a) – kx (b) – 2kx (c) – 2kx/3 (d) – 4kx/3

WWW.JEEBOOKS.IN

P-69

System of Particles and Rotational Motion





ᆠ ᨨ 鼀矄矄ᨨ   �矄├盐 �ᨨ矄矄�鼀 鼀ᨨ �ᆠ 鼀ᨨ�ᨨ 犨�  �盐 ⼄盐 ᆠ泐w⼄盐ᨨ ├ ├ ├ ├ 㡰 ᆠ㡰 㡰 㝐 㝐 㝐 㝐

鼀 �鼀盐鼀盐ᨨ  ᨨ犨 �ᆠ   �矄├犨�ᨨ犨� ᨨ盐 矄�� ��矄



㡰 

㡰

m�

㝐 ├

㡰

m�

㝐 㝐 �㝐  ᆠ㡰 m�  㡰 m� ├ ├ ├

矄矄�

犨ᨨ �矄ᆠ矄A B鼀ᨨ盐  ᆠᨨ �泐ᨨ �ᆠ   �矄ᆠ矄 鼀ᨨ鼀 矄ᨨ � �I I矄ᆠ�泐ᨨ盐  ᆠᨨ鼀鼀ᨨ  �矄�矄ᆠA�矄�鼀  � �� �盐ᨨᆠ�泐w 盐矄� �  �ᨨ � �泐ᨨ 矄� �ᆠᨨ鼀矄矄 泐 �矄 ᆠx�矄ᆠB�矄�鼀   �盐ᨨᆠ�泐w泐矄� � � � 矄鼀矄� �ᆠᨨ 矄  ᆠᨨ鼀矄矄 泐 �矄 ᆠ xᨨ   �矄ᆠ矄ᨨ�  ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  � ᨨ矄矄ᨨ ├� �ᆠ �泐�  ᨨᨨᆠ矄矄�矄᲼䰘桌 I w I w I w I w 㡰 ᆠ㡰 㡰     ␔   �矄ᆠB �矄ᨨ盐� � ᆠᨨ ᆠ犨�  �矄ᆠA 泐ᆠ⼄盐� ᆠᨨ鼀鼀ᨨ  �盐ᨨᆠ�泐� �鼀t � �ᆠ�ᨨ  ᨨ⼄盐ᨨ ᨨ  �矄ᆠ泐 ᨨ  盐� � �矄�ᨨ �矄 ᲼䰘桌  Iw I w 黨 I w 黨I w 㡰  㡰 ᆠ㡰 㡰 t t t t

�ᨨx҈⏌x�矄 ᲼䰘桌 ҈ ҈ 㡰  㡰 ᆠ㡰 㡰   



鼀 

҈ �ᆠ矄AB  Cᆠ ᨨ 鼀矄矄鼀ᆠᨨ

ᆠ ᨨ ᆠ  ᨨ  泐 鼀矄矄矄矄���  ᨨ 矄ᨨ ᨨ鼀 ���  ⼄盐�� �盐ᨨ 泐ᨨ 矄�  l  �矄ᨨ 泐�矄ᆠ ᨨ  ᨨ� ᨨ  �ᆠ�ᨨ 矄矄 x㜠y 㡰 �矄 � � ᨨ � ᨨ� A矄ᨨ �ᆠ 鼀ᨨ犨� ᨨ盐 �ᆠ�ᨨ ᨨ盐  �ᆠ �矄 ᨨ盐� A 矄 ��盐㡰 ᨨ 泐�矄矄� ᨨ ᨨ�ᨨ 鼀ᨨ�ᨨ ᨨ  ᨨ盐A犨� ᆠᨨ 矄  �盐 ᨨᆠ�泐w ᲼㜠�㝐├矄桌 泐



w

㡰 

䰘

10 Subjective Problems 

黨



꾀 ᆠ �盐  ᨨ  鼀矄矄M  �鼀 矄�ᨨ

a맔b�矄  �  ᨨ� ᨨ  ᨨ矄��ᨨ  泐矄�├� �

 矄鼀矄 ᆠ ᨨ 鼀矄矄 m㡰  盐 �   矄ᆠᨨ  

矄矄�├� ��  矄     ��ᨨ ᨨ  

ᆠᨨ�矄�ᨨ ᨨ  矄犨�  �矄矄�ᆠ␔ �矄v䁸 ᲼㜠㝐桌 ෌� n㦨҈M 㦨├�m 㦨҈├�錐b㦨m錐a㦨҈鼀錐 g㦨҈鼀⏌矄㡰

犨ᨨ�  �ᆠ 矄ᆠ ᨨ 鼀矄矄 M  � L矄� �ᨨ    ᨨ盐�  ᨨ� ᨨ 矄盐 ᆠ矄矄 ᨨ犨

 鼀 �    ��盐꾀ᨨᆠ├ᨨ 鼀矄矄m q q  �矄 ᨨ鼀P 꾀  ᔼ  矄泐矄鼀�矄� ⼄盐���盐鼀 �  鼀� �盐    �ᆠ�ᨨ ᨨ  �ᆠ�ᨨ  ᨨᆠA  B ᲼�㜠㝐├矄桌 꾀 犨ᨨᨨ   ᨨ� ᨨ  鼀矄矄 M    �  L �矄  � � 泐  �ᆠ�ᨨ 矄矄 �O꾀盐ᨨ 鼀矄矄m 矄�├矄犨� ᨨᆠ�泐 v   矄�ᆠ├矄 ᨨ � �   �盐 ᨨᆠ�泐ᨨ   矄泐矄鼀 �鼀鼀 �泐  ᆠᨨ�矄�ᨨ ᨨ盐O᲼�㜠㝐├矄桌

F

l  ᔴ 㡰 �  鼀� �盐 ᨨ   ᨨ� ᨨ  ᨨᆠ  泐  � �ᨨ  ᨨ 泐 㡰 꾀�鼀T犨   矄� BC�矄ᨨ x㜠 �矄 ᨨᆠF�矄� ᨨ Bᨨ �BC 矄矄 ᨨ犨 㡰졠�

  x㜠ᆠᨨ鼀ᨨ       y㜠ᆠᨨ鼀ᨨ   ᨨ    ᨨᆠ   泐  � �ᨨ   ᨨ 泐�鼀鼀 �泐  �鼀T  犨ᨨ 泐 鼀�ᆠ 矄  ᨨ�   A ᨨ� 黨ᨨᨨᆠ ᨨ 꾀鼀� 矄  턼 ᨨ 鼀矄矄├��矄 � �  � AB ᨨ� � � B P  犨ᨨ 泐鼀�ᆠ 矄  � �矄 �ᆠ�ᨨ 矄矄  鼀ᨨ鼀 ᨨ � �ᨨ    鼀� 矄 ᨨ盐  �矄ᨨAB 矄矄� �  ᨨ盐�  �矄 ᆠ  ᨨ  鼀矄矄 �矄 ҈ ├�㜠m 犨ᨨ 盐 ᨨ矄ᆠ矄P Q  �  ᨨ ᨨ ᆠ 鼀�ᆠ �矄 ᆠ�鼀 ᨨ鼀 � AB �矄 �矄 ᆠ�矄ᆠ ᨨ矄 矄ᨨ   ᆠ�ᨨ  盐ᨨ  � �矄ᨨ  鼀� 矄 �矄 ᲼҈㜠҈㝐├矄桌 ᨨ 盐� � �鼀ᆠ ᔼ ��泐 鼀� 矄  �矄ᨨ ᨨ  ᨨ矄ᆠ矄犨� 

 �盐ᨨᆠ�泐҈ ⏌矄 盐 矄ᆠ├ᔼ  �鼀盐矄ᨨ

 矄  盐ᨨᆠ ᨨ矄ᆠ�矄㜠矄 㡰 �  ᨨᆠ�ᨨ ᨨ  ᆠ ᨨ 鼀矄矄ᨨ  鼀�  矄  ᨨ鼀AB 㡰 꾀犨  �盐ᨨᆠ�泐 ᨨ矄 鼀� 矄 ᆠᨨ鼀 ᆠ├   �矄�鼀ᆠ䁸 ᆠ㡰 꾀  ᨨ犨鼀 泐�鼀ᆠ矄 ᨨ矄 鼀� 矄 ᆠᨨ鼀 ᨨ矄䁸

WWW.JEEBOOKS.IN

EBD_8341 P-70





Physics

꾀 盐 � ᨨ鼀 ᆠ�ᆠ盐 A �矄ᆠ 矄 �盐矄R 鼀矄矄m꾀�ᆠ矄ᨨ R ᨨ 鼀矄矄m�矄 �   ᨨ� Aᨨ   �ᨨ C   �矄ᆠ矄矄 ᨨ犨 �

R⏌ ��盐  �矄ᆠᆠ P Q ᨨ 泐ᨨ盐  �   ᨨ� ᨨ ᆠ ᨨ PQ �矄 �矄 ᆠR⏌ ᨨ鼀 ᆠ Cᨨ   �矄ᆠ

� AC�矄 �ᆠ盐ᨨPQ ᔼ ��泐  �矄ᆠ�矄  �ᆠ犨�  ᨨ� A�矄 �� 矄ᨨ矄��ᨨ ᔼ�矄  ᨨ犨 ᨨ 矄ᨨ �矄矄 ᨨ� �ᨨ盐PQ �  � 矄 ᨨ  �ᆠ矄 ᲼҈黨黨㜠㝐├矄桌 �ᆠ 矄�矄ᨨ犨矄ᨨ矄��ᨨ  꾀犨 �ᨨ 鼀矄矄鼀 � �盐ᆠᨨ矄矄㜠矄ᆠ�ᨨ  AB㦨BC 㦨CA㦨R㡰�矄鼀ᨨ� �犨� ᆠᨨ 矄 ᨨᆠ�泐- v�ˆ ᨨ犨 矄 矄 ᨨ  �盐矄R �  ᨨ 矄鼀ᨨᨨ  ᨨ� ᨨ 矄 矄 ᨨ犨 �  ��盐 犨 �鼀├矄 矄�ᆠᆠᨨ�矄�ᨨ

犨�    �  矄  盐 矄ᨨ � 矄鼀 犨� ᨨ盐 泐ᨨ�ᨨ �ᆠ �ᆠ�ᨨ  矄盐ᨨ矄   犨 �鼀� 矄� ᆠᨨ ᆠ犨�  矄  ᨨ泐 矄 ᨨ�鼀Dt 盐� �犨 �ᆠ  矄  矄ᆠᨨ 矄  ᲼҈黨黨㜠㝐├矄桌 ᨨᆠFᨨ  犨 � A

y

R

v

x

�

B

C

㡰 �   ᨨᆠF 矄ᨨ  ᨨ鼀 ᨨᆠN  泐 ᨨ  犨 � 盐� � �鼀D 㡰 h  ᨨ  �ᆠ盐 �矄 ᆠ犨   ᆠ ᨨ 鼀矄矄ᨨ  犨 �  � ᨨ ᆠ�ᨨ ᨨ  �  鼀� �盐 ᨨ  ᨨ⼄盐 盐ᨨ  ᨨ鼀 ᨨᆠNᨨ盐  ᆠ ᨨ  犨 � 盐� �  �  Dt 

犨ᨨ � ᆠ�ᆠ盐 �矄├矄 ᨨ  鼀矄矄  ├�  �盐矄҈ ᆠ鼀 ᆠ   ᨨ�  泐��� 鼀矄矄矄矄 ᨨ  ᨨ  � ᆠ鼀

 �矄ᨨ  ᨨ �矄ᨨ �  �ᆠ盐ᨨ  矄 ᨨ   �矄├ ᨨ盐�  �ᆠ 矄 �矄ᨨᆠ�矄├ᨨ  盐ᆠ├� 矄盐ᆠ 犨泐   �矄ᨨ  ᨨᆠ�矄 ᨨ� ᨨ    �ᆠ盐ᨨ  �ᆠ�ᨨ ᨨ  鼀ᨨ�ᨨ ᨨ   盐ᆠ├ᔼ矄 �ᆠ�ᨨ 犨�   ᨨᨨᨨ  盐ᆠ├�矄� ᨨ盐� 矄ᨨ  ᨨᆠᆠ ᨨᨨ  盐ᆠ├犨� ᨨ盐矄�� �

├x �矄矄  �ᆠ�ᨨ ᨨ 鼀ᨨ�ᨨ ᨨ  盐ᆠ├ z �矄 矄 �ᆠ泐盐犨 矄 �ᆠ�ᨨ ᔼ  盐ᆠ├ 矄

ᆠᆠ�ᨨ ᨨ 黨鼀⏌矄 ᔴᆠ盐 ᲼҈黨黨䰘㜠�㝐├矄桌 �㡰  ᨨᆠᨨ  �ᆠ�ᨨ ᨨ ᆠ  �矄├ ��㡰  鼀� �盐     �ᆠ�ᨨ  ᨨ   �ᆠ�ᨨ  ᨨ⼄盐ᆠ� �ᨨ ᆠ  �矄├ᨨ盐 ᆠ ᨨ 鼀矄矄 Oᨨ  ᨨᆠ쟼 矄矄 ᨨ⼄盐�  ᆠᨨ ᨨ鼀 � 鼀矄ᨨ 盐 �ᆠᨨ矄 �ˆ ˆ   kˆ �  xy z �ᆠ�ᨨ 矄

 꾀ᆠ �盐���  �  ᨨᆠ├ 矄ᨨ � ᨨ� ᨨ  �꾀 矄ᨨ�  ᨨ鼀ᨨ� ᨨ盐矄ᆠ泐� ᨨ  �盐矄R�矄ᆠ  ᨨ� ᨨ 泐 矄�矄 � ᨨ   �矄盐ᆠ    �矄ᨨ   ᆠ泐�    �ᨨ  ᨨᆠ├�  矄鼀�ᆠ  矄 矄 ᨨ犨  �    ��盐 ᨨ犨  �矄矄盐 �ᆠ�  �ᆠ�ᨨ  矄      � 矄ᨨ    泐 矄鼀 �矄ᆠ鼀  ᆠ盐矄矄   ᆠ泐�  ᨨ ᨨ ᨨ     � 犨� ᨨ盐矄�� �鼀�  ᲼҈黨黨�㜠҈㝐├矄桌 㡰   �qᆠ ᨨ盐� 犨 �ᆠ  ᆠ泐� ᨨ矄 ᨨ �矄ᆠᨨ ᆠ犨�   � 㡰  矄 ᨨ  ᆠ ᨨ 鼀矄矄ᨨ  ᆠ泐�  ᨨ � �ᆠᨨ ᆠ犨�   � ᆠ㡰   �ᨨᨨ     矄�ᨨ  ᨨ ᨨ�ᨨ  ├� �ᆠ  ��矄ᨨ  ᆠ泐� 犨  �矄ᆠ ᨨ 鼀矄矄�矄�

ᨨ� ᨨ � 犨�   � 䰘 犨ᨨ盐 � ᨨ鼀 � ᨨ 矄A Bᨨ  �  mᆠ  ᨨ 鼀矄矄矄҈├� ├�  矄ᆠ�泐��� 泐ᨨ�   ᨨ   ᆠᨨ鼀� �ᨨ �矄�ᨨ  ��  P 꾀 矄矄 ᨨ犨 �  ��和盐ᆠ  �ᆠ  泐ᨨ ᨨ盐ᨨ�  P �   �ᆠ  꾀矄鼀 ᨨᆠᨨ 鼀矄矄�├�鼀ᨨ� � ᨨ� ᨨ 泐  �矄 ᨨ犨  ᨨ  ᆠᨨ鼀� �ᨨ   矄�ᆠ├矄ᨨ� ␔   矄 ᨨ盐     ᨨᆠ�泐ᨨ   ᨨᆠ 矄ᨨ     矄泐矄鼀ᆠᨨ盐 盐矄�矄 ᨨ  ᨨ� ᨨ ᨨ矄��ᨨ  ᲼҈黨黨㜠㝐├矄桌  꾀ᨨᆠ├Xᨨ 鼀矄矄�├��矄  泐ᨨ �鼀矄矄矄矄矄� � ᨨ  �ᆠ�ᨨ 矄矄� ᆠ�   ᨨ � ᆠ� �ᨨ  ᨨ  ᨨ� ᨨ   矄� � �矄 犨ᨨ盐  ᨨ   盐 � ᨨ鼀 矄ᨨ� ᆠ泐� �ᆠ 盐鼀Yᨨ 鼀矄矄├� ᨨ  �盐矄m矄 矄 ᨨ犨 �  ��盐  盐鼀�矄��  � �� �盐 ᨨᆠ�泐矄盐ᆠ   ᨨᆠ├X矄矄鼀ᨨ� �盐   ᲼҈黨黨㜠㝐├矄桌 Ӹ �㡰 �    矄�ᨨ  �     矄� � 盐� � 鼀ᨨ�ᨨ  ��㡰 꾀ᆠ� � 矄 ᨨ �鼀  鼀� �盐  ᨨ     �盐  ᨨᆠ�泐 ᨨ  Y �矄 ҈   s ҈  ᆠᆠ盐  �矄 ᆠ 泐X ᨨ鼀 � 矄 ᨨ �鼀盐 � �ᆠᨨ鼀矄ᨨ矄 黨 꾀 ᨨ鼀ᨨ� ᨨ盐矄ᨨ ABᨨ  � L㦨҈鼀 鼀矄矄M�矄 �ᨨ  ᆠ 졠� 矄盐ᆠ 犨泐 �ᆠ ᨨ 泐�  �ᆠ  ��㡰 ᨨ �矄� ��泐�   ᨨ� ᨨ ᨨ矄��ᨨ 꾀 � 矄ᆠSᨨ  矄鼀鼀矄矄M 矄 �ᆠ泐犨� 矄 Vᨨ  ᨨ� C鼀� 犨泐犨

 ᨨ� 矄O Bᔼ鼀鼀 �泐  � � � 矄ᆠ 鼀ᨨ矄ᨨ犨 矄  B矄盐ᆠ   ᨨ ᨨ矄犨�  ᆠᨨ 矄  �盐ᨨᆠ�泐w ᲼҈黨黨㜠㝐├矄桌 㡰 鼀�   �盐ᨨᆠ�泐 w � 鼀矄ᨨ V L 㡰 ᔼ    � 矄ᆠ ᆠ 矄     B 犨    ᨨ  矄 盐   ᨨ盐�   �ᨨ 黨  鼀� V

WWW.JEEBOOKS.IN

P-71

System of Particles and Rotational Motion

�矄 �� 矄ᨨᆠ� ᨨ矄 矄 ᆠᨨ � 盐ᨨᨨ ᨨ盐�矄ᆠ ᨨ 鼀矄矄䁸쟼 �  ᲼҈黨䰘㜠䰘㝐├矄桌

和 V



҈

O

L 

C

L 

L 

꾀 � 盐 � ᨨ鼀�矄ᨨ  �ᆠ�ᨨ 矄矄 ᨨ� ᨨ 矄盐 ᆠ �矄 ᨨ鼀ᨨ�

 泐犨泐ᨨ  矄盐 ᆠᔼ矄鼀矄矄�矄҈

B

鼀

A

҈鼀⏌矄



├�  �   鼀矄 犨ᨨ�ᆠ矄  鼀⏌矄 ᆠ ᨨ 鼀矄矄├�鼀ᨨ� �ᨨ   矄鼀 矄盐 ᆠ   ᨨ犨 矄    �   �ᆠ�ᨨ

 �ᆠ盐ᨨ ᨨ 犨� ᨨᆠ�泐ᨨ ҈鼀⏌矄 ᨨ 犨� 鼀⏌矄矄矄 ᨨ犨 �  ��  �矄�ᆠ矄�├矄  ᨨ� A  ᨨ ᨨ� Bᨨ� 矄A B  �矄 ᆠᨨ �鼀 ᨨ鼀 ᆠ ᨨ    �ᆠ矄矄�├  矄鼀� 矄 ᨨ �鼀 矄�ᆠ├ ᨨ ᨨ ᆠᨨ�矄�ᨨ ᔴᆠ盐 ᨨ矄矄ᨨ  ├� �ᆠ  �泐ᨨ  矄泐矄鼀�  ᨨᆠᨨ�矄�ᨨ ᨨᆠ矄矄 ᲼҈黨黨㜠㝐├矄桌 꾀矄鼀矄 ᨨ矄 ᨨ犨 犨� ᨨ盐矄�� � ᨨ鼀 ᨨᨨ ᆠ├� �ᆠ  ᆠ├ 矄  矄ᆠ�ᨨ

  ᨨ� ᨨ   ᨨ� ᨨ �矄҈鼀ᨨ  �ᨨ盐    ᨨᨨ  ᆠ├�矄鼀矄 ᨨ �ᨨ盐  �   �矄 ᆠᨨ  �ᨨ盐 犨� 矄ᆠᨨ ᨨ� B 犨 �ᆠ �矄�ᆠ泐ᨨ犨  ᨨ  ᆠ├矄矄 ᨨ犨 �  ��㡰犨  矄  矄盐� �

҈ 鼀 

 꾀�鼀矄矄M 矄鼀鼀矄矄m  �犨ᨨ 矄ᨨ 矄� �  矄矄矄 ᨨ  矄鼀ᨨᨨ  盐 矄 l 矄 ᨨ犨 �   ��盐 鼀矄矄鼀 鼀ᨨ矄ᨨ盐 ᆠ�ᆠ盐 犨 �ᆠ �矄�  ᨨ� ᨨ   鼀

 � ᨨ 矄� � ᨨ鼀 鼀矄矄 mᨨ ᨨᨨ  盐�矄l  q�矄  � � �矄 � 鼀├矄犨� 㝐   �ᆠ ␔  矄 ᨨ盐     ⼄盐 ᆠ泐 ᨨ  ᨨ�ᨨ  ᨨ  鼀矄矄 m 矄ᨨ    鼀矄矄 M 鼀� 矄矄�ᨨ 泐䁸 ᲼҈黨䰘桌  꾀├�鼀矄矄  �� �  ᨨ ᨨᨨ  � l ᨨ矄ᆠ�矄� �ᆠ 犨�   �盐鼀�盐 q0 ␔ �矄  矄�ᨨ �  ᨨ犨  �鼀├矄  �q 犨�  �ᆠ䁸ᔼ  ├� �矄 � ᨨ  ᨨ�矄 ├�犨 �矄 鼀 �鼀盐鼀鼀�盐 犨� 犨 �ᆠ  鼀矄矄 ᆠ ᨨ矄ᆠ�犨� ᨨ盐 ᨨ├� �䁸 ᲼҈黨䰘桌

WWW.JEEBOOKS.IN

EBD_8341 P-72

Physics

Answer Key Topic-1 : Centre of Mass, Centre of Gravity & Principle of Moments ҈

㡰

 㡰

 㡰

 㡰

� 㡰

 㡰

䰘 ᆠ㡰

҈҈



҈ 㡰

҈ ᆠ㡰

҈ 㡰

҈� 㡰

҈ 㡰

҈䰘 㡰



矄 ҈ ᆠ㡰

 ᆠ㡰

 㡰

 ᆠ㡰

黨 㡰

҈ ᆠ㡰

æ d - x ö xw ҈ 㡰҈黨 ç ÷ w d è d ø

Topic-2 : Angular Displacement, Velocity and Aceleration ҈ ҈҈

㡰 㡰

 ᆠ㡰 ҈ 㡰

 ᆠ㡰 ҈ 㡰

 㡰

� 㡰

 ᆠ㡰

䰘 ᆠ㡰

 㡰

黨 㡰

҈ ᆠ㡰

Topic-3 : Torque, Couple and Angular Momentum ҈ ҈҈ ҈ ҈

ᆠ㡰 㡰 ᆠ㡰 㡰



�ᆠ鼀㡰

҈ 㡰

 ��

ᆠ㡰 䰘 ᆠ㡰 ᆠ㡰 �  㡰

 ᆠ㡰

 ҈  

㡰 㡰 㡰 ᆠ㡰

 ҈  

㡰 㡰 㡰 㡰

㡰 � 㡰 ҈� ᆠ㡰 � ᆠ㡰 � ҈  㝐꾀 w  黨 ᆠ 㡰  ҈  

ᆠ㡰 㡰 㡰 㡰

㡰 䰘 㡰 ҈䰘 㡰 䰘 㡰 䰘 Mw  M + m � 㡰 �҈

 ҈  

㡰 㡰 㡰 㡰

 ҈  

㡰 㡰 㡰 㡰

黨 ҈黨 黨 黨

㡰 ҈ ᆠ㡰 㡰  ᆠ㡰 㡰  㡰 黨㡰

 矄 � ᆠ 㡰 ᆠ㡰

� 㡰

� ᆠ 㡰 � 㡰

Topic-4 : Moment of Inertia and Rotational K.E. ҈ ҈҈ ҈ ҈ ҈

㡰 ᆠ㡰 㡰 㡰 㡰

 ҈   

㡰 㡰 㡰 㡰 黨㡰

 ҈   

㡰 ᆠ㡰 㡰 㡰 ҈҈㡰

 ҈   

ᆠ㡰 㡰 㡰 ᆠ㡰 㡰

� ҈� � � �

㡰 㡰 ᆠ㡰 㡰 �㡰

 ҈   

ᆠ㡰 㡰 㡰 㡰 ҈�㡰

䰘 ҈䰘 䰘 䰘 䰘

㡰  㡰 ҈ 㡰  㡰  㝐㡰

㡰 黨 ᆠ㡰 ҈黨 㡰 黨 㡰 黨  ᆠ㡰

㡰 ᆠ㡰 ᆠ㡰 㡰

҈   

㡰 㡰 ᆠ㡰 㡰

Topic-5 : Rolling Motion ҈ ҈ ҈黨

㡰 㡰 ᆠ㡰

 㡰 ҈҈ 㡰  㡰

 ᆠ㡰 ҈ 㡰 ҈ ᆠ㡰

 ᨨ 盐矄㡰 � ҈ ᆠ㡰 ҈ 䰘㡰  ᆠ 㡰  㡰

㡰  ҈� 㡰

ᆠ㡰 䰘 ҈ �㡰

ᆠ㡰  㡰 黨 ᆠ㡰 ҈䰘 䰘�㡰 ҈ 矄

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈ ҈҈

㡰

 㡰

 㡰

 㡰

矄 ҈ ᆠ㡰 ҈ 㡰

҈ ᆠ㡰

҈䰘 꾀錐  ® ⼄矄 㡰 錐 ᔴ ®   㡰   ® ⼄ 㡰  ᆠ㡰 � 㡰  㡰 䰘 ᆠ㡰

� ᆠ㡰

 ᆠ㡰

䰘 ᆠ㡰

 㡰

 㡰

҈ 㡰

黨 㡰

҈

 鼀� 

҈� ᆠ 㡰 ҈ 㡰 ҈ ᆠ㡰

҈黨 㡰

 㡰  㡰

WWW.JEEBOOKS.IN

P-73

Gravitation

Gravitation

7

Topic-1 : Kepler's Laws of Planetary Motion 1 ҈

㡰 � TA>TB  MA>MB

ᔼ   �盐鼀ᨨ鼀 盐鼀ᨨ  ᨨ 鼀矄矄鼀鼀ᨨ� � ᨨ盐  和盐 � ᆠ�ᆠ盐ᨨ��矄ᨨ盐 ᆠ ᨨ  和盐 �矄ᨨᆠ�泐�矄 ᲼㝐� 黨 ҈黨ᔼ桌 㡰

ᆠ㡰 

㡰 � TA>TB  RA>RB

MCQs with One Correct Answer

 鼀

㡰

 鼀



 鼀



ᆠ㡰



 鼀

��盐矄 ᨨ犨矄��ᆠ ᆠ ᨨ  ᨨ盐   ҈  ᨨ    �矄 和 ��盐㡰␔�  矄 矄鼀�鼀ᨨ �矄 ᆠ 矄 矄鼀�鼀� ᨨ �矄ᔼ ҈�矄 �鼀├  ᨨ ᨨ�ᨨ ᨨ ᆠ  ᨨ ├ ᨨᆠ    ᲼㝐� 졠 � 꾀�黨҈桌

�



 和



҈㦨 ҈㦨

MCQs with One or More than One Correct Answer

ᔼ鼀�� ��  ᨨ� �ᨨ盐 泐鼀矄矄� 矄� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄R犨� �ᨨ ᨨ ᨨ盐�ᨨ

Tᔼ  ���ᨨ  ᨨᆠᨨ ᆠ�ᨨ 犨      矄�矄ᨨᨨ�ᨨ ᨨR�⏌᲼҈黨黨㜠㝐├桌 㡰 T�矄ᨨᨨ�ᨨ ᨨR 㡰 T�矄ᨨᨨ�ᨨ ᨨR䰘⏌ ᆠ㡰 T�矄ᨨᨨ�ᨨ ᨨR⏌ 㡰 T�矄ᨨᨨ�ᨨ ᨨR⏌䰘 10 Subjective Problems

 㡰 ᆠ㡰



㡰 TA㦨TB ᔼ   �矄 ᆠ犨     矄盐 犨  �矄 矄 盐  盐鼀ᨨ  泐矄� 泐犨ᨨ盐   

᲼҈黨黨㜠㝐├矄桌 㡰 � 㡰 ҈黨 ᆠ㡰 ҈� 㡰 䰘 6

矄盐 和矄盐ᆠ   ᨨ � �ᆠ矄�矄

æ TA ö æ RA ö çè T ÷ø = çè R ÷ø B B

 㡰 ҈㦨 㡰 ҈㦨

꾀� 泐矄矄泐矄鼀ᆠᨨ 矄�矄矄ᨨ 犨ᨨ矄矄A B犨 �ᆠ �鼀�ᨨ TA TB �盐矄RA  RB 鼀矄矄 MA MB 

᲼㜠㝐҈桌

犨ᨨ矄�矄S҈ Sᨨᨨ盐  � ᆠᨨ  ᆠ�ᆠ盐ᨨ�矄�  矄鼀矄 矄 ��ᨨ 矄ᨨ ᨨ盐�ᨨ

҈ ᨨ盐  ᨨ盐矄矄ᆠ�泐  �盐矄ᨨ  ᨨ� ᨨ S҈�矄҈├鼀␔  S�矄ᆠᨨ矄矄ᨨS҈ � �㡰  矄 ᨨ S�ᨨS҈ ��㡰   �盐矄 ᨨ S矄ᆠ盐泐ᨨ矄 泐

矄ᨨ 盐� S҈ ᲼҈黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-74

Physics

Topic-2 : Newton's Universal Law of Gravitation 1 ҈

MCQs with One Correct Answer



꾀矄�� ᨨ ᨨ  �   矄 ᨨ鼀x 㦨 aᨨx 㦨졔

���ᨨ  ᨨᆠ� 矄ᨨ ᨨ� 鼀矄矄�鼀x 㦨 �  鼀矄矄盐 � � ᨨ  ᨨ �矄꾀졔x�矄��

᲼㝐� ҈ ҈黨ᔼ桌 泐 㡰

㡰

é æ ҈ ù ҈ö ෌鼀 ê 꾀 ç - ÷ -  ú a + L a ø ë è û

㡰

é æ҈ ù ҈ ö ෌鼀 ê 꾀 ç ÷ -  ú a a + L ø ë è û

ᆠ㡰

é æ ҈ ù ҈ö - ÷ +  ú ෌鼀 ê 꾀 ç a + L a è ø ë û

෌㝐



é æ҈ ù ҈ ö ෌鼀 ê 꾀 ç ÷ +  ú ë èa a+Lø û

├ 鼀  �矄 ᆠᨨ  鼀ᨨᨨ   矄盐  ᨨ鼀   ᨨ맔҈├鼀 ҈�맔҈├鼀矄ᆠ�泐

�鼀矄矄矄맔҈├� 맔҈├�矄ᆠ�泐

 �盐矄ᨨ   �矄├鼀D ҈  �  ᆠ �   ᨨᆠ矄  泐 鼀ᨨᨨ   矄   矄 ᨨ� 矄ᨨ    D   �  ᆠ�   ᨨᆠ   泐 矄盐   矄   矄ᨨ� 矄ᨨ

DF҈ �矄 DF ᲼㝐� 졠 � 꾀�҈�҈桌 ᆠ㡰 ҈ 㡰 

(

㡰 

෌㝐

)

(

)



      盐鼀ᆠᨨ矄矄ᨨ 㡰 

 

㡰

෌㝐 ҈ ෌㝐 ҈+   ҈+   㡰  ᨨ鼀矄 ᨨ 鼀矄矄㝐  �盐矄 矄鼀矄 ᨨ  �盐矄 �矄ᆠ ᨨ盐矄盐ᆠ   ᆠ�泐鼀 �    ᨨ��� 矄 �矄犨  �矄 ᆠ    � 泐 和 ��盐㡰 ᨨ ᆠᨨ ��盐�ᨨ �   ��盐犨   �矄 ᆠ犨  ᆠ ᨨ  ᨨ��� 矄    鼀ᨨ 矄 �矄  ���ᨨ  ᨨᆠ犨   犨ᨨ矄 �矄 ᲼㝐� 졠 � 꾀�҈҈҈桌

ᆠ㡰





ᨨ盐�ᆠ矄ᆠ ᨨ 鼀矄矄㝐 ⼄盐� �矄  ᨨ鼀ᆠ ᨨ 鼀ᨨᨨ �ᆠ�ᆠᨨ  �盐矄 盐  ᆠ�ᨨ ᨨ  �鼀盐盐���ᨨ ᆠ�ᨨ  矄 ᨨ ᆠ �ᆠ�矄 ᲼㝐� ҈桌

㡰

҈ ෌㝐



 

㡰

�黨 ෌㝐 

҈ ෌㝐 

ᆠ㡰 � 

� 



෌㝐 

� 

Topic-3 : Acceleration due to Gravity 1 ҈

矄� � ᆠᔼ  犨�� 矄 ᨨ盐 ᨨ矄鼀  h �矄 hR犨 R�矄  �盐矄ᨨ   㡰 ᲼㝐� �和 ᔼᔼ㡰桌

MCQs with One Correct Answer

盐ᨨ ᆠᆠ�ᨨ  盐ᨨ��泐�矄g҈ ��  R  R㦨 �盐矄ᨨ   㡰 ᨨ鼀 矄盐 ᆠᨨ     ᔼ�矄�� ⼄盐ᨨg҈   dᨨ犨 矄盐㜠

h㦨

ædö ᆠᨨ    �ᨨ ç ÷ ⼄盐矄 è Rø ᲼㝐� �和 ᔼ㡰桌  � ҈ 䰘 㡰 ᆠ㡰 㡰 黨 黨  黨

ᆠᆠ�ᨨ  盐ᨨ��泐ᨨ   矄矄盐 ᆠ  ᨨ矄�矄g  �盐ᨨᆠ�泐ᨨ   ᨨ盐   �矄矄矄� � ᨨ盐�  ᨨ�矄w꾀 ᨨᆠ�矄犨��    ⼄盐ᨨ  �� hᨨ ᨨ矄泐盐矄� �

㡰



㡰



R w  g

㡰

R w  g

R w  R w  ᆠ㡰 㡰 g g

 �� ἘhἘ犨 �ᆠ  犨�� ᨨ ᨨ 泐犨�  矄鼀矄  矄鼀  ἘhἘ ᨨ鼀 矄盐 ᆠᨨ    �矄  �盐矄ᨨ   �矄R  ᆠᨨ  ᨨ�ᨨ

ᨨ   �矄 �ᆠ 㡰 [Main 2 Sep. 2020 (II)]

㡰

� R-R 

㡰

ᆠ㡰

�R - R 



R 

R - R 

WWW.JEEBOOKS.IN

P-75

Gravitation



�

꾀ᨨ 犨�� 矄҈黨ᨨ 矄� � ᆠ  ᨨ ᨨ ᔼ矄犨�� ᆠᨨ  ᨨ  矄鼀 ᆠ� ��矄矄 �  ᨨ  ⼄盐ᨨ�矄ᆠᨨ矄ᨨ ├g㦨҈鼀矄  ᨨ ᨨ    �盐矄ᨨ   㦨├鼀㡰 ᲼㝐� 䰘 ᔼᔼ桌 㡰 ҈黨� 㡰 ҈黨 ᆠ㡰 ҈黨 㡰 ҈黨�

�ᨨᨨ  犨�� 矄ᨨ ᨨ 泐ᨨ  쟼 矄矄盐 ᆠᨨ   ᨨ   矄盐 ᆠᨨ     �矄 黨 鼀矄矄 ᨨ   ҈  �矄  ᨨ  ᨨ  쟼 ᔼ � �矄  �盐矄ᨨ   黨 쟼 犨 �矄  �盐矄ᨨ   䁸 ├  矄 ᨨ  矄鼀鼀矄矄  矄�泐㡰᲼㝐� ҈꾀�҈黨ᔼᔼ桌 R R R R 㡰 ᆠ㡰 㡰   黨 

盐ᨨ ᆠᆠ�ᨨ  盐ᨨ��泐쟼 矄矄盐 ᆠ �矄黨鼀矄 �盐 ᨨ�矄矄盐 ᆠ犨 �ᆠ   ᆠᆠ�ᨨ  盐ᨨ��泐 ᆠ矄矄ᨨ黨鼀矄�矄ᆠᨨ矄 ᨨ  �盐矄ᨨ  㦨맔҈鼀㡰᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 맔҈鼀 㡰 맔҈鼀  ᆠ㡰 黨맔҈ 鼀 㡰 ҈맔҈鼀 和盐ᨨ矄   �盐ᨨᆠ�泐ᨨ ᨨ�ᨨ  ᨨ  �矄 � ᆠ矄   矄ᆠᨨ 矄⼄盐 ᆠ ᲼㝐� 졠 � 꾀�҈҈桌 㡰 犨� ᨨᆠ  �� 犨��  泐犨 ᨨ   㡰 ␔�� ᨨ  ᨨᆠ泐犨 ᨨ   犨� ᆠ矄 ᆠ㡰 ␔�� ᨨ  ᨨᆠ泐犨 ᨨ   犨�� ᆠ矄 㡰 쟼 ᆠᨨ矄犨�� ᨨ  ᨨᆠᨨ   犨� ᆠ矄

��ᨨ ᨨ ᆠᆠ�ᨨ  盐ᨨ��泐�犨�  �矄 ᆠ  ᨨ鼀 ᆠ  ᨨ      �矄 矄 矄   泐 㦨쟼 Ἐ矄 �盐矄㡰 ᲼㝐� ҈䰘桌 � �

黨

ᔼ  쟼  矄 ᨨᨨ�ᨨ 鼀ᨨ�ᨨ  犨�� ᨨ 矄ᨨ

ᨨ  ⼄盐ᨨ�矄␔鼀�  矄 犨� 犨 �ᆠ    犨ᨨ盐  ᨨᨨᨨ盐�矄 �矄矄ᨨ  矄ᨨ

├鼀 �㦨҈鼀⏌矄

 ␔   �盐矄ᨨ  쟼 �矄  ᲼㝐� 졠 � 꾀�҈䰘桌

㡰 ҈҈맔҈ ⏌矄

㡰 맔҈ ⏌矄

ᆠ㡰 맔҈ ⏌矄

㡰 맔҈ ⏌矄

 ⼄盐ᨨ犨�犨�� 

҈ ´ (  �盐矄 ᨨ 쟼 ) 矄   ҈ 矄鼀鼀矄矄  矄�泐矄쟼 和ᆠ� �矄矄 ��犨ᨨ  

҈ 꾀   ᨨ   �盐矄 R =

㡰



䰘



㡰



㡰







� ᆠ㡰







鼀矄矄ᨨ  鼀ᨨᨨ 㦨䰘맔҈├� �盐矄ᨨ  鼀ᨨᨨ 矄 ᨨ�㦨맔҈鼀㡰 ᲼㝐� 졠 � 꾀�҈桌 㡰 䰘맔҈�鼀⏌矄



㡰 䰘맔҈鼀⏌矄

ᆠ㡰 䰘맔҈鼀⏌矄 㡰 䰘맔҈鼀⏌矄 ҈ ᔼ   �盐矄ᨨ   犨ᨨ矄 � ├泐ᨨ ᆠ �矄 鼀矄矄鼀� � � 矄鼀 ᆠᆠ�ᨨ  盐ᨨ��泐 ᨨ   矄矄盐 ᆠ犨ᨨ盐 ᲼҈黨҈㜠㝐├矄桌 㡰 ᆠ矄 㡰 鼀� 盐 ᆠ  � ᆠ㡰 � ᆠ矄 㡰  ᨨ 4

㡰



R ᨨ � ᨨ犨犨�ᨨ  矄鼀 �  �  � 鼀矄矄  矄�泐҈├�鼀҈� ᨨ�ᔼ  犨��矄 ᨨᨨ盐ᆠ � �  泐犨   ᨨᆠ�  ᨨᨨ  犨�泐矄ᨨ

ᨨ � ��� ᆠ�矄 ├  �盐矄ᨨ 쟼 㦨맔҈鼀  ᆠᆠ�ᨨ  盐ᨨ��泐ᨨ 쟼 �矄҈鼀矄㡰 ᲼꾀 ҈桌 㡰 黨 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈� ҈҈ ᆠ  ��  盐ᨨ ᆠᆠ�ᨨ ᨨ  ᨨ犨 矄 矄盐  犨     鼀ᨨᨨ  ᆠᨨ鼀矄 ᨨ鼀   ᨨ矄��ᨨ  ᨨ  矄ᨨ ᆠ�矄ᨨ ᨨ矄��ᨨ ᨨ  ᨨ 矄� ᨨ  � �  犨� 矄盐 �矄

Fill in the Blanks

҈  盐鼀�ᆠ盐ᨨ   �盐ᨨᆠ�泐ᨨ ᨨ�ᨨ ᨨ     矄 ᨨ盐   ⏌矄�  ᨨ  ᨨ鼀├   ᆠ�ᆠᆠ�ᨨ  盐ᨨ��泐⼄盐ᨨ ᨨ ᲼҈黨㜠㝐├矄桌

Topic-4 : Gravitational Field, Potential and Potential Energy 1 ҈

MCQs with One Correct Answer

犨ᨨ 矄 鼀矄矄矄M ҈M  � ��a  a矄ᆠ�泐 矄�ᨨ 犨  ᆠ 矄 ᨨ   矄�矄҈a꾀ᨨ 泐ᨨ 鼀矄矄鼀�矄 �  ᨨ鼀  矄盐 ᆠᨨ  � ᨨ犨 矄 矄鼀 ᨨ �  � ᨨ� � � �ᆠ 矄 ᨨ ᨨ 泐ᨨᨨ

ᆠ  矄盐 ᆠᨨ 矄鼀  鼀� �鼀盐鼀 �� � 矄    �矄 ᲼㝐� 和 ᔼᔼ㡰桌 㡰  ᆠ㡰

GM a

GM  ma

㡰  㡰

GM a

 �GM a 

WWW.JEEBOOKS.IN

EBD_8341 P-76



Physics

졠   x㜠 �矄   �矄 ᆠx ᨨ鼀  ᨨ���    ���ᨨ  �  盐ᨨ鼀矄矄 �矄�盐�ᨨ �矄�� 泐 Ax

x + a  㡰⏌ 

A

x + a 㡰

҈

x + a 㡰









ᆠ㡰 A x  + a  㡰  㡰 A x + a 㡰

鼀矄矄  矄�泐ᨨ  ᨨ  �盐矄R�矄犨�   





㡰 r =  R 㡰 r = R  ҈ � R 㡰 r = ᆠ㡰 r = R  黨 ᔴᨨ 矄� 犨ᨨ矄ᨨ� 矄 矄ᨨ  ��R҈㦨҈mR㦨m 鼀矄矄矄M҈ M矄ᆠ�泐 ���ᨨ  � m҈ 盐ᨨ矄  ҈    矄 ᨨ犨  盐ᨨ  m �矄  ᲼㝐�  ᔼ桌



෌��ᨨ  � E

෌㝐 a

㡰 ҈҈

෌㝐 a

꾀矄�ᆠ�矄鼀ᨨ� �� ᆠ�ᆠ盐ᨨ��  ���ᨨ 

ᆠ㡰 ⏌ �矄ᆠᨨ 矄  㡰 �矄ᆠᨨ 矄  꾀ᨨ 泐ᨨ 鼀矄矄鼀�矄鼀ᨨ� �� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄R ᨨ盐 ᨨ 鼀矄矄M꾀矄ᨨ鼀� 矄 �矄�矄� ᨨ 犨ᨨ⼄盐鼀矄矄矄  �矄鼀矄矄鼀ᨨ矄� ᆠ�ᆠ盐ᨨ� R   ᨨ 鼀矄矄� ᆠ�ᆠ盐ᨨ�ᨨ 

R   �  ᆠ犨   �  � ��  ᨨ ��矄�矄 ᲼㝐� 졠 � 꾀�҈�҈桌  �盐矄

GMm GMm GMm GMm 㡰 + ᆠ㡰 㡰  R  R R R ᨨ鼀矄ᨨ� 矄 ᨨ 鼀矄矄㝐  �盐矄 矄 �ᆠ ᨨ�ᨨ ᨨ  �盐矄 ⏌�矄鼀ᨨ 矄矄 ᨨ犨 �   ��盐

├� ����ᨨ ᨨ �㦨㦨¥ ᨨ �  ᆠ ᨨ  ᆠ�泐 盐矄 ᨨ鼀 �矄 G = grav�tat�ᨨnal cᨨnstant㡰 ᲼㝐� ҈�桌

㡰

黨





-

҈

҈

҈







�  �盐矄 R

 ҈ ҈ ҈ 㡰 ᆠ㡰 㡰     꾀矄ᨨ� 矄 ᨨ 鼀矄矄�㝐  �盐矄��矄矄盐ᨨ盐  泐 盐 � ᨨ鼀ᆠᨨ ᆠ �ᆠ矄 �ᆠ矄 ᨨ  �ᆠ├ 矄矄 鼀矄矄㝐 ���ᨨ  �  �矄 ᆠ� ᨨ鼀  ᆠ 犨� ᲼㝐� 黨꾀�҈黨ᔼ桌 ෌㝐 

㡰

෌㝐 

ᆠ㡰

෌㝐 

㡰

-෌㝐 -෌㝐 -෌㝐 -෌㝐 㡰 ᆠ㡰  㡰   ␔ �ᆠ ᨨ   ᨨᨨ犨� �鼀ᨨ矄ᆠᨨ矄泐 �ᆠ矄 ᆠᨨᆠ ��ᨨ ᨨ  ���ᨨ ᨨ � 㡰 盐ᨨ�  ᨨ  �盐矄  盐 � ᨨ鼀鼀矄矄  矄�泐䁸 ��盐矄  ᨨ 犨  ᨨ 矄ᆠ㡰᲼㝐�  졠 �  꾀� ҈҈ ҈�桌

㡰

㡰



ᆠ㡰 ҈҈

ᨨ  �盐矄





㡰

෌㝐 a

K ᔼ  � 泐  r ᆠᨨᆠ�ᨨ 犨   �盐矄 ᨨ  �ᆠ矄ᨨ�  �矄�ᨨ   ᲼㝐� 꾀�҈黨ᔼᔼ桌  㡰 ⏌ �矄ᆠᨨ 矄  㡰 ⏌ �矄ᆠᨨ 矄 



�

㡰 ҈҈

� ᨨ 盐ᆠ 泐鼀矄矄  矄�泐 r r 㡰 =

æ r ö �矄 ᆠr ᨨ鼀�矄ᆠ 矄 r r 㡰 = r çç҈ -  ÷÷      è R ø ���ᨨ  � �矄鼀 �鼀盐鼀᲼㝐� 和 ᔼᔼ㡰桌



䰘

A

㡰 ҈



෌㝐 a

 �    x㜠 �ᆠ�ᨨ   鼀� �盐  ᨨ

���ᨨ ᨨ �ᨨ  x㜠 �矄 �矄 ᆠx├� � �矄盐ᨨ ᨨ� � �泐�矄 [Main 4 Sep. 2020 (I)] 㡰

㡰 ҈�

҈

෌㝐

黨a a 黨a a  ᨨ盐�  �ᆠ�ᆠ矄ᨨ 鼀矄矄㝐ᨨᆠ  ᆠᨨ 矄 ᨨ 矄⼄盐ᨨ 矄� �a␔ 矄 ᨨ盐  �矄 � ᆠ ᨨ   鼀 ᨨ矄 盐    � 盐 ᆠ ᨨ  ᨨ 矄 ���ᨨ  � � ᆠ�ᆠ盐ᨨ�ᆠ�ᆠ盐鼀矄ᆠ�� �  矄⼄盐䁸 ᲼㝐� 꾀�҈黨ᔼ桌

 㡰  㡰

㡰

 㡰 ᆠ㡰

㡰















 㡰





WWW.JEEBOOKS.IN

P-77

Gravitation





҈҈  ���ᨨ  �  �   ��ᨨ  �矄 ��  泐 ®

� = � ⏌ ├��ˆ + ҈ ⏌ ├�ˆ  ᆠ  ��  ���ᨨ  ᨨ � �泐ᨨ �ᆠᨨ 鼀矄矄҈├�犨  ��矄├

ᨨ鼀 ᨨ��� ᨨᨨ�  䰘鼀鼀㡰�矄 ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰 䰘҈ 㡰 ҈ � ᆠ㡰 䰘҈ 㡰 ҈ 鼀 鼀 ҈ ҈ ҈ 

犨ᨨ 泐ᨨ �ᆠ 矄ᨨ 鼀矄矄矄鼀҈ 鼀矄 犨    泐 � � � �矄 ᆠ  ᆠ盐矄ᨨ    ���ᨨ  ᨨᆠ 泐鼀ᨨᨨ犨 矄ᆠ ᨨ ᨨ �  � ᨨ� � � �ᆠ 矄␔ �矄 �矄 犨 

 �矄�ᨨ �矄� 䁸᲼㝐� 졠 � 꾀�҈҈桌 和 ᨨ 鼀҈�矄҈  ᨨ 鼀�矄㡰 㡰 ҈㦨 ҈ = 鼀 

෌ ෌   = 鼀҈ ( 鼀҈ + 鼀  ) ( 鼀҈ + 鼀  )

ᆠ㡰

҈ = 鼀҈

෌ ෌   = 鼀 ( 鼀҈ + 鼀  ) ( 鼀҈ + 鼀  )



҈ = 鼀 

෌ ෌  = 鼀   鼀҈ 鼀

㡰

㝐矄矄ᨨ ᆠᨨ鼀 矄 㦨㝐

MCQs with One or More than One Correct Answer

҈䰘 鼀� �盐 矄ᨨ  ���ᨨ  �  �矄 ᆠr҈  r ᨨ鼀 ᆠ ᨨ 盐 � ᨨ鼀矄 ᨨ  �盐矄R 鼀矄矄mF҈ F矄ᆠ�泐  ᲼҈黨黨㜠㝐├矄桌 F҈ r҈ 㡰 F = r �  r҈ < R  r < R   㡰

F҈ r = F r҈ �  r҈ > R  r > R

ᆠ㡰

F҈ r҈ = F r �  r҈ > R  r > R

F҈ r҈ = F r �  r҈ < R  r < R ҈ 꾀矄ᨨ� 矄 ᨨ 盐 � ᨨ鼀  矄�泐  �盐矄盐 �矄�矄 ᨨᆠ 犨� �矄ᆠ  ᨨ��� Oᨨ ᆠᨨᨨ � 矄 犨ᨨ 矄 矄ᨨ ⼄盐 ��҈盐 �犨�  �ᆠ 矄A  㡰  㡰矄ᆠ�泐├ ᨨ盐ᨨ  矄ᨨ� � � � 矄 �ᆠᆠ��矄矄矄 ᨨ犨 �  �� y

  ᲼҈黨黨㜠㝐├矄桌 㡰





㡰

  ҈� ᔼ g�矄 ᆠᆠ�ᨨ  盐ᨨ��泐ᨨ   矄矄盐 ᆠ  �� �  ᨨ � �泐ᨨ  ᨨᆠᨨ 鼀矄矄m �矄  ᨨ鼀 矄盐 ᆠᨨ   ᨨ �� ⼄盐ᨨ   �盐矄 ᨨ   �矄 ᲼҈黨㜠҈㝐├桌 ҈ ҈ 㡰 mg R 㡰 mg R ᆠ㡰 mg R 㡰 mg R   3 Numeric Answer ҈ 꾀 矄ᨨ� �矄鼀ᨨ� � �ᆠ泐ᨨ犨 矄 ᆠ ᨨ    ␔   �矄 ᆠᨨ ҈R R�矄  �盐矄ᨨ    㡰 ᨨ鼀  矄ᆠ � 矄矄 ᨨ ҈├鼀⏌矄 �ᆠ� �  ᆠᨨ  矄鼀ᨨ矄 犨 犨�  矄 ᨨ  矄ᨨ� 犨   � �矄 矄盐 ᆠᨨ     矄ᆠᨨᆠ�泐 ᨨ鼀  �矄҈҈├鼀⏌矄㡰䁸෌� 泐ᨨ盐 矄犨ᨨ  矄� �� ├�ᨨ鼀⏌矄힘힘힘힘힘 ᲼㝐�  ᔼᔼ桌

6

҈ ���ᨨ  �  盐ᨨ Ἐ ᨨἘᨨ 盐 � ᨨ鼀 矄  ᨨ鼀犨 �ᆠ 矄矄 ᨨ犨  矄 Ἐ鼀ᨨ ᨨ盐Ἐ㡰泐 ᨨ ᨨ� ᨨᆠ 矄矄 ᨨ犨 犨ᨨ盐  泐㡰 ᲼㝐� 졠 � 꾀�黨҈桌 鼀ᨨ 

ᆠ㡰

x

䰘 GM  GM  GM � GM 㡰 ᆠ㡰 㡰  x 䰘 x 黨 x  x ҈ 꾀矄 �ᆠ泐矄泐鼀鼀�ᆠ���ᨨ 矄泐矄鼀ᨨ �ᆠ矄 㡰

ìr ᨨ  £ î ᨨ  >

矄鼀矄矄  矄�泐 r = í

犨 r�矄ᆠᨨ 矄 꾀矄鼀矄矄ᆠ 盐 �ᨨᆠ�ᆠ盐 鼀ᨨ�ᨨ 盐  � 盐 ᆠᨨ  ���ᨨ  � ᨨ �ᆠ矄ᔼ矄矄 矄 盐 ᆠ�ᨨ ᨨ  �矄 ᆠ ¥㡰 ᨨ鼀 ᆠ ᨨ  矄泐矄鼀�矄矄  泐  ᲼桌 

㡰

㡰







A

㜠m

O

B

x

z

㡰 ���ᨨ  ᨨᆠ 盐ᨨ �矄ᨨᆠ ᨨ��� �矄 ᨨ 㡰  ���ᨨ  ᨨᆠ ᨨ�  㡰�矄 ᨨ ᆠ㡰  ���ᨨ ᨨ ��矄 矄鼀ᨨ� 矄ᨨ ᆠ�ᆠy졔z㦨 㡰  ���ᨨ ᨨ ��矄 矄鼀ᨨ� 矄ᨨ

 ᆠ�ᆠy졔z㦨



WWW.JEEBOOKS.IN

EBD_8341 P-78

Physics

Topic-5 : Motion of Satellites, Escape Speed and Orbital Velocity 1.

2.

3.

A satellite is in an elliptical orbit around a planet P. It is observed that the velocity of the satellite when it is farthest from the planet is 6 times less than that when it is closest to the planet. The ratio of distances between the satellite and the planet at closest and farthest points is : [Main 6 Sep. 2020 (I)] (a) 1 : 6 (b) 1 : 3 (c) 1 : 2 (d) 3 : 4 A body is moving in a low circular orbit about a planet of mass M and radius R. The radius of the orbit can be taken to be R itself. Then the ratio of the speed of this body in the orbit to the escape velocity from the planet is : [Main 4 Sep. 2020 (II)] 1 (a) (b) 2 2 (c) 1 (d) 2 A satellite is moving in a low nearly circular orbit around the earth. Its radius is roughly equal to that of the earth’s radius Re. By firing rockets attached to it, its speed is instantaneously increased in the direction of its motion so

7.

vA n = . vB 4 The value of n is :

(a) 4 8.

(a) 5.

T 2 µ R (b) T 2 µ R3 (c)

T2 µ

R3

(d) T µ R

A body A of mass m is moving in a circular orbit of radius R about a planet. Another body B of mass

6.

1

m collides with 2

r æ vö A with a velocity which is half çè ÷ø the instantaneous 2 r velocity v or A. The collision is completely inelastic. Then, the combined body: [Main 9 Jan. 2020 I] (a) continues to move in a circular orbit (b) Escapes from the Planet’s Gravitational field (c) Falls vertically downwards towards the planet (d) starts moving in an elliptical orbit around the planet The energy required to take a satellite to a height 'h' above Earth surface (radius of Eareth = 6.4 × 10 3 km) is E1 and kinetic energy required for the satellite to be in

(c) 2

(d) 3

A satellite of mass m is launched vertically upwards with an initial speed u from the surface of the earth. After it reaches height R (R = radius of the earth), it m so that subsequently the 10 satellite moves in a circular orbit. The kinetic energy of the rocket is (G is the gravitational constant; M is the mass of the earth): [Main 7 Jan. 2020 I]

3 times larger. Due to this the farthest 2 distance from the centre of the earth that the satellite reaches is R. Value of R is : [Main 3 Sep. 2020 (I)] (a) 4Re (b) 2.5Re (c) 3Re (d) 2Re

4.

(b) 1

[Main 9 Jan. 2020 II]

ejects a rocket of mass

that it become

K The mass density of a spherical galaxy varies as over r a large distance 'r' from its centre. In that region, a small star is in a circular orbit of radius R. Then the period of revolution, T depends on R as : [Main 2 Sep. 2020 (I)]

a circular orbit at this height is E2. The value of h for which E1 and E2 are equal, is: [Main 9 Jan. 2019 II] (a) 1.6 × 103 km (b) 3.2 × 103 km (c) 6.4 × 103 km (d) 28 × 104 km Planet A has mass M and radius R. Planet B has half the mass and half the radius of Planet A. If the escape velocities from the Planets A and B are vA and vB, respectively, then

(a)

m æ 2 113 GM ö çu + ÷ 20 è 200 R ø

3m æ 5GM ö u+ (c) ç 8 è 6 R ÷ø

9.

2

æ 2 119 GM ö (b) 5m çè u ÷ 200 R ø mæ 2GM ö u(d) 20 çè 3 R ÷ø

2

A spaceship orbits around a planet at a height of 20 km from its surface. Assuming that only gravitational field of the planet acts on the spaceship, what will be the number of complete revolutions made by the spaceship in 24 hours around the planet ? [Given : Mass of Planet = 8×10 22 kg, Radius of planet = 2×10 6 m, Gravitational constant G = 6.67×10–11Nm2/kg2] [Main 10 April 2019 II] (a) 9

(b) 17

(c) 13

(d) 11

10. A rocket has to be launched from earth in such a way that it never returns. If E is the minimum energy delivered by the rocket launcher, what should be the minimum energy that the launcher should have if the same rocket is to be launched from the surface of the moon? Assume that the density of the earth and the moon are equal and that the earth’s volume is 64 times the volume of the moon. [Main 8 April 2019 II] (a)

E 64

(b)

E 32

(c)

E 4

(d)

E 16

WWW.JEEBOOKS.IN

P-79

Gravitation

҈҈ 꾀矄�ᨨ 鼀矄矄㝐�矄� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄 ᨨ盐  ᆠ ᨨ   꾀鼀ᨨ�ᨨ  矄鼀鼀矄矄 � � ᨨ犨 矄  ᆠᨨ� 矄犨�  矄�ᆠᨨ鼀泐�

矄�ᆠ泐 矄 矄ᨨ  矄�  鼀ᨨ�  矄鼀盐矄 ᨨ ᆠᨨ�矄�ᨨ  矄盐矄⼄盐 鼀ᨨ�ᨨ

ᨨ  ᆠᨨ鼀�  ᨨ 泐犨�᲼㝐� ҈ ҈黨ᔼ桌 㡰 矄盐ᆠ  �矄ᆠᨨ� � �泐 㡰 ᔼ  ��ᆠᨨ� ᆠ㡰 �  矄鼀ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄 㡰 � ᆠ�ᆠ盐ᨨ�ᨨ  �   �盐矄 ҈ 犨ᨨ矄�矄꾀  鼀矄矄矄鼀 鼀矄ᆠ�泐 꾀�矄� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄  �矄� ᆠ�ᆠ盐ᨨ� ᨨ  �盐矄 ᨨ盐    �ᨨᨨ  �├� �ᆠ  ��矄 꾀⏌ �矄 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰

҈ 

㡰 ҈

ᆠ㡰 

҈ 



҈ 꾀矄��矄ᨨ� �� ᆠ�ᆠ盐ᨨ� ��   ᨨ鼀   矄盐 ᆠ矄盐ᆠ    犨  �矄  �盐矄ᨨ   꾀矄矄盐鼀� �   ᆠᨨ  矄鼀ᨨ矄  ᆠ   �ᆠ    鼀� �鼀盐鼀 � ᆠ矄 �    矄 ⼄盐�  矄ᨨ     矄� ᆠᨨ盐  矄ᆠ ᨨ鼀   ���ᨨ  � ᨨ  �矄 ᲼㝐� ҈҈ ҈黨ᔼ桌 㡰 ᆠ㡰

gR gR 

㡰 㡰



gR

(

㡰

� ⏌ 







㜠҈

ᆠ㡰 㡰 � � ҈ 꾀 矄ᨨ 盐ᨨ 鼀矄矄鼀�矄犨ᨨ├� �ᨨ 矄�ᨨ�� �    �矄 ᆠ  ᨨ鼀  Ἐ矄矄盐 ᆠ  �盐矄 ᨨ   �矄 犨 ��矄鼀矄矄�矄㝐 ���ᨨ 盐 ෌ᨨ  矄ᨨ 盐�矄 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ᨨ矄� ᆠ矄ᨨ 盐 矄犨�� 矄矄 ෌㝐鼀

㡰

+ 㡰

ᆠ㡰

෌ =

)



< ෌


10 Subjective Problems ҈ 꾀ᆠ泐ᆠ�ᆠᨨᆠ矄矄ABCA矄 ᨨ犨 �  V㜠T ��鼀 ��㡰�矄  ᨨ鼀 犨� ᆠᨨ 矄 鼀矄矄ᨨ  � �矄和 ᨨ犨  矄鼀ᨨᆠ矄矄ᨨ P㜠V ��鼀 ᲼҈黨҈㜠㝐├矄桌  

҈ ҈



ᔼ   ��盐CA�矄ᨨ V㜠 �矄 BC�矄 ᨨ T㜠 �矄㡰

WWW.JEEBOOKS.IN

EBD_8341 P-108

Physics

Topic-2 : Specific Heat Capacity and Thermodynamical Processes 1 1.

MCQs with One Correct Answer

Three different processes that can occur in an ideal monoatomic gas are shown in the P vs V diagram. The paths are lebelled as A ® B, A ® C and A ® D. The change in internal energies during these process are taken as EAB, EAC and EAD and the workdone as WAB, WAC and WAD. The correct relation between these parameters are : [Main 5 Sep. 2020 (I)]

D C

P A

2.

3.

4.

5.

6.

the gas molecule changes from t1 to t2. If

T2

T1

V (a) EAB = EAC < EAD, WAB > 0, WAC = 0, WAD < 0 (b) EAB = EAC = EAD, WAB > 0, WAC = 0, WAD > 0 (c) EAB < EAC < EAD, WAB > 0, WAC > WAD (d) EAB > EAC > EAD, WAB < WAC < WAD In an adiabatic process, the density of a diatomic gas becomes 32 times its initial value. The final pressure of the gas is found to be n times the initial pressure. The value of n is : [Main 5 Sep. 2020 (II)] 1 (a) 32 (b) 326 (c) 128 (d) 32 A balloon filled with helium (32°C and 1.7 atm.) bursts. Immediately afterwards the expansion of helium can be considered as : [3 Sep. 2020 (I)] (a) irreversible isothermal (b) irreversible adiabatic (c) reversible adiabatic (d) reversible isotherm7al A thermodynamic cycle xyzx is shown on a V-T diagram.

(a) 2 7.

8.

9.

The P-V diagram that best describes this cycle is: (Diagrams are schematic and not to scale) [Main 8 Jan. 2020 I]

(a)

(b)

Cp Cv

= g for this

t2 gas then a good estimate for t is given by: 1 [Main 7 Jan. 2020 I]

T1>T2 B

A litre of dry air at STP expands adiabatically to a volume of 3 litres. If g = 1.40, the work done by air is: (31.4 = 4.6555) [Take air to be an ideal gas] [Main 7 Jan. 2020 I] (a) 60.7 J (b) 90.5 J (c) 100.8 J (d) 48 J Under an adiabatic process, the volume of an ideal gas gets doubled. Consequently the mean collision time between

(b)

1 2

(c)

æ 1ö çè ÷ø 2

g

(d)

æ 1ö çè ÷ø 2

g +1 2

A sample of an ideal gas is taken through the cyclic process abca as shown in the figure. The change in the internal energy of the gas along the path ca is – 180 J, The gas absorbs 250 J of heat along the path ab and 60 J along the path bc. The work down by the gas along the path abc is: [Main 12 Apr. 2019 I]

(a) 120 J (b) 130 J (c) 100 J (d) 140 J A cylinder with fixed capacity of 67.2 lit contains helium gas at STP. The amount of heat needed to raise the temperature of the gas by 20oC is : [Given that R = 8.31 J mol – 1 K – 1] [Main 10 Apr. 2019 I] (a) 350 J (b) 374 J (c) 748 J (d) 700 J One mole of an ideal gas passes through a process where é 1 æ V ö2 ù pressure and volume obey the relation P = P0 ê1 - ç 0 ÷ ú . êë 2 è V ø úû Here Po and Vo are constants. Calculate the charge in the temperature of the gas if its volume changes from Vo to 2Vo. [Main 10 Apr. 2019 II]

(a)

1 Po Vo 2 R

(b)

5 Po Vo 4 R

3 Po Vo 1 Po Vo (d) 4 R 4 R 10. Following figure shows two processes A and B for a gas. If DQA and DQB are the amount of heat absorbed by the

(c)

(c)

(d)

WWW.JEEBOOKS.IN

P-109

Thermodynamics

矄泐矄鼀� 犨ᨨᆠ矄矄 D꾀 Dᆠ  �矄 �

�   ��矄矄ᆠ�泐   ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰 D턼꾀D턼 D꾀D

҈ 졠 鼀ᨨᨨ  � 鼀ᨨ ᨨᨨ鼀�ᆠ�矄�矄├ ᨨ �   꾀ᔴ꾀矄矄 ᨨ犨 �   ��鼀 鼀 �鼀盐鼀 鼀盐�  泐 �矄ᨨ �  ᔴ�矄��

 泐 ᲼㝐� 졠 � 꾀�҈҈桌

㡰 D턼꾀>D턼 D꾀>D

҈



 꾀

ᆠ㡰 D턼꾀>D턼 D꾀㦨D ҈҈





㡰 D턼꾀㦨D턼錐 D꾀㦨D 꾀 鼀泐� 矄盐 矄矄ᆠᨨ � 矄҈��ᨨ 犨 ᔴ

  � ᨨ鼀 矄矄�矄盐鼀 ᨨ盐 ��ᆠ泐꾀 ᆠ�ᨨ ᨨ 犨盐 矄� ᨨ�ᆠ  矄ᨨ矄  ᔴ�矄  鼀矄矄ᨨ ᨨ 犨犨�ᆠᨨ矄 ᨨ   ᨨ ᨨ� �ᨨ ᨨ 犨㦨҈맔҈├�҈    ᨨ  盐矄�ᨨ ᨨ 犨㦨맔҈�├�҈㡰 ᲼㝐� 꾀�҈黨ᔼ桌 㡰 ҈�� 㡰 � ᆠ㡰 ҈� 㡰 ��

��  ��鼀矄 ᨨ犨矄 ᨨ盐ᨨᆠ矄矄矄�.e.�矄ᨨᆠ ᨨ�ᆠ �矄ᨨ�ᆠ�矄ᨨ 鼀  ��ᆠ ᆠᨨᆠ矄矄�� 鼀  ᨨ  ᨨᆠ矄矄矄�  矄鼀ᨨ �矄�� 泐 ᲼㝐� 꾀҈黨ᔼᔼ桌







㡰 �   㡰 �         � �   ᆠ㡰 㡰 ҈  ҈䰘 Ἐ Ἐ鼀ᨨ矄ᨨ  � �矄盐 �ᨨ矄ᨨᆠ矄矄꾀®矄 矄 ᨨ犨 �   ��盐 鼀 �鼀盐鼀鼀盐ᨨ  �矄 盐� � ᨨᆠ矄矄犨� ᲼㝐� ҈桌   

꾀 

   黨  黨  黨    㡰 㡰 ᆠ㡰 㡰 

  ҈ �ᨨᨨ 犨ᨨ├ ᨨ 泐 � 鼀ᨨ ᨨᨨ鼀�ᆠ�矄ᨨ  矄盐� ᨨ��  �矄ᨨ�ᆠᨨᆠ矄矄�矄 ᲼㝐� 졠 � 꾀�黨҈桌 ҈

㡰  ᆠ 㡰 ᆠ ᆠ㡰  ᆠ 㡰 ᆠ ᨨ �� ᆠ泐ᆠ�ᆠᨨᆠ矄矄ᔴ꾀矄矄 ᨨ犨  ᨨ�矄  犨ᨨ├ ᨨ �矄 ᲼㝐� ҈ ҈黨ᔼ桌 





� 

 㡰  



҈ ҈

҈





�  鼀㡰

㡰  㡰 ҈ ᆠ㡰 ҈ 㡰 � 꾀���  �ᨨ鼀�ᆠ� �矄盐 �ᨨ矄  ��ᆠᨨᆠ矄矄 ᨨᨨ鼀鼀盐 �ᨨ 犨 鼀盐  ᨨ盐鼀 ᨨ �矄ᨨᆠ矄矄�矄  㦨ᆠᨨ 矄    �矄 ᲼㝐�  ҈҈   ҈黨 ᔼ桌    � 㡰 ᆠ㡰 㡰 � �    鼀ᨨᨨ  � 鼀ᨨ ᨨᨨ鼀�ᆠ�矄�矄  ᆠᨨ 矄  矄矄盐ᨨ ҈鼀 ᨨ鼀 ᔴᨨ黨 ᔴ␔ᨨ├ ᨨ 泐�矄�矄 ᆠᨨ矄ᨨ ෌矄ᆠᨨ 矄  㦨҈⏌鼀ᨨ㜠⧤㡰 ᲼㝐�  ҈   ҈黨 ᔼᔼ桌 㡰 �҈ 㡰 黨҈ ᆠ㡰 ҈ 㡰 䰘

㡰

҈�



    㡰 ᆠ㡰 㡰 �  �  ҈黨 꾀�矄�矄 ᆠᨨ矄 � ᆠ泐� 犨� 鼀ᨨ �ᆠ�ᨨ 矄矄 �矄ᨨ ᔼ矄� �� 鼀ᨨ 泐 鼀�ᆠ矄矄矄盐�㦨҈�  ᨨ盐鼀�㦨҈鼀ᆠ  �矄ᨨ � 矄 㦨 ҈⏌㡰맔҈�  㦨맔҈鼀�   ��ᆠ⼄盐矄�㜠 矄�ᆠ ᨨᆠ矄矄 矄盐ᆠ     � 㦨 ᆠᨨ 矄  ᔴᨨ 矄�   ᨨ  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄 � �矄 矄泐矄鼀 ᨨ鼀 矄鼀� ��矄ᨨ 矄鼀 � 矄� 犨ᨨ 矄矄 �矄ᨨ�ᆠ  矄�ᨨ � ᨨᨨ犨 泐 �矄ᨨᆠ ᨨ�ᆠ �矄ᨨᨨ盐鼀�ᆠ㡰ᨨᆠ矄矄ᨨ盐鼀  鼀ᨨ盐 ᨨ   矄盐�  ᨨ   矄泐矄鼀 �    犨ᨨ㜠矄 ᨨᆠ矄矄 �矄 ᨨ �鼀泐 ᲼꾀 ҈桌 㡰 ҈҈ 㡰 黨 ᆠ㡰 � 㡰 ҈  ᔴᨨ 矄�    �  �矄 ᆠᨨ �  �    �矄ᨨ  ᆠᨨ矄 ᆠ 鼀꾀矄 �矄盐 �ᨨ矄  ��ᆠ  矄�ᨨ   ��鼀ᨨ ᆠᨨ�矄�ᨨ 犨 鼀ᨨᆠ盐矄� ᆠ矄矄 as V⼄犨 �矄 ᨨ盐鼀ᨨ  �矄 盐ᨨ ⼄

㡰

ᔴ ö æ �矄 ç g = ᲼㝐� ҈�桌 ÷ ᔴ ø è g + � g - � g +҈ g -҈ 㡰 㡰 ᆠ㡰 㡰     ҈ ᔴᨨ 矄� 矄 �ᆠ矄 ᨨ  �盐矄 鼀盐 

ᆠ├ᨨ 泐 ��ᨨ � 矄� �ᆠ ᆠᨨ 矄�  矄

� �矄ᨨ  ᨨᨨ 矄犨� �   �泐盐 �ᨨ盐鼀  ҈æö 盐㦨 µ  矄矄盐  = ç ÷ ᔼ  矄  ᨨ犨  è  ø 盐 �ᨨ矄  ��ᆠ  矄�ᨨ  �ᨨ 犨 

  �矄 ᲼㝐� ҈�桌

WWW.JEEBOOKS.IN

EBD_8341 P-110

҈ ҈ 㡰 µ  ᆠ㡰 µ 㡰 µ 꾀 � �矄�ᨨ矄 ᨨ盐� 矄�ᆠ泐ᆠ®®ᆠ® 矄 㜠  ��鼀矄 ᨨ犨 ᨨ犨ᨨᆠ矄矄 ® ®ᆠ ��ᆠ 㡰



Physics

µ











ᆠᨨ矄ᨨ � �㜠 ��鼀 ᨨ ᨨᆠ矄矄�矄  ��盐矄矄ᆠ 鼀�ᆠ  ᨨ 犨 ᨨ矄ᆠ㡰 ᲼㝐� 졠 � 꾀�҈҈�桌 



㡰



ᆠ 

㡰



 ᆠ



� 꾀  �  �矄  鼀ᨨ矄 �ᆠ 矄矄盐 �矄  ��ᆠ泐 ᆠᨨ鼀矄矄  矄ᨨ  �矄  矄�泐ᆠᨨ鼀矄�鼀矄ᨨ �矄 � ��盐ᔼ   � 矄矄盐ᨨ �矄�矄҈鼀ᨨ矄 矄  盐ᨨ �gᨨ  �矄�矄 ᲼㝐� 졠 � 꾀�҈桌 㡰 ҈� 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈  ��ᨨ  �盐鼀�矄和 �矄 ��ᆠ泐ᆠᨨ鼀矄矄 ᨨ䰘� ├� � � ��鼀盐ᨨ ҈ 犨ᨨ├ ᨨ �  ᨨᆠ矄矄�矄 ᲼㝐� ҈҈桌 ҈� 黨 黨  RT 㡰 RT 㡰 㡰 ᆠ㡰 RT RT  ҈  ҈  ҈  ҈ 䰘 꾀 � �矄�矄� ��泐P҈V҈�矄   ᨨPV   ᆠᨨ鼀矄矄  ��ᆠ泐ᨨ 矄鼀ᨨ盐鼀V҈ 矄矄盐 P ᔼ  W �矄     犨ᨨ├  ᨨ  泐   �矄 �

ᆠᨨ鼀ᨨᆠ矄矄犨 �ᆠ ᨨ   ᨨᨨ犨� ��矄盐 ᲼和桌 㡰 W>錐P>P҈ 㡰 W錐P>P҈ ᆠ㡰 W>錐PP҈ 㡰 W錐PP҈  PT ��鼀 ᨨ � �矄�矄矄 ᨨ犨 �   ��盐 犨 AC�矄  ��ᆠᨨᆠ矄矄 �  ᆠᨨ矄ᨨ � � PV ��鼀 ᲼和桌





A

P 









C

B

ᆠ㡰











T A







졠 鼀ᨨᨨ  �ᨨ鼀�ᆠ� �矄盐 �ᨨ矄ᆠ泐ᆠ�ᆠᨨᆠ矄矄 꾀ᔴ矄矄 ᨨ犨 �  ��盐 ᨨᆠ矄矄ᔴ�矄 ��ᆠ  鼀盐矄꾀 ᔴ⧤⧤ ⧤ 矄ᆠ�泐ᔴ ᨨᨨ矄 ᆠᨨᆠ矄鼀 ᲼㝐� ҈桌

A

P

P

㡰

C

B

㡰

V

V

A

A

P



P

ᆠ㡰

⧤

C

B



B C

V





⧤

├ ᔴ

B

C

V

黨 꾀 � �矄�矄├  ᨨ盐�  ᆠ泐ᆠ A ® B ® C ® A  矄矄 ᨨ犨 �   ��盐ᔼ    矄盐� ᨨ �矄 �  ᆠ泐ᆠ�矄� 犨ᨨ├ ᨨ 泐 �矄�  ᨨᆠ矄矄 ᲼和桌 C ® A �矄 C B  㡰�   鼀 㡰



 㡰 ᆠ  �� �   �泐� 犨 ᨨᆠ泐ᆠ�ᆠᨨᆠ矄矄 �矄�  㡰 ᆠ  �� �   �泐�  ᨨᆠ矄矄ᔴ꾀�矄䰘  ᆠ㡰 ᆠ  �� �   �泐�  ᨨᆠ矄矄꾀�矄㜠�  㡰 ᆠ  �� �   �泐�  ᨨᆠ矄矄ᔴ�矄�  盐� �  ��ᆠᆠᨨ鼀矄矄�ᨨ ᨨ 犨ᨨ├�矄 ᨨ ᨨ

鼀ᨨ矄ᨨ  �ᨨ鼀�ᆠ� �矄ᨨ 盐ᆠ�矄ᨨ盐鼀泐 �奠 ᆠ  �� �矄鼀盐�矄 泐 㦨⧤҈鼀ᨨ҈㡰 ᲼㝐� 졠 � 꾀�҈҈҈桌 㡰 ⧤ 㡰 ⧤ ᆠ㡰 ⧤ 㡰 ҈⧤

㡰҈

҈

ᆠ㡰҈�

A

㡰  ⏌鼀㡰 ҈  P㜠V ᨨ矄 ᨨ 犨ᨨ�矄矄 盐� �  ��ᆠ ᨨᆠ矄矄矄  矄 ᨨ犨  �    ��盐 ᨨ矄 ҈    矄 ᨨ盐  ᆠᨨ矄ᨨ 矄ᆠ�泐ᨨ ᲼҈和桌  㡰  졠 㡰 졠  ᆠ㡰  꾀 㡰 졠 

҈ 



WWW.JEEBOOKS.IN

P-111

Thermodynamics

҈

和� � 犨�    矄鼀 � �� ᆠᨨ ��ᨨ 矄   �  �矄   矄 ᨨ鼀ᨨ盐鼀V҈ᨨV�   �  犨泐矄  犨ᨨ├  ᨨ  泐   �矄 �矄 W҈ �    ᨨᆠ矄矄 �矄 盐泐 �矄ᨨ 鼀W� 盐泐�矄ᨨ�ᆠ W� 盐泐 ��ᆠ



᲼和桌 㡰 W>W҈>W

y ᔼ矄ᨨ�ᆠ

㡰 W>W>W҈

W ᔼ矄ᨨ 鼀 ␔҈ 꾀 ��ᆠ ␔

P

ᆠ㡰 W҈>W>W 㡰 W҈>W>W 





æ L҈ ö ç ÷ è L ø

⏌

㡰

L҈ L ⏌

æ L ö ÷ ᆠ㡰 㡰 ç è L҈ ø 꾀�� ⼄盐 �泐ᨨ � �矄�矄矄矄盐P 矄ᨨ盐 鼀盐T �矄ᨨ 鼀盐├鼀ᨨ 盐盐矄ᨨ  �矄�矄 ᲼҈黨黨和㜠㝐├矄桌  P 㡰 㡰 P   P 㡰 P ᆠ㡰  꾀 � 鼀ᨨ ᨨ鼀�ᆠ�矄�矄├ ᨨ盐  ᆠ泐ᆠABCDA 矄矄 ᨨ犨 �  PV ��鼀 矄 ��㡰 犨ᨨ├ ᨨ  盐� � ᆠ泐ᆠ�矄 ᲼҈黨㜠҈㝐├桌 P 㡰 PV P, V P, 2V 㡰 PV B C L L҈



҈ PV  㡰 ᨨ

ᆠ㡰

2 �

x

꾀 鼀ᨨ ᨨ鼀�ᆠ �  �矄 � ��泐 鼀盐 T҈ �矄  ᆠᨨ矄 � ᆠ泐�  � 犨�  �ᆠ�ᨨ 矄矄�矄ᨨ   �矄�矄ᨨ犨 ᨨ   ��ᆠ泐ᨨ鼀盐T 泐矄� � �矄ᨨ 矄盐  泐ᔼ L҈ L  � ᨨ  �矄ᆠᨨ盐鼀  ᨨ    矄�ᨨ 矄ᆠ�泐 T҈    T �矄�� 泐 ᲼和桌  㡰



V

꾀矄矄盐鼀� ��ᨨ �ᨨ鼀�ᆠ� �矄鼀 盐ᨨ ��� 鼀ᨨᆠ盐矄 ᆠ  �� �矄�   �泐 盐� � �矄 ᨨᆠ矄矄ᆠᨨ鼀矄ᨨ盐ᨨX├ 盐ᨨ Xᨨ  矄 � ��矄힘힘힘힘힘힘힘힘 [Main 2 Sep. 2020 (I)] 䰘 和� �鼀盐⧤ᨨ 鼀ᨨᨨ  �  �ᨨ鼀�ᆠ �矄 g㦨҈㡰�矄 �矄ᆠᨨ鼀矄矄  ��ᆠ泐 ᨨ鼀ᨨ盐鼀 ҈ ҈ᨨ㦨  ᔼ�矄  ᨨ犨 ᨨ  �矄ᨨ�ᆠ泐ᨨ ҈ ᨨ盐鼀ᔼ  ᨨᆠ矄矄矄 ⼄盐矄�㜠矄�ᆠ 

  � 鼀盐ᨨ  �矄 �  ⧤㡰�矄 ᨨ  矄 � �㡰힘힘힘힘힘힘 ᲼㝐� 黨 ᔼᔼ桌  ᔴᨨ 矄� ᨨ 鼀ᨨᨨ  �盐鼀�矄 ᆠᨨ矄 � ᆠᨨ �  � ��矄矄盐P҈ ᨨ盐鼀V҈ᔼ  矄�矄ᨨ 鼀泐 ᨨᨨ盐鼀V҈꾀  �矄 �矄  矄 ��ᆠ泐  �矄ᨨ盐鼀ᆠᨨ鼀矄V҈ 犨ᨨ├ ᨨ 泐 �矄 盐� ��矄ᨨ 鼀  ��ᆠ  矄�ᨨ ᨨᆠ矄矄矄 W�sᨨ = f   W�sᨨ Wad�a矄ᆠ�泐ᔼ  �ᨨ W ad�a   f�矄힘힘힘힘힘힘힘힘 ᲼꾀 桌 黨 꾀矄 �ᆠ盐� 矄� 犨 矄 �盐矄R ├  矄矄盐� 矄�  盐  犨矄矄盐ᨨ p 盐 ᨨ犨�矄ᆠᨨ鼀矄矄  �泐�   �㜠 �ᆠ鼀

矄ᨨ �矄 �盐矄ᆠᨨ鼀矄 R  a㡰 ᨨ a = R  鼀� �盐 ᨨ  犨ᨨ├ ᨨ �  ᨨᆠ矄矄�矄�� 泐 犨 X�矄ᆠᨨ 矄  g = C p ⏌ Cv = ҈⏌   盐 ᨨ X�矄힘힘힘힘힘힘힘힘 ᲼꾀 桌 4

 꾀 � �矄犨� 矄矄盐Pᨨ盐鼀V 鼀盐T �矄   �矄ᨨ 鼀泐ᨨᨨ盐鼀V  � 矄矄盐 P�ᔼ  矄鼀�矄�矄    ��ᆠ泐ᨨᨨ盐鼀 V  � 矄矄盐�矄Pa �ᨨᨨ  矄ᆠ� �ᆠ 矄 Pa ᨨ  �矄�矄҈䰘 �ᨨ P �矄 ᲼҈黨黨㜠㝐├矄桌 ҈

5 A P, V

D

P,V V

Integer Value Answer

True / False

҈ ᆠ盐矄A B�   ��盐矄 ᨨ犨 P㜠V� 矄 ᨨ

�矄ᨨ 鼀   ��ᆠᨨᆠ矄矄 ᨨ � �矄  �矄ᨨ 鼀ᨨᆠ矄矄�矄矄  泐 ᆠ盐A ᲼҈黨�㜠㝐├矄桌

҈ ᨨ  �矄� ��ᨨ盐鼀ᔼ  � ��鼀盐ᨨ  �矄�矄 T� �

꾀 �ᨨ鼀�ᆠ� �矄�矄ᆠᨨ鼀矄矄  ��ᆠ泐ᨨ

P

3

Numeric Answer

꾀  �� ├矄� �鼀ᨨᨨ � ᔴ ҈鼀 ᆠᨨ鼀矄矄矄� ��ᆠ泐ᨨ҈⏌҈ ᨨ  ᨨ��� ᨨ盐鼀

A B

⧤� 㡰   � 鼀盐�矄  T�   盐ᨨ a�矄 ᲼҈桌



Fill in the Blanks

6

V MCQs with One or More than One Correct Answer

 꾀鼀� 盐ᨨ � �矄ᆠᨨ � � ��鼀ᨨ矄ᨨ 鼀ᨨ ᨨ鼀�ᆠ �矄 ҈鼀ᨨᨨ ���  �ᨨ鼀�ᆠ�矄�矄� ��泐矄矄盐

WWW.JEEBOOKS.IN

EBD_8341 P-112



Physics

Pᨨ盐鼀V 鼀盐Tᔼ  �矄鼀� 盐�矄  ��ᆠ泐ᆠᨨ鼀矄矄  ᨨ ᨨ盐鼀 V⏌      ᆠᨨᆠ矄鼀  矄㡰�矄⏌ ෌� ҈㦨錐黨錐R�矄 �矄 ᆠᨨ 矄 㡰 ᲼꾀 ҈黨桌 㡰 犨ᨨ├␔ ᨨ  盐� � ᨨᆠ矄矄�矄҈RT 㡰  �  矄矄盐 ᨨ    �矄 鼀� 盐   ᆠᨨ鼀矄矄�ᨨ �矄� 犨 黨P ҈P ᆠ㡰 �├� �ᆠ �泐ᨨ  �矄鼀� 盐  ᆠᨨ鼀矄矄�ᨨ �矄� 犨 ҈RT ҈黨RT 㡰 꾀 ��ᆠᆠᨨ 矄 ᨨ  �矄鼀� 盐�矄҈ 졠  鼀ᨨ ᨨ   鼀ᨨ ᨨ鼀�ᆠ �  �矄 �ᨨ矄  ᨨ盐�    鼀ᨨ 泐 鼀�ᆠ ᆠ泐ᆠ 矄 矄 ᨨ犨  �    ᨨ盐鼀 矄盐矄 鼀盐 VT㡰 ��鼀 ᆠᨨᆠ矄鼀  矄㡰�矄⏌ ᲼ �矄 �矄ᆠᨨ 矄  ᲼꾀 ҈黨桌



V



V



҈

T⏌

T

T⏌

T

T

㡰 ␔ᨨ├ ᨨ  �   �矄  鼀ᨨ 泐 鼀�ᆠ ᆠ泐ᆠ

҈ RT  㡰  ᨨ  鼀ᨨ 泐 鼀�ᆠ ᆠ泐ᆠ  ��矄 ᨨ 泐 �矄ᨨᆠ ᨨ�ᆠ  ��ᆠᨨᆠ矄矄矄 ᆠ㡰 �ᨨᨨ   矄  盐� �ᨨᆠ矄矄矄҈® ҈ ®  ®  ®  ® ҈㡰 �矄 W =

Q҈® � =  ®�矄 Q  ®

㡰 �ᨨᨨ    矄  盐� �ᨨᆠ矄矄矄 ҈ ® Q҈® ҈ =  ®�矄 Q  ®



졠 鼀ᨨᨨ  � �矄� � ��矄꾀盐 �ᨨ矄ᆠ泐ᆠ�ᆠ ᨨᆠ矄矄꾀ᔴ꾀矄矄 ᨨ犨 �   ��盐ᔼ矄矄矄盐꾀�矄 Pᔴ ᨨᨨ矄 ᆠᨨᆠᨨ�ᨨ 矄㡰 ᨨ鼀  ᨨᨨ犨� � ᲼҈桌 V  V V



꾀 T

T 㡰 ᔼ   ��矄꾀  矄鼀 㡰 ␔ᨨ├ ᨨ 泐 �矄� ᨨᆠ矄矄꾀�矄PVln P ᆠ㡰 矄矄盐ᔴ�矄  T 㡰 鼀盐ᔴ�矄 

�  ��盐矄 ᨨ犨矄 P㜠Vᨨᨨ  � �矄├  ᨨ盐� ᆠ泐ᆠABCDA ABC �矄矄鼀�㜠ᆠ�ᆠ CDA�矄  ᨨ  �矄   ᲼黨桌 P  

A

B

D

҈ 

C ҈



 V

㡰  ᨨᆠ矄矄 盐� �  A®B�矄�矄ᨨ 鼀 㡰  ᨨ犨矄ᨨ盐ᨨ  �矄 盐� �  B®C®D ᆠ㡰 犨ᨨ├ ᨨ  盐� �  A®B®C�矄 ᨨ 㡰 ᨨ矄��犨ᨨ├�矄 ᨨ 泐 �矄�  ᆠ泐ᆠABCDA  ᨨ � �矄 ᲼҈黨黨㜠㝐├矄桌 㡰  ᆠ  �� �   �泐� ᆠᨨ 矄 矄矄盐 ᨨᆠ矄矄 ᨨ鼀 鼀盐 T҈ ᨨ T �矄⼄盐 ᨨnCv TT҈㡰犨 Cv�矄 鼀ᨨ矄ᆠ� �ᆠ ᆠᨨ 矄  ᨨ盐鼀 n  盐鼀ᨨ 鼀ᨨ矄ᨨ  �矄 㡰  ᆠ  �� �   �泐ᨨ  �矄  犨ᨨ├ ᨨ 泐 �矄⼄盐� 鼀� �盐 �   ��ᆠ ᨨᆠ矄矄 ᆠ㡰  �   �泐 ᨨ矄 ᨨᆠ  ��  �矄ᨨ 鼀 ᨨᆠ矄矄 㡰 ᨨ �矄  ᨨ鼀ᨨ �   ��ᆠᨨᆠ矄矄 7

Match the Following

䰘 㝐ᆠ     鼀ᨨ 泐 鼀�ᆠ ᨨᆠ矄矄矄├� � ᆠ �   矄泐矄鼀犨�  ᆠᨨᆠᆠᨨ ��ᨨ 矄ᔼ  DQ�矄  矄盐� DW�矄 犨ᨨ├ ᨨ  DU�矄ᆠ  ��

�   �泐ᨨ  矄泐矄鼀 ᲼㝐� 和 ᔼᔼ㡰桌 ᨨᆠ矄矄 ᔴᨨ ��ᨨ

ᔼ㡰 꾀 ��ᆠ 꾀㡰 DW㦨 ᔼᔼ㡰 ᔼ矄ᨨ 鼀 㡰 DQ㦨 ᔼᔼᔼ㡰 ᔼ矄ᨨᆠ ᨨ�ᆠ ᔴ㡰 DU ¹  DW ¹ 

DQ ¹  ᔼ㡰 ᔼ矄ᨨ�ᆠ 㡰 DU㦨 㡰 ᔼ㡰㜠 꾀㡰 ᔼᔼ㡰㜠 㡰 ᔼᔼᔼ㡰㜠 㡰 ᔼ㡰㜠 㡰 㡰 ᔼ㡰㜠 㡰 ᔼᔼ㡰㜠 꾀㡰 ᔼᔼᔼ㡰㜠 㡰 ᔼ㡰㜠 ᔴ㡰 ᆠ㡰 ᔼ㡰㜠 꾀㡰 ᔼᔼ㡰㜠 꾀㡰 ᔼᔼᔼ㡰㜠 㡰 ᔼ㡰㜠 ᔴ㡰 㡰 ᔼ㡰㜠 㡰 ᔼᔼ㡰㜠 㡰 ᔼᔼᔼ㡰㜠 꾀㡰 ᔼ㡰㜠 ᔴ㡰  ᔼ  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄ᨨ  � 鼀ᨨ ᨨ鼀�ᆠ�矄   � � �矄�鼀  矄ᨨ  泐 �矄�矄 ��  泐

D犨 T�矄鼀盐ᨨ  矄泐矄鼀 D�矄  � � �矄�鼀ᆠ  ��  鼀ᨨ 泐 鼀�ᆠ⼄盐 �泐Xᨨ   矄泐矄鼀 ᨨ  鼀ᨨ ᨨ  鼀ᨨ ᨨ鼀�ᆠ �  �矄 æT ö æV ö  X = ҈ ç ÷ + ҈ ç ÷  �矄�矄ᆠᨨ 矄 V  T è Aø è VA ø �矄ᨨ盐鼀ᨨ �矄T꾀 V㜠ᆠᨨ 矄 矄

 �矄㜠ᔼ ᨨ犨 ��矄 矄ᨨ鼀 ⼄盐 ��矄 � ᨨ  �   ᨨᆠ矄矄 �矄㜠ᔼᔼ��矄矄ᨨ鼀ᨨ矄矄�盐矄ᨨ  矄 ⼄盐 ��矄 ᲼꾀 ҈黨桌

WWW.JEEBOOKS.IN

P-113

Thermodynamics

�矄㜠ᔼ ᔼ㡰

␔ᨨ├ ᨨ 泐 

矄泐矄鼀�  ᨨᆠ矄矄 ҈®® ᔼᔼ㡰 ᔴ  �� �    �泐�  ᨨᆠ矄矄 ҈®® ᔼᔼᔼ㡰  矄ᨨ  泐  矄泐矄鼀�

ᨨᆠ矄矄҈®® ᔼ㡰  矄ᨨ 泐  矄泐矄鼀 � ᨨᆠ矄矄҈®

�矄㜠ᔼᔼ ҈ RT ⏌ ln  㡰 

턼㡰

҈ RT 

㡰 

和㡰

 

 

҈ 㡰 

 졔l 㡰  � 㡰

  ᔼ  ᨨᆠ矄矄ᆠ� ᨨ盐ᨨ ᨨ 鼀ᨨᨨ 鼀ᨨ ᨨ鼀�ᆠ�  ҈ �矄�矄矄 ᨨ犨 �   ��盐㜠 ��鼀犨� PV㦨 RT   ᆠᨨᆠ鼀ᆠ �矄 P P  

P

 ҈ V

黨

 V

V

㡰 ᔼ®턼ᔼᔼ® ᔼᔼᔼ®和ᔼ® 㡰 ᔼ®和ᔼᔼ® ᔼᔼᔼ®턼ᔼ®

ᆠ㡰 ᔼ®턼ᔼᔼ® ᔼᔼᔼ®ᔼ® 㡰 ᔼ®턼ᔼᔼ®和ᔼᔼᔼ® ᔼ® ᔼ  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄ᨨ  � 鼀ᨨ ᨨ鼀�ᆠ�矄   � � �矄�鼀  矄ᨨ  泐 �矄�矄 ��  泐

D犨 T�矄鼀盐ᨨ  矄泐矄鼀 D�矄  � � �矄�鼀ᆠ  ��  鼀ᨨ 泐 鼀�ᆠ⼄盐 �泐Xᨨ   矄泐矄鼀 ᨨ  鼀ᨨ ᨨ  鼀ᨨ ᨨ鼀�ᆠ �  �矄 æT ö æV ö  X = ҈ ç ÷ + ҈ ç ÷ R�矄�矄ᆠᨨ 矄 V  è TA ø è VA ø �矄ᨨ盐鼀ᨨ �矄T꾀 V꾀ᆠᨨ 矄 矄

 �矄㜠ᔼ ᨨ犨 ��矄 矄ᨨ鼀 ⼄盐 ��矄 � ᨨ  �   ᨨᆠ矄矄 �矄㜠ᔼᔼ��矄矄ᨨ鼀ᨨ矄矄�盐矄ᨨ  矄 ⼄盐 ��矄 ᲼꾀 ҈黨桌 �矄㜠ᔼ �矄㜠ᔼᔼ ҈ RT ln ᔼ㡰 ␔ᨨ├ ᨨ 泐  㡰  矄泐矄鼀�  ᨨᆠ矄矄 ҈®® ҈ RT ᔼᔼ㡰 ᔴ  �� �   턼㡰   �泐�  ᨨᆠ矄矄 ҈®® ᔼᔼᔼ㡰  矄ᨨ  泐 㡰 

 矄泐矄鼀� ᨨᆠ矄矄 ҈®® ᔼ㡰  矄ᨨ  泐 和㡰  矄泐矄鼀�  ᨨᆠ矄矄 ҈®

 

 

҈ 

 졔l 㡰  � 㡰

  ᔼ  ᨨᆠ矄矄ᆠ� ᨨ盐ᨨ ᨨ 鼀ᨨᨨ 鼀ᨨ ᨨ鼀�ᆠ� 



҈ �矄�矄矄矄 ᨨ犨 �  TV㜠 ��鼀犨� 㦨

    ᆠᨨᆠ鼀ᆠ �矄

㡰 ᔼ®ᔼᔼ® ᔼᔼᔼ®턼ᔼ®

㡰 ᔼ®和ᔼᔼ® ᔼᔼᔼ®턼ᔼ® ᆠ㡰 ᔼ®ᔼᔼ® ᔼᔼᔼ® ᔼ® 㡰 ᔼ®ᔼᔼ® ᔼᔼᔼ® ᔼ®和 � 졠  鼀ᨨ ᨨ   鼀ᨨ ᨨ鼀�ᆠ �  �矄 盐 �ᨨ矄 ᨨ盐  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄矄矄矄 ᨨ犨 矄ᆠ 鼀�ᆠ泐�   㜠 ��鼀ᨨ犨꾀鼀ᨨ � 矄 ᨨ盐ᨨᆠ矄矄矄ᨨ �矄 �矄ᨨ�ᆠᨨ �矄�矄ᨨᆠ ᨨ�ᆠᨨ �矄�矄ᨨ 鼀 ᨨ �矄  ��ᆠ㝐ᆠ  ᨨᆠ矄矄矄鼀 �ᨨ  � �矄㜠ᔼ犨�  ᆠᨨ矄ᨨ � �矄鼀 矄� �矄㜠ᔼᔼ ᲼꾀 ҈桌  ᔼᔼ



ᔼᔼᔼ

ᔼ ᔼ

   턼 

和 㡰 㡰 ᆠ㡰 㡰

ᔼ和Tᔼ ᔼ ᨨᆠ矄矄ᔼ





ᔼ和Tᔼᔼ ␔ᨨ├ ᨨ 泐 �矄 �矄 ᨨ ᔼ ᨨᆠ矄矄ᔼᔼ  鼀盐ᨨ  �矄 鼀� 矄盐 ᆠ  � ᔼ ᨨᆠ矄矄ᔼᔼᔼ  ᨨ �矄 ᆠ  � 犨  �矄 �矄 矄盐ᨨ盐 � �矄 ᔼ ᨨᆠ矄矄ᔼ  ␔ᨨ├ ᨨ 泐 �矄�矄 6P ®錐턼®錐 ®҈錐和® ®҈錐턼®錐 ®錐和® ®錐턼®錐 ®҈錐和® ®錐턼®錐 ®錐和®҈ ҈

WWW.JEEBOOKS.IN

EBD_8341 P-114

Physics

ᔼ EᔴTᔼ졠N和턼Nᨨ�҈� �泐ᨨ�泐鼀ᆠ � � � ᨨ鼀�ᨨ �� �   ᆠᨨ盐鼀 矄ᨨ   ᨨᨨ犨� � 꾀 � �矄�矄盐 �ᨨ� �ᆠ泐ᆠ�ᆠ 鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄�  �  犨泐矄矄矄 ᨨ犨 �  ᆠᨨ矄ᨨ � � ��鼀矄�

ᆠᨨ盐鼀 ᨨ  ᔴᨨ 矄� ᨨ 泐   ᨨ鼀矄҈ᨨ矄␔  ᨨ矄 ᆠᨨ矄ᨨ � �犨ᨨ├ ᨨ ᨨ  矄泐矄鼀  ⼄盐�ᨨ 矄 ᨨ矄�   矄   ᨨ�ᨨ 矄矄盐矄 �  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄矄Ӹ�矄 �ᨨᨨ  ᆠᆠ��矄 ᆠᨨ 矄 矄矄盐 ᆠᨨ 矄 ᨨ盐鼀  盐鼀ᨨ 鼀ᨨ矄�  �矄�矄  ᲼꾀 ҈䰘桌 ᔴᨨ盐鼀 ҈ ᔼ㡰

␔҈® =

ᔴᨨ盐鼀 

҈   - ҈҈ 㡰 g -҈

ᔼᔼ㡰 ␔҈® = - + ҈

�㡰

ᔴᨨ盐鼀 

ᔼ矄ᨨ 鼀

��㡰 ᔼ矄ᨨᆠ ᨨ�ᆠ

㡰



턼㡰



҈



 ҈

 



ᔼᔼᔼ㡰 ␔҈® = 

���㡰 ᔼ矄ᨨ�ᆠ

҈





  ҈ æ ö ᔼ㡰 ␔҈® = -  ç  ÷ è ҈ ø

�㡰

꾀 ��ᆠ

和㡰



 �҈

�

�

�

␔ �ᆠ ᨨ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄ᆠᨨᆠ泐矄 矄  鼀ᨨ 泐 鼀�ᆠᨨᆠ矄矄 �矄盐矄 矄ᆠᨨᆠ�ᨨ �   鼀� �ᨨ ᨨ  矄 ᨨ 矄ᨨ盐 �  � �矄䁸 㡰 ᔼ㡰 ��㡰 턼㡰 㡰 ᔼ㡰 ��㡰 㡰 ᆠ㡰 ᔼᔼᔼ㡰 �㡰 㡰 㡰 ᔼ㡰 �㡰 턼㡰 ␔ �ᆠ  ᨨ  ᨨ    ᨨᨨ犨� � ᨨ�ᨨ 矄 �矄   ᆠᨨᆠ ᆠᨨ鼀� �ᨨ 䁸 㡰 ᔼ㡰 ��㡰 和㡰 㡰 ᔼᔼᔼ㡰 ��㡰 和㡰 ᆠ㡰 ᔼᔼ㡰 �㡰 㡰 㡰 ᔼᔼ㡰 �㡰 㡰 ␔ �ᆠ  ᨨ    ᨨᨨ犨� � ᨨ�ᨨ 矄 �矄   ᨨ 泐 ᆠᨨᆠ 矄 �ᨨ ᨨ ᨨᆠ矄矄� 犨 �ᆠ D㦨D턼D䁸 㡰 ᔼᔼ㡰 �㡰 㡰 㡰 ᔼᔼᔼ㡰 ���㡰 㡰 ᆠ㡰 ᔼᔼ㡰 ���㡰 和㡰 㡰 ᔼᔼ㡰 ���㡰 㡰 졠 鼀ᨨᨨ 鼀ᨨ ᨨ鼀�ᆠ� �矄�矄├ ᨨ �犨ᨨᆠ泐ᆠ�ᆠ ᨨᆠ矄矄矄쟼® ®෌®쟼 쟼® ®®쟼矄矄 ᨨ犨

�   ��鼀 ᨨᆠ矄矄矄� ᨨ 盐泐�矄ᨨᆠ ᨨ�ᆠ �矄ᨨ�ᆠ�矄ᨨ 鼀ᨨ ��ᆠ ᲼꾀 ҈桌

 







 

෌ 

㝐ᆠ   矄� �矄ᔼ犨�  鼀� �盐 矄ᨨ  犨ᨨ├ ᨨ �  �矄 ᔼᔼ  矄ᆠ ᆠᨨᆠ 矄犨 盐矄� �  ᆠᨨ 矄�� ᨨ犨 �矄矄 �矄ᔼ �矄ᔼᔼ  ෌®쟼 ҈ ҈  턼 ෌®    ®   和 ®෌  ҈

WWW.JEEBOOKS.IN

P-115

Thermodynamics

Codes: P (a) 4 (b) 4 (c) 3 (d) 1

Q 3 3 1 3

R 2 1 2 2

(a) Sketch the complete process on a p – V diagram. (b) Find the total work done by the gas, the total change in its internal energy and the final temperature of the gas. [Give your answer in terms of p1, V1, V2, Q and R] 59. One mole of an ideal monatomic gas is taken round the cyclic process ABCA as shown in Figure. Calculate [1998 - 8 Marks]

S 1 2 4 4

P

10 Subjective Problems 55.

56.

A cylinder of mass 1 kg is given heat of 20,000J at atmospheric pressure. If initially the temperature of cylinder is 20°C, find [2005 - 6 Marks] (a) final temperature of the cylinder. (b) work done by the cylinder. (c) change in internal energy of the cylinder (Given that specific heat of cylinder = 400 J kg–1 °C–1, coefficient of volume expansion = 9 × 10–5 °C–1, Atmospheric pressure = 105 N/m2 and Density of cylinder = 9000 kg/m3) A monoatomic ideal gas of two moles is taken through a cyclic process starting from A as shown in figure. The volume ratios are is 27oC.

V VB = 2 and D = 4. If the temperature TA at A VA VA

[2001-10 Marks]

V

VD

D

C

B

VB VA O

A TA

TB T

57.

Calculate, (a) the temperature of the gas at point B, (b) heat absorbed or released by the gas in each process, (c) the total work done by the gas during the complete cycle. Express your answer in terms of the gas constant R. Two moles of an ideal monatomic gas is taken through a cycle ABCA as shown in the P-T diagram. During the process AB, pressure and temperature of the gas vary such that PT = Constant. If T1 = 300 K, calculate [2000 - 10 Marks]

3P0

P0

B

A

C

V0

2V0

V

(a) the work done by the gas. (b) the heat rejected by the gas in the path CA and the heat absorbed by the gas in the path AB; (c) the net heat absorbed by the gas in the path BC; (d) the maximum temperature attained by the gas during the cycle. 60. One mole of a diatomic ideal gas (g = 1.4) is taken through a cyclic process starting from point A. The process A ® B is an adiabatic compression, B ® C is isobaric expansion, C ® D is an adiabatic expansion, and D ® A is isochoric. The volume ratios are VA / VB = 16 and VC / VB = 2 and the temperature at A is TA = 300 K.Calculate the temperature of the gas at the points B and D and find the efficiency of the cycle. [1997 - 5 Marks] 61. At 27°C two moles of an ideal monoatomic gas occupy a volume V. The gas expands adiabaticallly to a volume 2V. Calculate (i) the final temperature of the gas, (ii) change in its internal energy, and (iii) the work done by the gas during this process. [1996 - 5 Marks] 62. One mole of a mono atomic ideal gas is taken through the cycle shown in Fig: [1993 - 4+4+2 Marks] A ® B : adiabatic expansion

P

A B

B ® C : cooling at constant volume C ® D : adiabatic compression D

C

D ® A : heating at constant volume. V The pressure and temperature at A, B, etc. are denoted by

PA , TA , PB , TB etc., respectively. Given that TA = 1000 K,

58.

(a) the work done on the gas in the process AB and (b) the heat absorbed or released by the gas in each of the processes. Give answer in terms of the gas constant R. Two moles of an ideal monatomic gas, initially at pressure p1 and volume V1, undergo an adiabatic compression until its volume is V2. Then the gas is given heat Q at constant volume V2. [1999 - 10 Marks]

PB= (2/3)PA and PC = (1/ 3) PA , calculate the following quantities: (i) The work done by the gas in the process A ® B (ii) The heat lost by the gas in the process B ® C. (iii) Thetemperature TD. [Given : (2 / 3)2/5 = 0.85] 63. Two moles of helium gas undergo a cyclic process as shown in Fig. Assuming the gas to be ideal, calculate the following quantities in this process [1992 - 8 Marks]

WWW.JEEBOOKS.IN

EBD_8341 P-116

Physics

鼀

҈鼀









⧤

⧤

㡰  ᆠ  ��    �泐 㡰  犨ᨨ├ ᨨ  ᆠ㡰  ᆠ  �� �   �泐 

鼀ᨨ矄ᨨ  � �矄 æç C p = 䰘 Rö÷ 矄矄盐 PA è  ø  鼀盐 TA �矄�矄ᨨ 鼀泐   ᨨ犨�ᆠ�矄 � ��ᨨ盐鼀ᔼ�矄  ᆠᨨ鼀矄矄 ᆠᨨ 矄 矄矄盐ᨨ �矄ᨨ��� ᨨ盐鼀 � 泐�矄�矄ᆠᨨ鼀矄矄 ᆠᨨ 矄  ᨨ盐鼀ᨨ�矄ᨨ��� 矄矄盐PA ᲼҈黨黨҈㜠졔㝐├矄桌 㡰 和├ᆠ P 㜠 V   P㜠 T ��鼀矄 ᨨ  ᆠᨨ鼀 ᨨᆠ矄矄 㡰 ᔴᆠ盐  犨ᨨ├ ᨨ 泐 �矄    矄盐� ᨨ �矄 盐� � ᆠᨨ鼀ᨨᆠ矄矄

� 꾀  �  �矄 � � � �� 矄矄盐 P ᨨ盐鼀 V  鼀盐T�矄ᨨ犨 ᨨ   ��ᆠ泐盐 ��矄 T ᨨ盐鼀ᆠᨨ鼀矄�V犨 ��矄鼀盐 矄ᨨ   ᲼҈黨黨㜠䰘㝐├桌 �㡰 ᨨ犨鼀 泐 �矄ᨨ   ᨨ鼀 ᨨ �矄鼀ᨨᆠ盐矄 䁸 ��㡰 졠�  犨ᨨ├ ᨨ 泐 �矄 盐� �   矄�ᨨ

矄 盐 ᆠ�ᨨ ᨨ  � ��矄矄盐P ᨨ盐鼀V  꾀  �  �矄 矄  矄ᆠ� �ᆠ   ᆠᨨ 矄  矄矄盐 �R  �矄�矄├� ᆠᨨ矄 矄矄ᨨ ᨨ盐鼀 CP =   鼀 鼀盐ᨨ ⧤ 矄矄盐ᨨ ҈맔 ҈⏌鼀꾀 鼀ᨨ盐 ᨨ 黨맔҈ᨨ盐矄ᨨ   �泐 �矄矄盐� ᨨ �矄ᔴᆠ盐  � 鼀盐 矄矄盐ᨨ  �矄 ᲼҈黨䰘㜠䰘㝐├桌 䰘 ᔴᆠ盐 犨ᨨ├ ᨨ 犨  ᨨ 鼀ᨨᨨ  ᆠ�矄�矄 ᆠᨨ鼀矄矄  ��ᆠ泐 � ��矄矄盐 ᨨ盐鼀 ᨨ  �矄҈�⏌鼀 �矄矄ᆠ�泐  �  ᨨ盐鼀ᨨ  �矄�矄�㝐ᨨ矄ᆠ� �ᆠ ᨨ  �矄 ᆠᨨ 矄 ᨨ盐鼀�矄 ⏌ ᲼҈黨㜠㝐├矄桌

Topic-3 : Carnot Engine, Refrigerators and Second Law of Thermodynamics 1 ҈

MCQs with One Correct Answer



꾀  �� ᨨ矄泐├� �鼀ᨨ ᨨ鼀�ᆠ� �矄  ᨨ盐�   ᆠ泐ᆠ矄 ᨨ犨  �    ��盐 ᆠ �  �ᆠ� ᆠ泐ᨨ   �� �矄ᆠᨨ矄ᨨ ᲼㝐� 和 ᔼᔼ㡰桌   졠



ᔴ

犨ᨨ� ᔴ ᨨ �� 矄ᨨ� ᆠ矄ᆠ    �� 盐泐ᨨ  �� �矄盐矄 泐 ᨨ  �� ᨨ ᨨ 盐ᆠ犨ᨨ├㡰犨 鼀盐矄 T҈ T  鼀盐ᨨ   ᨨ矄ᨨ�ᨨ   �矄 �� �矄T҈   鼀盐ᨨ  ᆠᨨ 矄ᨨ�ᨨ  矄ᆠᨨ  �� �矄T �矄鼀盐ᨨ  矄� ├ᨨ  �矄 ��  犨 �ᆠ �矄矄ᨨ 矄ᨨ盐ᆠ ᨨ 矄ᆠᨨ  �� ᨨ犨�矄 T ᨨT҈ T� ᨨ   �� 矄 ᨨ鼀⼄盐 鼀ᨨ盐 ᨨ 犨ᨨ├䁸 ᲼㝐� 䰘 ᔼᔼ桌

졠 졠

꾀 졠





 졠

㡰 ҈黨 㡰 ҈ ᆠ㡰  㡰  꾀  �� �矄� ᨨ 犨�  ᆠ  �ᨨ  ᨨ ҈黨҈� 졔҈�  Q 盐� �ᨨ ᆠ泐ᆠᆠ �� �

 �ᆠ� ᆠ泐ᨨ �奠 盐ᨨ Q�矄 [Main 2 Sep. 2020 (II)] 㡰  㡰  ᆠ㡰 黨 㡰  ҈ 꾀ᔴ ᨨ ��  � �  �ᆠ� ᆠ泐ᨨ  �矄� �盐矄 ҈ 矄 ��ᨨᔼ  犨ᨨ├ ᨨ ᨨ   ��ᨨ�矄҈  鼀ᨨ盐 ᨨ  矄ᨨ  ᨨ鼀 矄ᨨ�ᨨ犨 鼀盐�矄 ᲼㝐�  ᔼᔼ桌 㡰 黨黨 㡰 ҈ ᆠ㡰 ҈ 㡰 黨

�



T҈T T҈ + T

㡰

T=

ᆠ㡰

T = T҈T

㡰 T =

T҈ + T 

㡰 T㦨

꾀 ᔴ ᨨ  ��  矄    �ᆠ� ᆠ泐 ᨨ  ҈⏌ ␔     鼀盐ᨨ  矄� ├�矄 盐ᆠ 泐ᨨᔴ�矄 �ᆠ� ᆠ泐 �矄 ᨨ盐  鼀盐矄ᨨ  矄ᨨ盐ᆠ  矄� ├ 矄ᆠ�泐 ᲼㝐� ҈꾀҈黨ᔼᔼ桌 㡰 ᨨᔴ҈ᨨᔴ 㡰 黨黨ᨨᔴ䰘ᨨᔴ ᆠ㡰 ҈ᨨᔴᨨᔴ 㡰 䰘ᨨᔴ黨黨ᨨᔴ

ᔴ ᨨ  �� 矄ᨨ�  矄�矄犨    矄ᨨ盐ᆠ   鼀盐 ҈     矄� ├  鼀盐  矄 ��盐㡰   犨ᨨ ᨨ  矄ᨨ�矄鼀盐   矄矄 ᨨ犨 犨�  ҈ > > > 㡰   �� 矄⼄盐泐 �ᆠ�  �  ᲼㝐� ҈ ҈黨ᔼ桌

WWW.JEEBOOKS.IN

P-117

Thermodynamics

A solid body of constant heat capacity 1 J/°C is being heated by keeping it in contact with reservoirs in two ways: [Main 2015] (i) Sequentially keeping in contact with 2 reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with 8 reservoirs such that each reservoir supplies same amount of heat. In both the cases body is brought from initial temperature 100°C to final temperature 200°C. Entropy change of the body in the two cases respectively is : (a) ln2, 2ln2 (b) 2ln2, 8ln2 (c) ln2, 4ln2 (d) ln2, ln2 12. A Carnot engine absorbs 1000 J of heat energy from a reservoir at 127°C and rejects 600 J of heat energy during each cycle. The efficiency of engine and temperature of sink will be: [Main Online April 12, 2014] (a) 20奠 and – 43°C (b) 40奠 and – 33°C (c) 50奠 and – 20°C (d) 70奠 and – 10°C 13. p A B 2p 11.

7.

8.

9.

(a)

T2 = ( T1 T4 )

(b)

T2 = T12 T4

(

)

1/3

(c)

T2 = T1 T42

(

)

1/3

(d)

T2 = T13 T4

(

)

1/2

1/4

(

)

; T3 = T1 T42

(

)

; T3 = T12 T4

(

)

(

)

; T3 = T12 T4

; T3 = T1 T43

1/3

1/3

1/3

1/4

Two Carnot engines A and B are operated in series. The first one, A receives heat at T1 (= 600 K) and rejects to a reservoir at temperature T2. The second engine B receives heat rejected by the first engine and in turn, rejects to a heat reservoir at T3 (= 400 K). Calculate the temperature T2 if the work outputs of the two engines are equal: [Main 9 Jan. 2019 II] (a) 600 K (b) 400 K (c) 300 K (d) 500 K A Carnot's engine works as a refrigerator between 250 K and 300 K. It receives 500 cal heat from the reservoir at the lower temperature.The amount of work done in each cycle to operate the refrigerator is: [Main Online April 15, 2018] (a) 420 J (b) 2100 J (c) 772 J (d) 2520 J An engine operates by taking n moles of an ideal gas through the cycle ABCDA shown in figure. The thermal efficiency of the engine is : (Take Cv =1.5 R, where R is gas constant) [Main Online April 8, 2017] (a) 0.24 (b) 0.15

2P0

(d) 0.08

C

B

P P0

(c) 0.32

10.

0

D

A

V0

2V0

V

A Carnot freezer takes heat from water at 0°C inside it and rejects it to the room at a temperature of 27°C. The latent heat of ice is 336 × 103 J kg–1. If 5 kg of water at 0°C is converted into ice at 0°C by the freezer, then the energy consumed by the freezer is close to : [Main Online April 10, 2016] (a) 1.51 × 105 J (b) 1.68 × 106 J 7 (c) 1.71 × 10 J (d) 1.67 × 105 J

p0

D

C

v0 2v0 v The above p-v diagramrepresents the thermodynamic cycle of an engine, operating with an ideal monatomic gas. The amount of heat, extracted from the source in a single cycle is [Main 2013] æ 13 ö (a) p 0 v 0 (b) ç ÷ p0 v0 è2ø æ 11 ö (c) ç ÷ p0 v0 (d) 4p0v0 è2ø 14. Two identical containers A and B with frictionless pistons contain the same ideal gas at the same temperature and the same volume V. The mass of the gas in A is mA, and that in B is mB. The gas in each cylinder is now allowed to expand isothermally to the same final volume 2V. The changes in the pressure in A and B are found to be DP and 1.5 DP respectively. Then [1998S - 2 Marks] (a) 4mA = 9mB (b) 2mA = 3mB (c) 3mA = 2mB (d) 9mA = 4mB 3

Numeric Answer

15. If minimum possible work is done by a refrigerator in converting 100 grams of water at 0°C to ice, how much heat (in calories) is released to the surroundings at temperature 27°C (Latent heat of ice = 80 Cal/gram) to the nearest integer? [Main 3 Sep. 2020 (II)] 16. A Carnot engine operates between two reservoirs of temperatures 900 K and 300 K. The engine performs 1200 J of work per cycle. The heat energy (in J) delivered by the engine to the low temperature reservoir, in a cycle, is _______. [Main 7 Jan. 2020 I]

WWW.JEEBOOKS.IN

EBD_8341 P-118

Physics

8

犨 �ᆠ  矄泐� ⼄盐���盐鼀ᔼ   �矄ᆠᨨ ��ᨨ   ᲼䰘桌 �矄 ᆠᨨ  �矄ᨨ  ᨨ鼀 ᨨ�矄

Comprehension/Passage Based Questions

矄矄� 꾀 �   鼀泐ᆠᨨ 盐ᆠ� �ᆠ泐�  矄 �盐矄   ��   ᆠ泐� �矄ᨨ �矄ᨨᨨ鼀  矄矄鼀 ᨨ�矄 ᨨ꾀�矄ᨨ ᨨ 鼀矄矄㝐�矄   �矄 ᆠ ᨨ鼀 ᨨ 矄盐 ᆠ矄矄 ᨨ犨 �   ��盐 鼀ᨨ矄 �ᆠ矄矄盐�矄 

㡰

æ    ö÷ çç  ÷ 㡰 ÷ çç  ÷ ÷  졔  㝐� è ø 

æ   㜠 㝐� ÷ ö ÷ 㡰 ççç  ÷ ÷ 㡰 çè    ÷ ø

ᆠ㡰

 æ ö çç   졔 㝐� ÷ ÷ 㡰 ÷ ç ÷ ÷ çè    ø

æ    ö÷  ÷ 㡰 㡰 ççç ÷ ÷ çè    㜠 㝐� ÷ ø







�矄ᨨ

�矄ᨨ �矄 ᨨ犨盐 ᨨ盐矄ᨨ犨泐    �矄 ᆠ  ᨨ鼀 ᨨ 矄矄盐�  ᆠ泐� 犨 �矄 ᨨ  �矄ᨨ 犨�   ᲼䰘桌

҈䰘

㡰 

㡰

҈黨 �矄ᨨ �矄├ ᆠᨨ鼀泐ᨨ盐ᨨ  ᆠ泐�   ᨨ ᨨ�矄矄 꾀犨 ├�矄ᨨ盐� ᨨ犨  ᆠ泐�  盐� ᨨ矄��ᨨ 矄ᨨ  犨矄盐 ᆠ�

  ├�矄 矄鼀矄 ᨨᨨ  ᆠ泐� 矄 矄 ᨨ犨  �    ��盐   矄�泐ᨨ    犨 �矄 r ᔼ

⼄盐���盐鼀  �� ᨨ  犨ᆠᨨ盐鼀 �  ᆠ泐�  矄�矄 �矄 ᲼䰘桌

 



 㝐�  㝐� 㜠 졔 㡰      

 ᨨ 矄矄盐� 矄�  ᆠ泐� �矄 ᨨ盐� ᨨ盐  矄ᨨ犨盐� �ᨨᆠ矄矄 ␔ � �矄ᨨ �矄 �矄 ᆠ ᨨ鼀 ᨨ  ᨨ  ᨨ�矄矄  �矄ᨨ �矄  矄 ᨨᨨ矄��ᨨ



ᆠ㡰

҈

㡰 㡰 ᆠ㡰 㡰

r� 㡰졔 㡰졔㦨 r� 㡰 㡰㦨 r� 㡰졔 㡰㦨 r� 㡰 㡰졔㦨

Answer Key Topic-1 : First Law of Thermodynamics ҈ 㡰  㡰  㡰 黨 꾀㜠錐㜠錐ᔴ㜠⼄矄錐㜠

 㡰

� 㡰

 ᔴᨨ 矄 㡰 䰘 ᆠ㡰 

ᆠ㡰

Topic-2 : Specific Heat Capacity and Thermodynamical Processes ҈ ҈҈ ҈ ҈  黨

㡰 㡰 㡰 㡰 㡰 ᆠ㡰

 ҈   ҈ �

ᆠ㡰 㡰 㡰 㡰 盐㡰 ᆠ㡰

 ҈    �҈

㡰 㡰 㡰 㡰  㡰 㡰

 ҈    �

㡰 㡰 ᆠ㡰 㡰 ᆠ㡰 㡰

� ҈� � �  �

㡰 㡰 㡰 㡰 㡰 㡰

 ҈   � �

ᨨ 盐矄㡰 䰘 㡰 ҈䰘 㡰 䰘 㡰 䰘  㡰  㡰

㡰  ᆠ㡰 ҈ 㡰  ҈҈㡰  ᆠ 㡰

ᆠ㡰 黨 㡰 ҈ 㡰 ҈黨 ᆠ㡰  㡰 黨 㡰  ҈䰘㡰 黨 �㡰 䰘 㡰 

ᆠ㡰 㡰 㡰 㡰

Topic-3 : Carnot Engine, Refrigerators and Second Law of Thermodynamics ҈ 㡰 ҈҈ 㡰

 ᆠ㡰 ҈ 㡰

 㡰 ҈ 㡰

 㡰 ҈ ᆠ㡰

� 㡰  㡰 䰘 㡰 ҈� 䰘黨҈㡰 ҈ 㡰 ҈䰘 㡰

 㡰 ҈ 㡰

黨 㡰 ҈黨 ᆠ㡰

҈ 㡰

WWW.JEEBOOKS.IN

P-119

Kinetic Theory

Kinetic Theory

12

Topic-1 : Kinetic Theory of an Ideal Gas and Gas Laws 1 ҈

ᨨ盐ᨨ   ᨨᨨ犨� �犨 �ᆠ ᨨ ᆠᨨᆠ泐矄 矄  㜠  ��鼀䁸 ᲼㝐� 졠 � 꾀�黨҈䰘桌  

㡰

㡰

MCQs with One Correct Answer

꾀�ᆠᆠᨨ矄 ᆠ泐� �矄矄 � ᨨ犨ᨨ矄泐 �ᆠ�ᨨ 矄矄�矄ᨨ ᨨ 鼀矄矄鼀 ᨨ  ���� �ᆠ├ 矄矄

�矄ᨨ �矄 ᨨ鼀ᨨᨨ �  � ᨨ  ᆠ泐� 

 � ᨨ  ᆠ泐� ᨨ �矄ᨨ �矄l҈   ᨨ犨 �矄ᨨ �矄l矄盐ᆠ  l҈>l쟼ᆠ ᨨ   ᆠ泐� ᆠᨨ � 矄 鼀ᨨ矄ᨨ  � �矄⼄盐鼀盐

ᔼ  �矄ᨨ �矄矄�ᨨ 泐�矄鼀矄矄鼀犨��� 泐 �矄盐 �矄�矄ᆠᨨ 矄  ��矄 ᆠᆠ�ᨨ  盐ᨨ ��泐㡰 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰

é l҈ - l ù ê ú

� ë l҈ I  û

㡰

҈



҈  㦨









�



҈

҈

ᆠ㡰

ᆠ㡰







é l҈ + l ù ê ú � ë l҈ I  û

é l҈ - l ù

é ҈ ҈ ù ê ú 㡰 ê + ú � ë l҈ l û � ë l l҈ û

鼀盐ᨨ  ᨨ ᨨᨨ鼀ᨨ ᨨ盐鼀鼀� ᆠ矄矄 ᨨ鼀҈䰘 ᔴᨨ䰘 ᔴ 盐ᨨ矄盐 矄 �  鼀ᨨ矄 �ᆠ矄矄盐 �  ᨨᨨ鼀鼀� 矄҈맔҈�ᔼ  �    盐鼀ᨨ 鼀ᨨᆠ盐矄�  ᨨᨨ鼀 ᨨ   � �    � 犨� ᲼҈䰘桌 㡰 �맔҈� 㡰 �맔҈� ᆠ㡰 ҈҈맔҈ 㡰 ҈맔҈ ᨨ 㜠 ��鼀��  ᨨ � �矄

҈





 

犨ᨨ ᨨ 㜠ᆠ�鼀ᨨ ᨨᨨ鼀�ᆠ� �矄矄  �ᨨ鼀�ᆠ 鼀矄矄矄�  �ᨨ �ᨨᨨ  ��矄矄盐矄 犨   ᆠᨨ矄 � 矄矄├ᆠᨨ 矄 鼀盐 �矄 �ᨨᨨ  �  矄��矄�矄 ᲼꾀 ҈桌 㡰 ҈ 㡰 ҈ ᆠ㡰 黨 㡰 黨 꾀�矄 矄�├ � �矄� �矄 ᲼҈桌 㡰 矄矄盐 鼀盐ᨨ  �� 㡰 矄矄盐 鼀盐ᨨ ᨨ犨 ᆠ㡰 矄矄盐�矄 ��  鼀盐�矄ᨨ犨 㡰 矄矄盐�矄ᨨ犨 鼀盐�矄 �� ␔ �ᆠ ᨨ   ᨨᨨ犨� �� 矄ᆠᨨᆠ泐矄 矄  dV ⏌ dP  犨� P ᨨ  �  �矄  V ᆠᨨ 矄 鼀盐䁸 ᲼和桌

��ᨨ  ᨨ  b = -

ᔴᨨ 矄  

㡰

㡰  

P

P

WWW.JEEBOOKS.IN

EBD_8341 P-120

Physics

3 ᆠ㡰

䰘



Numeric Answer

ᔼ ��泐 �矄 ᨨ  �ᨨ鼀�ᆠ鼀ᨨᆠ盐矄�矄 ᆠᨨ �   �   ᆠ泐� ᨨ ᨨ盐鼀҈矄矄盐҈ 鼀盐 �⧤꾀矄矄盐鼀� � �奠ᨨ  鼀ᨨᆠ盐矄� �矄矄ᨨᆠ� ᆠ盐矄� �ᆠ  ��  盐鼀ᨨ 鼀ᨨ矄 矄矄盐ᨨ   矄盐� ��矄鼀盐⧤犨  ᆠᨨ �  �  ᨨ盐鼀҈�矄�� 泐 �ᨨ⏌҈�矄힘힘힘힘힘힘 ᲼㝐� 和 ᔼ㡰桌 ҈ ᆠ  ��  鼀� �盐 ᨨ  ᨨ盐鼀ᨨ  � �矄 犨    矄鼀  ��ᨨ  矄矄盐 DP �矄 �    ᆠᨨ 矄 鼀盐�矄 矄鼀矄 ᆠ  �犨    鼀盐�矄 盐ᆠ 泐矄鼀⼄盐 �泐DT ᆠᨨ 矄  矄矄盐 � ��鼀盐 矄矄盐ᨨ  �矄 黨



P P

犨ᨨ�  �ᆠᆠᨨ � 矄꾀 犨�  �ᆠ�ᨨ 矄矄�矄ᨨ 矄 ᆠᨨ �  矄鼀� �矄 矄鼀鼀盐  矄鼀ᨨ盐鼀 鼀矄矄ᨨ  �矄� 꾀�矄鼀꾀  � �矄鼀 �矄� ᆠ ᆠ泐� �矄 ᨨ犨ᨨ犨 ᨨ   �矄ᨨ 鼀泐ᨨ 矄鼀 � ᨨ盐鼀  ᆠ  �矄�  矄矄盐� 꾀  ᨨ盐 ᨨD ҈�D矄ᆠ�泐 

᲼҈黨黨和㜠㝐├矄桌 㡰 鼀꾀㦨黨鼀 㡰 鼀꾀㦨鼀 ᆠ㡰 鼀꾀㦨鼀 㡰 黨鼀꾀㦨鼀

2 Integer Value Answer 꾀 鼀泐�矄ᨨ ᆠ泐� �ᆠᆠᨨ矄 矄矄ᨨ  �� 鼀 �矄├�ᆠ泐ᔼ�矄 ��  � ᨨ犨ᨨ⼄盐矄泐 � 鼀�ᆠ  ᆠ 鼀ᆠᨨ 盐ᆠᨨ㡰 �ᆠ�ᨨ 矄矄��ᨨ

ᨨ 鼀矄矄├� 盐矄 ��ᨨ �矄  � ��泐 �矄 ᆠ ᨨ 鼀 ᨨ鼀 ᨨ矄矄 ᨨ犨 �  矄ᆠ 鼀�ᆠ ��盐ᨨ犨 쟼ᆠ ᨨ  犨ᨨ矄ᨨ  矄矄ᆠᨨ � 矄҈鼀ᨨᨨ 

� �矄鼀盐⧤ ��ᨨ �矄 ᨨ犨矄  鼀ᨨ矄犨� ᨨ盐 泐�矄├� � ᨨ鼀ᨨ ᨨ   矄矄 ᨨ   ᨨ  ␔   ⼄盐���盐鼀 �矄 ᆠ     �矄 ᆠᨨ  ��ᨨ  ᨨ鼀 ᨨ � 鼀㡰犨�힘힘힘힘힘힘힘 ├   ᆠᆠ�ᨨ  盐 ᨨ ��泐㦨҈ 鼀矄     盐 �矄�矄ᆠᨨ 矄 㦨鼀ᨨ҈⧤҈㡰

犨⧤ 鼀矄ᆠ�泐ᔼ   DT = C  DP   

盐ᨨ C�  ⧤⏌鼀㡰�矄힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌 4

Fill in the Blanks

҈҈ 盐� �  �鼀  � �矄�矄 ᨨ盐 ᨨᨨ泐

 ��ᨨ  犨VP 㦨ᆠᨨ 矄  �矄�矄� ��泐  鼀盐T ᨨ盐鼀V␔  �  矄ᨨᨨ盐鼀 V 鼀盐ᆠᨨ鼀矄 ᲼҈黨䰘㜠㝐├矄桌 5

True / False

҈ ᨨ盐鼀V矄盐矄鼀盐T� 矄 ᨨᆠ�

鼀ᨨ盐 ᨨ  ᆠ�矄犨ᨨ矄矄盐p҈ p矄 矄 ᨨ犨 �  ��ᔼ ᨨᨨ犨矄 ᨨ鼀 � 矄 p҈�矄�   p ᲼҈黨㜠㝐├矄桌 p҈ V

鼀

p

T

Topic-2 : Speed of Gas, Pressure and Kinetic Energy 1 ҈



MCQs with One Correct Answer

盐鼀ᨨ 鼀ᨨᆠ盐矄� ᨨ盐鼀ᨨ ᆠ鼀 ᨨ  ᆠ 鼀ᨨ ᨨᨨ鼀�ᆠ�矄矄ᨨ鼀鼀盐T 矄矄盐 ᨨ ᆠ鼀ᨨ 鼀ᆠ盐泐�矄ᆠᨨ矄ᨨ䁸 ෌� 鼀 ├� �ᆠ �泐 ᨨ 鼀ᨨᆠ盐 T㡰�矄맔҈҈�g㦨黨ᆠ鼀⏌矄  矄�泐 ᨨ 鼀ᆠ盐泐㦨҈�⏌ᆠ鼀㡰 ᲼㝐� 和� ᔼ㡰桌 㡰 맔҈҈ 㡰 맔҈҈ ᆠ㡰 �맔҈҈ 㡰 �맔҈҈ ᨨ  ��  �矄  ҈ 鼀 矄矄盐 鼀矄 矄  ᨨ    鼀ᨨᆠ盐矄�矄鼀⏌矄҈䰘 ᔴ꾀鼀矄矄盐  䰘 ᔴ 鼀矄矄 ᨨ  鼀ᨨᆠ盐矄犨� ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰 ҈鼀⏌矄 㡰  � 鼀⏌矄 ᆠ㡰 ҈ � 鼀⏌矄

㡰 鼀⏌矄





ᔼ ҈�矄鼀ᨨᆠ盐矄ᆠ ᨨ 鼀矄矄҈├�ᆠᨨ� 犨�  矄盐 ᆠ  �ᆠ盐ᨨ�㡰矄�ᆠ泐矄ᆠᨨ ᨨ  ҈鼀犨� 矄 ҈鼀⏌矄 矄矄盐  泐  �矄鼀ᨨᆠ盐矄犨�ᨨ  ᨨ ᨨ  ᲼㝐� 꾀�҈黨ᔼ桌 㡰 ҈⏌鼀 㡰 ҈⏌鼀 ᆠ㡰 ҈⏌鼀 㡰 ҈҈⏌鼀

鼀盐犨 �ᆠ  ᨨᨨ鼀 矄⼄盐ᨨᆠ�泐 ᨨ  泐 ᨨ� 鼀ᨨᆠ盐矄⼄盐矄 �矄ᆠᨨᆠ�泐 ᨨ鼀   �矄ᆠᨨ矄矄ᨨ ᲼㝐� 꾀�҈黨ᔼᔼ桌 ᲼ᨨ 鼀

ᔴᨨ 矄 k㦨҈맔҈⏌⧤ 꾀ᨨ� ᨨ盐鼀꾀㦨맔҈⏌├�  �盐矄ᨨ 쟼 맔҈鼀 ෌��ᨨ ᆠᆠ�ᨨ ᨨ 쟼 㦨҈鼀矄桌

WWW.JEEBOOKS.IN

P-121

Kinetic Theory

5.

(a) 800 K (b) 3 × 105 K (c) 104 K (d) 650 K A mixture of 2 moles of helium gas (atomic mass = 4u), and 1 mole of argon gas (atomic mass = 40u) is kept at 300 K in a container. The ratio of their rms speeds

6.

é Vrms ( helium ) ù ê ú is close to : [Main 9 Jan. 2019 I] ë Vrms ( argon ) û (a) 3.16 (b) 0.32 (c) 0.45 (d) 2.24 N moles of a diatomic gas in a cylinder are at a temperature T. Heat is supplied to the cylinder such that the temperature remains constant but n moles of the diatomic gas get converted into monoatomic gas. What is the change in the total kinetic energy of the gas? [Main Online April 9, 2017] 1 nRT (b) 0 2 3 5 nRT nRT (d) (c) 2 2 In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on T as Tq. A good estimate for q is: [Main Online April 10, 2015] 1 1 (a) (b) 2 (c) 1 (d) 2 4 At room temperature a diatomic gas is found to have an r.m.s. speed of 1930 ms–1. The gas is: [Main Online April 12, 2014] (a) H2 (b) Cl2 (c) O2 (d) F2 In the isothermal expansion of 10g of gas from volume V to 2V the work done by the gas is 575J. What is the root mean square speed of the molecules of the gas at that temperature? [Main Online April 25, 2013] (a) 398m/s (b) 520m/s (c) 499m/s (d) 532m/s A mixture of 2 moles of helium gas (atomic mass = 4 amu) and 1 mole of argon gas (atomic mass = 40 amu) is kept at 300 K in a container. The ratio of the rms speeds æ vrms (helium) ö [2012] çè v (argon) ÷ø is rms (a) 0.32 (b) 0.45 (c) 2.24 (d) 3.16 The ratio of the speed of sound in nitrogen gas to that in helium gas, at 300 K is [1999S - 2 Marks]

(a)

7.

8.

9.

10.

11.

(a) 12.

13.

(2 / 7

(b)

(1 / 7)

(c) ( 3 ) / 5 (d) ( 6 ) / 5 A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is [1999S - 2 Marks] (a) same everywhere (b) lower in the front side (c) lower in the rear side (d) lower in the upper side A vessel contains 1 mole of O2 gas (relative molar mass 32) at a temperature T. The pressure of the gas is P. An identical

vessel containing one mole of He gas (relative molar mass 4) at a temperature 2T has a pressure of [1997 - 1 Mark] (a) P/8 (b) P (c) 2P (d) 8P 14. The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K the root-mean-square velocity of the gas molecules is v, at 480 K it becomes [1996 - 2 Marks] (a) 4v (b) 2v (c) v/2 (d) v/4 15. Three closed vessels A, B and C are at the same temperature T and contain gases which obey the Maxwellian distribution of velocities. Vessel A contain only O2, B only N2 and C a mixture of equal quantities of O2 and N2. If the average speed of the O2 molecules in vessel A is v1 that of the N2 molecules in vessel B is v2, the average speed of the O2 molecules in vessel C is [1992 - 2 Marks] 1

v1 + v2 (b) v1 (c) (v1.v2 ) 2 (d) 2 where M is the mass of an oxygen molecule.

(a)

3

3kT M

Numeric Answer

16. Nitrogen gas is at 300°C temperature. The temperature (in K) at which the rms speed of a H2 molecule would be equal to the rms speed of a nitrogen molecule, is _____________. (Molar mass of N2 gas 28 g); [Main Sep. 05, 2020 (II)] 5

True / False

17. The root mean square (rms) speed of oxygen molecules (O2) at a certain temperature T (degree absolute) is V. If the temperature is doubled and oxygen gas dissociates into atomic oxygen, the rms speed remains unchanged. [1987 - 2 Marks] 18. The ratio of the velocity of sound in Hydrogen gas 7 5 ( g = ) to that in Helium gas ( g = ) at the same 5 3 21 temperature is . [1983 - 2 Marks] 5 19. Two different gases at the same temperature have equal root mean square velocities. [1982 - 2 Marks] 20. The root-mean square speeds of the molecules of different ideal gases, maintained at the same temperature are the same. [1981- 2 Marks] 6

MCQs with One or More than One Correct Answer

21. Let v, v rms and vp respectively denote the mean speed. root mean square speed, and most probable speed of the molecules in an ideal monatomic gas at absolute temperature T. The mass of a molecule is m. Then [1998S - 2 Marks] (a) no molecule can have a speed greater than

2 v rms

(b) no molecule can have a speed less than v p / 2 (c) v p < v < v rms 3 2 (d) the average kinetic energy of a molecule is mv p . 4

WWW.JEEBOOKS.IN

EBD_8341 P-122

Physics

Topic-3 : Degree of Freedom, Specific Heat Capacity and Mean Free Path 1 ҈

㝐ᨨᆠ盐矄 ᨨ    �  �矄  ├ ᨨ犨  ᨨ     矄�ᨨ  �矄ᨨ   ᨨ鼀 犨ᨨᨨ�ᨨ  �矄 ᨨ   ᨨ鼀 �矄�矄鼀� �  鼀盐ᨨ  

ᨨ�   �泐ᨨ 鼀ᨨᨨ  �矄�矄   æ Cp ö 盐ᨨ  g ç = ÷ �� 矄ᆠ�泐泐 è Cv ø ᲼㝐� 和 ᔼ㡰桌 �  㡰 㦨  g㦨  �





�

䰘 �

� 䰘  ᆠ㡰 㦨  g㦨 㡰 㦨�  g㦨  � � ᔼ  �盐�矄矄矄盐P 鼀盐T 鼀

�鼀 犨  矄盐ᆠᆠ矄矄�ᆠᨨ�矄�ᨨ 矄 ᨨ  鼀ᨨᆠ盐 �矄 犨� T�矄 ᲼㝐� 和 ᔼᔼ㡰桌

҈

҈ ᆠ㡰 㡰 T T T 㝐ᆠ  ᔴ⏌ᔴ�ᨨ ᨨ� �矄矄犨�  �  泐 ᨨ 鼀ᨨᆠ盐矄 ᲼㝐� 和 ᔼ㡰桌 ᔴᨨ盐鼀 㜠ᔼ ᔴᨨ盐鼀 㜠ᔼᔼ 㝐ᨨᆠ盐Ty ᔴ⏌ᔴ 꾀㡰 㝐ᨨ ᨨ鼀�ᆠ ᔼ㡰䰘⏌� 㡰 �ᨨ鼀�ᆠ��� 鼀ᨨᆠ盐矄 ᔼᔼ㡰黨⏌䰘 ᔴ㡰 �ᨨ鼀�ᆠ ᨨ 㜠��� 鼀ᨨᆠ盐矄 ᔼᔼᔼ㡰⏌ 㡰 �ᨨ鼀�ᆠ��� 鼀ᨨᆠ盐矄 ᔼ㡰�⏌ 㡰 꾀㡰㜠 ᔼ㡰 㡰㜠 ᔼᔼ㡰 ᔴ㡰㜠 ᔼ㡰 㡰㜠 ᔼᔼᔼ㡰 㡰 꾀㡰㜠 ᔼᔼᔼ㡰 㡰㜠 ᔼ㡰 ᔴ㡰㜠 ᔼᔼ㡰 㡰㜠 ᔼ㡰 ᆠ㡰 꾀㡰㜠 ᔼ㡰 㡰㜠 ᔼ㡰 ᔴ㡰㜠 ᔼᔼ㡰 㡰㜠 ᔼᔼᔼ㡰 㡰 꾀㡰㜠 ᔼᔼ㡰 㡰㜠 ᔼᔼᔼ㡰 ᔴ㡰㜠 ᔼ㡰 㡰㜠 ᔼ㡰 ᔴᨨ 矄� �矄ᨨ �ᨨ鼀�ᆠ鼀ᨨᆠ盐矄

 鼀ᨨᆠ盐矄  矄矄盐鼀  ᨨ  � �盐 鼀 ᨨ 鼀矄矄矄矄��� ᨨ 矄 犨 ᨨ矄 �ᆠ矄  ᨨᆠᆠ盐�  泐 ᨨ鼀矄 �   �泐ᨨ 鼀ᨨᨨ  �矄鼀盐T�矄 ᲼㝐� 和 ᔼ㡰桌

㡰 T 

㡰 㦨�  g㦨

㡰

꾀�矄鼀� 盐ᆠᨨ 矄�矄矄ᨨ 鼀ᨨ矄ᨨ ᨨ 泐�  �鼀ᨨ矄ᨨ �ᨨ 鼀盐T꾀矄矄盐鼀� � �矄矄ᨨ�    ᨨ 泐� ᨨ ᨨ���  ᨨ�   �泐 � 盐 �矄ᨨ  㡰ᨨ  鼀� 盐�矄 ᲼㝐� 和 ᔼ㡰桌 㡰 ҈� 㡰 ҈ ᆠ㡰  㡰 ҈҈ 䰘 꾀 � �矄� ᆠᨨ矄 ᆠᨨ � �矄矄ᨨ犨泐  꾀矄�矄 鼀盐� ᆠ矄矄犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄 盐䁸 ᲼㝐� 和 ᔼᔼ㡰桌 ҈㡰 鼀   ᨨ  鼀ᨨᆠ盐矄 ᆠ矄矄 㡰  鼀  ᆠᨨ�矄�ᨨ  �鼀 犨    鼀ᨨᆠ盐矄 ᆠ矄矄 㡰 鼀   鼀� 矄盐 ᆠ  � 㡰 鼀 ᆠᨨ�矄�ᨨ �鼀鼀� 矄盐 ᆠ  � 㡰 㡰  㡰 㡰 ҈㡰  㡰 ᆠ㡰 㡰  㡰 㡰 ҈㡰  㡰  ᔴᨨ 矄�  犨ᨨ�  �ᨨ鼀�ᆠ �矄矄꾀    矄ᨨ鼀 鼀盐 㝐ᨨᆠ盐矄ᨨ  �矄꾀���     鼀矄矄 鼀 㝐ᨨᆠ盐矄ᨨ   �矄      ��ᨨ  m ��ᨨ 鼀ᨨ   鼀矄矄  �ᨨᨨ     矄ᆠ� �ᆠ 矄 ᔴ꾀   ᔴ 㡰 ᨨ �矄꾀 矄ᆠ�泐 �矄 ᲼㝐� 黨 ᔼ桌 㡰 䰘黨 㡰 �黨 ᆠ㡰 � 㡰 �䰘 黨

犨ᨨ�矄矄㜠�ᨨ  ᨨ鼀�ᆠ �盐矄䰘 鼀ᨨ鼀�ᆠ犨��  㡰   ᨨ  ᨨ鼀�ᆠ �盐矄҈ 鼀ᨨ鼀�ᆠ犨�� ҈㡰    矄鼀 盐鼀  矄�泐       矄鼀 鼀盐 �ᨨᨨ  �矄ᆠ�鼀  �鼀矄 �矄ᆠᨨ矄矄ᨨ ᲼㝐� 黨 ᔼᔼ桌 㡰 䰘 㡰 ҈ ᆠ㡰  㡰 䰘 ҈ ᨨ  �ᆠ矄  �ᨨᨨ  鼀  �鼀t �鼀犨 犨ᨨ矄盐ᆠᆠ矄矄�ᆠᨨ�矄�ᨨ 矄㡰 ᨨ 鼀ᨨᆠ盐矄 ᨨ  � �矄矄 盐 ᆠ�ᨨ ᨨ 鼀盐 T㡰⼄盐��泐 �矄 ෌ 矄矄ᆠ 鼀�ᆠ  ᨨ 犨 ᨨ矄ᆠ㡰 ᲼㝐�  ᔼ桌 

MCQs with One Correct Answer

�  黨 RT 㡰 㡰 RT ᆠ㡰 RT 㡰 RT   

ᨨ�矄 鼀盐ᨨ ᆠ� 鼀矄矄ᨨ �矄泐� ᔴ ᆠᨨ 矄 矄矄盐҈ᆠᨨ�矄ᨨ  �矄⼄盐�  ␔   矄鼀鼀矄矄ᨨ �矄�矄ᆠᨨᨨ 泐҈ ᔴᆠᨨ 矄  ᨨ盐鼀ᆠᨨ�矄ᨨ  �矄矄 ᨨ犨鼀 泐 �矄 ᨨ   ᨨ鼀 ᨨ矄ᆠ 鼀ᨨᆠ盐ᨨ  �矄�矄  矄矄盐鼀 �矄ᨨ� 㡰䁸 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 � 㡰  ᆠ㡰  㡰 䰘

t

t

㡰

㡰 ҈ T

T

t

t



ᆠ㡰 ҈ T

T

҈҈ ᔴᨨ 矄� 鼀� 盐ᨨ n鼀ᨨ矄ᨨ  �盐鼀�矄 n鼀ᨨ矄 ᨨ ᨨ 泐� �矄 鼀ᨨᆠ盐矄├ ᨨ��� 㡰矄 �  �矄ᔼ矄CP⏌CV盐犨� ᲼㝐�  ᔼᔼ桌 㡰 ҈黨⏌҈ 㡰 䰘⏌� ᆠ㡰 ⏌䰘 㡰 ⏌҈�

WWW.JEEBOOKS.IN

P-123

Kinetic Theory

҈

Cp �

犨ᨨ鼀ᨨ矄ᨨ  � �矄犨�  C = 鼀�  犨�   V Cp  鼀ᨨ矄ᨨ  ᨨ � �矄犨�  C =  盐ᨨ  V

Cp

҈

҈

҈�

҈

 ᨨ 鼀� 盐�矄 ᲼㝐� 䰘 ᔼ桌 CV 㡰 ҈� 㡰 ҈� ᆠ㡰 ҈䰘 㡰 ҈

犨ᨨ鼀ᨨ矄 ᨨ  �盐鼀 �矄 �矄 鼀�   犨�    鼀ᨨ矄 ᨨ 泐 ᨨ� 鼀ᨨᆠ盐矄 ├ ᨨ��� 㡰␔ �矄 鼀ᨨ 矄ᆠ� �ᆠ ᨨ 鼀� 盐ᆠᨨ 矄 ᨨ盐鼀䁸 㦨⏌鼀ᨨ⧤㡰 ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 ҈黨䰘⏌鼀ᨨ 㡰 ҈�䰘⏌鼀ᨨ⧤ ᆠ㡰 ҈䰘⏌鼀ᨨ⧤ 㡰 ҈⏌鼀ᨨ⧤ 꾀 �ᨨ鼀�ᆠ�矄犨� ��� 鼀ᨨᆠ盐矄 ᨨ矄҈ᨨ 犨ᨨ├ 犨     ᆠᨨ 矄 矄矄盐␔ 犨ᨨ盐    �泐矄ᨨ 泐 �矄�  �矄ᨨᆠ矄矄䁸 ᲼㝐� ҈꾀�҈黨ᔼᔼ桌 㡰 � 㡰 � ᆠ㡰  㡰  꾀�맔҈鼀ᨨ盐鼀ᆠ泐� �矄 � 犨� ҈鼀ᨨᨨ 졠 �矄ᨨᨨ鼀鼀盐 ⧤㡰 鼀ᨨᆠ盐 �鼀 ᨨ 졠 �矄ᨨᨨ鼀 矄⼄盐矄  ᨨ盐 ᨨ

鼀 鼀⏌矄矄ᆠ�泐␔ �矄 �ᆠᨨ�矄�ᨨ

 矄ᆠᨨ 㡰 ᨨ 졠鼀ᨨᆠ盐䁸 ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 ~҈҈ 㡰 ~҈҈҈ ᆠ㡰 ~҈҈ 㡰 ~҈҈ ␔    턼 �矄 矄盐�  ᨨ  �ᨨ鼀�ᆠ �矄 ᨨ  ��� 鼀ᨨᆠ盐矄ᆠᨨ 矄 ᨨ盐鼀�矄鼀盐� ᆠ矄矄 泐D   ⼄盐� ᨨᨨ 盐ᆠ 矄鼀ᆠ  ��

鼀盐ᆠᨨ 矄 矄矄盐�矄 ᲼㝐� ҈꾀�҈黨ᔼᔼ桌  � 䰘  Q Q Q  㡰 ᆠ㡰 㡰 Q   � 

 矄ᆠ� �ᆠ 矄 ᔴ p   ᔴv  ᨨ   �矄 ᨨ  �ᨨ鼀�ᆠ 鼀ᨨᆠ盐矄꾀��  � 盐 �矄ᨨ 鼀ᨨ҈├҈㡰泐黨 矄ᆠ�泐꾀 ᨨ �矄ᨨ  �ᨨ鼀�ᆠ鼀ᨨᆠ盐矄 矄 ᆠᨨ矄ᨨ � �盐矄 ҈ᔼ  泐 矄� �矄矄   ᲼㝐� 黨꾀�҈黨ᔼᔼ桌 㡰 꾀�矄��� 盐 矄��ᨨ 鼀ᨨ  㡰 꾀 矄��ᨨ 鼀ᨨ 盐 矄 ᨨ  ᆠ㡰 꾀 矄ᨨ ��ᨨ 鼀ᨨ   矄犨ᨨ 㡰 ᨨ 꾀  ��ᨨ 鼀ᨨ ᆠ  꾀 � �矄ᨨᆠᆠ盐�矄ᨨ盐鼀ᨨ 鼀 矄矄盐ᨨ  맔҈  �泐ᨨ  �矄 ᲼㝐� ҈ ҈黨ᔼ桌 㡰 黨맔҈ 㡰 맔҈ ᆠ㡰 ҈ 㡰 맔҈ 꾀 � �矄�矄 ᆠᨨ矄 � ᆠ泐� 矄矄盐ᨨ 鼀  鼀盐⧤ 鼀  �鼀犨  犨ᨨ 矄盐ᆠᆠ矄矄�ᆠᨨ�矄�ᨨ 矄�矄맔҈矄ᔼ  矄矄盐�矄 ᨨ盐   鼀盐 �矄� ᆠ矄  ᨨ� ⧤  鼀  �鼀 犨 犨ᨨ矄盐ᆠᆠ矄矄�ᆠᨨ�矄�ᨨ 矄犨��ᆠᨨ矄ᨨ ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 맔҈䰘矄 㡰 맔҈矄 ᆠ㡰 �맔҈矄 㡰 맔҈矄

㡰 ҈䰘

҈

҈黨

 꾀�矄鼀� 盐ᆠᨨ 矄�矄矄ᨨ 鼀ᨨ矄ᨨ ᨨ 泐�  �鼀ᨨ矄 ᨨ �ᨨ 鼀盐 ᔴᨨ 矄� � �ᨨ 泐 矄�ᨨ    ᨨ�ᨨ  鼀ᨨ 矄   ᨨ �    �泐ᨨ    矄泐矄鼀�矄 ᲼㝐� ҈҈ ҈黨ᔼ桌 㡰 ҈�

㡰 ҈

ᆠ㡰 

㡰 

҈ 犨ᨨ├�ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ�矄�矄矄矄盐ᨨ 맔҈ ⏌鼀     矄�泐 ᨨ   �矄 �矄  ├�⏌鼀 ␔  �矄   ᨨ  ᨨ   �泐ᨨ    �矄 盐 ᨨ�矄  鼀 鼀ᨨ�ᨨ 䁸 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 ҈ 㡰 ҈� ᆠ㡰 ҈ 㡰 ҈  꾀 ҈� � 鼀矄矄 ᨨ  �ᨨ� �矄 �矄  ᆠᨨ矄 �  矄矄  鼀盐䰘 ᔴ꾀鼀ᨨ盐 ᨨ   矄  ᨨ  �矄 矄ᨨ   鼀矄 ᨨᆠ�泐 ᨨ  鼀ᨨᆠ盐矄 �矄 ᨨ盐  �矄 ᨨ盐᲼ ├ 㦨⏌⧤鼀ᨨ桌᲼㝐�  黨  ҈黨 ᔼᔼ桌 㡰 黨├ 㡰 ├ ᆠ㡰 ҈├ 㡰 ҈├  犨ᨨ鼀ᨨ矄ᨨ  � 鼀ᨨ ᨨᨨ鼀�ᆠ�矄ᨨᆠᆠ盐�矄ᨨ盐鼀 䰘 ᔴ �矄  矄 ��ᆠ泐ᨨᨨ盐鼀 ᔴᆠ盐 ҈㡰  � 鼀盐ᨨ  �矄  㡰ᆠ  � � �矄�   �泐 ᲼㝐� ҈桌 㡰 ҈㡰҈黨⧤ 㡰 䰘├ 㡰 ҈㡰҈黨�⧤ 㡰 䰘├ ᆠ㡰 ҈㡰҈黨⧤ 㡰 䰘├ 㡰 ҈㡰҈黨�⧤ 㡰 䰘├  犨ᨨ鼀ᨨ矄 ᨨ  �盐鼀  鼀�   犨�   犨�  鼀ᨨ矄 ᨨ ᔴ  泐 ᨨ� ᔼ   =  ᨨ 鼀� 盐   盐ᨨ 

ᔴ  �矄 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ⏌ 㡰  ᆠ㡰 ҈ 㡰  � ᔴ  ᔴ  矄ᆠ� �ᆠ 矄  ᆠᨨ 矄  矄矄盐  ᆠᨨ 矄 ᨨ盐鼀矄ᆠ�泐ᔼ�矄ᨨ矄   ᔴᔴ㦨 ᨨ 泐 ᨨ� �矄 ᔴᔴ㦨 ᨨ �ᨨ� �矄

ᆠᨨᆠ�ᨨ 犨  �矄 ᲼㝐� ҈䰘桌 㡰 㦨҈ 㡰 㦨 ҈ b 㡰 㦨 ҈  꾀  �  �矄 矄鼀ᨨᆠ盐矄犨�  � �矄ᨨ   ᨨ鼀

�ᨨᨨ 矄ᆠ� �ᆠ 矄ᆠᨨ 矄 矄矄盐 ᔴ㡰  ᆠᨨ 矄 ᨨ盐鼀 ᔴ㡰�矄 ᲼㝐� 졠 � 꾀�҈䰘桌

ᆠ㡰 a =

䰘 䰘 � ᆠ㡰 㡰 �   䰘 꾀 � �矄盐 �ᨨ矄⼄盐矄�矄�ᆠ矄�ᨨᆠ矄矄 � 犨 �ᆠ �矄鼀ᨨ ᆠᆠ�泐ᔴ鼀� 矄ᆠᨨ 矄 ᔼ 盐� � �矄ᨨᆠ矄矄 �ᨨ ᨨ 矄矄盐 ᨨ盐鼀 �矄�� 泐 㦨ᆠᨨ 矄    �矄�� 泐 ᔴ  ᔴ鼀ᨨ矄ᆠ� �ᆠ ᆠᨨ 矄 矄矄盐 ᆠᨨ 矄 ᨨ盐鼀矄ᆠ�泐㡰 ᲼㝐� ҈桌 ᔴ - ᔴ ᔴ - ᔴ 㡰 = 㡰 = ᔴ - ᔴ ᔴ - ᔴ

㡰 

ᆠ㡰 =

㡰

ᔴ ᔴ

㡰 =

ᔴ  ᔴ ᔴ  ᔴ

WWW.JEEBOOKS.IN

EBD_8341 P-124



黨



Physics

矄� � ⼄盐���ᨨ  ᨨ   �泐   矄ᆠ� �ᆠ  � ├�҈⧤҈㡰ᨨ 盐鼀� �盐鼀ᨨᨨ鼀鼀盐ᆠ  矄�鼀 ᨨ ᨨ鼀�ᆠ犨�� ᨨ 盐鼀� �盐鼀㦨䰘㡰 ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 㡰 ҈ 㡰 � ᆠ㡰 ҈� 㡰 黨� 㝐ᨨ  ᆠ盐盐鼀盐鼀矄ᆠ ᆠ盐矄矄 ᨨ犨 ᨨ 矄矄盐ᨨ 맔҈҈�鼀ᨨᨨ鼀鼀盐 ⧤㡰

├� � 㦨⧤҈鼀ᨨ҈҈鼀㦨҈� 꾀ᨨ� ᨨ 㦨맔҈鼀ᨨ҈ 鼀  �矄 ᆠ犨 鼀ᨨᆠ盐矄 ᨨ �矄�  ᆠ盐 矄矄犨�ᨨ  ᨨ ᨨ  ᲼㝐� 졠 � 꾀�黨҈桌 㡰 m鼀 㡰 鼀鼀 ᆠ㡰 ᆠ鼀 㡰  鼀 ��盐矄 ᨨ犨矄 ��ᨨ � 鼀盐 D 㡰犨�   鼀ᨨ盐  ᨨ   矄盐�  턼㡰 �    �矄ᨨ�ᆠ ᨨᆠ矄矄 ᆠᨨ矄ᨨ � �ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ 㝐㡰 �ᨨ鼀�ᆠ 㡰  ᨨ泐ᨨ鼀�ᆠ 㡰�矄 � ��矄ᨨ  �矄矄  矄鼀  矄ᆠ矄 ᨨ 犨ᨨ 矄ᆠᨨ� ᆠ� ᔼ� ᨨ� � ��ᨨ  �矄 ᨨ   ᨨ鼀  � 矄 a b   c 矄ᆠ�泐ᆠᨨ矄ᨨ ᨨ ᲼㝐� 졠 � 꾀�黨҈桌 a

3

b



c D

㡰 㝐  ҈







㡰 ҈ 㡰 ҈� ᆠ㡰 ҈� 㡰 䰘 � 꾀矄矄ᆠᨨ � 矄鼀� 盐ᨨ ᨨ 鼀ᨨᨨ ᨨ 泐�  犨ᨨ 鼀ᨨ矄 ᨨ  �ᨨ�    ⧤  �ᨨ ᨨ    � ᨨ�ᨨ ├� �ᆠ �泐졠鼀ᨨᆠ盐ᨨ  鼀ᨨᆠ盐�矄 ҈黨黨和㜠㝐├矄㡰 㡰 ҈҈ 㡰 ҈ ᆠ㡰 ҈ 㡰  矄 ᨨ    鼀ᨨ鼀 矄 ᨨ  � � ᨨ    犨ᨨ 鼀ᨨᆠ盐矄  犨ᨨᆠ泐� 矄A B � 犨� �矄ᨨ 矄ᆠᨨ � ⼄盐 鼀ᨨ盐 矄ᨨ  �  �ᨨ鼀�ᆠ�矄⧤ �矄ᨨ ᨨ A �矄 ᨨ鼀ᨨ犨 � B�矄   �   矄鼀鼀ᨨ盐  ᨨ  �矄�� ᨨ �矄� ᆠ ᆠ泐� ᔼ  �矄�

鼀盐 ᨨ    �矄 �  A �矄  ⧤     �矄 �

鼀盐ᨨ  �矄� B�矄 ᲼҈黨黨和㜠㝐├矄桌 ᆠ㡰 �⧤ 㡰 ⧤ 㡰 ⧤ 㡰 ҈⧤ 䰘 ␔   �  �ᨨ鼀�ᆠ�矄�矄  ᆠᨨ 矄 矄矄盐   ᆠ�ᨨ ᨨ    �泐矄盐� 犨 �ᆠ � ᆠ矄矄  �   �泐ᨨ  �矄�矄 ᲼҈黨黨㜠㝐├矄桌    � 㡰 㡰 ᆠ㡰 㡰 � � 䰘 䰘

㡰 㝐 

ᆠ㡰  㝐 㡰 㝐  꾀�矄鼀� 盐ᆠᨨ 矄�矄矄ᨨ 鼀ᨨ矄ᨨ ᨨ 泐�  鼀ᨨ矄ᨨ �ᨨ 鼀盐 �ᆠ� ���ᨨ 鼀ᨨ 矄  ᨨ�   �泐ᨨ  矄泐矄鼀�矄 ᲼҈黨黨黨和㜠㝐├矄桌 ᆠ㡰 黨

㡰 ҈҈

㡰 

㡰 ҈�

� 矄�ᨨ ├� �ᆠ �泐ᨨ 졠 � 鼀ᨨ鼀矄矄㡰鼀ᨨᆠ盐矄�ᆠ盐鼀盐�矄   矄�ᨨ ├� �ᆠ �泐ᨨ  � 鼀ᨨ鼀矄矄㡰鼀ᨨᆠ盐矄�  矄鼀鼀盐�矄 ᲼҈黨黨䰘㜠҈㝐├桌 㡰 ҈� 㡰  ᆠ㡰  㡰 䰘 ᨨ鼀  ᨨᨨ犨� �矄鼀 矄ᆠᨨ ᆠ � �� �矄 泐 �� 鼀盐 矄ᆠ ᆠᨨᆠᨨ  矄㡰᲼҈黨黨�和桌 㡰  ᆠᨨ �ᆠ�  ᨨ  ᨨ盐鼀   矄�ᨨ   ᆠᨨ 矄  矄矄盐�矄 矄鼀 ᨨ� �矄矄 㡰 � 矄�ᨨ ├� �ᆠ �泐鼀ᨨᆠ盐 ᨨ ᨨ 泐� �矄�矄├ ├� �ᨨ 鼀

ᆠᨨ 矄  ᆠ㡰  鼀 㜠    ᨨ  鼀ᨨᆠ盐矄 � ᆠ矄矄 犨� � ᆠ矄矄�  矄矄盐 㡰 ᔼ �矄ᨨ盐矄鼀� 盐 � 矄�ᨨ ├� �ᆠ  �泐ᨨ  鼀ᨨᆠ盐矄ᨨ ᆠ ᆠᨨ鼀ᨨ  �矄 �   �ö æ ᔼ ᨨ 鼀ᨨᨨ 鼀ᨨ ᨨ鼀�ᆠ�矄 ç g = ÷ �矄鼀�  犨� ᨨ  ø è 䰘ö æ 鼀ᨨᨨ  �ᨨ鼀�ᆠ�矄 ç g = ÷  盐ᨨ  g  ᨨ鼀� 盐 �ø è �矄 ᲼҈黨㜠҈㝐├桌

Numeric Answer

 꾀ᆠᨨ矄 矄矄ᆠᨨ � 矄҈鼀ᨨᨨ 鼀ᨨ ᨨ鼀�ᆠ�  �矄⧤ᔼ �鼀ᨨᨨ  矄鼀�矄⧤�矄  ᨨ�  � ⼄盐���盐鼀鼀盐 � ⧤㡰ᨨ  �矄�

 矄矄犨�ᆠᨨ矄ᨨ힘힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼ㡰桌 4

Fill in the Blanks

黨 졠 鼀ᨨᨨ 鼀ᨨ ᨨ㜠ᨨ鼀�ᆠ� �矄�矄鼀�  犨� ᨨ  鼀ᨨᨨ  �ᨨ鼀�ᆠ� �矄 鼀ᨨ矄ᆠ� �ᆠ ᨨ   鼀� 盐ᆠᨨ 矄 ᨨ盐鼀�矄 ᲼҈黨㜠㝐├矄桌 5

True / False

 꾀�� 鼀盐 矄ᆠ� �ᆠ ᨨ �矄ᆠᨨ 矄  矄矄盐�矄犨泐矄�  �矄矄ᆠ� �ᆠ ᆠᨨ 矄  ᨨ盐鼀 ᲼҈黨䰘㜠㝐├矄桌 6

MCQs with One or More than One Correct Answer

҈ 꾀ᆠᨨ � ᨨ  �  ᨨ盐鼀 矄鼀� 盐ᨨ ᨨ 鼀ᨨᨨ 泐 ᨨ�    ᨨ  鼀ᨨ ᨨ  �盐鼀 �  ⼄盐���盐鼀  鼀盐T꾀矄矄盐鼀� � �矄矄�  ᆠᨨᆠ 矄鼀  矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 � �泐鼀ᨨᨨ  �矄鼀� 盐�矄RT 㡰 �ᨨᨨ 矄 ᨨ 矄ᨨ盐 �  �矄鼀� 盐ᨨ  ᆠ㡰 㡰

�  �盐鼀�矄�矄  ⏌ �

�ᨨᨨ  鼀矄矄 ᨨ  �盐鼀ᨨ鼀矄ᨨ ᨨ 泐 ᨨ� 鼀ᨨᆠ盐矄�矄҈⏌

�ᨨᨨ  鼀矄矄 ᨨ  �盐鼀ᨨ鼀矄ᨨ ᨨ ҈ 泐 ᨨ� 鼀ᨨᆠ盐矄�矄 

WWW.JEEBOOKS.IN

P-125

Kinetic Theory

42.

Cv and Cp denote the molar specific heat capacities of a gas at constant volume and constant pressure, respectively. Then [2009] (a) Cp – Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas (b) Cp + Cv is larger for a diatomic ideal gas than for a monatomic ideal gas (c) Cp / Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas (d) Cp . Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas 9

43.

the product of its pressure and its volume. [2007] because Statement-2 : The molecules of a gas collide with each other and the velocities of the molecules change due to the collision. (a) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1 (b) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (c) Statement-1 is True, Statement-2 is False (d) Statement-2 is False, Statement-2 is True

Assertion and Reason Type Questions

Statement-1 : The total translational kinetic energy of all the molecules of a given mass of an ideal gas is 1.5 times

Topic-4 : Miscellaneous (Mixed Concepts) Problems 1 1.

2. 3.

Two moles of ideal helium gas are in a rubber balloon at 30°C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35°C. The amount of heat required in raising the temperature is nearly (take R = 8.31 J/mol.K) [2012] (a) 62 J (b) 104 J (c) 124 J (d) 208 J An ideal gas is expanding such that PT2 = constant. The coefficient of volume expansion of the gas is – [2008] (a) 1/T (b) 2/T (c) 3/T (d) 4/T When an ideal diatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas is [1990 - 2 Marks] 2 3 3 5 (a) (b) (c) (d) 5 5 7 7 3

4.

M1

MCQs with One Correct Answer

Numeric Answer

One mole of a monatomic ideal gas undergoes an adiabatic expansion in which its volume becomes eight times its initial value. If the initial temperature of the gas is 100 K and the universal gas constant R = 8.0 J mol –1 K –1, the decrease in its internal energy, in Joule, is__________.

M2

a

S

6 6.

MCQs with One or More than One Correct Answer

As shown schematically in the figure, two vessels contain water solutions (at temperature T) of potassium permanganate (KMnO4) of different concentrations n1 and n 2 (n 1 > n 2 ) molecules per unit volume with Dn = (n1 - n2 ) F4 㡰 F 1> F2 > F 3 >F4 ᆠ㡰 F 1= F2 = F 3 㦨F4 㡰 F 1> F 3 ; F 2 F4

��ᨨ 犨 犨ᨨᆠᨨ ᆠ �ᆠ矄 矄ᨨ  ��ἘἘ ἘἘ矄ᆠ�泐 矄 ��盐㡰 ᨨ盐鼀ᆠ �  矄�泐 꾀  㦨  犨 꾀�矄ᆠᨨ 矄  �矄  �矄 ᆠ ᨨ鼀   ᆠ 꾀 ᆠ ᨨ  矄 矄�矄ᨨ� ᆠ � 턼 盐ᨨ 꾀矄盐ᆠ   ᆠ�ᆠ � �  ��ᨨ

᲼㝐� ҈桌 犨  矄 矄犨�ᆠᨨ 矄 �矄

㡰

҈  p҈ p ҈  p҈ p 㡰  pe x pe x ҈  p҈ p ҈  p҈ p ᆠ㡰 㡰  pe x  pe x r ҈҈ ᔴᨨ 矄�  ᆠ�ᆠ �  E = E xˆ 犨 쟼�矄ᆠᨨ 矄 

 盐  ᨨ盐�  矄    矄矄 ᨨ犨 �   ��盐㡰 盐ᨨ �矄 � �矄 ᲼҈҈桌 㡰 Ea aa㡰

㡰

L x

D a

C

 a  y

O A

B

WWW.JEEBOOKS.IN

P-161

Electric Charges and Fields

3 ҈�

Numeric Answer

ur 꾀 ᆠ�ᆠ �  쟼 =  x�ˆ - y  + ҈㡰 ˆ ⏌ᔴ 矄矄矄 ᨨ盐�   ᨨ  矄 ᨨ犨  �  ��盐  盐 ᨨ   ᆠ�ᆠ �  ᨨ盐� 矄盐 ᆠ矄꾀ᔴ ᔴ෌ 鼀├ 矄f҈ f҈҈矄ᆠ�泐  �  ᆠ犨  f҈f҈҈㡰�矄 �

鼀⏌ᔴ㡰힘힘힘힘힘힘힘 ᲼㝐� 黨  ᔼᔼ㡰桌 꾀 㡰 㡰



҈

҈䰘

҈



㡰

㡰 ᆠ�ᆠ 盐  ᨨ盐�  矄 �矄  l ⏌Î 㡰  㜠ᆠᨨ鼀ᨨ  ᨨ  ᆠ�ᆠ � �矄 ᨨ  ᨨ� 矄ᨨ  矄盐 ᆠᨨ  矄  ᆠ㡰 ᆠ�ᆠ 盐  ᨨ盐�  矄 �矄  l ⏌Î 㡰 ᆠ�ᆠ � �矄 ᨨ鼀ᨨ 矄盐 ᆠᨨ  矄  ᨨ� 矄 ҈黨 꾀ᨨ� ᆠ �졔턼�矄ᆠ 盐矄ᨨ盐矄�  �鼀�� 泐 鼀�矄 �ᆠ矄盐 ᆠᨨ  �盐矄 矄矄 ᨨ犨 �   ��盐 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄⏌ᆠᨨᆠ䁸 턼 ᲼꾀 ҈䰘桌





㡰 쟼 㡰 㡰  ෌ 㡰 㡰

꾀ᆠ�ᆠ盐 �矄ᆠᨨ  �盐矄Rᆠ�矄矄盐 ᆠᆠ �  矄�泐 rö æ s r 㡰 = s ç҈ - ÷  犨 s �矄ᆠᨨ 矄  r�矄   è Rø �矄 ᆠ ᨨ鼀 ᆠ ᨨ   �矄ᆠ쟼ᆠ�ᆠ 盐  ᨨ盐�  � 矄 �ᆠ 矄盐 ᆠ    ᆠᨨ矄矄   ᆠ �  �矄ᆠ ᆠᨨ鼀泐�矄f쟼ᆠ�ᆠ 盐  ᨨ盐�  ᨨ 矄 �ᆠ R 矄盐 ᆠᨨ  �盐矄  ᆠᨨ ᆠ �ᆠ犨�    �矄ᆠ�矄f  f

  �ᨨ �矄힘힘힘힘힘힘힘힘힘  ᲼꾀 桌 f 6 MCQs with One or More than One Correct Answer 꾀ᆠ � 矄 ᨨ  �盐矄 ᆠ�矄ᨨᆠ �턼෌�

f矄  盐 ᨨ ᆠ�ᆠ �  ᨨ盐� ᆠᨨ矄 ᆠ泐� �ᆠ 矄盐 ᆠᨨ  �� h �盐矄r 犨� �矄ᆠ 矄鼀矄  ᨨ  矄 ᆠ ᨨ  ᆠ泐� �矄ᨨ� ᨨ

  �矄ᨨ  ᆠ泐� 犨 �ᆠ �矄⼄盐� �矄  ᨨ鼀�矄ᨨ   ᨨᨨ鼀 矄盐 ᆠ矄␔ �ᆠ  ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄㡰 ᲼꾀 ҈黨桌 �矄⏌ᆠᨨᆠ䁸 ᲼e�矄 鼀���泐ᨨ  矄ᆠ桌 㡰 ᔼ h>R r 㦨R⏌�  f㦨턼⏌�e 㡰 ᔼ h>R r>R  f㦨턼⏌e ᆠ㡰 ᔼ hR⏌� r㦨R⏌�  f㦨 㡰 ᔼ h>R r>R / 5  f㦨턼⏌�e 꾀 � � �泐ᨨ � �  ᨨ 㜠ᆠᨨ 盐ᆠ� �犨��矄ᨨ   㜠 �矄 ᆠ�矄盐 � ᨨ鼀� ᆠ �  矄�泐lᔼ �ᆠ矄 �  ᨨ 㜠ᆠᨨ 盐ᆠ� �矄 �ᆠ矄 ᨨ  �盐矄 � 矄盐ᆠ 犨泐  ᆠ턼矄盐 矄  �҈   ᆠ 졠ᨨ  矄 �ᆠ矄 矄矄 ᨨ犨 �   ��盐

 鼀���泐 ᨨ   矄ᆠ �矄 Î   ␔ �ᆠ  ᨨ    ᲼꾀 ҈桌 ᨨᨨ犨� �矄鼀 矄�矄 㡰盐䁸



l 



㡰

ᆠ�ᆠ 盐 矄矄� � ᨨ盐�  ᆠ盐 矄盐 ᆠ

턼 æ ҈ ö ç҈ ÷ e è ø 㡰 ᨨ 盐  ᨨ盐�  ᆠ盐    矄盐 ᆠ矄 턼 �矄 e  ᆠ㡰 ᆠᨨ鼀ᨨ  ᨨ  ᆠ�ᆠ �  ᨨ鼀ᨨ   矄盐 ᆠ�矄ᆠᨨ 矄 ᨨ 矄盐 ᆠ 㡰 ᆠ�ᆠ盐鼀  ᆠᨨ   矄盐 ᆠ�矄 ⼄盐�ᨨ �

ᨨ   鼀�矄 �矄 -

 꾀 ᆠ盐�ᆠ ��ᨨ  ᨨ 矄�  a 矄 �矄ᆠ    ᨨ���  ᔼ ᆠᨨ矄矄  �  ᨨ� ᆠ �矄-q -a⏌㡰졔q    㡰   -q    졔a⏌ 㡰 ᔴ ᨨᨨ矄   ᆠᨨᆠ ᨨ�ᨨ 矄 矄㡰 ᲼҈桌 z  a q  

q

q 

x

㡰   ᆠ�ᆠ 盐  ᆠᨨ矄矄� �     x 㦨 졔a⏌ �矄⼄盐ᨨ  ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  x㦨-a⏌ 㡰  ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  y㦨졔a⏌�矄鼀ᨨ     ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  y㦨-a⏌ q ᆠ㡰  ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  ���ᨨ �矄 e 0 㡰  ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  z 㦨졔a⏌�矄⼄盐 ᨨ  ᆠ�ᆠ 盐 ᆠᨨ矄矄� �  x㦨졔a⏌ ҈ 꾀 �矄ᨨ� ᆠ�泐�矄ᆠ 犨� �  ᆠᆠᨨ 盐ᆠᨨ 꾀ᨨ矄��ᆠ �q�矄ᆠ  ᆠ ᨨ  ᆠ�泐

ᨨ� 矄A Bᨨ  ᆠ�泐矄盐 ᆠ矄矄 ᨨ犨 �

  ��盐 

᲼҈黨黨黨和㜠㝐├矄桌

ᨨ  졠  ҈

턼

A

q

B

WWW.JEEBOOKS.IN

EBD_8341 P-162

Physics

(a) electric field near A in the cavity = electric field near B in the cavity (b) charge density at A = charge density at B (c) potential at A = potential at B (d) total electric field flux through the surface of the cavity is q/e0

ur 22. The magnitude of electric field E in the annular region of a charged cylindrical capacitor. [1996 - 2 Marks] (a) is same throughout (b) is higher near the outer cylinder than near the inner cylinder (c) varies as 1/r, where r is the distance from axis (d) varies as 1/r2 where r is the distance from the axis.

Topic-4 : Miscellaneous (Mixed Concepts) Problems 1 1.

2.

Dl    鼀ᨨ�ᨨ ᨨ P�矄᲼҈黨黨和㜠㝐├矄桌 㡰 �ᨨ �ᆠ ᨨ盐矄ᨨ z矄�矄 泐� �z¥ 㡰 矄�鼀 鼀ᨨ �ᆠ ᨨ盐矄ᨨ z矄�矄 泐� �z£R ᆠ㡰 ᨨ �鼀泐矄�鼀 鼀ᨨ �ᆠᨨ�  zR 㡰 矄盐ᆠ  Pᆠᨨ矄矄矄O ᆠᨨ � 盐矄ᨨ鼀ᨨᨨ �   ��z �矄ᨨ犨 矄 z = - ¥

Answer Key Topic-1 : Electric Charges and Coulomb's Law ҈ 㡰 ҈ ҈°

 㡰

KQ L

㡰 ҈҈

 㡰 矄 ҈

 ᆠ㡰

� 㡰

 㡰

盐 ҈ ᆠ㡰 ҈

㡰 ҈�

䰘 㡰

 㡰

黨

҈ q 㡰 pÎ L

㡰

Topic-2 : Electric Field and Field Lines ҈ ҈҈ ҈ ҈ ҈

ᆠ㡰 㡰 㡰 矄 㡰

 ҈   

ᆠ㡰 㡰 㡰

盐 㡰

 ҈   

ᆠ㡰 㡰 ᆠ㡰

盐 㡰

 ҈   

ᆠ㡰 � 㡰  㡰 㡰 ҈� 㡰 ҈ ᆠ㡰 ᆠ㡰 � 㡰  ᆠ㡰 ᆠ㡰 �  㡰  㡰 ᆠ㡰

䰘 ҈䰘 䰘 䰘

ᆠ㡰 㡰 ᆠ㡰 ᆠ㡰

 ҈  

㡰 黨 ᆠ㡰 ҈黨 㡰 黨  㡰 黨

㡰 㡰 㡰  㡰

҈   

ᆠ㡰 㡰 ⼄쟼꾀㡰 ᆠ㡰

Topic-3 : Electric Dipole, Electric Flux and Gauss's Law ҈ 㡰  㡰 ҈҈ ᆠ㡰 ҈ 㡰 ҈ ᆠ 㡰  ᆠ㡰

 㡰 ҈ 㡰

 㡰 ҈ 㡰

� 㡰  㡰 䰘 㡰  ᆠ㡰 ҈� 㡰 ҈ 㡰 ҈䰘 ᆠ㡰 ҈ 㡰

黨 ᆠ㡰 ҈ ᆠ㡰 ҈黨  㡰  ᆠ 㡰

Topic-4 : Miscellaneous (Mixed Concepts)Problems ҈ 㡰

 㡰

 㡰

 ҈㡰

� 矄

 ᆠ㡰

䰘 㡰

 ᆠ㡰

WWW.JEEBOOKS.IN

EBD_8341 P-164

Physics

16

Electrostatic Potential and Capacitance

Topic-1 : Electrostatic Potential and Equipotential Surfaces 1 ҈





r

 ᆠ �矄ᆠ ᨨ  ᆠ�ᆠ盐鼀  ᆠᨨ ᆠ�ᆠᨨ  �盐矄 R 犨�  ᆠᨨ 矄   �盐 矄�ᨨ  犨

矄盐ᆠᆠ矄矄�ᆠ �矄꾀 ᆠ �矄҈�䰘黨  ᆠ � 졔q㡰ᆠ 犨 �҈ ᆠ � q㡰ᆠ 

ᨨ �V  ᆠ�ᆠ � E ᆠ ᨨ   ᆠ�ᆠ矄ᆠ�泐 ├V㦨� � �泐㡰 ᲼㝐� 和� ᔼᔼ㡰桌 ҈q 錐 E = 㡰 V = pe  R ҈ q 㡰 V = 錐 E = pe  R  ᆠ㡰 V㦨錐E㦨 ҈ q ҈ q 㡰 V = 錐E=  pe R  pe  R  

犨ᨨ�矄ᨨ ᆠᨨ 盐ᆠ� �矄 矄S҈ Sᨨ  �盐矄 R  ҈ R    ҈mᔴ mᔴᆠ �矄矄ᆠ�泐   � �矄 ᆠ ᨨ鼀ᆠ ᨨ  泐 ᨨ犨ᆠᨨ

ᆠ 泐 ᆠᨨ 盐ᆠ� �犨�꾀ᨨ ��鼀  �矄�矄 ᨨ  ᆠ �矄ᨨ

S҈ S矄ᆠ�泐 [Main Sep. 03, 2020 (I)] 㡰 �mᔴᨨ ᨨ 㡰 졔�mᔴ �mᔴ ᆠ㡰 mᔴ mᔴ 㡰 mᔴ mᔴ ᔴᨨ ᆠ �ᆠ鼀�ᆠ ᨨᨨ犨矄 矄ᨨ  ��R R ᨨ ᆠ �矄Q҈ Q矄ᆠ�泐෌�  矄盐 ᆠᆠ �  矄��矄ᨨ  ᆠᨨ ᆠ �ᆠ矄 矄⼄盐 ᨨ � �  ᆠV R㡰V R㡰�矄 ᲼㝐� 和 ᔼᔼ㡰桌 㡰



MCQs with One Correct Answer

Q Q Q҈ 㡰 ᆠ㡰 pe R pe R ҈pe  R



Q҈ pe R

꾀ᆠ �Q�矄 �矄�盐 ᨨ犨ᨨᆠᨨ ᆠ �ᆠᆠᨨ 盐ᆠ� �  � 矄 �ᆠ矄 矄 ��r R R  r㡰ᔼ  矄盐 ᆠᆠ �  矄��矄ᨨ  犨ᨨ矄 矄⼄盐 ᆠ�ᆠᨨ �  ᆠᨨ鼀鼀ᨨ ᆠ �矄 ᲼㝐� 和 ᔼᔼ㡰桌

R

҈  R + r 㡰 ҈ R + r 㡰 Q Q 㡰    pe R  + r  㡰 pe   R + r 㡰 ҈ R + r 㡰 ҈ R +  r 㡰Q Q ᆠ㡰 㡰   pe R  + r  㡰 pe   R + r 㡰 꾀盐 � ᨨ鼀泐ᆠ � � �ᨨ  �盐矄 ᨨᆠ �⼄ �矄ᆠ �  泐㜠 ᆠ  ᨨ��� 꾀ᨨ� ᆠ �⼄�矄 鼀ᨨ� �ᨨ犨 矄 � �ᨨ �  㜠 �矄  矄矄   㦨 鼀� �鼀盐鼀盐ᨨ 矄盐ᆠ  �ᆠᨨ矄矄矄  ᨨ��� �矄 ᲼㝐� ҈꾀�҈黨ᔼ桌

㡰

�

҈⏌

㡰

 æ  ⼄ ö ç ÷ 鼀 è ҈� pe ø

ᆠ㡰

 æ  ⼄ ö ç ÷ 鼀 è ҈� pe ø

҈⏌

㡰

 æ ҈ ⼄ ö ç ÷ 鼀 è � pe ø



 æ ҈ ⼄ ö ç ÷ 鼀 è ҈� pe ø

҈⏌



䰘

҈⏌

꾀 矄ᨨ�  ᆠᨨ 盐ᆠ� � 矄  � �  ᆠ � 턼 �矄 矄盐ᨨ盐  泐 盐 ᆠ � ᆠᨨ 盐ᆠ� � ᨨᨨ犨矄 �ᆠ 矄  ᨨ � �  ᆠ犨  矄盐 ᆠᨨ  矄ᨨ� 矄   ᨨ  ᨨ盐矄盐 ᆠᨨ   ᨨᨨ犨 矄 ᔼ  矄 �矄 ᨨ犨�� ᆠ �ᨨ 턼 

犨ᨨ � �  ᆠ犨  矄鼀犨ᨨ矄盐 ᆠ矄 �矄 ᲼㝐� 꾀�҈黨ᔼ桌 㡰  㡰  ᆠ㡰  㡰  r

ᆠ�ᆠ � � ��ᨨ �矄�� 泐 쟼 = ( 꾀x +  ) �ˆ  犨 쟼�矄�  ᔴ҈   x �矄 � 鼀矄   盐矄 ᨨ ᆠᨨ 矄 矄꾀㦨和ᔼ盐 � 㦨҈和ᔼ盐 �ᔼ   ᨨ �x㦨҈�矄҈  x 㦨��矄  

҈�矄  ᲼㝐�  ҈黨ᔼᔼ桌 㡰  㡰  ᆠ㡰 ҈ 㡰 �

WWW.JEEBOOKS.IN

P-165

Electrostatic Potential and Capacitance



�� � 矄 ᨨ犨矄��ᨨ  犨�  �矄 ᆠ ᨨ鼀ᆠ 㡰 ᨨ  ᲼㝐� ҈҈ ҈黨ᔼ桌 졠

҈

졠

黨



㡰 쟼ᆠ�ᆠ � ᨨ 盐 � ᨨ鼀泐ᆠ � 矄  㡰 ᨨ �ᨨ 盐 � ᨨ鼀泐ᆠ � 矄 �ᆠ矄  ᆠ㡰 ᨨ �ᨨ 盐 � ᨨ鼀泐ᆠ � 矄  㡰 쟼ᆠ�ᆠ � ᨨ 盐 � ᨨ鼀泐ᆠ � 矄 �ᆠ矄 

犨ᨨᆠ�ᆠ �ᨨ矄꾀犨� 矄ᆠ� �ᨨ鼀ᨨ鼀 矄 r r 꾀 =   ⼄ �ˆ    =   ⼄ �ˆ ᆠ ᨨ  x㜠 �矄 犨� 矄�ᨨ  矄矄 ᨨ犨 �   ��盐

҈

 �矄 ᆠ ᨨ鼀꾀犨 �ᆠ ᨨ ᨨ  鼀ᨨ 盐ᆠ  矄鼀ᨨ ��矄 ᲼㝐� ҈ ҈黨ᔼ桌   㡰 ᆠ㡰 㡰 㡰  +҈  -҈  +҈  -҈ 꾀 �  矄 �ᆠ � 矄盐� � 矄  ᨨ   �盐矄 ᆠ�矄 盐 � ᨨ鼀泐 �矄�盐 ᆠ �矄盐ᆠ   ᨨ ��矄 矄盐 ᆠ�矄꾀 ᨨ犨� 矄鼀apR a ҈㡰�矄 鼀 ᨨ  矄 犨� ᨨ盐 ᆠ� � 矄ᨨ  矄  ␔ �ᆠ ᨨ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄ᆠᨨᆠ䁸 ᲼꾀 ҈黨᲼ 㡰 鼀� �盐� ᨨ ᆠ�ᆠ � ᨨ� ᨨᆠ ᨨ

� 矄矄� � ᨨ盐�   ᨨ 矄 矄ᆠ ᨨ

 �矄 ᆠR ᨨ鼀 ᆠ ᨨ  矄 �ᆠ矄  aV 犨� 盐ᆠ 泐  R 㡰 �ᨨᨨ  ᨨ � ᆠ ᨨ  矄 ᨨ ҈  ᨨ  ᨨ�  R  ᨨ鼀 ᆠ ᨨ犨 矄   ҈- a ᨨ犨� ҈ - a ᆠ㡰 鼀� �盐 ᨨ ᆠ�ᆠ �  ᆠ ᨨ   aV R 㡰 ᨨ � ᆠ ᨨ  矄 �矄 盐ᆠ 泐 aV

ᆠᨨ ᆠ �ᆠ鼀矄 矄꾀 ᔴᨨ 矄ᆠ� �� ab c abc㡰 矄盐 ᆠᆠ �  矄��矄졔ss  졔s 矄ᆠ�泐 ᨨ �ᨨ 矄 �矄 ᲼҈桌 s é   -  ù s é  -  ù 㡰 Î ê  졔ᆠ ú 㡰 Î ê  졔ᆠú úû úû  êë  êë     ù ù s é -ᆠ s é - ᆠ ᆠ㡰 Î ê  졔 ú 㡰 Î ê ᆠ 졔 ú  ëê  ëê ûú ûú

 �矄  盐 � ᨨ鼀 ᆠᨨ矄�ᆠ �  �   ��ᨨ   ᨨ ��ᨨ盐矄ᨨ� 矄ᨨ 矄鼀矄 ᆠ   �  ��ᨨ �矄 ᨨ盐 ᨨ泐犨 �  �鼀�矄�黨

矄 �矄 盐ᆠ 泐

҈҈

҈

҈

҈�

҈

҈䰘

ᨨ�黨␔ �矄 ᨨ �ᨨ� ᨨ  矄  犨 ᨨ矄 �盐矄ᆠᨨ鼀├矄  �ᨨ  犨�   �ᆠ�ᨨ

ᨨ   � 䁸 ᲼㝐� 졠 � 꾀�҈䰘桌 㡰 �黨� 㡰 �黨 ᆠ㡰 �黨 㡰 �黨

ᨨ � � ᨨ矄㡰ᨨ ᆠ � �矄�盐�ᨨ �矄�� 泐  㡰㦨�  ᨨ £҈鼀  㡰㦨�҈  ᨨ ³ ҈鼀  㡰 ᨨ矄 ᨨ   ᨨ     泐 ᔼ   �矄 ᨨ � �矄 �   泐 ᆠᨨ 矄  ᆠ �  盐 � ᨨ盐鼀 r �

盐 �矄ᨨ e㡰犨 �ᆠ  �矄矄 ᨨ ᆠ� ��ᨨ   

ᆠ ᨨᨨ矄 ᆠᨨᆠ矄鼀 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 r㦨e�   ���ᨨ

㡰 r㦨҈e ᨨ £҈鼀 㦨矄犨  ᆠ㡰 r㦨e ᨨ £҈鼀 㦨矄犨  㡰 r㦨e�   ���ᨨ

꾀 盐 � ᨨ鼀泐 ᆠ �  矄ᨨ�  矄  ᨨ   �盐矄  矄 ᨨ � 鼀矄盐 犨� 矄ᆠᨨ¥㡰ᨨ �矄矄盐 ᆠ ᨨ �矄矄  ⼄盐�ᨨ �矄盐 ᆠ矄犨� ᨨ �矄  �         �盐矄 ҈         矄ᆠ�泐 

᲼㝐� ҈�桌 㡰 ҈㦨    㡰 㡰  㦨  ᆠ㡰 ҈㦨  >  㡰 㡰 ҈¹   ҈㡰>  㡰 r -1  �矄矄� ��ᨨ ᨨ $ 꾀 ᆠ�ᆠ �  E = (25i$ + 30j)NC 矄ᆠ ᔼ  ᨨ �   ᨨ���  �矄 ├  ᨨ ᨨ    ᨨ � x㦨 m y㦨 m�矄  ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 㡰 ҈҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈ r 꾀矄矄盐鼀  ᆠ�ᆠ �  쟼 =   ˆ�  �矄矄� 矄ᆠ 

 ᨨ � �  ᆠ 꾀 - 졠  犨  졠 �矄 ᨨ �  ᨨ���   꾀  ᨨ � 㦨鼀�矄᲼㝐� ҈桌 㡰 ҈⏌ᔴ 㡰 ҈⏌ᔴ ᆠ㡰 ⏌ᔴ 㡰 ⏌ᔴ

犨ᨨ 矄鼀 ⼄盐 ᨨ�  ᆠ �矄 ᨨ  鼀� �盐  q  矄盐矄   ᨨ鼀  ᆠᨨ鼀鼀ᨨ  ᨨ�  ᨨ    ᆠ�� � 泐 � 矄盐� �鼀矄矄矄矄矄� �矄ᨨ ⼄盐 � 矄 泐ᆠᨨ鼀 ᨨ⼄盐���盐鼀犨� ᆠ 矄� �鼀├� � �q ᨨ鼀  �ᆠ ᔼ    鼀矄矄 ᨨ  ᆠ  ᆠ � �矄 m      ᆠᨨ矄�ᆠᨨ � ᆠ ᨨ � ᨨ� � � 鼀犨� æ

ö ҈ = k÷ p Î  è ø 

 ç

᲼㝐� 졠 � 꾀�҈桌

㡰  k mg  q

㡰

k mg  q

ᆠ㡰  k mg ⏌  q 㡰 k mg ⏌  q ҈ 꾀ᨨ � ᨨᨨ犨ᆠᨨ 盐ᆠ� �ᆠ泐� �矄├ᆠᨨ �泐� 矄�   ᨨ ᨨ � ᨨᨨ犨ᆠᨨ 盐ᆠ� �ᆠ泐� ᨨ � �盐矄 ᨨ  ᆠ泐� 矄� ��泐ᆠ�ᆠ泐 盐᲼䰘桌 㡰 꾀ᨨ � �  ᆠ矄犨  犨ᨨᆠ泐� 矄 犨  ᆠ �  矄�泐�矄�� ᨨ �

ᆠ泐�  㡰 꾀ᨨ � �  ᆠ矄犨  犨ᨨᆠ泐� 矄 犨  ᆠ �  矄�泐�矄�� ᨨ ᨨ盐ᆠ泐�  ᆠ㡰 ᨨ ᨨ � �  ᆠ 矄 犨    犨ᨨ ᆠ泐� 矄犨  盐 � ᨨ鼀� ᆠ ��矄├ᨨ �   �矄ᨨ  ᆠ泐� 矄 㡰 ᨨᨨ � �  ᆠ矄犨  犨ᨨᆠ泐� 矄 犨  矄鼀ᆠ �  矄�泐�矄�� ᨨᨨ  ᆠ泐� 矄

WWW.JEEBOOKS.IN

EBD_8341 P-166







Integer Value Answer

� 꾀�ᆠᨨ 鼀矄矄҈kg ᆠ �҈C�矄� ��泐 矄꾀�鼀㦨 �ᆠᆠᨨ鼀矄盐  � 盐 ᆠ r ᨨ  ᆠ�ᆠ �  쟼  㡰㦨쟼矄�  w �ˆ犨 쟼㦨҈ ᔴ҈ w 㦨҈ 矄҈ᔴᨨ 矄�   ᆠᨨ ᨨ 泐  ᆠ�ᆠ ᨨᆠᨨ  �ᆠ   鼀 �鼀盐鼀矄  � 鼀矄҈�  泐 �ᆠ矄盐矄⼄盐 �鼀矄�矄 힘힘힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌 4 Fill in the Blanks  ᆠ�ᆠᨨ �V 泐ᨨ� xyz � 鼀矄㡰�

矄ᆠ�矄�� 泐V㦨xᨨ矄 ᆠ�ᆠ �   ᨨ�  ҈鼀鼀㡰�矄⏌鼀 ᲼҈黨黨㜠҈㝐├桌 䰘 ��盐矄 ᨨ犨矄� ᨨ ᆠᨨ 矄 ᨨ �� ��ᨨ � 犨 �ᆠ  ᆠ�ᆠ � �矄矄  盐矄ᨨ  ᨨ � 犨� � ᆠ├矄졠  ᨨ� 矄AB C 鼀� �盐  ᨨ  ᆠ�ᆠ � �矄�矄 ᨨ�  ᲼҈黨㜠㝐├矄桌 꾀 

  ҈  

҈

㡰 ␔� S҈ᆠᨨ矄 V҈㦨҈�V㦨 㡰 ␔� Sᆠᨨ矄 V҈㦨V㦨� ᆠ㡰 ␔� S҈ Sᆠᨨ矄  V҈ = V =  㡰 ␔� S҈ Sᆠᨨ矄  V҈ =  V  V =  V 꾀ᆠ �졔q�矄 �  ᆠ ᨨ  ᨨ� 矄x㦨xx㦨x x㦨�x x = ¥ ᨨ  x �矄 ᆠ �q�矄 �   ᆠ ᨨ  ᨨ� 矄x㦨xx㦨xx㦨x x = ¥  x�矄ᨨ矄��ᆠᨨ 矄  ├ ᆠ�ᆠᨨ � ᨨ�  盐ᨨᆠ �Q �矄 ᆠr ᨨ鼀�ᨨQ⏌ per㡰   ᨨ � ᨨ���  盐ᨨ ᨨ 矄泐矄鼀ᨨ ᆠ �矄�矄 ᲼҈黨黨和㜠㝐├矄桌 q ln q 㡰  㡰 pe x ln  ᆠ㡰 ¥ 㡰 pe x     꾀 矄ᨨ�  ᆠᨨ 盐ᆠ� � 矄  � �  ᆠ � Q �矄 矄盐ᨨ盐   泐  盐 ᆠ �  ᆠᨨ ᆠ �ᆠ ᆠᨨ 盐ᆠ� � ᨨᨨ犨矄 �ᆠ矄  ᨨ � �  ᆠ犨

 矄盐 ᆠᨨ  矄ᨨ� 矄   ᨨ  ᨨ盐矄盐 ᆠ ᨨ   ᨨᨨ犨矄 Vᔼ  矄 �矄 ᨨ犨�� ᆠ � ᨨ Q  犨ᨨ � �  ᆠ犨  矄鼀 ᲼҈黨黨㜠㝐├矄桌 犨ᨨ矄盐 ᆠ矄�矄 㡰 V 㡰 V ᆠ㡰 V 㡰 V 꾀 ᨨᨨ犨鼀矄 ᨨ  �盐矄�ᆠ鼀矄�矄ᆠ � 矄盐ᆠ   ᨨ �ᨨ �矄矄盐 ᆠ�矄҈ᨨ矄 ᨨ �  ᆠ ᨨ  矄 �矄 ᲼҈黨㜠҈㝐├桌 㡰 ᨨ 㡰 ҈ᨨ矄 ᆠ㡰 矄鼀矄ᨨ� �ᆠ鼀矄犨泐 ᨨ鼀 矄盐 ᆠ 㡰 矄鼀矄ᨨ� �ᆠ鼀矄犨泐 ᨨ鼀 矄盐 ᆠ

犨ᨨ�ᆠ�ᆠ盐 �矄ᆠ矄矄 泐 �矄 ᆠᨨ ҈鼀 ᆠᨨ

ᆠ  ᨨ 泐�  矄犨�ᆠ  矄矄 ᨨ犨  �    ��盐ᔴ � ᨨ� ᨨ矄ᨨ   矄�泐黨├�鼀矄  ᨨ盐� � 泐 ᨨ ᆠ ᨨ  ᨨ �矄ᆠ졠 ᆠ矄ᨨ鼀 ᨨ� ᨨ矄ᆠ �鼀� ᨨᆠ�泐 矄犨�ᆠ �矄ᆠᨨ矄 ᨨ 泐ᨨ�ᨨ ᆠᨨ矄矄  �矄ᆠ矄꾀矄矄盐 ᨨ� ᨨᨨ  �盐矄맔҈䰘鼀矄ᨨ矄鼀ᨨ� ��ᆠ泐  ᨨ矄 犨   �矄ᆠ矄  盐鼀ᨨ ᆠᨨ 矄矄 �  �矄 ᨨ� ᨨ �矄 힘힘힘힘힘힘힘힘 �ᆠ  盐ᨨ泐 ᆠ泐 ᨨᆠ ├ ᆠᆠ�ᨨ  盐ᨨ��泐㦨҈鼀矄  ᆠ �ᨨ  

ᆠᨨ  㡰㦨҈맔҈҈黨ᔴ㡰 ᲼꾀 桌

2

� 



꾀盐 � ᨨ鼀ᆠ�ᆠ � ᨨ� � �� ᨨ矄��x㜠 �ᆠ�ᨨ  �矄矄 � ��ᨨ A  ᨨ��� B  ᨨ� ᨨ  x㜠 �矄 x 㦨졔҈ᆠ鼀 C  ᨨ� ᨨ  y㜠 �矄y 㦨졔҈ᆠ鼀 

 ᨨ �矄 ᨨ� 矄AB  C 矄�矄 泐 ᲼҈和桌 㡰 VA VB 㡰 VA >VB ᆠ㡰 VA VC 㡰 VA >VC ᨨ ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐犨 �ᆠ ᨨ   ᨨᨨ犨� � 矄鼀 矄�矄盐䁸 ᲼҈黨黨黨㜠㝐├矄桌





҈黨

Physics

6 MCQs with One or More than One Correct Answer  犨ᨨ ᨨ 㜠ᆠᨨ 盐ᆠ� � 矄 矄 ᨨ   �� ҈     ᆠ泐� � 盐 � ᨨ鼀 ᨨ盐鼀 ᆠ �  矄��矄 졔r  r 矄ᆠ�泐ᆠ 矄盐ᆠ   泐�泐ᨨ 矄矄 ᨨ犨 �   ��盐꾀ᨨ� 矄�  ᨨ� � ��ᨨ

᲼꾀 ҈桌 r

–r 

҈

㡰 ᆠᨨ矄�ᆠ � �矄 ᨨ 㡰 ᆠᨨ矄�ᆠᨨ ��矄ᆠᨨ 矄  ᆠ㡰 ᆠᨨ矄�ᆠ � �矄ᆠᨨ 矄 � 鼀� �盐  㡰 ᆠᨨ矄�ᆠ �  矄矄鼀 �ᆠ�ᨨ

黨 和� ᨨ�  ᆠ �矄  ├    �ᆠ矄 ᨨ  �盐  �ᨨ ᨨ 矄�  ᆠ O矄矄 ᨨ犨 �   ��盐෌�

҈ q  犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 pe 0  㡰ᆠᨨᆠ䁸 ᲼҈桌

  K =

졔q



E–q P

Sw�tch

A 졔q

S

T

O

҈鼀

D –q



R B졔q

– qC

WWW.JEEBOOKS.IN

P-167

Electrostatic Potential and Capacitance



҈



㡰 ᆠ�ᆠ � O�矄⧤ᨨ �OD 㡰 ᨨ �O�矄 ᨨ ᆠ㡰 ᨨ �ᨨ� 矄ᨨ  � PR�矄矄鼀 㡰 ᨨ �ᨨ� 矄ᨨ  � ST�矄矄鼀 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄⏌ᆠᨨᆠ䁸᲼҈҈桌 㡰 ᔼ  ᆠ�ᆠ �  盐ᨨᨨ� ᆠ ��矄矄 � � 矄 ᨨ     ෌盐矄矄犨犨�矄��  㡰  ෌盐矄矄 犨 ᆠ   盐矄  ᨨ ᆠᆠ盐   � �矄�盐�ᨨ ᨨ盐  ᆠ�ᆠ �ᨨ ᆠ㡰 ᔼ  ᆠ�ᆠ � 犨 犨ᨨᨨ� ᆠ �矄�矄 ᨨ 矄ᨨ鼀犨    矄�� ᨨ  犨ᨨᆠ �矄�矄 矄鼀 㡰  犨ᨨ├ ᨨ  泐      ᨨᆠ �  鼀ᨨ� �  盐 � ᨨ矄�� ᆠ � ᨨ鼀 ᨨ�  꾀 ᨨ � 꾀 ᨨᨨ� ᨨ ��矄 - 꾀㡰 꾀矄 �ᆠ鼀矄 꾀ᨨ  �盐矄 꾀 矄ᨨ� 鼀 矄 ᨨ  �盐矄   꾀㡰├  ᆠ �矄 �� ᆠ ��졔턼ᨨ犨 泐ᆠᨨ

ᆠ 泐 � 鼀 犨� 

᲼҈҈桌 㡰 E �ns�de 㡰 턼꾀>턼 = A s A RB ᨨn surface ᨨn surface ᆠ㡰 = 㡰 E A < EB s B RA 꾀矄 �ᆠ矄泐鼀鼀�ᆠᆠ �矄泐矄鼀�矄ᆠ  ᨨ���  ෌� 쟼ᆠ�ᆠᨨ � ᲼和㜠�㝐├矄桌 Q Q V= r £ R 㡰 V = r > R 㡰 pe R per V

㡰 㡰 ᆠ㡰 㡰 





␔� � r㦨Rᨨ ᆠᨨ矄  ᆠ ��矄Q 쟼ᆠ�ᆠ � �矄 �矄ᆠᨨ � 盐 r㦨R ᔴ ��矄ᨨ 泐矄 r㦨R 쟼ᆠᨨ矄�ᆠ �泐�矄 ᨨ ᨨrR

9 Assertion and Reason Type Questions 和T꾀TE㝐ENT㜠҈ ᨨᆠ�ᆠ盐ᨨ矄矄  �矄 盐矄 矄  ᆠ ᨨᨨ �� ᆠ�ᆠᆠ�ᆠ盐�矄 

和T꾀TE㝐ENT㜠 ᆠ�ᆠᨨ �ᨨ 矄 ᨨ  �盐矄 犨� ᆠ �턼盐 � ᨨ鼀泐 �矄�盐 ᨨ  矄盐 ᆠ 턼 �矄�� 泐 pe 

᲼桌



㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐 10 Subjective Problems  꾀 ᆠᨨ 盐ᆠ� � �⼄盐�  盐 ᨨ  �盐矄     �ᆠ├ 矄矄 t ta㡰�矄ᆠ � ᨨᨨ �Vᔼ  盐ᆠᨨ矄矄 ᨨ ᨨ �  ᨨ �ᨨ   ᨨ ᲼�㜠㝐├矄桌 � 犨ᨨ �  ᆠ �矄Q Qᨨᆠ  ᨨ� 矄 犨� ᆠᨨᨨ � 矄 a㡰  졔a㡰矄ᆠ�泐�   x㜠y  ᲼҈黨黨҈㜠졔졔㝐├矄桌 㡰 和 ᨨ犨 ᨨ� 矄�  x㜠y 犨  ᆠ�ᆠ ᨨ � 盐ᨨ 犨ᨨᆠ �矄�矄 ᨨ�ᨨ ᆠ�ᆠ � �矄 �盐矄  ᨨᆠ�ᨨ ᨨ �矄ᆠ  㡰 ෌�  矄矄�ᨨ  V x㡰� ᨨ� ᨨ   x㜠 �矄 矄├ᆠ   盐 ᆠ�ᨨ V x㡰ᨨ  犨 ᨨx㜠  �矄 ᆠ㡰 ᔼ �ᆠᨨ ᆠ �졔q矄矄 ᨨ鼀矄 ᆠ  ᨨ  ᆠ�ᆠ 矄 ᨨ犨泐矄 ᨨ ⼄盐 ��盐鼀    �ᆠ 盐泐ᆠᨨ矄矄矄 ᆠ�ᆠ � �矄 矄 犨  � ᨨ矄矄ᨨ  ᆠᨨ ᆠ �ᆠ矄 �ᆠ鼀�ᆠ矄 矄AB Cᨨ  ��ab c abc㡰 矄盐 ᆠᆠ �  矄��矄 s   s   s 矄ᆠ�泐 ᲼҈黨黨㜠䰘㝐├矄桌 �㡰 �  ᨨ �ᨨ   矄 矄AB C ��㡰 ᔼ  矄 矄A C 矄鼀ᨨ �ᨨ�

 �ᨨ 犨   ��ab c 䰘 꾀ᆠ ��Q�矄 �矄�盐 ᨨ犨ᨨᆠᨨ ᆠ �ᆠ ᨨᨨ犨 矄 矄 ᨨ  �� �r  �R >r㡰 矄盐ᆠ      矄盐 ᆠ  矄��矄  ⼄盐 �    ᨨ �    ᆠᨨ鼀鼀ᨨ

ᆠ  ᲼҈黨҈㜠㝐├矄桌

Topic-2 : Electric Potential Energy and Work Done in Carrying a Charge 1 ҈

MCQs with One Correct Answer

㡰 � ᆠ矄泐

꾀犨ᨨᨨ� ᆠ �矄q q �  ᨨ  x㜠 �矄 d d � x = -   x =  矄ᆠ�泐ᔼ  � ᨨ� ᆠ �   �q�矄├  ᨨ鼀 ᨨ��� ᨨx = dᨨ � 矄鼀�ᆠ�ᆠ矄 矄 ᨨ犨 �   ��盐  �泐ᨨ  ᆠ �犨� [Main Sep.04, 2020 (I)] q

q  pe d

㡰 � ᆠ矄泐

q  pe d

q  q 㡰 ᆠ矄泐 pe d pe d 泐 ᨨ�  �ᨨ    矄� �泐�ᨨ �   �盐鼀 ᨨ鼀  ᆠᆠ  ᨨ鼀 矄  ᨨ盐�    矄鼀 ᨨ � �  ᆠ �ᨨᨨ  � 矄 矄ᨨ  泐 ᨨ�   �盐鼀 �ᨨ 矄�矄ᆠᨨ矄ᨨ ᲼㝐� 和 ᔼᔼ㡰桌 㡰 ҈ 㡰 ҈䰘 ᆠ㡰 ҈ 㡰 �䰘

ᆠ㡰 ᆠ矄泐



q

WWW.JEEBOOKS.IN

EBD_8341 P-168





Physics

꾀矄泐矄鼀ᨨ  ᆠ �矄ᆠ 矄矄 ᨨ犨 �   ��盐

ᔼ >>  ᨨ � �泐ᨨ  矄泐矄鼀�矄矄��

泐 ᲼㝐� 黨꾀�҈黨ᔼ桌  ҈ é - q - qQd ù ҈ é - q  qQd ù + ê ú 㡰 㡰  ê ú p Î ë d  D  û p Î ë d D û ҈ é q  qQd ù ҈ é q  qQd ù +  ú 㡰 -  ú ê+ ê ᆠ㡰 p Î ë d p Î ë d D û D û

ᆠ �矄턼졔⼄ 졔⼄ᆠ  �ᆠ矄ᨨ �� 㜠 ��矄ᨨ矄ᆠ矄� �矄矄 ᨨ犨 ᨨ犨   ᆠᨨ矄�ᆠ �泐ᨨ  ᆠᨨ ��盐�ᨨ �矄 ᨨ�  盐 ᨨ 턼�矄 ᲼㝐� ҈҈ ҈黨ᔼ桌 턼

졔⼄

졔⼄

-⼄ - ⼄ ᆠ㡰 㡰 ⼄ ҈+   +҈ ᨨ盐 ⼄盐 ᨨ�  ᆠ �矄턼ᆠ  ᆠ  �    泐   㡰 㡰  㡰  㡰 犨ᨨ├ ⼄盐�  ᨨ 盐  �   ᆠ � 턼    ᨨ���  ᨨ    ᆠᨨᨨ � 矄泐矄鼀 犨�  ᲼㝐�  ҈  ҈黨 ᔼᔼ桌 㡰 졔⼄

�

㡰

턼  pe 

㡰

҈ ö æ ç҈ + ÷ ø è

턼  pe 

㡰

턼 턼 㡰  pe    pe 和鼀 ҈ᨨ犨ᨨ├�矄⼄盐� ᨨ ᨨ ᨨ鼀ᨨ矄 ᆠ �犨  泐犨ᨨᨨ� 矄ᨨ  ⼄盐�ᨨ �矄盐 ᆠ 和鼀 쟼ᆠ�ᆠ� 矄ᨨ  ᨨᆠ ⼄盐�ᨨ � 矄盐 ᆠ矄鼀盐盐泐 �ᆠ盐ᨨᆠ ᨨ  ᲼㝐� 졠 � 꾀��҈桌 㡰 和鼀 ҈�矄盐和鼀 �矄盐和鼀 �矄  ᆠᨨᆠ  �ᨨ ᨨ 和鼀 ҈ 㡰 和鼀 ҈�矄盐和鼀 �矄盐和鼀 �矄

ᨨ ᆠᨨᆠ  �ᨨ ᨨ 和鼀 ҈ ᆠ㡰 和鼀 ҈�矄盐和鼀 �矄 矄 㡰 和鼀 ҈�矄 矄和鼀 �矄盐 ᔴᨨ 矄� 矄泐矄鼀ᨨ  ᆠ �矄q⏌ q⏌ q⏌ᆠ ᨨ� 矄 A, B C矄ᆠ�泐矄矄 ᨨ犨 �   ��盐

├Oᨨ ᆠ ᨨ  ᆠ�ᆠᨨ  �盐矄   � CAB㦨 ᲼桌

ᆠ㡰



䰘

҈ ö æ ç҈ + ÷ �ø è



 ᔴ  꾀





㡰 ᆠ�ᆠ � ᨨ� O�矄

q pe  R 

 �ᆠ ᨨ �

  �� 㜠 �矄 㡰 ᨨ � �泐ᨨ  矄泐矄鼀�矄 ᨨ ᆠ㡰 鼀� �盐 ᨨ   ᨨᆠ犨  ᆠ �矄C  B�矄

q �pe  R 

q ҈pe R  ᨨ矄��  ��ᨨ� ᆠ �矄ᨨ ⼄盐鼀� �盐  aö æ -a ö æ  ├  çè   ÷ø   ç   ÷  矄ᆠ�泐   è ø 犨ᨨ├ ᨨ 泐 ᆠ�ᆠ � 犨   ᨨ ᨨ矄��ᨨ�  ᆠ ��矄鼀ᨨ  ᨨ鼀 a㡰ᨨ a㡰�矄 ᲼䰘桌 㡰 ᨨ矄�� 㡰 �� ᆠ㡰 ᨨ 㡰  矄ᨨ   ᆠᨨ

ᆠ� � � ��  �  ᨨ矄��ᨨ 矄 黨

犨ᨨ⼄盐ᨨ� ᆠ �矄 �  x㦨a x㦨졔aᨨ

 x㜠 �矄꾀 ᨨ ᨨ� ᆠ �Q�矄ᆠ  ᨨ��� 

ᆠ  ��  ᆠ�ᆠᨨ � �泐ᨨ Q犨  � �矄 �矄ᆠ  泐 矄鼀 �矄 ᆠ x ᨨ �  x㜠 �矄 �矄 ᨨ �鼀泐ᨨᨨ�ᨨ ᨨ ᲼和桌 㡰 x 㡰 x  ᆠ㡰 x  㡰 ҈⏌x ҈ ᆠ �矄Q졔q 졔qᆠ  �ᆠ矄ᨨ  �� 㜠 �  �矄ᨨ矄ᆠ矄 � � 矄 矄 ᨨ犨    ᆠᨨ矄�ᆠ �泐ᨨ  ᆠᨨ ��盐�ᨨ �矄 ᨨ� Q �矄 ᲼和桌 ⼄盐ᨨ -q 㡰 Q ҈+  -q 㡰 +  +q +q ᆠ㡰 q a 㡰 졔q ҈҈ 犨ᨨᨨ� ᆠ �矄졔q q   �   dᨨ㡰 dᨨ㡰矄ᆠ�泐ᨨ ax㜠yᆠᨨᨨ � 矄泐矄鼀  ᲼҈黨黨�和桌 㡰 ᆠ�ᆠ � Eᨨ� 矄ᨨ  x㜠 �矄 矄  矄鼀 �ᆠ�ᨨ

㡰 쟼ᆠ�ᆠ � ᨨ� 矄ᨨ y㜠 �矄�矄ᨨ �x㜠 �矄 ᆠ㡰 ␔ᨨ├ 矄ᨨ ᨨ � � �� �矄ᆠ � ᨨ鼀 ¥ ᨨ ᨨ���

㡰  �ᨨ鼀ᨨ鼀 �矄qdᨨ � x㜠 �矄 ҈ 犨ᨨ �  �ᆠ  �  � �矄 ᆠ  ᨨ   �盐矄 R 鼀矄 

㡰 ᨨ �ᨨ� O�矄

ᆠᨨ �泐ᆠ  �矄 ᆠR鼀矄ᔼ  Q҈ ᆠᨨ盐ᨨ鼀   Q ᆠᨨ盐ᨨ鼀矄ᆠ�泐 ᆠ �矄盐 � ᨨ鼀泐 矄 ᨨ  犨ᨨ� �矄 犨ᨨ├ ᨨ � 鼀ᨨ� �ᆠ � q ᨨ鼀 ᆠ ᨨ ᨨ � �ᨨ ᨨ  ᨨ �矄 ᲼҈黨黨㜠㝐├矄桌 q Q҈ 㜠 Q 㡰  㜠҈㡰 㡰 ᨨ 㡰  pe  R 㡰 ᆠ㡰

q  Q҈ + Q 㡰 pe R㡰



q Q҈ + Q 㡰  + ҈㡰  pe  R 㡰

WWW.JEEBOOKS.IN

P-169

Electrostatic Potential and Capacitance

҈

꾀ᨨ� ᆠ �qᨨ 鼀矄矄m�矄矄盐矄  �ᆠ泐泐 r 矄� �ᨨ  � l꾀ᨨ�  �ᨨᨨ  �ᨨ鼀ᨨ鼀  p �矄

ᨨ犨ᨨ盐� ᨨ犨 矄q ᨨ鼀� � �泐矄ᨨ  ᆠ � 鼀ᨨ矄犨泐  � ⼄盐���盐鼀ᨨ矄��ᨨ ᨨ  矄泐矄鼀 � ᆠ盐 � �   �ᆠ�ᨨ  ᨨ   �ᨨ   �矄  �矄 ᆠ矄�矄矄 ᨨ犨 �   ��盐ᨨ犨ᔼ  犨ᨨ├ ᨨ �

� �� �  �ᨨᨨ �矄ᨨ矄��ᨨ �矄N 맔 mgh㡰犨 ��矄   ᆠᆠ�ᨨ  盐 ᨨ ��泐      盐 ᨨ  N �矄 힘힘힘힘힘힘힘힘힘 ᨨ  ᨨ ᆠᨨ  ᨨᆠ矄├� � F �矄 矄鼀 ᨨ ᨨᆠ矄 矄� q 犨 F�矄 泐ᨨ ᨨ   ᨨᆠ矄 q�矄  �犨

 ᨨ 犨ᨨ ᨨᆠ矄㡰 ᲼꾀 桌

ᨨ� 鼀矄矄� ⼄盐���盐鼀

҈� ᔴ �矄졔q qᨨᆠ  ᆠᨨ 矄ᨨ ᆠ盐ᨨ 矄� 矄矄 ᨨ犨�   ��盐 �  犨ᨨ├ ᨨ ᨨ矄  ᆠ �矄ᨨ� � � �矄 ᆠ ᲼㜠㝐├矄桌 –q +q

–q

+q –q

+q

҈ 꾀ᆠ�ᆠ盐� �ᨨ  �盐矄R犨� 盐 � ᨨ鼀ᨨ矄��ᆠ �  矄�泐l盐 � � �矄ᨨᆠ �  y㜠z 犨� �矄 ᆠ  ᨨ��� O꾀�ᆠᨨ 鼀矄矄m ᨨ矄�� ᆠ �q�矄ᨨᆠ  ᨨ鼀 ᨨ� P R   㡰 ᨨ  

a

l l a

l矄� 

q

h

p

ᨨ矄��x㜠 �矄 �ᆠ泐ᨨ犨 矄O犨�  � ��矄 v �   矄鼀矄 ᨨ 㜠 ᨨ㡰盐 ᨨ  矄  矄盐ᆠ   �ᆠ ᨨ矄 ᨨ盐 ᨨP ᲼҈黨黨㜠㝐├矄桌 ҈䰘 犨ᨨ �  ⼄盐ᨨ矄��ᆠ �矄ᆠ ᨨ 鼀� �盐 �맔 10�ᆠᨨ盐ᨨᆠ ᨨ� 矄A B矄 泐 �矄 ᆠ ᨨ  鼀 꾀  ⼄盐   ᨨᨨ矄� ᆠ � 鼀ᨨ矄 ᨨ犨 矄  鼀 ᨨ �   �  COD    �ᆠ盐 �矄ᆠᨨᨨ  � AB ᲼҈黨�㜠㝐├矄桌 꾀

10 Subjective Problems ҈

+q –q

졔⼄

⼄



꾀ᆠ �졔Q�矄 �   ᨨ��� ᨨ  ᆠᨨ㜠ᨨ � 矄泐矄鼀 uur 犨 �矄鼀ᆠ�ᆠ �ᨨᨨ  �ᨨ鼀ᨨ鼀  p ᨨ� � � 犨泐 ᨨ鼀 ᆠ �ᨨ � x㜠 �矄�矄矄  ᨨ鼀 ᨨ�  犨泐 ᨨ鼀 ᨨ���  ᲼㜠㝐├矄桌 㡰 ᔴᆠ盐 ⧤쟼ᨨ   �ᨨ犨  �ᆠ 矄ᨨ ᨨ�  d㡰 㡰 ᔴᆠ盐  ᨨᆠᨨ  ᆠ �졔Q �矄鼀ᨨ鼀 



ᔴ  졔⼄

 鼀ᨨ� � ᆠ � 犨   � ᆠ 矄   ᨨ�  C   �矄 ᆠᨨ 鼀 ᨨ鼀O 矄├� �ᆠ �泐ᨨ ᨨ盐矄 ᔴᆠ盐  �矄 ᆠᨨ    矄ᨨ� D犨 �ᆠ  

��ᆠ �犨�ᆠ  ᨨ盐 � �ᨨ犨 矄C

Topic-3 : Capacitors, Grouping of Capacitors and Energy Stored in a Capacitor 1 ҈



MCQs with One Correct Answer

犨ᨨᆠᆠ�ᨨ矄ᨨ ᆠᆠ� ᆠ矄ᔴ ᔴᆠ � ᨨᨨ㜠  � �  ᆠ矄  矄ᆠ�泐 矄  

ᆠᨨ

ᆠ � � 矄盐ᆠ 鼀

  ᨨ矄��鼀�㜠

ᨨ ᨨ �矄ᆠᨨ

ᆠ ᨨ  ��鼀� ᨨ  ᨨ 

 �  �泐ᨨ  �矄ᆠᨨ ��盐�ᨨ �矄 ᲼㝐� 和� ᔼ㡰桌 �   黨  㡰 ᔴ 㡰 ᔴ ᆠ㡰 ᨨ 㡰 ᔴ    ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 ᆠ �ᨨ  �m ᆠᆠ�ᨨ�矄 ᲼㝐� 和� ᔼᔼ㡰桌  m

 m





꾀ᆠᆠ�ᨨ C �矄 盐泐ᆠ �  犨�  ᨨ� V  꾀  �矄ᆠᨨ

ᆠ� � ᨨ�矄ᨨ盐ᆠ��矄ᆠᨨ

ᆠ �  C 犨�  ᨨ 盐 ᆠ � ᆠᆠ�ᨨᨨ ᆠᆠ� ᆠ      �泐ᨨ矄矄�  ᨨᆠ矄矄  ᆠ ��矄 �矄�盐 犨  犨ᨨᆠᆠ�ᨨ矄�矄 ᲼㝐� 和 ᔼᔼ㡰桌 ҈ ҈ ҈ ҈  CV 㡰 㡰 CV CV 㡰 CV ᆠ㡰     ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐 ᨨᆠ ��矄䰘�mᔴ     ᨨ�ᆠᨨ矄矄 ᆠᆠ�ᨨ C �矄     ᆠ �ᨨ ᆠᆠ�ᨨC�矄 [Main Sep. 03, 2020 (I)]

C㦨m

� m

졔 

O







㡰 ҈mᔴ 㡰 ҈黨mᔴ ᆠ㡰 ҈mᔴ 㡰 ��mᔴ

C

C҈㦨҈�m

㡰 �mᔴ

㡰 �黨mᔴ ᆠ㡰 ҈mᔴ

㡰 �mᔴ

WWW.JEEBOOKS.IN

EBD_8341 P-170

�



䰘



黨

Physics

꾀҈m ᆠᆠ�ᨨ�矄 盐泐ᆠ � ᨨᨨ � �  ᆠ ᨨ �꾀 鼀ᨨ� � 矄ᨨ盐ᆠᨨ���矄ᆠᨨ

ᆠ ᨨ 盐 ᆠ � ᆠᆠ�ᨨ� ᨨ犨 ᨨ � �  ᆠᆠᨨ矄矄 鼀ᆠᨨ鼀矄 ᆠᆠ� ᆠᨨ  矄ᆠᨨ ᆠᆠ�ᨨ�矄 [Main Sep.02, 2020 (II)] 㡰 ҈m 㡰 ҈�m 㡰 m ᆠ㡰 m 쟼 ᆠ� ᆠᆠ� ᆠ ᨨ   ᆠᨨ鼀� �ᨨ  ᨨ  犨ᨨ ᆠᆠ�ᨨ矄C҈ C�矄҈m ␔   矄ᆠᆠ�ᨨ矄 � �� 盐泐ᆠᨨ

ᆠ  ᨨ ᨨ� 矄ᨨ盐ᆠᨨ  ҈    �泐矄ᨨ �  ᆠᆠ�ᨨC�矄�鼀矄 ᨨ C҈ᔼ  矄ᆠᆠ�ᨨ矄ᆠᨨ

ᆠ � 矄�矄 � ᆠ� ᆠᆠ� ᆠ犨� ᲼㝐�  ᔼ桌 㡰 m 㡰 m ᆠ㡰 ҈m 㡰 m 꾀ᆠᆠ�ᨨ 矄矄ᨨ 꾀矄 泐 �矄 ᆠ�d犨  鼀ᔼ�矄 � 犨�  �ᆠ�ᆠ 犨 �ᆠ  矄 �ᆠ�ᆠᆠᨨ 矄  �矄矄k x㡰㦨K ҈졔 ax㡰犨 �x�矄  �矄 ᆠ鼀矄盐  ᨨ鼀ᨨ ᨨ   矄ᔼ  ad㡰 ᨨᆠᆠ� ᆠᨨ  矄泐矄鼀�矄 矄�� 泐  矄矄�ᨨ  ᲼㝐� 䰘 ᔼ桌 AK Î æ ad ö 㡰 ç҈ + ÷  ø d è  A Î K æ æ ad ö ö ç҈ + ç 㡰 ÷ ÷ d ç è  ø ÷ è ø æ  ö A Î K ç a d ÷ ҈+ ᆠ㡰  ÷ d ç è ø AK Î (҈ + ad ) 㡰 d

ᆠᨨ鼀� �ᨨ ᨨ 犨ᨨ� �  ᆠᆠ�ᨨ矄 ᨨ  ᆠᆠ� ᆠ ᔴ   nᔴ �矄 ᆠᨨ

ᆠ ᨨ  泐ᨨ  ᨨ�  ␔     ᆠᆠ�ᨨ矄  盐泐 ᆠ �  泐�矄鼀ᨨ     �ᆠ�ᆠ 鼀�ᨨ  �ᆠ�ᆠᆠᨨ 矄 ⧤�矄ᆠ 犨   犨ᨨ 矄 ᨨ    �矄 ᆠᆠ�ᨨ  犨 ᨨ � �  ᆠᨨ  ᆠᨨ鼀�  矄泐矄鼀�矄 ᲼㝐� 黨꾀�ᔼᔼ桌 n + ҈㡰   n 㡰 㡰  ᆠ㡰 㡰 ⧤ + n㡰 ⧤졔n ⧤졔n ᔼ  �� ᆠ�ᆠ盐� ᆠ �ᨨ m ᆠᆠ�ᨨ犨� ᲼㝐� ҈ 꾀� ҈黨 ᔼᔼ桌 㡰 �mᔴ

҈҈ 꾀ᆠᆠ�ᨨ犨� ᆠᆠ� ᆠ�m �矄ᆠ � ᨨ�mᔴᔼ  矄盐 ᨨ 盐ᆠ ᆠᆠ� ᆠᨨ   ᨨ犨鼀盐ᆠ 犨ᨨ├�矄 ᨨ 䁸 ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰 �맔҈ 㡰 䰘�맔҈  ᆠ㡰 ҈맔҈  㡰 ��맔҈ ҈ 꾀ᆠᆠ�ᨨ 矄҈m ᆠᆠ� ᆠ졠 ᨨ �矄 犨ᨨ矄�矄�� 졔 mᔴᆠ �   ᨨ   졔mᔴᆠ � ᨨ � �  ᆠ ᨨ ᆠᨨ矄矄  ᆠᆠ�ᨨ�矄 ᲼㝐� 꾀�҈黨ᔼᔼ桌 㡰  㡰 ҈ ᆠ㡰 � 㡰  ҈ ᔼ   ��盐矄 ᨨ犨   矄犨�ᆠ �和�矄盐   ᨨ鼀 ᨨ矄��ᨨ �꾀ᨨᨨ矄��ᨨ �  �泐 �矄矄� �   ᆠ�ᆠ盐�� 鼀矄ᨨ ᆠᆠ� ᆠ�ᔴ ᨨᆠ ��턼�矄 ᲼㝐�  ҈   ҈黨 ᔼ桌 꾀



和 e



ᔴ

҈ 턼  턼 � 턼  턼 㡰 ᆠ㡰 㡰  ᔴ  ᔴ  ᔴ  ᔴ ҈ 꾀ᆠᆠ�ᨨ犨� 矄ᨨ ҈鼀ᆠ  矄�ᨨ ᨨ ҈鼀ᔼ  ᆠ�ᆠ � 犨   矄�矄҈⏌ᔴ 鼀� �盐 ᨨ ᆠ �ᨨ ᆠ �矄 ᔴ ҈ ├Î0㦨�맔҈    㝐  㡰᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 䰘�맔҈҈ᔴ 㡰 �맔҈҈ᔴ ҈ ᆠ㡰 �맔҈ ᔴ 㡰 黨�맔҈҈ᔴ ҈� ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨  � ᔴ�   ᆠ�ᆠᆠ� ᆠᨨ  犨 ᨨᆠ�ᆠ盐��矄ᨨ�Ҙ 꾀盐矄�  ᆠ�ᆠ盐� � Ҙ  ᲼㝐� ҈ ҈黨ᔼᔼ桌 ᔴ  㡰







҈ 

㡰 黨mᔴ





ᆠ㡰 ҈mᔴ 㡰 mᔴ ҈



��盐 矄 ᨨ犨矄 ᆠ � ⼄㡰 矄盐矄 ᨨ� 㡰 �  ᨨ 矄�矄 ᆠᨨ鼀� �ᨨ ᨨ 犨ᨨ�� ᆠᆠ�ᨨ矄

ᆠᆠ� ᆠ矄 ᲼㝐� ҈꾀�҈黨ᔼ桌

䰘  䰘 Ҙ 㡰 Ҙ ᆠ㡰 Ҙ 㡰 Ҙ ҈҈ � ҈ ҈ ᔼ   ��盐矄 ᨨ犨 ᨨ犨 ᆠ �ᨨ   ᨨ  ҈m ᆠᆠ�ᨨ�矄mᔴ ᆠ �ᨨ  ��  ᨨ  m ᆠᆠ�ᨨ�矄 ᲼㝐� ҈҈ ҈黨ᔼ桌

㡰

 m ҈ m  m

㡰 m  ҈m ᆠ㡰 �m  m

㡰 m  m 㡰 m  m

 m

㡰 ҈ m ᔴ 㡰 졔҈m ᔴ ᆠ㡰 ҈m ᔴ 㡰 졔҈m ᔴ

WWW.JEEBOOKS.IN

P-171

Electrostatic Potential and Capacitance

҈䰘

҈

꾀 ᆠᆠ�ᨨ � � ᆠᆠ� ᆠ҈ �矄 ᆠ � 泐  泐 ᨨ  ᨨ �  �  ᆠ ᨨ ҈  犨  �矄 矄  ᆠ �� � 泐 �矄 ᨨ犨 �矄ᆠᨨ

ᆠ  ᨨᆠ� 矄ᨨ  �ᆠ�ᆠᆠᨨ 矄  ��矄矄� 犨  矄 犨ᨨ├ ᨨ 泐  ᆠᆠ�ᨨ ᨨ    矄�矄 ᲼㝐�  ҈   ҈黨 ᔼᔼ桌 㡰 黨 㡰 � ᆠ㡰 � 㡰  꾀   ᆠᆠ�ᨨ �矄 ᨨ    ᆠ鼀   矄�ᨨ 鼀鼀 ��矄 � 犨�   �ᆠ�ᆠ 鼀�矄ᨨ ⼄盐 �ᆠ├ 矄矄 矄 ��盐㡰犨�  �ᆠ�ᆠ ᆠᨨ 矄 矄⧤҈㦨҈⧤㦨҈ ⧤㦨҈ 㡰  �ᆠ�ᆠ ᆠᨨ 矄  ᨨ   鼀� 犨 �ᆠ  犨   盐泐 � 矄  �

ᨨ ᆠᆠ�ᨨ ��矄 矄鼀 ᆠᆠ� ᆠ 犨ᨨ盐   ᲼㝐�  ҈   ҈黨 ᔼ桌

æ ᔴ ö ç e = � ´҈-҈ ÷ ç 鼀  ÷ø è 㡰 ҈� 㡰 ҈ ᆠ㡰 � 㡰   꾀ᆠᆠ� ᆠᨨ m �矄⼄盐� �  ᆠ�ᆠᆠ�ᆠ盐� ᆠᨨ矄矄ᨨ � �  ᆠᨨ ҈├꾀� 盐鼀ᨨ ҈m ᆠᆠ�ᨨ矄  � 犨 �ᆠ  ᆠ  犨� 矄   ᨨ � �  ᆠᨨ  ᨨ鼀ᨨ   鼀� �鼀盐鼀

盐鼀ᨨ ᆠᆠ�ᨨ矄⼄盐� ᨨᆠ � �矄�矄 ᲼㝐� ҈䰘桌 㡰  㡰  ᆠ㡰  㡰 ҈  꾀ᆠᨨ鼀� �ᨨ  ᨨ  ᆠᆠ�ᨨ矄�矄矄 盐矄 矄 ᨨ犨  �    ��盐 鼀� �盐 ᨨ  ᆠ�ᆠ �  盐ᨨᨨ�  ᆠ �턼 � �ᆠ �⼄盐ᨨ 矄盐鼀ᨨ  ᆠ �矄 ᨨ  m  黨m ᆠᆠ�ᨨ矄㡰ᨨ�  �矄 ᆠ鼀 ᨨ鼀�犨ᨨ盐 ⼄盐 ᲼㝐� ҈桌 m

҈黨

m

㡰  㡰 ҈ ᆠ㡰 ҈ 㡰  꾀ᆠᆠ�ᨨ�矄鼀 ᨨ 犨ᨨ矄⼄盐矄ᨨ 矄�  � 矄  泐  �矄 ᆠ  㡰  ᨨ犨 � �盐ᨨ�ᨨ �矄 � 犨�  �ᆠ�ᆠᨨ  �ᆠ�ᆠ ᆠᨨ 矄 ⧤矄矄 ᨨ犨 �   ��盐ᔴᆠ� ᆠᨨ  �矄 ᆠᆠ�ᨨ�矄 ᲼㝐� 黨 ҈黨ᔼ桌

黨m m 졔 



⧤ Î  㡰  ⧤ + ҈㡰





⧤ Î   ᔼ ⧤ 㡰 ⧤  ҈㡰

⧤ Î  ҈ ⧤ Î  ᔼ ⧤ 㡰 ᆠ㡰   꾀ᆠᆠ�ᨨᨨ ᆠᆠ� ᆠ黨 �矄ᆠᨨ

ᆠ ᨨ泐ᨨ 鼀 ᔼ  �ᆠ�ᆠ鼀�ᨨ  �ᆠ�ᆠ � ᆠᨨ 矄  k 㦨 �矄 � 矄  犨    矄    鼀� �盐 ᨨ  � 盐ᆠ ᆠ �犨� ᲼㝐� ҈桌 㡰 ҈ ᔴ 㡰  ᔴ ᆠ㡰  ᔴ 㡰 黨 ᔴ ҈ ᔼ   ᨨᨨ犨� �ᆠ�ᆠ盐� 矄犨�ᆠ 和�矄ᆠᨨ矄 㦨  ᆠ �ᨨ  ᆠᆠ�ᨨᔴ҈矄 盐 ᆠ�ᨨ ᨨ �鼀犨� æ ᔴᔴ ö �� 泐 ç ᔴ⼄ = ҈  ÷  ᔴ҈ + ᔴ ø è ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ᔴ⼄쟼᲼҈  ⏌ ᔴ⼄㡰桌 ᔴ ᔴ҈ 㡰 ᔴ҈쟼᲼҈   ⏌ᔴ҈㡰桌







㡰 ᔴ⼄쟼  ⏌ ᔴ⼄㡰 쟼 꾀ᆠᆠ�ᨨ犨� ᆠ鼀 矄�ᨨ

犨  矄҈�ᆠ鼀�矄ᆠᨨ

ᆠ ᆠᨨ矄矄泐ᨨ 鼀 ᔼ   ᨨᆠᨨ ᆠ�ᨨ 犨  矄�矄�맔 ҈ 盐ᨨ �矄ᨨ �鼀泐 ᲼㝐� 졠 � 꾀�҈�҈桌

҈







ᆠ㡰 ᔴ쟼᲼҈  ⏌ ᔴ㡰桌

㡰 ⏌ᔴ 㡰 ⏌ᔴ ᆠ㡰 ⏌ᔴ 㡰 ⏌ᔴ � ��盐矄 ᨨ犨矄 犨ᨨ├ᨨ ᆠᆠ�ᨨ矄犨   盐鼀矄 � �ᆠ矄 ᆠᆠ� ᆠ矄 �  鼀�ᆠᨨ    盐 ᨨ ᆠᆠ� ᆠᔴ�  ⼄盐� ᆠᆠ� ᆠ犨 ᨨ�  꾀 �矄ᨨ҈m �矄 ᲼㝐� 졠 � 꾀�҈҈桌





҈









�



 ҈   m 㡰 m ᆠ㡰 m 㡰 m 㡰    

ᆠᆠ�ᨨ矄ᆠ ᨨ m ᨨᆠᨨ

ᆠ � 矄盐ᆠ 犨泐   ᆠ�ᆠᆠ� ᆠ�矄m  �矄ᆠ  ᨨ 泐ᆠᨨ

ᆠ� � 鼀 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 � 矄�矄 㡰 �  ᆠ㡰 犨ᨨ�  ᨨ � 矄�矄 㡰 犨ᨨ� 矄�矄 ᨨ �  ᔼ    ��  ᆠ�ᆠ盐� ᆠ � 턼 ᨨ    Ҙ  ᆠᆠ�ᨨ ᆠ  �矄矄ᔴ�矄�  ᨨ鼀҈Ҙ ᨨҘ 턼矄 盐 ᆠ�ᨨ ᨨ ἘᔴἘ�矄�� ᨨ泐泐 f�gures are drawn schemat�cally and are nᨨt tᨨ scale㡰 ᲼㝐� ҈�桌 ҈Ҙ







WWW.JEEBOOKS.IN

EBD_8341 P-172

Physics ᔴ �

ᔴ �

턼

턼

㡰

㡰 ҈Ҙ

Ҙ



҈Ҙ



ᔴ �

ᔴ �

턼

턼

ᆠ㡰

㡰 ҈Ҙ

䰘

Ҙ

Ҙ



҈Ҙ

Ҙ



ᔼ  ��盐  矄泐矄鼀 ᨨ  ᨨ盐 ᆠᆠ�ᨨ矄 ᆠᨨ

ᆠ  ᆠᨨ矄矄  ҈  泐 �矄 矄 ᨨ犨  ᔴ �   犨�  ᨨ犨  ᨨ鼀 矄犨�ᆠ  和 犨   � �矄ᆠᨨ矄  �矄 ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 m  m

和 m  m



黨



҈ 㡰 �Ҙᔴ ᨨ鼀ᨨ 㡰  Ҙᔴ ᨨ鼀 ᨨ ᆠ㡰 ᨨ 㡰 �Ҙᔴ ᨨ鼀ᨨ 꾀ᆠᆠ�ᨨ�矄鼀 ᨨ 犨ᨨᆠ�ᆠ盐矄 矄 泐 �矄 ᆠ �鼀鼀   犨�   �ᆠ�ᆠᨨ �ᆠ�ᆠᆠᨨ 矄 犨  鼀␔   ᆠ�ᆠ � �   �ᆠ�ᆠ�矄  ´ ҈  鼀  ᆠ �  矄�泐ᨨ  ᨨ矄��犨�ᆠᨨ矄ᨨ ᲼㝐� ҈桌 䰘  䰘 㡰  ´ ҈ ᔴ 鼀 㡰  ´҈ ᔴ 鼀 ᆠ㡰  ´҈ ᔴ 鼀  㡰  ´҈ ᔴ 鼀  꾀ᆠᆠ�ᨨ � �矄�ᨨ 犨   矄 꾀 鼀�犨�  �ᆠ�ᆠᆠᨨ 矄  ⧤ 矄ᆠᆠ� ᆠᔴᨨ犨ᨨ 㜠 � ᨨ  鼀��矄 ᆠ 泐 ᨨ 鼀�犨�  �ᆠ�ᆠᆠᨨ 矄 ⧤ 矄ᨨ  ᆠ�泐 犨ᨨᆠᆠ�ᨨ矄ᨨ 犨�  ҈  꾀 �ᆠ�ᆠᆠᨨ 矄 ⧤  ᨨ 犨�  꾀 꾀     �ᆠ�ᆠᆠᨨ 矄 ⧤ᔼ  ᆠᆠ� ᆠᨨ  �矄 犨 ᔴ ᆠᆠ�ᨨ�矄ᔴ   �矄 ᲼㝐� 졠 � 꾀��҈桌 ᔴ   ҈ 㡰 ҈ 㡰 ᆠ㡰 㡰    ᔼ  �� ᆠ�ᆠ盐�ᆠ �ᨨ 졔mC�矄�� ᨨ 盐 ᨨ   mF ᆠᆠ�ᨨ   �    矄 泐矄   ᆠ �ᨨ  盐ᨨ  mFᆠᆠ�ᨨ�矄 ᲼҈桌 㡰 졔mᔴ

҈ 꾀m ᆠᆠ�ᨨ�矄ᆠ � 矄矄 ᨨ犨 �   ��盐  ᆠ �ᨨ �矄矄ᨨ  �泐 �矄矄�   矄犨�ᆠ 和�矄盐  ᨨᨨ矄��ᨨ �矄 ᲼҈҈桌 㡰 奠 㡰 奠 ᆠ㡰 䰘�奠 㡰 奠  꾀ᆠᆠ�ᨨC 犨� 矄ᨨ 盐 � 矄�ᨨ  �矄 � 犨� �⼄盐� ᨨ  �ᆠ�ᆠᆠᨨ 矄 K 㦨 ᨨ �⼄盐� �矄d⏌� ��泐和盐ᨨ矄 �⼄盐�  ᆠ矄矄ᆠᨨ 矄 矄 v �鼀ᆠᨨ 矄 矄  盐 ᆠ�ᨨ ᨨ �鼀�矄 ᲼桌 e  R 㡰 �d + vt ҈�d + 黨vt 㡰 e  R C  㡰 d  - dvt - 黨v t  d R d⏌  e R ᆠ㡰 �d - vt ҈�d - 黨vt 㡰 e  R 㡰 d  - dvt - 黨v t   犨ᨨ�  �ᆠᆠᆠ�ᨨ矄  矄鼀ᆠᆠ� ᆠC 졠 ᨨ  鼀�矄ᆠ � ᨨᨨ �V҈  ᨨ V

 ��  矄 ᨨ    ᆠᆠ�ᨨ矄  ᆠᨨ

ᆠ ᨨ� ␔   ᨨ矄�� 矄矄ᨨᆠᨨ

ᆠ   ᆠ矄�  �泐ᨨ  ᆠᨨ鼀�  矄泐矄鼀�矄 ᲼和桌 ҈ ҈ C V҈ - V C V҈ + V 㡰 㡰     ҈ ҈ C V҈ - V C V҈ + V 㡰 ᆠ㡰    ᔴᨨ 矄�  矄�盐�ᨨ 矄 ᨨ犨 �   ��盐 ᆠᆠ�ᨨ A 矄ᆠ �q ᨨ �犨 矄B �矄盐 ᆠ �  ᆠ � � �ᨨ  ᆠᆠ�ᨨB ᨨ ��鼀  矄犨�ᆠ �矄 ᆠᨨ矄 �矄 ᲼҈和桌 ⼄

( (

) )

졔 졔 졔 졔 졔 졔

( (

) )

和

꾀



㡰 ᨨ 㡰 q⏌ ᆠ㡰 q 㡰 q � 꾀ᆠᆠ�ᨨᨨ A矄�ᨨ d ᆠᆠ� ᆠ C �矄 �  犨�    �   �ᆠ�ᆠ 鼀�矄 � � �ᆠ�ᆠ ᆠᨨ 矄 矄 k ҈ k    k  矄 矄 ᨨ犨 ᔼ 矄� � �ᆠ�ᆠ鼀��矄ᨨ盐矄 ᨨ   矄鼀ᆠᆠ� ᆠC�  �矄ᆠᆠ�ᨨ  �矄 �ᆠ�ᆠ ᆠᨨ 矄 k�矄�� 泐 ᲼和桌 A⏌

A⏌



K

d⏌

d K

A

㡰 졔mᔴ ᆠ㡰 졔mᔴ 㡰 졔mᔴ

҈ ҈ ҈ 㡰 ҈ = ҈ + ҈ + ҈ 㡰 = + + K K K K  K K҈ K   K ҈   K҈ K  ᆠ㡰 K = + K 㡰 K㦨K҈졔K졔K K҈ + K 

WWW.JEEBOOKS.IN

P-173

Electrostatic Potential and Capacitance



䰘



黨

犨ᨨ�  �ᆠ鼀矄�� ᨨ矄��ᆠ �矄Q҈  Q Q҈㡰矄ᆠ�泐ᔼ  泐 ᨨ犨ᨨ盐� ᆠᨨ矄 ᨨ� ᨨ ᨨ鼀ᆠᆠ�ᨨ犨� ᆠᆠ� ᆠ C ᨨ � �  ᆠ犨  鼀�矄 ᲼҈黨黨黨㜠㝐├矄桌 㡰 Q҈졔Q㡰⏌ C㡰 㡰 Q҈졔Q㡰⏌C ᆠ㡰 Q҈Q㡰⏌C 㡰 Q҈Q㡰⏌ C㡰 꾀ᆠᆠ�ᨨᨨ ᆠᆠ� ᆠC�矄ᆠᨨ

ᆠ ᨨ 泐 �矄ᆠ � ᨨᨨ � �  ᆠV꾀 ᨨ  ᆠᆠ�ᨨ ᨨ  ᆠᆠ� ᆠ C �矄 矄�鼀�泐 ᆠ � ᨨ  ᨨ � �  ᆠ V  ᆠ �� � 泐�矄 ᨨ犨 �矄ᆠᨨ

ᆠ   ᆠᆠ�ᨨ矄ᆠᨨ

ᆠ �  ᨨᆠ ᨨ � 矄盐ᆠ 犨泐  ᨨ矄��鼀� ᨨ ᨨ �矄ᆠᨨ

ᆠ ᨨ  ��鼀� ᨨ  ᨨ   �  �泐ᨨ  ᆠᨨ ��盐�ᨨ �矄 ᲼҈黨黨�和桌  � 黨  CV  㡰 CV  㡰 ᨨ 㡰 CV ᆠ㡰    꾀 ᆠᆠ�ᨨ � �矄ᨨ  S 矄�ᨨ   矄ᆠᆠ� ᆠC҈� �␔  犨ᨨ �ᆠ�ᆠ矄ᨨ  �  ��鼀����矄 e҈ 㦨 e 㦨㡰� ᨨ 盐ᆠ 犨  犨ᨨ矄矄矄 ᨨ犨 �

C   ��盐 ᆠᆠ� ᆠᆠᨨ鼀矄C �ᨨ C �矄 ҈ ᲼꾀 ҈�桌

 矄�矄 � 犨�  �ᆠ�ᆠ泐矄ᨨ�矄 d   �ᆠ�ᆠ 矄 ᆠ  犨�   �ᆠ├ 矄矄 d = N æ mö ᆠᨨ 矄 ᨨ  鼀 泐�矄 K m = K ç҈ + ÷  ᨨ泐 è Nø K Î A ö æ � >҈㡰 ᆠᆠ� ᆠᔴ�矄 a ç ÷  盐 è d   ø ᨨ a犨�힘힘힘 ᲼ Î �矄 鼀���泐ᨨ  矄ᆠ桌 ᲼꾀 ҈黨桌 ҈ 꾀�m ᆠᆠ�ᨨ�矄ᆠ �  盐泐泐矄盐泐ᔼ�矄    �矄ᆠᨨ

ᆠ  ᨨ鼀 矄盐泐 �矄ᆠᨨ

ᆠ �

矄�矄ᨨ ᨨ 盐 ᆠ � �m ᆠᆠ�ᨨᔼ   �泐 X ᆠ  � 盐� � ᆠ � �矄�盐�ᨨ �矄   盐 ҈ ᨨ Xᨨ  矄� ��矄힘힘힘힘힘힘힘힘 [Main Sep.02, 2020 (I)]  꾀pFᆠᆠ�ᨨ�矄 盐泐ᆠ � 泐矄盐泐ᔼ �矄   �矄ᆠᨨ

ᆠ  ᨨ鼀 矄盐泐 �矄ᆠᨨ

ᆠ ᨨ ᨨ 盐 ᆠ � pFᆠᆠ�ᨨ�   ᆠᨨ矄�ᆠ �泐 �矄ᨨ矄�  �矄ᨨᆠ矄矄泐  �鼀 ᆠ ��矄 �矄�盐 犨  鼀�矄 �  㡰 ᲼㝐� 䰘 ᔼᔼ桌  �  �ᆠᆠᆠ�ᨨ矄C҈C C ᆠᆠ� ᆠ ᨨ ҈m ᆠ   泐盐 ᆠ � � ��泐 泐 ᆠᨨ

ᆠ � ᆠ�ᆠ盐�矄矄 ᨨ犨 �   ��盐 C҈�矄 

�  ᆠᨨ鼀泐犨�   �ᆠ�ᆠ 鼀� ᨨ  � 鼀���泐er ᆠᆠᨨ鼀ᨨ� ᨨᆠ 鼀 㡰V㦨V �矄 矄犨�ᆠ  S҈�矄ᆠᨨ矄 犨 � 矄犨�ᆠ  S�矄├ ᨨ ␔   ᆠᆠ�ᨨC�矄 盐泐ᆠ � S҈�矄ᨨ   S�矄ᆠᨨ矄 矄�鼀盐 ᨨ盐矄泐␔   ᆠᆠ�ᨨ矄 ᆠ ⼄盐���盐鼀 ᆠ �ᨨ C�矄 ᨨ盐 ᨨ�mC

盐ᨨ er㦨힘힘힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌

V

㡰 ⏌� 㡰 �⏌ ᆠ㡰 䰘⏌� 㡰 䰘⏌ 和 ᆠᆠ�ᨨ矄ᆠ ᨨ ᆠᆠ� ᆠ mF ᨨᆠᨨ

ᆠ �   ᆠᨨ ��盐�ᨨ  ᨨ ᨨ�     ᆠ� ᆠᆠ� ᆠ ᨨ

S

C҈ S҈

æ ҈ ö çè ÷ø mF ␔ �ᆠ ᨨ  ᆠᨨ鼀� �ᨨ  矄㡰矄 ᨨ犨 �  ��盐犨� ҈҈ ᆠ �  矄� 矄盐䁸 ᲼҈黨黨㜠㝐├矄桌 4 㡰

㡰

ᆠ㡰



2 

Integer Value Answer

꾀ᆠᆠ�ᨨᨨ ᆠᆠ� ᆠC 矄矄ᆠ� �d 犨 犨ᨨ矄 � �A ��ᨨ  犨

C

C

Fill in the Blanks

 犨ᨨᆠᆠ�ᨨ矄ᨨ ᆠᆠ� ᆠ矄C C ᆠᨨ

ᆠ �  ᆠ � ᨨᨨ � �  ᆠ V 泐�矄   �矄ᆠᨨ

ᆠ   ��ᨨ 犨

 矄ᨨ  ᆠᆠ�ᨨC�矄ᆠᨨ鼀泐 � 犨� 鼀� ᨨ  �ᆠ�ᆠᆠᨨ 矄 K ᨨ � �  ᆠ矄ᆠᨨ矄矄  ᆠᆠ�ᨨ矄 ᨨ犨ᆠᨨ鼀矄 ᲼҈黨㜠㝐├矄桌 � ��  �ᆠᆠᆠ�ᨨ矄ᆠ ᨨ A � 矄盐ᆠ    ᆠ 矄  �矄 ᆠd    矄ᆠᨨ

ᆠ ᨨ矄ᨨ盐ᆠᨨ 鼀 V矄矄 ᨨ犨 �   ��盐 ᲼҈黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-174

Physics

 ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐 犨ᨨ ᆠᆠ�ᨨ矄ᆠ ᨨ ᆠᆠ� ᆠC. 矄犨�ᆠ S҈ �矄 矄矄  �矄 ᨨ 盐泐ᆠ �   ᆠᆠ�ᨨ C҈    

矄   矄犨�ᆠ  S �矄    矄矄  ᨨ ᆠ �   ᆠᆠ�ᨨC. 꾀 矄ᨨ鼀�鼀S �矄矄    S �矄 矄矄 꾀 矄ᨨ鼀�鼀 ᲼꾀 ҈桌

– + ҈ �

6 

MCQs with One or More than One Correct Answer 

ᔼ    ᆠ�ᆠ盐� 矄 ᨨ犨  � ��泐  �矄 ᨨ ᆠ � ᨨ

ᆠᆠ�ᨨ矄 ├泐矄和҈ 和ᨨ  盐矄ᨨ   ᆠᆠ�ᨨ矄ᔴ҈㦨҈mFᔴ㦨mF C㦨C㦨mF ᲼꾀 ҈黨桌

黨

䰘

␔ �ᆠ ᨨ  矄鼀  矄㡰�矄⏌ᆠᨨᆠ䁸 㡰 ᔼ  ├泐 和 ҈ �矄 ├ ᆠᨨ矄  ᨨ ᨨ � �鼀 矄盐ᆠ    ᆠᆠ�ᨨ矄 盐泐ᆠ �  ᨨ� �  ᆠ 犨 ᨨ� 矄 턼犨�҈ 㡰 ├泐和҈�矄├ᆠᨨ矄  ᨨᨨ ��鼀矄盐ᆠ  ᆠᆠ�ᨨ矄  盐泐ᆠ � ᨨ犨├泐和�矄ᆠᨨ矄  �矄�鼀  � 矄  ᨨ盐矄ᆠ盐 ᆠᨨ矄矄矄�矄ᨨ 犨 ᨨ� 矄  턼㡰犨�꾀 ᨨ盐 ᨨ ᨨ҈矄 ᆠ�鼀ᆠ㡰 ᆠ㡰 꾀�鼀t㦨 ├泐和҈�矄ᆠᨨ矄  � 矄  ᨨ盐矄 ᆠ盐 �  ᆠᨨ矄 ᆠ�ᆠ盐�犨��鼀꾀 㡰 ᔼ  ├泐 和 ҈ �矄 ├ ᆠᨨ矄  ᨨ ᨨ � �鼀 矄盐ᆠ    ᆠᆠ�ᨨ矄 盐泐ᆠ �  ᨨ�ᆠᨨ矄矄  ᆠᆠ�ᨨ矄ᔴ҈犨� 꾀ᆠᆠ�ᨨ 矄 �ᆠ�ᆠ矄ᨨ  �ᆠ�ᆠ ᆠᨨ 矄 K 犨 �矄矄 ᆠᨨ矄҈⏌ᨨ   ᨨ �矄矄矄矄 ᨨ犨 �   ��盐 ᨨᆠᆠ� ᆠ ᨨ  ᆠᆠ�ᨨ�矄C犨 � ᨨ  ᨨ�ᨨ 犨�  �ᆠ�ᆠ � 犨 �矄C҈␔   ᆠᆠ�ᨨ�矄ᆠ �   ᆠᨨ 泐  �ᆠ�ᆠ�矄ᆠ �Q҈  矄 ᨨ  �矄ᆠ �Q ᆠ�ᆠ � �   �ᆠ�ᆠ �矄E҈  �  ᨨ ᨨ�ᨨ �矄Eᔴ ᨨᨨ矄 ᆠᨨᆠ ᨨ�ᨨ ⏌ᨨ�ᨨ 矄�� ᨨ� � � ᆠ矄 ᲼꾀 ҈桌 E҈ 㡰 E = ҈ Q҈  E

Q҈  ᆠ㡰 Q = K 

C + K 㡰 C = K ҈

�

�҈

҈

E҈ ҈ 㡰 E = K 

�

Q

E

和

和҈

ᆠ �ᨨ ҈�矄 ᨨ �矄

ᔴ҈

和

ᔴ

ᔴ

㡰 ᆠ �ᨨ  盐ᨨ C҈ �矄CV 㡰 ᆠ �ᨨ  盐ᨨ C҈ �矄CV ᆠ㡰 ᆠ �ᨨ  盐ᨨ C �矄 㡰 ᆠ �ᨨ  盐ᨨ C �矄CV 꾀 �ᆠ�ᆠ矄ᨨ  �ᆠ├ 矄矄d�矄� 矄 �  ᆠᆠ�ᨨ犨 ᨨ矄 ���矄x㦨 ᨨ矄�� �矄x㦨d 矄�矄⼄盐� �矄  ᨨ鼀 矄  ᆠᆠ�ᨨ�矄�� 矄ᨨ鼀ᆠ �꾀矄ᨨ �ᨨ矄 ᨨ鼀ᨨd ᲼҈黨黨和㜠㝐├矄桌 㡰  鼀� �盐 ᨨ  ᆠ�ᆠ � 鼀� 矄 矄鼀 㡰   �ᆠ�ᨨ ᨨ  ᆠ�ᆠ � 鼀� 矄 矄鼀 ᆠ㡰  ᆠ�ᆠᨨ �� ᆠ矄矄ᆠᨨ � 盐ᨨ盐矄泐 㡰  ᆠ�ᆠᨨ �� ᆠ矄矄 �矄   ᆠ矄矄  �� � ᆠ矄矄 꾀ᆠᆠ�ᨨᨨ A 矄�ᨨ

�矄ᆠ � ᨨᨨ � �  ᆠV    泐 �矄 �矄ᆠᨨ

ᆠ 꾀矄ᨨ  �ᆠ�ᆠᆠᨨ 矄 K �矄 

� 矄 犨  矄ᨨ  ᆠᆠ�ᨨ矄ᨨ矄ᨨ �   矄ᆠ 犨    矄 ᔼ  Q E   W  ᨨ 矄ᆠ�泐 鼀� �盐 ᨨ ᆠ �ᨨ ᆠ   ᆠ�ᆠ � 犨  矄   矄�矄� 矄 㡰  犨ᨨ├ ᨨ ᨨ  矄泐矄鼀� ⼄盐矄�ᨨ �  ᨨᆠ矄矄 ᨨ � 矄� � 矄 

᲼҈黨黨҈㜠㝐├矄桌 e  AV e  KAV 㡰 Q㦨 㡰 Q㦨 d d V e  AV  é ҈ù ᆠ㡰 E㦨 㡰 W㦨 ҈- ú ê Kd d ë K û 꾀 ᆠᆠ�ᨨ �矄 ᆠ �     ᆠ �� � 泐�矄   �矄ᆠᨨ

ᆠ ᔼ  矄ᨨ  ᆠᆠ�ᨨ 鼀ᨨ   泐鼀 矄ᨨ � 矄盐� �  矄 ᲼҈黨䰘㜠㝐├矄桌 㡰  ᆠ �ᨨ  ᆠᆠ�ᨨ� ᆠ矄矄 㡰  ᨨ�ᆠᨨ矄矄 矄� ᆠ矄矄 ᆠ㡰  ᆠᆠ� ᆠ� ᆠ矄矄 㡰   ᆠᨨ矄�ᆠ  �泐 矄ᨨ  �    ᆠᆠ�ᨨ � ᆠ矄矄 꾀�ᆠᆠ�ᨨ �矄ᆠᨨ

ᆠ ᨨ泐

⼄盐 ��矄ᆠ �ᨨ�ᆠ�ᆠ �   �泐 矄矄ᨨᆠ� 犨�  �矄ᆠᆠ�ᨨ�� 泐QVE U矄ᆠ�泐꾀 �ᆠ�ᆠ矄�矄 ᨨ犨� ᨨ 盐ᆠ ᨨ �   矄ᆠ 犨    矄 犨�  泐 矄� �

ᆠᨨ

ᆠ�ᨨ  ᆠᨨ矄ᨨ � �⼄盐 ��矄 ᨨ犨�� 泐 QVE U ᨨ �ᨨ盐矄ᨨ 矄 ᲼҈黨�㜠㝐├矄桌 㡰 Q > Q 㡰 V > V ᆠ㡰 E > E 㡰 U > U 

WWW.JEEBOOKS.IN

P-175

Electrostatic Potential and Capacitance

10 Subjective Problems �

犨ᨨᆠᆠ�ᨨ矄A B犨� ᆠᆠ��矄mF mF ᆠ �  ᨨ  ᨨ � �  ᆠᨨ  ҈    ҈  矄ᆠ�泐 矄ᨨ  ᆠᆠ�ᨨ矄ᆠᨨ

ᆠ 矄矄 ᨨ犨 �   ��盐犨� ᨨ 犨� ᨨ鼀ᆠ ᆠᆠ�ᨨ   盐  ᨨ  A �矄 ᨨ矄��    ᨨ  B �矄

��꾀 盐 ᆠ � mFᆠᆠ�ᨨC犨�  犨�矄 矄ᨨ    矄ᨨᆠᨨ鼀 ᆠ�ᆠ盐�ᔴᆠ盐 ᲼҈黨黨䰘㜠�㝐├矄桌

� 犨ᨨ   ᆠᆠ�ᨨ矄 A   B    矄鼀 矄�ᨨ d㦨�맔҈鼀犨  矄  ᨨ A B鼀 鼀矄ᆠ�泐꾀矄 ᨨ  �ᆠ�ᆠ ᆠᨨ 矄  � 鼀���泐㡰 K 㦨 黨  矄 �鼀 矄�ᨨ 矄矄盐ᆠ  �ᆠ  ᆠ泐 � 矄ᆠ犨

 矄ᨨ ᆠᆠ�ᨨB ᲼҈黨黨㜠졔졔㝐├矄桌 꾀

҈҈ 㡰

�

��

�㡰   � ᆠ �ᨨ   ᆠᆠ�ᨨ矄 ��㡰  鼀ᨨ盐 ᨨ ᆠᨨ矄�ᆠ �泐矄ᨨ �  矄泐矄鼀  ᨨ   ᆠᨨ鼀�ᨨ ᨨ  ᆠ�ᆠ盐�

ᆠᆠ� ᆠᨨ  ᆠᆠ�ᨨ 犨�    A  矄�ᨨ d�矄C 矄ᆠ犨

 矄�矄 � 犨� 犨ᨨ犨 �矄 ᨨ  �ᆠ�ᆠᆠᨨ 矄 矄 K҈   K 矄ᆠ�泐 �    ᆠᆠ� ᆠ ᨨ    ᲼҈黨黨㜠㝐├矄桌 矄盐� �ᆠᆠ�ᨨ

犨ᨨ矄⼄盐鼀矄ᨨ 矄� ҈鼀├҈鼀 �├ᆠᆠ�ᨨ� �� 矄盐ᆠ 犨泐 ᨨ  ᨨ  � �矄�矄 �ᆠ盐ᨨ ᨨ�矄盐 ᆠ�  ├ � 犨�  � 矄盐� �ᨨ� 矄ᆠᨨ

ᆠ ᨨ 泐ᨨ 鼀 � 矄  ᨨ犨 �ᆠ泐 � ᨨ ᨨ�矄 ᨨ ҈鼀矄҈ᔴᆠ盐 ᆠ盐  犨  ᨨ鼀   泐 盐� �  ᨨᆠ矄矄 �ᆠ�ᆠ ᆠᨨ 矄 ᨨ ᨨ�㦨҈҈e㦨�맔҈҈ᔴ҈鼀҈㡰 ᲼҈黨黨㜠㝐├矄桌



㡰





ᆠ㡰

�㡰  �ᆠ�ᆠ矄�矄ᆠ � 矄� 꾀矄矄 ᨨ犨 �  ��盐 㡰꾀�矄  ᆠ � ᨨᨨ � �  ᆠᨨ ҈҈ ᔴᆠ盐 ᆠᆠ� ᆠᨨ A   �泐矄ᨨ � � ��㡰 泐�矄 �矄ᆠᨨ

ᆠ      �ᆠ�ᆠ 矄 �矄 鼀ᨨ  ᨨ鼀 A  �   犨ᨨ├  ᨨ  泐     � ᆠ泐� 鼀ᨨ� � 矄 ᨨ鼀A ���㡰 矄鼀 �ᆠ�ᆠ矄�矄 ᨨ犨ᆠ � 矄� B �� � �ᆠᨨ鼀泐 犨ᨨᆠᆠ�ᨨ矄A B 

ᆠᨨ

ᆠ 矄矄 ᨨ犨 �  ��盐 ᆠ㡰ᔴᆠ盐  �泐 矄ᨨ �  矄泐矄鼀 �䰘  ��盐 矄 ᨨ犨矄犨ᨨ �  �ᆠ 和   ᆠᆠ�ᨨ矄 ᆠᨨ

ᆠ  ᨨ  泐犨�    矄犨�ᆠ Sᆠᨨ矄   꾀 ᔴ  ᔴ 

矄犨�ᆠ  �矄 ᨨ犨ᨨ      矄ᆠ犨  矄 ᨨ  ᆠᆠ�ᨨ矄�矄 � 犨�  �ᆠ�ᆠᨨ  �ᆠ�ᆠᆠᨨ 矄  ᨨ�鼀���泐㡰 �  �ᨨᨨ  ᨨᆠᨨ矄�ᆠ �泐矄ᨨ �

ᨨ  ᆠᆠ�ᨨ矄 ᨨ     � ᨨ 盐ᆠ�ᨨ  ᨨ   �ᆠ�ᆠ ᲼҈黨㜠㝐├矄桌

Topic-4 : Miscellaneous (Mixed Concepts) Problems 1 ҈

犨ᨨ � �ᆠ    鼀 矄 � �  矄�ᨨ ᨨ ҈ᆠ鼀ᆠᨨ

ᆠ ᨨᔴᨨ�矄ᨨ盐ᆠ ᨨ ᨨ � �  ᆠX꾀ᨨᨨ �矄矄 矄鼀� 犨泐 犨  犨ᨨ矄ᔼ�矄 ᨨ盐 ᨨ鼀ᨨ� ᨨ  �ᆠ和  矄  X�矄 泐 ᲼҈桌 㡰 ҈´ ҈�V 㡰 ҈´ ҈䰘V ᆠ㡰 ҈´ ҈黨V 㡰 ҈´ ҈҈V 6



㡰 ᆠ�ᆠ �  A�  ᆠ�泐㦨ᆠ�ᆠ �  B �  ᆠ�泐 㡰 ᆠ �  矄�泐A㦨ᆠ �  矄�泐B ᆠ㡰 ᨨ �A㦨ᨨ �B 㡰 ᨨᆠ�ᆠ �  盐  ᨨ盐�  矄盐 ᆠᨨ  ᆠ�泐 �矄q⏌e

MCQs with One Correct Answer

MCQs with One or More than One Correct Answer

꾀  �矄ᨨ�  ᆠ�泐 �矄 ᆠ  犨� �    ᆠ ᆠᨨ 盐ᆠᨨ 꾀 ᨨ矄�� ᆠ � q �矄 ᆠ     ᆠ ᨨ   ᆠ�泐  ᨨ� 矄A Bᨨ   ᆠ�泐矄盐 ᆠ矄矄 ᨨ犨 �

  ��盐 

᲼҈黨黨黨和㜠㝐├矄桌

A

q

B

7 

Match the Following

和� ᨨ� ᆠ �矄 ᆠ ᨨ  矄鼀鼀� �盐 q,    � �  �  鼀

矄矄矄 ᨨ犨 � ᔴᨨ盐鼀 㜠ᔼᔼᔼ

ᆠ ᆠ矄ᨨ� 㝐 � 턼矄矄� � ᨨ盐� 㝐 矄 ᨨ犨  E ᆠ�ᆠ �   V ᆠ�ᆠ ᨨ �㝐 ᨨ �� � �泐�矄 ᨨ㡰 盐ᨨ ��

ᆠ � �矄�盐�ᨨ 犨  ��矄矄ᨨ犨 犨 ᨨ矄泐矄鼀 �矄矄� ᨨᨨ�ᨨ 犨� ᆠᨨ 矄  �盐ᨨᆠ�泐ᨨ盐  � 턼 鼀� �ᆠ � 㝐 m  鼀� �ᆠ鼀ᨨ鼀 ᨨ  矄泐矄鼀�  �矄ᆠᨨ ��ᨨ 꾀矄矄盐鼀 ᆠ ᨨ� �ᆠ �ᨨ ⼄盐� ᨨ矄 泐ᆠ盐  ᲼黨桌

WWW.JEEBOOKS.IN

EBD_8341 P-176

Physics

ᔴᨨ盐鼀 㜠ᔼ

ᔴᨨ盐鼀 㜠ᔼᔼ 졔

꾀㡰

㡰

E㦨

 턼



ᔴ �矄 ᆠᨨ 矄ᨨ �盐  �ᨨ 㝐�矄 ᆠ ᨨ    �ᨨ 턼�矄 �ᆠ盐ᨨ  ᨨ    �ᨨ 



㝐 

졔



㡰

V¹

 졔 

⼄㡰 졔

ᔴ㡰

㡰

B㦨

ᔴ �矄ᨨ �  �ᆠ盐ᨨ턼⼄盐� 矄㝐�矄  鼀� 㜠ᨨ� 犨  犨ᨨ�

鼀ᨨ矄ᆠ �矄



ᔴ �矄  ᆠ  ᨨ  犨ᨨ ᆠᨨ  � 矄盐� � � �矄  ⼄盐 � 矄㝐�矄 ᆠᨨ鼀鼀ᨨ ᆠ ᨨ  � �矄턼�矄 �ᆠ盐 ᨨ  ᨨ  � �矄

 㝐 





m ¹ 0







㡰

졔  졔 㝐 턼

矄㡰



 㝐

 

ᔴ �矄ᆠ  ᆠᨨ 矄ᨨ ᆠ �ᨨ 矄� 矄a  a   鼀� ᨨ� 矄ᨨ  ᨨ �矄� 矄㝐�矄 ᆠ ᨨ   ᆠ �턼�矄ᨨ ᨨ �矄� 矄

턼 

졔  졔

)







㝐





Comprehension/Passage Based Questions 矄矄�㜠҈ ᔴᨨ 矄� 矄�鼀 ᔴᆠ�ᆠ盐�矄矄 ᨨ犨 �  ��盐҈ ᨨᆠ矄矄҈ᔼ  ᆠ�ᆠ盐� 矄犨�ᆠ 和�矄ᆠᨨ矄 㦨   ᆠᆠ�ᨨ�矄 盐泐ᆠ � ᨨᨨ� �ᆠ �� �ᆠᨨ � 盐矄 ᨨ�鼀 >> ᔴ㡰ᔼ  ᨨᆠ矄矄矄ᨨ鼀 �矄矄��ᨨ  쟼㡰ᨨᆠᆠ盐矄 ᆠᨨ矄矄 矄�矄 ᆠ  鼀ᨨ盐 ᨨ  �泐 � 泐矄ᨨ �

  盐泐ᆠ � ᆠᆠ�ᨨ�矄쟼ᔴ  ᨨᆠ矄矄ᔼ  �  ᨨᆠ矄矄 ᨨ��矄 �矄矄ᨨ   鼀� �   ᨨᆠ �� ��鼀 >> ᔴ   ᨨ��矄 8

 犨� ᨨ盐 �矄ᆠ �� �   ᆠᆠ�ᨨ   ��

 鼀� �   ᨨ�鼀 >> ᔴ ᨨᆠ矄矄�矄 ᨨ 鼀ᨨ �鼀泐�矄� � ᨨ�ᨨ  ᆠᆠ�ᨨ�矄ᆠ � ᨨ  矄鼀 � ᨨ�矄� ᨨᆠ矄矄҈

矄犨ᨨᨨᆠ矄矄矄 �ᆠ �  ��盐

�矄  ᨨ

和 

졔 



��盐҈ 



ᔴ �矄ᆠ ᨨ 犨ᨨᆠᨨ �  �ᆠ� 矄盐� �� �矄⼄盐 � 矄㝐�矄 鼀� 㜠ᨨ� 犨  ᆠ 矄ᨨ  � �矄턼�矄  �ᆠ盐ᨨ � ᨨ� � � ᆠ 矄 ᆠᨨ ᨨ � �矄 㡰 쟼ᔴ㦨쟼 㡰 쟼ᔴ㦨쟼ᔼ  ҈ ᆠ㡰 쟼ᔴ㦨 쟼  㡰 쟼ᔴ㦨쟼  � ᔼ ᨨᆠ矄矄ᨨ �泐 �矄矄� ᆠᨨ矄矄 矄�矄 ᆠ 쟼�矄 ᲼꾀 ҈䰘桌 æ҈ ҈ ö  㡰 쟼㦨 ᔴ 㡰 쟼㦨  ç ᔴ ÷   è ø ҈æ ҈ ö  ᆠ㡰 쟼㦨 ç ᔴ ÷ 㡰 쟼㦨 ᔴ è  ø 矄矄�㜠 ᔴᨨ 矄�  ᆠ盐 ᆠ泐� �ᆠᆠ 鼀ᨨ  ��   � � ��� ᆠᨨ 盐ᆠ� �矄  矄  � 矄盐� �ᆠ盐 矄盐 ᆠ矄矄 ᨨ犨  �   ��盐꾀 盐鼀 ᨨ 矄 �ᆠ矄 鼀 ᨨ  ��  犨��    矄ᨨ  鼀�   ᆠᨨ 犨�   ᆠᨨ 盐ᆠ� �鼀�ᆠ ᨨ  ᨨᨨ鼀 矄  �盐矄 ᨨ犨 �� ᨨ�矄ᨨ盐ᆠ 㡰�矄ᆠᨨ

ᆠ ᆠᨨ矄矄 ᆠᨨ 盐ᆠ� �矄矄盐ᆠ   ᨨᨨ鼀�矄 졔  ᨨ盐ᨨ �ᆠᨨ 盐ᆠ� �矄盐 ᆠ  矄犨��ᆠ � 犨�ᆠᨨ鼀⼄盐�ᨨ �犨�     泐� 矄犨� 盐泐ᆠᨨ�  犨�  ᨨ犨  ᆠᨨ �ᆠ� ᨨ 矄�盐�ᨨ ᆠ  ├ ᨨ ᨨ 盐ᨨ 矄ᨨ  盐ᨨ  鼀�ᨨ   矄 ᆠ�ᆠ � �  ᆠ 鼀ᆠ ᆠᨨ 矄�  ᨨ   ᨨ   ᆠᆠ�ᨨ꾀矄矄盐鼀     ᨨ ᆠᨨ�矄�ᨨ 矄犨  矄  � ᆠ�ᨨ 犨  鼀 �矄 ���� ᔼ� ᨨ��泐㡰 꾀

ᨨᆠ矄矄҈

  ⏌

 ᨨᆠ矄矄 

>> ᔴ

 ⏌











��盐 ᔼ ᨨᆠ矄矄҈  �泐矄ᨨ �  ᆠᆠ�ᨨ쟼ᔴ  �矄矄� ᆠᨨ矄矄矄�矄 ᆠ쟼 泐 ᲼꾀 ҈䰘桌



␔ �ᆠ ᨨ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄ᆠᨨᆠ䁸 ᲼꾀 ҈桌 㡰 矄犨�矄�ᆠ├ᨨ ᨨ 鼀�   㡰  矄 犨� ᨨ盐 ᆠ ᆠ├ ᨨ   ᨨᨨ鼀  ᆠ泐� � 矄鼀ᆠ � 泐犨 盐犨�

WWW.JEEBOOKS.IN

P-177

Electrostatic Potential and Capacitance

ᆠ㡰  矄 犨� ᨨ盐 ᆠ ᆠ├ ᨨ   ᨨᨨ鼀  ᆠ泐� � ᨨᨨ矄�ᆠ � 泐犨 盐犨� 㡰  矄 犨�  ᆠ盐 矄�鼀 鼀ᨨ �ᆠ 鼀ᨨ�ᨨ

犨  犨ᨨ矄

�ᆠ盐 �  矄 泐矄��矄 泐  鼀鼀�  ᆠ�ᆠ盐�犨� ᲼꾀 ҈桌 㡰 ᨨ 㡰 ᨨᨨ�ᨨ ᨨ ᨨ �

䰘

ᆠ㡰 ᨨᨨ�ᨨ ᨨ ҈⏌ 㡰 ᨨᨨ�ᨨ ᨨ  10 Subjective Problems ᨨ盐ᨨ� ᆠ �矄졔mC҈mC҈mC 졔mC



䰘   䰘 鼀- 鼀 + 鼀  + 鼀     矄ᆠ�泐ᨨ  泐㜠 �矄꾀�ᆠᨨ 鼀矄矄맔҈├�  ᆠ �졔҈mᔴ鼀ᨨ矄ᨨ � 㜠x �ᆠ�ᨨ ᔼ矄矄 x㦨졔 ¥ �矄V �  矄盐ᨨ V ᨨ犨 �ᆠ   �ᆠ犨�ᆠᨨ矄矄 ᨨ���  � 矄ᨨ ├� �ᆠ �泐 ᨨ  �ᆠ ᨨ��� 꾀矄矄盐鼀 矄ᆠ�矄��泐 ҈ 黨   ෌�  pe = 黨 ´ ҈ 鼀 ⏌ ᔴ  ᲼㜠҈㝐├矄桌  꾀 ᨨ 㜠ᆠᨨ 盐ᆠ� � �矄ᆠᨨ  �盐矄 盐 � ᨨ鼀ᨨ矄�� 矄盐 ᆠᆠ �  矄�泐 s �矄ᆠ ᨨ  �ᨨ盐 犨� �矄  �矄�ᆠ꾀�ᆠᨨ 鼀矄矄m ᨨ矄��ᆠ �q�矄 ᨨ ᨨ �  �矄ᨨ   �矄ᆠ ᨨ鼀 �� H犨� ᨨ� ��ᨨᆠ�泐 �ᆠ 矄 q m =  Î g ⏌ s ҈黨黨黨㜠҈㝐├矄㡰 㡰 �  盐ᨨ H�  �ᆠ盐矄ᆠ 矄  �矄ᆠ 㡰 和├ᆠ  ᨨ � �泐ᨨ  �ᆠ矄 盐 ᆠ�ᨨ

ᨨ �矄 ��   � �矄⼄盐���盐鼀ᨨ矄��ᨨ  꾀 ᆠᨨ 盐ᆠ� � 矄  S҈ ᨨ  �盐矄  �矄 ᆠ  ᨨ 

� 矄盐� �  꾀 ᨨ ᆠᨨ 盐ᆠ� �矄 Sᨨ  �盐矄 R�矄鼀ᨨ盐  ᨨ  � 矄盐� �矄 S�矄� ��泐盐 ᆠ � 

�   ᨨ� 矄 -

黨

҈

S҈�矄�� ᆠ �Qᨨ盐� � ᨨᆠᨨ ᆠ犨� S 鼀ᨨ S҈�矄ᆠ � 矄盐ᆠ   ᆠ �ᨨ ��矄��

Q錐 ��矄�� ᨨ盐� � ᨨᆠᨨ ᆠ犨� S 鼀ᨨ 

�矄ᨨᆠ 盐�矄  �鼀矄 ᲼҈黨黨㜠㝐├矄桌 㡰 �    ᆠᨨ矄�ᆠ  �泐 ᨨ  S    矄盐ᆠ ᆠᨨ ᆠ矄犨� S҈ 㡰 ␔ �矄 �鼀�� �盐ᨨ  �矄 �泐矄 n ® ¥ 䁸 ҈҈ 㡰 꾀矄矄盐鼀     ᨨ  矄  ᨨ 盐 � ᨨ鼀 鼀矄矄  矄�泐ᔴᆠ盐 �矄 �泐��  ᨨ 盐ᆠᨨ  鼀矄矄   �盐矄ᨨ   ᨨ�맔҈҈ ├�鼀꾀ᆠ �ᨨ Qᆠᨨ盐ᨨ鼀�矄盐 � ᨨ鼀泐 �矄�盐 ᨨ矄 �ᆠᨨ盐鼀ᨨ  �盐矄R鼀矄졠� 

 矄矄�ᨨ  ᨨ  �泐ᨨ  矄泐矄鼀 㡰 ␔  犨� ᆠᨨ矄ᨨ � �  矄矄�ᨨ  ᨨ    �泐   ᨨᆠᨨ鼀泐 �矄矄矄鼀     �� 矄   ���ᨨ  盐 鼀ᨨ �矄 �矄 ᆠᨨ 矄�盐 �ᆠ矄䁸 ᆠ㡰 ᔼ  矄鼀ᆠ �ᨨ Qᆠᨨ盐ᨨ鼀矄�  㡰ᨨ�矄 �� ᨨ矄 �ᆠᆠᨨ 盐ᆠᨨᨨ  矄鼀 �盐矄R犨  犨� �泐ᨨ  矄泐矄鼀䁸 ᲼҈黨黨㜠҈㝐├矄桌 ҈ 꾀ᨨ� �ᆠᨨ 鼀矄矄M �矄ᆠ  ᨨᨨ  ᨨ  鼀矄矄矄矄���  ᨨ 㜠ᆠᨨ 盐ᆠ� � 턼졔⼄ ᨨ  ᨨ   �  L 꾀 ᨨ  q 쟼 ᨨ�  �ᆠᨨ   矄鼀 턼㜠⼄ 鼀矄矄 �矄 ᆠ   ᨨ   ᨨ  ᨨ  ᨨ   犨ᨨ�ᆠ矄ᆠ泐ᆠ �矄졔q ⼄矄ᆠ�泐 �矄  �鼀 �矄  � ��ᨨ ᨨ 盐 � ᨨ鼀ᆠ�ᆠ � E 矄盐ᆠ   ᨨ 鼀├矄矄鼀 � q  矄泐ᨨ ᨨ盐� �㡰犨�   �  �ᆠ�ᨨ  �� �   矄矄�ᨨ  ᨨ  鼀� �鼀盐鼀�鼀    ᨨ ᨨ ᨨᆠᨨ鼀ᨨ   �  ��矄矄  ᲼҈黨黨㜠鼀├桌 ҈ �ᆠ矄ᆠ ᨨ 鼀矄矄҈�鼀 ᆠ泐� �ᆠ � q  矄盐矄   ᨨ鼀  ᆠᨨ鼀鼀ᨨ  ᨨ�  泐 � 矄盐 鼀矄矄矄矄矄� �矄ᆠ ҈ᆠ鼀ᨨ �ᔼ  �ᆠ矄�

⼄盐���盐鼀 ᨨᆠ  ᆠᨨ 矄ᨨ  ⼄盐� � �ᨨ 矄�  � ᆠ鼀ᆠᆠ盐 ᆠ �qᨨ ᆠ �ᆠ ├g㦨҈鼀⏌矄㡰 ᲼҈黨㜠�㝐├矄桌

Answer Key Topic-1 : Electrostatic Potential and equipotential surfaces ҈ ҈҈ ҈  ҈ ҈҈

ᆠ㡰  㡰  㡰  㡰 � ᆠ㡰  㡰 䰘 ᆠ㡰  㡰 黨 㡰 ҈ 㡰 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈ 㡰 ҈� 㡰 ҈ ᆠ㡰 ҈䰘 ᆠ㡰 ҈ 㡰 ҈黨 㡰  㡰 㡰  㡰  㡰  㡰 � 㡰  㡰 䰘 㡰  ᆠ 㡰 黨 ᆠ㡰 ᆠ 㡰 ҈ ᆠ 㡰   㡰  㡰 Topic-2 : Electric potential energy and work done in carrying a charge 㡰  ᆠ㡰  㡰  㡰 � 㡰  ᆠ㡰 䰘 ᆠ㡰  ᆠ㡰 黨 㡰 ҈ 㡰 㡰 ҈ 㡰 ҈ 㡰 Topic-3 : Capacitors, grouping of capacitors and energy stored in a capacitor

҈ ҈҈ ҈ ҈

㡰 㡰 㡰 ᆠ㡰

 ҈  

㡰 㡰 ᆠ㡰 㡰

҈

҈㡰

 㡰



 㡰 黨  㡰

 ҈  

㡰 㡰 㡰 㡰

 㡰 � ᆠ㡰

㡰  㡰 ҈ 㡰  㡰    ҈�㡰 � 㡰 ⧤+ �҈ ᆠ 㡰 �  㡰  ҈  

㡰 ᆠ㡰 㡰 ᆠ㡰

� ҈� � �

ᆠ㡰 㡰 㡰 㡰

㡰  㡰 㡰 ҈ ᆠ㡰 㡰  㡰 㡰  㡰 쟼꾀 -쟼  꾀    �  㡰 䰘 ҈䰘 䰘 䰘

黨 ҈黨 黨 黨

㡰 㡰 㡰 㡰

҈   

㡰 㡰 㡰 㡰

䰘 ᆠ 㡰

Topic-4 : Miscellaneous (Mixex Concepts) Problems ҈

ᆠ㡰

 ᆠ 㡰

 꾀㜠 矄㡰㜠 矄㡰ᔴ㜠 ⼄㡰㜠 矄㡰

 㡰

� ᆠ㡰

 ᆠ㡰

䰘 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-178

Physics

17

Current Electricity

Topic-1 : Electric Current, Drift of Electrons, Ohm's Law, Resistance and Resistivity 1 ҈





MCQs with One Correct Answer

꾀ᆠ�ᆠ盐�ᨨ� 泐졠 鼀矄犨盐矄矄鼀鼀 ᨨ鼀 � 矄�矄ᨨᆠᨨ

ᆠ ᆠᨨᆠ泐ᨨ 矄�矄ᨨᔼ

 ᆠ�ᆠ盐� ᲼㝐� 和 ᔼᔼ㡰桌 㡰 鼀鼀�矄犨泐矄盐矄 �  ᨨ鼀�矄矄�矄 㡰 ᨨ 鼀鼀 ᨨ鼀鼀盐矄ᆠᨨ

ᆠ �  ᆠ㡰 鼀鼀�矄犨泐矄ᆠᨨ

ᆠ � 矄�矄 ᨨ鼀 �  㡰 ᨨ 鼀鼀 ᨨ鼀鼀盐矄ᆠᨨ

ᆠ � 矄�矄 ᔴᨨ 矄�  ᨨ盐 ᆠᨨ 盐ᆠ� � 鼀�矄 ᆠᨨ 盐 �矄  鼀ᆠ盐泐 盐鼀� �盐鼀犨� 矄�矄��泐rCrTrM rA 矄ᆠ�泐   ᲼㝐� 和 ᔼ㡰桌 㡰 rC > r A > rT 㡰 r M > r A > rC ᆠ㡰 r A > rT > rC 㡰 r A > rM > rC

ᨨ� 泐졠 鼀矄 犨  矄盐   ᆠᨨ

ᆠ矄  ᨨ鼀 ᆠᨨ矄矄 泐矄矄 ᨨ犨 �   ��盐 鼀矄盐 ᨨ� �矄ᨨ  矄  盐 ᆠ�ᨨ  ᨨ    ᆠ盐      ᨨᨨ犨� �� �矄ᨨ�   ᲼㝐� ҈꾀҈黨 ᔼ㡰桌



�

ᆠ㡰 ᨨ � �  ᆠᆠᨨ矄矄 泐�矄҈�犨 

�矄 矄ᆠ盐 ᨨ ҈鼀꾀 㡰 鼀 ᨨ  泐�矄҈�  盐ᨨ  �矄҈�W 꾀 ᆠ盐  ᨨ  �꾀 矄矄矄  ᨨ盐�   ᆠᨨ ᆠᨨ 盐ᆠᨨ 矄�矄��泐㡰㦨҈䰘맔҈W鼀㡰ᨨ  �盐矄ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ � 鼀鼀 �  鼀ᨨ��泐ᨨ  ᆠ �矄�  � � ᨨᆠ�泐 �矄҈҈맔҈鼀⏌矄 ᲼㝐� ҈꾀҈黨 ᔼ㡰桌 㡰 ҈鼀⏌矄 㡰 ҈�鼀⏌矄 ᆠ㡰 ҈鼀⏌矄 㡰 ҈鼀⏌矄 和ᆠ犨 犨ᨨᆠᨨ ᆠ �ᆠᆠᨨ 盐ᆠ� �矄 矄ᨨ  �� a b b>a㡰�矄 � 犨� 鼀 �盐鼀ᨨ 矄�矄��泐r  矄�矄 ᆠ犨  犨ᨨ矄 矄犨� ᲼㝐� ҈꾀҈黨 ᔼᔼ㡰桌 㡰

r æ҈ ҈ö ç - ÷ p è a b ø

r æ҈ ҈ö ç - ÷ p è a b ø

r æ҈ ҈ö r æ҈ ҈ö 㡰 ç + ÷ ç + ÷ p è a b ø p è a b ø ᔼ ᆠᨨ 盐ᆠᨨ�   盐鼀ᨨ ᆠᨨ 盐ᆠ�ᨨ ᆠᨨ 矄 盐 �ᨨ盐鼀�矄�맔҈ 鼀   鼀  �鼀�矄 �fs 鼀ᨨ矄ᆠᨨ 㡰�矄ᨨ �鼀矄�矄��泐�矄 鼀  㦨黨҈맔҈҈ ├�㡰 ᲼㝐� 黨꾀҈黨 ᔼᔼ㡰桌 㡰 ҈W鼀 㡰 ҈䰘W鼀 ᆠ㡰 ҈W鼀 㡰 ҈�W鼀 꾀W矄�矄ᨨ 矄ᆠ� ᆠᨨᨨᆠᨨ ᔼ ᨨ ᆠ矄   ᆠᨨᨨ泐� �  ᆠᨨ   犨矄�矄 ᆠ犨�  ᲼㝐� 꾀�҈黨 ᔼ㡰桌

ᆠ㡰



䰘

㡰 ҈W 

ᔼ ᨨ�矄鼀ᨨ矄 ᨨ�  � 泐 ᆠᨨᆠ矄鼀  㡰  鼀  ᨨ    泐 �矄 ҈�    �矄 �   矄�矄 ᆠ�矄҈�W 㡰 盐ᨨ  矄�矄 ᆠ �矄҈�W

㡰

㡰 W

ᆠ㡰 W



�W

ᆠ �ᨨ ᆠᆠ�ᨨ� ᆠ�ᆠ盐�矄 盐 ᆠ�ᨨ ᨨ �鼀�矄矄 ᨨ犨 �   ��盐 ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌  �  ⼄ Ҙᆠ㡰   





 矄㡰





WWW.JEEBOOKS.IN

P-179

Current Electricity

␔ �矄 盐ᨨ ᆠ盐 㦨矄䁸 㡰 ᨨ 㡰 Ҙ꾀 ᆠ㡰 Ҙ꾀 㡰 ҈�Ҙ꾀 � 矄 ᨨ ᆠᨨ 矄犨  ҈�꾀ᨨ ᆠ盐  ᨨ犨矄�  ᆠᨨ犨�ᨨ ᆠᨨ矄矄矄ᆠ�ᨨ �鼀鼀�矄vᔼ  ᆠᨨ

 矄�泐� ᆠᨨ�矄黨맔҈⏌鼀 盐ᨨ v� 鼀鼀⏌矄 ᆠᨨ矄ᨨ ├ᆠ �ᨨ ᆠᨨ ᨨ㦨҈맔҈҈黨ᔴ㡰 ᲼㝐� 黨 ҈黨 ᔼ㡰桌 㡰  㡰  ᆠ㡰  㡰  ҈ 꾀ᆠᨨ 矄�矄 ᆠ 矄 ᨨᨨ犨� �ᆠᨨᨨ盐ᆠᨨ ␔ �矄   盐 ᨨ    矄�矄 ᆠ䁸 ᲼㝐� 黨 ҈黨 ᔼᔼ㡰桌   黨

҈� 和盐ᨨ矄  � ᨨᆠ�泐n � 鼀�� 犨�   � ᆠ�ᆠ � 쟼矄 n µ 쟼   ᔼ�  ᨨ 犨�鼀 ᨨ 矄盐ᆠ 鼀��矄矄�� 泐 ᲼㝐� 졠 � 꾀�҈҈�桌 



㡰

㡰 ᔼ







෌졠Ӹ ෌ᨨ 

㡰 �├W᠀�奠 㡰 �├W᠀�奠 ᆠ㡰 㝐W᠀�奠 㡰 㝐W᠀҈奠 ҈҈ 꾀 � � 鼀  矄  矄�矄 ᆠ ᨨ  ҈W  ᨨᨨ鼀 鼀盐␔  ��矄ᆠᨨ

ᆠ ᨨ矄盐泐ᨨ  矄 泐ᆠ盐 ᨨ 꾀矄矄矄� � 鼀盐�矄� ᔴ 鼀ᨨ    ᨨᨨ鼀 鼀盐 ␔  �矄   鼀盐 ᆠᨨ �ᆠ� ᨨ 矄�矄 ᆠᨨ   � �鼀 䁸 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ҈맔҈ ᔴ҈ 㡰 �맔҈ ᔴ҈ ᆠ㡰 맔҈ ᔴ҈ 㡰 �맔҈ ᔴ҈ ҈ 꾀盐 � ᨨ鼀犨�ᨨ  � l  �盐矄 矄矄�矄 ᆠᨨ  ҈Wᔼ�矄ᆠ矄� ᨨ犨�ᨨ  �盐矄  矄�矄 ᆠᨨ 

犨犨�犨� ᲼㝐� 졠 � 꾀�黨҈䰘桌 㡰 ҈W 㡰 W ᆠ㡰 W 㡰 ҈W ҈ 꾀 � � �� ᆠ �ᨨ 盐 � ᨨ鼀ᆠ�ᆠᆠ �  矄�泐l �矄ᨨ �  �矄ᨨ  ᆠ�ᆠ泐ᆠᨨ 盐ᆠ� �� � � ᆠ泐� �ᆠ矄 ᨨ  �盐矄 꾀�鼀㦨 矄ᆠ� 矄�   ᆠ泐� �矄 � 犨� 鼀�ᨨ 鼀���泐e ᆠ�ᆠᆠᨨ 盐ᆠ��泐s ᆠ�ᆠᆠᨨ 盐ᆠ�ᨨ �   鼀� ᨨᨨ犨矄졠 鼀Ἐ矄犨␔ �ᆠ ᨨ ᨨ   ᨨᨨ犨� � � 矄 矄 矄ᆠ�矄   矄盐矄⼄盐  ��ᨨ  ᨨ    鼀� �盐  ᨨ  ᆠ盐   矄�泐 㡰   泐 ᨨ�  �    鼀�䁸 ᲼꾀 ҈桌

ᆠ㡰



ᔼ ᔼ ҈ ᔴᨨ 矄�  � 矄⼄盐矄 ᨨ 矄� L  �ᆠ├ 矄矄t 鼀 ᨨ 鼀�ᨨ 矄�矄��泐r 矄�矄 ᆠ犨

犨ᨨ ᨨᨨ矄� ᆠ矄 矄 ᨨ犨  泐 矄    矄�    ��盐�矄 ᲼҈桌 㡰 �ᆠ泐ᨨᨨ�ᨨ ᨨL

㡰 �ᆠ泐ᨨᨨ�ᨨ ᨨt ᆠ㡰 �   ᨨ L

 t

㡰 �   ᨨ t

L

҈䰘 ᨨ� 泐졠 鼀矄犨  矄盐   �矄ᨨ�   犨�   矄 矄�矄ᨨRT �� 矄�矄 ᆠR҈矄鼀矄�矄 ᆠR犨ᨨ �  �ᆠ� ᨨ鼀矄G҈ G �ᨨ� 矄ᨨ盐ᆠV ᆠᨨᆠᆠ�ᆠ盐�ᨨᆠ泐ᨨ盐  �鼀 �矄 ᲼҈桌 G҈ R

㡰

R



㡰

V

 㡰

 㡰

ᆠ㡰 㡰

㡰 



㡰

㡰

 㡰

 㡰



҈ 쟼 矄矄 犨 �ᆠ ᨨ    ᨨᨨ犨� � 矄 盐矄 ᆠ  盐矄 ᨨ ᲼和桌 � 泐졠 鼀矄犨䁸

㡰 ᆠ㡰

㡰 㡰



㡰



҈ ␔  �ᨨ � �  ᆠ�矄� ᆠᨨ矄矄犨�ᨨ  � ҈鼀  � 矄 ᨨ ᆠᨨ 矄�矄�맔҈鼀矄҈ ᔼ   ᆠᨨ   矄�泐 �   犨� �矄  맔 ҈ 鼀   矄�矄��泐ᨨ  鼀��矄ᆠᨨ矄ᨨ ᲼㝐� ҈�桌 㡰 ҈맔҈W鼀 㡰 ҈맔҈�W鼀 ᆠ㡰 ҈맔҈W鼀 㡰 ҈맔҈䰘W鼀

㡰

WWW.JEEBOOKS.IN

EBD_8341 P-180

Physics

outer radius is R2. If a voltage V0 is applied between its two ends, a current I flows in it. In addition, it is observed that a transverse voltage DV develops between its inner and outer surfaces due to purely kinetic effects of moving electrons (ignore any role of the magnetic field due to the current). Then (figure is schematic and not drawn to scale) [Adv. 2020]

(c)

DV

(d) 19.

20.

A piece of copper and another of germanium are cooled from room temperature to 80° K. The resistance of [1988 - 1 Mark] (a) each of them increases (b) each of them decreases (c) copper increases and germanium decreases (d) copper decreases and germanium increases The temperature coefficient of resistance of a wire is 0.00125 per °C. At 300 K, its resistance is 1 ohm. This resistance of the wire will be 2 ohm at. [1980] (a) 1154 K (b) 1100 K (c) 1400 K (d) 1127 K 5

21.

True / False

The current –voltage graphs for a given metallic wire at two different temperatures T1 and T2 are shown in the figure. [1985 - 3 Marks]

T1 I

T2

V The temperature T2 is greater than T1. 22.

Electrons in a conductor have no motion in the absence of a potential difference across it. [1982 - 2 Marks] 6

23.

MCQs with One or More than One Correct Answer

Shown in the figure is a semicircular metallic strip that has thickness t and resistivity r. Its inner radius is R1 and

R2 R1

I

I

V0

v0 t æ R2 ö ln ç ÷ pr è R1 ø (b) the outer surface is at a higher voltage than the inner surface (c) the outer surface is at a lower voltage than the inner surface (d) DV µ I 2

(a) I =

9

Assertion and Reason Type Questions

24. Read the following statements carefully: [1993-2 Marks] Y : The resistivity of a semiconductor decreases with increase of temperature. Z : In a conducing solid, the rate of collisions between free electrons and ions increases with increase of temperature Select the correct statement(s) from the following; (a) Y is true but Z is false (b) Y is false but Z is true (c) Both Y and Z are true (d) Y is true and Z is the correct reason for Y 10 Subjective Problems 25. If a copper wire is stretched to make it 0.1奠 longer what is the percentage change in its resistance? [1978]

Topic-2 : Combination of Resistances 1 1.

MCQs with One Correct Answer

In the given circuit diagram, a wire is joining points B and D. The current in this wire is: [Main 9 Jan. 2020, (I)] (a) 0.4A

(b) 2A

(c) 4A

(d) zero

WWW.JEEBOOKS.IN

P-181

Current Electricity



ᆠ盐 I҈ � A㡰 ᨨ犨� � ᨨ盐� ҈W矄�矄ᨨ�   ᨨᨨ犨� �ᆠ�ᆠ盐��矄 ᲼㝐� 䰘  ᔼ㡰桌

㡰

CE

r҈  ҈ + 㡰

ᆠ㡰 ᔴ쟼 㡰

CE

r҈  + 㡰





㡰  㡰 � ᆠ㡰  㡰 � 꾀鼀犨�ᨨ 矄�矄 ᆠW�矄ᨨ � ᨨ鼀├盐 � ᨨ鼀 犨�ᨨ  ᨨ盐�矄�ᨨ盐矄 �  �矄 犨犨��矄 ᨨ犨     矄ᨨ�  ᨨ鼀├ᆠ�ᆠᔼ 犨ᨨᨨ� 矄ᨨ

 ᆠ�ᆠ鼀├  �  ᆠ  ⼄盐�  矄�矄 ᆠ犨  矄犨ᨨᨨ� 矄犨� ᲼㝐� 黨꾀҈黨 ᔼᔼ㡰桌 ҈ � � 䰘 W W W W 㡰 ᆠ㡰 㡰 �    ᔼ   ��盐矄 ᨨ犨 犨 �矄 ᆠ盐  � 꾀鼀㡰 犨

ᨨ鼀 泐䁸Ӹᨨ盐��  ᲼㝐� 꾀҈黨 ᔼᔼ㡰桌 ҈㦨҈�W 㦨҈W 㦨W 㦨�W �㦨�W 㦨W쟼㦨҈�

㡰



ᔼ  ᨨᆠ�ᆠ盐� ᆠ盐 � ᆠ 矄�矄 ᆠ�矄 ᲼㝐� ҈䰘桌 㡰 �꾀 㡰 꾀 ᆠ㡰 ҈꾀 㡰 �꾀 黨

ᔼ  盐鼀� �盐鼀 꾀㡰ᨨ 矄⼄盐ᆠᨨ矄矄矄ᆠ�ᨨ 矄⼄盐 ᨨ�矄 �  �矄 � 犨� �ᨨ  㡰矄矄 ᨨ犨 �   ��盐

ᆠ�ᆠ矄�矄���矄ᨨ 꾀  䰘맔҈W鼀 ҈ 맔 ҈䰘 W 鼀 矄ᆠ�泐  ᆠ�ᆠ 矄�矄 ᆠ 犨  犨ᨨ ᆠ矄P Qᨨ  ᆠᨨ鼀ᨨ矄��矄 ᲼꾀 ҈�桌 㡰

䰘� ҘW 

㡰

҈䰘� ҘW  

ᆠ㡰

҈䰘� ҘW 黨



�鼀鼀

꾀 

䰘� 鼀鼀  ҘW 㡰 ҈ 䰘鼀鼀 ҈ 和� ⼄盐矄�矄 ᆠ矄ᆠᨨ

ᆠ 犨 ᨨ� 矄턼    矄 矄 ᨨ犨  �  ��盐    矄�矄 ᆠ 犨�  鼀 �鼀盐鼀犨   ᲼㝐� 졠 � 꾀��҈桌

�



㡰 ҈⏌ 㡰 䰘⏌҈ ᆠ㡰 黨⏌ 㡰 ⏌ 꾀盐 � ᨨ鼀鼀�ᆠ犨� 矄矄�矄 ᆠᨨ ҈W �矄   � ᨨ   ⼄盐� � �     矄�矄 ᆠ 犨   泐 犨ᨨ�ᆠ矄 ᨨ    � � �矄 ᲼㝐� ҈ ҈黨 ᔼ㡰桌 㡰 W 㡰 W ᆠ㡰 ҈␔ 㡰  ␔ ᔼ  �� ᆠ�ᆠ盐�矄�矄 ᆠ矄ᨨ 盐Rᨨ 鼀ᆠ 

⼄盐� 矄�矄 ᆠ犨 A B�矄 ᲼㝐� 졠 � 꾀�҈�҈桌



r

r r r 턼





�R �R ᆠ㡰 㡰 R   ᔼ  �� ᆠ�ᆠ盐� ��鼀犨   ᆠ盐 ᆠ 矄矄 泐 矄 �    ᆠ�ᆠ盐�   ᆠ � ᨨ    ᆠᆠ�ᨨ ᨨ ᆠᆠ� ᆠᔴ犨� ᲼㝐� ҈䰘桌 r 㡰 CE +   㡰

㡰 R 䰘

㡰

r



r

㡰   㡰  턼 ᆠ㡰 턼  㡰 꾀 泐犨ᨨᨨ� 矄 ҈҈ � ᨨ盐 盐ᨨ ᆠ盐  ᨨ盐� W矄�矄 ᆠ ᨨ  �� ᆠ�ᆠ盐� ᲼�和桌  ҈W

�W

҈

 W

㡰 ᨨ

㡰 A

ᆠ㡰�A

㡰 A

WWW.JEEBOOKS.IN

EBD_8341 P-182

҈

Physics

和� �  �ᆠ矄�矄ᨨ矄ᆠᨨ

ᆠ 矄矄 ᨨ犨 �   ��盐

⼄盐� 矄�矄 ᆠ犨� ᲼和桌 R

P

R

R

R R

V

R

㡰 㝐 �鼀盐鼀犨 P R 㡰 㝐 �鼀盐鼀犨 Q R ᆠ㡰 㝐 �鼀盐鼀犨  턼 㡰 꾀⼄盐

 ᆠ�矄�矄 ᆠ犨 ᨨ� 矄 P Qᨨ   ᆠ�ᆠᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐�矄 ᲼和桌 㡰

 Rr R+r

R

R R + r 㡰 㡰  P R + r ᆠ㡰 r졔R

҈

Fill in the Blanks

҈䰘 ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 ᨨ犨ᆠ 泐�矄�  矄

�  矄�矄 ᆠᨨ ᨨ 鼀

Q

R

҈

4

A

R

R

R

B

R R

r R

 � ��  � ᨨ鼀V�矄 ᲼҈黨黨䰘㜠㝐├矄桌 ҈ ⼄盐� 矄�矄 ᆠ犨 ᨨ� 矄A Bᨨ   ᆠ�ᆠ盐��� ᨨ犨�矄W  ᲼҈黨黨䰘㜠㝐├矄桌

R

r R

Q

6 MCQs with One or More than One Correct Answer ҈黨 ᨨ ᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐᲼黨桌 ├W



├W

R

I

�R + r 㡰 

ᆠ盐 ��  ᆠ�ᆠ盐� 矄 ��㡰�矄 ᲼҈黨㜠҈㝐├桌

V

R

҈�├W

� W 

㡰 㡰 ᆠ㡰 㡰

W 

 W 

㡰

҈ 꾀 �

㡰

҈ 꾀 ҈�

ᆠ㡰

҈ 꾀 ҈



҈ 꾀 �

 ᆠ盐 I ᨨ盐�  泐�矄䰘�鼀꾀  ᨨ � �  ᆠᆠᨨ矄矄RL�矄҈ �ᨨᨨ ᨨ犨矄 �矄矄� � R҈ R�矄 � R҈ R� ᆠ  � 鼀� �盐 ᨨ  ᨨ犨 �矄矄� � R犨� ᆠ矄泐 ᆠᨨᨨ 黨  ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐 ᆠ盐  ᨨ盐� ᲼҈黨黨和㜠㝐├矄桌 3W

2 Integer Value Answer ҈� ᔼ   ᨨᨨ犨� �ᆠ�ᆠ盐� ᆠ盐  ᨨ盐�  矄�矄ᨨ R 㦨W㡰�矄I鼀矄 盐ᨨ I�矄 ᲼꾀 ҈�桌

2W

9V

2W

8W

8W

4W

㦨W㡰 2W

㡰 㡰 ᆠ㡰 㡰

3

Numeric Answer

҈ 矄�矄ᆠᨨ鼀� �ᨨ ᨨ 犨ᨨ�矄ᨨ ᨨ  矄鼀 鼀 ҈盐 �  �  矄�矄 ᆠᨨ W �W �矄ᆠᨨ

ᆠ ᨨ ᆠᨨ鼀� �ᨨ ᨨ 犨ᨨ矄�矄ᨨ矄 W  W ᨨ� �  ᆠᆠᨨ矄矄 泐ᨨ �  矄�矄 ᆠW�矄 ᨨ 盐ᨨ R � W㡰�矄 힘힘힘힘힘힘힘힘힘 ᲼㝐�   ᔼᔼ㡰桌

2W

2W

 W 矄�矄ᨨ�矄�꾀  W 矄�矄ᨨ�矄�꾀  W 矄�矄ᨨ�矄�꾀  W 矄�矄ᨨ�矄�꾀

10 Subjective Problems ҈ 꾀 � � �  犨ᨨ├ᨨ 矄�矄 ᆠ矄�矄ᆠᨨ 矄盐ᆠ 犨� ҈ᨨ 鼀 ᨨ 鼀矄�矄 ᆠ矄矄矄 ᨨ犨 �  �� ᲼҈黨䰘㜠䰘㝐├矄桌 꾀 

҈W

W

҈W

҈W

W

W

҈W

W

 ��

WWW.JEEBOOKS.IN

P-183

Current Electricity

ᨨ泐犨 A B 矄 �����   矄�矄 ᆠ �㡰 和 ᨨ犨   ᆠ�矄�矄 ᆠ犨 A B �矄ᨨ 鼀矄 ��㡰 ␔ �矄 ᆠ盐  矄矄矄 ᨨ盐�  ᨨ 鼀 矄�矄 ᆠ 矄ᨨ 泐䁸

 꾀矄�矄 ᆠ矄�   ��鼀ᨨ犨� ᨨ 鼀矄 �    ᆠ�矄�矄 ᆠ犨  ᨨ� 矄A B᲼҈黨䰘黨桌  

 





 꾀



 

Topic-3 : Kirchhoff’s Laws, Cells, Thermo e.m.f. & Electrolysis MCQs with One Correct Answer

1 ҈

5W 10W

20 2W



҈

4W

ᔼ   ��盐矄 ᨨ犨  ᆠ盐 �  ҈泐�矄ᆠᨨ矄 ᨨ ᲼㝐� 和 ᔼᔼ㡰桌 㡰 䰘҈꾀 ᨨ鼀ᨨ矄��ᨨ ��鼀�  㡰 꾀 ᨨ鼀ᨨ矄��ᨨ ��鼀�  ᆠ㡰 ҈꾀 ᨨ鼀ᨨ矄��ᨨ ��鼀�  㡰 꾀 ᨨ鼀 ��ᨨᨨ矄��鼀�  ᔼ  ᆠ�ᆠ盐��� �   ��盐ᆠ盐 矄�  �   ᆠ 矄  盐ᨨ ᨨ 矄�矄ᨨ矄 ᨨ犨   ᨨ �ᨨ�  B犨� 矄ᆠᨨ ᨨ� A�矄᲼㝐� 和� ᔼᔼ㡰桌 

D

E ҈꾀

�

B

W A

C

҈



꾀 A

F



㡰 졔 㡰  ᆠ㡰 ҈ 㡰 졔҈

盐ᨨ ᆠ盐 �҈ ᨨ犨� � ᨨ鼀AᨨC�  ᆠ�ᆠ盐� ��鼀�矄 ᲼㝐� 和 ᔼᔼ㡰桌  �

䰘

B

W W �҈

�W W

W

㡰 ҈W 㡰 �W ᆠ㡰 ҈�W 㡰 W ᨨ ᆠ�ᆠ盐�矄 ᨨ犨 犨�  ҈㦨҈W 㦨W쟼҈㦨  쟼㦨쟼㦨 ᨨ � �  ᆠ犨   ᨨ� 矄�a �b�矄ᨨ �鼀泐 � 㡰 ᲼㝐� 꾀�҈黨 ᔼ㡰桌

㡰 䰘 㡰  ᆠ㡰 䰘 㡰  꾀ᆠ ᨨ �   矄�矄 ᆠr �矄ᆠ盐  ᨨ盐�  

  矄�矄 ᆠ  ᨨ犨 � 泐 ᆠᨨ    矄�矄 ᆠ犨�鼀 �鼀盐鼀犨   ᲼㝐� 꾀҈黨 ᔼᔼ㡰桌 㡰 㦨҈r 㡰 㦨҈r ᆠ㡰 㦨r 㡰 㦨r ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨  ᨨ � �  ᆠ犨 꾀  �矄 ᲼㝐� ҈҈ ҈黨 ᔼᔼ㡰桌



�W

W

W



҈W



҈W





D



҈

㝐 C

A

҈W

㡰 꾀 㡰 꾀 ᆠ㡰 ҈꾀 㡰 �꾀 ᔼ  �� ᆠ�ᆠ盐� � ᨨ鼀ᆠᨨ

ᆠ ᆠᨨ矄矄  ҈W 矄�矄 ᆠ 矄 �  矄�矄 ᆠᨨ ᆠ ᆠ�矄 ᲼㝐� ҈꾀҈黨 ᔼ㡰桌

҈W ᔴ







㡰 ҈ 㡰  ᆠ㡰  㡰  ᔼ  �� ᆠ�ᆠ盐� ᆠ矄  ᨨ�  矄�矄 ᆠ

 ᆠ盐 矄 �  꾀鼀矄㡰 矄矄� �  ᨨ盐�  矄�矄 ᆠ ҈  矄ᆠ�泐 ᲼㝐� ҈ ҈黨 ᔼ㡰桌

WWW.JEEBOOKS.IN

EBD_8341 P-184

Physics

㡰 ҈ 㡰  ᆠ㡰 � 㡰 ҈ 黨 犨ᨨ�矄犨� 鼀 ҈ ҈ᆠᨨ

ᆠ �

 ᆠᨨ矄矄  ᨨ  矄�矄ᨨ ᨨ  ҈W  �   矄�矄 ᆠ矄ᨨ  犨ᨨ�矄҈W W矄ᆠ�泐

ᨨ�ᆠᨨ矄矄 ᨨ �矄犨  ᲼㝐� ҈桌 㡰 ҈҈ ҈҈䰘 㡰 ҈҈� ҈҈ ᆠ㡰 ҈҈ ҈҈� 㡰 ҈҈䰘 ҈҈ ҈ ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨  ᆠ盐 �  ҈W矄�矄ᨨ�矄 ᲼㝐� ҈�桌



 W ҈W

犨�ᨨ  矄鼀鼀� ᆠᨨ矄矄㜠矄ᆠ�ᨨ 盐ᨨ  � L 鼀盐ᨨ  犨��矄�矄 泐 矄鼀鼀ᨨ盐  ᲼҈和桌 DT�  矄鼀�鼀t 盐ᨨ N �矄 㡰  㡰  ᆠ㡰  㡰 黨 ҈ 꾀泐ᨨ �  矄�矄 ᆠW�矄ᆠᨨ

ᆠ ᨨ 

犨ᨨ├ᨨ 矄�矄 ᆠ矄矄矄 ᨨ犨 ᔼ ᨨ   鼀 �鼀盐鼀 ᨨ犨ᆠ  � ᨨ  犨ᨨ├ 盐ᨨ R� W 矄 ᨨ盐   ᲼҈黨黨�和桌

E

R

R

W

㡰 2

R R

R

 黨

㡰 

ᆠ㡰

 

㡰 ҈

Integer Value Answer

҈� 犨ᨨ �矄 ᨨ  �   鼀 矄   �   �   矄�矄 ᆠ矄ᆠᨨ

ᆠ 矄矄 ᨨ犨  ᨨ�ᆠᨨ矄矄 꾀� ᨨ矄�矄 ᲼҈҈桌

黨

W W

W

㡰 ҈꾀 ᨨ鼀턼ᨨ 㡰 ҈꾀 ᨨ鼀ᨨ턼 ᆠ㡰 ҈꾀 ᨨ鼀ᨨ턼 㡰 꾀 ҈҈ ᔼ    ᆠ�ᆠ 犨ᨨ├ 矄 ᨨ犨  犨   ᨨ ᆠ盐  ᨨ犨矄  ᨨ盐�    W 矄�矄ᨨ �    鼀 쟼   ᨨ � �  ᆠ 犨    ᨨ� 矄꾀    犨�   ᲼㝐� 졠 � 꾀�҈҈҈�桌 W



R

R

B W

W



W W

Numeric Answer

҈





3



A

C

 黨W



ᔴ   黨 㡰  㡰  ᆠ㡰 � 㡰  ҈ ᆠ�ᆠ盐�矄 ᨨ犨   矄犨ᨨ�矄ᨨ  ҈   矄�矄ᨨ矄W黨W 黨W ᆠᆠ�ᨨᨨ �m  ᲼㝐� 졠 � 꾀�҈҈桌 ᔼ � m

W

黨W 黨W

 ᔼ҈

҈

҈҈W D

 ᨨ盐矄�矄 ᆠ矄WW黨W ҈҈W鼀├ 鼀矄 ᨨ ⼄盐 �ABCD꾀ᆠᨨ矄矄AC�矄泐ᨨ 鼀   �  矄�矄 ᆠ ���� ᨨ � �  ᆠ ᆠᨨ矄矄BD� �矄힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌 ҈䰘 꾀 � ᆠᨨ 鼀 ҈�矄ᆠᨨ

ᆠ � ᆠ�ᆠ盐�矄 ᨨ犨 �

��盐쟼ᆠ 矄�矄 ᆠ�矄W ᨨ � �  ᆠ �

㡰 ᆠᨨ矄矄   ᆠᆠ�ᨨ 犨   � �矄 盐泐ᆠ �  �矄 힘힘힘힘힘힘힘힘힘힘 [Main Sep.02, 2020 (II)]

ᔼ

ᨨ犨鼀盐ᆠ �矄 ᆠ盐 ᔼ�  ᆠ�ᆠ盐�� 矄 泐矄䁸 㡰 ҈꾀 㡰 䰘꾀 ᆠ㡰 �꾀 㡰 �꾀 ҈ 꾀犨�ᨨ  � L  �  �ᆠᆠ矄ᨨ  �����   矄�矄 ᆠ矄ᆠᨨ

ᆠ �  矄�矄 盐ᨨ ᆠ盐   鼀盐ᨨ  犨��矄�矄 泐DT� �鼀t꾀

盐鼀N ᨨ 矄�鼀�ᆠ矄�矄 ᨨ犨ᆠᨨ

ᆠ � 矄�矄犨� 

҈ 



ᔴ � 

҈

WWW.JEEBOOKS.IN

P-185

Current Electricity

5 ҈

㡰 㡰 ᆠ㡰 㡰

True / False

ᔼ  ᆠᨨ泐�ᆠ矄ᨨ盐�ᨨ  ᆠ�ᆠᆠ盐 �矄鼀� 泐 盐ᨨ 鼀ᨨ鼀 ᨨ  ᆠᨨ 矄 ᲼҈黨桌 6

10 Subjective Problems

MCQs with One or More than One Correct Answer

҈黨 犨ᨨ� �矄ᨨ 鼀 V҈ V  矄�矄 ᆠ矄 R҈R Rᆠᨨ

ᆠ 矄矄 ᨨ犨 �   ��盐  ᆠ盐 � 矄�矄 ᆠR犨ᨨ盐  ᨨ� ᲼꾀 ҈桌





ᆠ盐  ᨨ盐� 턼�矄 ᨨ ᔼ҈㦨꾀

ᨨ �和�矄矄矄   턼 ᔼ㦨꾀

҈ ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐쟼 ෌ᆠ矄ᨨ 鼀 ҈  ҈ᨨ矄ᆠ�泐  ��  矄�矄 ᆠ矄 ҈ ҈ᨨ 鼀矄ᆠ�泐 ᲼҈黨㜠㝐├矄桌 ᔴᆠ盐 �㡰  ᨨ � �  ᆠ犨   ��㡰  ᨨ � �  ᆠᆠᨨ矄矄 鼀� 矄ᨨ ᆠ ᆠ矄෌ 

R

E B

A

V

W

F

R 㡰 V҈㦨V R҈㦨R㦨R 㡰 V҈㦨V R҈㦨R㦨R ᆠ㡰 V҈㦨V R҈㦨R㦨R 㡰 V҈㦨V R҈㦨R㦨R  ᨨ 矄�矄 ᆠ 犨ᨨ├矄 ᨨ犨 �   ��盐ᆠ ᨨᨨ矄  ᆠᨨᆠᨨ�ᨨ 矄㡰 ᲼҈㜠ᔼ桌

H C

D

G

 ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��E҈㦨ᨨ矄E㦨ᨨ矄E㦨҈ ᨨ  㦨r҈㦨r㦨r㦨҈ᨨ 鼀 ᲼҈黨҈㜠㝐├矄桌 r҈ 졔 

A

R

�҈ ᔴ �

�

r r

E҈ 졔  E 졔  E

B D

�㡰

�  ᨨ � �  ᆠ犨  ᨨ� 矄A  B  ᆠ盐 矄 ᨨ盐� ᆠ  ᆠ  ��㡰 ᔼ r�矄矄 ᨨᆠ�ᆠ盐�   ᨨ� A�矄ᆠᨨ

ᆠ ᨨ ᨨ� B �  ᆠ盐 矄 ᨨ盐� E҈EE   矄�矄ᨨR



Topic-4 : Heating Effect of Current 1 ҈





MCQs with One Correct Answer

꾀 ᆠ�ᆠᨨ犨�  � �ᨨ矄�矄 ᆠᨨ W �矄҈├␔  �ᆠ� ᆠ泐ᨨ   矄鼀�矄矄�ᨨ

� �矄ᨨ �鼀泐 ᲼㝐� 和� ᔼ㡰桌 㡰 䰘奠 㡰 黨҈奠 ᆠ㡰 �奠 㡰 黨奠 ᔼ 盐� � � ҈�盐矄ᨨ �␔҈�盐矄ᨨ ҈␔ ҈�矄鼀  矄ᨨ ҈␔  矄ᨨ ҈├␔ ᨨ� ᨨ ᆠ�ᆠ鼀� �矄 鼀� �鼀盐鼀 盐矄ᆠᆠ�泐  盐㡰ᨨ  盐� � �犨� ᲼㝐� 䰘  ᔼᔼ㡰桌 㡰 ҈꾀 㡰 �꾀 ᆠ㡰 ҈�꾀 㡰 꾀

矄�矄� 犨ᨨ├矄 ᨨ犨 ᨨ犨�矄ᆠᨨ

ᆠ ᨨᔴ 矄ᨨ盐ᆠᨨ ҈ ᨨ犨ᆠᨨ 矄盐鼀 泐  犨ᨨ├�矄 ␔ 盐ᨨ  �矄 ᲼㝐� ҈꾀҈黨 ᔼ㡰桌



㡰 W 㡰 W ᆠ㡰 ҈W 㡰 ҈W 졠 ├�ᨨ 犨ᨨᔴ�矄  �  ᆠ�ᆠ├ 犨 ᨨ矄 � �鼀  矄鼀  鼀盐� 㡰 矄�矄 ᆠᨨ W 鼀矄ᨨ��  鼀� 矄�矄 ᔼ� ᨨ� � ᨨ矄矄 ᨨ鼀 ├�鼀├  ᨨ犨ᨨ ᨨ 盐泐�矄ᆠᨨ矄ᨨ ᲼和ᆠ� �ᆠ ᨨ 犨㦨⏌ ├�ᨨᔴ㡰  ᨨ 犨 㦨├⏌├�桌 ᲼㝐� ҈꾀҈黨 ᔼᔼ㡰桌 㡰 ҈鼀� 盐矄 㡰 鼀� 盐矄 ᆠ㡰 鼀� 盐矄 㡰 鼀� 盐矄

WWW.JEEBOOKS.IN

EBD_8341 P-186

5.

6.

7.

8.

Physics

Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage source. If the 25 W and 100 W bulbs draw powers P1 and P2 respectively, then: [Main 12 Jan. 2019 (I)] (a) P1=16 W, P2=4 W (b) P1=16 W, P2=9 W (c) P1=9 W, P2=16 W (d) P1=4 W, P2=16 W Two equal resistances when connected in series to a battery, consume electric power of 60 W. If these resistance are now connected in parallel combination to the same battery, the electric power consumed will be : [Main 11 Jan. 2019 (I)] (a) 60 W (b) 240 W (c) 120 W (d) 30 W A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is: [Main 10 Jan. 2019 (II)] (a) 11 × 10–5 W (b) 11 × 10–3 W (c) 11 × 10–4 W (d) 11 × 105 W The figure shows three circuits I, II and III which are connected to a 3V battery. If the powers dissipated by the configurations I, II and III are P1, P2 and P3 respectively, then : [Main Online April 9, 2017]

12. Which of the four resistances P, Q, R and S generate the greatest amount of heat when a current flows from A to B? [Main Online April 23, 2013] P = 2W

Q = 4W

A

B

R = 1W

S = 2W

(a) Q (b) S (c) P (d) R 13. Incandescent bulbs are designed by keeping in mind that the resistance of their filament increases with the increase in temperature. If at room temperature, 100 W, 60 W and 40 W bulbs have filament resistances R100, R60 and R40, respectively, the relation between these resistances is [2010] 1

(a)

R100

=

1 1 + R40 R60

(b) R100 = R40 + R60 1

1W

1W

1W 1W

1W

3V

1W

1W

1W

1W

3V 1W

1W 1W

(I)

1W

1W

1W

3V

(II)

(a) P1 > P2 > P3 (c) P2 > P1 > P3

(b) P1 > P3 > P2 (d) P3 > P2 > P1

9.

1 1 > R100 R60 R40 14. Figure shows three resistor configurations R1, R2 and R3 connected to 3V battery. If the power dissipated by the configuration R1, R2 and R3 is P1, P2 and P3, respectively, then – [2008]

(c) R100 > R60 > R40

1W

>

(d)

(III)

R

3V

3V

R

r

R1

In the circuit shown, the resistance r is a variable resistance. If for r = fR, the heat generation in r is maximum then the value of f is : [Main Online April 9, 2016] 1 1 3 (a) (b) 1 (c) (d) 2 4 4 10. In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of electric mains is 220 V. The minimum capacity of the main fuse of the building will be: [Main 2014] (a) 8 A (b) 10 A (c) 12 A (d) 14 A 11. Four bulbs B1, B2, B3 and B4 of 100 W each are connected to 220 V main as shown in the figure. [Main Online April 19, 2014]

(a)

P1 > P2 > P3

(b)

P1 > P3 > P2

R2

3V

(c) P2 > P1 > P3 (d) P3 > P2 > P1 R3

15. The three resistance of equal value are arranged in the different combinations shown below. Arrange them in increasing order of power dissipation. [2003S] i

220 V

B1

B2

B3

B4

i

Ammeter

The reading in an ideal ammeter will be: (a) 0.45 A (b) 0.90 A (c) 1.35 A

(d) 1.80 A

(I)

(II)

WWW.JEEBOOKS.IN

P-187

Current Electricity

ᆠ㡰   �盐矄ᨨ  犨��矄 ᨨ盐  㡰   � ᨨ  犨��矄 ᨨ盐   �

҈



ᔼᔼᔼ㡰 ᔼ㡰 㡰 ᔼᔼᔼᔼᔼᔼᔼ 㡰 ᔼᔼᔼᔼᔼᔼᔼ ᆠ㡰 ᔼᔼᔼᔼᔼᔼᔼ 㡰 ᔼᔼᔼᔼᔼᔼᔼ 꾀҈ ␔盐B҈  犨ᨨ ␔盐B   B  ᆠᨨ

ᆠ ᨨ�矄ᨨ盐ᆠ矄矄 ᨨ犨 �  ��盐ᨨ犨W҈ W W ᨨ盐盐ᨨ犨矄ᨨ  盐矄B҈B B矄ᆠ�泐 

᲼和桌 B2

B1

B3

�

҈䰘

㡰 W҈> W㦨 W 㡰 W҈>W>␔ ᆠ㡰 W҈ W㦨 W 㡰 W҈WW ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��  ᨨ 盐ᆠ �  �ᨨ 鼀 矄�矄ᨨ 盐ᨨ ᆠ盐  ᨨ犨� � ᨨ盐� ��矄҈ᆠᨨ�矄  矄ᆠᨨ  ᲼҈黨҈㜠㝐├矄桌 W 6W

5W

҈

 �  �  ᨨ 鼀矄矄�矄ᨨ�矄 㡰 ҈ᆠᨨ�⏌矄ᆠ 㡰 ᆠᨨ�矄⏌矄ᆠ ᆠ㡰 ᆠᨨ�矄⏌矄ᆠ 㡰 ᆠᨨ�矄⏌矄ᆠ 꾀ᆠᨨ 矄 ᨨ��矄� 犨  犨ᨨ 矄ᨨ  盐 � ᨨ鼀鼀�ᆠ犨�和ᨨ鼀 �矄 ᨨ � �   ᨨ �矄 ᨨ盐 � ᲼҈黨桌 㡰 ᨨ   �    �盐矄ᨨ  犨�   㡰 ᨨ   �    �盐矄ᨨ  犨� ᨨ盐 

2

Integer Value Answer

҈黨 ␔  犨ᨨ�  �ᆠ�矄ᨨ �  矄�矄 ᆠ҈Wᆠ ᆠᨨ

ᆠ � 矄�矄ᆠᨨ矄矄矄�矄ᨨR ᨨ   ᨨ 盐ᆠ �  �矄J҈␔   矄鼀�矄ᆠᨨ

ᆠ � ᆠᨨ矄矄  �矄Jᔼ J҈㦨�J    盐ᨨ R� W�矄 ᲼҈桌 4

Fill in the Blanks

 꾀 ᆠ�ᆠ盐  ᨨ�犨矄҈ᨨ矄�矄盐矄 �

ᆠ�ᆠ盐� � �ᨨ矄矄盐泐 矄�矄 ᆠR  鼀盐矄盐� 矄�矄犨�  盐矄ᨨ  盐 �矄 �犨�矄ᨨ 鼀 ᲼҈黨䰘㜠㝐├矄桌 6 MCQs with One or More than One Correct Answer ҈ ᨨ  ᆠ�ᆠ├�矄鼀 ᨨ 犨�ᨨ  � L �鼀dᔼ├矄鼀� 盐矄ᨨ�矄 鼀盐ᨨ �├�犨泐⧤ �矄 �矄ᆠ 泐 犨  � �犨ᨨ犨�矄ᨨ  矄鼀鼀�ᆠ ᨨ  � L  �鼀d 犨泐 矄犨�矄ᆠᨨ

ᆠ �矄 �� �  ᨨ�ᨨ 矄ᨨ犨鼀盐ᆠ �鼀� 鼀� 盐矄犨��├ ᨨ�矄 鼀盐ᨨ  矄鼀鼀ᨨ盐 ᨨ 犨泐 ᲼꾀 ҈桌 K䁸 㡰 � 犨�矄�  㡰 � 犨�矄� 矄�矄 ᆠ㡰 ҈� 犨�矄� 矄�矄 㡰 �� 犨�矄�  10 Subjective Problems  꾀 �矄 矄��  ᨨᨨ犨� ᨨ犨ᨨ ҈犨矄 � ҈ᨨ� ᔼ�矄ᆠᨨ

ᆠ � ᆠᨨ鼀� �ᨨ 矄犨�  矄�矄 ᆠᨨ ҈ᨨ 鼀矄 矄�矄 ᆠRᨨ҈ᨨ矄 鼀� 矄矄矄 ᨨ犨 �   ��盐␔ 矄 ᨨ盐  盐ᨨ R矄ᨨ   ᨨ矄犨� ᨨ犨ᨨ �犨矄 ᲼҈黨䰘桌  ҈W R

҈

Topic-5 : Wheatstone Bridge and Different Measuring Instruments 1 ҈



MCQs with One Correct Answer

犨ᨨ矄�矄ᨨ矄W Wᆠᨨ

ᆠ � 矄�矄ᆠᨨ矄矄    泐  ᨨ � �  ᆠ 鼀矄盐  泐  ᨨ鼀ᨨ ҈├Wᆠᨨ矄矄W矄�矄ᨨ�矄ᆠᨨ矄ᨨ ᲼㝐� 和 ᔼᔼ㡰桌 㡰  㡰 ҈ ᆠ㡰 � 㡰 ҈黨� ␔ �ᆠ  ᨨ    ᨨᨨ犨� � 犨� 졠   ᨨ矄  犨    鼀盐�鼀 ᨨ� �� 矄�矄 ᆠ鼀矄盐� �鼀ᨨ 㡰ᨨ矄 ᆠᨨ

ᆠ ᆠᨨ矄矄ᆠᨨ鼀ᨨ  盐矄矄 䁸 ᲼㝐� 和 ᔼᔼ㡰桌

㡰 㝐盐�鼀矄 ᨨ犨矄 ⼄盐  ᆠ�ᨨ � ᨨ ᆠ矄矄 � ᨨ  矄� � ᨨ矄�  ᆠ ᨨ矄

ᆠᨨ鼀ᨨ  �矄矄�矄ᨨ 㡰 㝐盐�鼀 矄 ᨨ犨矄 졠  ᆠ�ᨨ  �  ᨨ  ᆠ矄矄 �  ᨨ    矄� � ᨨ矄�  ᆠ ᨨ矄

ᆠᨨ鼀ᨨ  �矄ᆠᆠ�ᨨ ᆠ㡰 㝐盐�鼀 矄 ᨨ犨矄   ᆠ�ᨨ  ᆠᆠᨨ鼀 �  泐 矄矄 ᨨ �� ᨨ盐ᨨ ᆠᨨ

ᆠ  졠  ᆠ�ᨨ ᨨ

矄� � ᨨ矄�  ᆠ ᨨ矄 ᆠᨨ鼀ᨨ  �矄쟼 㡰 㝐盐�鼀 矄 ᨨ犨矄 졠  ᆠ�ᨨ  �  ᨨ  ᆠ矄矄 �  ᨨ    矄� � ᨨ矄�  ᆠ ᨨ矄

ᆠᨨ鼀ᨨ  �矄鼀犨�

WWW.JEEBOOKS.IN

EBD_8341 P-188



Physics

J

P

Q

r



�

ᆠᨨ

ᆠ   � 꾀犨 �ᆠ  � ᨨ鼀矄 矄 ᨨ犨  �  �� 矄 ᨨ犨矄 ᨨ  ᆠ�ᨨ  �矄 ᲼㝐� ҈ ҈黨 ᔼ㡰桌

꾀ᨨ �ᨨ鼀犨�PQᨨ ҈鼀 � �矄ᆠᨨ

ᆠ ᨨ 矄  ᆠE҈꾀 ᨨ ᆠEᨨ 鼀 ҈�矄ᆠᨨ

ᆠ 犨� 矄�矄 ᆠἘrἘ 矄犨�ᆠ S 矄矄 ᨨ犨 �  ��盐㡰␔� 矄犨�ᆠ Sᨨ   盐ᨨ矄��ᨨ �矄ᨨ�   �矄 ᆠᨨ 黨ᆠ鼀 ᨨ鼀Q ᨨ �� � �  ᨨ �ᨨ鼀 犨��矄 [Main Sep.02, 2020 (II)] E҈

G

E S 㡰 ⏌ᆠ鼀 㡰 ҈⏌ᆠ鼀 ᆠ㡰 ⏌ᆠ鼀 㡰 ⏌ᆠ鼀

 � ᨨ ᨨ �ᨨ鼀犨��矄҈ᆠ鼀 �ᆠ�矄 ᆠ盐 ᨨ 鼀꾀 ᨨ ᆠᨨ 鼀 � �   矄�矄 ᆠᨨ W  盐ᨨ� ᨨ ��矄 ᨨ盐 ᨨ ҈ᆠ鼀 矄�矄 ᆠᨨ 犨 ᨨ犨��矄 ᲼㝐�   ᔼ㡰桌 㡰 W 㡰 ҈W ᆠ㡰 W 㡰 ҈W ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨  ᨨ盐㜠犨�ᨨ �ᨨ鼀�矄鼀 ᨨ ᆠ鼀ᨨ �犨�犨 �ᆠ   矄犨 꾀   矄�矄 ᆠ  盐 �  �  ᨨ   ᨨ �ᨨ鼀 犨� �矄 r㦨҈W⏌ᆠ鼀ᔼ  � ᨨ鼀�矄ᆠᨨ

ᆠ 矄矄 ᨨ犨

犨� ᨨᆠ├泐�ᆠ鼀 ᨨ鼀 꾀  ᆠ  � �ᨨ  ᨨ鼀犨� ᲼㝐� 꾀҈黨 ᔼᔼ㡰桌

҈҈ ҈҈ ҈ �     㡰 ᆠ㡰 㡰 ҈   ҈

␔ 矄ᨨ � �矄 ᨨ犨 �  �� �矄 ᆠ 犨   ᆠᨨ 矄�矄ᨨ盐矄 矄 ҈ 矄 ᆠᨨᨨ盐 ᆠᨨ  졠 �  ᨨ犨 㡰 矄�矄ᨨ矄   W  W矄ᆠ�泐 꾀矄矄盐鼀� �     ᆠᨨᨨ盐 ᆠᨨ  ᨨ   ᆠᨨ  矄�矄ᨨ矄 ��矄 �ᆠᆠ盐盐矄 ᆠᨨᨨ盐ᆠᨨ  ᨨ ᆠᨨ

矄�矄ᨨ盐矄 矄 犨ᨨ盐 ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌

㡰





҈ ෌ 









㡰 � 㡰 䰘� ᆠ㡰 � 㡰  ᔼ ␔ 矄ᨨ � � 矄 ��㡰 矄�矄 ᆠ矄 턼 ᨨ �鼀泐⼄盐␔   㦨W � ��矄 ᆠ  졠 � ᆠ  �� � 턼 盐ᨨ   ᨨ ᆠ�矄 �W 盐ᨨ �矄ᆠᨨ矄ᨨ᲼㝐� ҈҈ ҈黨 ᔼ㡰桌  턼

 ෌ 꾀

⧤



㡰 ᨨ犨 盐ᨨ犨 㡰 ᨨ犨 盐ᆠ├ ᆠ㡰  ෌ ᨨ犨

㡰 ෌泐ᆠ├ᨨ犨

黨 ᔼ ᨨ �ᨨ鼀 �鼀 ��矄 ᨨ盐   ᨨᆠ盐  矄矄矄 ᨨ盐�  � ᨨ鼀犨   鼀� 矄ᨨ  ᆠᆠᨨ

ᆠ ᆠᨨ矄矄�ᆠ鼀ᨨ  ᨨ �ᨨ鼀 犨�ᔼ  ᆠ�矄矄 盐  泐矄�矄 ᆠᨨ �W ᆠ �矄 ᨨ盐 犨   ᆠ�矄ᆠᨨ

ᆠ ᆠᨨ矄矄ᆠ鼀 ᨨ   犨� �  �  矄�矄 ᆠᨨ  ᆠ ᲼㝐� ҈桌 㡰 ҈W 㡰 ҈�W ᆠ㡰 W 㡰 �W ҈ ᔼ 鼀� �矄矄 ᨨ犨 �   ��盐��矄��   矄�矄 ᆠӸ㦨҈�W    ᆠ�矄ᨨ�   �矄 ᆠ 黨� ᆠ鼀 ᨨ鼀   A 泐 ᨨᆠ├泐 㡰 꾀  � ᆠ  �� � 矄�矄 ᆠ矄X Y 犨 ᆠᨨ�  �矄 ᨨ盐  �矄 ᆠl ᨨ鼀 A␔  盐矄ᨨ X l䁸 ᲼㝐� 졠 � 꾀�҈�҈桌 





෌ 꾀

⧤҈

䰘

Ӹ 

㡰 ҈�ᨨ 鼀 㡰 �ᨨ 鼀 ᆠ㡰 �ᨨ 鼀 㡰 �ᨨ 鼀 꾀ᨨ �ᨨ鼀犨�꾀 � � �  矄�矄 ᆠ ҈�矄ᨨ�  ᨨᆠᨨ 鼀 e �  矄�矄 ᆠ 꾀ᆠᔴ � � 鼀 e⏌ �   矄�矄 ᆠ �矄



҈ l҈㡰



黨�  犨�



㝐쟼 쟼 和ᔴ꾀쟼

泐

㡰 ҈黨҈�W 黨�ᆠ鼀 ᆠ㡰 ҈黨҈�W �ᆠ鼀

⧤泐

㡰 ҈W �ᆠ鼀 㡰 ҈W 黨�ᆠ鼀

WWW.JEEBOOKS.IN

P-189

Current Electricity

҈҈ ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 矄䁸᲼㝐� ҈䰘桌 㡰 꾀 ᨨ矄ᆠ 盐矄 矄ᨨ � ��  㡰 ⧤�ᆠ ᨨ Ἐ矄矄ᆠᨨ 犨矄 矄 �泐ᆠᨨ 矄�ᨨ

ᆠ㡰 ␔ 矄ᨨ � ��矄 鼀ᨨ矄矄 矄��犨    ᨨ盐矄�矄 ᆠ矄ᨨ  矄鼀ᨨ ᨨ 鼀� �盐  㡰 ᔼ    ᆠ  犨 矄ᨨ � � �    ᆠ     � ᨨ鼀 ᆠ  �   盐ᨨ� �矄 �矄盐  ҈ 꾀҈泐犨� �  矄�矄 ᆠ҈W ҈�泐 犨� �  矄�矄 ᆠW ᆠᨨ

ᆠ � ᨨ ᨨ鼀 矄 ��盐㡰  � ��  ᨨ鼀犨� ᆠᨨ矄ᨨ  ᲼㝐� 졠 � 꾀�҈҈�桌 ҈ ҈W

�␔   矄矄�矄 ᆠ矄� ᆠ  �   ᆠ ᨨ�  矄 � 矄 泐ᆠ鼀 �ᆠ� �  泐ᆠᨨᆠ�ᨨ 矄   ᲼䰘桌 盐 ├ ᨨ犨 矄�矄 ᆠ�矄 㡰 W 㡰W ᆠ㡰 �W 㡰W ҈ 꾀鼀ᨨ� �ᆠᨨ�� ᨨ鼀ᨨ 矄�矄 ᆠ҈W�矄盐矄 矄   鼀鼀 盐矄� � 矄�矄 ᆠ҈ W.   鼀 �鼀盐鼀  ᆠ�ᨨ ᆠ盐 �  � ᨨ鼀�矄҈m꾀 �   鼀� �鼀盐鼀ᆠ盐 �  ᆠ�ᆠ盐�矄ᨨ  鼀鼀矄 ᨨ犨矄 鼀 �鼀盐鼀  ᆠ�ᨨ

᲼�和桌 㡰 ҈҈鼀꾀 㡰 ҈҈鼀꾀 ᆠ㡰 ҈҈鼀꾀 㡰 ҈҈鼀꾀 ҈䰘 ᔼ  矄 ᨨ犨  �鼀 ᨨ   �鼀 ᨨ  鼀 � � �  AC ᆠᨨ矄ᨨ � � ᨨ 盐  ᆠ�ᨨ  ᨨ � ᨨ鼀�矄 犨 犨ᨨ盐 �矄盐�   �盐矄ᨨ  犨�꾀�矄 ᨨ盐 䁸 ᲼和桌

҈� W

R

R҈ G



㡰 ҈� 㡰 � ᆠ㡰 ҈҈ 㡰 ҈҈黨 ҈ 盐� �  �鼀 犨� 鼀� � � ᨨ鼀 矄 ᨨ犨矄 盐ᨨ� 犨   ᨨᆠ├泐�矄矄矄 ᆠ鼀 盐矄� �矄  矄�矄 ᆠᨨ 黨W矄矄 ᨨ犨 �   ��盐

矄ᆠᨨ盐  ᨨ  矄ᆠ盐矄 �  鼀� ��矄 ҈鼀鼀 盐 ├ ᨨ犨 矄�矄 ᆠ�矄 ᲼꾀 ҈桌



黨W

A

㡰 x

x

㡰 x⏌

B

C

ᆠ㡰 x

҈ ᔼ  ᆠ�ᆠ盐� P ¹ R   � � ᨨ  � ᨨ鼀�矄矄鼀犨� 矄犨�ᆠ Sᨨ ᨨᆠᨨ矄  

᲼҈黨黨黨㜠㝐├矄桌 㡰 IR㦨IG 㡰 IP㦨IG

㡰 x

Q

P S R

G



ᆠ㡰 IQ㦨IG 㡰 IQ㦨IR

㡰 ҈

ᆠ鼀  ± ҈� W

3 㡰 ҈� ± � W

ᆠ㡰  ± � W 㡰 ҈� ±  W 꾀鼀� ��矄矄盐矄矄 ᨨ犨 ᨨ 鼀�  盐 ├ ᨨ犨

矄�矄 ᆠ � 盐矄� �  矄   ҈ ᨨ 鼀 矄�矄ᨨ  � ᨨ鼀矄 ᨨ犨矄 盐ᨨ� 犨  � �㜠├泐�矄� ᆠ鼀 鼀├   㜠ᆠᨨᆠ�ᨨ 矄  ҈ ᆠ鼀    ᆠ鼀 矄ᆠ�泐 ᨨ  矄꾀   鼀�  盐 ᨨ ��矄 ᲼҈҈桌

 㡰 ҈ᨨ 鼀 㡰 ҈ᨨ 鼀 ᆠ㡰 ҈ᨨ 鼀 㡰 ҈҈҈ᨨ 鼀 ҈� 꾀矄�矄 ᆠᨨ W�矄ᆠᨨ

ᆠ ᆠᨨ矄矄ᨨ �ᨨ 鼀㜠 � �   � ᨨ  犨��矄҈ᆠ鼀㡰  盐 ├ ᨨ犨

矄�矄 ᆠ�  W�矄ᆠᨨ

ᆠ ᆠᨨ矄矄 ᨨ 

V

Numeric Answer

 ᨨ盐矄�矄 ᆠ矄ᨨ ҈�W҈WW ҈W矄ᆠ�泐 �  ᆠ泐ᆠ�ᆠ ᨨ  ᨨ ᨨ鼀 ␔ 矄ᨨ 矄 犨ᨨ├  矄�矄 ᆠ   �矄 ᨨ  ᆠᨨ

ᆠ  �   犨�    矄�矄 ᆠᨨ ҈Wᨨ ᆠ  犨ᨨ├�矄힘힘힘힘힘W ᲼㝐�   ᔼ㡰桌   ᆠ� � �  ᨨᆠ�矄�ᆠ鼀� ᨨ �ᨨ鼀  �鼀  ␔        矄�矄 ᆠ ᨨ  ҈ W �矄 ᆠᨨ

ᆠ  �   ᨨ   ᆠ    ᆠ� �  � ᆠ  �矄泐ᆠ鼀ᔼ  �  矄�矄 ᆠᨨ  ᆠ�矄 N W犨 �矄 � �  盐ᨨ �矄________ ҈ ᲼㝐� 䰘  ᔼᔼ㡰桌 � ᔼ   ᆠ ᆠᨨ ��ᨨ  盐矄ᨨ  矄�矄 ᆠ矄ᨨ   ᨨ盐鼀矄ᨨ ␔ 矄ᨨ � �矄 ᨨ犨 �   ��盐ᨨ犨 矄�矄 ᆠR 矄鼀盐ᆠᨨ �ᆠ�   ᔴ҈ᔼ  鼀盐ᨨ R�矄� ᆠ矄 泐҈ ᔴ  ᨨ� ᨨ 犨 S T犨�힘힘힘힘힘힘힘힘 ᨨ ᲼꾀 桌

WWW.JEEBOOKS.IN

EBD_8341 P-190

Physics

AB ᔴ � 犨 �ᆠ ᨨ  ᨨ犨��� 鼀ᨨ矄 ᆠᆠ盐 � � 犨 泐䁸 ᲼�㜠㝐├矄桌

V

R҈㦨W

R㦨҈W

P

�

X R㦨W

S

R㦨�W

T

A Q

Assertion and Reason Type Questions

9 

和T꾀TE㝐ENT㜠҈ᔼ 㝐� � �鼀  盐ᨨ�  ᨨ 盐 ├ ᨨ犨 矄�矄 ᆠ�矄鼀矄盐 ᨨ犨 盐 ├ ᨨ犨

矄�矄 ᆠ�矄盐� 矄�   ᆠᨨ矄盐鼀� �   ��  鼀盐  盐ᨨ� ᆠ ᨨ�   矄鼀 ᨨ�  矄 ᨨ泐 ᆠ矄� � 盐ᨨ  矄  矄�矄 ᆠ 和T꾀TE㝐ENT㜠 矄�矄 ᆠᨨ 鼀� ᆠ矄矄犨� � ᆠ矄� 鼀盐 ᲼桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐

B

C

 꾀  �  盐 � ᨨ鼀 犨� AB ᨨ   �  ҈鼀   盐 ├ ᨨ犨

矄�矄 ᆠX 矄�矄 ᆠᨨ ҈Wᆠᨨ

ᆠ 泐  �ᆠ├ᆠᨨ 盐ᆠ� �矄�矄矄矄 ᨨ犨 �   ��盐꾀泐  � ᨨ鼀 犨� 矄� � �ᨨᆠ├泐ᆠᨨ

ᆠ ᨨ �㡰  矄ᨨ � ᔴᨨ

ᆠ�ᨨ 矄  ᨨ  鼀  ᨨ 鼀矄盐 盐 ├ ᨨ犨 矄�矄 ᆠX盐矄� � � ᆠ�ᨨ ␔ 矄ᨨ � �꾀 矄犨  ᨨᨨ犨� �⼄盐矄�ᨨ 矄 ᲼㜠�㝐├矄桌

҈W

X A

B

C

D

㡰 꾀   ᨨ矄��   �� 鼀� 矄 ᨨ    � ᨨ鼀䁸 㡰 ᔴᨨ泐  ��盐� 泐ᨨ盐 矄犨ᨨᨨ├ 矄 ᨨ犨  泐     � ᨨ鼀 犨�  ᨨᆠ├泐㡰 ᆠᨨ

ᆠ ᨨ�ᨨ� 矄

10 Subjective Problems 䰘

R㦨R҈ᨨRᨨR

R G

꾀  盐 ├ ᨨ犨  矄�矄 ᆠ X �矄 ᨨ  鼀�   盐矄� � 矄�矄 ᆠ矄R҈RᨨR �ᆠᨨ矄ᨨ � � 盐ᨨ� 矄

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈

㡰 㡰 ᆠ㡰 㡰

MCQs with One Correct Answer

1

꾀 ᆠ�ᆠ盐� �矄ᆠᨨ

ᆠ  矄矄 ᨨ犨  �    ��盐犨�    矄犨�ᆠ Sᨨ ␔   矄犨�ᆠ �矄ᆠᨨ矄  ᨨ鼀ᨨ盐  ᨨ ᆠ �  ᨨ犨矄 ᨨ鼀YᨨX�矄 ᲼䰘桌 mF

m F

X



S W

W



Y

黨



㡰  㡰 �mᔴ ᆠ㡰 䰘mᔴ 㡰 ҈mᔴ ᔼ 矄 泐ᆠ盐 ᔼ�矄 ᨨ犨� � ᨨ盐� ᆠ泐� �ᆠ鼀  꾀ᔴᔴ ᨨᨨ矄 ᆠᨨᆠ�ᨨ 矄 � ᲼桌 A

B

r

r

I

l⏌

C

�

V AB = VBC

ᨨ犨ᆠᨨ矄矄BC�矄�鼀矄 ᨨ犨ᆠᨨ矄矄AB ᔴ盐   矄��矄� AB BC⼄盐 쟼ᆠ�ᆠ �  盐ᨨᆠ盐 � 矄� AB BC ⼄盐 꾀 � �矄�矄 � � ᆠᨨ矄 ���   鼀泐� 矄盐 ᆠᨨ � 꾀ᆠᨨ�ᨨ ҈W矄�矄ᨨᆠ泐� �ᆠ盐 ҈꾀 ᨨ �鼀� 盐矄矄盐�矄 ᨨ �矄 ᆠ  �� �    �泐ᨨ  �矄�矄 ᲼�和桌 㡰 ҈├ 㡰 ├ ᆠ㡰 ├ 㡰 ├ 꾀mFᆠᆠ�ᨨ矄�矄 ᆠᨨ �MW�矄� 矄�矄犨� ҈ 泐 �    �鼀    犨 �ᆠ    ᨨ � �  ᆠᆠᨨ矄矄  ᆠᆠ�ᨨ �矄  �鼀矄  ᨨ � �  ᆠᆠᨨ矄矄 矄�矄ᨨ᲼෌� n 㡰㦨黨桌᲼�和桌 㡰 ҈矄 㡰 黨矄 ᆠ㡰 䰘矄 㡰 ҈矄 꾀ᆠᆠ�ᨨ�矄ᆠ � 盐矄� �   泐犨�  矄�矄 ᆠx� 矄�矄  矄  � 矄 ᨨ犨矄 ��ᨨ

ᨨ  ᔼ犨� 矄ᆠᨨ�鼀ᔼ  矄�矄 ᆠ�矄ᆠ  � ᨨ x  犨� 犨� ᲼和桌

l⏌

WWW.JEEBOOKS.IN

P-191

Current Electricity

㡰 P 㡰 Q

S R

҈n ᔼ

ᆠ㡰R 

Q

P 㡰 S t 和 ᨨ犨 �  ��盐�矄ᨨ矄졠 �ᆠᨨ ᔼ ᨨ ᨨᆠᆠ盐  盐ᨨ   矄�矄 ᆠ�矄 ᨨ盐 ᆠᨨ

ᆠ ᲼和桌 犨

C B A

D

C'

䰘

R �

R ҈

Integer Value Answer

҈ 꾀� ᨨ鼀��矄 盐矄ᆠ  ᆠ�ᨨ 犨� 꾀 ᆠ盐 泐ᆠᨨ

ᆠ� ��ᨨ黨黨W矄�矄 ᆠ�ᆠ  ᆠᨨ  � ᨨᨨ鼀ᨨ  �ᔼ ᆠᨨ

ᆠ n W 矄�矄 ᆠ�ᆠᨨ鼀矄 鼀鼀ᨨ  � ᨨ 黨 ҈�꾀 盐ᨨ n�矄 ᲼꾀 ҈桌 ҈҈ 꾀�鼀t 㦨泐ᨨ ҈�矄ᆠᨨ

ᆠ ᆠᨨ矄矄 ᨨ� 矄꾀 �  �� ᆠ�ᆠ盐�ᔼ  ᆠᆠ�ᨨ矄  ᨨᆠ �� ��泐犨 �鼀 � 矄ᆠᨨ 矄㡰 ᨨ矄  ᨨ�ᆠᨨ矄矄 鼀ᆠᨨ鼀䁸᲼ ├l �㦨҈ l 㦨҈҈桌 ᲼҈桌

R 

R 

m

㝐W

B'

㡰 BἘ CἘ 㡰 A D ᆠ㡰 C D 㡰 B D ᔼ   ��  ᆠ�ᆠ盐���矄 ᨨ矄    ᆠ盐  I �矄 �   ᨨ  盐ᨨ  矄�矄 ᆠR    矄�矄 ᆠ盐矄鼀盐矄矄�矄 泐 ᲼҈和桌

I

2

R 



꾀 㝐W

6

m

MCQs with One or More than One Correct Answer

҈ ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 ᨨ犨 ├泐�矄矄矄 �鼀㦨 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌 m

�├W

R  

㡰 R҈RR�㦨RRR 㡰

㡰 R҈R㦨RR㦨R�R

黨

�W

1 1 1 1 + = + R 5 R6 R1 + R2 R3 + R 4

ᆠ㡰 R҈R㦨RR 



꾀犨�ᨨ  � L  �  �ᆠᆠ矄ᨨ  �����   矄�矄 ᆠ矄ᆠᨨ

ᆠ �  矄�矄 盐ᨨ ᆠ盐   鼀盐ᨨ  犨��矄�矄 泐DT� �鼀t꾀

盐鼀N ᨨ 矄�鼀�ᆠ矄�矄 ᨨ犨ᆠᨨ

ᆠ � 矄�矄犨�  犨�ᨨ  矄鼀鼀� ᆠᨨ矄矄㜠矄ᆠ�ᨨ 盐ᨨ  � L 鼀盐ᨨ  犨��矄�矄 泐 矄鼀鼀ᨨ盐  DT�  矄鼀�鼀t 盐ᨨ N �矄 ᲼҈和桌 㡰  㡰  ᆠ㡰  㡰 黨

ᆠᨨ矄�ᆠ �  盐ᨨᨨ� ᆠ �  矄ᨨ

҈   �矄 ᆠ r 矄   ᔼ �ᆠ 犨 �ᆠ  ᨨ   ᨨᨨ犨� � r ⼄盐 ��矄矄 ᨨ犨矄矄鼀   ᆠᨨ r ᲼҈黨桌 㡰 ᔼ  矄�泐ᨨ ��  ᨨ鼀ᨨ� 矄ᨨ盐ᆠ 㡰 쟼ᆠᨨ矄�ᆠᨨ � 盐ᨨᨨ� ᆠ � ᆠ㡰 쟼ᆠᨨ矄�ᆠᨨ � �矄 ᆠ ᨨ鼀 ᆠ ᨨ ᆠ � 鼀�ᆠ矄 ෌�  r �盐矄ᨨ   矄  㡰 ᨨ ᨨ  矄

 졔 m

졔 ⧤泐



�

㡰

 ᨨ鼀  �矄泐矄 � 矄 矄ᨨᨨ 矄   ├泐 �矄 矄矄   �矄泐矄졔� ᨨ ��鼀 㡰 ᨨ鼀犨� �矄泐�鼀㦨 矄ᆠᨨ 矄 ᆠ㡰 ᆠ盐 �  鼀鼀ᆠᨨ鼀矄҈⏌ᨨ  � �� 盐 ҈矄ᆠᨨ 㡰 ᆠ盐 �  鼀鼀ᆠᨨ鼀矄 ᨨ ᨨ � �鼀 ҈ 꾀 � ᆠ 矄ᆠ 盐 矄 �  �鼀 ᨨ 盐 �矄   �矄   ᨨ ��  鼀盐 泐 矄矄� �   ᆠ�ᆠ ᆠ盐   ᨨ �鼀 鼀�矄ᆠ├ᨨ 泐 ��ᨨ   �鼀 �矄ᨨ矄 ᨨ├盐 ᨨ鼀ᨨᆠ�ᨨ 矄  矄盐 �ᆠ� 泐ᨨ ��鼀ᨨ ᨨ�ᨨ  盐ᨨ ᨨ 盐 � ᨨ鼀 ᨨ�ᨨ ᨨ 盐 �矄  ᨨ鼀  �鼀 ᔼ  盐�矄 ᨨ犨   ᆠᨨ 矄  ᨨ� 犨 �ᆠ  ᨨ    ᨨᨨ犨� � 矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌 㡰 鼀盐 �矄�盐�ᨨ  ᨨ   �鼀  �矄 盐 � ᨨ鼀 㡰 矄�矄 ᆠᨨ矄鼀矄ᆠ�ᨨ 矄ᨨ   �鼀  ᆠ矄矄犨� �鼀 ᆠ㡰  �鼀  鼀�矄 鼀ᨨ��   ��    ᨨ ⼄盐 ᆠ�矄 ᨨ�├矄盐 㡰  �鼀 ᆠᨨ 矄盐鼀矄矄矄ᆠ�ᆠᨨ犨ᨨ犨 矄   ᨨ  � ᨨ  盐

WWW.JEEBOOKS.IN

EBD_8341 P-192

҈

҈�

҈

Physics

␔  ᨨ � �  ᆠ�矄� ᆠᨨ矄矄 ᆠ盐  矄矄� �  ᨨ盐� ᲼҈黨黨黨和㜠㝐├矄桌 㡰  � 矄盐ᨨ⧤�矄 ᨨ 㡰 矄鼀�ᆠᨨ 盐ᆠᨨ⧤�矄 ᨨ ᆠ㡰 鼀⧤�矄 � � 㡰 a p㜠n �ᨨ ⧤�矄 � �� ��矄矄�矄 ᔴᆠ�ᨨC҈ᨨ ᆠᆠ� ᆠ҈鼀�ᆠᨨ㜠   ᆠᆠ�ᨨ Cᨨ ᆠᆠ� ᆠ鼀�ᆠᨨ  矄泐ᆠ �  盐泐 泐  ᆠᨨ鼀鼀ᨨ  泐  犨ᨨ ᆠᆠ�ᨨ矄   

矄泐ᨨ犨 ᨨ �矄ᆠ � ᨨ盐� ⼄盐矄�矄ᨨ矄 �鼀t㦨 ᲼҈黨黨㜠㝐├矄桌 㡰 ᆠ盐 � ᆠ ᨨ  犨ᨨ �矄ᆠ �� �ᆠ�ᆠ盐�矄�矄 ᨨt㦨 㡰 ᆠ盐 矄�  犨ᨨ �矄ᆠ �� �ᆠ�ᆠ盐�矄t㦨 ⼄盐盐 ᨨ ᨨ ᆠ㡰 ᆠ盐 矄�  犨ᨨ �矄ᆠ �� �ᆠ�ᆠ盐�矄t㦨 盐 ⼄盐 㡰 ᔴᆠ�ᨨC҈ᨨ矄矄矄�奠ᨨ �矄� ��ᆠ �矄ᨨᨨ    Cᨨ矄矄�奠ᨨ �矄� ��ᆠ � 7 Match the Following ᔴᨨ盐鼀 ᔼ��矄矄ᨨ鼀 �ᆠ矄 ᔴᨨ盐鼀 ᔼᔼ��矄矄ᨨ鼀 ᨨᆠ矄矄矄 ᨨ  犨 �ᆠ    盐 ᆠ�ᨨ � � ᨨ   矄 �ᆠ矄  㝐ᆠ   �ᆠ矄� ᔴᨨ盐鼀 ᔼ犨�  ᨨᆠ矄矄矄 �  ᔴᨨ盐鼀  ᔼᔼ  � �ᆠ 泐ᨨ盐  矄犨 泐 ├ � � ᨨ�盐矄�  맔鼀� �� �  졠 和

C

A

B

R

 ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐 泐�矄 � ᨨ  犨� 鼀 V ᆠᆠ�ᨨ�矄� ��泐盐 ᆠ �  矄犨�ᆠ S�矄ᆠᨨ矄 �鼀t㦨 ᲼҈黨黨㜠㝐├矄桌 㡰 �  ᆠ �Qᨨ  ᆠᆠ�ᨨ�鼀t 㡰 �  ᆠ盐 � AB�鼀t␔ �矄�矄�鼀�� � 盐矄 t ® ¥  S

R

A

R

V

C

B

R

҈ 꾀 ᆠ�ᆠᆠ�ᆠ盐��矄矄 ᨨ犨 �  ��ᔴᆠ盐 ᨨ � �  ᆠᆠᨨ矄矄 矄�矄ᨨᨨ ᨨ 鼀矄犨�鼀矄盐 泐   ᨨ鼀 V ᨨ  矄�矄 ᆠ  ᨨ 鼀 �  泐 泐� �⧤�ᆠ ᨨ 矄盐矄ᨨᨨ 犨�矄 ᲼҈黨黨㜠�㝐├矄桌

᲼䰘桌 꾀㡰 㡰 ᔴ㡰 㡰

ᔴᨨ盐鼀 ᔼᔼ 㡰  ��ᨨ  ᨨ鼀 ᨨ ᨨ 泐 和鼀 ��  ⼄㡰 쟼 �泐ᆠᨨ 矄�ᨨ

ᔼ ᆠ 矄ᆠ 鼀 㡰 㝐� � 쟼ᆠ�ᆠ 盐矄 矄㡰 鼀  矄�ᨨ ᨨ 矄ᨨ� 矄

V

ᔴᨨ盐鼀 ᔼ �鼀�ᆠ矄�

W

ᔼ  �� ᆠ�ᆠ盐� 矄犨�ᆠ S�矄ᆠᨨ矄 �鼀t㦨  ᆠ � Q ᨨ    ᆠᆠ�ᨨ   泐� 矄  t �矄 ��  泐 Q t㡰㦨Q ҈eat㡰 �  盐ᨨ Q a � 鼀矄ᨨ �� 鼀矄矄矄 ᨨ犨 �  ᆠ�ᆠ盐�᲼�㜠㝐├矄桌 R҈



҈黨

R

᲼҈黨㜠�㝐├矄桌 R҈ =  R 㦨ᨨ 鼀矄

R =  R 㦨ᨨ 鼀矄 C㦨 � m f  �  ᆠ盐 �     �泐矄ᨨ �  ᆠᆠ�ᨨ R҈

C

҈

҈

 ᔼ  �� ᆠ�ᆠ盐� E҈ = E =  E 㦨ᨨ矄

S 졔 

W

҈W



10 Subjective Problems ҈䰘

҈W

҈W l



C

V

犨 ᆠ�ᆠ盐� ��鼀ᨨ� 泐졠 鼀矄犨犨�   ᨨ 鼀� 矄�矄 ᆠᨨ ҈W 犨ᨨ� ᨨ鼀矄 ᨨ 矄�矄 ᆠ矄҈W  ҈W 矄ᨨ盐ᆠᨨ 泐� � 鼀 和 ᨨ犨 ᆠᨨᆠᨨ矄��ᨨ 矄ᨨ ᨨ鼀 鼀鼀 ᲼㜠㝐├矄桌 ᨨ犨  泐�矄 ᨨ  ᆠᨨ

ᆠ  矄ᨨ     矄 ᨨ犨

 ᨨ矄犨� �├ᨨ � �� 䁸꾀矄ᨨ� �ᆠ  ᨨ� 矄ᨨ盐犨 �ᆠ ᨨ盐盐ᆠ ├  ᲼㜠㝐├矄桌

E

R

E

R

R

 꾀ᨨ ᆠ�盐ᆠ盐�� 矄 泐矄ᨨ �犨�  ᆠ盐 矄 ᨨ犨� ��   ᆠ 矄 盐矄ᨨ 矄�矄 ᆠ矄ᆠ�矄 矄 ᨨ犨 �   ��盐ᔴᆠ盐  �泐矄ᨨ �   ᆠᆠ�ᨨC Ҙ 㡰 ᲼҈黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

P-193

Current Electricity

� 和ᨨ 鼀矄犨 ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐ᨨ鼀 矄ᨨ矄 犨  ��矄ᆠᨨ

ᆠ ᆠᨨ矄矄ᨨ 鼀矄�矄 ᆠᔴᆠ盐 犨  矄鼀ᨨ鼀犨� 犨  ��矄ᆠᨨ

ᆠ ᆠᨨ矄矄 ᨨ 鼀矄�矄 ᆠ ᲼҈黨桌

҈꾀 W 

�W

W

꾀 ᔴ

҈W

m 

W

W

҈W

꾀

W

W



W

҈꾀

ᔴᆠ盐 矄 泐矄ᆠ盐 �  㜠ᨨ 鼀矄�矄ᨨ 矄 ᨨ犨 �  ᆠ�ᆠ盐��   ��盐 �  矄�矄 ᆠ ᨨ    泐�矄 ����     ᆠᆠ� ᆠ ᨨ    ᆠᨨ  矄C�矄鼀�ᆠᨨ   ᲼҈黨㜠�㝐├矄桌



W W

 꾀泐ᨨ 鼀 ᨨ矄 �  矄�矄 ᆠ҈ᨨ 鼀�矄 � �ᆠ � 犨� ᆠ盐 ᨨ �鼀矄 ᲼҈黨桌 ᔼ 犨  �ᆠ�ᨨ 犨� ᆠ盐  ᨨ犨� 矄�  泐䁸 ␔ �矄 ᨨ � �  ᆠ犨  犨ᨨ鼀�  ᨨ  泐䁸 䰘 ᔼ   ��鼀矄 ᨨ犨  �  ᨨ � �  ᆠ犨

 ᨨ� 矄A B 犨  ᨨ� 矄B C�   ᲼҈黨䰘黨桌 矄 泐 矄 B

Ҙf Ҙf

W

C

҈Ҙf ҈Ҙf ҈Ҙf

.8 W

҈W

҈

W

C

A

V = 6 VOTS

Answer Key Topic-1 : Electric Current, Drift of Electrons, Ohm's Law, Resistance and Resistivity ҈ ᆠ㡰  㡰  㡰  㡰 ҈҈ ᆠ㡰 ҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈ 盐  矄  ᆠ 㡰 ᆠ㡰

� 㡰 ҈� ᆠ㡰

 ᆠ㡰 ҈ ᆠ㡰

䰘 㡰 ҈䰘 ᆠ㡰

 㡰 ҈ 㡰

黨 㡰 ҈黨 㡰

 㡰

黨 㡰

҈ 㡰  㡰

Topic-2 : Combination of Resistances 㡰

 ᆠ㡰

 ᆠ㡰

 ᆠ㡰

� 㡰

҈҈ 㡰

҈ ᆠ㡰

҈ 㡰

҈ ᆠ㡰

҈� ҈㡰

҈

 㡰

䰘 㡰

҈ 㡰 ҈䰘 㡰

æRö ҈ ç ÷ èø

҈ 㡰

҈黨  㡰  㡰

Topic-3 : Kirchhoff's Laws, Cells, Thermo e.m.f. & Electrolysis ҈ ᆠ㡰  㡰 ҈҈ ᆠ㡰 ҈ 㡰  ᆠ 㡰

 ᆠ㡰 ҈ 㡰

 㡰 ҈ 㡰

� 㡰 ҈� �㡰

 㡰 ҈ 㡰

䰘 㡰  ᆠ㡰 黨 㡰 ҈ 㡰 ҈䰘 㡰 ҈ 矄 ҈黨  㡰

Topic-4 : Heating Effect of Current ҈ 㡰  㡰 ҈҈ ᆠ㡰 ҈ 㡰 ҈  㡰

 㡰 ҈ 㡰

 㡰 ҈ ᆠ㡰

� 㡰 ҈� 㡰

 㡰 ҈ 㡰

䰘 㡰 ҈䰘 ᆠ㡰

 ᆠ㡰 ҈ 㡰

黨 ᆠ㡰 ҈黨 㡰

҈ ᆠ㡰  W㡰

Topic-5 : Wheatstone Bridge and Defferent Measuring Instruments ҈ 㡰  㡰 ҈҈ 㡰 ҈ ᆠ㡰 ҈ 䰘㡰  㡰

 㡰 ҈ ᆠ㡰

 㡰 ҈ 㡰

� ᆠ㡰 ҈� 㡰

 㡰 ҈ 㡰

䰘 ᆠ㡰 ҈䰘 㡰

 㡰 ҈ 㡰

黨 㡰 ҈ 㡰 ҈黨 ҈㡰  ҈㡰

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈ ᆠ㡰 ҈҈ 㡰

 㡰  㡰 ҈ ᆠ 㡰

 㡰 � 㡰  㡰 䰘 ᆠ㡰  㡰 黨 㡰 ҈ �㡰 ҈ ᆠ 㡰 ҈  㡰 ҈�  㡰 ҈ 꾀®矄錐®⼄錐ᔴ®⼄錐®⼄

WWW.JEEBOOKS.IN

EBD_8341 P-194

Physics

Moving Charges and Magnetism

18

Topic-1 : Motion of Charged Particle in Magnetic Field 1 ҈



MCQs with One Correct Answer

꾀 ᆠᨨ �矄鼀ᨨ� �ᨨ �졔x �ᆠ�ᨨ 犨� ᨨᆠ�泐 ᨨ 맔҈鼀矄҈ᔼ 矄��ᨨ ᨨ 盐 � ᨨ鼀ᆠ�ᆠ � ᨨ ⏌ᆠ鼀ᨨ� � �ᨨ �졔y �ᆠ�ᨨ  鼀� �盐  �ᆠ�ᨨ ᨨ  鼀� �ᆠ � 矄盐�  �矄��ᨨ 矄盐ᆠ   ᆠᨨ ├矄鼀ᨨ� �ᨨ � x �ᆠ�ᨨ 犨�  ᲼㝐� 和 ᔼ㡰桌 㡰 맔҈ ᨨ �졔z �ᆠ�ᨨ

㡰 �맔҈ ᨨ �z �ᆠ�ᨨ

ᆠ㡰 �맔҈ ᨨ �졔z �ᆠ�ᨨ

㡰 맔҈ ᨨ �z �ᆠ�ᨨ

꾀 �ᆠ ᨨ  ᆠ � q   鼀矄矄 m �矄 鼀ᨨ� � 犨�   ᨨᆠ�泐 v $� v ¹ 㡰 ᨨ犨 矄�矄ᆠ ᆠ �  



�

㡰 ҈҈鼀

Ӹ㜠     �矄 ᆠ d ᔼ   �矄  鼀� �ᆠ � ur B = B k$  鼀� �鼀盐鼀盐ᨨ v ᨨ犨 �ᆠ  �ᆠ 犨� ᨨ � 矄ᆠ �矄 ᲼㝐� 和 ᔼ㡰桌 㡰

qdB m

㡰

qdB qdB 㡰 m m 꾀ᆠ � �ᆠᆠ泐� �ᆠ �҈mᔴ�矄鼀ᨨ� �犨� ᨨᆠ�泐 �ˆ +  ˆ + kˆ㡰 鼀矄҈ᔼ    鼀� �ᆠ �



 ᆠ㡰 鼀 㡰 鼀 䰘

ᨨ  ��ˆ +  ˆ - kˆ㡰 ´҈-   �矄矄�  ��ᨨ 犨   �ᆠ �矄 鼀ᨨ� �      ᨨᆠ ᨨ    �ᆠ �矄 ur ur F ´҈-黨  ᆠᨨ F �矄 [㝐� Sep. 03, 2020 (I)] 㡰 - �ˆ +  ˆ - 黨kˆ ᆠ㡰

- �ˆ +  ˆ - 黨kˆ - �ˆ +  ˆ - 黨kˆ



- �ˆ +  ˆ - 黨kˆ

㡰

B

㡰 鼀

qdB m

ᆠ㡰

꾀鼀ᨨ ᨨᨨ 矄犨� 矄 맔҈�鼀矄҈ 矄盐 � ᨨ鼀 鼀� �ᆠ � ᨨ    �ᨨ  ᨨ 鼀� �ᆠ �  �ᆠ ᨨ  矄盐� � �ᆠ ᨨ ᨨᨨ 矄�矄 ᆠᨨ矄ᨨ 㝐矄矄ᨨ  ᨨᨨ 㦨҈䰘맔҈䰘├�ᆠ �ᨨ  ᨨᨨ 㦨҈黨맔҈҈黨ᔴ㡰 [㝐� Sep.02, 2020 (I)] 㡰 ᆠ鼀 㡰 �ᆠ鼀 ᆠ㡰 ҈ᆠ鼀 㡰 ᆠ鼀

 ��盐矄 ᨨ犨矄��ᨨ ᨨ  � �l犨� 盐 � ᨨ鼀 鼀� �ᆠ � ᨨ  � � ᨨᨨ  � � ��ᨨ

犨� ᨨᆠ�泐맔҈�鼀矄҈鼀├� �  � 犨�   � ᔼ  ᨨᨨ ᆠᨨ鼀矄҈ᨨ盐�ᨨ 泐 �鼀� ᆠᨨ矄矄 ��ᨨ 矄 ᨨ犨 �l�矄ᆠᨨ矄ᨨ 鼀矄矄ᨨ ᨨᨨ 㦨 ҈䰘맔҈䰘├�ᆠ �ᨨ  ᨨᨨ 㦨҈맔҈҈黨ᔴ㡰 [㝐� Sep.02, 2020 (II)]



l

꾀�ᆠ � � 矄鼀ᆠ �矄ᨨ ᆠᨨ 鼀ᨨ矄 � ᆠ�ᆠ盐 ᨨ  �盐矄�ᆠ鼀盐  � 盐 ᆠᨨ 鼀� �ᆠ � ᨨ � ᔼ  ᆠ�ᆠ � ᨨ ҈⏌鼀 鼀├矄�ᨨ鼀ᨨ� 矄��     鼀矄矄ᨨ   �ᆠ�矄 ෌� ᆠ �ᨨ ᆠᨨ 㦨҈맔҈҈黨ᔴ㡰 ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 黨҈맔҈҈├� 㡰 ҈맔҈䰘├� ᆠ㡰 ҈맔҈҈黨├� 㡰 맔҈├� 꾀ᨨᨨ  ᆠᨨ  �盐鼀 盐ᆠ盐矄   矄鼀 �泐 泐� ᆠ�ᆠ盐ᨨ�矄�   盐ᨨ 鼀� �ᆠ �  �ᆠ盐ᨨ     �矄ᆠ� ��   ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 >㦨 㡰 㦨 ᆠ㡰  㡰 >>

WWW.JEEBOOKS.IN

P-195

Moving Charges and Magnetism

9.

10.

11.

A proton and an α -particle (with their masses in the ratio of 1 : 4 and charges in the ratio 1 : 2) are accelerated from rest through a potential difference V. If a uniform magnetic field (B) is set up perpendicular to their velocities, the ratio of the radii rp : ra of the circular paths descrfibed by them will be: [Main 12 Jan 2019, I] (a) 1: 2 (b) 1: 2 (c) 1: 3 (d) 1: 3 In an experiment, electrons are accelerated, from rest, by applying a voltage of 500 V. Calculate the radius of the path if a magnetic field 100 mT is then applied. [Charge of the electron = 1.6 × 10–19 C Mass of the electron = 9.1 × 10–31 kg] [Main 11 Jan 2019, I] (a) 7.5 × 10–3 m (b) 7.5 × 10–2 m (c) 7.5 m (d) 7.5 ×10–4 m The region between y = 0 and y = d contains a magnetic r field B = Bzˆ . A particle of mass m and charge q enters the

mv region with a velocity vr = viˆ . if d = , the acceleration 2qB of the charged particle at the point of its emergence at the other side is : [Main 11 Jan 2019, II] qv B æ 1 ˆ 3 ˆö qv B æ 3 ˆ 1 ˆ ö j÷ i + j÷ ç iç (b) m è 2 2 ø m è2 2 ø qvB æ - ˆj + iˆ ö qvB æ iˆ + ˆj ö ç ÷ ç ÷ (c) (d) m è 2 ø m è 2 ø An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii re, rp, ra respectively in a uniform magnetic field B. The relation between re, rp, ra is : [Main 2018] (a) re > rp = ra (b) re < rp = ra (c) re < rp < ra (d) re < ra < rp A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is : [Main Online April 9, 2017] (a) away from the wire (b) towards the wire (c) parallel to the wire along the current (d) parallel to the wire opposite to the current Consider a thin metallic sheet perpendicular to the plane of the paper moving with speed 'v' in a uniform magnetic field B going into the plane of the paper (See figure). If charge densities s1 and s2 are induced on the left and right surfaces, respectively, of the sheet then (ignore fringe [Main Online April 10, 2016] effects):

(a)

12.

13.

14.

15.

- Î0 vB Î vB , s2 = 0 2 2

(a)

s1 =

(b)

s1 =Î0 vB, s 2 = - Î0 vB

(c)

s1 =

Î0 v B - Î0 vB , s2 = 2 2

field occupies a region of space by width ‘d’. If a be the angle of deviation of proton from initial direction of motion (see figure), the value of sin a will be : [Main Online April 10, 2015]

B a d (a)

qV

Bd 2m

B qd 2 mV

(b)

B q q (d) Bd d 2mV 2mV 16. A particle of charge 16 × 10–16 C moving with velocity 10 ms–1 along x-axis enters a region where magnetic field ur of induction B is along the y-axis and an electric field of magnitude 104 Vm–1 is along the negative z-axis. If the charged particle continues moving along x-axis, the ur magnitude of B is : [Main Online April 23, 2013] (a) 16 × 103 Wb m–2 (b) 2 × 103 Wb m–2 3 –2 (c) 1 × 10 Wb m (d) 4 × 103 Wb m–2 ur 17. A magnetic field B = B0 Jˆ , exists in the region a < x < 2a, uv and B = – B0 ˆj , in the region 2a < x < 3a, where B0 is a positive constant. A positive point charge moving with a r velocity v = v0iˆ , where v0 is a positive constant, enters the magnetic field at x = a. The trajectory of the charge in this region can be like [2007]

(c)

B0 0

2a

a

x

3a

- B0 z

(a)

z

a

2a

3a

x

(b)

z

(c)

a

2a

x

3a

z

a

2a

3a

x

a

(d)

2a

3a

x

v

18. An electron travelling with a speed u along the positive x-axis enters into a region of magnetic field where B = –B kˆ B

s1 s2 (d) s1 = s 2 =Î0 vB A proton (mass m) accelerated by a potential difference V flies through a uniform transverse magnetic field B. The

0

(x > 0). It comes out of the region with speed v then [2004S] (a) v = u at y > 0 ×B y

(b) v = u at y < 0 (c) v > u at y > 0

e–

u



(d) v > u at y < 0

WWW.JEEBOOKS.IN

EBD_8341 P-196

҈黨



҈







�

ᨨ  ᨨ矄��泐ᆠ �  �ᆠ鼀ᨨ� ��   x㜠y   � ��泐ᨨ � x㜠 �矄 �矄矄盐  ᆠ  �� �矄   盐ᨨ 矄 ᆠᨨ ᆠ�ᆠ ⏌ᨨ鼀� �ᆠ � 矄 泐ᨨ P ᆠ盐  �矄矄 ᨨ犨 �  x㜠y  �矄 ᨨ盐  ᨨ  ᨨ 㜠ᆠ�ᆠ盐 ␔ �ᆠ  ᨨ  ᨨ    ᨨᨨ犨� � ᆠᨨ鼀� �ᨨ 矄�矄ᨨ矄矄�䁸 ᲼和桌 uur uur y 㡰 E = 錐 B = b�ˆ + ckˆ  uur uur 㡰 E = a�ˆ錐 B = ckˆ + a�ˆ  uur uur ᆠ㡰 E = 錐 B = cˆ + bkˆ uur uur 㡰 E = a�ˆ錐 B = ckˆ + bˆ 꾀�ᆠᨨ 鼀矄矄鼀 ᆠ �q鼀ᨨ矄犨� ᆠᨨ 矄  ᨨᆠ�泐ᨨ � ᨨ矄��x㜠 �ᆠ�ᨨ ᔼ 矄��ᨨ

ᆠᨨ � � �盐 � ᨨ鼀鼀� �ᆠ � B �ᆠ ᨨ � 

�� 㜠 �ᆠ�ᨨ   � � ᨨ鼀x㦨aᨨx㦨b  鼀� �鼀盐鼀盐ᨨ v⼄盐� 矄ᨨ  �ᆠᆠ 盐矄   ��ᨨ x>b�矄 ᲼和桌 qbB q b - a 㡰 B qaB q b + a 㡰 B  ᆠ㡰 㡰  㡰  㡰 m m m m

犨ᨨ�ᆠ矄A  B ᨨ 鼀矄矄矄mA  mB 矄ᆠ�泐   � � 矄鼀ᆠ �鼀ᨨ� ��    꾀 盐 � ᨨ鼀鼀� �ᆠ �  �矄矄 �ᆠ盐ᨨ �矄 

矄 矄ᨨ  �ᆠ矄vA vB矄ᆠ�泐  ᆠᨨ�矄矄矄 ᨨ犨 �   ��盐  ᲼҈和桌 㡰 mAA mBB 꾀 㡰 mAA >mBB  ᆠ㡰 mA mB  A B 㡰 mA 㦨mB  A 㦨B 꾀 �ᨨ �  �矄ᆠᨨ � 矄ᨨ ᨨ矄��  ���ᨨ 矄 ᔼ ��矄矄盐ᆠ 矄�鼀盐 ᨨ盐矄泐ᨨ ᆠ�ᆠ � ᨨ �  졔 㜠 �ᆠ�ᨨ  鼀� �ᆠ � ᨨ � 졔z㜠 �ᆠ�ᨨ  ᲼和桌  

㡰 ᨨ矄�� �ᨨ 矄  ᆠ ᨨ犨 矄 졔y㜠 �ᆠ�ᨨ  

���ᨨ 矄ᨨ犨 矄㜠y �ᆠ�ᨨ

㡰 �ᨨ 矄  ᆠᨨ犨 矄졔y㜠 �ᆠ�ᨨ

ᆠ㡰 �ᨨ 矄  ᆠᨨ犨 矄y㜠 �ᆠ�ᨨ

㡰 ᨨ矄�� �ᨨ 矄  ᆠ ᨨ犨 矄 泐㜠 �ᆠ�ᨨ  

���ᨨ 矄ᨨ犨 矄졔y㜠 �ᆠ�ᨨ  꾀�ᆠᨨ ᆠ �⼄ 鼀矄矄鼀鼀ᨨ矄� ᆠ�ᆠ盐ᨨ� ᨨ  �盐矄犨�  �盐矄  w  �ᨨᨨ  鼀� �盐  ᨨ �矄鼀� �ᆠ鼀ᨨ鼀 ᨨ ᨨ �矄 �盐鼀ᨨ鼀 盐鼀  矄 ᨨ

᲼和桌 㡰 w  q 㡰 w q m ᆠ㡰 q m 㡰 w  m 꾀ᆠ � �ᆠ�矄矄  ᨨ鼀矄� ��ᨨ ᨨ 矄 泐  盐 � ᨨ鼀ᆠ�ᆠ 鼀� �ᆠ � 矄犨 �ᆠ  ᨨᆠ ᨨ  �ᆠ犨�鼀ᨨ� ᲼҈黨黨黨和㜠㝐├矄桌 㡰 矄�� �  㡰 ᆠ�ᆠ ᆠ㡰 � 㡰 ᆠ泐ᆠᨨ� 꾀泐�矄ᆠᨨ

ᆠ 犨 犨ᨨᨨ� 矄A Bᨨ   ᆠ�ᆠ盐鼀  ᆠᨨ 盐 � ᨨ鼀ᆠᨨ 盐ᆠ� �� �ᨨ  �盐矄 矄�矄 ᆠR졠 ᨨ  ᆠ矄ABᨨ  � �矄盐 矄

 �q ᆠ  盐ᨨ  鼀� �ᆠ� 盐ᆠ�ᨨ

 ᆠ  盐ᨨ ᆠ盐 �  � ��矄 ᲼҈黨黨�和桌 㡰 ᨨᨨ�ᨨ ᨨ ҈ q㡰 㡰 � 矄泐ᨨᨨ�ᨨ ᨨ ᆠ㡰 ᨨᨨ 泐� q㦨҈ 㡰 ᨨ ᨨ盐矄ᨨ q

Physics

 犨ᨨ�ᆠ矄X Y � �⼄盐ᆠ �矄 � � ᆠᆠ  ᨨ盐�  矄鼀ᨨ � �  ᆠ  ��ᨨ ᨨ 盐 � ᨨ鼀鼀� �ᆠ �   矄ᆠ�ᆠ�ᆠ盐 矄 ᨨ  ��R҈ R矄ᆠ�泐 �ᨨᨨ  鼀矄矄ᨨ X ᨨ ᨨ Y�矄 ᲼҈黨㜠㝐├矄桌 㡰 R҈ ⏌ R 㡰҈⏌  㡰 R ⏌ R҈ ᆠ㡰 4

R҈ ⏌ R 㡰



R҈ ⏌ R 

Fill in the Blanks

䰘 꾀 盐ᨨ ᨨᨨ   ᆠᨨ    �ᆠ    ��ᨨ  ᨨ  ᆠᨨ 矄  鼀� �ᆠ �  犨�  ⼄盐 ᨨᆠ��矄 鼀� �ᆠ � �矄ᨨ � � 犨  ᨨ鼀 ᨨ  ᨨ   ᆠ├矄ᨨ  �ᆠ矄  �  �� ᆠᨨ  ᨨᨨ犨矄ᆠ├    �ᆠ ᨨᨨ犨矄ᆠ├ ᲼҈黨㜠㝐├矄桌 C

B A

D

5

True / False

 꾀 ᆠᨨ  ᨨᨨ 鼀ᨨ� �犨�  矄鼀├� �ᆠ  �泐ᨨ � 矄鼀 �ᆠ�ᨨ ␔   泐矄矄 ᨨ盐� 盐 � ᨨ鼀鼀� �ᆠ �  �ᆠ盐ᨨ  �ᆠ�ᨨ ᨨ  � 鼀ᨨ�ᨨ   泐 矄ᆠ� ᆠ�ᆠ盐  矄 ᨨ   矄鼀  �盐矄 ᲼҈黨�㜠㝐├矄桌 黨 꾀ᆠ � �ᆠ 矄��ᨨ ᨨ 盐 � ᨨ鼀鼀� �ᆠ �   �ᨨ � ᨨ 鼀� �ᆠ� ᨨ  ᨨᆠ   ᨨ  �ᆠ�矄ᆠ�ᆠ ᲼҈黨㜠㝐├矄桌  �矄 ᨨᆠ  ��   �泐ᨨ ᆠ � �ᆠ 鼀ᨨ� �� 鼀� �ᆠ �  ᨨ盐� 鼀� �ᆠ ᨨᆠ�矄 ᆠ� �ᨨ � ᲼҈黨㜠㝐├矄桌 6

MCQs with One or More than One Correct Answer

҈ 꾀盐 � ᨨ鼀鼀� �ᆠ �  �矄矄�  ��ᨨ 犨

 㦨  㦨 ��ᨨ �   ��盐㡰ᨨ� � � ᨨ鼀泐  � ᨨ  ᨨ  꾀�ᆠ犨� ᆠ �졔턼 鼀ᨨ鼀 盐鼀 �ᆠ ᨨ �  �矄 矄��ᨨ  ᨨ鼀 ��ᨨ ҈  ᨨ�  ҈ 泐 㦨  㡰 ␔ �ᆠ ᨨ    ᨨᨨ犨� � ᨨ�ᨨ 矄㡰�矄⏌ᆠᨨᆠ䁸 ᲼꾀 ҈䰘桌 ��ᨨ ҈ 泐

졠 졔턼



맔 맔 맔 맔 맔 맔

맔 泐㦨 㡰 맔 맔

��ᨨ  맔 맔  맔 맔 맔 맔 맔 맔 맔

��ᨨ  맔 맔 맔 맔 맔 맔 



맔 맔 맔

 ⏌

WWW.JEEBOOKS.IN

P-197

Moving Charges and Magnetism

   �ᆠ犨� ��ᨨ ҈  턼      �ᆠ 犨�   ��ᨨ   㡰 ᨨ  = ҈ 턼  ᨨ盐�  ᨨ� ᨨ   �矄 ᆠ㡰 ␔     �ᆠ  矄 ��ᨨ  ҈  ᨨ盐�    ᨨ �矄ᨨ矄矄� � ��ᨨ  鼀� �盐 ᨨ  ᆠ  �� �矄� 鼀ᨨ鼀 盐鼀犨 ᨨ� ҈     矄ᨨ�  ᨨ鼀泐 �矄�矄⏌  㡰 ᨨ �  �ᆠ矄ᨨ 矄鼀ᆠ �턼 矄鼀 ᨨᆠ�泐  �矄 ᆠ犨  ᨨ� ҈   ᨨ�  ᨨ   泐 � ᨨ ��ᨨ  ҈ �矄 � 矄泐 ᨨᨨ�ᨨ ᨨ 鼀矄矄ᨨ  �ᆠ 꾀 ᆠᨨ 盐ᆠᨨ 矄 ᨨ犨  �    ��盐㡰 ᆠ泐� � ᆠᨨ 矄  ᆠ盐 I�矄├�  x㜠y � 盐 � ᨨ鼀鼀� �ᆠ � r B ᔼ F�矄 鼀� �盐 ᨨ  ᨨ鼀� �ᆠ ᨨᆠᆠ� � ᨨ  ᆠᨨ 盐ᆠᨨ   ᆠᨨᆠ矄鼀  矄㡰�矄 㡰 ᲼꾀 ҈�桌 y R R

㡰 ᨨ  >







p⏌

p⏌

x R R Lr L 㡰 ᔼ  B �矄ᨨ � $z Fµ L졔R㡰 r 㡰 ᔼ  B �矄ᨨ � xˆ F㦨 r ᆠ㡰 ᔼ  B �矄ᨨ � yˆ Fµ L졔R㡰 r 㡰 ᔼ  B �矄ᨨ � $z F㦨 꾀�ᆠᨨ 鼀矄矄M  ᨨ矄��ᆠ �Q, 鼀ᨨ� �犨�  r ᆠᨨ 矄 ᨨᆠ�泐 u҈ = �ˆ 鼀矄-҈  矄��ᨨ ᨨ 盐 � ᨨ鼀 矄�ᆠ鼀� �ᆠ �  ᨨ鼀ᨨ x㜠y  ��ᨨ ᨨ  鼀� �ᆠ �   矄 ᨨ鼀x 㦨ᨨx 㦨L ᨨ盐矄 ᨨ y. 꾀 矄矄� � ᨨ盐�  �矄��ᨨ  �ᆠ鼀�矄 ᨨ   ᨨ  矄�   ҈ 鼀��矄ᆠᨨ 矄 犨�   ᨨᆠ�泐 r u =  �ˆ + ˆ 㡰 鼀矄 -҈  ᆠᨨᆠ矄鼀  矄㡰�矄 㡰 ᲼꾀 ҈桌 㡰  �ᆠ�ᨨ ᨨ  鼀� �ᆠ � �矄 z �ᆠ�ᨨ

㡰  �ᆠ�ᨨ ᨨ  鼀� �ᆠ � �矄졔z �ᆠ�ᨨ

ᆠ㡰 鼀� �盐 ᨨ  鼀� �ᆠ � 

�pM 盐 �矄 Q

҈pM 盐 �矄 Q ᔴᨨ 矄�  鼀ᨨ�ᨨ ᨨ ᨨ矄��ᨨ� ᆠ �� ��ᨨ

犨  矄�鼀盐 ᨨ盐矄盐 � ᨨ鼀ᆠ�ᆠ 鼀� �ᆠ r r � 矄 E = E0 ˆj   B = B0 ˆj . 꾀�鼀t㦨 �矄ᆠ � 矄 r ᨨᆠ�泐 v �  �  x㜠泐 鼀├� �  �q 犨�  x㜠 �矄␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄㡰�矄 㡰ᆠᨨᆠ ᨨ�鼀t>䁸 ᲼҈桌 㡰 ᔼ q = ° ᆠ �鼀ᨨ矄� ᆠ�ᆠ盐 �  x㜠z  㡰 ᔼ q = ° ᆠ �盐 �ᨨ矄 �ᆠ鼀ᨨ�ᨨ 犨� ᆠᨨ 矄 �ᆠ ᨨ � y㜠 �矄 ᆠ㡰 ᔼ q = ҈° ᆠ �盐 �ᨨ矄 �ᆠ鼀ᨨ�ᨨ 犨� �矄�ᆠ � ᆠ矄� �犨� �鼀ᨨ � y㜠 �矄 㡰 ᔼ q = 黨° ᆠ �盐 �ᨨ矄� 盐ᆠᆠ 鼀ᨨ�ᨨ ᨨ � y㜠 �矄

㡰 鼀� �盐 ᨨ  鼀� �ᆠ � �矄



� 꾀 ᆠᨨ  ᨨᨨ 鼀ᨨ� �ᨨ 矄��   矄犨� 矄鼀ᨨᆠ�泐 泐 矄鼀�� � ���ᨨ

ᨨ 盐 � ᨨ鼀鼀� �ᆠ �  �ᆠ盐ᨨ ᨨᆠ�泐 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄⏌盐䁸 ᲼҈҈桌 㡰 泐犨� ᆠᨨ鼀ᨨ盐ᨨ  鼀� �ᆠ � ��ᨨ  㡰 泐犨�ᆠᨨ鼀ᨨ盐� �ᨨ � 矄 ᆠ㡰 泐犨�ᆠᨨ鼀ᨨ盐 矄鼀�鼀 㡰 泐犨�ᆠᨨ鼀ᨨ盐 �  �鼀矄  꾀�ᆠᨨ 鼀矄矄鼀 ᆠ �⼄鼀ᨨ� �犨� ᨨᆠ�泐  矄 ��ᨨ ᔼᔼ ᨨ鼀ᨨ ᨨ盐 泐矄矄 ᨨ犨 �   ��盐 ��ᨨ ᔼᔼ 矄盐 � ᨨ鼀鼀� �ᆠ �  㜠 �ᆠ盐ᨨ  ᨨ    � ᨨ   ��ᨨ

ᔼᔼ�矄 l ᔴ ᨨᨨ矄 ᆠᨨᆠᆠ ᨨ�ᆠ 矄㡰 ᲼桌 ��ᨨ ᔼ ��ᨨ ᔼᔼ ��ᨨ ᔼᔼᔼ 맔 맔맔맔맔맔 맔맔맔맔맔맔 맔맔맔맔맔맔  맔맔맔맔맔맔 맔맔맔맔맔맔 㡰  �ᆠ  矄 ��ᨨ  ᔼᔼᔼ ᨨ 泐� �矄 ᨨᆠ�泐 ⼄l > 鼀 㡰  �ᆠ  矄 ��ᨨ  ᔼᔼᔼ ᨨ 泐� �矄 ᨨᆠ�泐 ⼄l < 鼀 ᆠ㡰   � ᨨ  �ᆠ�  ��ᨨ ᔼᔼ�矄鼀 �鼀盐鼀 ⼄l 鼀 㡰 �鼀矄 �  ��ᨨ ᔼᔼ�矄矄鼀 ᨨ 泐ᨨᆠ�泐矄 ᨨ �矄 �ᆠ盐 矄ᨨ ��ᨨ ᔼ 䰘 졔졔 졠졔졔 � � 矄鼀├� �ᆠ �泐矄矄  ᨨ盐� ��ᨨ � 犨 �ᆠ  �矄盐 � ᨨ鼀鼀� �ᆠ �  �ᆠ盐ᨨ �ᨨᆠ�泐 鼀矄矄矄ᨨ 졔졔 졠졔҈鼀盐鼀盐 ҈鼀盐矄ᆠ�泐 

㡰 졔犨�  ᆠ 鼀ᨨ矄 ᲼҈黨黨㜠㝐├矄桌 㡰 졠졔犨�  ᆠ 鼀ᨨ矄 ᆠ㡰 졔 졠졔犨�  ᆠ ⼄盐泐 㡰 犨�  ᆠ ⼄盐泐  꾀ᨨᨨ 鼀ᨨ� �犨� ᆠᨨ 矄 ᨨᆠ�泐矄矄矄 ᨨ盐� ��ᨨ ᨨ 矄ᆠ犨� ᨨ盐 泐ᆠ  �� �矄ᨨᆠ�泐ᔼ E  B矄  ᆠ�ᆠ 鼀� �ᆠ � 矄矄ᆠ�泐  �矄��ᨨ ᨨ 矄ᆠ鼀泐  ᲼҈黨�㜠㝐├矄桌 㡰 E㦨B㦨 㡰 E㦨B ¹  ᆠ㡰 E ¹ B㦨 㡰 E ¹ B ¹ 

犨  ᨨᆠ�泐  =

8

Comprehension/Passage Based Questions

�ᆠ�ᨨ 矄 턼矄 ҈ ᨨ 㡰  泐ᨨ�泐鼀ᆠ � �   � ᨨ鼀�ᨨ �� �   ᆠᨨ盐鼀 矄ᨨ   ᨨᨨ犨� � 꾀ᆠ � �ᆠ ᆠᨨ ᨨᨨᨨ 㡰�矄� ᨨ 盐ᆠ  ᨨ���

®

㦨泐㦨 㦨㡰犨� �� � ��ᨨᆠ�泐  꾀盐 � ᨨ鼀 ®

®

ᆠ�ᆠ �  쟼  盐 � ᨨ鼀鼀� �ᆠ �    �矄泐犨  ®

®

®

ᨨᆠ�泐  ᆠ�ᆠ �  쟼  鼀� �ᆠ �   ��

� ᆠᨨ盐鼀 矄҈ 矄ᆠ�泐 ⼄盐 ��矄쟼 ᨨ矄��� 鼀� �盐 

WWW.JEEBOOKS.IN

EBD_8341 P-198

Physics

ᔼᔼ㡰

쟼ᆠᨨ 犨� 쟼 ®  =   ˆ  쟼ᆠᨨ 犨� ® 쟼 = 泐ˆ 

�㡰

��㡰

®

ᔼᔼᔼ㡰 ᨨᨨ 犨�   =  ���㡰 ᔼ㡰 ᨨᨨ 犨� 쟼 ®  =   ˆ  黨



҈

�㡰

®

쟼 = 쟼  ˆ

ᔴᨨ盐鼀  㡰

®

쟼 = - 쟼  泐ˆ 턼㡰

®

쟼 = - 쟼  ˆ 㡰

®

쟼 = 쟼  ˆ

和㡰

®

 = -  ˆ

®

 =  ˆ

®

 =  泐ˆ

®

 =  ˆ

ᔼ 犨 �ᆠ ᆠ矄犨� �ᆠ鼀ᨨ� 矄�� � 犨� ᆠᨨ 矄  ᨨᆠ�泐䁸 㡰 ᔼᔼᔼ㡰 ��㡰 㡰 㡰 ᔼ㡰 �㡰 和㡰 ᆠ㡰 ᔼᔼᔼ㡰 ���㡰 㡰 㡰 ᔼᔼ㡰 ���㡰 和㡰 ᔼ 犨 �ᆠ ᆠ矄犨� �ᆠ 矄ᆠ� �ᆠ 犨�  �矄ᨨ � ᨨ矄��  �ᆠ�ᨨ 䁸 꾀㡰 ᔼ㡰 �㡰 和㡰 㡰 ᔼᔼ㡰 ��㡰 㡰 ᔴ㡰 ᔼᔼᔼ㡰 ���㡰 㡰 㡰 ᔼ㡰 ��㡰 㡰 ᔼ 犨 �ᆠ ᆠ矄犨ᨨ盐  �ᆠ鼀ᨨ� 矄�� � ᨨ �   �� �ᆠ�ᨨ ᨨ 泐㜠 �矄 �鼀ᨨᨨ � 泐ˆ 㡰䁸 㡰 ᔼᔼ㡰 ���㡰 턼㡰 㡰 ᔼᔼᔼ㡰 ��㡰 㡰 ᆠ㡰 ᔼ㡰 ��㡰 和㡰 㡰 ᔼᔼᔼ㡰 ��㡰 㡰 10 Subjective Problems





꾀ᨨᨨ     a㜠�ᆠ ᆠᆠ  犨�  矄鼀 ᨨ � �  ᆠ    泐   �   ��ᨨ  ᨨ ᆠᨨ 矄 鼀� �ᆠ � B �ᆠ盐ᨨ ᨨᆠ�泐ᨨ �ᆠ矄 �  �ᨨᨨ  �盐矄ᨨ ᆠ盐盐ᨨ ᨨᨨ ᨨ   �盐矄ᨨ ᆠ盐盐ᨨ a㜠�ᆠ ᲼㜠㝐├矄桌

��ᨨ 犨 x㦨 x㦨L�矄 � 犨� 盐 � ᨨ鼀 矄 泐鼀� �ᆠ �  B kˆ 꾀�ᆠᨨ 鼀矄矄鼀ᨨ矄�� ᆠ �⼄ ᨨᆠ�泐 n�ˆ 矄ᨨ �x㜠 �矄  矄  ��ᨨ ᨨ  鼀� �ᆠ � �ᆠ��泐 ᨨ盐� ᨨ盐  ⼄盐矄�ᨨ  ᲼҈黨黨黨㜠҈㝐├矄桌 㡰 �  盐ᨨ L�  �ᆠ鼀�矄 ᨨ鼀  ��ᨨ ᨨ 鼀� �ᆠ � 犨� �矄 � ᨨᆠ�泐 �  ᨨ�矄� ��ᨨᆠ�泐 㡰 �   � ᨨᆠ�泐ᨨ  �ᆠ  �鼀 矄 泐��  鼀� �ᆠ � �  鼀� �ᆠ �

ᨨ犨  矄盐ᨨ҈L

 꾀 ᆠᨨ �盐 ෌鼀�矄ᆠᨨ 矄 ᨨ  �泐├� ��   ᨨ矄��x㜠 �ᆠ�ᨨ  ᆠᨨ 矄 ⼄盐� ᨨ � 矄ᨨS 犨  GS㦨҈鼀  � ෌和鼀├矄   �ᨨ  犨�   㜠 �矄 矄矄 ᨨ犨 �   ��꾀盐 � ᨨ鼀 

和   ෌



r ® 鼀� �ᆠ �  B ᨨGS �矄矄 �  B ᨨ GS �矄矄�  ��ᨨ ᨨ盐矄�  ᆠᨨ �盐  �   鼀� �鼀盐鼀盐ᨨ B   ᨨ鼀├ ᆠᨨ 矄 �S ᲼҈黨黨㜠䰘㝐├矄桌 � 꾀鼀ᨨ ᨨᨨ 矄犨�  ᨨᆠ�泐맔 ҈�鼀⏌矄ᆠ 矄 盐 � ᨨ鼀鼀� �ᆠ � ᨨ 矄  �ᨨ  ᨨ  鼀� �ᆠ �  �   �盐矄ᨨ   �ᆠ ├ 泐  ᨨᨨ 鼀꾀矄ᨨ �  �ᆠ ᨨ   �  犨 �ᆠ �矄  �矄 ᆠ 泐ᨨᨨ �  鼀ᨨ 鼀� �ᆠ �  盐� �ᨨ �ᨨ ᨨ ᨨ�ᨨ 㡰 ᲼҈黨㜠㝐├矄桌  꾀�ᆠᨨ 鼀矄矄m㦨҈맔҈䰘├� ᆠ �q㦨҈맔҈҈黨ᔴ  矄��ᨨ ᨨ 盐 � ᨨ鼀鼀� �ᆠ � ᨨ 矄 � ҈矄 ᨨ �  �ᆠ�ᨨ 矄 ᨨ犨 �  �� 矄 ᨨ  �ᆠ�矄 ҈䰘鼀⏌矄 �㡰 鼀� �ᆠ � �矄 �ᆠ ᨨ � � 犨

ᨨ鼀ᨨ  ᨨ   �ᆠ矄  ��ᨨ ᨨ   �  ᨨ� F �   �矄 ᆠEF   �q ��㡰ᔼ   �ᆠ�ᨨ ᨨ q   � �矄ᨨ � ᨨ盐犨  ᨨ鼀 ᨨ  ᨨ   �   �鼀 矄  泐   �ᆠ �    쟼 ��ᨨ  ᨨ    鼀� �ᆠ �     � ��E � ҈黨㜠㝐├矄㡰 䰘 꾀ᨨ � �  ᆠᨨ ᨨ矄�矄� ᆠᨨ矄矄  矄ᨨ ᆠᨨ  矄 矄�ᨨ 犨

 矄�矄鼀鼀꾀 ᆠᨨ ᨨᆠ �ᆠ泐 ᨨ  矄 犨�   ᨨᆠ�泐 ᨨ   맔 ҈ 鼀⏌矄ᆠ 鼀ᨨ矄 盐  ᆠ 犨  矄 �  鼀� �盐  �ᆠ�ᨨ ᨨ  鼀� �ᆠ � �  ��ᨨ 犨   ᆠᨨ  矄矄 �ᆠ  � ᆠ矄㡰 ᔴ �ᨨ  ᆠᨨ 㦨҈맔҈҈黨ᆠᨨ盐ᨨ鼀㡰 ᲼҈黨҈㜠㝐├矄桌 졠 和 졔 

ᔼ㡰

ᔴᨨ盐鼀 





ᔴᨨ盐鼀 ҈

Topic-2 : Magnetic Field Lines, Biot-Savart's Law and Ampere's Circuital Law 1 ҈

®

MCQs with One Correct Answer

꾀ᆠ � �ᆠ�ᨨ� �ᨨ盐 � ᆠ�ᆠᆠ ᆠᨨ 矄� 㜠  ᨨᆠ盐 ᨨᨨ꾀�ᆠᨨ 鼀矄矄mᆠ泐� � ᆠ �q�矄鼀ᨨ� ��  犨�矄 v盐  � 盐㜠  ᆠᨨ 鼀� �ᆠ �  ®  鼀� �ᆠ鼀ᨨ鼀 ᨨ  �矄 B 鼀ᨨ� ��ᆠ ᲼㝐� 和 ᔼᔼ㡰桌

㡰

mv  B  B

®

㡰

-

ᆠ㡰

-

B

 pB  ®

®

mv  B

mv  B



-

mv  B  B

WWW.JEEBOOKS.IN

P-199

Moving Charges and Magnetism



꾀犨�A �  矄 ᨨ  ᆠᨨ ᆠ�ᆠᆠ泐� � ᆠ盐 ᨨ 꾀  � � �盐矄ᆠ鼀  ᨨ 犨�B 矄ᨨ �  矄 ᨨ ᆠᨨ ᆠ�ᆠᆠ泐� �ᆠ盐  ᨨ 꾀  � � �盐矄ᨨ ᆠ鼀ᆠ 矄矄 ᨨ犨 �

  ��盐 �ᨨᨨ  鼀� �ᆠ � 矄 盐ᨨ 犨�矄 A B ᆠᨨ鼀鼀ᨨ ᆠ O�矄[Main Sep.04, 2020 (I)] A O



B

黨  㡰  㡰  ᆠ㡰 � 㡰 � 㝐� �盐 ᨨ 鼀� �ᆠ �  � 和ᔼ盐 �矄㡰 ᆠ ᨨ   �ᨨ 矄 ᆠᨨ�ᨨ 矄� ҈ᆠ鼀�盐 矄 ᆠ泐� � m I �矄[Main Sep. 03, 2020 (I)] p 㡰 �  㡰 �  ᆠ㡰 �  㡰 �  꾀泐ᨨ �犨�ABDMNDC�矄矄 ᨨ犨 �  ��盐ᆠ泐� � ᆠ盐 IAB BC矄矄�� ᨨ � ��   �꾀D犨� ᨨ鼀矄ᆠ�ᆠ盐盐 DMNDᨨ  �盐矄R ABBC矄 � �ᨨᆠ�ᆠ盐盐 N D 㝐� �ᆠ �  ᆠ ᨨ ᆠ�ᆠ�矄 ᲼㝐�  ᔼᔼ桌 m I æ ҈ ö p+ 㡰 ÷ pR çè ø m I æ ҈ ö 㡰  pR çè p ÷ ø m I p + ҈㡰 ᆠ㡰 pR m I 㡰 R

犨ᨨ泐ᨨ �矄��  � 矄盐 犨�矄├黨  � ᨨ鼀ᆠ ᨨ � xy㜠 矄矄 ᨨ犨 �   ��盐

ᆠ盐 I 꾀鼀㡰� 盐 �矄ᨨ 



�

矄犨�矄ᆠ泐ᆠ盐 矄ᨨ ⼄盐鼀� �盐 ᔼ犨 ᨨ矄 �ᆠ�ᨨ 矄矄 ᨨ犨 �   ��盐  鼀� �ᆠ � ᨨ� 犨� ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 ᨨ



m I ( xˆ + yˆ )  pd

+m  I m I ( zˆ ) ( xˆ + yˆ ) 㡰 pd  pd �  鼀� �ᆠ � ᨨ�  盐ᨨ矄�� �  矄�鼀 꾀ᨨ  � ᆠ鼀ᆠ泐� �ᆠ盐 ᨨ �꾀 和 ��盐㡰 mᨨ㦨p맔҈䰘㜠꾀㡰 ᲼㝐� ҈꾀�҈黨ᔼᔼ桌

ᆠ㡰 

㡰

䰘

㡰 맔҈�

㡰 ҈�맔҈�

� ᆠ㡰 맔҈

㡰 �맔҈�

꾀矄矄 ᨨ犨 �   ��盐犨ᨨ� � �泐ᨨ ��  �ᆠ犨�矄  泐黨º ᆠ � 矄盐ᆠ 犨泐  矄�鼀 矄  턼㝐ᨨ � x㜠 �矄犨 �矄�鼀 矄和 턼ᨨ y㜠 �矄ᔼ 졠㦨졠턼㦨ᆠ鼀   鼀� �盐 ᨨ  鼀� �ᆠ  � 졠�矄҈   犨ᨨ 犨�矄ᆠ泐⼄盐ᆠ盐 矄 矄 ��盐㡰 鼀� �盐 ᨨ  ᆠ盐 � ᆠ 犨�   �ᆠ�ᨨ ᨨ  鼀� �ᆠ � 졠犨� Ҙ㦨p맔҈䰘꾀㡰 ᲼㝐� ҈ ҈黨ᔼ桌 和

y

졠턼 





x



㡰 꾀 �ᆠ盐ᨨ盐ᨨ  � 㡰 꾀 �ᆠ盐ᨨ盐ᨨ  � ᆠ㡰 꾀 �ᆠ盐� ᨨ � 㡰 꾀 �ᆠ盐� ᨨ �  졠 ᨨ  犨ᨨ�  �ᆠᆠᨨ 盐ᆠ� �犨�矄ᨨ  � �矄  �   ᨨ鼀ᨨ ᆠ�ᆠ盐ᨨᨨ  ᨨ ᨨ � ᨨ ᆠ�ᆠ盐ᆠᨨ�ᨨ �  �ᆠ盐 矄ᔼ  矄鼀ᆠ盐 �矄 矄矄  �  ᨨ    �ᨨ ᨨ    鼀� �ᆠ �     ᆠ ᨨ  ᨨᨨ ҈㡰ᨨ  ᆠ ᨨ  ᆠᨨ�  ᔴ㡰�.e.  犨� ᲼㝐� 黨 ҈黨ᔼᔼ桌 ᔴ ҈ ҈ 㡰  㡰 ᆠ㡰  㡰   黨

 �ᨨ鼀ᨨ鼀 ᨨ ᆠ�ᆠ盐ᨨᨨᆠ泐� �ᆠ盐 ᔼ �矄鼀  鼀� �ᆠ �  ᆠ ᨨ  ᨨᨨ�矄B҈ ␔    �ᨨ鼀ᨨ鼀 �矄 ᨨ盐 泐├� � ᆠ盐  ᆠᨨ 矄  鼀� �ᆠ �  ᆠ ᨨ  ᨨᨨ�矄B B

�ᨨ ҈ �矄 ᲼㝐� ҈桌 B ҈ 㡰  㡰 ᆠ㡰 㡰    ҈ 꾀鼀 ᨨ ᆠᨨ� 矄�ᨨ ᨨᨨ矄ᆠ 犨� N盐 矄  �盐矄R 泐ᆠ ᆠᨨ �泐 �矄 ᆠR    矄鼀 ᆠ盐  I ᨨ犨矄  ᨨ盐�    ᨨᨨ矄 �    矄鼀 �ᆠ�ᨨ  鼀� �盐 ᨨ 鼀� �ᆠ � P鼀� 犨泐 犨  ᆠ 矄A  C�矄�� 泐  ᨨ ��盐㡰 ᲼㝐� 졠 � 꾀�҈�҈桌

WWW.JEEBOOKS.IN

EBD_8341 P-200

Physics

m0 l m0 l 6 [ 3 - 1] 6 [ 3 + 1] (b) 4 pa 4 pa m0 l m0l 3 [ 3 - 1] 3 [2 - 3] (c) (d) 4 pa 4pa An infinitely long hollow conducting cylinder with inner radius R/2 and outer radius R carries a uniform current density along its length. The magnitude of the magnetic r field, B as a function of the radial distance r from the axis is best represented by [2012]

(a)

2R

A

P

C

16.

R

(a)

11.

12.

15.

8 N m0 I 3/ 2

(c)

4 N m0 I 1/ 2

(d)

8 N m0 I

plgL tan q µ0

L q

plgL µ0 cos q plgL (d) 2sin q I I µ0 cos q Consider two thin identical conducting wires covered with very thin insulating material. One of the wires is bent into a loop and produces magnetic field B1, at its centre when a current I passes through it. The ratio B1 : B2 is: [Main Online April 12, 2014] (a) 1 : 1 (b) 1 : 3 (c) 1 : 9 (d) 9 : 1 An electric current is flowing through a circular coil of radius R. The ratio of the magnetic field at the centre of the (c)

14.

3/ 2

(b)

5 R 5 R 5 R 51/ 2 R Two identical wires A and B, each of length 'l', carry the same current I. Wire A is bent into a circle of radius R and wire B is bent to form a square of side 'a'. If BA and BB are the values of magnetic field at the centres of the circle and B square respectively, then the ratio A is: [Main 2016] BB p2 p2 p2 p2 (a) (b) (c) (d) 8 16 8 2 16 2 Two long current carrying thin wires, both with current I, are held by insulating threads of length L and are in equilibrium as shown in the figure, with threads making an angle 'q' with the vertical. If wires have mass l per unit length then the value of I is : (g = gravitational acceleration) [Main 2015] pgL tan q (a) 2 µ0 (b)

13.

4 N m0 I

sin q

coil and that at a distance 2 2R from the centre of the coil and on its axis is : [Main Online April 9, 2013] (a) 2 2 (b) 27 (c) 36 (d) 8 A symmetric star shaped conducting wire loop is carrying a steady state current I as shown in the figure. The distance between the diametrically opposite vertices of the star is 4a. The magnitude of the magnetic field at the center of the loop is [Adv. 2017] I

4a

(a)

r B

(b)

(c)

r B

(d)

r B

r B

17. A loop carrying current I lies in the x-y plane as shown in the figure. The unit vector kˆ is coming out of the plane of the paper. The magnetic moment of the current loop is [2012] 2 ˆ (a) a I k æp ö 2 (b) çè + 1÷ø a I kˆ 2 æp ö 2 (c) - çè + 1÷ø a I kˆ 2 (d) (2p + 1)a2 I kˆ 18. A long insulated copper wire is closely wound as a spiral of ‘N’ turns. The spiral has inner radius ‘a’ and outer radius ‘b’. The spiral lies in the XY plane and a steady current ‘I’ flows through the wire. The Z-component of the magnetic field at the centre of the spiral is [2011] (a)

(b)

(c)

m0 NI æbö ln ç ÷ 2(b - a) èaø

æb+aö m0 NI ln ç ÷ 2(b - a) è b - a ø m0 NI æbö ln ç ÷ 2b èaø

m0 NI æb+aö ln ç ÷ 2b èb-aø 19. A long straight wire along the Z-axis carries a current I in r the negative Z-direction. The magnetic vector field B at a point having coordinates (x, y) in the Z = 0 plane is [2002S] m 0 I xiˆ + yjˆ m 0 I yiˆ - xjˆ (b) (a) 2p x 2 + y 2 2p x 2 + y 2

(d)

(

(c)

(

)

(

m 0 I xjˆ - yiˆ

(

2

2p x + y

2

(

)

)

)

(d)

(

)

)

(

m 0 I xiˆ - yjˆ

(

2

2p x + y

2

)

)

WWW.JEEBOOKS.IN

P-201

Moving Charges and Magnetism



꾀ᆠᨨ� � �N 盐 矄�矄犨ᨨ盐 �� 泐�   ᨨ鼀ᨨ  矄�犨� �

 ᨨ盐 ��a  b 矄ᆠ�泐␔ 

ᆠ盐 I 矄矄矄 ᨨ盐�  ᆠᨨ� 鼀� �ᆠ �   ᆠ �矄 ᲼҈和桌 㡰

mᨨ NI b

㡰

mᨨ NI a

mᨨ NI b mᨨ NI a 



㡰  b  a㡰 a  b  a㡰 b 꾀 ᨨ 㜠 ᨨᨨᨨ ᆠᨨ 盐ᆠ� �犨�ᆠ泐� �ᆠ盐 I �矄 ᆠ 矄矄 ᨨ犨 �   ��盐쟼ᆠ ᨨ  矄�� 矄ᆠ�ᨨ 矄 ᨨ  ᨨᨨ�矄ᨨ  � a 鼀� �ᆠ �  盐ᨨ �矄 ᨨᨨ ᨨ� P aa㡰ᨨ� 矄�   �ᆠ�ᨨ ᲼҈和桌 ᆠ㡰

҈

(

҈  ˆ + kˆ 

㡰

҈  ˆ + kˆ + �ˆ 

ᆠ㡰

҈ ˆ ˆ ˆ � +  +k 

( (

(



)

y ᔼ

)

2

Integer Value Answer

� 꾀ᆠ泐� �ᆠᆠ�泐ᨨ  �鼀 �矄矄� 矄� ᆠ泐� ᨨ �鼀a矄矄 ᨨ犨 �   ��盐ᨨ  ᆠ泐�   ᆠ�泐� � �泐ᨨ �꾀盐 � ᨨ鼀ᆠ盐   矄�泐J ᨨ犨矄ᨨ �  � ᔼ  鼀� �盐 ᨨ  鼀� �ᆠ N �  ᨨ� P�矄�� 泐 m 0 aJ     盐ᨨ ҈ N�矄 ᲼҈桌



)

 ҈ ˆ ˆ � +k  꾀 � � �泐ᨨ �ᆠᨨ 盐ᆠᨨPQR�矄 ᨨ ᨨ鼀��   �矄矄 ᨨ犨 �  ��盐꾀ᆠ盐 I ᨨ犨矄 ᨨ盐� PQR

鼀� �ᆠ �  盐ᨨ �矄ᆠ盐  ᨨ� M�矄H҈ ᨨ犨  ᨨ  � � �泐ᨨ � 矄��  ᆠᨨ 盐ᆠᨨ QS �矄 ᆠᨨ

ᆠ Q矄ᨨ ᆠ盐 �矄I⏌� QR矄犨矄� QS  ᆠ盐 � PQ鼀� � �盐 ᆠ  �  鼀� �ᆠ � M�矄 ᨨ犨H �ᨨH҈⏌H�矄�� 泐 ᲼和桌







)

㡰

 꾀泐�矄ᆠᨨ

ᆠ 犨 犨ᨨᨨ� 矄A Bᨨ   ᆠ�ᆠ盐鼀  ᆠᨨ 盐 � ᨨ鼀ᆠᨨ 盐ᆠ� �� �ᨨ  �盐矄 矄�矄 ᆠR졠 ᨨ  ᆠ矄ABᨨ  � �矄盐 矄

 �q ᆠ  盐ᨨ  鼀� �ᆠ� 盐ᆠ�ᨨ

 ᆠ  盐ᨨ ᆠ盐 �  � ��矄 ᲼҈黨黨�和桌 㡰 ᨨᨨ�ᨨ ᨨ ҈ q㡰 㡰 � 矄泐ᨨᨨ�ᨨ ᨨ ᆠ㡰 ᨨᨨ 泐� q㦨҈ 㡰 ᨨ ᨨ盐矄ᨨ q

¥



m I ᨨᨨ�矄 k æç 0 ö÷  �  盐ᨨ k. è 8 px ø

4



黨

 꾀矄 泐ᆠ盐 I �ᨨ矄 ᨨ盐� 犨�ᨨᨨ턼  � � 矄 ᨨ ��  �� �犨� 턼㦨  㦨  턼 㦨� ᔼ  鼀� �盐 ᨨ  鼀� �ᆠ �  盐ᨨ �矄

Fill in the Blanks

䰘 犨�ᨨᨨPQRSP ᨨ鼀 泐ᨨ� � �犨ᨨ矄鼀�ᆠ�ᆠ盐 犨�矄ᨨ  ��R҈ Rᆠ�矄ᆠ盐 I矄矄 ᨨ犨   鼀� �盐  ᨨ    鼀� �ᆠ � 盐ᆠ�ᨨ     ᆠ  C �矄 ᲼҈黨㜠㝐├矄桌

턼 和

黨

I I





졔¥ 㡰 ҈⏌ 㡰 ҈ ᆠ㡰 ⏌ 㡰 

犨ᨨᨨ �犨�矄 �矄 ᆠd 泐 ᆠ泐矄 泐⼄盐ᆠ盐 矄 ᨨ犨� �ᨨ盐ᨨ   ᨨ   矄矄 ᨨ犨  ��ᨨ ᨨ  鼀� �ᆠ � B ᨨ � �  XXἘ�矄�� 泐 ᲼和桌 B

㡰

B

X

X’ d

㡰

X

d

X’ d

B

ᆠ㡰

X’ d

d B

X

d

᲼黨桌



X

X’ d

d

R S

6

R

 C

R҈ Q P

MCQs with One or More than One Correct Answer

 꾀矄 泐ᆠ盐 ᔼ ᨨ犨矄ᨨ � � � �泐ᨨ � ᨨᨨ犨 ᆠ泐� �ᆠᆠᨨ 盐ᆠᨨᨨ  �盐矄  �矄ᆠ泐� �矄ᆠ ᆠᨨ �泐� 矄�   � � �矄ᨨ ᨨ�  ᨨ  �盐矄   矄ᨨ ᨨ�  矄 盐 矄盐 � �  ᆠ�矄矄 泐 ᆠ盐 ᔼᔴᨨ 矄� ᨨ�  �矄 ᆠ ᨨ鼀 ᆠᨨ鼀鼀ᨨ

 �矄 ᆠᨨᆠ矄鼀  矄㡰�矄 㡰 ᲼꾀 ҈桌 㡰 ᔼ  ��ᨨ   鼀� �ᆠ � �矄 ᨨ 㜠 ᨨ 㡰 ᔼ  ��ᨨ    鼀� �ᆠ � �矄ᨨ �  ᆠᨨ鼀鼀ᨨ  �矄 ᆠ㡰 ᔼ  ��ᨨ    鼀� �ᆠ � �矄 � � ᨨ ᆠ�ᆠᨨ  �盐矄ᆠ  ᨨ   �矄 㡰 ᔼ  ��ᨨ >  鼀� �ᆠ � �矄 ᨨ 㜠 ᨨ

WWW.JEEBOOKS.IN

EBD_8341 P-202

29.

Physics

A current I flows along the length of an infinitely long, straight, thin-walled pipe. Then [1993-2 Marks] (a) the magnetic field at all points inside the pipe is the same, but not zero. (b) the magnetic field at any point inside the pipe is zero (c) the magnetic field is zero only on the axis of the pipe (d) the magnetic field is different at different points inside the pipe.

Y-axis such that OS = OR = 0.02 m. Find the magnitude and direction of the magnetic induction at the origin O. [1989 - 6 Marks] Y

¥

Ii Q Ii

10 Subjective Problems 30.

L

¥

A pair of stationary and infinitely long bent wires are placed in the XY plane as shown in fig. The wires carry currents of i = 10 amperes each as shown. The segments L and M are along the X-axis. The segments P and Q are parallel to the

P

R O

¥

M

S

Ii

X

Ii ¥

Topic-3 : Force and Torque on Current Carrying Conductor 1 1.

3.

MCQs with One Correct Answer

A square loop of side 2a, and carrying current I, is kept in XZ plane with its centre at origin. A long wire carrying the same current I is placed parallel to the z-axis and passing through the point (0, b, 0), (b >> a). The magnitude of the torque on the loop about z-axis is given by : [Main Sep. 05, 2020 (I)] (a)

m0 I 2a2 2 pb

(b)

m 0 I 2 a3

(a) T =

2pb2

2m 0 I 2 a 3 2m 0 I 2 a 2 (d) pb pb 2 A wire carrying current I is bent in the shape ABCDEFA as shown, where rectangle ABCDA and ADEFA are perpendicular to each other. If the sides of the rectangles are of lengths a and b, then the magnitude and direction of magnetic moment of the loop ABCDEFA is : [Main Sep. 02, 2020 (II)]

Z E

I

I

F

C Y

D O X

(a) (b) (c) (d)

A

a

B

æ ˆj kˆ ö abI , along ç + ÷ ç 2 2 ÷ø è æ ˆj kˆ ö 2abI , along çç + ÷ 2 ÷ø è 2 æ ˆj 2kˆ ö 2abI , along ç + ÷ ç 5 5 ÷ø è æ ˆj 2kˆ ö abI , along ç + ÷ ç 5 5 ÷ø è

b

2m IB

(b) T =

pm 2 IB

2pm pm (c) T = IB IB A circular coil of radius R and N turns has negligible resistance. As shown in the schematic figure, its two ends are connected to two wires and it is hanging by those wires with its plane being vertical. The wires are connected to a capacitor with charge Q through a switch. The coil is in a horizontal uniform magnetic field Bo parallel to the plane of the coil. When the switch is closed, the capacitor gets discharged through the coil in a very short time. By the time the capacitor is discharged fully, magnitude of the angular momentum gained by the coil will be (assume that the discharge time is so short that the coil has hardly rotated during this time)

(c) T =

(c)

2.

A small circular loop of conducting wire has radius a and carries current I. It is placed in a uniform magnetic field B perpendicular to its plane such that when rotated slightly about its diameter and released, it starts performing simple harmonic motion of time period T. If the mass of the loop is m then : [Main 9 Jan 2020, II]

4.

Bo

WWW.JEEBOOKS.IN

P-203

Moving Charges and Magnetism

㡰

�

p NQBᨨ R  

㡰 pNQBᨨ R 

ᆠ㡰 pNQBᨨ R  㡰 pNQBᨨ R 

犨ᨨ犨�矄꾀ᆠ泐� �ᆠ盐 矄ᔼ҈ ᔼ矄矄 ᨨ犨

�   ��盐 矄�ᨨ 犨  鼀�矄 꾀 � 犨�ᔴᆠ泐� �ᆠ盐 ᔼ�矄ᨨ├ᨨ 鼀  �矄 ᆠ  ᨨ鼀꾀矄盐ᆠ     ᨨᆠᆠ� �ᨨ ��矄 ᨨ ᨨ矄矄�盐矄ᨨ  ᲼㝐� ҈꾀�҈黨ᔼ桌

ᆠ�矄ᆠ盐 ҈ᨨ ҈꾀졠盐ᨨ   ᨨᨨ犨� � �   ᨨ� �ᨨ 矄犨 �ᆠ ᨨ ᆠᨨ矄ᨨ 矄ᨨ矄⼄盐���盐鼀䁸 ᲼㝐� 졠 � 꾀�黨҈䰘桌 

 

ᆠ  ᔼ ᔼ  

㡰

Ӹ

ᔼ 

ᆠ ᔼ

㡰







 



ᆠ㡰



ᔼ ᔼ ᆠ



Ӹ







æ ᔼ ö ᔼ = ç ҈ ÷   = ᔼ҈ + ᔼ 㡰 è ᔼ҈ - ᔼ ø

㡰

æ ᔼ ö æ ᔼ ö =ç   = ç ÷ è ᔼ҈ + ᔼ 㡰 ø è ᔼ҈ - ᔼ 㡰 ÷ø

æ ᔼ҈ ö æ ᔼ ö ᆠ㡰 = çè ᔼ + ᔼ 㡰 ÷ø   = çè ᔼ - ᔼ 㡰 ÷ø ҈  ҈  ᔼ҈ 㡰 = ± ᔼ - ᔼ 㡰 ҈  꾀��� 矄⼄盐ᨨ ᨨᨨᨨ 矄� � ᆠ泐� �ᆠ盐 ᔼ�矄 泐� �ᨨ  ᨨ� ᨨ 矄盐 ᆠ ᨨ �ᆠ盐 ᔼ҈ᆠ泐� � 犨��  矄鼀 矄矄 ᨨ犨 �  ��盐   ᨨᆠ ᨨ  ᨨᨨ 盐ᨨ 犨�犨�᲼㝐� 黨꾀�҈黨ᔼ桌

ᔼ

ᔼ҈

z



黨



y ᔼ

x

z 

㡰







y



x

z 



ᔴ㡰









x

z 

㡰 







Br  I Bpr  I 㡰 ᨨ 㡰 Bpr2I N ᆠ㡰 N pN 꾀ᆠ �⼄�矄矄 盐 � ᨨ鼀泐ᨨ � 矄盐 ᨨᨨᨨ  �盐矄ᔼ ��矄ᨨ 犨�   �盐ᨨᆠ�泐w犨� 矄ᆠᨨ ᨨ鼀 �矄   鼀� �ᆠ鼀ᨨ鼀 ᨨ   ᨨᨨ�矄 ᲼㝐� 졠 � 꾀�҈҈桌 ҈   ⼄w  㡰 ⼄w  ᆠ㡰 ⼄w  㡰 ⼄w  㡰    꾀盐 � ᨨ鼀鼀� �ᆠ � ᨨ  �矄ᨨ � ᨨ矄��㜠 �ᆠ�ᨨ 꾀ᆠ �盐ᨨᨨ ᆠ 㡰ᨨ 矄� 矄҈ᆠ鼀맔�ᆠ鼀

Ӹ

҈҈ 꾀ᆠ �盐ᨨᨨᨨ 矄� 矄҈ᆠ鼀 �ᆠ鼀ᆠ泐� � ᆠ盐 ҈ᨨ ҈꾀�矄ᆠ �  �  ᨨ� �ᨨ 矄矄矄 ᨨ犨

�   ��盐矄ᨨ犨



䰘

ᔼ ᔼ ᆠ

҈ 犨ᨨᆠᨨ �矄ᨨ ᨨ� 矄ᨨ  �   �盐矄ᆠ泐ᆠ盐 ᔼ�

uur  矄鼀 �ᆠ�ᨨ  ҈  鼀� �ᆠ ᨨᆠᨨ  �

 uur 矄ᨨ ᨨ�  盐ᨨ ᨨ盐ᨨ     鼀� �ᆠ ᨨᆠ ᨨ  ᨨ盐矄ᨨ ᨨ�  盐ᨨ �

ᨨ    uur uur 㡰 ҈ �矄 �泐� 犨 矄   㦨 ᲼㝐� ҈�桌 uur uur 㡰 ҈ �矄 �泐ᨨ盐犨 矄   㦨 uur uur ᆠ㡰 ҈ 㦨  㦨 uur uur 㡰 ҈ �矄 �泐� 犨 矄   �矄 �泐ᨨ盐犨 矄

꾀㡰

m II 㡰 盐矄� ⼄盐ᨨ ᨨ ҈  p mᨨ I҈I  㡰 꾀ᆠ� ⼄盐ᨨ p mᨨ I҈I  ᆠ㡰 盐矄� ⼄盐ᨨ p 㡰 ᨨ 꾀ᆠ�ᆠ盐ᆠᨨ� � �盐 矄  �盐矄rᆠ�矄ᆠ盐 I ᔼ�矄  �   � 鼀� �ᆠ �  ᨨ⼄盐ᨨ

 ᆠᨨ� 盐ᨨ 鼀� �ᆠ � �矄᲼㝐� 꾀�҈黨ᔼ桌







㡰

Ӹ



㡰





x





y

ᔼ  �矄盐 � ᨨ鼀鼀� �ᆠ � ᨨ  �  ᨨ矄�� �ᆠ�ᨨ � 犨 �ᆠ ᨨ� �ᨨ 矄 ᨨᨨ犨ᨨ盐 �  �㡰 矄⼄盐���盐鼀  ��㡰盐 矄⼄盐���盐鼀䁸᲼㝐� ҈�桌 㡰 㡰  㡰矄ᆠ�泐 㡰 㡰  ᔴ㡰矄ᆠ�泐 ᆠ㡰 꾀㡰  㡰矄ᆠ�泐 㡰 꾀㡰  ᔴ㡰矄ᆠ�泐

WWW.JEEBOOKS.IN

EBD_8341 P-204

҈

Physics

犨ᨨ ᨨ � 矄��   犨�矄 ᆠ泐� �  盐矄㡰 ᆠ盐 ᔼ҈ ᔼ├ �矄 ᆠ ᔼ   ᨨᆠ � 犨  犨ᨨ犨�矄�矄├ 矄�ᨨ矄��犨    犨�矄ᆠ ᨨ  � ��犨   犨�矄ᆠ ᆠ  ᨨ    �  矄 ᨨ犨� �    ᆠᨨ �  ᨨ

 ᨨ 盐ᆠᔼ҈ᔼ犨ᨨ盐 ᲼㝐� 졠 � 꾀�҈҈҈�桌



ᔼ҈ᔼ

㡰 㡰 ᆠ㡰 㡰





҈

I

㡰

ᔼ҈ᔼ





ᆠ㡰

i





㡰

҈ 꾀ᆠ �盐ᨨᨨᆠ泐� �ᆠ盐 ��矄矄�盐   ᨨ �矄�� 犨�矄盐ᆠ   犨��矄ᨨᨨ ᨨ  矄� 矄ᨨ  ᨨᨨ �矄�   ᨨ  ᨨᨨᔼ 矄 泐ᆠ盐 I�矄矄�矄  �  犨�矄矄 ᨨ犨 �   ��盐 ᨨᨨ犨� ᲼҈黨�㜠㝐├矄桌



ᔼ҈ᔼ

2

ᔼ҈ᔼ



矄�� ᆠ盐 ᆠ泐� �ᆠᨨ 盐ᆠᨨ矄 矄 ᨨ犨 �   ��盐  ᨨᆠ � ᆠ 泐 鼀�  ᆠᨨ 盐ᆠᨨᨨ  � �ᆠ鼀�矄᲼㝐� 졠 � 꾀�҈҈҈桌 ᔼ҈ 㦨꾀

ᔼ 㦨꾀

ᨨᨨ盐  �矄ᨨ 犨� 鼀ᨨ犨泐 ᨨ鼀 犨� 鼀ᨨᨨ犨 矄 犨� 鼀� 矄�ᨨ 泐 Integer Value Answer

҈䰘 犨ᨨ犨�矄�   ᨨ   �矄 ᆠX Aᨨ� ᆠ ��矄鼀ᨨ� �犨� 矄 u犨   犨�矄�  矄鼀  �矄 ᆠX҈ ᨨ鼀ᨨ ᨨ   犨�矄␔   犨�矄ᆠ泐ᆠ盐 ᨨ 鼀� �盐 I �   矄鼀 �ᆠ�ᨨ   �盐矄ᨨ ᆠ盐盐ᨨ   ᨨ   ᨨ� ᆠ ��矄R҈ᔼ ᆠᨨ 矄�  ᆠ盐 矄I �  犨ᨨ 犨�矄  �ᆠ�ᨨ 矄ᨨᨨ矄�ᨨᆠ ᨨ   �盐矄ᨨ R X ᆠ盐盐ᨨ   �矄Rᔼ   =   盐ᨨ  ҈ �矄 R X҈ ᲼꾀 ҈桌

�ᆠ鼀

ᆠ鼀

4

ᔼ㦨҈꾀

맔҈ᨨ犨 �� 

㡰 㡰 맔҈ᨨ犨 ��  ᆠ㡰 黨맔҈ᨨ犨 ��  㡰 ᨨ ҈

҈ 꾀犨�ABCDEF 犨� ᆠ 矄� ᨨ  � L㡰 矄矄 ᨨ犨

�  ��盐 ᆠ泐� �ᆠ盐 I�矄ᆠ � 盐 � ᨨ鼀 鼀� �ᆠ� 盐ᆠ�ᨨ Bᨨ ᨨ矄��y㜠 �ᆠ�ᨨ 

 ᨨᆠ � ᆠ 泐 犨��矄�   �ᆠ�ᨨ  ᲼҈黨黨㜠㝐├矄桌 z D

꾀ᆠᨨ 盐ᆠ� �ᨨᨨᆠ泐� �ᆠ盐 I�矄ᆠ � 盐 � ᨨ鼀 鼀� �ᆠ �  ᨨ� � � � ᨨ     ᨨ    矄 矄 ᨨ犨  ᨨᨨ犨�   ᆠ泐ᨨ ᲼和桌

C

F E

㡰  



y



ᆠ㡰 鼀ᨨᨨ犨 矄졔x㜠 �矄

B

㡰 鼀ᨨᨨ犨 矄㜠x㜠 �矄

犨ᨨ � ᨨ �犨�矄矄 泐 �矄 ᆠ�b ᆠ泐� �ᆠ盐 ��鼀ᆠ  鼀� �盐 ᨨ   ᨨᆠ 盐 � �   泐ᨨ 犨�ᨨ  ᨨ �矄 ᲼҈黨㜠㝐├矄桌 㡰

m � 



I

Ӹ



㡰 ᆠᨨ ᆠ

҈�

Fill in the Blanks



㡰

m �  p

ᆠ㡰

m � p



m � p 

A

x

5

True / False

҈黨 ᨨ  ᨨᆠᆠ矄ᨨ ᆠ �盐ᆠᨨ�ᆠ泐� �矄 泐 ᆠ盐 犨  矄盐矄   泐� 盐 � ᨨ鼀鼀� �ᆠ �  ᲼҈黨҈㜠㝐├矄桌

WWW.JEEBOOKS.IN

P-205

Moving Charges and Magnetism Ӹ

10 Subjective Problems

҈

� � �泐ᨨ � � 犨�矄ᆠ ᆠ泐� �ᆠ盐 ��

 矄鼀 �ᆠ�ᨨ �  x㜠y ᨨ ��泐  矄ᆠ ᆠ 犨��矄ᨨ � y㜠 �矄犨 � ᨨ  犨ᨨᨨ �x㦨᠀d ᲼҈黨黨䰘㜠�㝐├矄桌 �㡰 �  ᨨᆠ盐矄ᨨ  ᨨ� 矄 ᨨ犨 �ᆠ  鼀� �ᆠ � B�矄 ᨨ ��㡰 ᔼ  ᆠ 犨��矄 �矄ᆠ ᨨ �  Z㜠 �ᆠ�ᨨ

泐矄鼀鼀ᨨ盐   矄 矄 ᨨ犨 �犨�  ᆠ盐矄�鼀 鼀ᨨ �ᆠ鼀ᨨ�ᨨ ᔼ  �   矄�泐 ᨨ  犨�矄�矄l �   ⼄盐 ᆠ泐ᨨ ᨨ矄ᆠ��ᨨ  꾀ᨨ � ᨨ� ᨨ 犨�AB犨 �ᆠ �矄 ᨨ鼀ᨨ� �ᆠ   ᆠ�矄矄 泐ᆠ盐 ᨨ A�矄� ⼄盐���盐鼀  �� ᨨ ҈鼀ᨨ ᨨ ᨨ �犨�CD 犨 �ᆠ �矄 �  �  ᨨ� ᨨ   ᆠ�矄矄 泐 ᆠ盐 ᨨ A矄矄 ᨨ犨 �  ��盐和 ᨨ犨 犨  AB�矄 矄�� 泐 矄矄 � ᆠ盐矄矄�鼀 鼀ᨨ �ᆠ鼀ᨨ�ᨨ  �  �ᨨ ᨨ ᨨ矄ᆠ��ᨨ 矄 ᲼҈黨黨㜠㝐├矄桌











ᔼ  犨�矄A Bᆠ ᆠ泐ᆠ盐 I鼀� ᨨ   ᨨ  ᨨ�   矄矄�ᨨ  ᨨ  ᨨᆠᆠ� � ᨨ  矄�鼀 OC␔ 犨�  ᨨᆠᨨ OC�   ᆠ盐 �  犨�B�矄矄 䁸 ᲼҈黨黨㜠҈㝐├矄桌  犨ᨨ ᨨ � 矄��   犨�矄   鼀矄   �ᆠ盐ᨨ  ᨨ   矄 ��盐㡰  犨�Aᆠ�矄ᆠ盐 ᨨ 黨鼀矄 �ᆠ � ᨨ   ᨨ   犨�Bᆠ�矄ᆠ盐 矄盐ᆠ    鼀� �ᆠ � ᨨ � 盐ᆠ�ᨨ  ᨨ�  P �矄 ᆠᨨ



 ᔴ 꾀矄�� 矄�鼀 OC ᨨ  � L鼀㡰ᨨ ᆠ�ᆠ盐� ᆠ泐� �ᆠ盐 I鼀�矄ᆠ ᨨ �  㜠 �矄 ��㡰

犨ᨨ� � 泐ᨨ �矄�� 犨�矄A Bᆠ   � � ᨨ鼀z 㦨 - ¥ ᨨ +¥  �  y㦨a鼀 y㦨졔a 鼀矄ᆠ�泐矄矄 ᨨ犨 �   ��盐

᲼҈黨䰘㜠䰘㝐├矄桌 A×



҈ 鼀 ᨨ鼀 犨�B�矄 ᨨ ҈҈ �  �㡰 鼀� �盐   �ᆠ�ᨨ

ᨨ  ᆠ盐 � B ��㡰 鼀� �盐 ᨨ  鼀� �ᆠ � ᨨ � 盐ᆠ�ᨨ  ᨨ� S ���㡰  ᨨᆠ盐 � � ᨨ   犨�B

҈







鼀





和 鼀 ҈

B

҈⏌ 鼀 ҈҈ 

Topic-4 : Galvanometer and its Conversion into Ammeter and Voltmeter 1 ҈





MCQs with One Correct Answer

꾀� ᨨ鼀ᨨ 矄�矄 ᆠ෌�矄ᆠᨨ  � ᨨᨨ㜠 鼀ᨨ � ҈泐ᆠᨨ

ᆠ� �矄�矄 ᆠ ҈�

矄�矄犨� �  ��ᨨ 矄�矄 ᆠ ҈� 矄�矄犨� �

 ��ᨨ 矄�矄 ᆠ 矄 ᨨ盐 ᆠᨨ

ᆠ � 矄㜠 �矄犨�  ҈ᨨ� ᆠ矄  �ᨨ  ᨨ鼀ᨨ 犨� ᲼㝐� 和� ᔼ㡰桌 㡰 ෌ 㡰 ҈ ᆠ㡰 ҈෌ 㡰 ҈졔෌ 꾀� ᨨ鼀�矄盐矄 � ᨨᨨ泐 ᨨ ᆠ� �  盐 ᨨ� � ᆠ�ᆠ �鼀 矄ᔼ ᨨ 矄矄� �ᆠ盐 ᨨ  鼀꾀�ᨨ 盐ᆠ矄  ᆠ�ᨨ ᨨ  �矄 ��盐ᨨ 鼀��矄ᆠᨨ矄 ᨨ ᲼㝐� 和� ᔼᔼ㡰桌 㡰  꾀⏌ � 㡰 맔҈꾀⏌ � ᆠ㡰  꾀⏌ � 㡰 맔҈꾀⏌ � 꾀鼀ᨨ� �ᆠᨨ�� ᨨ鼀ᨨ犨矄 盐矄ᆠᆠ盐 ᨨ 10꾀꾀矄�矄矄�矄 ᆠᨨ 㝐W �矄⼄盐� ᨨᆠᨨ   ᨨ� ᨨ鼀� ᨨᨨ鼀ᨨ  ��

 ᨨ   盐 ᨨ  矄 盐  矄�矄 ᆠ ⼄盐�  ᨨ ᆠᨨ  ᨨ� ᨨ鼀� ᨨ 鼀鼀ᨨ  � ҈鼀꾀�矄 ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 �W 㡰 ҈W ᆠ㡰 W 㡰 ҈W



�



꾀鼀ᨨ� �ᆠᨨ�� ᨨ鼀 矄矄�矄 ᆠ�W � � �ᆠ矄 盐  ᆠ�ᨨ 鼀꾀ᆠ盐 꾀ᨨ鼀�矄 鼀 盐矄� � �矄� ᨨ鼀 �├W矄�矄 ᆠ  鼀 �鼀盐鼀 ᨨ�   ᆠ   鼀矄盐  盐矄� �  �矄 ᨨ鼀犨�ᆠᨨ矄ᨨ ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰  㡰 ҈� ᆠ㡰  㡰 ҈ 꾀鼀ᨨ� �ᆠᨨ�� ᨨ鼀 矄ᆠᨨ�犨� ҈䰘�盐 矄 ҈ᆠ鼀ᔼ盐矄矄ᨨ矄�ᨨ  ᨨ ᨨ矄�ᨨ ᆠᨨ 矄 ҈㜠鼀⏌   ᆠᨨ��矄ᆠ � 鼀� �ᆠ � ᨨ�矄 

ᆠᨨ�  ᆠ矄泐҈  ᨨᆠ盐 ᨨ ҈鼀꾀 盐ᨨ  �

矄㡰�矄ᨨ �鼀泐 ᲼㝐� 黨꾀�҈黨ᔼᔼ桌 㡰 ҈ 㡰 ҈ ᆠ㡰 ҈҈ ᆠ㡰 ҈

� ᨨ鼀  ᆠ�ᨨ 犨  ├泐⧤҈�矄ᆠᨨ矄 盐 ⧤�矄ᨨ ⼄盐矄 θ  矄 ��盐㡰졠 ᆠᨨ矄� �⧤矄ᨨ   盐矄� � ᨨ�W   ᆠ�ᨨ � � ᨨ鼀 θ ᆠᨨ鼀矄   矄�矄 ᆠᨨ  � ᨨ鼀�矄   � �� 泐᲼�ᆠ �  矄�矄 ᆠᨨ 泐桌 ᲼㝐� ҈ ҈黨ᔼ桌

WWW.JEEBOOKS.IN

EBD_8341 P-206

Physics R2

K2 R1 = 220 W

G

K1

7.

8.

9.

10.

11.

12.

13.

(a) 5W (b) 22W (c) 25W (d) 12W A galvanometer, whose resistance is 50 ohm, has 25 divisions in it. When a current of 4 × 10–4 A passes through it, its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range 2.5 V, it should be connected to a resistance of : [Main 12 Jan 2019, II] (a) 250 ohm (b) 200 ohm (c) 6200 ohm(d) 6250 ohm A galvanometer having a resistance of 20 W and 30 division on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is: [Main 11 Jan 2019, II] (d) 125 W (a) 100 W (b) 120 W (c) 80 W A galvanometer having a coil resistance 100 W gives a full scale deflection when a current of 1 mA is passed through it. What is the value of the resistance which can convert this galvanometer into a voltmeter giving full scale deflection for a potential difference of 10 V? [Main 8 Jan 2019, II] (a) 10 kW (b) 8.9 kW (c) 7.9 kW (d) 9.9 kW In a circuit for finding the resistance of a galvanometer by half deflection method, a 6 V battery and a high resistance of 11kW are used. The figure of merit of the galvanometer 60mA/division. In the absence of shunt resistance, the galvanometer produces a deflection of q = 9 divisions when current flows in the circuit. The value of the shunt resistance that can cause the deflection of q/2 , is closest to [Main Online April 16, 2018] (a) 55W (b) 110W (c) 220W (d) 550W When a current of 5 mA is passed through a galvanometer having a coil of resistance 15 W , it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into to voltmeter of range 0 - 10 V is [Main 2017] 3 (a) 2.535 ´ 10 W (b) 4.005 ´ 103 W (c) 1.985 ´ 103 W (d) 2.045 ´ 103 W A galvanometer having a coil resistance of 100 W gives a full scale deflection, when a currect of 1 mA is passed through it. The value of the resistance, which can convert this galvanometer into ammeter giving a full scale deflection for a current of 10 A, is : [Main 2016] (a) 0.1 W (b) 3W (c) 0.01W (d) 2W To know the resistance G of a galvanometer by half deflection method, a battery of emf VE and resistance R is used to deflect the galvanometer by angle q. If a shunt of resistance S is needed to get half deflection then G, R and S related by the equation: [Main Online April 9, 2016] (a) S (R + G) = RG (b) 2S (R + G) = RG (c) 2G = S (d) 2S = G

3

Numeric Answer

14. A moving coil galvanometer has 50 turns and each turn has an area 2 ×10–4 m2. The magnetic field produced by the magnet inside the galvanometer is 0.02 T. The torsional constant of the suspension wire is 10–4 N m rad–1. When a current flows through the galvanometer, a full scale deflection occurs if the coil rotates by 0.2 rad. The resistance of the coil of the galvanometer is 50 W. This galvanometer is to be converted into an ammeter capable of measuring current in the range 0 –1.0 A. For this purpose, a shunt resistance is to be added in parallel to the galvanometer. The value of this shunt resistance, in ohms, is __________. [Adv. 2018] 6

MCQs with One or More than One Correct Answer

15. Two identical moving coil galvanometers have 10 resistance and full scale deflection at 2mA current. One of them is converted into a voltmeter of 100mV full scale reading and the other into an Ammeter of 1mA full scale current using appropriate resistors. There are then used to measure the voltage and current in the Ohm’s law experiment with R – 1000W resistor by using an ideal cell. Which of the [Adv. 2019] following statement(s) is/are correct? (a) The resistance of the voltmeter will be 100k (b) The measured value of R will be 978 矄盐 � ᨨ鼀鼀� �ᆠ �  B҈kˆ   ��ᨨ y 矄 ᨨ 盐 � ᨨ鼀鼀� �ᆠ �  B kˆ 꾀ᨨ矄��泐ᆠ � �ᆠ�矄ᨨᆠ  ᨨ鼀  ᨨ��� ᨨ � ᨨ矄��y㜠 �矄犨� 矄 v㦨p 鼀矄 ҈t㦨矄矄 ᨨ犨 �   ��盐�ᆠ��泐�  �矄

�

꾀ᨨ �ᆠ�ᆠ盐盐ᨨ  � ҈鼀  �盐矄鼀ᆠ�矄 ᆠ盐 Iᨨ ��矄ᆠ盐 矄盐 ᆠ矄矄 ᨨ犨 꾀犨�㜠ᨨᨨᨨ 矄�矄 ᆠ�ᨨ 鼀 ᨨ  �盐矄҈鼀�矄 ᆠ  � 矄�    盐 犨�  �矄  �矄 ᆠᨨ� ᆠ� � �犨�   �矄ᨨ  盐  ᆠ盐 �矄矄 I㦨Iᆠᨨ矄 t㡰犨  I�矄 ᆠᨨ 矄  ᔼ   鼀� �ᆠ鼀ᨨ鼀  ᨨ   ᨨᨨ�矄NmI矄�  t㡰  �N�矄 ᲼҈҈桌 4



Fill in the Blanks

꾀鼀�ᆠᨨᆠ├ᆠ泐� �ᆠ盐 ᔼ�矄矄盐ᆠ ᨨ盐 � ᨨ鼀 ur 鼀� �ᆠ� 盐ᆠ�ᨨ  B 矄矄 ᨨ犨 �  ��盐 B

Y

E

G F

H B

X I

A C

D Z

ur

鼀ᨨ� �ᆠ �矄 � ᆠ ᨨᆠ F �� 泐 犨 �ᆠ 矄盐矄�  ᨨ犨� �ᨨ  ᨨ �ᨨ   ᆠ 꾀矄矄盐鼀 矄 ᨨ  ᆠ�矄ᨨv ᲼҈黨黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-208

Physics

6 䰘



MCQs with One or More than One Correct Answer

犨ᨨ� � �泐ᨨ �矄�� 犨�矄��  xy㜠 ᨨ �  � 矄x㦨 ᠀R 犨�ᨨᆠ  x㦨 졔Rᆠ�矄 ᆠᨨ 矄 ᆠ盐 I҈  犨�ᨨᆠ x㦨Rᆠ�矄 ᆠᨨ 矄  ᆠ盐  I  꾀 ᆠ�ᆠ盐 ᨨᨨ ᨨ   �盐矄 R �矄 矄盐矄  犨� �矄ᆠ   R 㡰 �   ᨨ xy㜠  �矄ᨨᨨᆠ�矄ᆠᨨ 矄 ᆠ盐  I�  ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ 矄矄  ᨨ鼀ᨨ ᨨᨨ

ᆠ盐 �  犨��矄├ ᨨᨨ矄��� ��矄�   + ˆ  �ᆠ�ᨨ ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄� � � r  鼀� �ᆠ �  Br �矄 㡰盐䁸 ᲼꾀 ҈桌 㡰 ᔼ I҈㦨I   B ᆠ

ᨨ⼄盐ᨨ ᨨ ᨨ���

㡰 r 㡰 ᔼ I҈> I   B ᆠ ⼄盐ᨨ ᨨ  ᨨ���  㡰 r ᆠ㡰 ᔼ I҈ I>   B ᆠ ⼄盐ᨨ ᨨ  ᨨ���  㡰 㡰 ᔼ I҈㦨I   z㜠ᆠᨨ鼀ᨨ  ᨨ  鼀� �ᆠ � æ m I ö  ᆠ ᨨ  ᨨᨨ�矄 ç  ÷ è R ø

犨ᨨ鼀�ᆠ� �矄A B�  �ᆠ� 矄  矄� 盐 � � �  矄�矄���矄rA  rB├ᨨ ᨨᨨ 犨ᨨ�  �ᆠ 矄ᨨ ᨨ� 矄 矄 矄 ᨨ犨  �    ��盐 ␔ 

ᆠ盐 I�矄矄犨�ᆠ  ᨨ � ᨨ  矄ᨨ ᨨ� 矄� �  �ᆠ 鼀

  � �矄 A   B 盐鼀 ᨨ �� 矄 hA   hB 矄ᆠ�泐犨� hA>hB ᨨ矄矄��ᨨ 矄㡰犨

 �矄�矄���矄  �鼀矄矄矄mA mB�矄 㡰 ᲼黨桌 A

㡰 rA>rB  mA㦨mB ᆠ㡰 rA>rB mA>mB 黨

B

㡰 rArB mA㦨mB 㡰 rArB mAmB

7 Match the Following

犨ᨨ犨�矄ᆠ ᆠ泐� �矄 泐ᆠ盐 ᔼ矄 ᨨ犨 �

ᨨ盐ᆠᨨ ��盐�ᨨ 矄� ᔴᨨ盐鼀 ᔼ和ᨨ鼀ᨨ  矄盐� �  ᆠ矄 矄ᆠ� � ᔴᨨ盐鼀 ᔼᔼ㝐ᆠ  矄鼀 矄 � ᔴᨨ盐鼀 ᔼ犨�  矄鼀 矄� ᆠᨨ盐鼀 ᔼᔼ � �ᆠ 泐ᨨ盐  矄犨 泐 ├ � � ᨨ�  盐矄 �    맔鼀� �� �  졠 和 ᲼䰘桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰 ᨨ� �矄矄�盐 㡰 鼀� �ᆠ � 矄 㡰 鼀� 犨泐犨    盐ᨨ ᆠ盐 矄 犨�矄 �  犨�矄�   矄鼀 �ᆠ�ᨨ  

㡰 ᨨ� �矄矄�盐 ⼄㡰 鼀� �ᆠ � 矄 㡰  鼀� 㜠ᨨ� ᨨ    盐ᨨ ᆠ盐 矄 � ᨨ� � � ᆠ 矄 �  犨�矄� ᨨᨨ ᨨ  ᆠ�ᆠ盐 犨�矄 矄� �ᆠ�ᨨ 矄 犨 �ᆠ  矄鼀 �� 

ᔴ㡰 ᨨ� �矄矄�盐  㡰  鼀� 㜠ᨨ� ᨨ   � ᨨ� � � ᆠ 矄 ᨨ  ᆠ�ᆠ盐犨�矄 犨 �ᆠ  矄鼀 ��

�矄 ᨨ鼀� �ᆠ � 



㡰 ᨨ� �矄矄�盐   ᆠᨨ鼀鼀ᨨ ᆠ  ᨨ  犨�矄

矄㡰 犨�矄ᆠ ᨨ 



҈ ᔴᨨ盐鼀  ᔼ ��矄 ᆠ�  矄�盐�ᨨ 矄 �  犨 �ᆠ   矄��  鼀�ᆠ犨�ᨨ 矄�矄 ᆠ �矄盐矄  ᔴᨨ盐鼀 ᔼᔼ��矄 矄ᨨ鼀矄盐� � ᆠ矄㝐ᆠ  矄鼀 矄� ᔴᨨ盐鼀 ᔼ 犨�  矄鼀 矄� ᔴᨨ盐鼀 ᔼᔼ � �ᆠ泐ᨨ盐 矄犨 泐 ├ � �ᨨ�盐矄�  맔鼀� ��

�  졠 和 ᲼䰘桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰 꾀ᆠ � ᆠᆠ�ᨨ 㡰 꾀ᆠᨨ 矄 ᆠ盐  �矄ᆠᨨ

ᆠ ᨨ  ᨨ犨矄 ᨨ盐�  犨�  矄ᨨ  犨� 㡰 犨��矄鼀ᨨ ⼄㡰 鼀 �泐�矄  �ᆠ盐ᨨ�矄 �  �  犨�  � 犨� ᆠᨨ 矄  ᨨᆠ�泐� 盐 � ᨨ鼀 鼀� �ᆠ �  �ᆠ盐ᨨ   ᨨ 鼀ᨨ�ᨨ

ᔴ㡰 犨��矄ᆠ � 㡰 꾀ᆠᨨ 矄 ᨨ � ᆠᨨ 矄 ᆠ�ᆠ �  ᆠ ᨨ矄 �   矄 �ᆠ�ᨨ

犨   矄ᨨ ᨨ �  � ᨨ  犨�  犨� 㡰 꾀泐ᨨ ᆠᨨ 矄  矄㡰 ᆠ �矄ᨨ ᆠᨨ 矄  鼀 �矄ᆠᨨ

ᆠ ᨨ 鼀� �盐    矄ᨨ  犨�   矄ᨨ  犨� ҈҈ 㝐ᆠ   ᨨᨨ犨� �ᆠᨨ盐鼀 矄 ᲼㝐桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰 �ᆠ�ᆠ� � 㡰 ᔴᨨ 矄 ᆠᨨ矄�ᆠ 盐 � ᨨ鼀泐ᆠ � � ᨨ盐ᨨ 矄泐矄鼀 㡰 �ᆠ�ᆠ� � ⼄㡰 㝐� �ᆠ � 矄 � 盐 � ᨨ鼀泐ᆠ � ᨨ� �犨�  �盐 ᨨᆠ�泐w ᔴ㡰 ᔴᨨ 矄 ᆠ盐 �

㡰 쟼ᆠ�ᆠ �  � 盐ᆠ 㡰 � �� 㡰 �㦨�ᆠᨨ矄w 矄㡰 㝐� �ᆠ �ᨨ鼀ᨨ鼀  8

Comprehension/Passage Based Questions

矄矄�㜠҈ ᔼ  � ᆠ �盐鼀�ᆠ矄�ᆠᨨ 矄 ᆠ盐 I ᨨ犨矄 ᨨ � ᨨ矄�� 㜠 �ᆠ�ᨨ 矄矄 ᨨ犨 �   ��盐  �  犨�    �ᆠ├ 矄矄ᨨ  矄�lw d矄ᆠ�泐 su 꾀盐 � ᨨ鼀鼀� �ᆠ �  B �矄� ᨨ  矄�ᨨ �  ᨨ矄��泐㜠 �ᆠ�ᨨ 盐ᨨ �矄 ᆠ �ᆠ�矄 � ᆠ

WWW.JEEBOOKS.IN

P-209

Moving Charges and Magnetism

  ᆠ�ᨨ ᨨ �  㜠 �ᆠ�ᨨ  �矄矄盐矄� ᆠᆠ盐鼀盐�ᨨ ᨨ ᆠ �ᆠ�矄ᨨ  矄盐 ᆠPQRS  ᆠᨨ ⼄盐 ᨨᨨ矄� ᆠ �矄 ᨨ    ᆠ ᨨᨨ矄� ᨨ PQRS 꾀 ᨨ � �  ᆠ ᨨ �   㜠 �ᆠ�ᨨ  �矄  盐矄 ᨨ  ᔴ � ᆠᆠ盐鼀盐�ᨨ ᆠᨨ � 盐矄盐 � 鼀� �ᆠ ᨨᆠ�矄 ᆠ 泐  ᆠ�ᆠ ᨨᆠ ᆠ盐 �矄矄矄盐鼀 ᨨ盐 � ᨨ鼀泐 �矄�盐 ᨨ  ᆠᨨ矄矄㜠矄ᆠ�ᨨ ᨨ  矄� ᆠ� 泐ᆠᨨ 矄

ᆠ㡰 ᆠ盐 � 犨�҈ 犨��   �ᆠ�ᨨ PQ SR矄ᆠ�泐  h » ҈a 㡰 ᆠ盐 � 犨�҈ 犨��   �ᆠ�ᨨ PQ RS矄ᆠ�泐  h » ҈a ҈� ᔴᨨ 矄� d>>a  ᨨᨨ�矄ᨨ ᨨ盐�矄 �鼀 ᨨ 犨�矄泐  ᨨ鼀 ᨨ矄��ᨨ 矄 ᨨ犨 �   ��盐 ᔼ   ᆠ盐 矄 �    犨�矄  �    ᨨᨨ矄� �ᆠ�ᨨ 矄 ᨨ⼄盐ᨨ  ᨨᨨ�矄 犨ᨨ矄��ᨨ 犨�  矄矄盐鼀    �  盐ᨨ 犨�矄�矄ᆠᨨ 矄  ᨨ ᨨᨨ㡰  ᲼꾀 ҈桌 㡰

ᔴᨨ 矄� 犨ᨨ �  鼀�ᆠ矄�矄 ҈ 㡰ᨨ  矄鼀 鼀� � � 矄 矄鼀犨�  矄w҈ w   �ᆠ├ 矄矄矄d҈ d矄ᆠ�泐 犨ᨨᨨ� 矄⧤  M矄泐鼀鼀�ᆠ泐ᨨᆠ ᨨ   ᨨᨨ矄� ᆠ矄 ᨨ  㜠泐  矄 ��盐㡰V҈ V  ᨨ � �  ᆠ矄犨 K M� 矄�矄҈  矄ᆠ�泐   ᨨ�� ᆠ盐 ᔼ ᨨ犨� � ᨨ盐�  鼀 �   ��  鼀� �ᆠ �  矄 �    ᆠᨨᆠ 矄鼀  矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 ᔼ w҈㦨w d҈㦨d  V㦨V҈ 㡰 ᔼ w҈㦨w d҈㦨   V㦨V҈ ᆠ㡰 ᔼ w҈㦨w d҈㦨d  V㦨V҈ 㡰 ᔼ w҈㦨w d҈㦨d  V㦨V҈ ҈ ᔴᨨ 矄�  犨ᨨ �   鼀�ᆠ矄�矄 ҈  㡰 ᨨ 矄鼀 �鼀 矄�ᨨ 矄  � l犨�  w  �ᆠ├ 矄矄d㡰犨� ᆠ�  矄��矄n҈ n矄ᆠ�泐和�҈�矄ᆠ � 鼀� �ᆠ � B҈ 矄��矄ᆠ � 鼀� �ᆠ � Bᨨ ᨨ � ᨨ矄��泐㜠 �ᆠ�ᨨ 矄   V҈   V   ᨨ � �  ᆠ矄 ᨨ 犨 K M� 矄�矄҈  矄ᆠ�泐꾀矄矄盐鼀� �  ᆠ盐 I�矄 矄鼀 ᨨᨨ  矄�矄 ᆠᨨᆠᨨ�ᨨ 矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 ᔼ B҈㦨B n҈㦨n  V㦨V҈ 㡰 ᔼ B҈㦨B n҈㦨n  V㦨V҈ ᆠ㡰 ᔼ B҈㦨B n҈㦨n  V㦨�V҈ 㡰 ᔼ B҈㦨B n҈㦨n  V㦨V҈ 矄矄�㜠

 ��盐矄 ᨨ犨矄ᆠ�ᆠ盐ᨨᨨᨨ  �盐矄a犨� 犨ᨨᨨ � 犨�矄 盐鼀 ҈ 㡰�   ᨨ    �矄 ᆠ ᨨ ᆠ 犨� ᨨ鼀 ᆠ ᨨ  ᨨᨨ�矄d ᨨᨨ   犨�ᆠ泐� � 矄鼀ᆠ盐 I ᆠ盐 �  ᨨᨨ�矄�

 ᆠᨨ盐 ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ � 矄  ᨨ鼀ᨨ ҈

Q

␔�҈ P ҈

d

d 

S

␔� R

␔   d » a 盐犨�矄 ᨨᨨ盐ᆠ � � ᨨᨨ��矄 ᨨ盐    鼀� �ᆠ � ᨨ   �矄ᨨ  ᨨᨨ�矄 ᨨ  �� hᨨ ᨨᨨᔼ  ᆠ矄 ᲼꾀 ҈桌 㡰 ᆠ盐 � 犨�҈ 犨��   �ᆠ�ᨨ PQ RS矄ᆠ�泐  h » a 㡰 ᆠ盐 � 犨�҈ 犨��   �ᆠ�ᨨ PQ SR矄ᆠ�泐  h » a

ᆠ㡰

m I a d

㡰

m  I  a  d



m I a d m  I  a  d

矄矄�㜠 꾀  ᆠ ᆠᨨ盐 �矄鼀├� �盐矄ᨨ ᨨ犨 盐ᆠᨨ鼀� 矄 ᨨ鼀ᨨ� 矄泐 �� 矄  矄� 矄ᆠ 鼀� � 矄 �  ᨨ鼀鼀� �ᆠ��ᨨ 㡰 矄� 矄 ᨨ ᨨ �盐� 犨泐  ᨨ ᨨ盐 ᨨ 矄�ᆠ├矄 ᔼ 矄 ᨨ 盐矄� � �� 矄 ᨨ  ᨨ矄矄� 盐矄 泐鼀├盐矄ᨨ 鼀� �ᆠ �  ᨨᆠ矄 鼀� �  ᆠᨨ�矄 � �   �盐� 犨泐犨 �ᆠ 矄 矄ᨨ �鼀� 矄ᆠ �  � Ἐ矄 盐 ᆠ�� �矄 矄� 鼀ᨨᨨ �盐� 犨泐ᆠ �ᆠ ᆠ ᆠᨨ㜠 泐 鼀�ᆠ矄盐矄 矄�ᨨ ␔  ᆠ盐 矄矄矄�   ᆠᨨ�矄ᨨ �盐� 犨泐泐�ᆠ鼀� �ᆠ � �矄矄盐犨   盐 ᆠ��ᨨ �  �盐� 犨泐犨 �ᆠ 盐矄 矄 盐  � ᨨ � �盐� 犨泐  � �ᨨ  ⼄盐�鼀 

ᆠ├ᨨ  �ᆠ�ᨨ  �矄ᨨ 泐 鼀�ᆠ矄泐ᨨ犨矄 � ᨨ 鼀ᨨ泐 �� 矄  ҈ ��ᨨ ᨨ  � �矄 盐ᨨ ᲼㜠�㝐桌 㡰 㝐ᆠ  �ᆠ ᨨᆠ 㡰 쟼ᆠᨨ矄�ᆠᆠ�ᨨ

ᆠ㡰 쟼ᆠᨨ矄�ᆠ盐矄�ᨨ 㡰 㝐� �ᆠ盐矄�ᨨ

҈䰘  �矄  �ᨨ 鼀�� 矄�矄 ᲼㜠�㝐桌 㡰 㝐ᨨ �ᆠ�ᨨ

㡰 矄矄ᨨ盐�ᨨ

ᆠ㡰 矄矄犨 㡰 �� � ��ᆠᨨ矄 ҈  ᨨᆠ犨 �ᆠ 鼀├矄鼀�鼀ᨨ ᲼㜠�㝐桌 㡰 ෌��ᨨ  � 㡰 㝐� �ᆠ � ᆠ㡰 盐ᆠ ᨨᆠ矄 㡰 꾀� � 10 Subjective Problems ҈黨 ᔼ 鼀ᨨ� �ᆠᨨ�� ᨨ鼀ᨨ⼄盐ᨨ  ᆠᨨ�ᆠ   矄矄 矄 t = k� 犨 ��矄ᆠ盐  ᨨ盐�  犨�  ├�矄ᆠᨨ 矄  ᆠ �盐ᆠᨨ�ᨨ  � ᨨ鼀 � � 盐鼀ᨨ 盐 矄NA  鼀ᨨ鼀 ᨨ � �I�矄 ᆠ � 鼀� �ᆠ � B � ᲼�㜠㝐├矄桌 㡰 k� 鼀矄ᨨ �� 鼀矄NIA B 㡰   ᨨ矄�ᨨ  ᆠᨨ 矄  ᨨ   矄� � �   ᆠ盐  �  ᨨ 盐ᆠ矄  ᆠ�ᨨ ᨨ p⏌�  ᆠᨨ� ᆠ㡰   鼀 �鼀盐鼀  �  ᨨ盐�  犨 �ᆠ    ᆠᨨ� �矄  ᆠ  � ᆠ � Q �矄 矄矄   ᨨ盐�    ᆠᨨ� 鼀ᨨ矄 � 矄  ᨨ盐矄泐 �� ᨨ   鼀� � �

鼀ᆠ  �ᆠᨨ矄ᆠ��ᨨ 矄㡰  꾀犨 ᨨ  �盐矄R � �ᆠ �Q盐 � ᨨ鼀泐 �矄�盐 ᨨ    �鼀 ᨨ   犨  �矄  ᨨᨨ ᨨ盐  ��  ᨨ� ᨨ ᨨ  ᨨ �矄矄盐矄  泐�� �   矄� 矄� �矄 鼀� �ᆠ � B�矄� 矄矄 ᨨ犨 �  

WWW.JEEBOOKS.IN

EBD_8341 P-210

Physics

��盐 � �� 矄�ᨨ 矄�   矄� �矄T ᔼ   T ├� � 矄�ᨨ ᨨ  矄� �矄   �  鼀 �鼀盐鼀   �盐ᨨᆠ�泐w犨� 犨 �ᆠ  犨 ᆠ ᨨ  ᲼㜠㝐├矄桌 d

w0

㡰 꾀�ᆠᨨ ᆠ �q�矄矄  ᨨ��� 犨�  ur uur ᨨᆠ�泐 v 㦨v �ˆ  �  � 矄  ᨨ盐矄 ᨨᆠ F ᨨ  �ᆠ꾀矄矄盐鼀 矄ᆠ�矄��泐  㡰 ᔼ    盐 � ᨨ鼀鼀� �ᆠ � Bᨨ ˆ �矄�  uur uur 鼀�   ᨨᆠ F҈   F ᨨ  矄鼀�ᆠ�ᆠ矄 uur KLM KNM 盐ᨨ  �     ᨨᆠ F ᨨ  ᨨᨨ  꾀犨�ᨨᨨᆠ泐� �ᆠ盐 ᔼ�矄ᆠ �  x㜠y  矄矄 ᨨ犨 �  �� ᲼҈黨黨҈㜠졔㝐├矄桌

㝐 B

꾀ᆠ盐 ᨨ ҈꾀 ᨨ犨矄ᨨ盐 ᆠᨨ矄  � ᆠ�ᆠ盐�犨 �ᆠ �矄�   ᨨ� ᨨ  矄矄 ᨨ犨 �   ��盐 ᆠ�ᆠ盐� ᆠᨨ 矄�矄矄ᨨ ��  � �ᆠ矄ᨨ  ��r҈㦨鼀 r҈㦨҈鼀쟼ᆠ ᆠ矄盐 矄 矄鼀 � ᆠ  ᲼҈㜠҈㝐├矄桌  D r

C A

r҈



㡰 �  鼀� �ᆠ � ᨨ 盐ᆠ 泐 �矄ᆠ�ᆠ盐�  ᆠ  㡰 꾀 � � �泐ᨨ �矄�� 犨�ᆠ泐� �ᆠ盐 ᨨ ҈꾀�矄矄矄� � ᨨ盐�  ᆠ ᨨ  ᨨᆠ�ᆠ盐� �ᆠ泐犨�   �ᆠ�ᨨ ᨨ  ᆠ盐 � �� ᨨ   ᨨ  ᆠ�ᆠ盐�␔ �矄  ᨨᆠᆠ� �ᨨ

 犨� ᆠ  盐ᨨ ᆠ盐 �  ᆠ�ᆠ盐�䁸 ␔ �矄  ᨨᆠᆠ� �ᨨ  ᆠAC  矄��  矄�鼀 CD 盐ᨨ ᆠ盐  ᆠ 䁸 꾀ᆠ�ᆠ盐ᨨᨨᨨ  �盐矄R�矄 ᨨ � �鼀 �� 矄 矄矄 ᨨ犨 �   ��盐졠 ᨨ  矄鼀�ᆠ�ᆠ矄 KNM㡰�矄�  x㜠z   ᨨ ᨨ  KLM㡰�   y㜠z  犨�  �ᆠ 矄 ᨨ��� ᔴ盐 I�矄 ᨨ犨� �  ᨨ盐� ᆠ ᨨ  矄鼀�ᆠ�ᆠ矄矄矄 ᨨ犨 �  ��盐 ᲼㜠҈㝐├矄桌

҈

҈

 졔턼





泐 졠



 㡰 ᔼ �ᆠ犨� ᆠ �졔Q 鼀矄矄鼀�矄ᆠ  uur  ᆠ  �� ᨨᆠ�泐 v ᨨ �NP 矄 ��盐㡰 � �矄� 矄  ᨨ盐矄ᆠᆠ�ᨨ  㡰 ᔼ   uur    盐 � ᨨ鼀 鼀� �ᆠ � 盐ᆠ�ᨨ  � B 㦨 B�ˆ �矄�  �   ᨨᆠ   ᨨ⼄盐 ᆠ� �ᨨ  ᨨᨨ 盐ᨨ �矄 �   犨ᨨᨨ �犨�矄ᆠ泐� �ᆠ盐 �鼀矄 ᔼ 鼀�  矄鼀 �ᆠ�ᨨ  �ᆠ � ᨨ  ᨨ  㡰  P Q矄ᆠ�泐矄盐ᆠ   泐  �ᆠ盐ᨨ  ᨨ  ᨨ� 矄P Q  ᨨᆠ    �矄 ᆠ ᨨ  � 鼀矄    鼀矄 矄ᆠ�泐 ᨨ鼀ᆠᨨ� ᨨ�   矄 ��盐㡰 ᲼҈黨黨㜠㝐├矄桌

�鼀

鼀  턼  - - - -졠  - - - - 졠 - -  ® - -졠 �꾀 ᔼ꾀 �㡰 꾀 ᆠᨨ 鼀ᨨ� �犨� ᨨᆠ�泐ᨨ 맔҈�鼀⏌矄ᨨ �  ᨨ矄�� 㜠 �ᆠ�ᨨ  � ᆠ矄 ᨨᆠᨨ 鼀� �盐  맔҈ ᨨ�  R �  盐ᨨ ᔼ ��㡰 �  ᨨ矄��ᨨ 矄犨 �ᆠ  � ᨨ � 犨�ᆠ泐� �ᆠ盐 ᨨ 鼀� �盐 �鼀矄鼀泐 ᆠ 矄ᨨ  鼀� �ᆠ� 盐ᆠ�ᨨ R�矄 ᨨ



 ᔼ

㝐 







WWW.JEEBOOKS.IN

P-211

Moving Charges and Magnetism

Answer Key Topic-1 : Motion of Charged Particle in Magnetic Field ҈ ҈҈ ҈ 黨 

ᆠ㡰 㡰 ᆠ㡰 盐㡰 㡰

 ҈   黨

ᆠ㡰 㡰 ᆠ㡰 㡰 㡰

 ҈  ҈ 

㡰 㡰 㡰 ᆠ㡰 㡰

 ҈  

㡰 � ᆠ㡰  㡰 䰘 㡰  㡰 ҈� ᆠ㡰 ҈ 㡰 ҈䰘 㡰 ҈ 㡰 � ᆠ㡰    㡰 䰘 ᆠ㡰  ᆠ 㡰   㡰 � ᆠ 㡰

㡰 黨 㡰 ҈ ᨨ 盐矄㡰 㡰 ҈黨 㡰  㡰 矄㡰  矄㡰  ᆠ㡰 䰘  㡰

Topic-2 : Magnetic Field Lines, Biot-Savart's Law and Ampere's Circuital Law ҈ ҈҈

㡰 㡰

 㡰 ҈ 㡰

 ᆠ㡰 ҈ 㡰

 㡰 ҈ 㡰

� 㡰 ҈� 㡰

 㡰 ҈ 㡰

䰘 ᆠ㡰 ҈䰘 㡰

҈



 ᆠ㡰

 㡰

 㡰

� �㡰

 䰘㡰

䰘  =

 㡰 ҈ 㡰

黨 ᆠ㡰 ҈黨 㡰

҈ 㡰  ᆠ㡰

m ᔼ é ҈ ҈ ù ê ú   㡰 黨 㡰  ë ҈  û

Topic-3 : Force and Torque on Current Carrying Conductor ҈ ҈҈ ҈黨

ᆠ㡰 㡰

盐

 㡰

 ᆠ㡰

 㡰

� 㡰

 ᆠ㡰

䰘 㡰

҈ 㡰

҈ 㡰

҈ 㡰

҈� 㡰

҈ ᆠ㡰

҈䰘 㡰

 㡰

黨 ᆠ㡰

҈ ᆠ㡰

҈ ᔼ ├ˆ ᨨ矄�� �ᆠ�ᨨ

Topic-4 : Galvanometer and its Conversion into Ammeter and Voltmeter ҈



 㡰

҈҈

ᆠ㡰

҈ ᆠ㡰

 ᨨ 盐矄㡰 ҈ 㡰

 ᆠ㡰

� 㡰

 㡰

䰘 㡰

 ᆠ㡰

黨 㡰

҈ 㡰

҈ 㡰

҈䰘 㡰

҈ ��㡰 ҈�  㡰 ҈ ᆠ㡰 ҈䰘 ᆠ㡰 ҈ ᆠ㡰

Topic-5 : Miscellaneous (Mixed Concepts) Problems ҈ 黨 ҈҈ ҈

ᆠ㡰

 㡰

 㡰

 㡰

꾀®⼄®ᔴ®⼄®⼄矄 꾀®®⼄矄ᔴ®⼄矄®⼄矄 㡰

� 㡰



䰘  㡰   㡰

҈ 꾀®®⼄矄ᔴ®⼄矄®⼄矄 ҈  㡰 ҈ ᆠ㡰 ҈ ᆠ㡰 ҈� 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-212

Physics

Magnetism and Matter

19

Topic-1 : Magnetism, Gaus’s Law, Magnetic Moment, Properties of Magnet ҈





꾀矄鼀鼀� ᆠ 犨� �矄 �矄 犨�     � ᨨ   � ᆠ矄 ᨨ⼄盐ᨨ ҈鼀  鼀� �鼀盐鼀 犨ᨨ├ ⼄盐�  ᨨᨨ � ᨨ鼀 �矄 矄 ᨨ 盐 矄⼄盐���盐鼀ᨨ矄��ᨨ �矄[Main Sep.04, 2020 (I)] 㡰 맔҈ 㡰 黨맔҈ ᆠ㡰 䰘맔҈ 㡰 ҈҈䰘맔҈ 꾀ᆠ�ᆠ盐ᆠᨨ� 矄鼀ᨨ鼀 ᨨ � �├�鼀ᨨ盐  泐 �鼀 �矄ᆠ泐� �ᆠ盐 ᨨᨨ 盐ᆠ鼀� �ᆠ 鼀ᨨ鼀 ᨨ 꾀鼀 ᆠᨨ��矄├� ��泐� �ᆠ ᨨ矄��ᨨ    � ᆠ  ᨨ 泐 ᨨ盐   ᨨ� ᨨ  �鼀␔  盐 � ᨨ鼀鼀� �ᆠ � ᨨ  �矄� ᨨ � �ᆠ�矄矄ᨨ� �ᨨ盐 �矄 ᨨ� ᨨ  �鼀  �盐矄  ᆠᨨ�ᆠ⼄盐�矄 ᨨ� � 泐 犨� ᲼Main 和 ᔼᔼ㡰桌 㡰 ҈ 矄҈ 㡰 ҈p 矄҈ ᆠ㡰 p 矄҈ 㡰  矄҈

犨ᨨ鼀� �ᆠ �ᨨ矄 Ӹᆠ 矄�ᨨ d 犨�  � 矄 �ᆠ盐ᨨᆠ ᨨ   �ᨨ鼀ᨨ鼀  ᨨ Ӹ�矄犨�ᆠ ᨨ 꾀�ᆠᨨ ᆠ �q�矄矄矄� �  ᨨ盐�  �鼀� ᨨ�  �q㦨� 犨�   ᨨ� ᨨ  � 矄矄 ᨨ犨 �  ��盐␔ 犨ᨨ盐  鼀� �盐 ᨨ ᨨᆠᨨ  �ᆠ � 矄 䁸 d �矄鼀盐ᆠ � 

  �鼀 矄�ᨨ 矄ᨨ   �ᨨ㡰 ᲼Main 꾀�҈黨ᔼᔼ桌



�



䰘

꾀 鼀�  ᨨ  ᨨ 鼀� �ᆠ 鼀ᨨ鼀  ҈ - �ˆ  꾀㜠鼀 �矄 ᆠ � �鼀泐� �鼀� �ᆠ �  �ˆ ᆠᨨ矄w㡰犨   㦨 ҈  矄  w 㦨 ҈�  ⏌矄 犨ᨨ├ ᨨ  ᨨ 矄� �  �ᆠ�ᨨ ᨨ  鼀� �ᆠ鼀ᨨ鼀 㦨҈ 矄ᆠᨨ  �矄 ᲼Main ҈  ҈黨ᔼ桌 㡰 ҈ 㡰 䰘 ᆠ㡰  㡰 ҈ 꾀鼀� �ᆠ �ᨨ�矄ᆠ 盐ᨨ 泐犨ᨨ鼀� �ᆠ � 矄 犨 �ᆠ � ᆠ�  ᨨᆠ ᨨ   �ᨨ 䰘� 졠 ᨨ   � 矄 矄鼀� �盐 ᨨ ҈�鼀   �ᨨ� 矄 矄⼄盐���盐鼀  �ᨨ  犨�  �矄 �   鼀� � 盐ᨨ  ᨨ  �  � 鼀 㡰�矄ᆠᨨ矄ᨨ ᲼Main 졠 � 꾀�黨҈桌 㡰 ҈ 㡰 ҈҈ ᆠ㡰  㡰 ҈ 꾀�ᆠ鼀ᨨ �矄ᨨ ᨨ�  矄 �盐矄ᆠ鼀 �ᨨ 盐鼀 ᨨ 盐 矄ᔼᆠ�矄ᆠ盐 ᨨ ҈�꾀ᔼ ��矄⼄盐� ᨨ r 鼀� ᨨ  矄鼀矄�  鼀� � �ᨨ  㝐  鼀� �ᆠ uur 鼀ᨨ鼀 ⏌ᨨ盐鼀㡰   㝐 �矄 ᲼Main졠 � 꾀�҈҈�桌 㡰 p꾀鼀҈ 㡰 p꾀鼀҈ ҈ ᆠ㡰 꾀鼀 㡰 꾀鼀҈ 꾀ᆠ盐 ᆠ泐� �ᨨᨨ�矄ᆠ � 盐 � ᨨ鼀鼀� �ᆠ � �  ᨨ盐 �  ᨨ� �ᨨ 矄ᔼᔼᔼᔼᔼᔼᔼ �  鼀�   ᆠ矄� �ᨨ ᨨ ᨨ �쟼 �泐᲼和桌

ᔼ æ m ö M ´ qv ç ÷ 㡰 è p ø d  㡰   æm ö M æ m ö M ´ qv ´ qv ç ÷ çè ÷ø  è ø  p ᆠ㡰 㡰 p d  d  

( )

( )

( )







ᔼᔼ



ᔼᔼᔼ



WWW.JEEBOOKS.IN



P-213

Magnetism and Matter 

6

ᔼ





㡰 ᔼ>ᔼᔼᔼ>ᔼᔼ>ᔼ 㡰 ᔼ>ᔼᔼ>ᔼᔼᔼ>ᔼ ᆠ㡰 ᔼ>ᔼ>ᔼᔼ>ᔼᔼᔼ 㡰 ᔼᔼᔼ>ᔼ>ᔼ>ᔼᔼ

鼀� �ᆠ � � 矄 盐ᨨ鼀� ᆠᨨᆠ泐 矄 ᨨ犨 �

᲼和桌 N

N

MCQs with One or More than One Correct Answer

҈� 꾀ᨨ �ᆠ盐 ᆠ泐� �犨�ᆠ泐� �ᆠ盐 ᔼ҈矄盐ᆠ   ᔼ҈�矄 ᨨ犨� �ᨨ盐 ᨨ鼀  ᨨ �矄ᆠ O꾀 矄 泐矄ᆠ盐 I�矄 ᨨ犨� ��  ᨨᨨABCD ᲼㜠�㝐҈桌 ᔴ  ᔼ 졠

졠Ἐ

ᔼ҈

㡰

㡰 S

S

N

N

ᆠ㡰

㡰 S

黨

҈



S

꾀�ᆠᨨ ᆠ �⼄ 鼀矄矄鼀鼀ᨨ矄� ᆠ�ᆠ盐ᨨ� ᨨ  �盐矄犨�  �盐矄  w  �ᨨᨨ  鼀� �盐  ᨨ �矄鼀� �ᆠ鼀ᨨ鼀 ᨨ ᨨ �矄 �盐鼀ᨨ鼀 盐鼀  矄 ᨨ

᲼和桌 㡰 w  q 㡰 w q m ᆠ㡰 q m 㡰 w  m

犨ᨨ�ᆠ矄ᆠ ᨨ 鼀矄矄鼀 ᆠ �qᆠ  ᨨ 犨ᨨ 矄ᨨ �� ��� ᨨ ᨨ  � R ᨨ �矄 ᨨ  ᆠᨨ 矄  �盐 矄 ᨨ盐  �ᆠ盐  �矄矄矄� � ᨨ盐� �矄ᆠ  �ᨨᨨ  鼀� �盐 矄 ᨨ  鼀� �ᆠ鼀ᨨ鼀  ᨨ  矄泐矄鼀  �矄  �盐 鼀ᨨ鼀 盐鼀ᨨ盐 ᆠ ᨨ  ᨨ �矄᲼҈黨黨和㜠㝐├矄桌 q q q q 㡰 ᆠ㡰 㡰 m m m pm 꾀ᆠᨨ 盐ᆠ� �ᆠ�ᆠ盐ᨨᨨᨨ  �盐矄rᆠ�矄ᆠᨨ 矄  r ᆠ盐 �ᔼ�矄ᆠ � 盐 � ᨨ鼀鼀� �ᆠ �  B 矄盐ᆠ r   B �矄 �ᆠ盐 ᨨ  ᨨ  ᨨᨨ  鼀� �ᆠ ᨨᆠᆠ� �ᨨ  ᨨᨨ�矄 ᲼҈黨㜠҈㝐├桌 㡰 �r B 㡰 p �r B ᆠ㡰 ᨨ 㡰 p �r B 꾀鼀� �ᆠ  �矄├�  ᨨ 盐 � ᨨ鼀鼀� �ᆠ �  ᔼ � ᆠ矄 ᲼҈黨㜠㝐├矄桌 㡰  ᨨᆠ ᨨ⼄盐 㡰  ᨨᆠ盐 ᨨᨨ⼄盐 ᆠ㡰 ᨨ⼄盐盐 ᨨ ᨨᆠ 㡰 �  ᨨᆠ ᨨᨨ⼄盐

㡰

҈҈

҈

҈

҈

4 Fill in the Blanks ᔼ   泐 ᨨ�  ᨨ鼀  ᆠᨨ  鼀ᨨ矄�    ᨨ� ᨨ  �盐矄 � 处 鼀├� � ҈҈ ᨨ盐�ᨨ 矄  矄ᆠᨨ   鼀� �ᆠ鼀ᨨ鼀 矄矄ᨨᆠ� 犨�  ᨨ�鼀ᨨ�ᨨ ᨨ  ᆠᨨ �矄 ᲼҈黨㜠㝐├矄桌 꾀犨�ᨨ  � L鼀ᆠ泐� �ᆠ盐 �鼀�矄  �   ᨨ鼀ᨨ ᆠ�ᆠ 鼀� �盐 ᨨ �矄鼀� �ᆠ 鼀ᨨ鼀 �矄� MKS盐 �矄 ᲼҈黨䰘㜠㝐├矄桌

㡰    ᨨᆠ�矄 ᨨ  㡰   ᨨ⼄盐�矄 ᨨ ᆠ㡰 矄矄  ᨨ鼀O ᨨᨨ犨�ᨨ� ᆠᨨᆠ├犨�矄ᨨ � OOἘ �矄 㡰 矄矄  ᨨ鼀O ᨨᨨ犨�ᨨ�  �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ ᨨ �OOἘ �矄 ҈  ᨨᨨ犨� � � � ᆠ  矄  ᲼㜠�㝐҈桌 㡰 � 盐ᆠ ᆠ�ᆠ � 㡰 鼀� ᨨ矄�ᆠ � ᆠ㡰 ���ᨨ  � ᨨ 鼀矄矄矄 㡰 ᆠᨨ矄�ᆠ � 10 Subjective Problems ҈䰘 꾀盐 � ᨨ鼀ᆠᨨ 矄 鼀� �ᆠ � �矄 �ᆠ   � ᨨ � ᨨ x �矄�  xy㜠 PQRS �矄��� 矄⼄盐 犨� 鼀ᆠ泐� �矄 泐ᆠ盐 I犨� �矄ᆠ   ᨨ��� O꾀�鼀t㦨  鼀�矄矄�  ᨨ矄��ᨨ

矄矄 ᨨ犨 �  ��盐犨� �矄矄� 矄ᨨ x y  矄쟼ᆠ 矄� ᨨ   鼀�矄ᨨ 鼀矄矄M  � L 泐  













㡰 ␔ �矄 ᨨ⼄盐t ᨨ盐Oᆠ� �ᨨ   鼀 盐 ᨨ 鼀� �ᆠ � 䁸 㡰 �   �泐犨 �ᆠ   鼀ᨨ矄盐   ᆠ�ᨨ ᨨ  �矄ᨨ⼄盐� 矄 ᨨ� ᨨ �鼀Dt   �矄ᨨ盐 �矄ᨨ�ᨨ ᨨᆠᆠ盐矄 Dt�矄矄ᨨ矄 ᨨ   泐��ᨨ �  ᨨ⼄盐 盐� � �矄� 鼀泐

�ᆠ 㡰෌�  鼀ᨨ鼀 ᨨ � �ᨨ   鼀 ᨨ盐  �矄 ᨨ盐� �矄ᆠ  �ᆠ盐ᨨ�矄    �矄 ML  ᲼҈黨黨㜠㝐├矄桌  ҈ 꾀  ᆠᨨ  �    �ᨨ盐  矄 ᨨ  泐 ᨨ�  ᨨ鼀 �矄 ᨨ� ��  �ᆠᨨᆠ├㜠犨�矄 �ᆠ�ᨨ � ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄R ᲼҈黨黨㜠�㝐├矄桌 �㡰 졠�   矄矄�ᨨ  ᨨ ᨨ�鼀� �ᆠ �ᨨ 鼀ᨨ鼀 ᨨ  ᆠᨨ 

WWW.JEEBOOKS.IN

EBD_8341 P-214

Physics

(ii) The ur atom is placed in a uniform magnetic induction B such that the plane-normal of the electron-orbit makes an angle of 30° with the magnetic induction. Find the torque experienced by the orbiting electron.

19. A bar magnet is placed with its north pole pointing north and its south pole pointing south. Draw a figure to show the location of neutral points. [1979] 20. A bar magnet with poles 25 cm apart and of strength 14.4 amp-m rests with centre on a frictionless pivot. It is held in equilibrium at an angle of 60° with respect to a uniform magnetic field of induction 0.25 Wb/m2, by applying a force F at right angles to its axis at a point 12 cm from pivot. Calculate F. What will happen if the force F is removed? [1978]

Topic-2 : The Earth Magnetism, Magnetic Materials and their Properties 1 1.

2.

3.

4.

MCQs with One Correct Answer

5.

An iron rod of volume 10–3 m3 and relative permeability 1000 is placed as core in a solenoid with 10 turns/cm. If a current of 0.5 A is passed through the solenoid, then the magnetic moment of the rod will be : [Main Sep. 05, 2020 (II)] (a) 50 × 102 Am2 (b) 5 × 102 Am2 (c) 500 × 102 Am2 (d) 0.5 × 102 Am2 A paramagnetic sample shows a net magnetisation of 6 A/ m when it is placed in an external magnetic field of 0.4 T at a temperature of 4 K. When the sample is placed in an external magnetic field of 0.3 T at a temperature of 24 K, then the magnetisation will be :[Main Sep. 04, 2020 (II)] (a) 1 A/m (b) 4 A/m (c) 2.25 A/m (d) 0.75 A/m A perfectly diamagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. r The whole system is placed in a uniform magnetic field B. Then the field inside the paramagnetic substance is : [Main Sep. 03, 2020 (II)]

r (a) B P (b) zero r r (c) much large than | B | and parallel to B r r (d) much large than | B | but opposite to B Magnetic materials used for making permanent magnets (P) and magnets in a transformer (T) have different properties of the following, which property best matches for the type of magnet required? [Main Sep. 02, 2020 (I)] (a) T : Large retentivity, small coercivity (b) P : Small retentivity, large coercivity (c) T : Large retentivity, large coercivity (d) P : Large retentivity, large coercivity

The figure gives experimentally measured B vs. H variation in a ferromagnetic material. The retentivity, co-ercivity and saturation, respectively, of the material are: [Main 7 Jan. 2020 II] (a) 1.5 T, 50 A/m and 1.0 T (b) 1.5 T, 50 A/m and 1.0 T (c) 150 A/m, 1.0 T and 1.5 T (d) 1.0 T, 50 A/m and 1.5 T 6.

7.

A paramagnetic material has 1028 atoms/m3. Its magnetic susceptibility at temperature 350 K is 2.8 × 10–4 . Its susceptibility at 300 K is: [Main 12 Jan. 2019 II] (a) 3.267 × 10–4 (b) 3.672 × 10–4 (c) 3.726 × 10–4 (d) 2.672 × 10 –4 A paramagnetic substance in the form of a cube with sides 1 cm has a magnetic dipole moment of 20 × 10–6 J/T when a magnetic intensity of 60 × 103 A/m is applied. Its magnetic susceptibility is: [Main 11 Jan. 2019 II] (a) 3.3 × 10–2 (b) 4.3 × 10 –2 (c) 2.3 × 10–2 (d) 3.3 × 10–4

WWW.JEEBOOKS.IN

P-215

Magnetism and Matter

8.

9.

A bar magnet is demagnetized by inserthing it inside a solenoid of length 0.2 m, 100 turns, and carrying a current of 5.2 A. The coercivity of the bar magnet is: [Main 9 Jan. 2019 I] (a) 285 A/m (b) 2600 A/m (c) 520 A/m (d) 1200 A/m The B-H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000 turns/cm.. The current that should be passed in the solenoid to demagnetise the ferromagnet completely is: [Main Online April 15, 2018]

12. The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 ´ 103 Am -1. The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetized when inside the solenoid, is: [Main 2014] (a) 30 mA (b) 60 mA (c) 3 A (d) 6 A 13. Three identical bars A, B and C are made of different magnetic materials. When kept in a uniform magnetic field, the field lines around them look as follows:

B(T)

A

C

B

2, 0

1, 0

H(A/m)

–200 –100 100 200 –1, 0 –2, 0

10.

(a) 2 mA (b) 1 mA (c) 40 µA (d) 20 µA Hysteresis loops for two magnetic materials A and B are given below : D

B

H (A)

11.

H (B)

These materials are used to make magnets for elecric generators, transformer core and electromagnet core. Then it is proper to use : [Main 2016] (a) A for transformers and B for electric generators. (b) B for electromagnets and transformers. (c) A for electric generators and trasformers. (d) A for electromagnets and B for electric generators. A fighter plane of length 20 m, wing span (distance from tip of one wing to the tip of the other wing) of 15m and height 5m is lying towards east over Delhi. Its speed is 240 ms–1. The earth's magnetic field over Delhi is 5 × 10–5T with the declination angle ~0° and dip of q such that sin q 2 = . If the voltage developed is VB between the lower and 3 upper side of the plane and VW between the tips of the wings then VB and VW are close to: [Main Online April 10, 2016] (a) VB = 40 mV; VW = 135 mV with left side of pilot at higher voltage (b) VB = 45 mV; VW = 120 mV with right side of pilot at higher voltage (c) VB = 40 mV; VW = 135 mV with right side of pilot at higher voltage (d) VB = 45 mV; VW = 120 mV with left side of pilot at higher voltage

Make the correspondence of these bars with their material being diamagnetic (D), ferromagnetic (F) and paramagnetic (P): [Main Online April 11, 2014] (a) A « D, B « P, C « F (b) A « F, B « D, C « P (c) A « P, B « F, C « D (d) A « F, B « P, C « D 14. The mid points of two small magnetic dipoles of length d in end-on positions, are separated by a distance x, (x > > d). The force between them is proportional to x–n where n is: [Main Online April 9, 2014] N

S

N

S

x

(a) 1 (b) 2 (c) 3 (d) 4 15. Two short bar magnets of length 1 cm each have magnetic moments 1.20 Am2 and 1.00 Am2 respectively. They are placed on a horizontal table parallel to each other with their N poles pointing towards the South. They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultand horizontal magnetic induction at the mid-point O of the line joining their centres is close to (Horizontal component of earth.s magnetic induction is 3.6× 10.5Wb/m2) [Main 2013] (a) 3.6 × 10.5 Wb/m2 (b) 2.56 × 10.4 Wb/m2 (c) 3.50 × 10.4 Wb/m2 (d) 5.80 × 10.4 Wb/m2 16. The earth’s magnetic field lines resemble that of a dipole at the centre of the earth. If the magnetic moment of this dipole is close to 8 × 1022 Am2, the value of earth’s magnetic field near the equator is close to (radius of the earth = 6.4 × 106 m) [Main Online April 25, 2013] (a) 0.6 Gauss (b) 1.2 Gauss (c) 1.8 Gauss (d) 0.32 Gauss

WWW.JEEBOOKS.IN

EBD_8341 P-216

Physics

Topic-3 : Magnetic Equipment 1 ҈

MCQs with One Correct Answer

꾀� ��矄 盐 �ᨨ  �ᔼᆠ ᨨ矄ᆠ�犨� ᨨ盐矄�� � ᨨ矄� � � �㡰� �矄 犨� �鼀�ᨨ T҈  ��㡰ᆠ├   ᨨ �  �ᆠ�ᨨ  �ᆠ盐ᨨ�矄 犨�  �ᨨ T �ᨨ 㡰

 

T҈ 犨� ᲼㝐� 和� ᔼᔼ㡰桌 T  㡰 

   꾀鼀� �ᆠᆠᨨ鼀矄矄  ᨨ矄ᆠ�矄�鼀矄鼀� 盐 ᆠ犨   ��矄�ᨨ �鼀矄鼀� 盐 犨   ��矄ᨨᔼ ҈ 矄ᆠ�泐 ᨨ 鼀� �ᆠ �  盐ᨨ    犨ᨨᆠ矄 

 �ᨨ҈⏌�矄矄�� 泐 ᲼㝐� ҈꾀�҈黨ᔼ桌 㡰 ҈ 㡰 䰘 ᆠ㡰  㡰  ᆠ㡰











꾀 ᨨᨨ 矄ᨨ� ᆠ泐� ᨨ 矄鼀鼀矄矄  �盐矄 鼀  ᨨ   鼀   鼀� �ᆠ 鼀� 犨�   � 鼀� �ᆠ鼀ᨨ鼀 ᨨ �矄ᆠ� 矄盐  鼀� �ᆠ鼀ᨨ鼀 ᨨ  ᨨᨨ�矄犨�ᆠᨨ 矄ᨨ� ᆠ泐� 

泐ᆠ �  盐 � ᨨ鼀鼀� �ᆠ � � 矄盐ᆠ   鼀

  �鼀� �ᆠ鼀ᨨ鼀 矄鼀├矄鼀 � 犨�    �  ᔼ    ᨨ矄ᆠ��ᨨ  �ᨨ 矄 ᨨ  ᨨᨨ  ᆠ泐�     ᆠ矄ᆠ�泐    ᲼㝐�  ҈  ҈黨 ᔼᔼ桌 㡰 㦨 ᆠ 㡰 㦨 ᆠ ᆠ㡰 㦨҈� ᆠ 㡰 㦨� ᆠ 꾀鼀� �ᆠ  ᨨ 鼀� �ᆠ鼀ᨨ鼀 䰘맔҈꾀鼀  鼀ᨨ鼀 ᨨ � �䰘�맔҈├�鼀�矄 ᨨ鼀� �矄�鼀 鼀ᨨ �ᆠᨨ矄ᆠ��ᨨ 矄� 鼀� �ᆠ � ᨨ ҈  �鼀 ├  ᨨ҈ᆠᨨ鼀ᨨ矄ᆠ��ᨨ 矄�矄 ᲼㝐� ҈䰘桌 㡰 黨矄 㡰 䰘矄 ᆠ㡰 �矄 㡰 黨矄

Topic-4 : Miscellaneous (Mixed Concepts) Problems 8

�  B҈犨 �ᆠ ᨨ   ᨨᨨ犨� �� 矄矄 ᨨ犨矄  ᆠᨨᆠ��ᨨ ᨨ  犨�  �  矄 � 矄䁸

Comprehension/Passage Based Questions

꾀和和꾀෌E 쟼ᆠ�ᆠ 矄�矄 ᆠ ᨨ  ᆠ�  鼀�矄 ├ ᨨ犨  矄 矄盐ᆠᨨ 盐ᆠᨨ矄 ᆠ  �矄 盐泐 ᨨ鼀  ᨨ ᨨ 盐 ᨨ ᨨ矄 �鼀盐�矄ᨨ犨 ᨨ犨ᆠ��ᆠ鼀盐 TC 㡰꾀 � 矄� �ᨨ泐ᨨ 矄盐ᆠᨨ 盐ᆠᨨ矄�矄  � ᆠ��ᆠ鼀盐ᆠᨨ鼀矄矄鼀  TC 㡰�  泐ᆠ � 鼀� �ᆠ � � ᆠ��ᆠ鼀盐TC B㡰�矄 盐 ᆠ�ᨨ

ᨨ  鼀� �ᆠ � 矄 �     ᆠᨨ TC B㡰ᨨ  �矄矄 ᨨ犨 �   ��盐 ᲼҈桌 TC B㡰

㡰

㡰

ᆠ㡰



TC 㡰



҈

졠 B ᔼ  � 矄ᨨ犨 矄�矄 ᆠRᨨ 矄盐ᆠᨨ 盐ᆠᨨ �矄矄 ᨨ犨 矄 盐 ᆠ�ᨨ ᨨ �矄鼀盐T ᨨ犨ᨨ �   鼀� �ᆠ � 矄B҈ 矄ᨨ� � 㡰 B 矄  � 㡰ᔼ B�矄

꾀矄盐ᆠᨨ 盐ᆠᨨ 矄TC 㡰㦨҈⧤␔  鼀� �ᆠ � ᨨ 䰘� 矄�矄� �矄TC ᆠ矄矄ᨨ䰘�⧤ ᨨ  �矄鼀�ᨨ ᆠ   � �泐矄泐 犨 

㡰 B㦨� 矄TC 㡰㦨⧤ 㡰 B㦨� 矄䰘�⧤TC 㡰҈⧤ ᆠ㡰 B㦨҈ 矄䰘�⧤TC 㡰҈⧤ 㡰 B㦨҈ 矄TC 㡰㦨䰘⧤

WWW.JEEBOOKS.IN

P-217

Magnetism and Matter

Answer Key Topic-1 : Magnetism, Gaus's Law, Magnetic Moment, Properties of Magnet ҈ ᆠ㡰

 㡰

҈҈ ᆠ㡰

҈ 㡰

 㡰

 ᆠ㡰

҈ ҈�맔҈꾀鼀㡰

� 㡰 ҈

 ᆠ㡰

䰘 㡰

 㡰

黨 ᆠ㡰

҈ 㡰

�L 㡰 ҈� ᆠ㡰 ҈ ᆠ 㡰 π

Topic-2 : The Earth Magnetism, Magnetic Materials and their Properties ҈ 㡰

 㡰

 㡰

 㡰

� 㡰

 㡰

҈҈ 㡰

҈ ᆠ㡰

҈ 㡰

҈ 㡰

҈� 㡰

҈ 㡰

䰘 㡰

 㡰

黨 㡰

҈ 㡰

Topic-3 : Magnetic Equipment ҈ 㡰

 ᨨ 盐矄㡰  㡰

 ᆠ㡰

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈ 㡰

 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-218

Physics

Electromagnetic Induction

20

Topic-1 : Magnetic Flux, Faraday's and Lenz's Law MCQs with One Correct Answer

1 ҈

҈㡰

꾀矄鼀鼀� �矄鼀ᨨ  ᨨ盐� ᆠᨨ�ᆠᨨ 矄  矄  ᨨ鼀ᨨ  ᨨ ᨨ ␔ �ᆠ ᨨ   ᨨᨨ犨� � 矄�矄ᨨ ᨨ矄�ᨨ 矄犨�矄 ᨨ  � ᨨ鼀G ᆠ  ᆠᨨ矄矄 ᆠᨨ�䁸 ᲼㝐� 和 ᔼ㡰桌

 ᆠ

鼀� 



㡰

®

꾀 ��ᆠᨨᨨ � �矄�矄 ᆠRᨨ 矄鼀�鼀ᨨ �矄a  矄鼀�鼀� ᨨ �矄b�矄ᆠ � 鼀� �ᆠ � 矄矄 ᨨ犨

�   ��盐ᔼ  ᨨᨨ�矄ᨨ ᨨ盐 x㜠 �矄犨�  �盐 ⼄盐 ᆠ泐w �ᨨ犨ᨨ矄矄�  ᨨᨨ 盐ᨨᨨ盐 � ��矄 ᲼㝐� 和 ᔼ㡰桌

B

z

ᨨ矄��ᨨ 矄矄 ᨨ犨  矄ᆠ� ҈㡰 鼀� 矄 泐 㡰鼀� �矄ᆠᨨ鼀泐� 矄�   㡰鼀� 矄 � ҈㡰

㡰

®





G

㡰

b

x

㡰

a y

y ®

㡰

҈㡰

㡰 ®

㡰 ®

㡰

p  a  b  B  w R

㡰 ᨨ

ᆠ㡰

pabBw R



㡰



҈㡰 ᆠ㡰

®

®

㡰

x

㡰 ®

p a  b B  w R

꾀 盐 � ᨨ鼀 鼀� �ᆠ �  B  �矄矄 �   �ᆠ�ᨨ

 �ᆠ盐 ᨨ    ᨨ  矄⼄盐 ᨨᨨ 鼀  ᨨ  鼀犨� 犨� 矄 �鼀ᨨ 鼀鼀 ᨨ  � ᨨ ᆠ鼀 鼀� �ᆠ � ᆠ  �矄犨� �鼀 矄 泐dB/dt㦨 矄҈ � 盐ᆠ  ᆠ盐  �

  ᨨᨨ �矄 ᆠᨨ矄 ᨨ 矄�矄��泐ᨨ   鼀 犨� �矄 ҈맔҈W 鼀㡰 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 �꾀 㡰 꾀 㡰 ҈꾀 ᆠ㡰 꾀

WWW.JEEBOOKS.IN

P-219

Electromagnetic Induction



�



䰘



꾀�鼀t㦨鼀� �ᆠ � ᨨ ҈෌盐矄矄�矄矄矄� �  �ᆠ盐泐 ᨨ盐�    �  泐 ᆠᨨ矄 ᨨᨨ矄 ᨨ犨 �   ��盐ᔼ  鼀� �ᆠ �  盐ᆠ矄 � 泐ᨨ�෌盐矄矄�    �矄  � 盐ᆠ 쟼㝐 �  ᨨᨨ�矄 ᲼㝐�  ᔼ桌

㡰 �m 㡰 m ᆠ㡰 m 㡰 m ᔴᨨ 矄� ᆠ�ᆠ盐ᆠᨨ�ᨨ 犨�ᆠ泐� �ᆠᨨ 矄 ᆠ盐 I ᨨ鼀� �鼀� �ᆠ �ᨨ 鼀� �ᆠ 盐  ᨨ盐� 

� � �  ᆠᨨ � 矄 ᆠ�ᆠ盐ᆠᨨ�  ᆠ盐 � �  ᆠ�ᆠ盐ᆠᨨ��矄�� 泐f�  鼀� �ᆠ 盐  ᨨ盐�  ᨨ  ᆠ�ᆠ盐ᆠᨨ��矄�� 泐f␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ �矄ᆠᨨᆠ䁸 ᲼㝐� 䰘 ᔼ桌 㡰 f�㦨f 㡰 f�>f ᆠ㡰 f�f 㡰 f�㦨f 꾀ᨨ �矄ᨨ ᨨ� ᨨ  �盐矄Rᆠ�矄�鼀 t㡰㜠    ᆠ盐 I t㡰㦨It t㡰꾀� �ᨨ  �盐矄R�矄ᆠ ᆠᨨ �泐

�矄鼀� 盐� � �鼀� £t£҈  � 盐ᆠ ᆠ盐  IR㡰  � 盐ᆠ EMF VR㡰�  � � ᆠ  �矄 ᲼㝐� 䰘 ᔼ桌 㡰 �ᆠ�ᨨ ᨨ IR鼀� 矄盐 ᆠ  �  VR�矄鼀 �鼀盐鼀 t㦨� 㡰 꾀t㦨� �ᆠ�ᨨ ᨨ IR 矄矄 VR�矄鼀 �鼀盐鼀 ᆠ㡰 �ᆠ�ᨨ ᨨ IR鼀� 矄盐 ᆠ  �  VR�矄 ᨨt㦨� 㡰 꾀t㦨� �ᆠ�ᨨ ᨨ IR矄矄 VR�矄 ᨨ 꾀 ᨨᨨᨨ 犨�ᨨ矄� 盐 � ᨨ鼀鼀� �ᆠ �  ᔼ ��泐t㦨  ᨨ  ᨨᨨ�矄 �ᆠ盐ᨨ  鼀� �ᆠ � ᔼ �ᨨ矄犨� �ᨨ ᨨ ҈矄ᨨ盐

 �矄� �矄    鼀� �盐 ᨨ � 盐ᆠ 鼀 犨� 鼀 �鼀盐鼀 鼀� �鼀盐鼀矄ᆠ�泐᲼㝐� 䰘 ᔼᔼ桌 㡰 �矄 䰘�矄 㡰 �矄 �矄 ᆠ㡰 �矄 䰘�矄 㡰 �矄 ҈矄 꾀 泐 ᨨ � 矄ᨨ ᨨ�  ᨨ   �盐矄  �矄 ᆠ泐� � ᆠ盐  ᔼ 㡰㦨├at k >㡰矄 盐 ᆠ�ᨨ ᨨ �鼀 t >㡰ᔴᨨ盐  ᆠᨨᆠ├犨�矄 ᆠ盐  �矄 ├  ᨨ  ᨨ矄�� 꾀 ᆠ�ᆠ盐 ᆠᨨ 盐ᆠ� �ᆠᨨ�ᨨ  �盐矄 �矄ᆠ �  ⼄盐ᨨ�  ᨨ  矄ᨨ ᨨ�  ᆠᨨ ᆠ �ᆠ犨�  矄ᨨ ᨨ� 

ᆠ盐 � 盐ᆠ �  ᨨ盐ᆠᨨ��矄ᆠᨨᆠ泐 �ᆠ  矄 盐 ᆠ�ᨨ ᨨ �鼀泐 ᲼㝐� 黨꾀҈黨ᔼᔼ桌 㡰

 矄  � 盐ᆠ  鼀  ᨨ   ᆠᨨ� �矄 � ᨨ矄 ␔     ᆠ盐 � ��矄ᆠ  � 盐 �� ᨨ鼀 ᨨ鼀҈꾀ᨨ� 꾀� ҈矄  ᆠ  ��    �泐ᨨ  � 盐ᆠ ᆠ�矄 ᲼㝐� 黨 ҈黨ᔼᔼ桌 㡰 䰘 㡰 䰘� ᆠ㡰 � 㡰 䰘� ҈ 꾀ᆠᨨ 盐ᆠ� �ᆠ�ᆠ盐ᨨᨨ鼀 ᨨ  � 犨� 矄 �맔҈鼀 矄�矄 ᆠ҈Wᔼ�矄ᆠ  �ᆠ盐 ᨨ�鼀   鼀� �ᆠ �  㡰㦨  㡰矄�  �p㡰

  ᆠ � ᨨ犨� � ᨨ盐�  ᨨᨨ 盐� �㦨 ᲼㝐� 黨 ҈黨ᔼ桌 矄 㦨҈鼀矄�矄ᆠᨨ矄ᨨ 㡰 ҈鼀ᔴ 㡰 䰘鼀ᔴ ᆠ㡰 ҈鼀ᔴ 㡰 鼀ᔴ ҈҈ ᔼ ᆠᨨ�ᨨ 矄�矄 ᆠ҈ W ᆠ盐 �矄� 盐ᆠ 泐ᆠ  �� �  鼀� �ᆠ 盐  ᨨ盐� �矄矄 ᨨ犨 �    ��盐  鼀� �盐 ᨨ ᆠ  ��  盐  ᨨ盐�  ᆠᨨ��矄 ᲼㝐� ҈䰘桌 黨

㡰 �␔ 㡰 䰘�␔ ᆠ㡰 ␔ 㡰 �␔ ҈ 꾀ᆠᨨ 盐ᆠ� �鼀ᆠ�ᆠ盐犨�ᨨᨨᨨ  �盐矄�矄ᆠ  �ᆠ盐ᨨ鼀� �ᆠ � 犨 �ᆠ �矄犨� �鼀矄 㦨  

-

t

犨  tᆠᨨ 矄 矄�鼀㦨

ᔼ  矄�矄 ᆠᨨ  ᨨᨨ�矄     �  �

 ᨨᨨ ᨨ ��鼀  ® ¥㡰 �矄錐 ᲼㝐� 졠 � 꾀�҈҈桌 㡰

p     t

㡰

p     t

p     p     㡰 t t ҈ ␔  ᆠ盐 � ᆠᨨ�ᆠ  �矄 ᨨ鼀�꾀ᨨ꾀� ҈矄 �ᨨ�ᨨ ��矄ᨨ 盐ᆠ  矄 㜠� 盐ᆠ ᆠ ᨨ  ᆠᨨ��矄 ᲼㝐� 졠 � 꾀�҈҈�桌 㡰  㡰 䰘 ᆠ㡰  㡰 ҈䰘 ҈ ��盐矄 ᨨ犨矄ᆠ�ᆠ盐ᨨ  �盐矄 犨 盐 � ᨨ鼀

ᆠ㡰

®

鼀� �ᆠ �   �矄 �ᨨ� �� ᨨ   ᨨ   � ᆠ矄� �� 鼀� �盐 ᆠᨨ 矄 

㡰

ᆠ㡰



ᔼ    ᆠ矄 犨 �ᆠ  ᨨ    ᨨᨨ犨� � � 矄 犨

矄ᆠ 鼀�ᆠ泐ᆠᨨᆠ泐矄 ᨨ犨矄 ��ᨨ ᨨ  � 盐ᆠ ᆠ�ᆠ � 쟼 㡰䁸 ᲼졠 � 꾀�҈黨҈桌

WWW.JEEBOOKS.IN

EBD_8341 P-220

Physics





㡰

ᆠ㡰













ᆠ㡰



҈�

҈

꾀ᆠ�ᆠ盐ᨨᨨᨨ  �盐矄ᆠ鼀�矄ᨨ鼀盐ᆠ ��� ᆠ�ᆠ盐ᨨᨨᨨ  �盐矄ᆠ鼀 ᆠ ᨨ  矄鼀ᨨᨨ �矄ᨨ    �矄ᨨ  ��� ᨨᨨ  �矄 ᆠ犨

 �ᆠ 矄�矄҈�ᆠ鼀ᔼ ᆠ盐 ᨨ 꾀 ᨨ犨矄 ᨨ盐�  矄鼀ᨨᨨ    盐 � ├ 犨� ���ᨨᨨ�矄 ᲼㝐� ҈桌 ҈҈ ҈҈ 㡰 黨҈맔҈ 犨 㡰 맔҈ 犨 ᆠ㡰 맔҈҈҈犨 㡰 맔҈黨犨

 ��盐矄 ᨨ犨矄ᆠ� 犨�矄�鼀 矄ᨨ�  ᨨ� ᨨ ᨨ鼀ᆠᨨ ᨨᨨ ᨨᨨ�矄ᆠ �  �ᆠ盐 鼀� �ᆠ � �   �ᆠ�ᨨ �ᨨ� �� ᨨ  ᨨ   ��盐 鼀� �盐 ᨨ   � � ᆠ矄矄犨� �鼀I҈  I ᆠ盐 矄�  矄�鼀 矄b ᆠ    ᲼黨桌 d

c

a

҈䰘



b

㡰 I҈>I 㡰 I҈I ᆠ㡰 I҈�矄�   �ᆠ�ᨨ ba I�矄�   �ᆠ�ᨨ cd 㡰 I҈�矄�   �ᆠ�ᨨ ab I�矄�   �ᆠ�ᨨ dc 꾀矄鼀鼀� �矄� � 矄ᨨ犨泐� 矄 犨� ᆠᨨ 矄  ᨨᆠ�泐� 矄� 矄ᨨ ᨨ� 矄 矄 ᨨ犨 �  ��盐␔ �ᆠ � 矄矄 矄 �ᨨ 矄 �犨 鼀 � 盐ᆠ 犨� �鼀 ᲼和桌

2

�鼀

㡰

�鼀

BR A

㡰

AB R

ᆠ㡰 ABR



B A R

Integer Value Answer

҈黨 꾀矄�矄 㜠ᔴᆠᨨ鼀� �ᨨ �矄ᆠᨨ

ᆠ ᨨ 꾀ᔴᨨ� ᨨ  �盐 ⼄盐 ᆠ泐w 㦨� � ⏌矄ᔼ  �鼀  ᆠᨨ   㜠ᔴ ᆠ�ᆠ盐� �矄 R ҈�    �鼀 ᆠᨨ 矄  �

鼀��矄ᆠᨨ 㡰ᨨ  ᆠ�ᆠ盐��矄 ᲼҈҈桌 3

Numeric Answer

 犨ᨨᆠᨨ ᆠ �ᆠᆠ�ᆠ盐ᆠᨨ�矄ᔴ҈ ᔴᆠ �   Ӹ ᔴ҈ 矄�盐 矄  �盐矄ᨨ ҈ᆠ鼀ᔴ 矄 盐 矄  �盐矄ᆠ盐 ᆠ鼀ᔴᆠ�矄�鼀 㜠   ᆠ盐 ᔼ t㡰㦨 �tt졔㡰꾀␔ t�矄� 矄     x 盐ᨨ x�矄힘힘힘힘힘힘 ᲼㝐� 和� ᔼ㡰桌 ҈ 꾀ᆠ�ᆠ盐ᆠᨨ�ᨨ  �盐矄҈ᆠ鼀�矄ᆠ � 盐 � ᨨ鼀鼀� �ᆠ � ᨨ 맔҈� 犨� �矄  �ᆠ盐ᨨ  � � ��泐ᔼ�矄ᨨ ᆠᨨ 矄  �盐矄 ᨨ盐

 �矄 ᨨ �   �鼀 ᨨ  ᆠᨨ�    �ᆠ盐 ᨨ 鼀� �ᆠ � 矄ᨨ �盐 �ᨨ矄  ᨨ ᨨ�ᨨ � 矄

鼀 �鼀盐鼀盐ᨨ 쟼㝐 � 盐ᆠ  � m㡰�  ᆠᨨ�犨� ᆠᨨ矄ᨨ � �힘힘힘힘힘 ᲼㝐� 和 ᔼ㡰桌  ᔼ  盐ᨨ矄ᆠ 鼀ᆠ ᨨ├ 矄鼀 矄 ᨨ鼀㡰҈ᨨ 矄 ᨨ� �矄 ᨨ 盐ᆠ  犨     ᆠ ᨨ├ ᆠ盐  ᆠ  �矄盐 � ᨨ鼀泐 ᨨ鼀�꾀ᨨ�  盐�ᨨ ᨨ � 鼀矄 矄 㜠� 盐ᆠ ᆠᨨ  ᆠ ᨨ├ � 鼀㡰�矄矄�鼀 ᨨ힘힘힘힘힘힘 ᲼㝐� 黨 ᔼ桌

鼀 � 盐ᆠ � ᔴ҈ � 鼀㡰 � 矄 t㦨҈矄�矄

 꾀ᨨᨨ꾀ᔴ쟼 꾀ᨨ 矄��  �矄 矄矄� ᆠᨨ ᨨ� 矄 A 㡰B{�㡰C ��㡰D �㡰E ��㡰 r F �㡰 鼀� �ᆠ � �  �矄��ᨨ �矄 B 㦨 �ˆ 졔 kˆ 㡰 

⼄盐 �泐ᨨ  盐  ᨨ盐�  ᨨᨨABCDEFA � ␔㡰�矄 힘힘힘힘힘힘힘힘힘 . ᲼㝐� 䰘 ᔼ桌 4

㡰

�鼀

҈ 꾀 � ᆠ�ᆠ盐� �ᨨ A�矄   �ᆠ盐ᨨ 盐 � ᨨ鼀鼀� �ᆠ � ᨨ � 盐ᆠ�ᨨ B. A 矄鼀ᆠ盐�矄鼀  �  � � � ᨨ鼀�矄ᆠᨨ

ᆠ ᆠᨨ矄矄   矄矄盐ᆠ   ᨨ矄�矄 ᆠᨨ  ᆠ�ᆠ盐��矄R␔ 

  � � �矄 矄盐  泐矄⼄盐   ᨨ ᨨ   ᆠ � ᨨ犨� � ᨨ盐�  � ᨨ鼀�矄 ᲼҈黨黨�和桌 㡰







�鼀

㡰

Fill in the Blanks

 ᔼ 矄�� ᆠᨨ 盐ᆠ� �犨�ᆠᨨ 矄 ᆠ盐 �矄 ᨨ犨� � ᨨ鼀 ᨨ��  盐ᨨ矄ᨨ盐ᆠᨨ 鼀 ␔   矄ᨨ盐ᆠ �矄矄犨�ᆠ  ᨨ   �ᆠ�ᨨ ᨨ  � 盐ᆠ ᆠ盐 �   犨�犨� ᲼҈黨黨㜠҈㝐├矄桌

WWW.JEEBOOKS.IN

P-221

Electromagnetic Induction

5 �



꾀ᆠᨨ�ᨨ 鼀犨��矄├矄�ᨨ 泐�  ᨨ 㜠盐 � ᨨ鼀 鼀� �ᆠ � 꾀 鼀 �矄� 盐ᆠ �  ᆠᨨ� ᲼҈黨㜠㝐├矄桌 꾀 鼀 ᆠ � 盐ᆠ 犨  犨ᨨ 矄ᨨ 矄��  ᆠᨨ犨�犨  ��矄鼀ᨨ  ᨨ盐� 盐 � ᨨ鼀鼀� �ᆠ �  ᲼҈黨桌 6

䰘

ᆠ㡰 �矄矄盐  泐矄ᨨ �鼀T ᆠ盐 

True / False

MCQs with One or More than One Correct Answer

꾀ᆠ盐 ᆠ泐� �� � �泐ᨨ �犨��矄├ᨨ �  �鼀ᨨ ᆠ�ᆠ盐犨�ᨨᨨ犨� ᨨ盐ᨨ盐ᆠ � ��  ᆠᨨᆠ矄鼀  矄㡰�矄 㡰 ᲼҈桌 㡰 鼀 � 盐ᆠ �  ᨨᨨ�矄 ᨨ�  ᆠ盐 �矄ᆠᨨ 矄  㡰 鼀 � 盐ᆠ �  ᨨᨨ�矄 � ��  ᆠ盐 �矄ᆠᨨ 矄  ᆠ㡰  鼀 � 盐ᆠ �   ᨨᨨ �矄  ᨨ �   ᆠ盐  ᆠ矄矄矄 泐 㡰 鼀 � 盐ᆠ �  ᨨᨨ�矄� � ��  ᆠ盐  ᆠ矄矄矄 泐 10 Subjective Problems



꾀鼀AB ᆠ 矄� ᨨ

犨ᨨ  �ᆠ├ 鼀�ᆠ �矄矄 泐 �矄 ᆠ l  꾀矄�矄 ᆠ R   

� 盐ᆠ ᆠL ᆠᨨ

ᆠ ᨨ �矄矄矄 ᨨ犨 �   ��盐꾀ᨨ �矄�� 犨� ᆠ泐� �ᆠᨨ 矄 ᆠ盐  I�矄ᆠ �   ᨨ  �矄  �ᆠ盐ᨨ 鼀矄矄 ᨨ犨  AB �矄  矄 �矄 ᆠx ᨨ鼀 ᨨ �犨�꾀t㦨 ��矄鼀 ᨨ矄� ᨨ  �矄犨泐 ᨨ鼀 犨�꾀 矄犨   ᨨᨨ犨� �⼄盐矄�ᨨ 矄 ᲼㜠�㝐├矄桌 㡰 � �ᨨ 鼀ᨨ ��

d� df   犨 ��矄  dt dt

� 4

 ᨨ盐� 矄�矄 ᆠR �矄 ᨨ盐 ᨨ 1 �鼀T �  盐ᨨ 

L � 鼀矄ᨨ  ᨨ �� ⼄盐 ��矄 R

黨 꾀ᆠ �盐 鼀ABCD鼀 ᨨ  盐 � ᨨ鼀 鼀 犨� 矄  矄��  ᆠᨨ

ᆠ�ᨨ 犨 E  F 鼀 ᨨ  矄鼀犨�矄矄 ᨨ犨 �  ��AEFD �矄矄⼄盐ᨨ 矄� ҈鼀 EB 㦨FC 㦨 �鼀  �ᆠ�ᆠ盐��矄ᆠ �

矄 �泐� ᆠ矄� �盐 � ᨨ鼀鼀� �ᆠ �  �ᆠ � ᨨ  ᨨ    ᨨ鼀ᨨ�

  ᨨ  ᆠ  �ᨨ   鼀� �ᆠ �  �矄 ҈ ⏌矄  矄�矄 ᆠ盐 � � ᨨ  犨��矄 ҈W ⏌ 鼀  �   鼀� �盐 矄  �ᆠ�ᨨ 矄ᨨ  ᆠ盐 矄�  矄�鼀 矄 AE, BE  EF ᲼҈黨黨㜠�㝐├矄桌  �  �ᆠᆠᨨ矄 ᆠᨨ�矄AB  C ᆠ 犨�  � 矄ᨨᨨ  ᨨ ᔴᨨ�矄A  C ᆠ泐 ⼄盐ᆠ盐 矄矄矄 ᨨ犨 �  ��ᔴᨨ�矄B  C  �  �

ᨨ矄��ᨨ  ᆠᨨ�A�矄鼀ᨨ  ᨨ犨 矄B犨� 盐 � ᨨ鼀 鼀ᨨ�ᨨ ᔼ矄  泐� 盐ᆠ ᆠ盐 �  B 䁸ᔼ  ᨨ �� 矄ᨨ 矄ᔼ 泐矄鼀├  �ᆠ�ᨨ ᨨ  � 盐ᆠ ᆠ盐 �

  ��鼀 ᲼҈黨㜠㝐├矄桌

҈ 꾀ᆠ盐  ᨨ鼀A ᨨB �矄� ᆠ矄� �� 鼀� �盐 ␔ �矄   �ᆠ�ᨨ  ᨨ � 盐ᆠ  ᆠ盐  �  泐 �    ᨨᨨ矄 矄 ᨨ犨 �   ��盐䁸 ᲼҈黨䰘黨桌

ᆠ盐 �  ᆠ�ᆠ盐� f�矄  盐 ᨨ  鼀� �ᆠ �  盐 ᨨ   ᨨ � 犨�  ᨨ盐�    ᆠ�ᆠ盐� 㡰 ᔼ�矄ᨨ矄  �鼀t㦨T 鼀AB �矄  �矄 ᆠᨨ x ᨨ鼀 ᨨ �犨�  矄�矄 ᆠ Rᆠ�矄ᆠ盐 �҈졠�   矄矄�ᨨ  ᨨ   ᆠ �  矄 ᨨ犨  ᨨ盐� 矄�矄 ᆠR ᨨ鼀t㦨 ᨨt㦨T

Topic-2 : Motional and Static EMI and Application of EMI 1 ҈

MCQs with One Correct Answer

꾀 � � �泐ᨨ �矄�� 犨�ᆠ泐� �ᆠ盐 Iᨨ 矄�  ᨨ  ᆠ �盐ᨨᨨ ᆠᨨ 盐ᆠᨨC犨� 矄� � � ᆠᨨ

ᆠᨨᨨᆠ �  矄鼀 矄矄 ᨨ犨 �   ��盐 ᆠᨨ

ᆠᨨ 矄 �  l  矄�矄 ᆠ R ᔼ

矄� 矄ᨨ �� 犨� ᨨᆠ�泐v 矄�矄 ᆠᨨ   ᆠᨨ 盐ᆠᨨ     矄  � 盐ᆠ ᆠ ᨨ    ᨨᨨ 

���� � 盐ᆠ ᆠ盐 �  ᨨᨨ矄 盐 ᆠ�ᨨ

ᨨ 矄�ᨨ  r 犨   ᆠᨨ

ᆠᨨ   矄��  犨��矄 ᲼㝐� 和� ᔼᔼ㡰桌

WWW.JEEBOOKS.IN

EBD_8341 P-222

Physics

ᨨ 矄� ᨨ  ᨨ � ᆠᨨ 盐ᆠ� �犨�ᨨᨨ

C I

鼀� �ᆠ �  ᨨ ҈  ᔼ   矄� �矄盐  ᨨ鼀 �矄 ⼄盐���盐鼀 ᨨ矄��ᨨ    矄    盐鼀 ᨨ ᨨ矄ᆠ��ᨨ 矄� ᨨ鼀矄 ᨨ�矄鼀�盐  ᆠ矄矄泐  ᆠᨨᨨ e�矄ᔼ  鼀矄矄ᨨ 矄��矄��鼀矄 �矄 矄�矄 ᆠ҈W � � ����犨�ᆠᨨ矄ᨨ ᲼㝐� 꾀�҈黨ᔼ桌

R

v

l

r

m  Ivl m Ivl m  Ivl m Ivl 㡰 ᆠ㡰 㡰 p Rr p Rr p Rr p Rr 꾀��  �矄ᆠ鼀 ᨨ 盐鼀� �盐鼀  ᨨ 鼀� �ᆠ鼀�㡰�矄 ├ ᨨ� ᨨ 泐 �矄 ᨨᨨᨨ盐�矄  �矄 矄 矄 ᨨ犨 �   ��盐꾀矄ᨨ �鼀� �矄  �ᆠ泐 ᨨ� ᨨ  �矄ᆠ犨泐 ᨨ鼀�矄 �矄졠 ᨨ� �  鼀� ᨨ盐  �矄ᨨ   �矄ᆠ  �矄ᆠ犨� ��盐�矄 矄ᆠ 鼀�ᆠ  ᨨ 犨 ᨨ矄ᆠ㡰 ᲼꾀 桌

㡰 



䰘

和 



㡰 ᨨ �    �ᆠ�ᨨ  ᨨᨨ矄� ᨨ  �ᆠ�ᨨ  ᨨ 鼀� 矄鼀ᨨ�ᨨ

㡰 ᨨ�  矄鼀 �ᆠ�ᨨ 矄  �ᆠ�ᨨ ᨨ 鼀� 矄 鼀ᨨ�ᨨ

ᆠ㡰 ᨨᨨ �矄鼀盐犨�鼀� 盐 ᆠ  � 㡰 ᨨᨨ盐�矄鼀盐犨�矄ᨨ犨泐�矄

 ��盐矄 ᨨ犨矄矄⼄盐ᨨᨨᨨ 矄� �ᆠ鼀犨 �ᆠ �矄 ᆠᨨ

ᆠ ᨨ 犨ᨨ├ᨨ 矄�矄 ᆠ矄 犨 ᨨ矄盐 �矄鼀ᨨ� �ᨨ犨 矄�� 犨� ᆠᨨ 矄 矄 ᨨ ҈ᆠ鼀矄  ҈ 꾀矄ᨨ鼀� 矄 ᨨ �矄� 盐 � ᨨ鼀鼀� �ᆠ � ᨨ  ҈   �ᆠ盐 ᨨ     ᨨ    ᨨᨨ ᔼ    矄�矄 ᆠᨨ �矄҈䰘! ᆠ盐 �  ᨨᨨ  � 矄 犨�ᆠᨨ矄ᨨ ᲼㝐� ҈꾀҈黨ᔼ桌





�

㡰 ᆠ矄矄泐 ᆠᨨᨨ  黨  꾀  � 矄盐� � � ᨨ  ᨨ  �  l 矄�  ᆠ � x  矄�泐r x㡰㦨 r ᨨ � ᨨ �矄ᨨ ᨨ盐

l  �矄矄矄� � ᨨ盐�  ᨨ���  x㦨㡰  �ᆠ盐 ᨨ ᨨ ᔼ  ᨨ 鼀├矄 ᨨ�ᨨ 矄矄ᆠᨨ  

 �鼀� 鼀� �ᆠ鼀ᨨ鼀 ᨨ  ᨨ �矄 ᲼㝐�  ҈   ҈黨 ᔼ桌 p p

r l  ᆠ㡰

r l  㡰 r l   꾀ᆠᨨᨨ ᨨ 鼀矄矄鼀矄� 矄盐 ��泐ᨨ 犨ᨨ矄鼀ᨨᨨ �矄犨� 矄�ᨨ ҈ 矄  �ᨨ q 犨�   ᨨ� ᨨ 꾀 ᨨᨨ鼀�矄ᨨ�  泐 矄�矄 ᆠ  �矄盐 � ᨨ鼀鼀� �ᆠ �  ᨨ鼀ᨨ   ᨨ  �矄矄矄 ᨨ犨 �   ��盐 鼀�  矄 ᨨ  ᆠᨨᨨ �矄 ᲼㝐� 졠 � 꾀�҈�҈桌

㡰 p r l

黨

㡰 Ҙ꾀 㡰 ҈䰘Ҙ꾀 ᆠ㡰 ҈�Ҙ꾀 㡰 ҈҈�Ҙ꾀

 ᨨ 盐鼀 ᨨ 盐 矄   ᆠᨨ矄矄㜠矄ᆠ�ᨨ   �   矄ᨨ ᨨ� �矄 �  ᨨ犨�矄 � �矄� 泐 盐矄� �   矄�ᨨ  犨  犨� � �矄  � 盐ᆠ ᆠ ᨨ 矄ᨨ ᨨ� 犨�ᨨᨨ�ᨨ ᨨ ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰  㡰  ᆠ㡰 ҈⏌ 㡰 ҈⏌ 꾀 � 矄�҈ᆠ鼀ᨨ ��矄ᨨ 矄  犨�ᨨ  ���� 矄�矄 ᆠ ��矄ᆠᨨ

ᆠ ᨨ矄� �ᨨ 矄� �ᆠᨨ 矄  �鼀҈ 矄 ��盐㡰 矄矄鼀泐�矄├� 盐 � ᨨ鼀

㡰 ҈ 㡰 � ᆠ㡰 � 㡰 ҈ 꾀҈鼀ᨨ � ᨨ� ᨨ 犨�  矄 ᨨ鼀ᨨ 쟼矄ᨨ 和ᨨ盐 ␔矄ᔼ�矄 � �犨� 矄 ᨨ �鼀矄҈��   �矄ᨨ  ᨨ� ᨨ ᆠᨨ鼀ᨨ  ᨨ   矄鼀� �ᆠ � ᨨ 맔҈␔⏌鼀 盐ᨨ  � 盐ᆠ 鼀 �

犨��矄 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 ҈�맔҈ 㡰 ҈҈맔҈ ᆠ㡰 �맔҈ 㡰 맔҈ 꾀ᆠᨨ犨��矄犨ᨨ盐 ᨨ 犨ᨨᨨ   鼀犨 ᨨ矄矄  �矄 ᨨ  ⼄盐�� �ᔼ  �  �鼀 矄�ᨨ ᨨ ᆠ 矄� ᨨ   鼀�矄� ᆠ矄 泐 ᆠᨨᨨ ├� �   盐鼀ᨨ 盐 矄ᨨ  ᆠᨨ�盐 � � ᨨ   鼀  矄鼀   矄 � 盐ᆠ ᆠᨨ  ᆠᨨ� ᲼㝐� ҈҈ ҈黨ᔼᔼ桌 㡰 ᆠ矄矄泐 ᆠᨨᨨ 黨 㡰 � ᆠ矄矄泐 ᆠᨨᨨ 䰘 ᆠ㡰 � ᆠ矄矄泐 ᆠᨨᨨ 

㡰

®

B

l R

㡰 ᆠ㡰

鼀� ᆠᨨ矄 q  

 l 鼀�  q l 

q

㡰 㡰

鼀� 矄� q l  鼀� ᆠᨨ q l 

WWW.JEEBOOKS.IN

P-223

Electromagnetic Induction

꾀矄⼄盐 鼀ᨨ 矄� ҈ᆠ鼀 ᨨ �矄�� 犨� ᆠ泐� �ᆠ盐 ҈꾀�  ᨨ  和� � ᨨ鼀ᆠᨨ矄ᨨ 犨�  鼀鼀ᨨ矄ᨨ犨 矄 ��  犨� ᆠᨨ 矄 矄 ᨨ ҈鼀矄҈ 矄 ��盐㡰᲼꾀 桌

҈

ᔼ㦨҈꾀



҈ᆠ鼀

鼀 � 盐ᆠ  �鼀  鼀ᨨ   鼀�矄 㦨҈ᆠ鼀 ᨨ鼀 犨��矄 ᲼졠 � 꾀�҈黨҈桌 ᆠ㡰 䰘�m 㡰 �m 㡰 m 㡰 ҈m 꾀鼀�ᆠᨨ ᨨ  � �l�矄� ᨨ矄� �ᨨ  � l  鼀 ᨨᨨ犨�  �盐矄 wᨨ  ᨨ� ᨨ  犨� ᨨ  ᨨ  矄� � �  ᔼ  �矄�ᆠ 鼀� �ᆠ � ��  ��ᨨ  鼀 � 盐ᆠ ᆠᨨ矄矄   矄ᨨ  ᨨ �矄 ᲼҈桌

҈҈

㡰

 Bwl 

㡰

Bwl  ᆠ㡰 

 Bwl  㡰 

�Bwl  

犨ᨨ ᆠ�ᆠ盐 ᆠᨨ�矄 ᆠ   � �  泐 ᨨ     矄�盐�ᨨ 矄矄 ᨨ犨 �   ��盐 �鼀盐盐� 盐ᆠ ᆠ 犨� ᲼҈和桌

҈



㡰

҈

㡰

ᆠ㡰

㡰 鼀 �鼀盐鼀� 矄�盐�ᨨ  㡰 㡰 鼀 �鼀盐鼀� 矄�盐�ᨨ  㡰 ᆠ㡰 鼀 �鼀盐鼀� 矄�盐�ᨨ  ᆠ㡰 㡰  矄鼀� 矄�盐�ᨨ 矄 꾀鼀�ᆠ矄⼄盐ᨨᨨABCD �矄鼀ᨨ� �� �矄ᨨ犨   犨� ᨨᆠ�泐v � 盐 � ᨨ鼀鼀� �ᆠ �  �ᆠ盐 ᨨ�矄 矄矄 ᨨ犨 �    ��盐꾀 ᆠ�ᆠ � �矄 � 盐ᆠ ᲼҈和桌 꾀

 



ᔴ

㡰 � AD盐 ᨨ� BC 㡰 � BC盐 ᨨ� AD ᆠ㡰 � � AD ᨨ� BC 㡰 � ᨨ AD  BC

҈ 꾀 ᆠᨨ� ᨨ � 盐ᆠ ᆠ  鼀  矄�矄 ᆠ   W  �矄 ᆠᨨ

ᆠ ᨨ҈泐 ᆠ盐 �  ᆠᨨ��矄҈꾀 ᨨ �鼀泐 �鼀 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 �矄 㡰 �矄 ᆠ㡰 �鼀矄 㡰 ҈鼀矄 ҈� 꾀  �  矄鼀�㜠ᆠ�ᆠ盐 ᆠᨨ 盐ᆠ� � � �ᨨ  �盐矄 �矄 � �犨� �矄  �ᆠ�  ᨨ� ᨨ 鼀� �ᆠ ur � 盐ᆠ�ᨨ  B 꾀 ᨨ矄��ᨨ MNQ  矄 ᨨ  � ��矄v   ᨨ � �  ᆠ ᨨ ᆠᨨ矄矄 � ��矄 㡰 ᨨ ᲼҈黨黨㜠㝐├矄桌  㡰 BvpR ⏌ M �矄 �� ᨨ � ᆠ㡰 pRBv Q �矄 �� ᨨ � 㡰 RBv Q �矄 �� ᨨ � ҈ 꾀鼀ᨨ 鼀ᨨ矄ᆠᨨ 矄 ᨨᆠ�泐�  �ᆠ�ᨨ

 �ᆠ盐ᨨ�矄 � 꾀ᆠᨨ 矄 盐 � ᨨ鼀鼀� �ᆠ �  �矄矄� 矄ᆠ�  �ᆠ�ᨨ  �ᆠ盐ᨨ ᨨ 矄犨矄�矄ᨨᆠ�泐和ᆠ ᆠᨨᆠ矄鼀  ᨨ鼀   ᨨᨨ犨� � ᲼҈黨黨和㜠㝐├矄桌 㡰  �ᨨ �矄 矄鼀ᆠ�ᆠᨨ � 㡰 �矄 ᆠ�ᆠ � �  ᨨ  ᆠ㡰 ᆠ�ᆠᨨ ��矄 �� 矄 ᆠ ᨨ   ᨨ   ᆠ矄矄ᨨ犨 矄�矄 矄 㡰 ᆠ�ᆠᨨ ��矄ᨨ犨矄  ᆠ ᨨ   ᨨ  � ᆠ矄矄ᨨ犨 矄�矄 矄 ҈䰘 꾀矄鼀矄⼄盐ᨨᨨᨨ 犨�ᨨ 矄� l�矄ᆠ � 矄� � 矄⼄盐ᨨᨨ ᨨ 犨� ᨨ 矄�  L >>l㡰  ᨨᨨ矄 ᆠᨨ㜠    �ᆠ 矄ᆠᨨ� ᆠ�  鼀盐盐� 盐ᆠ ᆠ ᨨ  矄泐矄鼀�矄ᨨᨨ�ᨨ ᨨ ᲼҈黨黨和㜠㝐├矄桌 㡰 l⏌L 㡰 l⏌L ᆠ㡰 L⏌l 㡰 L⏌l ҈ 꾀ᆠᨨ 盐ᆠ� �矄⼄盐ᨨᨨᨨ 矄� L  矄�矄 ᆠR 鼀ᨨ矄� �矄  犨�   盐 � ᨨ鼀 ᨨᆠ�泐 v  �ᆠ盐ᨨᨨ ᨨ �矄矄� 矄꾀 鼀� �ᆠ� 盐ᆠ�ᨨ Bᆠᨨ 矄 �

�鼀 矄ᆠᨨ� � � �ᆠ盐  � ᨨ  ᨨ  ᨨᨨ �矄矄泐犨 

ᆠ盐 � 盐ᆠ �  ᨨᨨ�矄 ᲼҈黨黨㜠㝐├矄桌 㡰 BLv/R ᆠᨨᆠ├犨�矄 㡰 BLv/R �ᆠᨨᆠ├犨�矄 ᆠ㡰 BLv/R  �ᆠᨨᆠ├犨�矄 㡰 ᨨ 4

Fill in the Blanks

҈黨 꾀 盐 � ᨨ鼀泐犨ᨨ盐  矄ᨨ ᨨ�  ᆠᨨ� ᨨ 矄  � 盐ᆠ ᆠ ҈맔҈  泐 矄�矄 ᆠᨨ 鼀�矄ᨨ├ 盐� ᨨ 犨ᨨ�  �ᆠᆠᨨ�矄 矄�  �ᆠᆠᨨ�矄  ᆠᨨ

ᆠ � ᆠᨨ矄矄҈�㜠ᨨ泐ᨨ  ����矄�矄 ᆠ

�鼀ᆠᨨ 矄  ᨨ ᆠ盐 �  ᆠ�ᆠ盐��矄 矄ᆠᨨ 矄  矄 泐矄ᆠ盐  ᨨ盐�  泐 �矄鼀矄 ᲼҈黨黨㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-224

Physics

5 

True / False

꾀ᆠᨨ 盐ᆠ� �ᨨ AB 鼀ᨨ矄ᨨ  㜠 �矄 矄 ��㡰 �   盐 � ᨨ鼀 鼀� �ᆠ �  ᨨ� � � �    ᨨ矄�� 㜠 �ᆠ�ᨨ   A ᨨ  ᨨ �矄ᨨ矄��泐ᆠ �  ᲼҈黨䰘㜠㝐├矄桌

 盐泐ᆠᨨ矄矄矄 ��ᨨ   ᨨᆠ�ᨨ ᨨ   ��  �ᨨ  ᨨᨨ 㡰ᔼ 㡰  㡰矄   ᨨᆠ�泐ᨨ  ᨨᨨᆠ盐 �  ᨨᨨ  ᨨᆠᨨ   ᨨᨨ矄ᆠ�泐矄 盐 ᆠ�ᨨ ᨨ  ᔴᨨ盐 㜠ᆠᨨᆠ├犨�矄 ᆠ盐 �矄├ 矄ᨨ矄�� ᲼꾀 ҈桌

y Ӹ 

B 

v



A











␔ �ᆠ ᨨ   ᨨᨨ犨� �矄ᆠ 鼀�ᆠᨨ 矄㡰�矄 㡰ᆠᨨᆠ䁸 ᔼ� ᨨ��泐㡰



ᔼ 㡰

x  㡰

6 ҈

MCQs with One or More than One Correct Answer

꾀ᆠᨨ 盐ᆠ� �犨�ᨨ ᨨ�ᆠ矄 � ��泐y㦨x�矄鼀ᨨ� � ur 犨�  ᨨᆠ�泐 V = V $� �  ᨨ 盐 � ᨨ鼀鼀� �ᆠ �





㡰 

























æ æ y öb ö ur B = B ç҈ + ç ÷ ÷ k$ 矄矄 ᨨ犨 �  ��盐ᔼ VBL b ç è Lø ÷ è ø

ᨨ矄��ᆠᨨ 矄 矄  Df �矄 ᨨ � �  ᆠ ᨨ 犨   矄ᨨ  犨�   ᆠᨨᆠ 矄鼀  矄㡰�矄⏌ ᲼꾀 ҈黨桌

㡰

ᔼ 㡰

ᆠ㡰

㡰 



















y

 꾀ᆠᨨ 盐ᆠ� �ᨨᨨ�  矄 ᨨ ��  � �矄ᨨ矄ᆠ矄 � �ᨨ  �� ҈ᆠ鼀�矄├矄盐ᆠ   黨  �矄 泐ᆠᨨ矄ᨨ � � �泐ᨨ �ᆠᨨ 盐ᆠ� �犨� 矄  ��盐㡰 犨��矄ᆠ�ᆠ泐� 矄盐  ᨨ鼀 ᨨᨨ  泐ᨨ 盐矄ᨨ  � ��矄ᨨ 犨� ᆠ盐  �  � �盐ᨨᨨ�矄� ᆠᨨ盐 ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  � ᆠ矄    ᆠᨨ 矄   ᨨ  ҈꾀矄҈ ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌

B

L 

V = V� 

L

x

㡰 Df �矄ᨨᨨ�ᨨ ᨨ  � ᨨ  犨�ᨨᆠ ᨨ  泐㜠 �矄 㡰 Df 鼀� 矄 矄鼀�  ᨨ�ᆠ犨��矄ᆠ



泐矄�� 犨�y㦨x� ��泐ᨨ  �  L ҈ ᆠ㡰 Df = BV L  ᨨb㦨   㡰 Df 㦨 BV L  ᨨb㦨  꾀��� 犨�ᨨᨨᨨ 矄⼄盐矄  � �矄� ᨨ  �   矄�矄 ᆠ �矄鼀ᨨ� �ᨨ �  㜠 �矄犨� ᆠᨨ 矄  ᨨᆠ�泐�   ᨨ  꾀㦨 ��   �ᨨ  ᨨᨨ 矄��ᨨ ᨨ  � 犨   �矄盐 � ᨨ鼀鼀� �ᆠ � � ᨨ  ᨨ   矄矄 ᨨ犨 �   ��盐 ᨨ矄盐 �ᆠ� 泐� ᨨᨨ

҈ᆠ鼀

黨

æ m ö 㡰 鼀� �盐 ᨨ � 盐ᆠ emf�  犨��矄 çè ÷ø ᨨ p 㡰 ᔼ  ᨨᨨ�矄ᨨ ᆠᨨ 矄  �盐矄 ᨨ盐 æ m ö  犨�  ��ᨨ emfᨨ  çè ÷ø ᨨ�矄� 盐ᆠ �

p  犨� ᆠ㡰 � 盐ᆠ ᆠ盐 �  犨��矄� ᨨᨨ矄� �ᆠ�ᨨ

ᨨ ᆠ盐 ᨨ �  泐ᨨ 盐矄 㡰 �矄盐矄� ᨨᆠ犨  犨�  ᨨᨨ  SI 盐 �ᨨ � 盐ᆠ ᆠ   泐ᆠ 犨� 矄 ᲼҈黨黨和㜠㝐├矄桌 㡰 犨⏌鼀 㡰 ᨨ㜠矄ᆠᨨ ⏌鼀 ᆠ㡰 ᨨ盐⏌ 鼀㡰 㡰 ᨨ 鼀㜠矄ᆠᨨ

WWW.JEEBOOKS.IN

P-225

Electromagnetic Induction

�

犨ᨨ �  ᆠᨨ�矄 矄 㜠� 盐ᆠ ᆠ矄 L҈ =  鼀 L㦨鼀 ᆠ盐 � ᨨ ᆠᨨ��矄� ᆠ矄 ᆠᨨ 矄   ᆠ盐 �  矄ᆠᨨ ᆠᨨ��矄矄ᨨ� ᆠ矄   矄鼀ᆠᨨ 矄 꾀ᆠ� � 矄 ᨨ �鼀 ᨨ犨 �� ᨨ 犨ᨨᆠᨨ�矄�矄 矄鼀꾀 �鼀 ᆠ盐   � 盐ᆠ ᨨ�   �泐矄ᨨ �   �矄ᆠᨨ� �҈V҈ W҈矄ᆠ�泐ᔴᨨ矄ᨨ � �盐矄 ᨨ   矄ᆠᨨ  ᆠᨨ�    矄鼀 � 矄   � V   W 矄ᆠ�泐   ᲼҈黨黨㜠㝐├矄桌 �҈ ҈ 㡰 � =  

㡰

�҈ = �

ᆠ㡰

W҈ ҈ = W  㡰

V҈ = V

 꾀鼀ᨨ OA ᨨ 鼀矄矄�m  � �r�矄├ᨨ� � 犨� ᆠᨨ 矄  �盐矄  w � �ᆠ ᨨ盐 ᨨ� ᨨ  �矄  O   A�矄 � ᨨ 矄� 犨� ᨨ盐 �ᆠ�ᨨ ᨨ � �  ᆠᨨ 盐ᆠ� �ᆠ�ᆠ盐� � �  矄鼀 矄 ᨨ ᨨ�ᨨ 꾀盐 � ᨨ鼀 ᆠᨨ 矄  r 鼀� �ᆠ� 盐ᆠ�ᨨ  B �矄�  �ᆠ盐 � ᨨ   ᨨ ᨨ�ᨨ 矄矄 ᨨ犨 �   ��盐ᨨ犨꾀 � 盐ᆠᨨ       矄�矄 ᆠR ᆠᨨ

ᆠ  ᨨ盐�   矄犨�ᆠ S 犨  ᨨ� O  ᨨ� C ᨨ  � �ᨨ ᨨ鼀 ᆠ�ᆠᆠ�ᆠ盐��ᆠ 矄�矄 ᆠᨨ  � �   ᨨ ᔼ ��泐 矄犨�ᆠ �矄ᨨ  ᲼҈黨黨�㜠҈㝐├矄桌

10 Subjective Problems 

䰘

꾀鼀� �ᆠ � B㦨B y⏌a㡰 kˆ �矄� ᨨ �   졔z �ᆠ�ᨨ B ᨨ矄��ᆠᨨ 矄 矄꾀矄⼄盐ᨨᨨ EFGH ᨨ 矄� 鼀矄矄m 矄�矄 ᆠR� x y   矄矄 � �盐  � 盐 ᆠᨨ ��泐矄 ��盐㡰ᨨ   �ᆠ�ᨨ 矄ᨨ x  y  矄�  ��盐 ᲼҈黨黨黨㜠҈㝐├矄桌

� 㡰  � 盐ᆠ ᆠ盐 �  ᨨᨨ � �ᆠ�矄 �ᆠ�ᨨ  㡰  ᨨᨨ   ᨨᆠᆠ� �ᨨ  ᨨᨨ � �ᆠ �矄 �ᆠ�ᨨ  ᆠ㡰   矄矄�ᨨ  ᨨ 矄 ᨨ  ᨨᨨ v t㡰 �矄 鼀� 盐 꾀�ᨨ  ᨨ� ᨨ ᆠᨨ 盐ᆠ� ��矄ᨨ  ���� 矄�矄 ᆠ 矄 ᨨ   ᨨ    �矄 �   ᨨ     �矄 ᆠ犨  �矄�矄L꾀ᆠᨨ 盐ᆠ� �鼀矄矄矄矄ᨨ ᨨ 矄�矄 ᆠRᆠ 矄� ᨨ  �矄 �ᆠ�ᨨ 矄矄泐 ᨨ �矄�  ᨨ 鼀矄矄矄矄矄� � 犨 �ᆠ  矄矄矄ᨨ  盐泐 �  ᨨ  �ᨨ  꾀鼀矄矄m� ᨨ ᨨ   ᨨ  矄� �  �矄�ᆠ泐꾀ᆠᨨ 矄 鼀� �ᆠ � B  �矄矄 �ᆠ盐ᨨ ᔼ  矄泐矄鼀�矄 矄  ᨨ鼀矄ᆠᆠ盐 ᲼҈黨黨䰘㜠�㝐├矄桌

�㡰  鼀� ᨨᆠ�泐ᆠ � 泐 ᨨ  ��㡰  ᆠᆠ�ᨨ ᨨ  鼀矄矄 � 矄 犨    ᨨᆠ�泐ᨨ  ᨨ �矄   鼀� ᨨᆠ�泐

㡰 ␔ �矄 � 盐ᆠ 鼀 ᆠᨨ矄矄 鼀� 矄ᨨ   矄犨�ᆠ 䁸 㡰 矄犨�ᆠ S �矄ᆠᨨ矄 �鼀t㦨 �㡰 졠�   矄矄�ᨨ  ᨨ ᆠ盐 矄 盐 ᆠ�ᨨ

ᨨ �鼀 ��㡰 ᔼ  矄 泐矄ᨨ�  �鼀   ᆠ ᨨ  ᨨ⼄盐⼄盐� ᨨ鼀� �  ᆠᨨ 矄   �盐矄 ��   ᨨ OA 犨矄ᨨ �  ᨨ矄��㜠 �矄t㦨 R҈ 黨 犨ᨨ�ᆠ鼀�ᆠ�矄AB  A C  CD 矄 泐҈鼀 泐 L  ᆠᨨ

ᆠ   犨ᨨ  矄 泐 矄�矄 ᆠ矄R҈   R 矄 矄 ᨨ犨 �

��盐꾀 ᨨ� ᨨ 鼀�ᆠL ᨨ 鼀矄矄├�矄� 矄犨� ᨨ盐 �ᆠ�ᨨ

R �ᆠ泐 ᨨ犨   �矄盐   D ᆠ�ᨨ ᨨ ��泐 �矄盐 � ᨨ鼀 B ᨨ� ᨨ 鼀� �ᆠ � ᨨ  矄  �ᆠ盐ᨨ  ᨨ  �矄ᔼ�矄ᨨ矄   犨     鼀�  ᨨᆠ�泐 �矄 �     ᨨ犨矄 �矄矄�  �  R ҈    R    䰘 ␔   ҈ 犨 矄ᆠ�泐 �  鼀� ᨨᆠ�泐ᨨ  L   盐矄ᨨ R҈ R ᲼҈黨黨㜠㝐├矄桌  和ᆠ�矄 ��  泐 � AD � ᨨ犨ᨨ��ᨨ 矄 ��ᨨ

ᔼ�矄 �     ��ᨨ ᔼᔼ 矄盐 � ᨨ鼀鼀� �ᆠ � B �ᆠ � ᨨ   ᨨ    ACD �矄  矄鼀�ᆠ�ᆠ盐ᆠᨨ 盐ᆠ� �ᨨᨨᨨ  �盐矄r犨� ᆠ O   ᨨ  ᨨᨨ� ��   ᨨ    ᨨᨨ�矄 ᨨ犨鼀 ᨨᨨ犨� ᆠᨨ 矄  �盐ᨨᆠ�泐 wᨨ盐  �矄矄矄� � ᨨ盐� O   �ᆠ盐 ᨨ  ᨨ    ᆠ�矄�矄 ᆠᨨ   ᨨᨨ�矄R ᲼҈黨�㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-226

҈

Physics

�㡰 졠�   矄矄�ᨨ  ᨨ 鼀� �盐 ᨨ  � 盐ᆠ ᆠ盐 �  ᨨᨨ ��㡰 和 ᨨ犨  �ᆠ�ᨨ ᨨ  ᆠ盐 犨   ᨨᨨ�矄  � �� ᨨ  ��ᨨ ᔼᔼ ���㡰 ᨨ� 犨  � 盐ᆠ 鼀   �鼀 ᨨ ᨨ�ᨨ  ᨨ犨ᨨ�ᨨ 矄ᨨ ᨨ�ᨨ  꾀矄⼄盐鼀犨�ᨨᨨᨨ 矄� ҈ᆠ鼀矄 矄�矄 ᆠ҈ ᨨ 鼀�矄鼀ᨨ 犨� ᆠᨨ 矄 ᨨᆠ�泐v0 �   盐 � ᨨ鼀 鼀� �ᆠ � ᨨ � 盐ᆠ�ᨨ B㦨犨矄⏌鼀矄矄 ᨨ犨 �

  ��盐 鼀� �ᆠ � � 矄 �ᆠ盐ᨨ

  ᨨ  ᨨᨨ �ᆠ  � ᨨ   㡰  ᨨᨨ �矄 ᆠᨨ

ᆠ ᨨ 犨ᨨ├ ᨨ   矄�矄ᨨ矄 ᆠ  ᨨ 盐  ᨨ 鼀矄   矄�矄 ᆠ矄ᨨ   犨�矄OS  PQ  ����␔ 矄 ᨨ盐  矄 ᨨ  ᨨᨨ矄ᨨ矄ᨨ 矄 泐ᆠ盐 ᨨ ҈鼀��鼀�

 ᨨᨨ䁸෌�  �ᆠ�ᨨ ᨨ ᆠ盐 �  ᨨᨨ ᲼҈黨㜠㝐├矄桌  犨ᨨ�矄ᨨ �犨泐ᆠ├� 矄盐  ᨨ鼀ᆠ ᨨ    �ᨨ盐 ᆠᨨ

ᆠ ᨨ鼀��ᨨ鼀␔ �矄   � �ᨨ  鼀��ᨨ鼀犨  � 矄 矄 ᨨ ҈├鼀⏌ ᨨ盐ᨨ � ᆠ├��   �ᆠ ᆠᨨ鼀ᨨ  ᨨ  矄鼀� �ᆠ � �矄맔҈犨⏌鼀  �矄矄 泐҈鼀䁸  ᲼҈黨҈㜠㝐├矄桌

Topic-3 : Miscellaneous (Mixed Concepts) Problems 1 ҈





MCQs with One Correct Answer

꾀 � � �泐ᨨ �ᆠ泐� �矄├ᨨ 盐 � ᨨ鼀 鼀� �ᆠ � B �ᆠ ᨨ �ᨨ矄�� 㜠 �矄  �ᆠ�ᨨ ᨨ � 盐ᆠ ᆠ盐 矄矄  ᨨ鼀  㜠 �矄犨�  ᲼�和桌 㡰 ᨨ 㡰  �ᆠᨨᆠ├犨�矄ᨨ  졔  �矄 ᆠ㡰 ᆠᨨᆠ├犨�矄ᨨ  졔  �矄 㡰 ᨨ � 鼀� �ᆠ � 꾀矄 ᨨ㜠ᆠ�ᆠ盐� ᆠᨨ��矄ᆠ � �鼀㜠泐� �鼀� �ᆠ �  쟼ᆠ�ᆠ ᨨ犨 �矄 �矄矄�  盐ᨨ  ᆠ盐  � 盐ᆠ  �    ᆠᨨ� ᔼ   盐鼀 ᨨ 盐 矄 犨ᨨ ⼄盐 盐   犨� �盐矄   ᆠ�ᆠᨨ犨 �矄矄� 犨ᨨ盐  ᲼和桌 㡰  㡰  矄鼀 ᆠ㡰 ᨨ盐 㡰 ⼄盐 盐 꾀矄矄 ᨨ犨 �   ��盐P  Q 犨ᨨᆠᨨ �ᆠᨨ 盐ᆠ� � ᨨᨨ矄矄 泐矄ᨨ鼀 �矄 ᆠ␔   矄犨�ᆠ S�矄 ᆠᨨ矄 ᆠᨨᆠ├犨�矄ᆠ盐 IP ᨨ犨矄� P 矄矄 泐E㡰   � 盐ᆠ ᆠ盐 IQ1 ᨨ犨矄� Q 矄犨�ᆠ 鼀� 矄 ᆠᨨ矄  ᨨᨨ ��鼀␔  S�矄ᨨ  ᆠ盐 IQ ᨨ犨矄� Q    �ᆠ�ᨨ IQ҈ IQ 矄矄 泐E㡰  ᲼和桌



�

㡰 矄ᆠ�泐ᆠᨨᆠ├犨�矄  �㜠ᆠᨨᆠ├犨�矄 㡰 ᨨ ᆠᨨᆠ├犨�矄 ᆠ㡰 ᨨ  �㜠ᆠᨨᆠ├犨�矄 㡰 矄ᆠ�泐 �㜠ᆠᨨᆠ├犨�矄 ᆠᨨᆠ├犨�矄 꾀 ᆠᨨ� ᨨ 犨� � � � 盐ᆠ ᆠ   矄�矄 ᆠ 矄  ᆠᨨ 盐ᆠ� �� � ᆠ ᆠᨨ �泐犨� �  �  ᆠᨨ� �矄 ᆠᨨ

ᆠ ᨨ泐�鼀t㦨矄ᨨ �鼀㜠    ᆠ盐 ҈ t㡰矄矄 ᨨ犨� � ᨨ盐�  ᆠᨨ�ᔼ I t㡰�矄  ᆠ盐 � 盐ᆠ �  � � B t㡰�矄 鼀� �ᆠ �    �矄ᨨ  ᆠᨨ� 盐ᨨI҈ t㡰  矄 盐 ᆠ�ᨨ ᨨ �鼀 t>㡰 ᨨ 盐ᆠI t㡰B t㡰 ᲼和桌 㡰 � ᆠ矄矄犨� �鼀 㡰 ᆠ矄矄犨� �鼀 ᆠ㡰 ᨨ矄 ᨨ泐犨� �鼀 㡰 矄矄矄 ᨨ盐� 鼀 �鼀盐鼀 꾀盐 � ᨨ鼀盐�鼀㜠泐� �鼀� �ᆠ � B t㡰 �矄矄�  ᆠ�ᆠ盐��ᨨ ᨨ  �盐矄 �矄 �ᆠ � ᨨ  ᨨ  矄矄 ᨨ犨  鼀� �盐 ᨨ  � 盐ᆠ ᆠ�ᆠ � ᨨ�  �矄 ᆠ ᨨ鼀 ᆠ ᨨ  ᆠ�ᆠ盐 ��ᨨ

᲼和桌 㡰 �矄 ᨨ 㡰 ᆠ矄矄矄҈⏌r ᆠ㡰 � ᆠ矄矄矄r 㡰 ᆠ矄矄矄҈⏌r



犨ᨨ�  �ᆠᆠ�ᆠ盐ᨨᨨ矄ᨨ 鼀犨�泐� �ᨨ  犨� ᨨ盐ᨨ盐ᆠ � �ᆠ ᨨ ᨨᨨ㜠꾀ᆠ�矄ᆠ盐  犨 �ᆠ � ᆠ矄矄犨� �鼀ᔼ 矄ᨨ 矄 ᨨᨨ㜠 㡰 鼀� 矄矄�ᨨ 泐 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 �矄ᆠ 泐 ᨨᨨ㜠꾀 ᆠ㡰 �矄 泐 ᨨᨨ㜠꾀 㡰 ᨨ矄ᨨ盐�矄ᔴ㝐犨� ᔴ㝐 � 

WWW.JEEBOOKS.IN

P-227

Electromagnetic Induction

6 䰘

MCQs with One or More than One Correct Answer

꾀矄ᨨ盐ᆠᨨ ᆠᨨ 矄 ᨨ��矄ᆠᨨ

ᆠ ᨨ矄�矄 ᆠ  犨ᨨ� � 盐ᆠᨨ矄҈  ᨨ盐� 矄犨�ᆠ 和矄 矄 ᨨ犨  �矄 ᨨ鼀盐盐� 盐ᆠ ᆠ犨  犨ᨨ � 盐ᆠᨨ矄 矄犨�ᆠ 和�矄� ��泐ᨨ 꾀㦨 矄犨�ᆠ �矄ᆠᨨ矄  ᆠ盐 �� 矄ᨨ ᨨ犨␔ �ᆠ ᨨ   ᨨᨨ犨� � ᨨ�ᨨ 矄�矄⏌ᆠᨨᆠ䁸 ᲼꾀 ҈䰘桌 黨

和 졔  





㡰 꾀   ᨨ � �鼀  ᆠ盐   ᨨ盐�  ҈ 犨�    ҈ +  

㡰 꾀   ᨨ ��鼀   ᆠ盐   ᨨ盐�   犨�   ҈ ҈ +  

ᆠ㡰 �ᨨᨨ  ᆠ盐 矄 ᨨ盐� ҈ �矄 �   �鼀矄 >㡰  꾀ᆠ�ᆠ盐� 矄盐 ᆠᨨ犨�ᨨᨨ�矄犨�矄 ᨨ ᨨ鼀 犨ᨨᨨᨨ矄ᨨ 꾀 꾀矄矄 ᨨ犨 �   ��盐꾀  ᨨ� ᨨ ᆠᨨ矄矄� � 犨�矄鼀� ᆠ�ᆠ泐� 矄盐 ᨨ鼀ᆠ ᨨ   �ᨨᨨ�矄�    ᨨ  

㡰 꾀㦨 ᆠ盐  ᨨ盐�  矄�矄 ᆠ �矄 

®

㡰꾀盐 � ᨨ鼀鼀� �ᆠ �   ᨨ� 矄� ᨨ   ᨨ  꾀㦨 ᨨᨨ矄矄ᨨ� �ᨨ盐  ᆠᨨ鼀鼀ᨨ  �鼀矄 �矄犨� ᆠᨨ 矄  �盐ᨨᆠ�泐 w�  鼀� �ᆠ � ␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄�矄⏌ ᆠᨨᆠ䁸 ᲼꾀 ҈䰘桌

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 맔 맔 맔  맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔꾀 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 꾀 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 w

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

㡰 鼀 � 盐ᆠ �  ᨨᨨ�矄ᨨᨨ�ᨨ ᨨ  矄盐鼀ᨨ  矄ᨨ  犨ᨨᨨᨨ矄

㡰 鼀�盐 ᨨ  鼀 �鼀盐鼀 鼀 � 盐ᆠ  盐ᨨ ᨨ  ᨨᨨ矄�矄⼄盐ᨨ 鼀�盐 ᨨ 鼀 �鼀盐鼀 鼀 � 盐ᆠ �  矄鼀ᨨᨨᨨ  ᆠ㡰   鼀  � 盐ᆠ  盐 ᨨ ᨨ    ᨨᨨ矄 �矄 ᨨᨨ�ᨨ ᨨᆠᨨ矄w 㡰 ᨨ ᆠ  �ᨨ   盐 �矄鼀 �鼀盐鼀犨      ᨨ  ᨨᨨ矄�矄 �ᆠ盐 ᨨ  ᨨ    꾀�鼀t 㦨鼀� 꾀 B D �  ᆠ�ᆠ盐�矄 ᨨ犨 �   A ��盐�矄ᆠᨨ

ᆠ ᨨB泐 ├泐   � � �V C㦨m ᆠ盐 I t㡰㦨Iᆠᨨ矄  w㡰 犨� I㦨҈꾀 w㦨�  矄҈矄矄 ᨨ犨� ��

R㦨҈W

䰘p  w  ├泐�矄矄犨�ᆠ   ᨨ鼀B ᨨDᨨ犨ᨨ 犨 矄ᨨ 泐A Dᆠᨨ

ᆠ 꾀ᨨᆠ �Q ᨨ犨矄 ᨨ鼀 泐 ᨨᆠ � ᆠᆠ�ᨨ 盐泐ᔼ C 㦨m  㦨҈W   泐�矄 �  犨�  鼀 ᨨ �  �  � 泐  ᆠᨨᆠ 矄鼀  矄㡰 ᲼꾀 ҈桌 㡰 㝐� �盐 ᨨ  鼀 �鼀盐鼀ᆠ �ᨨ  ᆠᆠ�ᨨ 䰘p  ᨨ t = �矄҈맔҈ᔴ w 㡰 ᆠ盐 �   ᨨ  ᆠ�ᆠ盐�盐矄 ᨨ 䰘p t= �矄ᆠᨨᆠ├犨�矄 w ᆠ㡰 ᔼ鼀鼀 �泐 A�矄ᆠᨨ

ᆠ ᨨD ᆠ盐 � R �矄҈A 㡰 Q㦨맔҈ᔴ ҈ LC R 矄   泐矄�ᆠ⼄盐 ��矄� 盐ᆠ ᆠ ᆠᆠ� ᆠ 矄�矄 ᆠ矄ᆠ�泐 ᆠᨨ鼀� �ᨨ 矄㡰 犨 �ᆠ    �鼀 矄�ᨨ 矄ᨨ  ⼄盐 ᆠ泐 ᲼҈黨㜠㝐├矄桌 㡰 ҈⏌RC 㡰 R/L ᆠ㡰 ҈⏌ LC 㡰 C/L �犨�  � �� �ᆠ�ᨨ 矄 ᨨ犨 �   ��盐꾀 t =

8

Comprehension/Passage Based Questions 矄矄�

꾀ᨨ� ᆠ �턼�矄鼀ᨨ� �� ᆠ�ᆠ盐ᨨ�ᨨ  �盐矄 �   㜠泐 犨�   �盐ᨨᆠ�泐w �矄ᆠ ᆠᨨ 矄�  矄 턼w ⼄盐� ᨨᨨᨨᆠ泐� �矄 泐ᆠ盐  꾀盐 � ᨨ鼀 p 鼀� �ᆠ � ᨨ � ᨨ矄�� 㜠 �矄�矄 ᨨ犨矄犨�ᆠ  ᨨ  犨 �ᆠ � ᆠ矄矄ᆠᨨ 矄  ᨨ鼀ᨨ� ᨨ 矄ᆠᨨ  꾀矄矄盐鼀      �盐矄 ᨨ    ᨨ� 鼀� 矄 ᆠᨨ 矄   �ᆠ�ᨨ ᨨ  鼀� �ᆠ � � 盐ᆠ矄 鼀 �  ᨨ�  � 盐ᆠ 鼀 �矄  �  矄 犨ᨨ├ ᨨ 泐 � 盐ᆠ ᆠ�ᆠ � � 鼀ᨨ� �盐 �ᨨ矄��ᆠ �ᨨ盐 ᆠᨨ矄 ᨨᨨᔼ�矄 ├ ᨨ犨   ᨨ ᨨ�� �ᆠ � 鼀� �ᆠ �ᨨ鼀ᨨ鼀  �矄ᨨᨨ�ᨨ ᨨ  �盐鼀ᨨ鼀 盐鼀犨� ᨨᨨ�ᨨ �泐 ᆠᨨ 矄 g ᲼꾀 ҈桌

WWW.JEEBOOKS.IN

EBD_8341 P-228

҈҈

Physics

鼀� �盐 ᨨ  � 盐ᆠ ᆠ�ᆠ � �  ᨨ�  泐� 矄 ᨨ �鼀 盐� � �鼀� ᨨ  鼀� �ᆠ � ᆠ  ��矄   㡰 ᆠ㡰  㡰   

ᆠ  ��  鼀� �ᆠ �ᨨ鼀ᨨ鼀 矄矄ᨨᆠ� 犨�  ᨨ�  ᨨ  �鼀� ᨨ  鼀� �ᆠ � ᆠ  ��矄

㡰

҈

㡰 g턼  ᆠ㡰 g 9 ҈

턼  

턼  

㡰

-g



g 턼 

Assertion and Reason Type Questions

和鼀 㜠҈꾀�ᆠ�ᨨ ᨨ  矄ᆠᨨ�ᨨ  犨�犨ᨨ盐 ᨨ� ᨨᨨ鼀 꾀

 � �ᆠ盐  ᨨ犨矄�  ᆠᨨ�  ᨨ  �ᨨ矄  ᨨ盐�   ᆠᨨ 盐ᆠ� � � � 矄 矄 ᨨ犨 �   ��盐 � �ᆠ  ᨨ ᆠ�  �� ᨨ ᆠᨨ� 和鼀 㜠ᔼ  ᨨ矄�盐�ᨨ  ᆠ盐 �矄� 盐ᆠ �  � �犨 �ᆠ � ᆠ矄犨�   ᨨ� ᨨ ᆠᨨ鼀ᨨ  ᨨ  鼀� �ᆠ � ᨨᨨ 盐ᆠ

� ᨨᆠ�  盐犨  �ᆠ�ᨨ  ᲼䰘桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐 10 Subjective Problems

҈

꾀ᨨ �矄ᨨ ᨨ� ᨨ  �盐矄  盐鼀ᨨ 盐 矄盐 �  �   �矄  ᆠᨨ矄  泐ᆠ泐� �ᆠ 矄  ᨨ   �盐矄 R  �ᆠ├ 矄矄d dR㡰  � LA�ᆠ盐 � 㦨� 矄� w ᨨ犨矄 ᨨ盐�  ᆠᨨ�ᔼ  矄�矄��泐ᨨ  鼀� ᨨ ᆠ泐� �ᆠ矄 �矄r �  � 盐ᆠ ᆠ盐 �   矄  ᲼�㜠㝐├矄桌

҈�

꾀矄⼄盐ᨨᨨᨨ 矄� �a犨� ᆠᆠ�ᨨᨨ ᆠᆠ� ᆠC �矄ᨨᆠ 犨 犨ᨨᆠ盐 ᆠ泐� �ᨨ �犨�矄 矄矄 ᨨ犨  盐ᨨ I�  犨�矄�矄�� 矄I㦨I 矄� wt ᲼㜠㝐├矄桌

㡰 ᔴᆠ盐鼀 �鼀盐鼀ᆠ盐 �  矄⼄盐ᨨᨨ 㡰 犨� 犨 ᆠ �矄ᨨ  盐ᨨ  ᆠᆠ�ᨨ矄�鼀 ҈ 꾀ᆠ �盐ᨨᨨPQRS 鼀  ᨨ鼀盐 � ᨨ鼀犨� 矄  � a犨�  b  鼀矄矄鼀ᔼ�矄 ᨨᨨᨨ盐  鼀PQ犨 �ᆠ 鼀� 矄 � � ᨨ � ᨨ� ᨨ � ├

矄   泐㜠 �矄 矄 ��盐㡰 ├   �ᆠ泐 盐犨 �ᆠ�ᨨ  矄   㜠 �矄 꾀 盐 � ᨨ鼀 鼀� �ᆠ � ur B = �ˆ + kˆ㡰 B  �矄矄�  ��ᨨ  ᨨᨨ�矄  �



  㜠泐  ᆠ盐 ᔼ�矄矄矄  ᨨ盐�  �  ᨨᨨ�矄 ᨨ犨矄  �矄 ᨨ盐 ᨨ矄泐�   ᨨ� ᨨ  ᨨ矄��ᨨ � ⼄盐���盐鼀 ᲼㜠�㝐├矄桌 z

P

Q y

a x

S

R b 㡰 ␔ �矄  �ᆠ�ᨨ ᨨ  ᆠ盐 I � PQ䁸 㡰 �  鼀� �ᆠ ᨨᆠᨨ  鼀RS ᆠ㡰 �   矄矄�ᨨ  ᨨI� 鼀矄ᨨ Bab m ҈䰘 犨ᨨᨨ � ᨨ� ᨨ �矄 �矄 ᆠd ᆠ  � �矄�矄 ᆠ l 盐 � � ᨨ�   ᨨ  泐矄�矄 ᆠR꾀 ᆠ泐ᆠᨨ 盐ᆠ� �ᨨ MN ᨨ 鼀矄矄鼀�矄 ᨨ矄� ᨨ � �矄犨� ᨨ盐 �ᆠ�ᨨ

矄 ��盐㡰 �矄盐 � ᨨ鼀鼀� �ᆠ � ᨨ � 盐ᆠ�ᨨ

B ᨨ鼀ᨨ  ᨨ    �ᆠ � ᨨ  꾀� ᨨᆠF�矄� ᨨ ᨨ MN 矄盐ᆠ   矄 ᨨ 鼀ᨨ矄ᆠᨨ 矄 ᆠ盐  ᨨ犨矄 ᨨ盐� R ᲼҈黨㜠㝐├矄桌

�㡰 �  ᨨᆠ�泐ᨨ  ᨨ   �  ᨨᆠF 矄 盐 ᆠ�ᨨ ᨨ   �矄 ᆠx ᨨ  ᨨ  ᨨ鼀R ��㡰 ␔  ᆠ�ᨨ  ᨨ  犨ᨨ├ ᨨ  矄ᆠᨨ  泐F �矄 ᆠᨨ  � ᨨ 䁸

WWW.JEEBOOKS.IN

P-229

Electromagnetic Induction

Answer Key Topic-1 : Magnetic Flux, Faraday's and Lenz's Law ҈ 㡰

 㡰

 㡰

 㡰

� 㡰

 㡰

䰘 㡰

 㡰

黨 㡰

҈҈ 㡰

҈ 㡰

҈ 㡰

҈ 㡰

҈� 㡰

҈ 㡰

҈䰘 ᆠ㡰

҈ 㡰

҈黨 㡰

҈ ҈�㡰 ҈

 ҈㡰

 ҈䰘�㡰   ᨨ�� 

䰘 ᆠ㡰

 㡰

� 矄  盐

҈ ᨨ 盐矄㡰  �㡰

Topic-2 : Motional and Static EMI and Application of EMI ҈ 㡰 ҈҈ 㡰  盐

 㡰

 㡰

҈ 㡰 ҈ 㡰 ҈  㡰  㡰

 㡰

� ᆠ㡰

 㡰

҈ 㡰 ҈� 㡰 ҈ 㡰   㡰  ᆠ 㡰 � ᆠ㡰

䰘 ᆠ㡰

 ᆠ㡰

҈䰘 㡰

҈ 㡰

黨 㡰

҈ 㡰

҈黨 맔҈矄҈꾀

Topic-3 : Miscellaneous (Mixed Concepts) Problems ҈ 㡰

 㡰

 㡰

҈҈ 㡰

҈ 㡰

҈ 㡰

 㡰

� 㡰

 ᆠ㡰

䰘 ᆠ㡰   㡰

黨 ᆠ 㡰 ҈ ᆠ㡰

WWW.JEEBOOKS.IN

EBD_8341 P-230

Physics

Alternating Current

21

Topic-1 : Alternating Current, Voltage and Power 1 ҈



MCQs with One Correct Answer

꾀  � �ᨨ�v t㡰㦨矄� ҈Àtᨨ�矄� ᨨ盐泐矄�矄�ᨨ ᨨ �W �鼀├  ᨨ  ᆠ盐  ᨨ�矄 ᨨ鼀  ᨨ  ├盐ᨨ ├ 盐�矄 ᲼㝐� 꾀�҈黨ᔼ桌 㡰 �鼀矄 㡰 鼀矄 ᆠ㡰 䰘鼀矄 㡰 鼀矄 꾀矄鼀ᆠ�ᆠ盐ᨨᨨᨨ 犨�ᨨ  �盐矄a�矄ᨨᆠ   ᆠ ᨨ 鼀盐ᆠ �ᆠ�ᆠ盐犨�ᨨᨨᨨ  �盐矄b  犨ᨨᨨᨨ矄�  矄鼀  ᨨ盐ᨨᨨᨨ  �盐矄 bᆠ�矄  � �ᆠ盐 ᔼ㦨ᔼᨨᆠᨨ矄 w㡰 鼀 � 盐ᆠ �  矄鼀�

ᨨᨨ�矄 泐 ᲼㝐� 졠 � 꾀�҈䰘桌

㡰

 pm ᔼᨨ    w 矄� w㡰 㡰 pm ᔼᨨ   w ᆠᨨ矄 w㡰    

ᆠ㡰 pm ᔼᨨ 

 w 矄� w㡰 



pm ᔼ ᨨ   w ᆠᨨ矄 w㡰 

꾀矄� 盐矄ᨨ� ᨨ� 㡰㦨҈矄�  �㡰�矄� ᆠᨨ矄矄 盐� 盐ᆠ ᆠᨨ 㦨 ᆠ盐  ᨨ盐�   ᆠᨨ��矄 ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ҈ᆠᨨ矄 �㡰 㡰 ҈ᆠᨨ矄 �㡰 ᆠ㡰 ҈矄�  �㡰 㡰 ҈矄�  �㡰

Topic-2 : AC Circuit, LCR Circuit, Quality and Power Factor 1 ҈



꾀 꾀ᔴᆠ�ᆠ盐� 矄R㦨҈WC㦨m  L㦨鼀 ᆠᨨ

ᆠ � 矄�矄 ⼄盐�泐 ᆠᨨᨨ  ᆠ�ᆠ盐��矄 ᲼㝐� 和 ᔼ㡰桌 㡰  㡰 � ᆠ㡰  㡰  꾀矄�矄L㜠Rᆠ�ᆠ盐��矄ᆠᨨ

ᆠ ᨨ泐ᨨ 鼀 Vᔼ  ᆠ�ᆠ盐��矄矄犨�ᆠ  ᨨ t㦨   �鼀犨 �ᆠ   æ ҈ö  �泐矄ᨨ �  � 盐ᆠᨨ ᆠ 矄 ç ÷ �鼀矄ᨨ �矄 è nø 鼀 �鼀盐鼀盐�矄 ᲼㝐� 和 ᔼᔼ㡰桌 L æ n ö ÷ 㡰 R  ç è n -҈ ø L æ n ö ÷ ᆠ㡰 R  ç è n +҈ø



m � 矄�矄 �鼀� 犨 �ᆠ  矄�矄 ᆠ  ᆠᆠ�泐⏌ ᔴ㡰犨��  泐҈ ᔴ 矄矄盐鼀 ᨨᨨ矄矄 ᨨ  ᨨ 矄盐ᨨ盐 � �矄㡰�矄ᆠᨨ矄ᨨ

MCQs with One Correct Answer

L æ n +҈ö  ç ÷ 㡰 R è n -҈ ø

L æ n -҈ ö  ç 㡰 ÷ R è n ø 꾀䰘�  鼀矄㡰矄ᨨ盐ᆠ�矄ᆠᨨ

ᆠ ᨨ矄�矄 ᆠᨨ ҈W � 盐ᆠ ᆠᨨ ҈ ᆠᆠ� ᆠᨨ ҈

᲼㝐� 和 ᔼ㡰桌 

�

㡰 ҈矄 㡰 �矄 ᆠ㡰 �矄 㡰 矄 꾀 � 盐ᆠ ᆠᆠᨨ� 矄ᆠ ᆠᨨ ҈W␔   꾀ᔴ 矄�� ᨨ  ⼄盐 ᆠ泐҈ �矄� ᨨ ᆠᨨ� � ᨨ� 矄 ᆠ盐 泐�  矄 㜠� 盐ᆠ ᆠᨨ  ᆠᨨ��矄 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 ҈҈맔҈

㡰 ҈҈맔҈҈

ᆠ㡰 ��맔҈�

㡰 䰘맔҈䰘

ᔴᨨ 矄�   ᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐ᔼ  矄犨�ᆠ 和�矄ᆠᨨ矄 㦨   鼀ᨨ盐 ᨨ ᆠ � 矄矄矄 L  ᨨ盐�  泐犨 㦨  t = �矄 R ᲼㝐� ҈꾀�҈黨ᔼᔼ桌

WWW.JEEBOOKS.IN

P-231

Alternating Current

黨

҈㡰ᨨ矄  矄 �  ᆠ犨 ᔼ҈ ᔼ�矄 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰  㡰  ᆠ㡰 黨 㡰  ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 

㡰

ᆠ㡰 

䰘EL R

EL

㡰



䰘EL

䰘 R 

和

EL



R



和҈

䰘R 

e

꾀   泐 � 盐ᆠᨨ ᆠᨨ� �矄 ᆠᨨ

ᆠ  ᨨ  ҈ ᨨ 鼀 矄�矄 ᆠ� 矄�矄矄矄 ᨨ犨 �  ��盐 �鼀犨 �ᆠ  ᨨ  �矄矄��ᨨ  ᨨ   �泐 ᨨ盐矄 㡰 ᆠᨨ矄矄 矄�矄 ᆠ�矄⼄盐ᨨ 犨 �ᆠ 鼀� �ᆠ �泐�矄 矄ᨨ �  � 盐ᆠᨨ�矄 ᲼㝐� 꾀�҈黨ᔼ桌

 矄犨�ᆠ 和҈�矄ᆠᨨ矄 �鼀㦨  矄犨�ᆠ 和�矄 ├ᨨ 꾀矄ᨨ鼀�鼀 㡰 矄犨�ᆠ 和҈�矄ᨨ   和�矄ᆠᨨ矄   �ᨨ盐ᨨ  ᆠ盐 ᔼ矄 盐 ᆠ�ᨨ

ᨨ �鼀��矄�� 泐 ᲼㝐� ҈҈ ҈黨ᔼᔼ桌 ᔼ

㡰

 㡰 ln 

䰘



҈ 㡰 ln ᆠ㡰 ln  㡰 ln   ᔼ    ��盐 矄 ᨨ犨   ᆠ�ᆠ盐� ᆠᨨ � 矄 犨ᨨ �  �ᆠ 矄�矄ᨨ矄犨� 矄�矄 ᆠ 㦨�W  � 盐ᆠ ᆠ犨�  㦨鼀꾀 � 泐ᨨ ҈��矄ᆠᨨ

ᆠ �  ᆠ�ᆠ盐� ␔ 犨� ᆠ盐  ᨨ盐�  泐ᨨ �   矄犨�ᆠ �矄ᆠᨨ矄 䁸 ᲼㝐� ҈ ҈黨ᔼ桌

㡰 졠

졠

 ᔼ



 㡰

ᆠ㡰 졠



졠









҈ ᔼ ᔴᆠ�ᆠ盐� � 盐ᆠ ᆠ㦨鼀 ᆠᆠ� ᆠᔴ = 100 m ᔼ ᨨ� t㡰㦨҈矄� ҈t㡰�矄� ᨨ  ᆠ�ᆠ盐� ᆠ盐 �  ᆠ�ᆠ盐��矄�� 矄



᲼㝐� 黨 ҈黨桌

㡰 ��꾀

㡰 �ᆠᨨ矄҈ ᆠ㡰 �ᆠᨨ矄҈

㡰 䰘�꾀

ᆠ㡰 꾀

㡰 꾀

㡰 ҈ᆠᨨ矄҈ 㡰 �矄� ҈

҈҈

ᔼ

  ҈

ᔴ 

ᔼ҈

~

  Ҙ   㦨W㦨  ҈  ҈㦨҈Wᔴ盐 � 㜠 ҈ �矄ᔼ҈ � ᔴ㜠  ��矄

ᔼ  ᨨᆠ�ᆠ盐�ᔴ㦨

ᔼ ᨨ�ᨨ 꾀ᔴ矄ᨨ盐ᆠ�矄�� 泐㦨   矄�

꾀矄矄 ᨨ犨 �   ��盐泐ᨨ 鼀 Î�矄ᆠᨨ

ᆠ ᨨ

� 盐ᆠᨨL 矄�矄 ᆠR� 矄�矄 矄犨�ᆠ �矄ᆠᨨ矄  t㦨 ᨨᆠ �  ᨨ犨矄 ᨨ鼀 泐犨 t 㦨 t㦨tc tc�矄 �鼀ᆠᨨ 矄 ᨨ  ᆠ�ᆠ盐�㡰�矄 ᲼㝐�  ҈黨ᔼᔼ桌 Î L æ ҈ö ÎR 㡰 㡰 ç҈ - ÷ R è e ø eL ᆠ㡰

ÎL R





ÎR eL

WWW.JEEBOOKS.IN

EBD_8341 P-232

҈

҈

҈

҈�

Physics

꾀ᔴ ᆠ�ᆠ盐� 矄�├ 鼀  鼀ᨨ �ᆠᨨ矄ᆠ�ᨨ ᔴᨨ鼀� � � 犨�    泐矄�ᆠ 矄� �㜠鼀矄矄 鼀 ᨨ矄ᆠ�ᨨ � � 鼀� � ᆠᨨ 矄  �b   ᆠᨨᆠ ⼄盐� ᆠ犨ᨨ盐  ᲼㝐� 䰘 ҈黨ᔼ桌 㡰 L«mC«kR«b ҈ ҈ ҈ 㡰 L« C« R« b m k ᆠ㡰 L«kC«bR«m ҈ 㡰 L«mC« R«b k 꾀 鼀 ᨨ �矄� �鼀t㦨ᨨᆠ�ᆠ盐�ᆠᨨ � � � � 矄�矄҈鼀� 盐ᆠᨨ �W矄�矄ᨨ �ᨨᨨ   ᆠ盐 矄�鼀t 㦨¥ t㦨矄�矄ᆠᨨ矄ᨨ

҈ 꾀 � 盐ᆠᨨ 㦨㡰 矄�矄ᨨ 㦨҈�├W㡰 ᆠᨨ

ᆠ � 矄�矄ᨨ泐ᨨ ҈�鼀 � ᆠ�ᆠ盐� 矄 ᨨ犨 ᨨ犨 ├泐⧤҈ 矄 ├ᆠᨨ矄  ᨨᨨ � �鼀  㦨⧤҈ �矄ᨨ   ├泐⧤�矄 ᆠᨨ矄 矄�鼀盐 ᨨ盐矄泐꾀㦨鼀矄 ᆠ盐 �  ᆠ�ᆠ盐�犨�

├e㦨䰘黨㡰

㡰 䰘鼀꾀 㡰 䰘鼀꾀 ᆠ㡰 ҈鼀꾀 㡰 䰘鼀꾀 ҈黨 꾀 ᔴ ᆠ�ᆠ盐��矄⼄盐� ᨨ 鼀  盐盐鼀ᔼ 

ᔴ  ᆠ�ᆠ盐�   ᆠᆠ�ᨨ �矄 ᆠ �  ᨨ 턼    

ᆠᨨ

ᆠ ᨨ   矄矄 ᨨ犨 ᨨ犨

᲼㝐� 䰘 ҈黨ᔼᔼ桌

㡰 ҈ 㡰 ҈҈� ᆠ㡰 ҈ 㡰  ᔼ  ᆠᆠ�ᆠ盐� � 矄  ᨨ盐矄鼀  ᆠ盐  ��  泐 e㦨҈矄� t

pö æ �㦨矄�  ç   - ÷ ø è ᔼ ᨨ ᆠ泐ᆠᨨ ᆠ �ᨨ犨ᆠᨨ 矄盐鼀 泐  ᆠ�ᆠ盐�  犨矄矄ᆠ盐 矄ᆠ�泐 ᲼㝐� ҈桌 ҈ 㡰 �␔҈꾀 㡰 ␔҈꾀  � ␔  ᆠ㡰 㡰 �␔  ᨨ  ᔴᆠ�ᆠ盐� � 犨� ᨨ�ᨨ 鼀�盐 v鼀 ⼄盐 ᆠ泐w㦨

҈

 ᆠ盐  ��矄矄ᨨ  ᆠ  ᔴ ⼄盐�泐 ᆠᨨQ�矄�� 泐 ᲼㝐� ҈桌

ᔴ w  w 㡰 ᆠ㡰 㡰 w  wᔴ㡰 꾀矄� 盐矄ᨨ� ᨨ�ᨨ ├盐  �盐 ⼄盐 ᆠ泐⏌矄�矄� ᨨ矄�矄ᔴ ᆠ�ᆠ盐�෌�

  㦨�W㦨�鼀 ᔴ㦨҈m  ᨨ�鼀  ᆠ    矄 �  ᆠ 犨    ᨨ� ᆠᨨ矄矄   矄ᨨ盐ᆠ  ᆠ盐 犨�矄ᆠ�泐 ᲼㝐� 졠 � 꾀�黨҈䰘桌

 ( � @ ҈� )

᲼҈�桌

 ⧤

� 㡰 ҈W   ҈ æç ö÷ 㡰 䰘W  � è ø

æö � ᆠ㡰 ҈W  ҈ ç ÷ 㡰 䰘W   ҈ æç ö÷ èø è ø ҈䰘

꾀 ᆠ鼀⼄盐�矄 �ᆠᆠ盐 ᨨ ҈꾀ᨨ 盐 ᆠ�ᨨ ᔼ ��矄ᆠᨨ

ᆠ ᨨ 鼀矄㡰� 꾀ᔴ 矄盐泐 矄�矄� 盐ᆠᨨ    ᨨ�ᨨ犨ᨨ├�矄ᆠᨨ矄ᨨ ᲼㝐� ҈桌 㡰  㡰 � ᆠ㡰  㡰 

⧤҈

҈�





ᔴ ᔼ 矄盐  ᨨ矄� 矄ᨨ  矄⼄盐ᨨ 鼀 �鼀盐鼀ᆠ � 턼 㝐 ᨨ  ᆠᆠ�ᨨ犨� �鼀 㡰 ᨨ犨ᨨ �   盐矄҈  ҈>㡰ᨨ   犨 �ᆠ ᨨ   ᨨᨨ犨� � 矄 矄 �矄� ᆠᨨᆠ泐䁸 plᨨts are schemat�c and nᨨt drawn tᨨ scale㡰 ᲼㝐� ҈�桌

(

)





㡰

턼㝐





㡰

턼㝐

턼 ᨨᨨ ҈  㡰

t

t

㡰

҈

҈�├W



ᆠ㡰

턼㝐





턼 㡰 㝐 ҈



t



t

 ᨨ ᔴ ᆠ�ᆠ盐�矄 ᨨ犨   ᆠ盐 �矄ᨨ矄 ᨨ  � ᨨ�꾀  ��ᨨ ᆠᆠ�ᨨᔴ 犨  ᨨ�  犨�  ᆠᆠ�ᨨᔴ矄 �  ᆠ�ᆠ盐� 鼀├矄   ᨨ犨 ᆠᨨ ᨨ    ᆠ�ᆠ盐� 盐 �泐  ᆠᆠ�ᨨ ᔴ 鼀盐矄    ᆠᨨ

ᆠ  �   ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 





~ 㦨矄�  w 

WWW.JEEBOOKS.IN

P-233

Alternating Current

C

㡰 矄�矄犨� ᔴ   矄鼀� �盐 

(w2 LC –1)

㡰 矄�矄犨�  ᔴ  矄 鼀� �盐 

1 - w2 LC w2 L

ᆠ㡰 犨� ᔴ  矄鼀� �盐 

҈

1 - w2 LC w2 L

C 㡰 犨� ᔴ  矄鼀� �盐  2 (w LC - 1) ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨   ᨨ� �ᔴ�矄├ᆠᨨ

ᆠ ᨨᨨ�  �꾀� ᆠ盐  ᨨ犨� � ᨨ盐�   ᆠ�ᆠ盐� ᆠᨨ鼀矄 ᆠᨨ 矄  꾀 犨  矄盐  泐 ᨨ�  �ᔴ�矄 �矄ᆠᨨ

ᆠ  ᨨ鼀ᨨ� �꾀 ᆠᨨ

ᆠ ᨨᨨ� � �鼀㦨 �ᨨᨨ  ᨨ�ᆠᨨ矄矄矄�矄 ᆠ   � 盐ᆠᨨ㦨⏌ 犨�⼄盐ᨨ ᲼㝐� ҈桌 꾀





 

㡰 



 ҈- 

㡰 ҈

ᆠ㡰 ҈



҈-  

␔     鼀矄 ᨨ�矄  ᔴ      鼀矄盐 矄ᆠ�泐ᆠᨨ矄矄 � 盐ᆠᨨ ᆠᆠ�ᨨᔴ   矄�矄ᨨ � 矄�矄ᔴ ᆠ�ᆠ盐�ᆠᨨ

ᆠ ᨨ 꾀ᔴ矄ᨨ盐ᆠ ��矄 ᨨ盐   �ᨨᔴ 㦨҈ᔼ  鼀矄 ᨨ�ᨨ  꾀ᔴ矄ᨨ盐ᆠ矄�矄҈  �矄ᆠᨨ矄ᨨ ᲼㝐� 졠 � 꾀�黨҈桌 㡰 � 㡰 䰘 ᆠ㡰 黨 㡰 ҈ ᔼ  ᔴ ᆠ�ᆠ盐�矄矄 ᨨ犨 ᨨ犨ᨨ 矄犨�ᆠ 矄ᨨ

� ��泐ᨨ犨矄犨�ᆠ 和҈�矄ᆠᨨ矄 和├ᨨ  ⼄�矄ᆠ � ᨨ  ᆠᆠ�ᨨ t㦨 ᔴ�矄ᔴᆠ���鼀ᆠᨨ 矄 㡰 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 �矄ᆠᨨᆠ䁸᲼㝐� ҈桌 

 꾀 矄�矄   ᆠ�ᆠ盐� �矄 ᆠᨨ

ᆠ  ᨨ   ᆠ 矄ᨨ盐ᆠ ᨨ ⼄盐 ᆠ泐w  � 盐ᆠ�ᆠ ᆠ�矄⼄盐ᨨ 꾀 ᆠᆠ� ᆠᨨ ᆠᆠ��ᆠ ᆠ⼄盐ᨨ �矄  �

矄�矄犨�    �ᨨᨨ   犨ᨨ犨 ᆠᨨᨨ  ᨨ ᨨ �矄 ᲼㝐� 졠 � 꾀��҈桌 㡰

 

 �

㡰

ᆠ㡰

 



� 

� ᔼ 矄�矄㜠ᔴ㜠 ᆠ�ᆠ盐�ᔴ㦨҈҈҈  㦨҈� 泐   㦨҈졠 鼀犨  ᆠᨨ 矄 ᔴᨨ�쟼�矄� ᨨ ᆠ�ᆠ盐� ᆠᆠ�ᨨᆠ⼄盐�矄ᆠ �҈ 黨ᔴ  ᔴ矄ᨨ盐ᆠ�矄ᆠ 泐矄� 盐矄ᨨ� ᨨ�矄ᨨ盐ᆠ�

犨 �ᆠ  ├ᨨ�쟼�矄⼄盐ᨨ ᆠᨨ 矄 ᔴ ᨨ� 쟼 꾀 矄ᨨ  ᆠ   ├ 盐 ᨨ    ᆠ � ᆠ⼄盐� 泐 ᆠᆠ�ᨨ犨� ᲼㝐� 졠 � 꾀�҈桌 㡰 ҈҈�ᔴ 㡰 ҈ᔴ ᆠ㡰 ҈҈ᔴ 㡰 ҈ᔴ  꾀 꾀ᔴ ᨨ� 矄ᨨ盐ᆠᨨ � �盐 ⼄盐 ᆠ泐w   �   鼀�盐  V �矄 ᆠᨨ

ᆠ � 矄�矄 犨�  ᆠᆠ� ᆠ C     ᆠ�ᆠ 盐 ᨨ  矄�矄 ᆠ R � 盐ᆠ ᆠ ᨨ㡰␔  w�矄� ᆠ矄 ᲼҈桌 㡰  盐�ᨨ犨矄 �鼀鼀 㡰  盐�ᨨ犨矄��  ᆠ㡰 ᨨ�鼀  ᆠᨨ  ᆠ�ᆠ盐��矄盐 ᆠ  � 㡰 ᨨ�鼀  ᆠᨨ  ᆠ�ᆠ盐�� ᆠ矄矄 䰘 �  �鼀ᆠᨨ 矄  � m矄㡰 ᨨ �� RC ᆠ�ᆠ盐�矄�   �� ᨨ 矄ᆠ�泐 ᲼㜠㝐҈桌

 ҈

ᔴ҈

 ᔴ



和҈ ᔴ

和

 㡰 ␔ᨨ├ ᨨ  泐   泐 �矄   ᨨ     �泐 �矄矄� �  矄�矄ᨨ 㡰 꾀㦨t⼄㦨ᔴ⏌ ᆠ㡰 At, t = 2t⼄㦨ᔴ ҈㡰 㡰 꾀㦨t⼄㦨ᔴ ҈҈㡰

R҈ = ҈W R = W C҈ = mF  C = mF     㡰 ҈ 㡰 ҈  ᆠ㡰 ҈ 㡰  ҈ 黨 黨 黨 黨  ␔   AC 矄ᨨ盐ᆠᨨ 鼀 e㦨E矄� ҈t㡰�矄ᆠᨨ

ᆠ ᆠᨨ矄矄ᆠ�ᆠ盐�  矄 �  ᆠ犨  鼀 e   ᆠ盐 ��  ᆠ�ᆠ盐��矄ᨨ矄 ᨨ p 4 矄 矄 ᨨ犨 �   ��鼀ᔼ  ᆠ�ᆠ盐�ᆠᨨ 矄�矄矄ᨨ矄矄�泐ᨨ 泐 ᨨ R㜠CᨨR㜠LᨨL㜠C � 矄�矄 �  �ᨨ 矄 �犨

᲼和桌  犨ᨨ鼀 矄

WWW.JEEBOOKS.IN

EBD_8341 P-234

Physics

㡰 R 㦨҈k W C 㦨҈ҘF



ᆠ�ᆠ盐�ᨨ  �矄  矄鼀鼀� �盐 ᨨ   ᆠᨨ鼀ᨨ� ᨨᆠ 鼀 㡰  ᨨ��矄矄� �ᆠ �    ��盐 ᔼ� ᨨ 鼀盐盐 � 盐ᆠ ᆠ 犨    � 盐ᆠᨨ矄 ᆠ盐 I�  鼀� 犨�ᆠ 矄�矄 鼀 �鼀盐鼀鼀� �盐 I鼀  �鼀t㦨 t ␔ �ᆠ  ᨨ   ᲼꾀 ҈桌 ᨨᨨ犨� �矄鼀 矄�矄 㡰盐䁸



㡰 R 㦨҈k W C 㦨҈ҘF ᆠ㡰 R 㦨҈k W L㦨҈H  㡰 R㦨҈k W L㦨҈H 2 黨

犨ᨨ� 盐ᆠᨨ矄҈ � 盐ᆠ ᆠ҈鼀�  矄�矄 ᆠ W㡰  � 盐ᆠ ᆠ鼀�  矄�矄 ᆠW㡰 矄�矄ᨨ  矄�矄 ᆠ҈W㡰ᆠᨨ

ᆠ �  ᆠᨨ矄矄�泐 ᆠ�ᆠ盐��矄矄犨�ᆠ  ᨨ �鼀㦨  �ᨨ ᨨ  鼀 �鼀盐鼀ᨨ  鼀� �鼀盐鼀 ᆠ盐  ᔼ鼀 ⏌ᔼ鼀� 㡰 犨  ᨨ鼀 泐�矄 ᲼꾀 ҈桌 3



꾀ᨨ ᆠᨨ鼀ᆠ�ᆠ盐��矄矄 ᨨ犨 �   ��盐꾀矄ᨨ鼀 � 矄  盐ᨨ ᆠ盐 ᔼ�矄҈꾀 ��矄 ᆠ矄� � rateof 10꾀矄҈ 盐ᨨ  ᨨ � �  ᆠ턼 � ᨨ矄㡰 � 矄 �矄힘힘힘힘힘힘 ᲼㝐� 和 ᔼ㡰桌 

V

㦨W

V R

㡰 I鼀 㦨

L L     㡰 t㦨 R R  ᔼ  ᆠ�ᆠ盐�矄 ᨨ犨 㦨҈mᔴ㦨҈m   㦨҈├W 泐 ᆠᨨ

ᆠ � 矄�矄犨�  ᆠ矄ᨨ盐ᆠ㦨矄� w矄 矄 ᨨ犨 ␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄�矄⏌ᆠᨨᆠ䁸 ᲼꾀 ҈䰘桌

~  矄� w 㡰

᲼㝐� 和 ᔼᔼ㡰桌

� 盐ᆠᨨ矄ᨨ 犨ᨨLRᆠ�ᆠ盐�矄ᆠ   ᨨᆠ ᨨ  矄 矄 ᨨ犨  �    ��盐  盐矄 ᨨ    矄 㜠 � 盐ᆠ ᆠ ᨨ    � 盐ᆠᨨ矄 矄�矄 ᆠ矄 鼀盐盐㜠 � 盐ᆠ ᆠ � ᨨ�矄矄ᆠ� � �  ��

ᆠ�ᆠ盐�꾀 ᨨ  矄犨�ᆠ 矄ᆠᨨ矄 矄�鼀盐 ᨨ盐矄泐  ᨨ犨ᨨ├ ᨨ 泐 �矄�� 矄 � 盐ᆠ EMF�  � 盐ᆠᨨ矄泐 �鼀 ᆠ盐 矄ᆠ  � 矄 泐矄盐矄�矄힘힘힘힘힘힘힘힘鼀 ᲼꾀 桌

 ᆠ盐  犨�  �   矄 犨�    ᨨ� � w㦨҈ 矄㜠҈ 㡰  ⼄盐 ᆠ泐犨 �ᆠ  ᆠ盐 犨��  矄 犨�  ᨨ��矄�   ᨨ  ᆠ㡰 꾀 w ~   ᆠ盐  ᨨ犨� � ᨨ盐�   ᆠ�ᆠ盐� ᆠᨨ鼀矄 泐 ᨨ 㡰 꾀 w >> ҈    矄㜠҈   ᆠ�ᆠ盐�  矄 �├  ᆠᆠ�ᨨ � ᔼ    ��  ᆠ�ᆠ盐�  꾀ᔴ 矄ᨨ盐ᆠ 矄 w 㦨 ҈  ⏌矄 ᔴᨨ 矄� � � � 盐ᆠᨨ ᆠᆠ�ᨨᨨ�   ᆠᨨᆠᆠ ᨨ�ᆠ 矄㡰�矄 㡰 ᲼҈桌 ҈00 m

V 㦨

L 㦨鼀

M 㦨�鼀

L҈ 㦨҈鼀

V҈ 㦨�

҈00W

R 㦨҈W

0.5 H



V R

 = ҈m ᔴ = ҈m = ҈├W

æ ö çè ÷ø m   盐ᨨ  �矄힘힘힘힘힘힘 p

R҈ 㦨�W

S

ᆠ㡰 t㦨

҈ ᔼ 矄�矄 ᆠ�ᆠ盐�ᨨ犨ᨨ ␔�矄 �矄矄�  ᨨ鼀 矄ᨨ盐ᆠᨨ ��  ᨨ犨 ᆠᨨᨨ  ᆠ�ᆠ盐��矄ᔼ

ᨨ ᨨ� � ᨨ犨 ᆠᨨᨨ盐 �泐ᆠᆠ�ᨨᨨ 盐ᔴ �矄    �  矄�矄ᨨ    ├� �  盐ᔴ 矄



L

V







R

I

㡰 I鼀 㦨

Numeric Answer

㦨�鼀 ᔼ

L

R

Integer Value Answer

I

~

50 W

0 V

㡰 ᆠ盐  ᨨ盐�  ᆠ�ᆠ盐�I�矄꾀 㡰 ᆠ盐  ᨨ盐�  ᆠ�ᆠ盐�I�矄  A

6 

MCQs with One or More than One Correct Answer

ᔼ    ��盐 ᨨ犨  矄犨�ᆠ 矄S҈   S  ᆠᨨ矄 矄�鼀盐 ᨨ盐矄泐t㦨 ᆠ盐 矄矄ᨨ ᨨ犨�  

ᆠ㡰 ᨨ�ᆠᨨ矄矄҈W 矄�矄ᨨ㦨 ҈ V 㡰 ᨨ�ᆠᨨ矄矄�W 矄�矄ᨨ㦨҈

WWW.JEEBOOKS.IN

P-235

Alternating Current

10 Subjective Problems 

ᔼ   ��盐ᨨ ᆠ矄A B ᨨ ⼄盐鼀  � R ᨨ 犨 �ᆠ ᨨ � �  ᆠᆠᨨ矄矄泐A犨� ᨨ ᨨ ��鼀  矄犨�ᆠ �矄ᆠᨨ矄 ᔼ  矄�矄 ᆠᨨ �矄A  B r҈ r矄ᆠ�泐 r҈>r㡰 ᲼㜠㝐├矄桌

䰘

ᔼ  矄�矄 LR ᆠ�ᆠ盐�  L 㦨 �鼀 R㦨҈҈W㡰� 鼀 矄ᨨ盐ᆠ V㦨V矄� w㡰ᨨ Vrms㦨  ⼄盐 ᆠ泐 �   �矄 �  �    ᆠ盐 鼀�盐 �  ᆠ�ᆠ盐�    矄 ᨨ  ᆠ盐  犨� 矄ᆠᨨᨨ�犨ᆠ盐 㜠�鼀� ᨨ �� � p㦨⏌䰘㡰 ᲼㜠㝐├矄桌 꾀  � 盐ᆠᨨ ᨨ  � 盐ᆠ ᆠL 㦨 鼀 矄�矄ᨨ矄 L E ᨨ  矄�矄 ᆠ矄 R ҈ R҈ 㦨W R㦨W  ᆠᨨ

ᆠ  ᨨ S R 泐ᨨ



鼀 E㦨҈矄矄 ᨨ犨 �   ��盐 �  矄�矄 ᆠ ᨨ  泐�矄 ���� 矄犨�ᆠ S�矄ᆠᨨ矄 �鼀 t㦨 ␔ �矄 ᨨ � ᨨᆠᨨ矄矄L矄 盐 ᆠ�ᨨ ᨨ �鼀䁸꾀    矄 泐矄 �矄 ᆠ     矄犨�ᆠ  �矄 ᨨ  ␔ �矄  �ᆠ�ᨨ   鼀� �盐 ᨨ ᆠ盐   ᨨ盐� R҈矄 盐 ᆠ�ᨨ ᨨ �鼀䁸 ᲼҈㜠�㝐├矄桌 黨 꾀矄ᨨ ᨨ�  矄 � 盐ᆠ ᆠᨨ ҈  泐 矄�矄 ᆠ ᨨ ᨨ 鼀ᔼ�矄ᆠᨨ

ᆠ ᨨ҈ᨨ泐ᨨ犨ᨨ �犨� �├ ᨨ 鼀� �ᆠ �泐ᨨᆠ ҈⏌ᨨ �矄鼀 �鼀盐鼀 盐䁸 ᲼҈黨黨㜠㝐├矄桌  꾀ᆠ�ᆠ盐�ᆠᨨ � � �犨ᨨᨨ矄��ᨨ 矄犨�ᆠ 和�矄矄 ᨨ犨 �

�� ᲼҈黨黨҈㜠졔㝐├矄桌

㡰 矄犨�ᆠ  S �矄� ᨨ矄��ᨨ �҈ �  ᨨ � �  ᆠVA VB   ᨨ ᨨ 盐ᆠ�ᨨ ᨨ ᨨ盐 � R҈ 㡰 ᔼ  ᨨ犨 矄犨�ᆠ S �矄盐� ᨨ矄��ᨨ t㦨 � �㡰矄 泐ᆠ盐 � R ��㡰 �鼀犨  ᆠ盐 � R�矄   矄 泐 盐꾀矄ᨨᆠᆠ盐  �泐矄ᨨ �  � 盐ᆠᨨ L  �鼀

Topic-3 : Transformers and LC Oscillations 1 ҈

ᨨ 㡰

MCQs with One Correct Answer

ᨨ �� � 盐ᨨ�犨 ᨨ鼀� t㡰 ᨨ盐盐 ᨨ�犨 ᨨ鼀ᨨ t㡰ᆠᨨ矄矄 ᆠᆠ�ᨨ�矄ᆠᨨᆠ泐 �ᆠ 泐 ᲼㝐� 和 ᔼ㡰桌

ᆠ㡰  �m矄 ᨨ 㡰

҈├W  졔� �m 矄 �m



҈  t

졠 㡰



矄





㡰

㡰

 �m矄 ᨨ 㡰

҈m矄 ҈5m矄

�m矄

҈m矄 ҈5m矄

҈m矄 ҈5m矄

㡰  꾀 ᆠ㡰  �꾀 



꾀 矄 ᨨ鼀ᆠᨨ 矄�矄� �ᨨ 盐 矄�  �鼀泐 ҈�盐 矄�  矄ᆠᨨ 泐��矄ᨨ盐盐ᨨ犨ᨨ ├␔ ᔼ  ᆠ盐 �  矄ᆠᨨ 泐ᆠᨨ��矄҈꾀   � 盐 ᨨ� ᆠ盐 �  �鼀泐ᆠᨨ�









�m矄

 ᨨ 㡰

҈m矄 ҈5m矄

᲼㝐� ҈꾀�҈黨ᔼ桌 㡰  꾀 㡰  ҈꾀

WWW.JEEBOOKS.IN

EBD_8341 P-236

3.

Physics

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns. The output power is delivered at 230 V by the transformer. If the current in the primary of the transformer is 5A and its efficiency is 90奠, the output current would be: [Main 9 Jan. 2019 II] (a) 50 A (b) 45 A (c) 35 A (d) 25 A

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns, giving the output power at 230 V. If the current in the primary of the transformer is 5 A, and its efficiency is 90奠, the output current would be: [Main Online April 16, 2018] (d) 25 A (a) 20 A (b) 40 A (c) 45 A

4.

Topic-4 : Miscellaneous (Mixed Concepts) Problems 6 1.

A series R– C circuit is connected to AC voltage source. Consider two cases; (A) when C is without a dielectric medium and (B) when C is filled with dielectric of constant 4. The current IR through the resistor and voltage VC across the capacitor are compared in the two cases. Which of the following is/are true? [2011] (a) 7

2.

MCQs with One or More than One Correct Answer

I RA > I RB

(b)

I RA < I RB

VCA > VCB

(c)

(d)

VCA < VCB

Match the Following

You are given many resistances, capacitors and inductors. These are connected to a variable DC voltage source (the first two circuits) or an AC voltage source of 50 Hz frequency (the next three circuits) in different ways as shown in Column II. When a current I (steady state for DC or rms for AC) flows through the circuit, the corresponding voltage V1and V2 , (indicated in circuits) are related as shown in Column I. Match the two [2010] Column I Column II V1

(A) I ¹ 0, V1 is proportional to I

(p)

V2 3m F

6mH

V V1

V2

6mH

(B) I ¹ 0, V2 > V1

2W

(q) V

(C) V1 = 0, V2 = V

V1

V2

6mH

2W

(r) V

V1

(D) I ¹ 0, V2 is proportional to I

(s)

V2

6mH

3m F

V1

V V 2

3m F

1kW

(t) V

WWW.JEEBOOKS.IN

P-237

Alternating Current

Comprehension/Passage Based Questions Passage 1 In the given circuit the capacitor (C) may be charged through resistance R by a battery V by closing switch S1. Also when S1 is opened and S2 is closed the capacitor is connected in series with inductor (L). 8

5.

Given that the total charge stored in the LC circuit is Q0, for t ³ 0, the charge on the capacitor is [2006 – 5M, –2] t ö æp (a) Q = Q0 cos ç + ÷ è2 LC ø

(c) Q = - LC

At the start, the capacitor was uncharged. When switch S1 is closed and S2 is kept open, the time constant of this circuit is t. Which of the following is correct [2006 – 5M, –2] CV (a) after time interval t, charge on the capacitor is 2 (b) after time interval 2t, charge on the capacitor of CV (1 – e–2) (c) the work done by the voltage source will be half of the heat dissipated when the capacitor is fully charged (d) after time interval 2t, charge on the capacitor is CV (1 – e–1) When the capacitor gets charged completely, S1 is opened and S2 is closed. Then, [2006 – 5M, –2] (a) at t = 0, energy stored in the circuit is purely in the form of magnetic energy (b) at any time t > 0, current in the circuit is in the same direction (c) at t > 0, there is no exchange of energy between the inductor and capacitor (d) at any time t > 0, instantaneous current in the circuit

3.

4.

may be V

C L

d 2Q

t ö æp (b) Q = Q0 cos ç ÷ è2 LC ø

(d) Q = -

dt 2

1 d 2Q LC dt 2

Passage 2 A thermal power plant produces electric power of 600 kW at 4000 V, which is to be transported to a place 20 km away from the power plant for consumers' usage. It can be transported either directly with a cable of large current carrying capacity or by using a combination of step-up and step-down transformers at the two ends. The drawback of the direct transmission is the large energy dissipation. In the method using transformers, the dissipation is much smaller. In this method , a step-up transformer is used at the plant side so that the current is reduced to a smaller value. At the consumers' end, a step-down transformer is used to supply power to the consumers at the specified lower voltage. It is reasonable to assume that the power cable is purely resistive and the transformers are ideal with power factor unity. All the currents and voltages mentioned are rms values. [Adv. 2013] 6. If the direct transmission method with a cable of resistance 0.4 W km–1 is used, the power dissipation| (in 奠) during transmission is (a) 20 (b) 30 (c) 40 (d) 50 7. In the method using the transformers, assume that the ratio of the number of turns in the primary to that in the secondary in the step-up transformer is 1 : 10. If the power to the consumers has to be supplied at 200 V, the ratio of the number of turns in the primary to that in the secondary in the step-down transformer is (a) 200 : 1 (b) 150 : 1 (c) 100 : 1 (d) 50 : 1

Answer Key Topic-1 : Alternating Current, Voltage and Power 1.

(d)

2. (a)

3. (b) Topic-2 : AC Circuit, LCR Circuit, Quality and Power Factor

1. (a) 11. (a) 21. (c) 31.

(400)

39.

3.465 s

2. (a) 12. (d) 22. (c)

3. (d) 13. (a) 23. (c)

4. (a) 14. (b) 24. (d)

32. (55)

33. (b, d)

5. (b) 15. (a) 25. (d)

6. (c) 7. (d) 16. (b) 17. (b) 26. (b) 27. (b) 4 (r - r ) 34. (b, c) 35. (a,c) 36. 3 1 2

8. (Bonus) 9. 18. (b) 19. 28. (a) 29. p 37. 20 A, 38. 4

(b) (c) (8)

10. (a) 20. (c) 30. (33)

12e–5t V

Topic-3 : Transformers and LC Oscillation 1.

(a)

2. (c)

3. (b)

4. (c)

Topic-4 : Miscellaneous (Mixed Concepts)Problems 1.

(a,c)

2. A-r,s,t; B-q,r,s,t; C-p,q; D-q,r,s,t

3. (b)

4. (d)

5. (c)

6. (a)

7. (b)

WWW.JEEBOOKS.IN

EBD_8341 P-238

Physics

Electromagnetic Waves

22

Topic-1 : Electromagnetic Waves, Conduction and Displacement Current 1 ҈

MCQs with One Correct Answer

ᨨ ᆠᨨ鼀� �ᆠ犨 鼀� �ᆠ �  ᨨ� x �鼀t�矄 ®





 x t 㡰 = ᲼҈ ´ ҈-䰘 矄� � ´ ҈® x + ҈� ´ ҈҈҈t 㡰k$ 桌 ®

� 矄  ᨨ盐矄ᆠ�ᆠ �  쟼 ᆠᨨ矄ᨨ � �ᨨ  �矄 矄 ᨨ �� ᆠ㦨맔҈鼀矄҈㡰᲼㝐� 和 ᔼᔼ㡰桌 ®  㡰 쟼 x t 㡰 = ᲼ - 矄� � ´ ҈ x + ҈� ´ ҈҈҈ t 㡰 $ 桌 鼀 ®   ҈҈ 㡰 쟼 x t 㡰 = ᲼ 矄� ҈ ´ ҈ x + � ´ ҈ t 㡰 $ 桌 鼀 ®  ҈҈ $  ᆠ㡰 쟼 x t 㡰 = ᲼ 矄� � ´ ҈ x + ҈� ´ ҈ t 㡰 k 桌 鼀 ®  㡰 쟼 x t 㡰 = ᲼ 矄� ҈ ´ ҈ x + ҈� ´ ҈҈҈ t 㡰$�桌 鼀 꾀 ᆠᨨ �矄ᆠᨨ 矄�  ᨨ鼀ᨨᨨ � y㜠 �矄犨�  矄 ᨨ ҈c c�矄 矄 ᨨ �� 㡰�  矄 ᆠᨨ ® ᆠᨨ鼀� �ᆠ 犨 犨 ᨨ矄 ᆠ�ᆠ �  �矄 쟼 = $ 矄� ҈�맔҈䰘t�맔҈x㡰⏌鼀 鼀 �鼀盐鼀鼀� �ᆠ ᨨᆠ � ᆠ 泐 ᆠᨨ 犨� �� c㦨맔҈鼀矄҈ᆠᨨ ᆠ �㦨҈맔҈҈黨ᔴ㡰 ᲼㝐� 和� ᔼ㡰桌 ҈ 㡰 맔҈  㡰 맔҈҈ ᆠ㡰 맔҈҈黨 㡰 ҈맔҈҈黨

ᆠ�ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄��

r 泐 E = E xˆ + yˆ 㡰 矄� kz - wt 㡰 ᔼ矄鼀� �ᆠ � 犨��� 泐᲼㝐� 和 ᔼᔼ㡰桌 E 㡰 - xˆ + yˆ 㡰矄� kz - wt 㡰 c E 㡰  xˆ + yˆ 㡰矄� kz - wt 㡰 c

E xˆ - yˆ 㡰 矄� kz - wt 㡰 c E 㡰  xˆ - yˆ 㡰 ᆠᨨ矄 kz - wt 㡰 c

鼀� �ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄 ur ˆ B =  ´ ҈- 矄� ᲼p y + ct 㡰桌�T

ᆠ㡰



犨 c㦨맔҈鼀矄҈�矄 矄 ᨨ �� 

ᆠᨨ矄ᨨ � �ᆠ�ᆠ � �矄 ᲼㝐� 和 ᔼ㡰桌 ur 㡰 E = 黨矄� ᲼p y + ct 㡰桌kˆ ⏌鼀 ur 㡰 E = -҈- 矄� ᲼p y + ct 㡰桌kˆ ⏌鼀 ur ᆠ㡰 E =  ´ ҈  矄� ᲼p y + ct 㡰桌kˆ ⏌鼀 ur 㡰 E = -黨矄� ᲼p y + ct 㡰桌kˆ ⏌鼀 �

 ᆠ�ᆠ �  ᨨ     ᆠᨨ鼀� �ᆠ 犨 ᨨ�� � ᨨ �   x �ᆠ�ᨨ  �  ᆠ盐盐鼀 �矄 r r E = E ˆ ᆠᨨ矄 wt - kx 㡰   鼀� �ᆠ �  B     鼀ᨨ鼀 t㦨�矄 ᲼㝐� 和 ᔼᔼ㡰桌 r r E 㡰 B = ᆠᨨ矄 kx㡰kˆ  㡰 B = E m e ᆠᨨ矄 kx㡰 ˆ m e 

r r ᆠ㡰 B = E m e ᆠᨨ矄 kx㡰kˆ  㡰 B = 

E m e 

ᆠᨨ矄 kx㡰 ˆ

꾀 ᆠᨨ鼀� �ᆠ犨 矄 ⼄盐 ᆠ泐ᨨ 맔҈҈   �矄 �泐  矄�泐�矄҈맔҈⏌鼀� ᆠ盐盐鼀

鼀�盐 ᨨ  鼀� �ᆠ � ᨨ  犨�矄ᆠᨨ矄ᨨ

Nm  ҈ = 黨 ´҈黨   矄 ᨨ �� 㦨맔҈鼀矄҈㡰 pe C ᲼㝐� 和 ᔼ㡰桌 㡰 ҈�

㡰 ҈

ᆠ㡰 ҈

㡰 ҈黨



WWW.JEEBOOKS.IN

P-239

Electromagnetic Waves

䰘

ᔼ  ᆠᨨ鼀� �ᆠ犨  �ᆠ�ᨨ 矄ᨨ ᆠ�ᆠ �  鼀� �ᆠ � 矄  泐 kˆ   �ˆ -  ˆ 矄ᆠ�泐␔  �矄 盐 �ᆠᨨ ᨨ � �ᆠ�ᨨ  ᨨ ᨨ��ᨨ ᨨ  犨 ᲼㝐� 和 ᔼᔼ㡰桌 㡰

҈ ˆ ˆ � +  㡰 

㡰

҈ 

ˆ + kˆ㡰

҈ ˆ ˆ ҈ ˆ � +  㡰 � +  ˆ 㡰 㡰 � � 꾀 ᆠᨨ鼀� �ᆠ犨�矄ᨨ�� �ᨨ �  �ˆ + ˆ  犨� �矄ᨨ� �ᨨ ᨨ �  �ᆠ�ᨨ

�ᆠ�ᨨ   kˆ  ᆠᨨᆠ ᨨ鼀ᨨ  鼀� �ᆠ � ᨨ  犨 犨ᨨ盐  �矄 ᨨ�ᆠᨨ 矄 㡰 ᲼㝐� 黨  ᔼᔼ㡰桌 æ �ˆ - ˆ �ˆ + ˆ ö ᆠᨨ矄 ç wt - k 㡰  è   ÷ø ᆠ㡰



㡰 

�矄 v kˆ   ᨨᆠᆠ� �ᨨ � 盐ᨨ 犨�矄 ᲼㝐� 䰘  ᔼᔼ㡰桌 �ˆ + ˆ 㡰 ᨨ 㡰 ᨨ  �ˆ + ˆ ᆠ㡰  �ᨨ 㡰 ᨨ kˆ  ҈ 꾀  ᆠᨨ鼀� �ᆠ犨�矄矄  泐 ᆠ�ᆠ ur �  E = E n$ 矄� ᲼w  +  泐 -  㡰桌  ├� �盐 �ᆠᨨ矄�



x, y   z �ᆠ�ᨨ 矄 ᨨ  $�  $  k$    �ᆠ�ᨨ  ᨨ

҈

æ �ˆ + ˆ ö ᆠᨨ矄 ç wt + k è   ÷ø

ˆ - �ˆ

æ �ˆ + ˆ ö ˆ ᆠ㡰  k ᆠᨨ矄 ç wt - k è  ÷ø æ �ˆ + ˆ ö ᆠᨨ矄 ç wt - k è   ÷ø 꾀  ᆠᨨ鼀� �ᆠ犨ᨨ  ⼄盐 ᆠ泐�෌  �矄 ᨨ�� � �  ᆠ盐盐鼀 ᨨ �   z㜠 �ᆠ�ᨨ  꾀  �ᆠ盐ᨨ� � 矄ᆠ �鼀 鼀� �ᆠ � �矄 r ��  泐 B = � ´ ҈- ˆ T     ᆠᨨ矄ᨨ � � ᆠ�ᆠ r �  E �矄 矄 ᨨ �� c㦨´鼀矄㡰 ᲼㝐�   ᔼᔼ㡰桌 㡰 ҈´҈҈ �ˆ ⏌鼀 㡰 ҈´҈҈ �ˆ ⏌鼀

㡰 

黨

҈

�ˆ + ˆ

҈

ᆠ㡰 ҈� �ˆ ⏌鼀 㡰 ҈� �ˆ ⏌鼀 ᔼ  鼀� �ᆠ � �  ᆠᨨ鼀� �ᆠ犨�矄 ur �� 泐 B 㦨´҈矄�  ´҈x졔´҈҈㡰 ˆ  

犨 犨� 矄矄�ᨨ  ᨨᆠ�ᆠ � 䁸 ᲼㝐� 䰘  ᔼ㡰桌 ur  㡰 E 㦨 矄�  ҈´  x 졔´ ҈㡰 kˆ ⏌鼀㡰 ur 㡰 E 㦨 黨矄�  ҈´ x 졔´ ҈㡰 kˆ ⏌鼀㡰 ur ᆠ㡰 E 㦨 ´ 矄�  ´ x졔´ ҈㡰 kˆ ⏌鼀㡰 ur 㡰 E 㦨 ´ 矄�  ´ x 졔´ ҈㡰 kˆ ⏌鼀㡰 ҈҈ ᆠ�ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄 ��  泐 �ˆ + ˆ r E 㦨 E  ᆠᨨ矄 kz + wt 㡰 꾀 t 㦨   ᨨ矄��泐 ᆠ �  �ᆠ �矄    ᨨ� 

pö æ xyz㡰㦨 çè   ÷ø ᔼ �矄� 矄  ᨨ盐矄ᨨᆠ�泐 t 㦨㡰 k

҈�

҈

ᨨᨨ��ᨨ  s$ �矄 ᲼㝐� ҈꾀�҈黨 ᔼ㡰桌 $i -  $j -k$ +  $j 㡰 s$ = 㡰 s$ = � � $j - k$ $ + k$ ö æ   㡰 s$ = ᆠ㡰 s$ = ç ÷÷ ç � � è ø 꾀   ᆠᨨ鼀� �ᆠ 犨 � �  ⼄盐 ᆠ泐 v㦨黨෌ ᨨ�矄ᨨ � ᨨ矄��z㜠 �ᆠ�ᨨ �

矄ᆠ ├盐ᨨ  쟼ᆠ�ᆠ � �矄⏌鼀 ␔ �ᆠ 鼀ᨨ �  ᨨᨨ犨� ��矄 ᆠᆠ鼀� �ᆠ � ᆠᨨ鼀ᨨ  �  ᆠᨨ鼀� �ᆠ犨䁸 ᲼㝐� ҈꾀�҈黨 ᔼᔼ㡰桌 ur 㡰 B =  ´ ҈䰘 矄� � ´ ҈ z + ҈� ´ ҈҈҈ t 㡰$� ur 㡰 B =  ´ ҈-䰘 矄� � ´ ҈ z - ҈� ´ ҈҈҈ t 㡰$� ur ᆠ㡰 B = 矄� � ´ ҈ x + ҈� ´ ҈҈҈ t 㡰 k$ ur -䰘  ҈҈ $ 㡰 B =  ´ ҈ 矄� ҈� ´ ҈ x + � ´ ҈ t 㡰 

ᆠ�ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄��

ur 泐 쟼 = 쟼  $� ᆠᨨ矄 ├ 㡰 ᆠᨨ矄 w 㡰

ᆠᨨ矄ᨨ � �鼀� �ᆠ � �矄  �� 泐 ᲼㝐� ҈꾀�҈黨 ᔼ㡰桌 ur 쟼  $ 矄� ├ 㡰 矄� w 㡰 㡰  = ᔴ ur 쟼  $ 矄� ├ 㡰 ᆠᨨ矄 w 㡰 㡰  = ᔴ ur 쟼  $ ᆠᨨ矄 ├ 㡰 矄� w 㡰 ᆠ㡰  = ᔴ ur 쟼  ├$ 矄� ├ 㡰 ᆠᨨ矄 w 㡰 㡰  = ᔴ ��  �矄 � ᆠ�   ᨨ鼀泐ᨨ   ᆠᨨ鼀泐矄ᨨ� � 矄盐 ᆠ犨�   �泐 盐 ᨨ �␔ᆠ鼀ᔼ  矄盐 ᆠ 矄  ᨨ �ᆠ鼀 鼀ᨨ鼀 盐鼀 矄  ᨨ 矄盐 ᆠ � 鼀� �鼀 盐�ᨨ 犨� ᲼㝐� ҈꾀�҈黨ᔼᔼ桌 㡰 맔҈矄 㡰 ҈맔҈矄 ᆠ㡰 �맔҈矄 㡰 �맔҈矄 꾀 ᆠᨨ鼀� �ᆠ犨ᨨ  ⼄盐 ᆠ泐�㝐 矄 �  矄ᆠᨨ � ᨨ矄��x㜠 �ᆠ�ᨨ 꾀�ᆠ盐 r ᨨ�  �  矄ᆠ   �鼀 쟼 =  ˆ  ⏌ 鼀   r ᆠᨨ矄ᨨ � �鼀� �ᆠ �    ᨨ� 犨� ᲼㝐� 黨꾀�҈黨ᔼ桌  㡰 ҈黨맔҈  ├

ˆ ˆ 㡰 ҈맔҈ ├

  ˆ ˆ ᆠ㡰 맔҈  ├

㡰 ҈黨맔҈  ├

WWW.JEEBOOKS.IN

EBD_8341 P-240

҈䰘

҈

҈黨

Physics

�␔⏌m �泐  矄�泐ᨨ 矄盐 �� �矄 ᨨ鼀泐� ᆠ�   ᨨ   矄盐 ᆠᨨ 矄ᨨ   和ᨨ鼀ᨨ � ᆠ�    �泐 �奠㡰�矄 ᆠ  ᨨ鼀 矄盐 ᆠ  矄�矄 矄ᨨ   ᨨᆠ  ᨨ ҈鼀矄盐 ᆠ犨� ᆠᨨ矄ᨨ ᆠ㦨맔҈鼀⏌矄㡰 ᲼㝐� 黨꾀�҈黨ᔼᔼ桌 㡰 ҈�맔҈ 㡰 맔҈ ᆠ㡰 ҈맔҈ 㡰 �맔҈ 꾀 ᆠᨨ鼀� �ᆠ犨矄�  矄ᆠᨨ � the x㜠 �ᆠ�ᨨ  ᆠ�ᆠ � ᆠᨨ鼀ᨨ  ᨨ  犨 �ᆠ盐ᨨ� ᨨ 矄ᆠ �鼀�矄쟼㦨鼀 ҈ᨨ � y㜠 �ᆠ�ᨨ ᔼ矄ᆠᨨ矄ᨨ � �鼀� �ᆠ � ᆠᨨ鼀ᨨ   犨ᨨ盐  ᲼㝐� 꾀�҈黨ᔼ桌 㡰 맔҈ ᨨ �z㜠 �ᆠ�ᨨ

㡰 맔҈ ᨨ �x㜠 �ᆠ�ᨨ

ᆠ㡰 맔҈ ᨨ �z㜠 �ᆠ�ᨨ

㡰 맔҈ ᨨ �y㜠 �ᆠ�ᨨ

鼀� �ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄�� 泐 ur Wb  = ҈ ´ ҈  ᆠᨨ矄  ´ ҈ 䰘 z +  ´ ҈҈� t �ˆ + ˆ  m

矄矄ᨨᆠ� ᆠ�ᆠ � 犨� ᲼㝐� 꾀�҈黨ᔼᔼ桌

(

)(

)

(

)

V ur 㡰 쟼 㦨맔҈ᆠᨨ矄 맔҈䰘z맔҈҈�t㡰 �ˆ + ˆ m ur V 㡰 쟼 =  ´ ҈  ᆠᨨ矄  ´ ҈ 䰘 z -  ´ ҈҈� t㡰 - $j + $i㡰 m V ur ᆠ㡰 쟼 㦨맔҈ᆠᨨ矄 맔҈䰘z졔맔҈҈�t㡰  �ˆ +  ˆ m V ur 㡰 쟼 㦨맔҈ᆠᨨ矄 맔҈䰘z졔맔҈҈�t㡰 �ˆ   ˆ m

鼀 �  矄�泐ᨨ  ��ᨨ ᨨ  矄盐 ᆠᨨ  和盐

�矄ᨨ盐҈␔⏌鼀 鼀矄盐ᨨ  ᆠᨨ矄ᨨ � � 鼀� �ᆠ � �矄ᆠᨨ矄矄ᨨ ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 ҈

㡰҈

ᆠ㡰 ҈ 㡰 ҈

꾀 ᆠᨨ鼀� �ᆠ犨ᨨ �  矄�泐�␔鼀 矄�  鼀 �盐鼀ᨨ  ᆠ��  � 犨� ᨨ盐 泐ᨨ矄矄 �ᨨ ᨨ  鼀� �盐 矄ᨨ ᆠ�ᆠ � 矄  �ᨨᨨ   鼀� �盐 矄ᨨ 鼀� �ᆠ � 矄ᨨ  犨 ᨨ    � �� ᨨ 鼀 �盐鼀矄ᆠ�泐�� 泐 ᲼㝐�  ҈҈   ҈黨 ᔼ桌 æ ҈ ҈ ö 



㡰 ç 㡰 ÷ è ø ҈ ö æ æ ҈ ö  ÷ ᆠ㡰 ç  㡰 ç ÷

ø è è

ø 꾀䰘鼀␔矄鼀 矄ᆠᨨ矄矄㜠矄ᆠ�ᨨ ᨨ ҈鼀鼀 

 鼀� �盐  ᨨ   鼀 �鼀盐鼀 ᆠ�ᆠ �  �   �矄 ᆠᨨ鼀� �ᆠ犨�矄�� 泐 ᲼෌� 鼀���泐ᨨ 矄ᆠÎ㦨黨맔҈҈和ᔼ盐 �矄和 ᨨ �� ᆠ㦨맔҈鼀⏌矄桌 ᲼㝐� ҈҈ ҈黨ᔼᔼ桌 㡰 ├⏌鼀 ᆠ㡰 䰘├⏌鼀 㡰 ҈├⏌鼀 㡰 ҈├⏌鼀 ᔼ  鼀� �ᆠ � ᨨ  ᆠᨨ鼀� �ᆠ犨�矄 ��  泐  矄 ᨨ ��  㦨 맔 ҈ 鼀⏌矄㡰

(

(



҈

(





)

)

)

é xö ù ҈� æ 㦨҈맔҈矄�  ê  p ´  ´ ҈ çè  - ÷ø ú ᆠ û ë    鼀 �鼀盐鼀ᆠ�ᆠ � 矄矄ᨨᆠ� 犨� ��矄 ᲼㝐�  ҈   ҈黨 ᔼ桌

㡰 맔҈⏌ᔴ 㡰 맔҈⏌ᔴ  ᆠ㡰 맔҈ ⏌ᔴ 㡰 �҈⏌ᔴ  ᆠ�ᆠ �  ᨨ    ᨨ�   ᆠᨨ鼀� �ᆠ 犨�  矄ᆠ�鼀㦨�矄�� 泐  矄矄�ᨨ

ur 쟼 x y 㡰 = ҈ ˆ ᆠᨨ矄 ᲼  xur+  z㡰桌

 鼀� �ᆠ �   x z t 㡰  �矄 ��  泐 ᆠ �矄   ᨨᆠ�泐ᨨ  �� 㡰 ᲼㝐�  ҈   ҈黨 ᔼᔼ桌 ҈ ˆ ˆ ᆠᨨ矄 [  x -  z + ҈ᆠt 㡰 ] 㡰 ├ + �㡰 ᆠ ҈ ˆ ˆ ᆠᨨ矄 [  x +  z - ҈ᆠt 㡰 ] ├ - �㡰 㡰 ᆠ ҈ ˆ ˆ ᆠᨨ矄 [  x +  z - ҈ᆠt 㡰 ] ├ + �㡰 ᆠ㡰 ᆠ ҈ ˆ ˆ ᆠᨨ矄 [  x +  z + ҈ᆠt 㡰 ] ├ - �㡰 㡰 ᆠ � 꾀 쟼㝐犨 ᨨ鼀� 矄鼀 �盐鼀 ᆠ�ᆠ � 矄 r é æ z öù  E҈ = E҈ xˆ ᆠᨨ矄 ê pv ç - t ÷ú � � è c øû ë r E = E xˆ ᆠᨨ矄 [ k  z - ct 㡰]  � 鼀 �盐鼀 犨    犨

盐鼀k  ⼄盐 ᆠ泐v ᨨ �盐矄� �  鼀 �盐鼀�矄 ᨨ 鼀� �ᆠᔼ  Îr҈   Îr  ᨨ�  鼀����矄ᨨ � 鼀 �盐鼀矄ᆠ�泐犨 �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄�矄ᆠᨨᆠ䁸 ᲼㝐� 黨 ҈黨ᔼ桌 Îr Îr ҈ ҈ = = 㡰 㡰 Îr Îr 

ᆠ㡰

Îr Îr

҈



=



҈ 



Îr Îr

҈ 

=

҈ 

  �泐矄矄ᨨᆠ� 犨� ᆠ�ᆠ � �矄 쟼㡰 犨� 鼀� �ᆠ � 矄�矄 㡰 ᨨ ᆠᨨ鼀� �ᆠ犨�

 矄ᆠ    ᲼㝐� 黨  ҈黨 ᔼᔼ桌

 㡰 쟼>  ᆠ㡰 쟼 㡰 쟼㦨 䰘 꾀 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ 鼀 ᨨ  ��  矄  ⼄盐 ᆠ泐  v= ´ ҈҈   �矄ᨨ�� �ᨨ �  �ᆠ�ᨨ

p �ˆ + ˆ ᔼ�矄ᨨ�  ᨨ �  kˆ  �ᆠ�ᨨ  ᆠᆠ  ᨨ鼀 ᨨ 鼀� �ᆠ � �矄 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰  쟼 =

é  æ �ˆ - ˆ ö r E æ �ˆ - ˆ ö ҈ ù 㡰 k  ç ÷ ᆠᨨ矄 ê҈ ç ÷ r -  ´ ҈ 㡰t ú C è  ø êë úû è  ø 㡰

é  æ �ˆ + ˆ ö r E æ �ˆ - ˆ ö ҈ ù ç ÷ ᆠᨨ矄 ê҈ ç ÷ r -  ´҈ 㡰t ú C è  ø êë úû è  ø

ᆠ㡰

é æ �ˆ + ˆ ö r E ˆ ҈ ù k ᆠᨨ矄 ê҈ ç ÷ r +  ´҈ 㡰t ú C è  ø ëê ûú



é æ �ˆ + ˆ ö r E �ˆ + ˆ + kˆ㡰 ҈ ù ᆠᨨ矄 ê҈ ç ÷ r +  ´ ҈ 㡰t ú C  è  ø ëê ûú

WWW.JEEBOOKS.IN

P-241

Electromagnetic Waves



黨

ᆠ�ᆠ � ᆠᨨ鼀ᨨ  ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ  ��ᨨ �矄�� 泐 ur 쟼 㦨쟼 $� ᆠᨨ矄├ ᆠᨨ矄w ur ᔼ矄鼀� �ᆠ �   �矄  �� 泐 ᲼㝐� 졠 � 꾀�黨҈䰘桌 쟼ᨨ $ 쟼  矄� ├ ᆠᨨ矄w 㡰 - ᨨ $ 矄� ├ 矄� w 㡰 ᆠ ᆠ 쟼ᨨ $ 쟼ᨨ $  矄� ├ 矄� w 㡰 ᆠ㡰  ᆠᨨ矄├ ᆠᨨ矄w ᆠ ᆠ ᔴᨨ 矄�  ᆠᨨ鼀� �ᆠ犨ᨨ�� �� ᆠ盐盐鼀 ᔴ ᨨᨨ矄 ᆠᨨᆠ矄鼀  ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ᨨ   ᆠᨨ鼀� �ᆠ 犨 ᨨ�� � �  졔泐 r ҈ �ᆠ�ᨨ  ᆠ�ᆠ � �矄 쟼 = 쟼 泐  㡰 ˆ   r ҈  鼀� �ᆠ � �矄  =   㡰泐ˆ  㡰 ᨨ   ᆠᨨ鼀� �ᆠ 犨 ᨨ�� � �  졔泐 r ҈ 쟼 泐  㡰泐ˆ  �ᆠ�ᨨ  ᆠ�ᆠ � �矄 쟼 =  r ҈  鼀� �ᆠ � �矄  =  泐  㡰 ˆ  ᆠ㡰 ᨨ   ᆠᨨ鼀� �ᆠ 犨 ᨨ�� � �

r ҈ 졔  �ᆠ�ᨨ  ᆠ�ᆠ � �矄 쟼 = 쟼 泐 泐  㡰  ( 泐ˆ + ˆ )   鼀� �ᆠ � �矄 r ҈ = 泐 泐  㡰 ( 泐ˆ + ˆ ) 



҈







㡰 ᨨ   ᆠᨨ鼀� �ᆠ 犨 ᨨ�� � �  졔 r ҈ �ᆠ�ᨨ  ᆠ�ᆠ � �矄 쟼 = 쟼 泐  㡰 ( 泐ˆ - ˆ ) 

r   鼀� �ᆠ � �矄  = ҈  泐  㡰 ( 泐ˆ + ˆ )  ᨨ ᆠᨨ鼀� �ᆠ犨矄ᨨ�� ��   㜠 �ᆠ�ᨨ 犨 �ᆠ ᨨ ᨨ   ᨨᨨ犨� �ᆠᨨ鼀� �ᨨ ��矄 ur ur   ᆠᨨᆠ ᨨ矄矄� �ᆠ�ᨨ  ᨨ 쟼      � 矄ᆠ�泐䁸 ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 㡰 (2$i + 3$j)   ($i + 2$j) 㡰 (-2$i - 3$j)   (3$i - 2 $j) ᆠ㡰 (3$i + 4 $j)   (4$i - 3$j) 㡰 ($i + 2$j)    (2$i - $j) 盐� �  ᨨ��ᨨ  ᨨ  ᆠᨨ鼀� �ᆠ犨矄�   鼀 �盐鼀 ᲼㝐� ҈桌 㡰 쟼ᆠ�ᆠ  �泐  矄�泐�矄 ᨨ盐 ᨨ    鼀� �ᆠ  �泐  矄�泐 㡰 쟼ᆠ�ᆠ �泐  矄�泐�矄  ᨨ  鼀� �ᆠ �泐  矄�泐 ᆠ㡰 쟼ᆠ�ᆠ �泐  矄�泐�矄⼄盐ᨨ 鼀� �ᆠ �泐  矄�泐 㡰 ᨨ ᆠ�ᆠ 鼀� �ᆠ �泐  矄��矄 ᨨ 꾀鼀鼀�矄鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ� �� 盐 � ᨨ鼀泐�  �ᆠ�ᨨ 矄 鼀�矄奠 �ᆠ� � ᆠᨨ � �ᆠ�ᆠ ᨨ犨ᨨᆠᨨ鼀� �ᆠ犨矄 ᆠᨨ 矄盐鼀矄҈␔ᨨ ᨨ犨 鼀�盐 ᨨ  ᆠ�ᆠ � 矄矄ᨨᆠ� 犨�  ᆠᨨ鼀� �ᆠ ��ᨨ  �矄 ᆠᨨ �鼀 ᨨ鼀  ᲼㝐� 졠 � 꾀�҈҈桌 鼀犨� 泐 㡰 ҈⏌鼀 㡰 ⏌鼀 ᆠ㡰 ⏌鼀 㡰 �⏌鼀

鼀� �ᆠ � � � �ᆠᨨ鼀� �ᆠ犨 矄├盐ᨨ 

 ├盐ᨨ ᆠ�ᆠ � 矄 � �矄 ᲼㝐� ҈桌 㡰 ⏌鼀 㡰⏌鼀 ᆠ㡰 黨⏌鼀 㡰 ҈⏌鼀 꾀 ᆠᨨ鼀� �ᆠ犨�  ᨨ 㜠鼀� �ᆠ �ᆠ�ᆠ ur ur 鼀 �盐鼀 �矄 ��  泐 E = E   ´ ҈ -䰘 x - �t 㡰  犨� �矄 ᆠ� �� 鼀 �鼀� 矄ᆠᨨ 矄  �ᆠ�ᆠ ᆠᨨ 矄 ᨨ  鼀 �盐鼀�矄 ᲼㝐� 졠 � 꾀�҈桌 㡰  㡰� ᆠ㡰  㡰 

Topic-2 : Electromagnetic Spectrum 1 ҈





㡰 㡰 ᆠ㡰 㡰

MCQs with One Correct Answer

ᔴ ᨨ矄矄   ᆠᨨᆠ ᨨ�ᨨ  � � 犨 � 矄 ᨨ �  矄ᨨ ᆠᨨ鼀� �ᆠ犨矄ᆠ盐鼀 ᲼㝐� 和 ᔼ㡰桌 㡰 l �矄� < l 鼀�ᆠᨨ犨矄 < l  �ᨨ犨矄 < l X -泐矄 㡰 l  �ᨨ犨矄 > l 鼀�ᆠᨨ犨矄 > l �矄� > l x-泐矄 ᆠ㡰 l x- 泐矄 < l 鼀�ᆠᨨ犨矄 < l  �ᨨ犨矄 < l �矄� 㡰 l �矄� > l x-泐矄 > l  �ᨨ犨矄 > l 鼀�ᆠᨨ犨矄 꾀 �   ᨨᨨ犨� � ᆠᨨ鼀� �ᆠ  ��ᨨ 矄  ⼄盐 盐鼀�  ᨨ ᨨ � ᆠ矄� � �泐᲼㝐� ҈桌 꾀盐��  Ӹᨨ犨��  ᔴ㜠泐   �ᨨ犨 㡰 ᔴ꾀 㡰 꾀ᔴ ᆠ㡰 꾀ᔴ 㡰 꾀ᔴ 㝐�ᆠᨨ犨ᨨ ᆠ矄ᨨ  � ᆠ�ᨨ  ᲼㝐� 졠 � 꾀�黨҈桌



�

��� �ᨨ�ᨨ  �泐ᨨ犨鼀ᨨᆠ盐矄 ��� � 矄�ᨨ  �泐ᨨ犨鼀ᨨᆠ盐矄 ��� ���ᨨ  �泐ᨨ犨鼀ᨨᆠ盐矄  矄 � �ᆠᨨ 矄 ᨨ鼀ᨨ犨 ᨨ ��   �泐 矄� 犨鼀ᨨᆠ盐 ᔼ 鼀�ᆠᨨ犨矄泐矄�  �鼀鼀泐矄盐㜠�ᨨ  �ᨨ 犨矄   �矄� 矄 ᨨ    ᆠᨨ鼀� �ᆠ 矄ᆠ盐鼀  ᨨ 泐㝐ᔼ෌    犨 �ᆠ ᨨ   ᨨᨨ犨� ��矄  �鼀 � 矄ᆠ � �ᨨ ᨨ 犨 � 䁸 ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰 㝐ᔼ ෌ 㡰 㝐 ෌ ᔼ ᆠ㡰 ෌ᔼ㝐  㡰 ᔼ㝐  ෌  ᨨᨨ 矄ᨨ  ᆠᨨ鼀� �ᆠ ��ᨨ  矄  �泐 ҈҈├ᆠ  ᨨ犨 �ᆠ ��ᨨ ᨨ ᆠᨨ鼀� �ᆠ矄ᆠ盐鼀 ᨨ矄�ᨨ �䁸 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 㜠泐��ᨨ

㡰 �ᨨ��ᨨ

ᆠ㡰 ᔼ  ��ᨨ

㡰 �矄���ᨨ

WWW.JEEBOOKS.IN

EBD_8341 P-242

Physics

ᆠᨨᆠ鼀ᆠ 犨   �矄� ᆠᨨ盐鼀 ᔼ ᆠᨨ盐鼀 ᔼᔼ ᲼㝐� 和� ᔼᔼ㡰桌 ᔼ ᔼᔼ  ��ᨨ

W �h 꾀㡰 㝐�ᆠᨨ犨 �㡰 ҈鼀 㡰 ෌鼀鼀泐矄 ��㡰 ҈҈�鼀 ᔴ㡰 꾀㝐 �ᨨ犨矄 ���㡰 ҈҈鼀 㡰 㜠泐矄 �㡰 ҈鼀 㡰 꾀㡰㜠 ��㡰 㡰㜠 �㡰 ᔴ㡰㜠 �㡰 㡰㜠 ���㡰 㡰 꾀㡰㜠 �㡰 㡰㜠 ���㡰 ᔴ㡰㜠 �㡰 㡰㜠 ��㡰 ᆠ㡰 꾀㡰㜠 ���㡰 㡰㜠 ��㡰 ᔴ㡰㜠 �㡰 㡰㜠 �㡰 㡰 꾀㡰㜠 �㡰 㡰㜠 ��㡰 ᔴ㡰㜠 �㡰 㡰㜠 ���㡰 ෌� ᨨ犨�   ᆠᨨ盐鼀  �  鼀ᨨ 矄ᨨ ᆠᨨ鼀鼀盐 �ᆠ�ᨨ  盐矄� � ├� 矄 ᨨ 犨矄��  �    �� ᆠᨨ盐鼀  ᲼㝐� ҈꾀�҈黨ᔼ桌 꾀 졠�ᆠ �  矄ᨨ盐 ᔴᨨ鼀鼀盐 �ᆠ�ᨨ

   턼 ᔼ  ��  ᔴ 和ᨨ   㝐�ᆠᨨ犨矄  㝐ᨨ� ᨨ 矄 和  �ᨨ ␔矄 ᨨ鼀 ᨨ�ᨨ 矄�� ᨨ犨 �  鼀ᨨ矄ᨨ� 鼀ᆠ 犨  �矄�     �� ᆠᨨ盐鼀  㡰 꾀턼和ᔴ  㡰 꾀和턼ᔴ  ᆠ㡰 꾀턼和ᔴ 㡰 꾀 ᔴ和턼 㝐ᆠ �矄㜠ᔼ 쟼ᆠᨨ鼀� �ᆠ犨泐㡰犨� �矄㜠ᔼᔼ ᔼ矄矄矄ᨨᆠ��ᨨ ⏌�ᆠ�ᨨ 㡰 矄ᆠ ᆠᨨᆠᨨ�ᨨ

ᨨ鼀 ᆠ ᨨ�ᆠ矄�� ᨨ犨 �矄矄 ᲼㝐� ҈桌



䰘



�矄҈ ᔼ  犨矄  �ᨨ犨矄 㜠泐矄

�矄 ҈ �㡰 ᨨ鼀盐矄ᆠ盐矄�

 ��㡰 ᨨᨨ ᆠ矄� �  ���㡰 ᨨ ᆠ ᆠ盐ᨨ ᨨ 矄  �ᨨ泐矄 �㡰 꾀矄ᨨ  泐   ᨨ ᨨ 泐ᨨ   鼀ᨨ矄  ҈    㡰 �㡰 ���㡰 ��㡰 �㡰 㡰 �㡰 ��㡰 �㡰 ���㡰 ᆠ㡰 ���㡰 ��㡰 �㡰 �㡰 㡰 �㡰 ��㡰 ���㡰 �㡰 㝐ᆠ    �矄㜠ᔼ   ᨨ鼀 ᨨ  矄矄ᨨᆠ�  犨� ᆠᨨ鼀� �ᆠ  ��ᨨ 㡰 犨�  �矄㜠ᔼᔼ  ᨨ

黨

ᆠᨨ鼀� �ᆠ矄ᆠ盐鼀㡰 矄ᆠ ᆠᨨᆠᆠᨨ  ᨨ鼀  ᆠ ᨨ�ᆠ矄�� ᨨ犨 �矄�矄矄 ᲼㝐� 졠 � 꾀�҈҈҈桌

Match the Following

7

ᔼ ᔼᔼ

�矄ᔼ  ᨨ 盐 ᨨ 矄ᨨ �盐 鼀

�矄ᔼᔼ 꾀 㡰  �矄�   ��ᨨ

␔   �  ᆠᨨ 矄 ᨨ � �  ᨨ   鼀 盐矄矄ᨨ ᆠ�  犨 �   �矄ᨨᨨ  �ᆠ  � �ᨨ  �� �矄ᆠ 

 㡰 㝐 �ᆠ ᨨ犨  

ᔴ 㡰 和 ᨨ  �ᨨ 犨

ᔼᔼᔼ ␔   �  鼀 �  泐 ᨨ 鼀�ᆠ  泐 ᨨ � �  � 矄 矄  ᆠ

ᔼ ␔   �  ᨨ  � �ᨨ   㡰  㜠泐矄 �矄� � ᨨ 鼀犨ᨨᆠᨨ矄  � 泐 矄 �  泐 ᨨ �

㡰 ᔼ㡰㜠 꾀㡰 ᔼᔼ㡰㜠 㡰 ᔼᔼᔼ㡰㜠 㡰 ᔼ㡰㜠 ᔴ㡰 㡰 ᔼ㡰㜠 꾀㡰 ᔼᔼ㡰㜠 㡰 ᔼᔼᔼ㡰㜠 ᔴ㡰 ᔼ㡰㜠 ᔴ㡰 ᆠ㡰 ᔼ㡰㜠 㡰 ᔼᔼ㡰㜠 ᔴ㡰 ᔼᔼᔼ㡰㜠 꾀㡰 ᔼ㡰㜠 㡰 㡰 ᔼ㡰㜠 㡰 ᔼᔼ㡰㜠 꾀㡰 ᔼᔼᔼ㡰㜠 㡰 ᔼ㡰㜠 꾀㡰 ҈ 㝐ᆠ  �矄 ᔼ ␔ �   � ᨨ  ᆠᨨ鼀� �ᆠ 矄ᆠ盐鼀㡰 犨�  �矄 ᔼᔼ 㝐 ᨨ  ᨨ ᨨ 盐ᆠ�ᨨ  ᨨ  矄 犨矄㡰 矄ᆠ ᆠᨨᆠᨨ�ᨨ  ᨨ鼀 ᨨ�ᨨ 矄��

ᨨ犨 �矄矄 ᲼㝐� 졠 � 꾀�黨҈桌 �矄ᔼ

�矄 ᔼᔼ

҈㡰 䰘 鼀ᨨ �㡰 ��ᨨ ᨨ ᨨ鼀矄 ҈鼀鼀  鼀ᨨᆠ盐矄  㡰 ҈ 鼀ᨨ  鼀

��㡰 ᔼ

矄 ᆠᨨ 矄 � ᨨ鼀矄鼀ᨨ� � ᨨ鼀ᨨ  �泐 ᨨ ᨨ犨

㡰 ҈  鼀 ���㡰  �ᨨᆠ� ᆠ泐ᨨ    盐ᆠ盐矄  㡰 ҈鼀鼀ᨨ ҈鼀

㡰 㡰 ᆠ㡰 㡰

�㡰 㝐� ᨨ 

҈㡰㜠 �㡰 㡰㜠 ���㡰 㡰㜠 ��㡰 㡰㜠 �㡰 ҈㡰㜠 ���㡰 㡰㜠 �㡰 㡰㜠 �㡰 㡰㜠 ��㡰 ҈㡰㜠 ��㡰 㡰㜠 ���㡰 㡰㜠 �㡰 㡰㜠 �㡰 ҈㡰㜠 �㡰 㡰㜠 ��㡰 㡰㜠 ���㡰 㡰㜠 �㡰

Answer Key Topic-1 : Electromagnetic Waves, Conduction and Displacement Current ҈ ҈҈ ҈ ҈

㡰 ᆠ㡰 ᆠ㡰 ᆠ㡰

 ҈  

ᆠ㡰 ᆠ㡰 㡰 㡰

 ҈  

㡰 㡰 㡰 㡰

 ҈  

㡰 㡰 㡰 㡰

� ᆠ㡰 ҈� ᆠ㡰 � ᆠ㡰

 㡰 ҈ 㡰  㡰

䰘 㡰 ҈䰘 㡰 䰘 ᆠ㡰

 㡰 ҈ 㡰  ᆠ㡰

黨 㡰 ҈黨 ᆠ㡰 黨 㡰

҈ 㡰  㡰  㡰

 㡰

黨 㡰

҈ 㡰

Topic-2 : Electromagnetic Spectrum ҈

㡰

 ᆠ㡰

 ᆠ㡰

 ᆠ㡰

� 㡰

 㡰

䰘 ᆠ㡰

WWW.JEEBOOKS.IN

P-243

Ray Optics and Optical Instruments

Ray Optics and Optical Instruments

23

Topic-1 : Plane Mirror, Spherical Mirror and Reflection of Light 1

MCQs with One Correct Answer



҈ 졠ᆠ

�  ᆠ鼀㡰





҈

҈





꾀矄 �ᆠ鼀�ᨨ�矄ᨨ�  矄矄 ᨨ犨 �   ��盐 ᨨ鼀  ᨨᨨ犨�矄矄矄 ᔼ  ᨨᆠ�矄ᨨ矄��ᨨ  �  ᨨ ᨨ  鼀�ᨨ犨 犨�  盐 鼀� � �ᆠ�ᨨ ᨨ   �鼀�ᨨ  ᨨᆠ䁸 ��盐 犨 矄矄ᆠ 鼀�ᆠ  ᨨ ᨨ矄ᆠ㡰 [Main Sep.02, 2020 (I)] 㡰 ᔼ   鼀� � � 㡰 쟼ᆠ�盐 鼀� � � ᆠ㡰 쟼ᆠ�盐 盐 鼀� � � 㡰 ᔼ   盐 鼀� � � 꾀ᆠᨨ ᆠ鼀�ᨨ ᨨ ᆠ�犨� � 矄 ᨨᆠ � ᨨ 鼀

 �矄 ᆠ犨 �ᆠ 泐ᨨ盐 ᨨ  鼀�ᨨ ᨨ鼀泐ᨨ盐 ᆠ � ᨨ ᨨ矄泐ᨨ盐�鼀�盐�� 犨� 鼀� � �ᆠ�ᨨ ᨨ ��矄 ᲼㝐� 黨꾀�҈黨ᔼ桌 㡰 鼀 㡰 ҈鼀 ᆠ㡰 鼀 㡰 ҈鼀 꾀ᨨ� 矄ᨨ盐ᆠᨨ �� 和�矄ᆠ  �矄 ᆠ�  ᨨ  ᨨ  ᆠ ᨨ  鼀�ᨨᨨ 犨�   犨 �ᆠ �矄  �� � �ᆠ泐ᨨ 犨꾀鼀 犨├矄�  ᨨ ᨨ  鼀�ᨨ ᨨ �� ᨨ 鼀�ᨨ �矄 ᆠ矄矄 ᨨ犨

ᨨ犨  �矄 ᆠᨨ犨 �ᆠ  鼀 ᆠ 矄 �鼀� ᨨ  �� 矄ᨨ盐ᆠ�  鼀�ᨨ�矄᲼㝐� ҈ ҈黨ᔼ桌 㡰 㡰  和 ᆠ㡰  d  㡰  



犨ᨨ 鼀�ᨨ矄� ᆠ�  ᨨᆠ ᨨ 矄盐ᆠ   泐ᨨ �� � ᆠ�  ᨨ   �矄鼀�ᨨ 㝐҈㡰 ᨨ  矄ᆠᨨ 鼀�ᨨ 㝐㡰�矄 � 泐 ᆠ  ᨨ鼀 矄ᆠᨨ 鼀�ᨨ 㝐㡰ᨨ  �矄鼀�ᨨ 㝐҈㡰  � 犨  犨ᨨ鼀�ᨨ矄犨� ᲼㝐� 黨 ҈黨ᔼᔼ桌 㡰 � 㡰  ᆠ㡰 䰘� 㡰 黨 꾀 ᨨᆠ�矄� 盐泐鼀ᨨ� �犨泐 ᨨ鼀  ᨨᆠᨨ�  ᨨ   ᆠᨨ ᆠ 鼀�ᨨ ᨨ �    �矄 ᨨ    鼀�ᨨ  � �ᆠ 矄 �ᨨ  ᨨ    鼀� �盐  ᨨ  �  鼀� � �ᆠ�ᨨ  m㡰矄盐矄 �矄 ᆠᨨ  ᨨᆠ ᨨ鼀  鼀�ᨨ x㡰�矄ᆠᨨᆠ泐�� 泐 ෌ 矄 犨 矄ᆠ 鼀�ᆠ泐  ᨨᨨ矄ᆠ㡰 ᲼㝐�  ҈黨ᔼᔼ桌

㡰

㡰

ᆠ㡰



꾀�ᆠ�矄ᨨ矄ᆠ�� �ᨨ   㜠 �矄犨�   鼀�盐  ᆠ鼀ᨨ盐 ᨨ� x㦨҈ᆠ鼀犨�  ⼄盐 ᆠ泐w꾀ᆠᨨ ᆠ 鼀�ᨨᨨ  ᨨᆠ � �ᆠ鼀�矄ᆠ  ᨨ���  矄 ��盐㡰 ᔼ  � 泐 ᆠᨨᆠ矄鼀 矄 ᲼㝐� 졠 � 꾀�҈�҈桌 꾀㡰 �鼀� ᆠ盐矄�ᨨ �ᆠ鼀ᨨ�ᨨ

㡰 �鼀� ᆠ盐矄 ᨨ 㜠�ᨨ �ᆠ鼀ᨨ�ᨨ

ᔴ㡰 盐 � �ᨨ� 矄ᨨ  �鼀�矄泐鼀鼀�ᆠ犨  �鼀�ᨨ  ᨨ� x㦨҈ᆠ鼀 㡰  �矄 ᆠ 犨    盐 � � ᨨ� 矄 ᨨ    ҈ x㦨҈ᆠ鼀 ᨨ矄ᆠ��ᨨ ᨨ  �鼀��矄 ҈ x㦨 㡰 㡰 㡰 㡰 㡰 ᔴ㡰 ᆠ㡰 꾀㡰 ᔴ㡰 㡰 㡰 꾀㡰 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-244

Physics

Ӹᨨ盐矄├ ᨨ 矄�� 矄 � �鼀�ᨨ矄矄盐鼀� �  矄ᨨ ├矄�҈ᆠ鼀 ᨨ鼀 �矄 ᆠ �犨矄 鼀� � � �鼀�ᨨ   ᆠ  ᆠᨨ矄矄 ᆠᨨ鼀 ᨨ �矄 ᆠᨨ �ᆠ鼀  �盐矄ᨨ ᆠ盐盐ᨨ  鼀�ᨨ犨ᨨ盐    ᲼㝐� 졠 � 꾀�҈҈�桌 㡰 ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ᆠ鼀 ҈  꾀泐ᨨ �� � ��   �ᆠ�ᨨ  �ˆ +  ˆ 㡰 �矄� ᆠ�    ᨨ  鼀�ᨨ꾀  ᆠ�ᨨ �矄ᨨ �  �ᆠ�ᨨ

҈ ˆ � -  ˆ 㡰   �ᨨ � ᆠ�  ᆠ�矄 ᲼꾀 ҈桌  㡰  ᆠ㡰  㡰 � 㡰 䰘� 黨 ᔼ     �鼀  ᨨ 鼀�    ᨨᆠ  � f 㡰ᨨ ᆠᨨ ᆠ鼀�ᨨ泐 盐㜠鼀 ᨨ 矄盐  ᆠ矄  ᨨᆠ� 꾀ᨨ  � ᆠ� �矄 �矄 ᆠ  ᨨ鼀  ᨨP 矄盐  ᨨᨨ├矄 �  �矄�  �鼀� ᨨ鼀 �矄 ᆠ├� � �矄⏌ 泐� � 犨� PA␔ 

 矄盐  矄 � 矄 �矄⏌ 泐ᨨ犨 矄  �鼀�矄 ᨨ �� ᨨ  ᨨᆠ�   ᲼䰘桌 㡰 xf 㡰 fxf ᆠ㡰 x㦨f 㡰 x>f ҈ 꾀ᨨ� 矄ᨨ盐ᆠᨨ �� B�矄ᆠ  B �矄 ᆠL�  ᨨ ᨨ  ᆠ ᨨ  d 鼀�ᨨᨨ 犨�  ἘdἘ 盐 ��ᆠ泐ᨨ  犨꾀鼀 犨├矄�  ᨨ ᨨ  鼀�ᨨ L ᨨ �� ᨨ 鼀�ᨨ 2L �矄 ᆠL ᨨ鼀�矄矄 ᨨ犨 �  ��  �矄 �矄 ᆠᨨ犨 �ᆠ  ᆠ 矄 �鼀�ᨨ   �� 矄ᨨ盐ᆠ�  鼀�ᨨ�矄 ᲼和桌 㡰 d⏌ 㡰 d ᆠ㡰 d 㡰 d ҈҈ 꾀矄 ᨨ� ᨨᆠᨨ  � �矄ᨨ �  �矄ᨨ  ᆠᨨ ᆠ鼀�ᨨᨨ  ᨨᆠ �   �矄 盐 ᨨ鼀  ᨨᨨ  鼀�ᨨ 矄� ᨨ  �鼀��矄ᨨ �鼀泐 ⼄盐ᨨ ᲼҈黨㜠㝐├桌 䰘

㡰

æu - f ö bç è f ÷ø

ᆠ㡰

æu- f ö bç è f ÷ø

2 ҈

æ f ö bç è u - f ø÷





Integer Value Answer

ᔼ鼀�ᨨ  ᨨᆠᨨᆠ � �ᆠᨨ  鼀�ᨨᨨ  �盐矄 ᨨ ᆠ盐盐  鼀 ᨨ � �矄ᨨ�ᆠ  �矄�矄ᨨ矄  ᨨ � � 鼀ᨨ ᨨ鼀 鼀 ᨨ 鼀� 矄ᆠᨨ 矄␔ �矄 矄  䰘 ᨨ  ᨨᆠ� ├鼀 ᨨ盐䁸 ᲼҈桌 3

҈

æ f ö bç è u - f ø÷

҈⏌ 

㡰

҈⏌ 

Numeric Answer

␔   ᨨᆠ�矄├ �矄 ᆠᨨ ᆠ鼀 ᨨ鼀ᆠᨨ ᆠ 鼀�ᨨ �鼀��矄 ᨨ鼀  �矄 ᆠᨨ ҈ᆠ鼀 ᨨ鼀  鼀�ᨨ ᔼ    ᨨᆠ �矄 鼀ᨨ  犨�   矄  ᨨ  黨 ᆠ鼀矄҈ 矄  � ᆠ鼀矄҈㡰犨� 犨 �ᆠ �鼀�鼀ᨨ矄  � 矄 �矄힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌

4

Fill in the Blanks

f ҈ 꾀 � ᨨ ᨨ  �  �矄ᆠ ᨨ � ᨨ�ᆠ �矄ᨨ   ᆠᨨ ᆠ鼀�ᨨᨨ  ᨨᆠ �  矄盐ᆠ  �矄�鼀�犨 �ᆠ �矄    ᨨ �  盐矄 ᨨ盐ᆠ 矄   ᨨ   鼀� � �ᆠ�ᨨ �矄 ᲼҈黨黨҈㜠҈㝐├桌

6

MCQs with One or More than One Correct Answer

҈� 꾀犨��矄 �  矄 ᨨ ��  � � � �矄 ᆠ �  ᨨ ᨨ ᆠᨨ ᆠ鼀�ᨨᨨ  ᨨᆠ �  f矄 矄 ᨨ犨 �   ��盐␔ �ᆠ ᨨ   ��盐矄矄 ᨨ犨 �   ᨨ盐ᨨ�ᨨ 矄⼄盐��泐矄  矄㡰 矄 ᨨ   �鼀�ᨨ   犨�䁸 矄 ��盐矄 ᨨᨨ矄ᆠ㡰 ᲼꾀 ҈桌



� f 

f

¥

㡰

a

ᨨ a >�

㡰

¥

ᆠ㡰

a

ᨨ a � 㡰

҈ 꾀矄盐   ᨨ鼀   �鼀 ᨨ  鼀� �ᨨ ᨨ ᨨᆠ � ᨨ ᆠᨨ ᆠ鼀�ᨨ泐u㜠v 鼀 ᨨ 盐矄� �

ᨨ�ᆠ ᆠ ᨨ  � ҈�鼀  ᨨᆠ � ᨨ   鼀�ᨨ盐矄 �矄ᆠ鼀 鼀 �鼀盐鼀ᨨ�  ᨨᆠ�ᨨ ᨨ  �鼀�ᆠ ᆠ鼀 �矄矄ᨨ  u, v 㡰盐矄ᆠᨨ  泐 矄盐   � ᆠ鼀㡰 �㡰 㡰 㡰 㡰 䰘黨㡰  矄 矄㡰  ᆠ

ᨨᆠᨨ鼀 ᨨ鼀 �鼀  �矄 㡰� ᆠᨨᆠ泐 ᆠᨨ  �矄 㡰 ᲼黨桌 㡰 �㡰 㡰 㡰 ᆠ㡰 㡰 㡰 䰘黨㡰 9

Assertion and Reason Type Questions

҈䰘 和T꾀TE㝐ENT㜠҈  ᨨ鼀盐ᆠᨨ

ᆠ� �uv f ᨨ 矄 �ᆠ鼀�ᨨ�矄�  ᨨ鼀�ᨨ矄犨 ᨨ矄矄� 矄泐 矄鼀ᆠᨨ鼀 ᨨ � ��ᨨ ᆠ盐盐 和T꾀TE㝐ENT㜠犨矄ᨨ  ᆠ�ᨨ 矄�ᆠ泐�  ᨨ  矄盐 ᆠ矄盐 ᨨ ᨨ�矄 �ᆠ矄盐 ᆠ矄 ᲼䰘桌 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐

WWW.JEEBOOKS.IN

P-245

Ray Optics and Optical Instruments

Topic-2 : Refraction of Light at Plane Surface and Total Internal Reflection 1 ҈

MCQs with One Correct Answer

꾀矄矄ᨨ    �矄   � 犨� �⼄盐� ᨨ  ᆠ� �         盐   犨�  ᨨ  �⼄盐� ᨨ  ᆠ� �     �⼄盐� 矄  �鼀鼀�矄ᆠ�     ᨨ  �

矄盐 ᆠᨨ  ᨨᨨ鼀ᨨ 矄矄 犨� ᲼㝐� 黨 ᔼ桌 h h 㡰 㡰   + ҈㡰 

h







 h  ᆠ㡰 㡰   

�矄矄鼀矄ᨨ盐ᆠᨨ �� 矄ᨨ鼀  ᨨ犨   矄盐 ᆠᨨ 犨  ᆠ��  㦨 㡰�  ├ᨨ �  ᆠᨨ矄矄 矄ᆠ�ᨨ  矄盐 ᆠ  �ᆠ� �  泐 ᆠ�ᨨ

ᨨ鼀 ᨨᨨ鼀 矄ᨨ�ᨨ 泐犨ᆠ �ᨨ ��  鼀�矄ᨨ盐ᨨ 矄盐 ᆠ�矄 泐㡰 ᲼矄  ᆠ 矄盐 ᆠᨨ 矄 �ᆠᆠᨨ  ��  h  �盐矄ᨨ ᆠ盐盐r�矄prh桌᲼㝐� 黨 ᔼᔼ桌 㡰 ҈奠 㡰 奠 ᆠ㡰 ҈䰘奠 㡰 �奠

ᆠ��ᆠ �ᨨ 鼀 �盐鼀 ᨨ矄ᆠ� �ᆠ犨 � �   鼀 �盐鼀 矄 � 鼀���泐    �

 鼀��泐 ᨨ �矄犨 � 犨�  ᲼㝐�  ᔼ桌 㡰 ҈� 㡰  ᆠ㡰 � 㡰  꾀  矄  ᆠ盐 ᨨ  矄�   鼀  ᨨ   鼀� ᨨ  ᆠ��  m�矄�鼀鼀矄 � �⼄盐� ᨨ  ᆠ� �  m҈ m҈ m㡰꾀泐�矄� ᆠ�  ᨨ   ᆠ꾀

 �q 矄 ᨨ犨 �   ��盐㡰 ᨨ�   ᆠ�ᨨ ├矄 ᆠᨨ� 쟼ᨨ   ᆠᔴ



䰘



㡰

  +  

ᆠ㡰

 +

�

㡰

q < 矄� -҈

ᆠ㡰

q < 矄� -҈

m҈ m m  m҈



᲼㝐� ҈꾀҈黨ᔼᔼ桌 㡰

q > 矄� -҈



q > 矄� -҈

m  m҈



m҈ m

꾀泐ᨨ �� 꾀졠� ᆠ盐盐鼀�矄� ᆠ�  ᨨ �矄矄矄  �ᨨ  ᆠ  �ᨨᨨ �졠矄矄 ᨨ犨

�   ��盐 ᨨ�ᆠ  � ᨨ �� 泐 ᨨ鼀꾀ᨨ �矄 ᲼㝐� ҈꾀҈黨ᔼ桌

 +

 



㡰 졔  ᔼ  ��盐 ᨨ�ᆠ ��矄l㦨鼀ᨨ �  矄 �鼀 ᨨ d㦨m鼀ᔼ 泐ᨨ �� �矄� ᆠ�  ᨨ ᨨ  ᨨ   � �q҈㦨   盐鼀ᨨ  ᆠ�ᨨ 矄�鼀├矄  ᨨ鼀�� � ᨨ鼀 ᨨ  �矄ᆠᨨ矄ᨨ  ᆠ��  ᨨ  ��矄҈҈ 矄�  㦨㡰 ᲼㝐� 꾀�҈黨ᔼ桌

㡰 �� 㡰  ᆠ㡰 � 㡰 �䰘 꾀 ��  犨 �矄 � ᆠ�   ᨨ鼀泐 ᨨ   �矄矄 矄 ᨨ  ᆠ��  ҈�ᔼ 奠ᨨ �� �矄 ᆠ    鼀�盐 ᨨ  ᆠ�ᆠ � ᨨ  � ᆠ�  �� �矄⏌ 鼀   鼀�盐 ᨨ  ᆠ�ᆠ �  ᨨ 犨 ᨨᨨ�� ��  �矄矄鼀 �盐鼀犨� ᲼㝐� ҈ ҈黨ᔼ桌 㡰 ⏌鼀 㡰 ҈⏌鼀 ᆠ㡰 ⏌鼀 㡰 ⏌鼀   ᆠ��  ᨨ   矄鼀 �盐鼀犨� 矄ᆠᨨ 鼀 �盐鼀 ҈ �矄ᆠ��ᆠ �qᔴ꾀

 �ᨨ � ᆠ�  ᆠ꾀犨  �� �矄� � ᨨ鼀  矄 鼀 �盐鼀ᨨ鼀 �盐鼀ᨨ  �� �矄 ᆠ   矄�矄 ᆠ    �犨  ᆠ   ᆠ 泐矄�矄黨 꾀 �꾀�矄�� 泐 ᲼㝐� 졠 � 꾀�҈䰘桌 㡰

 q鼀盐矄矄�矄 泐

㡰

҈ -҈

ᆠᨨ矄 矄� qᔴ 㡰

㡰

҈ -҈

 矄� qᔴ 㡰

ᆠᨨ矄҈ 矄� q

黨

ᆠ㡰 㡰  ҈ 矄� qᔴ㡰 ᔴ㡰 꾀 � ᨨᨨ├� � 盐  ᨨ盐�   犨 矄矄  ᨨ盐矄�  犨ᨨ ᆠᨨ �  � ᆠ�ᆠ盐 ᨨ� ᨨ   ᆠ��   ᨨ 犨�矄    �矄泐矄҈�ᆠ鼀ᨨ犨   矄盐 ᆠᨨ 犨    �盐矄ᨨ  ᆠ�ᆠ�矄 ᲼㝐� 졠 � 꾀�黨҈桌 㡰

҈� ´  ´ � ᆠ鼀

㡰 ҈� ´  䰘 ᆠ鼀

ᆠ㡰

҈� ´ 䰘 ᆠ鼀 



҈� ´  䰘

ᆠ鼀

WWW.JEEBOOKS.IN

EBD_8341 P-246

10.

Physics

A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the liquid is [Adv. 2014]

Liquid

Block

11.

S (a) 1. 21 (b) 1. 30 (c) 1. 36 (d) 1. 42 A light ray falls on a square glass slab as shown in the diagram. The index of refraction of the glass, if total internal reflection is to occur at the vertical face, is equal to : [Main Online April 23, 2013]

Air r Water

r

Glass

i

(a) (4/3)sini (b) 1/sini (c) 4/3 (d) 1 16. Two plane mirrors A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle 30° at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before it emerges out is [2002S] B

2 3m

0.2m 30°

45° Incident ray

A

(a) 28 (b) 30 (c) 32 (d) 34 17. An observer can see through a pin-hole the top end of a thin rod of height h, placed as shown in the figure. The beaker height is 3h and its radius h. When the beaker is filled with a liquid up to a height 2h, he can see the lower end of the rod. Then the refractive index of the liquid is [2002S] 5 3 3 ( 2 + 1) (b) (c) (d) 2 2 2 2 A ball is dropped from a height of 20 m above the surface of water in a lake. The refractive index of water is 4.3. A fish inside the lake, in the line of fall of the ball, is looking at the ball. At an instant, when the ball is 12.8 m above the water surface, the fish sees the speed of ball as [Take g = 10 m/s2.] [2009] (a) 9 m/s (b) 12 m/s (c) 16 m/s (d) 21.33 m/s A ray of light traveling in water is incident on its surface open to air. The angle of incidence is q, which is less than the critical angle. Then there will be [2007] (a) only a reflected ray and no refracted ray (b) only a refracted ray and no reflected ray (c) a reflected ray and a refracted ray and the angle between them would be less than 180° – 2q (d) a reflected ray and a refracted ray and the angle between them would be greater than 180° – 2q A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of virtual image from the surface is [2004S] (a) 6 cm (b) 4 cm (c) 12 cm (d) 9 cm A ray of light is incident at the glass-water interface at an angle i, it emerges finally parallel to the surface of water, then the value of m g would be [2003S]

(a)

12.

13.

14.

15.

3h h

2h

5 3 5 3 (b) (c) (d) 2 2 2 2 18. A ray of light passes through four transparent media with refractive indices m1, m2, m3 and m4 as shown in the figure. The surfaces of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have [2001S] (a)

m1

m2

D

m3

m4

C B

A

(a) m1 = m2 (c) m3 = m4

(b) m2 = m3 (d) m4 = m1

WWW.JEEBOOKS.IN

P-247

Ray Optics and Optical Instruments

҈黨

꾀ᆠ �盐�矄矄矄ABCDᨨ  ᆠ��  n҈�矄 �鼀鼀矄 � 犨ᨨ  ᆠ��  n n҈>n㡰꾀泐ᨨ �� �矄� ᆠ�   矄盐 ᆠABᨨ  矄矄矄 ᨨ犨 

鼀 �鼀盐鼀盐ᨨ   �ᨨ � ᆠ�  ᆠa鼀 矄盐ᆠ   泐ᆠᨨ鼀矄ᨨ盐ᨨ 泐 ᨨ鼀 ᨨ 矄盐 ᆠCD�矄 ��  泐 ᲼和桌 꾀



㡰



én æ æ n ööù 矄� -҈ ê ҈ ᆠᨨ矄 ç 矄� -҈ ç  ÷ ÷ ú è n҈ ø ø úû è êë n

é æ æ ҈ öö ù 㡰 矄� -҈ ên҈ ᆠᨨ矄 ç 矄� -҈ çè n ÷ø ÷ ú è êë  ø úû ᆠ㡰 

æn ö 矄� -҈ ç ҈ ÷ è n ø

鼀 鼀D

鼀҈  鼀҈㡰D

æn ö 矄� -҈ ç  ÷ è n҈ ø



꾀 ��� �鼀ᨨ ��  ᨨ鼀ᨨ� 矄ᨨ盐ᆠS � � �� ᆠ � a  矄矄泐鼀鼀�ᆠ泐ᨨ �矄矄矄矄 矄 ᨨ犨   �矄ᨨ � ᆠ�  ᆠᨨ  犨ᨨ 鼀泐矄 ⼄盐ᔼ   �ᆠ├ 矄矄ᨨ  �矄矄矄�矄t    ᆠ��  n    �� ᆠ �ᨨ  鼀�  鼀�矄 ᲼和桌 S i

a

i

m

㡰 ᨨ ᆠ㡰 ҈

æ ҈ö 矄� -҈ ç ÷ è nø

t

㡰

a



æ ҈ö 矄� -҈ ç ÷ è nø

꾀泐ᨨ ��  ᨨ鼀  矄鼀 �盐鼀矄�├鼀 �盐鼀     � ᨨ � ᆠ�  ᆠ � 矄 ��㡰   ᆠ    ᆠ 泐矄鼀├  �ᨨ 黨 犨� ᆠ ᨨ    �矄ᨨ  ᆠ�ᨨ   ᆠ�ᨨ r  r ᆠ��ᆠ  ��矄 ᲼҈黨㜠҈㝐├桌

i

Integer Value Answer

2

 꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� �矄� �� 鼀 �盐鼀ᨨ  ᆠ� �   㦨҈ᔼ 矄矄ᆠ├ᨨ �矄矄泐矄 ᨨ鼀  ᨨᨨ鼀矄�   �q㦨  �  ᆠ矄ᨨ  �矄矄 泐矄ᨨᆠ ᨨ   ᆠ�� �ᆠ矄ᨨ �  �矄矄泐矄鼀ᨨ ᨨᨨ �ᆠ泐 ᆠ矄� �矄 鼀㦨

鼀D 犨  鼀�矄  ᆠ��  ᨨ  鼀 矄 D 㦨҈ 矄  ��盐㡰 泐�矄 ᆠ ᨨ盐ᨨ  �  ᆠ犨   鼀҈㡰  鼀 矄矄 ᨨ鼀  �� 矄� ᨨ  矄ᆠ├␔ �矄 盐ᨨ 鼀䁸᲼꾀 ҈䰘桌





҈

a鼀

 ␔  泐ᨨ ��  矄�矄矄矄 ᨨ鼀� ᲼҈黨桌 㡰 �矄犨 �  ᆠ矄矄 㡰 �矄犨 � � ᆠ矄矄 ᆠ㡰 ᔼ矄 ⼄盐 ᆠ泐 ᆠ矄矄 㡰 � �矄犨 �  ᨨ�矄 ⼄盐 ᆠ泐ᆠ  �矄

r

  ҈

q

  ␔ 犨�  ᆠ��  㦨 㡰�  ├�矄҈ᆠ鼀   䰘 졠�ᨨ  ᆠ��   �矄ᨨ 犨鼀├� �ᆠᨨ   矄盐 ᆠᨨ  �盐矄ᨨ ᆠ盐盐� 㦨ᆠ鼀矄矄 ᨨ犨 ᔴᨨ 矄�  ᨨ�ᨨᆠ矄 �  矄꾀 ᨨᆠ�和�矄ᆠ ᆠ鼀ᨨ 犨矄盐 ᆠ ᨨᆠ�ᨨ ᨨ �矄�鼀��矄� ᆠ鼀ᨨ  ᨨᨨ鼀ᨨ   ├  � �矄 ᲼҈҈桌

� 꾀��矄矄矄 m = � ⏌ 㡰 ᨨ  �ᆠ├ 矄矄ᆠ鼀�矄ᆠ ᨨᨨ� 矄ᨨ盐ᆠᨨ �� ᨨ  矄盐 ᆠᔼ�矄矄

 �� 鼀�矄ᨨ盐ᨨ  ᨨ矄盐 ᆠᨨ  矄 ᨨ鼀 ᆠ�ᆠ盐ᨨ  �盐矄 ᆠ鼀␔ �矄 盐ᨨ  䁸᲼҈桌 3

rἘ 㡰

sin –҈ tan r 㡰

㡰

sin –҈ tan i 㡰

ᆠ㡰

sin –҈ tan rἘ㡰



 ҈ 矄� � 㡰

D

D

D



Numeric Answer

 꾀 ᨨ矄ᆠ 矄 ᨨ盐� 矄鼀 ᨨᨨ  矄� ᨨ    �盐矄҈�ᆠ鼀㡰ᨨ�  �� ᨨ ҈�ᆠ鼀 ᨨ鼀  ᨨᨨ鼀 矄 ��盐㡰  ᨨ�矄 �� ᨨ �ᆠ鼀␔ 

 �矄 � 犨� �⼄盐� 盐ᨨ �� ᨨ ᆠ鼀 矄鼀 ᨨ矄ᆠ 矄  � ᨨᨨ鼀ᨨ  ᔼ    ᆠ��  ᨨ  �⼄盐� �矄N⏌҈犨 N�矄 � �  盐ᨨ N�矄힘힘힘힘힘힘힘힘힘힘힘 [Main Sep. 03, 2020 (I)]

WWW.JEEBOOKS.IN

EBD_8341 P-248

Physics

�ᆠ鼀 ҈�ᆠ鼀

҈�ᆠ鼀

䰘



黨 

҈



꾀�� 泐 矄矄ᨨ� �矄矄矄 ᨨ  ᆠ��  m =      � ᨨ � ᆠ�  ᆠ     泐 �矄 ᨨ  ᆠ   ᆠ    矄盐 ᆠᨨ  矄 

 � �  �矄㡰犨   ᆠ   ᆠ 泐矄 �矄矄盐 ᆠ�矄힘힘힘힘힘힘힘힘힘힘힘 [Main Sep.02, 2020 (II)] 꾀 矄盐ᆠ盐ᨨ  � L 犨�  W�矄鼀 ᨨ 犨ᨨ �  ᨨ�ᆠ鼀 �ᨨ  ᆠ�� �ᆠ矄n҈㦨҈� n 㦨҈矄矄 ᨨ犨 �  ��盐ᔼ L>>W泐 � � ᨨ鼀 꾀犨�鼀� ᨨ鼀 ᔴᨨ 泐�  ᨨ�    ᆠ�ᨨ ᆠᨨ ��ᨨ �矄鼀� 矄�  矄盐ᆠ盐 ᨨL㦨黨m �  � ᆠ�   �q�矄�  鼀 �鼀盐鼀�鼀├

泐泐ᨨ �  ᔴ�矄t맔҈㜠黨s犨 t�矄힘힘힘힘힘 ᲼꾀 ҈黨桌

4 Fill in the Blanks 꾀�� ᨨ 犨 � 处� � 矄鼀 �盐鼀犨�  ᆠ��  ҈�ᔼ 矄�  鼀 �盐鼀�矄 ⼄盐 ᆠ泐�矄   �矄犨 � �矄处 ᲼҈黨黨䰘㜠㝐├矄桌 꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ鼀ᨨ �� ᨨ 犨 � 处�

ᆠ盐盐鼀 矄鼀 �盐鼀ᨨ  ᆠ��  ҈�ᔼ   鼀 �盐鼀�矄犨 � �矄�矄 ⼄盐 ᆠ泐�矄 ᲼҈黨�㜠㝐├矄桌 꾀�� 犨ᨨ  ⼄盐 ᆠ泐�맔҈҈  矄鼀 �盐鼀ᨨ  ᆠ��  ҈�ᔼ  鼀 �盐鼀 ᨨᆠ�泐ᨨ  ��  犨�矄 �矄犨 � �矄᲼҈黨㜠㝐├矄桌 6 MCQs with One or More than One Correct Answer 꾀 矄 矄ᨨ  �ᆠ├ 矄矄  矄 ᆠ��   㡰  � ᆠ矄矄犨�   �矄 �ᆠ �矄 ᆠ� 矄�   矄鼀矄盐  ᨨ鼀 ᨨ 矄�矄ᆠ 犨

犨ᨨ鼀 �犨� 盐 � ᨨ鼀 ᆠ�� �ᆠ矄 ҈   > ҈㡰 矄矄 ᨨ犨 �   ��盐꾀泐ᨨ �� �矄� ᆠ�  犨�  � q� ᨨ鼀鼀 �盐鼀҈ 鼀�矄� 鼀 �盐鼀犨�  ᆠ�ᨨ

᲼꾀 ҈桌  �q犨�  �矄ᆠ鼀 l

␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 㡰 矄� q�㦨 矄� q 㡰 ҈矄� q�㦨  ҈㡰矄� q ᆠ㡰 l�矄�   ᨨ   㡰 l�矄   ᨨ  㡰  꾀泐ᨨ �� � ��  矄 鼀 �盐鼀 矄ᨨ  矄盐 ᆠ矄� � 鼀 �盐鼀 ᨨ鼀�  �ᨨ � ᆠ�  ᆠ ᨨ �  泐盐 �ᨨ矄ᨨ�   ᆠ�ᨨ ᔼ n �矄   ᆠ��  ᨨ  鼀 �盐鼀犨� 矄ᆠᨨ�矄ᆠ  ᨨ矄矄�盐 矄㡰ᨨ   ᨨ鼀  ᨨᨨ犨� �᲼҈黨黨㜠㝐├矄桌 㡰 ҈ 㡰 ҈ ᆠ㡰 ҈� 㡰 ҈ Comprehension/Passage Based Questions 矄矄� �� �盐�  ᆠ�  ᨨ�ᆠ �ᆠ 盐 矄ᨨᨨ 泐 ᆠᨨ 矄� � �  矄盐ᆠ盐 ᆠᨨ鼀�矄� � ᨨ   �  矄ᨨ�  �矄矄 ᆠ泐� ᨨ  ᆠ��  n҈矄盐ᨨ盐  泐鼀 �盐鼀ᨨ ᨨ犨  ᆠ� �   n  ��  �盐�  ᆠ �    矄盐ᆠ盐 ├矄 ᆠ 盐 ᨨ 矄盐ᆠᆠ矄矄� ᨨ �    ᆠ�ᨨ 矄 �  ᆠᨨ  鼀 �n҈ n矄矄 ᨨ犨

�   ��盐꾀泐矄犨�   �ᨨ � ᆠ�  ᆠ�矄矄   �ᆠ盐盐�mᆠᨨ �  �  鼀 �盐鼀ᨨ  ᆠ��  n҈  盐鼀�ᆠ盐 꾀㡰ᨨ   矄盐ᆠ盐�矄  �  矄s�n�鼀 8

 ᨨ犨ᨨ矄盐ᆠ盐 鼀泐S҈犨�  n҈ = � ⏌   n㦨⏌  S犨� n҈㦨⏌� n㦨䰘⏌� ├� �  ᆠ� �  ᨨ 犨ᨨ⏌  ᨨ �ᨨ҈ ᆠᨨᆠ ᨨ�ᨨ 矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 NAᨨ S҈�鼀鼀矄 � 犨�矄 矄鼀矄 ᨨ S ҈ �鼀鼀矄 � �⼄盐� ᨨ  ᆠ��    ҈�  㡰 NAᨨ S҈�鼀鼀矄 � �⼄盐� ᨨ  ᆠ��   �矄 ҈�  矄鼀矄 ᨨ S�鼀鼀矄 � 犨 ᆠ㡰 NA ᨨ  S҈ ᆠ � � �矄   矄鼀 矄   ᨨ S  �鼀鼀矄 � �⼄盐� ᨨ  ᆠ��   ҈� 㡰 NAᨨ S҈ᆠ � ��矄 矄鼀矄 ᨨ Sᆠ � 犨 � ᔼ 犨ᨨ矄盐ᆠ盐ᨨ 矄鼀ᆠᨨ矄矄㜠矄ᆠ�ᨨ 盐 �  

盐鼀�ᆠ盐矄NA҈ NA NA2NA1㡰ᨨ�  ᨨ ��盐 � 泐  盐鼀�ᆠ盐ᨨ  ᆠᨨ鼀�  矄盐ᆠ盐�矄 ᲼꾀 ҈�桌 㡰

NA҈ NA NA҈ + NA

ᆠ㡰 NA ҈

㡰 NA҈졔NA 㡰 NA 

WWW.JEEBOOKS.IN

P-249

Ray Optics and Optical Instruments

10 Subjective Problems 

꾀⼄盐ᆠ泐� ᨨ  �盐矄R  ᆠ��  ҈��矄 ᆠ ᨨ 꾀ᨨ� ᨨᆠ�矄├ �矄 ᆠᨨ mR ᨨ鼀� �  盐ᨨ m ᨨ犨 �ᆠ 泐 ᨨ鼀P犨� 鼀�ᨨ 矄矄 ᨨ犨 �  ��盐 ᲼҈黨黨黨㜠�㝐├矄桌

黨 꾀鼀ᨨ �� � �� 犨  ᆠ��  㦨⏌㡰�矄 ᆠ 泐矄 �ᆠ�盐ᨨ  �盐矄鼀鼀 矄�盐 � 犨꾀矄矄盐鼀� � �� 泐矄ᨨ � ᲼҈黨㜠㝐├矄桌 �㡰 �  ᨨ矄��ᨨ ᨨ  �鼀� 盐ᨨ ᆠ�ᨨ   �矄矄盐 ᆠ  ᨨ矄��ᨨ ᨨ   � �鼀� ��㡰 犨泐 ��鼀矄 ᨨ犨� � ᨨ矄��ᨨ 矄ᨨ ᨨ  �鼀�矄  꾀�� �矄鼀�矄ᨨ鼀 泐矄ᆠ� �ᨨ鼀�    �矄A B B £ A㡰 矄矄 ᨨ犨 �  ��盐ᔼ�矄 矄�  泐ᨨ �� � ᆠ�  ᨨ   ᆠ꾀鼀�矄  ᨨ   � ᆠ�   �ᆠ�ᨨ    犨ᨨ �    ᆠ�ᨨ 矄

 䰘





xy �矄 ᨨ盐 泐犨 犨ᨨ 矄  鼀 �㝐 �盐鼀҈犨�  z ³   矄 ᆠ��   2  鼀 �盐鼀犨�  z £   矄 ᆠ��   3  꾀 泐 ᨨ  ��  �  鼀 �盐鼀 ҈ ��  泐   ᆠᨨ A =  � +     ҈ ├ �矄 � ᆠ�   ᨨ      ᨨ 矄�ᨨ  �    盐 � ᆠᨨ �    �ᆠ�ᨨ  ᨨ    ᆠ 泐� 鼀 �盐鼀 ᲼҈黨黨黨㜠҈㝐├矄桌 �� �矄� ᆠ�    � a ᨨ ᨨ   ᨨ   矄 ᆠ泐� �ᆠᨨ ᨨ  ᆠ��  m鼀�   矄盐ᨨ m矄ᨨ  ��  � � ᨨ  ᨨ矄

ᨨ鼀� ᨨ鼀 ᆠ盐 矄盐 ᆠᨨ ᨨ �矄ᆠ�ᨨ  盐ᨨ  a ᲼҈黨黨㜠㝐├矄桌





ᔴ �㡰

␔ 矄 ᨨ盐  鼀� �鼀盐鼀 ᆠ��  n ᨨ  �矄ᨨᨨ矄矄�䁸 ��㡰 ᨨ n = � �矄�ᨨ矄矄�ᨨᆠ � �矄犨�   �  B⼄盐ᨨ �矄䁸 ᲼҈黨䰘㜠䰘㝐├矄桌

m a

Topic-3 : Refraction at Curved Surface Lenses and Power of Lens



꾀ᨨ� �├ᨨᆠ�矄ᆠ  �矄 ᆠᨨ ҈鼀�  ᨨ ᨨ  ᆠᨨ   矄ᨨ  ᨨᆠ � �鼀꾀 鼀�ᨨ�矄ᆠ  �矄 ᆠᨨ 鼀 �   矄 ᨨ矄��ᨨ   盐ᨨ   � �鼀� ᨨ鼀 泐 矄泐矄鼀�矄᲼㝐� 和 ᔼ㡰桌 㡰 鼀 ᨨ鼀 鼀�ᨨ 㡰 ҈鼀 ᨨ鼀 鼀�ᨨ�盐 ᆠ㡰 ҈鼀 ᨨ鼀 鼀�ᨨ 㡰 鼀 ᨨ鼀 鼀�ᨨ�盐 꾀 ᨨ盐ᆠᨨ   矄 矄ᨨ犨P 矄鼀 ��ᨨ ᆠ盐㜠 盐Rᨨ ᨨ  矄盐 ᆠ矄  �盐矄ᨨ ᆠ盐盐ᨨ  矄盐 ᆠᨨ  ᨨ㜠ᆠᨨ   矄鼀 ᨨ  矄鼀鼀� 犨� ᨨ犨҈�P�矄 ᲼㝐� 和 ᔼᔼ㡰桌 R R R 㡰 R 㡰 ᆠ㡰 㡰   



ᨨᆠᨨ ᆠ 矄ᨨ  ᨨᆠ � f �ᨨ 犨

ᨨᆠ �鼀� �矄 ᆠ矄u v矄ᆠ�泐 ᨨ鼀�矄 ᨨᆠ 矄矄  泐 u㦨v�矄   ᆠ� 㡰 ᲼㝐� 和� ᔼ㡰桌 v f

盐 㦨 v

҈

MCQs with One Correct Answer

㡰

f v f

盐

盐 㦨 v

1

㡰

f

盐

WWW.JEEBOOKS.IN

EBD_8341 P-250

= u

v f

v

Physics

(c)

u

f v

v f

= u

8. (d)

f 4.

5.

(b) 9

(c) 5

(d)

17

One plano-convex and one plano-concave lens of same radius of curvature ‘R’ but of different materials are joined side by side as shown in the figure. If the refractive index of the material of 1 is m1 and that of 2 is m2, then the focal length of the combination is : [Main 10 Apr. 2019 I]

(a)

R m1 - m2

(b)

2R 2(m1 - m2 )

(d)

2R m1 - m2

R 2 - (m1 - m2 ) The graph shows how the magnification m produced by a thin lens varies with image distance v. What is the focal length of the lens used ? [Main 10 Apr. 2019 II]

(c) 6.

u

A thin lens made of glass (refractive index = 1.5) of focal length f = 16 cm is immersed in a liquid of refractive index 1.42. If its focal length in liquid is fl ,then the ratio fl /f is [Main 7 Jan. 2020 II] closest to the integer: (a) 1

4 3 (b) (c) (d) 3 2 3 2 An upright object is placed at a distance of 40 cm in front of a convergent lens of focal length 20 cm. A convergent mirror of focal length 10 cm is placed at a distance of 60 cm on the other side of the lens. The position and size of the final image will be : [Main 8 April 2019 I] (a) 20 cm from the convergent mirror, same size as the object (b) 40 cm from the convergent mirror, same size as the object (c) 40 cm from the convergent lens, twice the size of the object (d) 20 cm from the convergent mirror, twice the size of the object A convex lens (of focal length 20 cm) and a concave mirror, having their principal axes along the same lines, are kept 80 cm apart from each other. The concave mirror is to the right of the convex lens. When an object is kept at a distance of 30 cm to the left of the convex lens, its image remains at the same position even if the concave mirror is removed. The maximum distance of the object for which this concave mirror, by itself would produce a virtual image [Main 8 Apr. 2019 would be : II] (a) 30 cm (b) 25 cm (c) 10 cm (d) 20 cm What is the position and nature of image formed by lens combination shown in figure? (f1, f2 are focal lengths) [Main 12 Jan. 2019 I]

(a)

9.

10.

2 cm A

20 cm

B

f1 = + 5 cm

f2 = –5 cm

(a) 70 cm from point B at left; virtual (b) 40 cm from point B at right; real 20 cm from point B at right, real 3 (d) 70 cm from point B at right; real 11. Formation of real image using a biconvex lens is shown below : [Main 12 Jan. 2019 II]

(c)

a b b2 b2c (b) (c) (d) c c ac a A thin convex lens L (refractive index = 1.5) is placed on a plane mirror M. When a pin is placed at A, such that OA = 18 cm, its real inverted image is formed at A itself, as shown in figure. When a liquid of refractive index µi is put between the lens and the mirror, the pin has to be moved to A’, such that OA’ = 27 cm, to get its inverted real image at A’ itself. The value of µi will be:[Main 9 Apr. 2019 II]

(a)

7.

2f 2f

f

screen

f

If the whole set up is immersed in water without disturbing the object and the screen positions, what will one observe on the screen ? (a) Image disappears (b) Magnified image (c) Erect real image (d) No change

WWW.JEEBOOKS.IN

P-251

Ray Optics and Optical Instruments

҈

҈

҈

҈�

҈

꾀 ᨨᆠ�矄 �矄 ᆠᨨ 鼀 ᨨ鼀ᆠᨨ   矄ᨨ  ᨨᆠ  � 鼀  矄 ᨨ鼀矄 �鼀�ᨨ  ᨨᆠᔼ   ᨨᆠ鼀ᨨ矄犨泐 ᨨ鼀  矄矄 ᨨ �鼀⏌矄 矄   �ᆠ�ᨨ ᨨ  �鼀�犨� ᲼㝐� ҈҈ ҈黨ᔼ桌 㡰 맔҈鼀⏌矄犨泐 ᨨ鼀  矄 㡰 黨맔҈鼀⏌矄犨泐 ᨨ鼀  矄 ᆠ㡰 맔҈鼀⏌矄ᨨ犨 矄  矄 㡰 ҈҈맔҈鼀⏌矄ᨨ犨 矄  矄 꾀  ᨨ ᆠᨨ    矄 ᨨ   ᆠ� �   m҈   ᨨᆠ  � f҈�矄├� ᆠᨨ ᆠ犨�  ᨨ  ᨨᆠᨨ ᆠ  矄 ᨨ   ᆠ� �   m   ᨨᆠ  �  f ᔼ     �盐矄 ᨨ ᆠ盐盐 ᨨ  � 矄 �ᆠ  ᆠ矄 �矄  ᆠ  f҈ 㦨 f   m҈  m   矄 ᲼㝐� ҈   ҈黨 ᔼ桌 㡰 m҈졔m㦨 㡰 m҈m㦨҈ ᆠ㡰 mm҈㦨҈ 㡰 mm҈㦨҈

泐ᆠ �  矄矄� � ᆠ� �矄盐 ᆠ

 �盐矄ᨨ ᆠ盐盐 ᨨ  �矄 矄盐 ᆠ�矄⼄盐 ᨨ  ᨨ ᆠᨨ  䰘鼀鼀㡰 �矄矄盐 ᆠ矄矄犨ᨨ鼀 �ᨨ  ᆠ�� �ᆠ矄҈ ҈ᔴᆠ盐  �矄 ᆠ ᨨ鼀   ᆠ� �矄盐 ᆠ犨 �ᆠ 鼀ᨨ ��  ᲼㝐� ҈   ҈黨 ᔼᔼ桌 犨�ᆠᨨ鼀ᨨ ᨨᆠ盐矄 㡰 ҈ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ҈ᆠ鼀 꾀ᆠᨨ   矄�矄盐҈ᆠ鼀 ᨨ鼀 �� 矄ᨨ盐ᆠ  � 鼀├矄矄 �鼀�ᨨ 矄ᆠ ├҈ᆠ鼀 ᨨ鼀   矄ᨨ犨�矄矄ᨨᆠ├  ᆠ��  ҈�㡰ᨨ ҈�ᆠ鼀  �ᆠ├ 矄矄�矄ᆠ � ᆠᨨ ᆠ犨�  �� 矄ᨨ盐ᆠ ᨨ �   矄  �鼀� ��    矄ᆠ鼀 �矄 矄 �  泐 �矄 ᆠ    �矄 ᲼㝐� 黨 ҈黨ᔼ桌 㡰 ҈҈ᆠ鼀犨泐 ᨨ鼀  矄 㡰  ᆠ㡰 ��ᆠ鼀ᨨ犨 矄  矄 㡰 ��ᆠ鼀犨泐 ᨨ鼀  矄 꾀 ᨨᆠᨨ   矄ᆠᨨ鼀矄 ᨨ�ᆠ矄泐矄鼀ᨨ ᆠ鼀 ᨨᆠ  �  犨   �矄   矄盐 ᆠ �矄 矄�   �盐鼀�   ᨨ鼀 ᨨ�� 矄矄 ᨨ犨 �  ��㜠꾀ᔼ  矄鼀  矄 �矄 � 矄  矄�  ᨨ    ᆠ盐  矄盐 ᆠ  �盐鼀�   ᨨ鼀ᨨ 矄� 矄�  ���ᆠ矄�├ ᨨ�ᆠ 矄泐矄鼀ᨨ  ᨨᆠ � ҈ᆠ鼀  ᆠ��  ᨨ   鼀�ᨨ  矄�  ᲼㝐� 졠 � 꾀�҈�҈桌

��꾀

҈䰘

҈

��

㡰 ҈� 㡰 ҈�� ᆠ㡰 ҈䰘� 㡰 ҈�҈ ᔼ   �鼀 ᆠᨨ   矄ᨨ  ᨨᆠ � ҈�ᆠ鼀�矄 ᆠ ᆠᨨ �泐ᨨ  ᨨ�ᆠ ᆠ �  ᨨ ᨨ ᆠᨨ  鼀�ᨨ �矄 ᆠᨨ �ᆠ鼀 ᨨ鼀�ᔼ�矄 ᨨ盐  

ᨨᆠ �矄�鼀�ᆠᨨ� ᆠ� �  ᨨᆠ�矄ᆠ  �矄 ᆠᨨ ᆠ鼀 ᨨ鼀  矄  ᨨᆠ � ᨨ   ᲼㝐� 졠 � 꾀�黨҈䰘桌 ᆠᨨ  鼀�ᨨ�矄 㡰 䰘�ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 �ᆠ鼀 㡰 �ᆠ鼀 꾀 鼀�矄 �ᆠ�矄矄ᨨ 泐ᨨ  �盐矄҈ᆠ鼀  ᆠ� �  ҈��矄矄� ᨨ �矄ᆠ盐 矄盐 ᆠ꾀矄鼀�盐 �矄ᆠ鼀ᨨ犨  矄盐 ᆠ� 矄� �ᨨ �  �矄  ᨨ矄��ᨨ ᨨ  �鼀�ᨨ  �盐鼀 泐 鼀�ᨨ �矄矄  ᲼㝐� 졠 � 꾀�҈҈桌

҈ᆠ鼀 ᆠ鼀 졠

和� 㡰 ҈ᆠ鼀ᨨ犨 矄盐 ᆠ 㡰 ᆠ鼀ᨨ犨 矄盐 ᆠ ᆠ㡰 ҈ᆠ鼀ᨨ犨 矄盐 ᆠ 㡰 ᆠ鼀ᨨ犨 矄盐 ᆠ ҈黨 꾀ᆠᨨ   矄ᨨ  ᨨᆠ � ᆠ鼀ᆠᨨ ᆠ 矄ᨨ ᨨᆠ � ҈ᆠ鼀  鼀�ᨨ � 矄 矄 ᨨ犨  ᨨ ᨨᆠ├ �矄 ᆠᨨ ᆠ鼀 ᨨ鼀  ᆠᨨ   矄  � �鼀� ᨨ鼀 泐 ᆠᨨ鼀� �ᨨ �矄 �鼀� �矄 ᆠᨨ ᲼㝐� 졠 � 꾀�黨҈桌

 ᨨᆠ �  ᨨᆠ �  㦨ᆠ鼀㦨҈ᆠ鼀 ᆠ鼀 ᆠ鼀 䰘ᆠ鼀 㡰 ᆠ鼀 ᨨ鼀 ᆠᨨ   矄 㡰 ᆠ鼀 ᨨ鼀 ᆠᨨ ᆠ 矄 ᆠ㡰 䰘ᆠ鼀 ᨨ鼀 ᆠᨨ   矄 㡰 䰘ᆠ鼀 ᨨ鼀 ᆠᨨ ᆠ 矄  꾀 � ᆠᨨ   矄ᨨ  ᨨᆠ � � �矄盐ᨨ   鼀�ᨨ矄矄 ᨨ犨 �   ��盐␔   ᨨᆠ�矄├  �矄 ᆠ� ᨨ鼀  矄㜠鼀�ᨨᆠᨨ鼀� �ᨨ �矄�鼀� a �矄 ᨨ鼀    �矄 ᆠ  �  ᨨ  ᨨ    ᆠᨨ鼀� �ᨨ  3 ᲼㝐� 졠 � 꾀�҈҈ ҈�桌

盐ᨨ ��矄

㡰 

㡰

3 2

ᆠ㡰

㡰 

ö æ ҈ 꾀 � ᆠᨨ   矄鼀  ᨨ鼀ᆠᨨ犨 �矄矄 ç m = ÷  矄 ø è ᨨᆠ �  ␔  ��矄鼀矄盐 � 犨ᨨ �  �⼄盐� 矄  � � � ᆠ�� �ᆠ矄   � 矄  ᨨᆠ � 矄   ҈  矄ᆠ�泐 ᆠᨨᆠ �ᨨ  犨    ᨨᆠ � 矄�矄 ᲼㝐� ҈桌 㡰 ҈㦨  㡰 ҈>   ᆠᨨ鼀矄 �� ᆠ㡰 >   ҈ᆠᨨ鼀矄 �� 㡰 ҈  ᨨ ᆠᨨ鼀 ��

WWW.JEEBOOKS.IN

EBD_8341 P-252



Physics

 ᆠ��  ᨨ  鼀�ᨨ ᆠᨨ ᆠ 矄�矄mᔼ �矄�鼀鼀矄 � 鼀 �盐鼀ᨨ  ᆠ��  m҈꾀 鼀ᨨ �� �矄� ᆠ�  ᨨ   矄  ᨨ  鼀�  泐矄犨  m҈>m�矄 ᲼㝐� 졠 � 꾀�҈҈桌 m m҈



㡰 ҈鼀 㡰 鼀 ᆠ㡰 鼀 㡰 鼀  꾀矄鼀ᨨᆠ�矄ᆠ �ᆠ鼀ᨨ  ᨨ  � ᆠᨨ   矄ᨨ  ᨨᆠ � ᆠ鼀꾀ᆠᨨ  矄 �ᆠ鼀�ᨨᨨ  �盐矄ᨨ ᆠ盐盐҈ᆠ鼀�矄ᆠ ᨨ �� ᨨ    矄 �矄 ᆠᨨ �ᆠ鼀 鼀�ᨨ�矄� 矄盐ᆠ     �矄ᨨ  鼀�ᨨ�矄  �q㦨 ᨨ  �矄ᨨ    矄矄矄 ᨨ犨 �   ��盐 㦨ᆠ鼀

㡰

q 㡰

�㡰

m m҈

�ᆠ鼀

� + �



㡰 㡰

m

ᆠ㡰



ᆠ㡰

 -�㡰

ᔼ  ᨨ��� ᨨ  ᆠᨨᨨ � 矄泐矄鼀�矄├ ᨨ  ᆠ ᨨ   矄 ᆠᨨᨨ � 矄 �  ᆠ鼀㡰 ᨨ  ᨨ�  泐㡰犨 �ᆠ  �鼀��矄 ᨨ鼀  ᲼꾀 ҈桌

㡰





 㦨 ҈ ᆠ 鼀

� � 㡰

㡰 㡰

� 㜠 �  �㡰 ҈� ⏌  � 㡰

䰘 꾀�㜠ᆠᨨ   矄�矄 ᨨ鼀 犨� 犨ᨨ �  ᨨ㜠ᆠᨨ   矄矄矄矄 ᨨ犨 �   ��盐  ᆠ��  nᨨ   �矄 矄�矄҈�  ᨨ  矄ᆠᨨ  矄�矄҈ᨨ   ᆠ盐 矄盐 ᆠᨨ  矄鼀 �盐矄ᨨ ᆠ盐盐R㦨҈ ᆠ鼀 ᨨ �矄�㜠ᆠᨨ   矄 ᨨ ᨨᆠ �矄 ᆠᨨ  ᆠ鼀 �鼀� �矄 ᆠ犨� ᲼҈桌

m m҈



㡰  



�

�鼀ᨨ  ᨨ㜠ᆠᨨ   矄�矄ᆠ鼀  �ᆠ├ 矄矄  ᆠ �矄鼀鼀ᔼ 矄 ᨨ �� � 鼀�ᨨ  矄�矄 맔҈鼀⏌矄  ᨨᆠ � ᨨ   矄�矄 ᲼㝐� ҈桌 㡰 ҈�ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ҈ᆠ鼀

�鼀�ᨨ  �盐鼀�  矄⼄盐�矄ᨨ�  ᨨ 矄ᆠ

犨�   ᨨ ᆠᨨ �� � 矄  �矄 ᆠᨨ   矄⼄盐 ᨨ鼀  矄�矄ᆠ鼀 ᨨ  �鼀��矄黨 �鼀矄 ᨨ  矄⼄盐  ᨨᆠ � ᨨ   矄�矄 ᲼㝐� 졠 � 꾀�҈桌 㡰 ᆠ鼀 㡰 䰘ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ᆠ鼀

�鼀�ᨨ  ᨨᆠ ᨨ鼀 泐 ᨨ㜠ᆠᨨ   矄  �矄 ᆠᨨ 鼀 �   矄�矄�矄ᨨ 㜠 �   矄� ᨨ  ᨨᆠ 犨 � ᨨ �� � 矄�   矄  �矄 �鼀矄 犨 � �  矄ᆠ  �盐矄ᨨ    ᆠ盐 矄盐 ᆠᨨ   矄�矄 ᲼꾀 ҈桌

黨

 㡰 㜠ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ҈�ᆠ鼀 㡰 ҈ᆠ鼀 泐矄ᨨ ��  ᨨ鼀和盐  矄ᨨ �ᆠᨨ   矄ᨨ  ᨨᆠ  �    ᆠ�ᆠ盐�鼀�ᨨ 和盐 ᨨ  �盐矄�矄 ᨨ鼀 ᨨ   ᨨᆠ ᨨ   矄 

᲼䰘桌 㡰 꾀ᨨ �鼀��矄p �矄 �ᆠ泐ᨨᨨ�ᨨ ᨨ f 㡰 꾀ᨨ �鼀��矄p �矄 �ᆠ泐ᨨᨨ�ᨨ ᨨf  ᆠ㡰 ᔼ  矄�泐ᨨ �鼀�� ᆠ矄矄�  �矄� ᆠ矄 㡰 ᔼ ᨨ犨  ᨨ   矄�矄ᆠᨨ 犨� ᆠ├ 犨�ᆠᨨ鼀  꾀�ᆠᨨ   矄ᨨ  ᨨᆠ � ҈�ᆠ鼀�矄�  ᨨ ᨨ   鼀�ᨨ  �矄 ᆠ犨   矄  鼀�ᨨ�矄҈ ᆠ鼀꾀矄鼀ᨨᆠ�矄├ �矄 ᆠᨨ ᆠ鼀 ᨨ鼀   矄  � �鼀��矄 ᲼҈桌 㡰 �盐  �矄 ᆠᨨ ҈ᆠ鼀 ᨨ鼀 鼀�ᨨ 㡰   �矄 ᆠᨨ ҈ᆠ鼀 ᨨ鼀 鼀�ᨨ ᆠ㡰 �盐  �矄 ᆠᨨ ᆠ鼀 ᨨ鼀 鼀�ᨨ 㡰   �矄 ᆠᨨ ᆠ鼀 ᨨ鼀 鼀�ᨨ

WWW.JEEBOOKS.IN

P-253

Ray Optics and Optical Instruments



 �  矄 ᨨ犨矄 �ᨨ 矄 � 犨  ᨨᆠ �矄 ᆠ   �鼀� �矄 ᆠ ᨨ  ⼄盐�ᆠᨨ    矄   ᨨᆠ  � ᨨ   矄�矄 ᲼㜠㝐桌桌 ҈ ᆠ鼀



҈

盐ᆠ鼀҈ 

҈



҈

 黨졔黨㡰

㡰 �᠀�ᆠ鼀 㡰 �᠀҈ᆠ鼀 ᆠ㡰 �᠀�ᆠ鼀 㡰 �᠀҈ᆠ鼀 ᨨᆠ � ᨨ   ᨨ㜠ᆠᨨ   矄�矄҈�ᆠ鼀꾀矄鼀 ᨨᆠ�矄ᆠ 꾀矄矄 ᨨ犨 �    ��盐   矄盐 ᆠ�矄矄�  �鼀�犨� ᨨ鼀᲼㜠㝐҈桌

 꾀 �鼀� �矄  �鼀�ᨨ  ᨨᆠ�矄ᨨᨨ�  ᨨ  矄ᆠ ҈鼀 ᨨ鼀� �矄ᆠ ᆠ � 泐ᨨ�泐 ᆠ� � ᲼҈黨黨�和桌 㡰 ᆠᨨ ᆠ鼀�ᨨᨨ 矄盐� ᨨᆠ � 㡰 ᆠᨨ  鼀�ᨨᨨ 矄盐� ᨨᆠ � ᆠ㡰 ᆠᨨ   矄ᨨ  ᨨᆠ � 矄矄  �鼀 㡰 ᆠᨨ ᆠ 矄ᨨ 矄盐� ᨨᆠ � 䰘 和 �ᆠ�ᨨ �  �  矄ᆠ  盐ᆠ 泐 㡰 盐矄� �鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ��  ᲼҈黨黨㜠҈㝐├桌 㡰 盐矄� � ᨨ盐ᆠᨨ鼀� �ᨨ

ᆠ㡰 盐矄� �ᆠ�ᆠ盐

盐鼀├ᨨ  矄 㡰 � ᆠ矄� � 矄� ᨨ   矄  ᔴᨨ 矄� ᆠᨨ ᆠ鼀�ᨨ ᆠᨨ   矄  ᆠ� �  㦨҈�㡰ᨨ  ᨨᆠ � ҈ᆠ鼀ᆠ 矄 泐 �矄 ᆠᨨ �ᆠ鼀� �  ᆠ��  㦨҈㡰矄矄 ᨨ犨 �

  ��盐꾀 ᨨᆠ�矄ᆠ  �矄 ᆠᨨ ҈�ᆠ鼀 ᨨ鼀  鼀�ᨨᔼ矄ᆠ�鼀� ᨨ鼀 泐 �矄ᆠᨨ鼀� �ᨨ  矄 鼀� � �ᆠ�ᨨ M҈␔   矄㜠盐�矄├� 鼀 �盐鼀ᨨ 䰘  ᆠ��    鼀� � �ᆠ�ᨨ ᆠᨨ鼀矄M   鼀� �盐 



M �矄 M҈

ᆠ鼀

㡰 ᆠ鼀ᨨ  ᨨ  矄 㡰 ҈ᆠ鼀ᨨ  ᨨ  矄 ᆠ㡰 ᆠ鼀ᨨ �� ᨨ  矄 㡰 ᆠ鼀ᨨ  ᨨ  矄  꾀 ᆠᨨ    矄 �矄 �  ᆠᨨ ᆠ 犨�  ᆠᨨ ᆠ  矄  鼀� �盐 ᨨ  �ᨨᨨ  � ᨨᆠ � �矄⏌ � ⼄盐�  ᨨᆠ � �矄ᆠ鼀␔  �� �� 盐 ᨨᆠ � 矄䁸 ᲼�和桌 㡰 ҈�҈ 㡰 ҈҈� ᆠ㡰 䰘�� 㡰 䰘��  矄� ᨨ  �鼀�ᨨ  ᨨᆠ犨 �ᆠ �矄� � �泐矄 ᨨ鼀 泐ᆠᨨ   矄ᨨ  ᨨᆠ � ᆠ鼀�矄ᆠ鼀ᔼ  ᆠᨨ ᆠ 矄ᨨ  ᨨᆠ � ᆠ鼀�矄ᆠ 犨   ᆠᨨ   矄  �鼀� �矄 ᆠᨨ ᆠ鼀 ᨨ鼀  ᆠᨨ   矄ᆠᆠ盐  犨矄� ᨨ  �鼀�᲼和桌 㡰 ҈�ᆠ鼀 㡰 �ᆠ鼀 ᆠ㡰 ҈�ᆠ鼀 㡰 ᆠ鼀  꾀 ᨨᨨ犨 ᨨ盐 ᆠᨨ ᆠ  矄 �矄 鼀  ᨨ  泐  �

 矄 鼀�ᔼᆠ  � 犨� �ᨨ� ᨨ 犨ᨨ �⼄盐� 矄 L҈ ᨨ L � �  ᆠ� � �ᆠ矄 m҈   m 矄ᆠ�泐 m>m҈>҈㡰  矄犨� �� 鼀ᨨ �� � ��矄 � 犨� ᲼和桌 㡰 � ᆠ � � 㡰 � �鼀鼀矄 � L҈ ᆠ㡰 L҈ �鼀鼀矄 � L 㡰 L �鼀鼀矄 � L҈ � 꾀 ᆠᨨ ᆠ  矄 ᨨ  �矄矄  ᆠ� �   ҈� 矄 ᨨ 矄盐 ᆠ矄ᨨ 矄鼀 �盐矄ᨨ ᆠ盐盐R졠 �鼀鼀矄�ᨨ �  鼀 �盐鼀ᨨ  ᆠ��  ҈䰘��犨� 矄 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 ᆠᨨ �  矄ᨨ  ᨨᆠ � �R 㡰 ᆠᨨ �  矄ᨨ  ᨨᆠ � R ᆠ㡰 ��  矄ᨨ  ᨨᆠ � �R 㡰 ��  矄ᨨ  ᨨᆠ � R

҈�ᆠ鼀



᲼꾀 ҈�桌 �ᆠ鼀

2

Integer Value Answer

黨  ᨨᆠ � ᨨ  � �ᆠᨨ   矄�矄ᆠ鼀␔  

ᨨᆠ�矄鼀ᨨ  ᨨ鼀 �矄 ᆠᨨ �ᆠ鼀�  ᨨ ᨨ �ᨨ� ᆠ鼀 鼀� � �ᆠ�ᨨ ᨨ �矄�鼀�ᆠ  �矄 ᨨ鼀鼀�ᨨ m� 鼀� �ᨨ �矄 ᲼҈桌 m� 3

Numeric Answer

  �矄 ᆠ犨  ᨨᆠ 矄ᆠ �矄҈ᆠ鼀꾀  矄ᆠ ᨨ 盐ᆠ�鼀�ᨨ  ᨨᆠᨨ  矄ᆠ  ᨨ 犨ᨨ �  ᨨ矄��ᨨ 矄犨  矄ᆠ   ᨨᆠ

 �矄 ᆠ犨  矄犨ᨨᨨ矄��ᨨ 矄�矄ᆠ鼀ᔼ   æ N ö ᨨ犨ᨨ   矄�矄ᆠᨨ矄ᨨ ç D 犨 N�矄 � � è ҈ ÷ø  盐ᨨ N�矄힘힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌 ҈ 꾀ᨨ� ᨨᆠ� ��矄�  ᨨ ᨨ  ᆠ盐 矄盐 ᆠᨨ  planᨨ㜠cᨨnvex 矄  �盐矄ᨨ ᆠ盐盐ᨨ  ᆠ盐 矄盐 ᆠ�矄ᆠ鼀   ᆠ��  ᨨ   矄鼀� �矄 ҈�      ᨨᆠ  �  ᨨ     矄  �  ᆠ鼀㡰 �矄힘힘힘힘힘힘힘힘힘힘 ᲼㝐�  ᔼ桌 4

Fill in the Blanks

 犨ᨨ �  矄矄犨  � ᆠᨨ ᆠᨨ 盐ᆠᆠᨨ鼀� �ᨨ

ᨨ ᨨ犨졔҈ �ᨨ矄␔   泐�鼀  ᨨ犨  盐ᆠ矄 ᨨ졔 �ᨨ矄  ᨨᆠ  �  ᨨ    矄矄m m ᲼҈黨黨䰘㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-254





�



Physics

꾀 �  矄ᨨ  ᆠ��  ҈� 矄 ᨨᆠ � ᨨ ҈�ᆠ鼀 � �␔    矄�矄ᆠ � 鼀 �盐鼀ᨨ  ᆠ��   �矄 ᨨᆠ � 犨�ᆠᨨ鼀ᆠ鼀 ᲼҈黨䰘㜠㝐├矄桌  꾀ᆠᨨ   矄Aᨨ  ᨨᆠ � ᆠ鼀 ᆠᨨ ᆠ 矄 Bᨨ  ᨨᆠ � �ᆠ鼀├ᨨ � 矄鼀 �矄犨�  �矄 ᆠd犨  鼀ᔼ 鼀ᨨ ��  � � ᨨ A矄B矄鼀  d�矄⼄盐ᨨᆠ鼀 ᲼҈黨�㜠㝐├矄桌

5 True / False 꾀鼀ᨨ 犨 ���  ᨨ ᆠᨨ鼀� �ᨨ ᨨ  ᆠᨨ ᆠ  ᆠᨨ    矄 ᨨ  ᨨ  矄鼀鼀�

� ᨨᆠ � 矄҈�ᆠ鼀 ᆠ鼀矄ᆠ�泐 ᨨ  鼀 犨 � � 犨 ��� 졠  ᨨ 矄� ᨨ   矄 矄泐矄鼀 ᨨ 矄矄 ᆠᨨᨨ盐  矄 犨�  �ᨨ ᆠᨨᨨ盐 ᨨ盐 � ᲼҈黨㜠㝐├矄桌 꾀ᆠᨨ   矄ᨨ  ᨨᆠ � ҈鼀 ᆠᨨ ᆠ 矄 ᨨ  ᨨᆠ � �鼀├䰘�鼀꾀 鼀ᨨ ��  �矄矄矄矄 ᨨ盐�  ᆠᨨ   矄 

 ᨨ盐�   ᆠᨨ ᆠ  矄  ᆠᨨ鼀矄 ᨨ   ᨨᆠ盐矄 � 鼀 犨泐 ᨨ鼀 ᆠᨨ ᆠ 矄 ᲼҈黨㜠㝐├矄桌 6

䰘

MCQs with One or More than One Correct Answer

 꾀├ᨨ  �盐矄r�矄 � 犨� 犨  ᆠ��   㡰盐  ᨨ �� H矄矄 ᨨ犨 �   ��盐ᨨ    ├�矄 ├ᨨ  ᨨ� ᨨ ᨨ� �犨�  �盐矄 w �矄 鼀├矄 犨矄盐 ᆠᆠ盐 矄ᨨ   �  ᆠ�   �� ᨨ 犨 ᆠ   ᆠ�ᆠ盐鼀  ᆠᨨ  ├�矄 h h = H  h = r 㡰 矄矄 ᨨ犨 �   ��盐ᨨ

 ��  ├ �矄矄盐 ᆠᨨᨨ �鼀泐矄 �ᆠ犨�  �盐矄ᨨ ᆠ盐盐R␔ �ᆠ ᨨ   ᨨᨨ犨� ��矄⏌ᆠᨨᆠ䁸 g�矄 ᆠᆠ�ᨨ  盐ᨨ��泐㡰 w

h

H

㡰 R =

h + r  h

r  h ᆠ㡰 꾀    ᨨ  ᨨᨨ鼀 ᨨ  ├ �矄ᆠᨨ矄

 꾀 ᨨᆠᨨ   矄�矄鼀 ᨨ 鼀�ᨨ  ᆠ� �   ␔  矄鼀ᨨᆠ�矄ᆠ ᆠ鼀犨泐�  ᨨ  ᨨ  ᆠ盐 矄盐 ᆠᨨ   矄 �鼀�ᨨ  ᨨ盐  矄� ᨨ  ᨨᆠ�矄ᨨ 盐ᆠ 盐ᨨ ᆠ�ᨨ  ᨨ鼀  ᆠᨨ  矄盐 ᆠᨨ   矄 ᨨ  � �鼀��矄ᨨ矄  �矄 ᆠᨨ ҈ᆠ鼀犨泐 ᨨ鼀  矄␔ �ᆠ ᨨ   ᲼꾀 ҈桌 ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 㡰  ᆠ��  ᨨ   矄�矄� 㡰  �盐矄ᨨ ᆠ盐盐ᨨ  ᆠᨨ  矄盐 ᆠ�矄�ᆠ鼀 ᆠ㡰  � �鼀��矄ᆠ  㡰  ᨨᆠ � ᨨ   矄�矄ᆠ鼀 黨 꾀矄 �ᆠ矄盐 ᆠᨨ  �盐矄ᨨ ᆠ盐盐 矄矄�  ᆠ��  ҈㡰 ᨨ鼀�矄矄  ᆠ��  ҈�㡰  ᆠ ᨨ ᆠ盐盐�矄�  �矄矄꾀ᨨ� ᨨᆠᆠ � ��矄 ᨨ盐 ᨨ �鼀�Q�  �矄矄 �  PQ ᆠ盐矄  矄盐 ᆠ   ᨨ�  O   PO 㦨 OQ  ᲼҈黨黨㜠㝐├矄桌 �矄 ᆠPO�矄⼄盐ᨨ 㡰 �R 㡰 R ᆠ㡰 R 㡰 ҈�R � 꾀�鼀�ᨨ  �矄 ᨨᆠ�矄 ᨨ鼀 泐 ᨨ㜠ᆠᨨ   矄ᨨ �矄� ᆠ� �矄和 �ᆠ�ᨨ

㡰 �矄矄  ᲼ ҈黨黨㜠㝐├矄桌 㡰 �矄矄鼀�  ᆠ盐 矄盐 ᆠᨨ   矄 ᆠ矄 ᨨᆠ ᆠ㡰 �矄矄鼀�   矄盐 ᆠᨨ   矄 ᆠ矄 ᨨᆠ 㡰 �矄 矄鼀犨 �ᆠ 矄� ᨨ   矄 ᆠ矄 ᨨᆠ �҈ ␔ �ᆠ ᨨ   ᨨᨨ犨� � ᨨ鼀 矄㡰�盐 ᆠ�鼀� ᨨᨨ矄��ᨨ 矄ᨨ  ᨨᆠ䁸 ᲼҈黨黨㜠㝐├矄桌 㡰 ᔴᨨ   矄 㡰 ᔴᨨ ᆠ 矄 ᆠ㡰 ᔴᨨ  鼀�ᨨ 㡰 ᔴᨨ ᆠ鼀�ᨨ � 꾀ᆠᨨ �� � 矄�矄盐矄 ᨨ ᨨ鼀 �鼀�ᨨ 矄ᆠ  ␔   盐  ᨨ   矄�矄ᆠᨨ 泐 ᨨ⼄盐 矄ᆠ

᲼҈黨㜠㝐├矄桌 㡰   �鼀�犨� �矄 㡰 ᆠᨨ鼀�鼀�犨� ᨨ鼀  ᆠ㡰 �  矄�泐ᨨ  �鼀�犨�� ᆠ矄 㡰 �  矄�泐ᨨ  �鼀�犨� ᆠ矄 � 꾀ᆠᨨ   矄ᨨ  ᨨᆠ � ᆠ鼀�矄� ᆠᨨ ᆠ犨�  ᆠᨨ ᆠ 矄 ᨨ  ᨨᆠ  �  � ᆠ鼀  ᨨ犨 ᨨ   ᆠᨨ鼀� �ᨨ �矄 ᲼҈黨㜠㝐├矄桌 㡰 ҈� �ᨨ矄 㡰 � �ᨨ矄 ᆠ㡰 졔� �ᨨ矄 㡰 졔䰘 �ᨨ矄 � ᨨ盐ᆠᨨ鼀� �ᨨ 矄ᨨ 犨ᨨ �  矄矄�� � �矄㜠ᔼ

 �盐矄ᨨ ᆠ盐盐ᨨ ᆠ盐 矄盐 ᆠ矄�矄r    ᆠ� �   ᨨ      矄矄 �矄 ҈� 㝐ᆠ   矄 ᆠᨨ鼀� �ᨨ 矄� �矄㜠ᔼ犨�  � ᨨᆠ � � �矄㜠ᔼᔼ 矄ᆠ ᆠᨨᆠ 矄犨盐矄� � ᆠᨨ �� ᨨ犨  �矄矄 ᲼꾀 ҈桌 �矄㜠ᔼ �矄㜠ᔼᔼ

㡰 R =



҈

r

턼



r 



H æ w H ö ç҈ + ÷ ᨨ  çè  g ÷ø 㡰 꾀   ᨨ  ᨨᨨ鼀ᨨ  ├�矄ᆠᨨ矄ᨨ H æ w H ç҈ +  çè g

ö ÷ ÷ ø



WWW.JEEBOOKS.IN

P-255

Ray Optics and Optical Instruments

ᔴᨨ盐鼀 ᔼ

��





r

和



r

꾀㡰

ᔴᨨ 矄 㡰 㜠҈턼㜠 㜠和㜠 㡰 㜠턼㜠 㜠和㜠҈ ᆠ㡰 㜠턼㜠҈ 㜠和㜠 㡰 㜠턼㜠҈ 㜠和㜠

犨ᨨ 矄 鼀 �ᨨ  ᆠ�� �ᆠ矄 m1  m   矄ᨨ�   矄 矄    矄  鼀� ᨨ   ᆠ� �  m  犨  鼀矄矄 ᨨ犨 �  ��盐矄� ᔴᨨ盐鼀 ᔼᔼ꾀 꾀 泐矄� � 矄鼀 ��矄矄ᨨ矄 ᨨ犨 �   ��盐矄ᔼ

ᔴᨨ盐鼀 ᔼ �  �ᨨ 矄 �矄犨 m҈ m   m   �� 㝐ᆠ  鼀ᨨ 泐 ��鼀矄矄 ᨨ犨 � ᔴᨨ盐鼀 ᔼᔼ ᲼҈桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ

꾀㡰 m҈ < m 

㡰

㡰 m҈ > m 

⼄㡰 m 

ᔴ㡰 m  = m

㡰

m



m



m

m

㡰

ᔴ㡰

㡰

ᔴᨨ盐鼀 ᔼᔼ



㡰 �鼀�



⼄㡰 �盐�鼀�



㡰 鼀� � � �鼀�



矄㡰 �鼀�� � �泐

10 Subjective Problems �䰘 꾀  ᨨᆠ�矄 鼀ᨨ� �犨�  ᨨᆠ�泐҈鼀⏌矄ᨨ犨 矄 ᆠᨨ   矄ᨨ  ᨨᆠ � 鼀 �  鼀� �盐 ᨨ ᨨ 矄�ᨨ ᨨ �鼀� ᨨ鼀  矄犨   ᨨᆠ �矄 �矄 ᆠᨨ 鼀 ᨨ鼀  矄꾀矄ᨨᆠᆠ盐  鼀� �盐  ᨨ     ᨨ  ᆠ  � ᨨ     ᲼㜠㝐├矄桌 鼀� � �ᆠ�ᨨ  � 꾀 �  ᨨ㜠ᆠᨨ   矄ᨨ  ᨨᆠ � f �矄矄�� ᨨ犨ᨨ 矄ᨨ ᨨ   矄�矄矄 �  ᨨ � ᨨ�ᆠ �矄

矄�ᨨ 犨 ᨨᆠ �鼀� 矄�矄҈鼀

鼀� � �ᆠ�ᨨ ᨨ  �鼀� ᨨ鼀 泐ᨨ ᨨ    㜠  矄矄�矄 �   ᨨᆠ㜠 � ᨨ   矄 矄�ᨨ

犨  犨ᨨ 矄犨 泐 ��鼀 ᨨ�鼀� ᨨ鼀�ᨨ  ᲼҈黨黨㜠�㝐├矄桌



m



㡰 m  > m 

矄㡰 m

㡰 m

�

m

҈鼀



m



꾀 ᨨ�ᆠᆠᨨ鼀ᨨ    ᨨᆠ和ᆠ ᨨ ��矄 ᨨ�ᆠ �矄�� � ᔴᨨ盐鼀 ᔼ  �矄 ᆠ犨   ᨨᆠ  ᆠᨨ鼀ᨨ  ᆠ �  ᨨ�矄 ᨨ �鼀�矄�� � ᔴᨨ盐鼀 ᔼᔼ㝐ᆠ  ᨨ�矄 ᨨ �鼀�矄 ᨨ鼀ᔴᨨ盐鼀 ᔼᔼ犨�  ᨨ�ᆠᨨ鼀ᨨ㜠

 矄�� � ᔴᨨ盐鼀 ᔼᔼ �ᆠ泐ᨨ盐 矄犨泐 ├ 㜠 � � ᨨ�盐矄ᨨ  맔鼀� �� �   졠 和 ᲼桌

�黨 꾀 �鼀�Y�矄 ᨨ鼀 ᨨ ᨨ� ᨨᆠX泐 矄犨 ᨨ矄 ᨨ�ᆠ �矄�矄AB矄矄 ᨨ犨 �  ��盐犨泐 ��鼀ᨨ ᨨᆠ  矄 �矄 ᨨᆠ盐矄ᔼ  �鼀�Ӹᨨ  ᨨᆠX �矄 ᨨ鼀 泐ᆠᨨ ᆠ鼀�ᨨ � � 矄鼀 �矄矄 AB㡰� 矄 ᨨ  矄 犨 ᨨ 泐 ��鼀ᨨᨨᆠ  鼀�ᨨ �矄 ᨨᆠ盐矄␔� ᨨ犨  矄矄ᨨ ᆠᨨ 矄盐ᆠ�ᨨ

᲼҈黨黨㜠㝐├矄桌 ᨨ  泐 ��鼀矄  



Ӹ

WWW.JEEBOOKS.IN

EBD_8341 P-256

60.

Physics

In Fig., S is a monochromatic point source emitting light of wavelength l = 500nm. A thin lens of circular shape and focal length 0.10 m is cut into two identical halves L1 and L2 by a plane passing through a diameter. The two halves are placed symmetrically about the central axis SO with a gap of 0.5 mm. The distance along the axis from S to L1 and L2 is 0.15 m while that from L1 and L2 to O is 1.30 m. The [1993 - 5+1 Marks] screen at O is normal to SO. L1

A

0.5mm

S

O

62. A plano convex lens has a thickness of 4 cm . When placed on a horizontal table, with the curved surface in contact with it, the apparent depth of the bottom most point of the lens is found to be 3 cm. If the lens is inverted such that the plane face is in contact with the table, the apparent depth of the centre of the plane face is found to be 25/8 cm. Find the [1984- 6 Marks] focal length of the lens. 63. The convex surface of a thin concavo-convex lens of glass of refractive index 1.5 has a radius of curvature 20 cm. The concave surface has a radius of curvature 60 cm. The convex side is silvered and placed on a horizontal surface. [1981- 6 Marks]

Screen

L2 0.15m

1.30m

(i)

61.

If the third intensity maximum occurs at the point A on the screen, find the distance OA. (ii) If the gap between L1 and L2 is reduced from its original value of 0.5mm, will the distance OA increase, decrease, or remain the same? Monochromatic light is incident on a plane interface AB between two media of refractive indices n1 and n2 (n2 > n1) at an angle of incidence q as shown in fig. The angle q is infinitesimally greater than the critical angle for the two media so that total internal reflection takes place. Now if a transparent slab DEFG of uniform thickness and of refractive index n3 is introduced on the interface (as shown in the figure), show that for any value of n3 all light will ultimately be reflected back again into medium II. Consider [1986 - 6 Marks] separately the cases (i)

n3 < n1 and

E

MEDIUM I

(n 3 )

G

F

B

A q

Where should a pin be placed on the optic axis such that its image is formed at the same place? (ii) If the concave part is filled with water of refractive index 4/3, find the distance through which the pin should be moved so that the image of the pin again coincides with the pin. 64. What is the relation between the refractive indices m1 and m2, if the behaviour of light rays is as shown in the figure? [1979] m1

m

m1

m2

m m2

n3 > n1 .

(ii) MEDIUM I (n1 )

D

(i)

65. A pin is placed 10 cm in front of a convex lens of focal length 20 cm, made a material of refractive index 1.5. The surface of the lens farther away from the pin is silvered and has a radius of curvature are of 22 cm. Determine the position of the final image. Is the image real as virtual? [1978]

MEDIUM II

(n 2 )

Topic-4 : Prism and Dispersion of Light 1 1.

MCQs with One Correct Answer

The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if D m is the angle of minimum deviation ? [Main 11 Jan. 2019, I]

Dm

(a)

1.535 1.530

400 500 600 700

n2

l (nm)

1.525 1.520 1.515 1.510

400

500

600

700

l (nm)

WWW.JEEBOOKS.IN

P-257

Ray Optics and Optical Instruments 鼀



 �  矄 ᨨ犨矄 �ᨨ 矄 � 犨  ᨨᆠ �矄 ᆠ   �鼀� �矄 ᆠ ᨨ  ⼄盐�ᆠᨨ    矄   ᨨᆠ  � ᨨ   矄�矄 㜠㝐҈㡰 ҈ ᆠ鼀

㡰



l 鼀㡰

 �  䰘

鼀 ҈

盐ᆠ鼀҈ 

ᆠ㡰 l 鼀㡰

 �  䰘

䰘

鼀







�

 黨졔黨㡰

҈

㡰 �᠀�ᆠ鼀 㡰 �᠀҈ᆠ鼀 ᆠ㡰 �᠀�ᆠ鼀 㡰 �᠀҈ᆠ鼀 㝐ᨨ ᨨᆠ ᨨ鼀�ᆠ�� �矄� ᆠ�  ᨨ �矄矄�矄鼀ᨨ  � 꾀ᔼ   ᆠ��  ᨨ  鼀�ᨨ  �矄鼀�矄Ҙ 泐 � ᆠ�       � q ᨨ    ᆠ 꾀 犨ᨨ盐 �  矄鼀�  ᨨ盐�   ᆠ꾀ᔴᨨ  �矄鼀ᨨ�   ᲼㝐� ҈�桌 꾀

l 鼀㡰

 �  䰘





q

꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� �矄� ᆠ�  ᆠ�  �ᨨ 

⼄盐�� �盐�矄鼀 矄盐 矄鼀� �鼀盐鼀 ��ᨨ  ᔼ   ᆠ��  ᨨ  鼀�ᨨ  �矄鼀�矄       �ᨨ � ᆠ�  ᆠ�矄 ᲼㝐� ҈҈ ҈黨ᔼᔼ桌 㡰 黨 㡰  ᆠ㡰  㡰 � 꾀泐ᨨ �� �矄� ᆠ�    �ᨨ  ᨨ ᨨ  ᆠᨨ �矄鼀ᨨ  �  鼀� 泐ᨨ �� 鼀├矄

 �ᨨ  犨�  � ᆠ�  泐  �鼀 泐  鼀� 泐犨� 矄ᆠᨨ  ᆠᨨ �矄鼀犨� ᲼㝐� 졠 � 꾀�҈҈桌 㡰  㡰 黨 ᆠ㡰  㡰 � ᔼ   �鼀  ᨨ 鼀� �ᨨ ᨨ  ᆠ��  ᨨ �矄矄ᨨ �矄鼀泐�dᨨ�犨矄 ᨨ盐  泐� ᆠ�    �� 矄盐 矄 ��ᨨ ᨨ    �鼀�矄  �䰘黨 ᔼ  ᆠ矄犨 �ᆠ ᨨ   ᨨᨨ犨� ��矄ᆠᨨ矄矄 ᨨ 鼀 �鼀盐鼀ᨨ矄矄�盐ᨨ   ᆠ��  䁸 ᲼㝐� ҈桌 㡰 ҈䰘 㡰 ҈ ᆠ㡰 ҈� 㡰 ҈ 꾀鼀ᨨ �� �矄� ᆠ�   ᨨ鼀�  �aᨨ

 矄� 턼ᨨ ��  � � �盐�矄鼀ᨨ  ᆠ� �   㦨  �� 盐 �ᨨ矄ᨨ�   ᆠ�ᨨ �

 �矄鼀  ᆠ 犨  a 矄鼀� �鼀盐鼀盐ᨨ �   �qᨨ  �矄鼀�矄 ᲼꾀 ҈桌 







㡰

é æ æ ҈ öù q > ᆠᨨ矄 -҈ êҘ矄� ç 꾀 + 矄� -҈ ç ÷ ú è Ҙ ø ûú è ëê

㡰

é æ æ ҈ öù q < ᆠᨨ矄-҈ êҘ矄� ç 꾀 + 矄� -҈ ç ÷ ú è Ҙ ø ûú è ëê

ᆠ㡰

é æ æ ҈ öù q > 矄� -҈ êҘ矄� ç 꾀 - 矄� -҈ ç ÷ ú è Ҙ ø ûú è ëê



é æ æ ҈ öù q < 矄� -҈ êҘ矄� ç 꾀 - 矄� -҈ ç ÷ ú è Ҙ ø ûú è ëê

� 犨   �ᨨ  ��ᨨ  d㡰  �ᨨ � ᆠ�  ᆠ �㡰 ᨨ� �盐�矄鼀�矄矄  泐 ᲼㝐� ҈桌 d

d

㡰

㡰 ᨨ

q





a

d

d

ᆠ㡰

= 

㡰 ҈�

턼 㡰 �

ᆠ㡰 

㡰 ᨨ

㡰 �









WWW.JEEBOOKS.IN

EBD_8341 P-258

9.

Physics

A beam of light consisting of red, green and blue colours is incident on a right-angled prism on face AB. The refractive indices of the material for the above red, green and blue colours are 1.39, 1.44 and 1.47 respectively. A person looking on surface AC of the prism will see [Main Online May 26, 2012] A

(a) are parallel to each other (b) are diverging (c) make an angle 2 [sin–1 (0.72) – 30°] with each other (d) make an angle 2 sin –1 (0.72) with each other 14. A glass prism of refractive index 1.5 is immersed in water (refractive index 4/3). A light beam incident normally on the face AB is totally reflected to reach on the face BC if [1981- 2 Marks] (a) (b)

45°

C (a) no light (b) green and blue colours (c) red and green colours (d) red colour only Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is 60°). In the position of minimum deviation, the angle of refraction [2008] will be (a) 30° for both the colours (b) greater for the violet colour (c) greater for the red colour (d) equal but not 30° for both the colours An equilateral prism is placed on a horizontal surface. A ray PQ is incident onto it. For minimum deviation [2004S]

B

10.

11.

R

Q

sin q >

8 9

A

2 8 < sin q < 3 9

2 3 (d) None of these

(c)

2

B q

sin q
 m 

턼

e ®g



m>m҈  m>m



e ®h



m҈㦨m

和

e ®�



mm҈ m   m>m

ᆠ㡰 꾀鼀� �鼀盐鼀 ��ᨨ  � ᆠ�   ��҈    ᆠ� � � ҈  �矄 ᆠ� �矄盐 ᆠ  泐҈㦨 �҈⏌㡰 㡰 ᨨ �矄�矄鼀 鼀� 泐 矄ᆠᨨ 矄盐 ᆠ 犨� � �ᨨ 矄盐 ᆠ犨    �ᨨ � ᆠ�  ᆠ  �矄矄盐 ᆠ�矄



é ù 꾀 �҈ = 矄� -҈ ê矄� 꾀 ᆠᨨ矄  - ҈ - ᆠᨨ矄 꾀 ú  ë û

҈



꾀 � �矄鼀҈犨�  �  鼀  ᨨ鼀�矄矄ᨨ  ᆠ��  ҈��矄ᆠᨨ鼀�  犨�  ᨨ  � �矄鼀 P鼀  ᨨ鼀�矄矄ᨨ  ᆠ��  ҈䰘ᨨᨨ 盐ᆠ �矄矄�ᨨ 犨� ᨨ盐 ��ᨨ   �ᨨ  �矄鼀P�矄 ᲼҈黨黨㜠㝐├矄桌 㡰 � 㡰  ᆠ㡰  㡰  꾀鼀ᨨ �� ᆠᨨ 矄�矄� �ᨨ  �  盐ᆠᨨᨨ盐矄 �矄� ᆠ�   ᨨ ��   � �矄鼀 ��  ᆠ� � �ᆠ矄ᨨ  鼀�ᨨ  �矄鼀 ᨨ ᨨ �

 盐犨 � 矄҈黨҈ ҈䰘矄ᆠ�泐

�矄鼀犨� ᲼҈黨黨㜠㝐├桌

�矄ᔼᔼ









m

m

ᔴᨨ 矄 







㡰 



҈



㡰 ҈







ᆠ㡰 

҈





㡰 





҈

10 Subjective Problems  犨ᨨ�  �ᆠ�矄鼀矄ᨨ  ᆠ��    ├矄 矄 ᨨ犨 �   ��盐꾀�� 泐矄�├矄  �矄�矄鼀 ᆠAB �  ᲼�㜠㝐├矄桌

� 㡰 矄ᨨ   ᆠᨨᨨ盐 ᨨ鼀 �  盐ᆠᨨᨨ盐矄 㡰 矄ᨨ  盐ᆠᨨᨨ盐 ᨨ鼀   �

ᆠᨨᨨ盐矄 ᆠ㡰 矄  ᆠᨨᨨ盐矄 ᨨ鼀ᨨ  ᨨ  㡰 ᨨ矄 �泐 泐ᆠᨨᨨ盐 ᨨ鼀 ᨨ  犨ᨨᆠᨨᨨ盐矄

�







 









㡰   �ᨨ � ᆠ�  ᆠ矄ᨨ  鼀� 泐 ᨨ鼀   �矄�矄鼀 矄鼀� �鼀盐鼀 ��ᨨ  㡰  ᨨ盐� 犨  � �矄鼀DCE矄 ᨨ盐 ᨨ ᨨ盐 C 矄ᨨ      �  鼀�  泐  矄ᨨ  矄 鼀� �鼀盐鼀 ��ᨨ 

WWW.JEEBOOKS.IN

EBD_8341 P-260

�

Physics

和 ᨨ犨 �   ��盐�矄�矄鼀ᨨ  �º  ᆠ� �   m p =   ᆠ꾀ᔴᨨ  �矄鼀�矄ᆠᨨ 犨�   �  �鼀ᨨ  ᆠ��  m 㦨꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ��  ᨨ 犨 � l㦨�� 鼀 ᨨ   ᆠAB  �ᨨ � ᆠ�  ᆠᨨ º ᲼㜠㝐├矄桌 꾀

º

㡰 ᔴᆠ盐 犨 � l ᨨ犨 �ᆠ 泐矄� ᆠ�    泐 �ᨨ  �  ᆠBC矄矄 ᨨ盐� 犨� ᨨ盐  � � �  ᆠ 㡰 ᨨ�� ᨨ 犨 � l �   �ᨨ � ᆠ�  ᆠ �ᨨ   ᆠAC矄盐ᆠ    ��ᨨ ᨨ 盐ᆠ 泐  ᆠᨨ鼀� �ᨨ ᨨ �矄鼀矄�矄鼀� �鼀盐鼀 䰘 꾀��  � �矄鼀 � 黨 � 㡰ᨨ  ᆠ��    矄 ᨨ  ᆠ��  n҈ n҈n㡰ᆠ鼀  ᨨ�矄 ��ᨨ  ᆠ 矄矄鼀泐�矄� �꾀泐�矄� ᆠ�  ᨨ AB

º

꾀 m =  





m 㦨

ᔴᆠ盐 㡰  �ᨨ 鼀� ᆠ 㡰 鼀� �鼀盐鼀盐ᨨ  �ᆠ├ 矄矄t 矄ᨨ  �  矄�泐ᨨ 鼀� 泐�矄鼀 �鼀盐鼀 꾀�矄鼀ᨨ  ᆠ��  n҈  ᨨ �矄鼀ᨨ  ᆠ� �   n 矄盐ᆠ├ ᨨ�  犨� ᨨ盐 �矄 矄 ᨨ犨  �

��盐  �矄ᨨ  �矄鼀矄矄矄 ᨨ犨 n҈ n   ᨨ  l   犨 �  ᨨ  ��  ᆠᆠᨨ � � ᨨ

n҈ = ҈ +

҈ ´ ҈

l 犨 l �矄� nm ᔴ



n = ҈� +

 

҈ ´ ҈

l ᲼҈黨黨㜠㝐├矄桌



䰘





҈

  �㡰 ᔴᆠ盐  �ᨨ � ᆠ�  ᆠAB ᨨ犨 �ᆠ   泐矄�├矄  ��ᨨ  ᆠ ᆠ��ᆠ � ��㡰 꾀矄矄盐鼀� �n㦨҈�ᆠᆠ盐  �ᨨ � ᆠ�  ᆠ AB ᨨ犨 �ᆠ   ᆠ 泐矄矄矄 ᨨ盐�   ��ᨨ  ᆠ盐 �  ᲼҈黨黨㜠㝐├矄桌  꾀泐ᨨ �� �矄� ᆠ�    �ᨨ  ᨨ ᨨ  ᆠᨨ �矄鼀犨 �ᆠ  矄  �ᨨ   泐鼀�� �ᨨ盐ᨨ  �矄鼀鼀├矄  �ᨨ  犨�  � ᆠ�  泐和 ᨨ犨   鼀� 泐�矄 �ᆠ盐ᨨ  ᆠ ᨨ盐� 犨 �ᆠ �鼀�矄 ᆠᆠ盐  ᆠ��  ᨨ   鼀�ᨨ  �矄鼀 ᲼҈黨䰘桌

҈



   





Topic-5 : Optical Instruments 1 ҈







MCQs with One Correct Answer

鼀� � 泐� �ᨨ犨ᨨ 矄ᆠᨨ犨� 盐 �  ᆠ鼀�矄�␔ �矄  ᨨᆠ � ᨨ �矄泐�ᆠ䁸 ᲼㝐�  ᔼ桌 㡰 ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 ҈ᆠ鼀 ᔼ  犨    鼀� � �ᆠ�ᨨ  ᨨ  䰘� ᨨ鼀  ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨᨨ 盐 �  ҈�鼀鼀  ᨨᆠ�ᨨ ᨨᆠ � �鼀鼀  ᨨᆠ � ᨨ  泐㜠�ᆠ矄 ᨨ盐 ᆠᨨ矄ᨨ ᲼㝐� 䰘 ᔼ桌 㡰 鼀鼀 㡰 ҈鼀鼀 ᆠ㡰 鼀鼀 㡰 鼀鼀 꾀 ᨨ矄ᨨᨨ├矄 �矄 ᨨ  �� ҈鼀犨�  矄ᆠᨨᨨ 鼀� � 泐� �ᨨ犨ᨨ  ᨨ ᨨ矄  矄 ᲼㝐� ҈桌 㡰 �鼀矄 㡰 �鼀矄  ᆠ㡰 ҈�鼀矄 㡰 ҈�鼀矄 

ᨨ 鼀�   ᆠ� �   ᨨ  �矄矄 矄 盐矄� �  � � 鼀�ᆠᨨ矄ᆠᨨ 鼀� �鼀盐鼀 盐鼀 ᨨ   � �矄

�

 

䰘

⼄盐�  ᲼㝐� 졠 � 꾀�҈҈桌 㡰 犨ᨨ 㡰 ᨨ盐 ᆠ㡰  㡰 � 꾀矄ᆠᨨ 矄 ᨨᆠ� 矄ᨨ  ᨨᆠ � ҈�ᆠ鼀   泐�ᆠᨨ  ᨨᆠ � �ᆠ鼀ᔼ �鼀ᨨ犨  �矄 ᆠᨨ ҈├鼀�矄ᨨ矄  ᨨ盐�  �矄矄ᆠᨨ�

ᨨ鼀矄� �  � ᨨ鼀 泐 �鼀�ᨨ  ᨨ犨 �矄q  q�矄ᆠᨨ矄ᨨ ᲼㝐� 졠 � 꾀�҈҈�桌 㡰  㡰 ҈� ᆠ㡰  㡰 ҈ ᔼ ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨ  ᨨᆠ � ᨨ ᨨᆠ�  矄�矄҈ᆠ鼀  ᨨᆠ � ᨨ 泐�ᆠ�矄ᆠ鼀␔ 

ᨨᆠ�矄├҈�ᆠ鼀�  ᨨ ᨨ ᨨᆠ� � �鼀��矄 ᨨ鼀 � � �泐㝐� � 泐� �ᨨ犨ᨨ  ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨ矄 ᨨ盐  ᲼㝐� 졠 � 꾀�҈҈҈桌 㡰  㡰 ҈ ᆠ㡰  㡰 ҈� ᔼ ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨ � 鼀 ��鼀��矄 ᲼和桌 㡰 �盐ᆠ 鼀� � � 㡰 ᆠ 鼀� � � ᆠ㡰 �   鼀� � � 㡰 �盐ᆠ  盐ᆠ

WWW.JEEBOOKS.IN

P-261

Ray Optics and Optical Instruments



 ᨨᆠ � 矄ᨨ  ᨨᆠ�  泐�ᆠᨨ  ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨᆠ鼀 ᆠ鼀矄ᆠ�泐

 �矄 ᆠ犨  ᨨᆠ�  泐�ᆠ�矄 ҈�ᆠ鼀  � �鼀� ᨨ鼀 泐 泐�ᆠ�矄 � � �泐 犨ᨨ 矄矄 �   �矄 ᆠ� ᆠ鼀ᨨ   ᨨᆠ  �鼀�ᨨ 盐ᆠ 泐 ᨨᆠ�鼀矄盐 ᨨ鼀 ᨨᆠ� 矄矄ᆠ�泐 ᲼҈黨黨�和桌 㡰  ҈ 㡰  ҈� ᆠ㡰  ҈ 㡰   3

黨

҈

Numeric Answer

꾀ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨᆠᨨ 矄�矄矄ᨨ  ᨨᆠ� 矄ᨨ ᨨᆠ � ҈ᆠ鼀  泐�ᆠᨨ  ᨨᆠ � �ᆠ鼀 犨� 矄�ᨨ ᨨ ҈ᆠ鼀

 �矄 ᆠ犨  ᨨᆠ  ᨨᆠ� 矄 n 犨 �ᆠ  矄� ᨨ  泐�矄鼀� �鼀盐鼀�矄 ᆠ鼀 

盐ᨨ n �矄힘힘힘힘힘힘 ᲼㝐� 和� ᔼ㡰桌 ᔼ ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨ 鼀� � � �盐�鼀��矄 ᨨ鼀  �矄 ᆠᨨ �ᆠ鼀 ᨨ鼀 泐㜠�ᆠ  ᨨᆠ  � ᨨ �矄ᨨᆠ� 矄�矄҈ᆠ鼀ᔼ  鼀� � �ᆠ�ᨨ �矄 ҈  盐 � ᨨ  鼀�ᆠᨨ矄ᆠᨨ�矄ᆠ鼀 

  ᨨᆠ  �  ᨨ    泐㜠�ᆠ  矄 �  ᆠ鼀㡰 �矄 [Main Sep.04, 2020 (I)] 힘힘힘힘힘힘힘힘힘힘

4

Fill in the Blanks

҈҈ 矄ᨨ� �ᨨ犨ᨨ ᆠᨨ 鼀�ᆠᨨ矄ᆠᨨ�矄 ��    ᨨ  ᨨ�ᆠ鼀�ᆠᨨ矄ᆠᨨᆠ盐矄 犨 � ᨨ ᆠᨨ 矄�矄   犨 � ᨨ �矄� ��  ᲼҈黨黨㜠҈㝐├桌 6

MCQs with One or More than One Correct Answer

҈ 꾀   �矄 ᨨ矄  泐   矄ᨨ ᨨ鼀�ᆠ   ᆠ� � 矄ᆠᨨ � � ᨨᆠ�ᨨ  ᨨᆠ � ҈鼀 

泐�ᆠᨨ  ᨨᆠ � ᆠ鼀 ᲼҈黨黨㜠㝐├矄桌 㡰  �矄 ᆠ犨  ᨨᆠ�  泐�ᆠ �矄҈鼀 㡰  �盐鼀� � �ᆠ�ᨨ ᨨ   �矄 ᆠ㡰 �鼀�ᨨ   �矄�  㡰 ᨨᆠ��矄�   泐�ᆠ ҈ 꾀 矄ᨨ ᨨ鼀�ᆠ矄ᆠᨨ 矄  �盐鼀� � �ᆠ�ᨨ ᨨ 鼀� �盐 � ᨨ �矄 ᨨᆠ矄 矄�ᨨ  犨

 ᨨᆠ�  泐�ᆠ�矄ᆠ鼀   � �鼀� �矄 ᨨ鼀 � � �泐  ᨨᆠ � fᨨ  ᨨᆠ�   ᨨᆠ � fᨨ  泐�ᆠ ᲼҈黨黨㜠㝐├矄桌 㡰 f㦨�ᆠ鼀 fe㦨黨ᆠ鼀 㡰 f㦨�ᆠ鼀 fe㦨҈ᆠ鼀 ᆠ㡰 f㦨䰘ᆠ鼀 fe㦨�ᆠ鼀 㡰 f㦨ᆠ鼀 fe㦨ᆠ鼀

Topic-6 : Miscellaneous (Mixed Concepts) Problems 1 ҈

��ᨨ ᔼ

MCQs with One Correct Answer

꾀�� 泐� �� �矄矄鼀 �盐鼀�矄� ᆠ�  ᨨ �矄矄㜠 ��  ᆠ  �ᨨ � ᆠ�  ᆠq  ᆠ  㡰   矄鼀�  㡰�  矄��矄ᨨ 矄 盐 ᆠ�ᨨ ᨨ q ᨨ  ᆠᨨᆠ矄├ᆠ �矄 ᲼҈҈桌

��ᨨ ᔼᔼ

 



ᔼ 矄�泐

鼀





㡰 ᆠ鼀



ᔼ  矄�泐

ᔼ  矄�泐

 

㡰 矄� ҈ ⏌㡰 㡰 矄� ҈ ҈⏌㡰 ҈ ᆠ㡰 矄�  ҈⏌㡰 㡰 矄� ҈ ҈⏌㡰 꾀ᆠᨨ � �矄 � 犨� 犨 m㦨҈㡰盐ᨨ �� ᨨ �ᆠ鼀꾀ᆠᨨ ᆠ鼀�ᨨ�矄ᆠ ҈�ᆠ鼀ᨨ 犨   �鼀�ᨨ  ᨨᆠᆠ  ᨨᨨ鼀�矄 ᨨ鼀 �ᆠ鼀ᨨ犨 犨 ᨨᆠ � ᨨ   鼀�ᨨ�矄 ᲼�和桌  㡰 ҈�ᆠ鼀

㡰

㡰҈奠 ᔼ  矄�泐

ᆠ㡰

��ᨨ ᔼ

  鼀



㡰

��ᨨ ᔼᔼᔼ

҈�ᆠ鼀

黨 q



꾀�� 鼀�矄� � ᨨ鼀 ��ᨨ ᔼᨨᔼ ��盐㡰 

   ᆠ��  � ��ᨨ 矄ᔼᔼᔼᔼᔼᔼ ᔼ     

   矄ᆠ�泐  �ᨨ � ᆠ�  ᆠq ᨨ犨 �ᆠ   鼀盐矄鼀�矄矄矄 � ���ᨨ ᔼ�矄 ᲼桌

ᆠ㡰 ҈҈ᆠ鼀

m㦨҈

�ᆠ鼀

�ᆠ鼀 㡰 ҈ᆠ鼀 졠



WWW.JEEBOOKS.IN

EBD_8341 P-262



�



䰘

Physics

꾀ᨨ� ᨨᆠ�矄ᆠ  ᆠ ᨨ �矄矄矄 ᨨ  �盐矄ᆠ鼀  ᆠ��  ҈�  �矄 ᆠᨨ �盐 ᲼和桌 �鼀� ᨨ鼀 矄盐 ᆠ�矄 㡰 ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 ҈ᆠ鼀 㡰 黨ᆠ鼀 꾀矄ᨨ盐ᆠ鼀�矄矄ᨨ盐 ᨨ  ⼄盐 ᆠ泐 � 矄� 犨

 ⼄盐 ᆠ泐   �  � 犨�  ⼄盐 ᨨ ᨨᆠ�泐 ᨨ  矄ᨨ盐  �  犨 㦨 ҈� 鼀⏌矄 ᨨᆠ�泐ᨨ  矄ᨨ盐  �  � 㦨鼀⏌矄㡰 ᲼和桌 㡰  㡰 ҈ ᆠ㡰  㡰  꾀鼀ᨨ 犨 ��� �矄� ᆠ�  ᨨ �矄矄��  ᆠ ᨨ鼀�矄矄ᨨ�矄盐ᆠ  � �� 盐矄矄盐 矄ᨨ �   ᆠ�ᨨ  ᆠᨨᨨ矄ᨨ  �� 犨 �ᆠ 犨�ᆠᨨ鼀 ᨨ盐ᨨ� ᲼和桌 㡰 �ᨨᔼ ��ᨨ盐 㡰 꾀ᆠᨨᨨ矄 ᆠ�

ᆠ㡰 Ӹᨨ犨졠 �  㡰 ␔ ���  ␔ �ᆠ  ᨨ  ᨨ    ᨨᨨ犨� � 矄 �ᆠ  矄矄 ᨨ矄 ᨨ  �� �矄矄�ᨨ 䁸  ��ᨨ ᆠ盐盐ᨨ  矄盐 ᆠ矄 ᲼和桌 ᨨ   矄矄矄�� �   ��鼀矄

㡰

҈

ᆠ㡰



2 

҈



㡰



㡰







 =  ᔴ



 =

 



҈�ᆠ鼀



 ᆠ鼀

5 True / False ҈҈ �  矄�泐ᨨ ��  �矄 ᆠ�r ᨨ鼀  �矄ᨨ  ᨨ �ᆠ泐� �ᆠ矄ᨨ盐ᆠ�矄� 矄泐ᨨᨨ�ᨨ ᨨ�r ᲼҈黨҈㜠㝐├矄桌 ҈ 矄� �矄盐 矄 �� �  矄├泐  �泐�矄 ᲼҈黨桌 6

MCQs with One or More than One Correct Answer

҈ �矄矄ᆠ泐� 矄ᨨ ⼄盐 �� 㦨ᆠ鼀 矄鼀  ᆠ��  n㦨҈�ᆠ ᨨ  ᨨ� ᨨ 矄盐 ᆠ 矄矄 ᨨ犨 �  ��盐ᔴ泐� ᔼ 矄 ᨨᆠ泐� ᔼᔼ 矄ᆠᨨ  ᨨ ᆠ泐� ᔼᔼᔼ 矄ᆠᨨ ᆠᨨ   ��ᨨ ᆠ盐盐ᨨ  犨ᨨᆠ盐 ᨨ矄矄鼀 㦨 鼀㡰ᔼ H҈H H    矄ᨨ ᨨ� X ᨨ   ᨨᨨ鼀 ᨨ    ᆠ泐� 矄 矄ᆠ�泐   ᲼꾀 ҈黨桌 ᆠᨨᆠ矄鼀  矄㡰�矄⏌

Integer Value Answer

和盐 �� ᨨ �  矄�泐҈├␔鼀�矄� ᆠ�   ᨨ鼀泐ᨨ   � ᆠᨨ   矄ᨨ  ᨨᆠ � ᆠ鼀ᔼ� ᨨ  �泐 ᨨ矄矄 ᨨ ��  盐 ᨨ   矄  矄矄盐鼀      矄 盐矄� �矄鼀盐ᆠ 矄鼀  �矄 ᨨᆠ �   ��  矄�泐ᨨ �� � ├␔鼀 �矄 ᆠᆠ鼀 ᨨ鼀  矄ᨨ  ᨨ 矄� �矄힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌 4

黨



҈ = ҈

Fill in the Blanks

ᔼ  e    m  矄ᆠ�泐 ᆠ�ᆠ鼀���泐  鼀� �ᆠ鼀��泐ᨨ  矄ᆠ e   m    ᆠᨨ矄ᨨ � � ⼄盐 ��矄 �   鼀 �盐鼀   �   ᨨ  ᆠ�ᨨ ᨨ  鼀 �盐鼀� 鼀矄ᨨ  ᨨ鼀矄 �矄 ᲼҈黨黨㜠҈㝐├桌 꾀矄ᨨ 鼀�ᨨ  ᆠ��  矄 ᨨ犨 �  �� 矄 ᆠ盐 矄盐 ᆠAPBᨨ  �盐矄ᨨ ᆠ盐盐҈ᆠ鼀   矄盐 ᆠCD졠   ᨨ APB�矄� ᨨ  ��  ᨨ CD�矄犨犨�  ᆠ�� �ᆠ矄矄�� �   ��盐 꾀 ᨨᆠO�矄ᆠ  �矄 ᆠᨨ ҈�ᆠ鼀 ᨨ鼀 ᨨ P矄矄 ᨨ犨   �矄 ᆠᨨ   � �鼀�ᨨ O ᨨ鼀P矄 �犨  ᨨ鼀  �矄 ᲼҈黨黨҈㜠㝐├矄桌

㡰 ᆠ鼀 㦨҈㡰黨ᆠ鼀 㡰 >҈ ᆠ㡰 >҈ 㡰 > ҈ 꾀 � ᆠᨨ   矄�矄鼀 ᨨ 犨ᨨ鼀�矄犨�  ᆠ� � �ᆠ矄n҈ n矄矄 ᨨ犨 �  ��盐  �盐矄ᨨ ᆠ盐盐 ᨨ    �� 矄 �ᆠ矄盐 ᆠ⼄盐f�矄  ᨨᆠ  � ᨨ   矄犨  n҈㦨n㦨n  ᨨᆠ � �矄f졔 Df犨  n҈㦨n n㦨n졔Dn꾀矄矄盐鼀� �Dn n҈㡰  ҈n ᆠᨨᆠ矄鼀  矄㡰�矄⏌᲼꾀 ҈黨桌

WWW.JEEBOOKS.IN

P-263

Ray Optics and Optical Instruments

㡰 ᔼ 

 � ᆠ 矄 �矄ᆠ 泐�ᆠ 矄�ᨨ  D 矄 矄 ᨨ犨 �   �� ᲼҈黨黨㜠㝐├矄桌

Df Dn > <     f n

Df Dn 㡰  �ᨨ  犨      鼀� 矄 f n 盐 ᆠ  � � ᨨ  ᆠᨨ  矄盐 ᆠ矄ᆠ 泐ᆠᨨ ᆠ矄盐 ᆠᨨ  矄鼀 �盐矄ᨨ ᆠ盐盐 ᆠ㡰 For n㦨҈�Dn㦨҈ f㦨ᆠ鼀 盐ᨨ Df 犨�ᆠ鼀 ᨨ盐 ᨨ ᨨ  ᆠ�鼀ᆠ㡰 Df Dn < f n

犨ᨨ�  �ᆠ�矄矄ᨨ 矄S҈ S  ᆠ��  㦨҈�㡰 ᨨ ᆠᨨ   ᨨ  �盐矄ᨨ ᆠ盐盐҈ᆠ鼀 泐  ᆠ  犨�    ᆠ盐  矄盐 ᆠ矄   �矄 ᆠ d 矄 矄 ᨨ犨 �   ��盐犨�  � 矄 矄 ᨨ犨 泐  矄  � 㡰��  ␔  ᨨ� 矄ᨨ盐ᆠᨨ �� P�矄ᆠ � 矄�  ᨨ S҈ᨨ �矄 �矄 �矄 ᆠᨨ �ᆠ鼀 ᨨ鼀 ᆠ盐  ᆠ  �� 泐矄鼀 � � ᨨ鼀� ᨨ盐 ᨨᨨ   �矄� 矄� S  �矄 ᆠ �矄 ᲼꾀 ҈�桌

㡰 ҈�



�ᆠ鼀

҈

S

P d

㡰 ᆠ鼀 㡰 䰘ᆠ鼀 ᆠ㡰 ᆠ鼀 㡰 黨ᆠ鼀 꾀泐졠ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� �矄� ᆠ�  ᨨ   ᆠ 꾀ᨨ �矄鼀꾀ᔴ   � ᆠ�   �ᨨ   矄 ��盐㡰ᔼ   ᆠ��  ᨨ  鼀�ᨨ   �矄鼀�矄  犨 �ᆠ ᨨ   ᨨᨨ犨� ��矄 㡰ᆠᨨᆠ䁸᲼҈桌

҈䰘

҈

㡰 泐�矄ᨨ泐�  泐 ᆠ  ᆠᔴ 㡰 泐ᆠᨨ鼀矄ᨨ盐 ᨨ盐�  ᆠ꾀 ᆠ㡰  �犨  � ᆠ�  泐  鼀�  泐�矄黨 㡰  �犨  � ᆠ�  泐  鼀�  泐�矄҈ 꾀ᆠᨨ ᆠ鼀�ᨨ�矄ᆠ ᨨ  ᨨ� ᨨ 犨� �矄  �矄 �ᆠ �ᆠ泐盐犨 矄O ᨨᨨ   鼀�ᨨ ᔴ�矄ᆠ ᨨ ᆠ盐盐꾀ᨨ� ᨨᆠ�矄ᆠ Cᔼ 矄�鼀�矄ᨨᨨᆠ Cᔼ  鼀�ᨨ�矄

ᨨ犨 � 犨� 犨 �鼀�犨�᲼҈黨黨㜠㝐├矄桌 㡰  犨�鼀� C 㡰  ᨨᆠ ᨨ� 犨 C  ¥  ᆠ㡰 �盐 ᨨᆠ ᨨ� 犨 C O 㡰  ᨨᆠ ᨨ� 犨 C O

犨ᨨ  �  ᆠᨨ    矄矄ᨨ  ᨨᆠ  � 矄 f҈   f  矄 泐 ᨨ� ᨨ  �矄 ᆠ  犨 df҈ f㡰

泐 D







├� � ᨨ��� ᨨ ᆠᨨᨨ � 矄O ᆠ ᨨ   �矄  矄   泐ᆠᨨᨨ � 矄ᨨ   ᨨᆠᨨ� ᨨ  �矄 矄 矄泐矄鼀 ᨨ鼀ᨨ 泐矄ᆠᨨ鼀� � ᨨ鼀   �� 泐 f҈ f  y= D f҈ + f 

㡰

x=

㡰

f f + d㡰 D x= ҈  y= f҈ + f - d f҈ + f

ᆠ㡰

x=



f f + d f҈ - d 㡰 y =  x= ҈  f҈ + f - d

f҈ f  + d f҈ - d 㡰 D f҈ - d 㡰 y= f҈ + f  - d f҈ + f - d

Comprehension/Passage Based Questions

8

꾀和和꾀෌E 㝐ᨨ矄鼀�矄   ᆠ��  n>҈和ᨨ犨   �� 泐 ᨨ鼀� 矄 盐泐ᨨᆠᆠ盐� �鼀� 

sin q҈ n  ��矄盐 矄ᨨᨨ    = 泐和 矄犨 sin q n҈  ᆠ  泐  矄 ᨨ犨 矄   ᨨ鼀 盐 �  鼀�矄ᨨ  矄鼀矄� ᨨ   ᨨ鼀矄 � ᆠ�  泐 꾀ᆠᆠᨨ � �ᨨᆠᨨ鼀� �矄鼀  ᆠ��  ᨨ   鼀 �盐鼀 �矄 ��  泐   �ᨨ 

㦨c/ v = ± er mr  犨 c�矄 矄 ᨨ ᆠᨨ鼀� �ᆠ 犨矄� ᆠ盐盐鼀v�矄矄 �  鼀 �盐鼀er mr  �鼀���泐 鼀��泐ᨨ  鼀 �盐鼀 矄ᆠ�泐 ᔼ  ᨨ鼀鼀�矄ᨨ  e r   mr ᨨ矄���鼀泐� � ᨨ矄��n ᨨ  鼀 �盐鼀 ␔   ᨨ  e r   mr 

�� ᨨ 鼀盐矄ᆠ ᨨᨨ矄  ��ᨨᨨᨨ  n 和盐ᆠ

�� ᆠ��  鼀�矄ᆠ  ᨨ犨� �ᆠ�泐      ᆠ  鼀㜠鼀�矄 泐 �� 矄�� � �ᆠ 泐 �  ᨨ�ᆠ �ᨨ犨� ᨨ盐�ᨨ� �  泐 泐矄�ᆠ犨矄和� ᆠn�矄 ���矄盐矄� ᆠ  � �    �ᆠ�ᨨ  ᨨ  ᨨ��ᨨ  ᨨ     ᆠ  ��  ᨨ犨矄�鼀�ᨨ ᨨ鼀鼀�矄  ⼄盐 ᆠ泐ᨨ ��  鼀� 矄盐 ᆠ  � 盐ᨨ  ᆠ�ᨨ  � 鼀㜠鼀�矄 ᲼҈桌 ҈黨 ᨨ ��  � ᆠ�   ᨨ鼀 � ᨨ   鼀㜠鼀�   ᨨ�泐 ��鼀�矄 

q1

㡰

Air

㡰

Meta㜠material q2

WWW.JEEBOOKS.IN

EBD_8341 P-264

Physics 



q1

ᆠ㡰

Air



Meta㜠material

Air

Meta㜠material q

q2



ᔴ ᨨᨨ矄 ᆠᨨᆠ矄鼀  㡰 矄 ᨨ �� �  鼀㜠鼀��矄v㦨cn 㡰 矄 ᨨ �� �  鼀㜠鼀��矄v㦨

c

n ᆠ㡰 矄 ᨨ �� �  鼀㜠鼀��矄v㦨c 㡰 犨 � ᨨ  �� �  鼀㜠鼀� lm㡰 �矄�� 泐lm㦨l�n犨 l��矄犨 � ᨨ  �� � �

10 Subjective Problems ҈

꾀 泐 �矄 � ᆠ�   ᨨ   鼀 �盐鼀 ᆠᨨ 矄�矄� � ᨨ  犨ᨨ ᨨ盐 �矄ᨨ   ᨨ ᆠ盐 矄矄 ᨨ犨 �   ��盐  矄盐 ᆠ鼀├矄  �º犨�  ᨨ� ᨨ    ᆠ盐  矄盐 ᆠ 矄  �盐矄 ᨨ  ᆠ盐盐  鼀   ᆠ�� �ᆠ矄ᨨ  鼀 �盐鼀 �矄 �ᨨ 鼀  矄 ᨨ犨 �   ��盐ᔼ   ᆠ�ᨨ ᨨ  矄盐 ᆠ矄  泐鼀矄� ᆠ� �矄P � OP᲼㜠㝐├矄桌

㦨Ö

�º



㦨҈



㦨҈�҈

º



�   ᨨᆠ � ᨨ   矄矄 ᨨ犨 �   ��盐   ��ᨨ ᆠ盐盐ᨨ ᨨ  矄盐 ᆠ矄⼄盐ᨨR ᲼㜠㝐├矄桌 m҈ < m  < m  m҈

m

m

  ᆠ�� �ᆠ矄ᨨ  ᆠᨨ犨 �矄矄 ᨨ盐  �� 矄҈�҈ ҈黨矄ᆠ�泐  ᨨ矄ᨨ  � �矄矄 ҈䰘䰘 ҈䰘矄ᆠ�泐꾀 �矄ᨨ矄ᆠ矄�矄鼀ᨨ  � ᨨ�矄鼀 ᨨ ᆠᨨ犨 �矄矄꾀鼀ᨨ 犨 ��� �矄� ᆠ�   矄鼀 �ᨨ  �矄�矄鼀 ᨨ  � �矄矄�矄ᨨ矄ᆠ矄 �矄鼀�矄ᆠᨨ鼀�  犨�  ᆠᨨ犨 �矄矄�矄鼀矄盐ᆠ    �矄 ᨨ ��ᨨ ᨨ  � ᆠ�  ��  㡰鼀�    �ᨨ   � �矄矄�矄鼀 㡰ᔴᆠ盐   �矄矄�ᨨ ᨨ  ᆠᨨ鼀�  矄泐矄鼀 ᲼҈㜠�㝐├矄桌 � 꾀泐ᨨ �� � �� ��矄� ᆠ�  � � � � � ᆠ�   � @ 黨° 㡰ᨨ ᨨ �ᆠ �盐矄ᨨ   矄 鼀 �盐鼀ᨨ  �ᆠ├ 矄矄㦨҈鼀 矄 ��盐ᨨ犨㡰

 ᨨ�  ᨨ 泐 � ᆠ�  ᆠ�矄 ᨨ���

A 㡰 鼀 �盐鼀  ҈  泐҈ 㡰 꾀ᔼ 矄��  ᨨ  ᆠ�ᨨ  n y㡰 ��

 = ҈鼀  泐㡰 泐 n y 㡰 = ᲼ky ⏌  + ҈桌҈⏌  

꾀 � �ᆠᨨ   矄ᨨ  ᆠ��  ⏌�矄ᆠ ᨨ  ᨨ� ᨨ  鼀�ᨨ矄矄 ᨨ犨 �   ��盐 矄ᆠ 犨   矄  鼀�ᨨ�矄   � 犨� 犨ᨨ  ᆠ��  ⏌ᔼ�矄 ᨨ盐  犨  ᨨ� ᨨᆠ�矄 ᆠ ҈�ᆠ鼀ᨨ  矄ᨨ �矄� ᆠ� �矄 ᨨᆠ ᆠᨨ� ᆠ� 矄犨� �矄ᨨ犨 �鼀�졠 � �犨�  ᨨ  �⼄盐�  ᨨᆠ  �鼀��� ᆠᨨ� ᆠ�  �矄 ᆠ �ᆠ鼀 ᨨ鼀  矄ᔴᆠ盐  ᆠ��  ᨨ   ᲼҈㜠�㝐├矄桌 �⼄盐�  

꾀 㡰

꾀ᔼ



犨 ├㦨҈ 鼀㡰 - ⏌ 

 ᆠ��  ᨨ ��矄҈ ᲼҈黨黨�㜠҈㝐├矄桌 㡰 졠� �ᨨ 犨  矄ᨨᨨ  ᆠᨨ泐 ᨨ  泐� B xy㡰�  鼀 �盐鼀   � ᆠ�   � ᨨ�  㡰 졠�  ⼄盐�ᨨ  ᨨ ᆠᨨ泐y x㡰ᨨ  泐�

 鼀 �盐鼀 ᆠ㡰 鼀�  ᆠᨨᨨ � 矄 x҈  y҈ 㡰 ᨨ  ᨨ� P 犨  泐� 矄ᆠ矄 盐矄盐 ᆠᨨ  矄㜠 �ᨨ盐 泐 㡰 ᔼ �ᆠ  ᨨ  泐矄盐矄⼄盐 泐  犨ᨨ  鼀矄 ᨨ  ��  P   Q 矄�ᨨ  㡰 ᆠᨨ � � � ��ᨨ 矄ᨨ 犨 � 矄处 �处 犨 �ᆠ   鼀盐盐泐 ᆠᨨ   �  ᆠ  犨 � 矄泐㡰� ᆠ�   ᨨ鼀泐ᨨ �矄鼀矄矄 ᨨ犨 �

��  ᆠ��  ᨨ  �矄鼀矄 盐 ᆠ�ᨨ ᨨ  犨 � �矄�� 泐 �ᨨ  m l㡰 㦨҈졔  l 犨  l �矄� 处 b�矄ᨨ矄��ᆠᨨ 矄  盐ᨨ b �矄矄盐ᆠ   ᆠᨨ ��ᨨ  ᨨᨨ ᆠ�ᨨ ᨨ   ᆠ AC�矄盐矄矄�矄 �  ᨨᨨ 犨 �  �矄 ᨨ矄�矄 � ᨨ ᨨ  ᲼҈黨黨҈㜠졔졔㝐├矄桌 꾀 q





㝐쟼ᔼ㝐

矄� q = 

黨







㡰 �  盐ᨨ b 㡰 �   ��ᨨ ᨨ  鼀矄 矄鼀�  ᨨ盐�   ᆠAC ᆠ㡰 꾀ᆠᨨ �  矄�矄盐矄 ᨨ� � 矄 矄鼀� 鼀矄 � ᨨ ᨨᆠ盐矄 ᔼ   �  矄��矄 ᨨ   矄鼀�矄矄�ᨨ

ᨨ鼀  ᆠAC҈ I矄ᆠ�泐 �   矄盐 �  矄�泐  ᨨᆠ盐矄

WWW.JEEBOOKS.IN

P-265

Ray Optics and Optical Instruments

和ᆠ 和�矄�盐鼀�  泐犨ᨨᨨ� 矄ᨨ盐ᆠ矄A   B 꾀 ᨨ 矄ᨨ盐ᆠC矄 矄鼀ᨨ �� ᨨ犨 矄 ᨨ� Pᨨ  矄ᆠ  矄 ��盐㡰� AP�矄 ᨨ鼀ᨨ  矄ᆠ   � 矄APBP  CP� ᨨ    �矄 ᆠAPBP CP鼀҈�鼀 ҈�鼀 矄ᆠ�泐  �  C ᨨ犨矄ᨨ 矄ᨨ盐ᆠ矄A B黨犨矄 ҈ 犨矄 矄ᆠ�泐  鼀  ᨨ鼀  ᔴ �矄 ᨨ 60° P �  矄�泐 犨矄⏌鼀 A× 60° ᔴᆠ盐 �  矄�泐 Pᨨ  矄ᆠ  ᲼҈黨㜠�㝐├矄桌

䰘

B

 꾀 ᨨᆠ�矄ᆠ ҈ᆠ鼀�  ᨨ ᨨ ᆠᨨ ᆠ鼀�ᨨᨨ  �盐矄ᨨ ᆠ盐盐҈ᆠ鼀꾀�矄矄矄ᨨ  �ᆠ├ 矄矄ᆠ鼀   ᆠ��  ҈��矄  ᆠ ᆠᨨ矄ᨨ 鼀�ᨨ�

 矄ᆠ犨  ᨨᆠ  鼀�ᨨ �  ᨨ矄��ᨨ ᨨ   � �鼀� ᨨ鼀  Ӹᨨ盐鼀泐 ├  �矄 ᆠᨨ   矄盐 ᆠᨨ  矄 ᨨ鼀  鼀�ᨨᨨ҈ᆠ鼀 ᲼҈黨桌 黨 꾀ᆠ �盐ᨨᆠ├ᨨ �矄矄�矄ᆠ ᨨ �  � 泐� �ᨨ  ᨨ� ᨨ 矄盐 ᆠ �  鼀� �鼀盐鼀盐ᨨ   ᆠ��  ᨨ �矄矄 ᨨ犨 �ᆠ  矄ᨨ   � ᨨ�矄� ᨨ鼀 泐ᨨ  �ᆠ ᆠ矄ᨨ   ᲼҈黨䰘黨桌 ᨨᆠ├

S

Answer Key Topic-1 : Plane Mirror, Spherical Mirror and Reflection of Light ҈ 㡰 ҈҈ 㡰

 ᆠ㡰 ҈ 㡰

 ᆠ㡰 ҈ ҈㡰

 㡰 � ᆠ㡰 ҈ ҈�㡰 ҈� 㡰

 ᆠ㡰 䰘 ᆠ㡰 ҈ ᆠ 㡰 ҈䰘 ᆠ㡰

 㡰

黨 㡰

҈ 㡰

Topic-2 : Refraction of Light at Plane Surface and Total Internal Reflection ҈ ҈҈ ҈ 

㡰  ᆠ㡰 㡰 ҈ ᆠ㡰 㡰  㡰 处�맔҈҈ 㡰

 ҈  ҈

㡰  ᆠ㡰 � 㡰  ᆠ㡰 ҈ 㡰 ҈� 㡰 ҈ 㡰  㡰 � 㡰  맔҈鼀⏌矄맔҈䰘鼀㡰  ᆠ 㡰 

㡰 䰘 ᆠ㡰 㡰 ҈䰘 㡰 ҈�㡰 䰘 黨㡰 ᆠ 㡰  ᆠ㡰

 ҈  �

㡰 㡰 �㡰 㡰

黨 㡰 ҈ ᆠ㡰 ҈黨 㡰  㡰 黨 处㡰

Topic-3 : Refraction at Curved Surface Lenses and Power of Lens ҈ ҈҈ ҈ ҈ ҈ � �

㡰  㡰  㡰  㡰 ҈ 㡰 ҈ 㡰 ҈ 㡰  㡰  ᆠ㡰  㡰  㡰  㡰  㡰  ҈�鼀�鼀㡰  㡰 �҈ ᆠ㡰 �  㡰 � 꾀㜠⼄矄錐㜠⼄錐ᔴ㜠⼄矄錐㜠⼄矄

㡰 � 㡰 ҈� 㡰 � 㡰 � ᆠ鼀㡰  㡰 �

㡰  㡰 ҈ ᆠ㡰  㡰  ҈�ᆠ鼀㡰 � 㡰 ��

㡰 䰘 㡰  ᨨ盐 矄㡰 黨 㡰 ҈䰘 㡰 ҈ 㡰 ҈黨 ᆠ㡰 䰘 㡰  㡰 黨 ᆠ㡰 䰘 ᆠ㡰  䰘㡰 黨

盐錐  矄錐 䰘  㡰  꾀㜠錐㜠⼄矄錐ᔴ㜠㜠⼄矄

ᆠ㡰 ҈ 㡰  㡰  㡰   㡰 黨

㡰 㡰 ᆠ㡰 䰘҈黨㡰 㡰

Topic-4 : Prism and Dispersion of Light ҈ 㡰 ҈҈ 㡰 ҈ ᆠ㡰

 ᆠ㡰 ҈ ᆠ㡰  㡰

 ᆠ㡰 ҈ ᆠ㡰  㡰

 ᆠ㡰 ҈ 㡰

� 㡰 ҈� 㡰

 ᆠ㡰 ҈ ҈�㡰

䰘 ᆠ㡰 ҈䰘 ҈� 㡰

 ᆠ㡰 ҈  㡰

黨 㡰 ҈ 㡰 ҈黨 盐錐 ᆠ 㡰

 㡰

黨 �㡰 ҈ 㡰

Topic-5 : Optical Instruments ҈ 㡰  㡰  㡰 ҈҈ 矄鼀㡰҈ ᆠ 㡰 ҈ 㡰

 ᆠ㡰

� ᆠ㡰

 㡰

䰘 ᆠ㡰

Topic-6 : Miscellaneous (Mixed Concepts) Problems

҈ ᆠ㡰

 㡰

҈ ᆠ鼀㡰 ҈҈ 盐錐  㡰

 ᆠ㡰 ҈ 盐錐

 㡰

� ᆠ㡰

 ᆠ㡰

҈  㡰 ҈ ᆠ㡰҈� 㡰

䰘 ᆠ㡰

 ҈㡰

҈ ᆠ㡰҈䰘 㡰

黨

me 㡰 me

҈ ᆠ㡰

҈黨 ᆠ㡰

WWW.JEEBOOKS.IN

EBD_8341 P-266

Physics

Wave Optics

24

Topic-1 : Wavefront, Interference of Light, Coherent and Incoherent Sources 1 ҈

MCQs with One Correct Answer

ᔼ    ��盐 ᨨ犨    턼  犨ᨨ ⼄盐泐 �  矄 ᆠᨨ  矄ᨨ盐ᆠ矄鼀�� � ��ᨨ ᨨ 犨 � 鼀

矄�ᨨ 犨  턼�矄�鼀   矄ᨨ  �矄  ᨨ  ᨨ 턼泐黨º꾀 ᔴ  �矄� ᆠ ᨨ� 矄ᨨ ᨨ矄�ᨨ ᆠ ⼄盐� �矄  ᨨ鼀 鼀� ᨨ�  ᨨ 턼 �  矄��矄ᨨ  ��ᨨ 꾀ᔴ犨��   �ᨨ ᲼㝐� 和 ᔼ㡰桌

 p æ L L҈ ö p æ L҈ L ö 㡰 ç - ÷ ç - ÷ l è n҈ n ø l è n҈ n ø p p n L҈ - n҈ L 㡰 n҈ L҈ - n L 㡰 㡰 ᆠ㡰 l l 꾀鼀ᨨ �� 矄�├矄�ᆠᨨ  矄 �矄矄 � �ᆠᨨ矄矄矄ᆠ�ᨨ 矄矄 ᨨ犨 �   ��盐ᨨ犨ᔴᨨᆠ 矄  ᨨ    鼀�  犨 ᨨ  犨�  ��盐矄  矄ᆠ 鼀�ᆠ  ᨨ 犨 ᨨ矄ᆠ㡰 ᲼꾀 桌

㡰





Glass

L�ght





ᔴ



㡰 �

鼀

S ҈�鼀

鼀

L



d





꾀�

꾀�

꾀

㡰 ҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈

犨ᨨᆠᨨ  矄ᨨ盐ᆠ矄ᨨ 矄ᨨ盐 S҈ Sᨨ 盐ᆠ矄ᨨ盐 犨矄ᨨ  矄鼀犨 � l㦨҈鼀�  矄S҈ S ᆠ ҈�鼀 矄 ��㡰꾀�矄 ᨨᆠ L �ᆠ泐�  ᨨ ᨨ S � 矄  �  矄�泐�矄鼀� �鼀盐鼀 犨   �矄鼀犨泐 ᨨ鼀S �矄 鼀ᨨ矄犨泐 ᨨ鼀S҈├� � �矄 �矄 ᆠ ᨨ鼀S �    ᆠ  鼀 �鼀盐鼀ᨨ �  矄�泐�矄ᨨ矄 犨   �矄 �矄 �矄 ᆠd ᨨ鼀S҈  d�矄 ᲼㝐� 和� ᔼᔼ㡰桌

㡰 ҈鼀 㡰 �鼀 ᆠ㡰 鼀 㡰 鼀

犨ᨨ�� 犨矄 � � 矄鼀犨 � l� ᆠ盐盐鼀 �  矄� ��泐    �矄犨矄 L҈  ᨨ盐� 鼀 �盐鼀ᨨ  ᆠ��  n҈犨 � 矄ᆠᨨ 犨矄  ᨨ  �  L  ᨨ盐�  鼀 �盐鼀 ᨨ  ᆠ��  n꾀  �矄  矄 �  ᆠ犨

 犨ᨨ犨矄�矄 ᲼㝐� 和 ᔼᔼ㡰桌

䰘

㡰

ᆠ㡰



ᔼ  �   ᆠ �鼀  �ᨨᨨ 鼀�盐 矄ᨨ a҈ ҈ ᆠᨨ  犨矄�矄 a =   �ᨨᨨ 鼀 �鼀盐鼀  鼀� �鼀盐鼀�  矄��矄ᨨ  � �矄犨� ᲼㝐� 꾀�҈黨ᔼ桌 㡰  㡰 ҈ ᆠ㡰  㡰 黨

犨ᨨᆠᨨ  矄ᨨ盐ᆠ矄ᨨ 盐ᆠ犨矄ᨨ  �  �  矄��矄 犨 �ᆠ �  꾀 �   ᆠ �ᨨᨨ  鼀 �鼀盐鼀 �  矄�泐ᨨ 鼀� �鼀盐鼀�  矄�泐�矄҈ �  矄�泐ᨨ   犨矄�  �ᨨ ᲼㝐� 黨 ҈黨ᔼ桌 㡰 ҈黨 㡰 �黨 ᆠ㡰 ҈ 㡰 � 졠  ᨨ矄盐鼀鼀 ��   ᆠ��  ᨨ ��矄矄鼀矄

 �ᨨ盐  � ᆠ矄矄犨�  ��  ᨨ鼀 �ᨨ盐  ␔  �� 鼀�矄 �ᆠ  ᨨ� ᨨ 泐 盐泐� 矄Ἐ � ᆠ� 矄盐矄ᨨᆠᨨ ᆠ盐  矄�矄 ��  鼀  ᲼㝐� ҈�桌 㡰  矄 ᨨ犨 犨 矄 㡰  矄 盐犨 矄 ᆠ㡰 ᆠᨨ鼀矄 ᨨ犨 㡰 �ᨨ矄 ᨨ� ᨨ 泐犨� ᨨ盐 泐  ᆠ�ᨨ

WWW.JEEBOOKS.IN

P-267

Wave Optics



ᔼ   ᆠ   �矄 ᨨ矄   � 盐 ᨨ 矄盐�鼀ᨨ矄��ᨨ ᨨ 犨ᨨ泐矄ᆠᨨ鼀� �ᨨ盐 ᨨ鼀矄ᨨ盐ᆠ�和 矄矄 ᨨ犨 �   ��盐 盐ᨨ � ᨨ犨 �ᆠ 鼀 �鼀�矄 ᨨ�  ��矄 ᲼㝐� 졠 � 꾀�҈҈桌 �矄 ᆠ ᆠ� �矄盐 ᆠ㡰 ҈







㡰  = ᆠ㡰

黨

=

 l  -҈ (  - ҈) l 

(

 - 

)



㡰

=

(  - ҈) l 

㡰  =

(

)

 -҈

(  - ҈) l

 -҈ ᔼ   ᆠ  ��鼀 CP矄 矄犨 ᨨ  AO BP ᆠᨨ矄ᨨ � �犨ᨨ泐矄 �  ᆠᨨ ��ᨨ

ᨨ  q ᨨᆠᨨ 矄盐ᆠ��   ᆠ犨  泐BP   ᆠ 泐OP ᲼和桌 턼

졠



㡰 ᆠᨨ矄 q 㦨 l ⏌d ᔴ

㡰 ᆠᨨ矄 q 㦨 l ⏌d



ᆠ㡰 矄ᆠ q ᆠᨨ矄 q 㦨 l ⏌d

꾀 

㡰 矄ᆠ q ᆠᨨ矄 q 㦨 l ⏌d 

҈

҈҈

҈

犨ᨨ鼀矄ᨨ ��  � ��  矄��矄I  I �  ᨨ ᨨ 盐ᆠ � � ᨨ 矄ᆠ   矄 �  ᆠ 犨  鼀矄�矄p⏌ᨨ� A pᨨ� B

   �  ᆠ犨  矄盐 �  矄��矄 A B �矄 ᲼҈和桌 㡰 I 㡰 I ᆠ㡰 �I 㡰 䰘I 꾀 � 矄�ᆠ�矄ᆠ盐ᨨ盐ᨨ �矄矄ᆠ泐� ᨨ �  ᨨ�矄 �矄 矄�ᆠ�矄ᆠ ᨨ  �矄矄 矄矄 ᨨ犨 �  ��盐

ᨨ矄 �   ᆠ � �矄 ᨨ鼀 �矄ᆠᨨ鼀� �ᨨ

矄  ᲼҈黨黨黨和㜠㝐├矄桌 㡰 矄��  㡰 ᆠ�ᆠ盐 ᆠ㡰 ⼄盐泐矄ᆠ 㡰 � � � � 矄ᆠ� � 犨 �ᆠ  � ᆠ矄矄 矄 犨 �ᨨ ᨨ盐犨 矄

犨ᨨᆠᨨ  鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� 鼀矄ᨨ �  矄��矄I  I矄盐ᨨ矄  鼀 �鼀盐鼀 鼀� �鼀盐鼀ᨨ矄矄� �  矄��矄�  矄盐� �鼀 ᲼҈黨㜠҈㝐├桌 㡰 �I I 㡰 �I I ᆠ㡰 黨I I 㡰 黨I I

6

MCQs with One or More than One Correct Answer

҈ 犨ᨨᆠᨨ  鼀ᨨ ᨨᆠ ᨨ鼀�ᆠᨨ� 矄ᨨ盐ᆠ矄和҈ 和ᨨ 犨 � l㦨 鼀ᆠ 矄泐鼀鼀�ᆠ泐ᨨ �  矄� ᨨ  ᆠ ᨨ  ᆠ�ᆠ矄矄 ᨨ犨  矄ᨨ盐ᆠ矄 矄 泐 �矄 ᆠ 㦨҈鼀鼀 �矄 �鼀  ᨨ 盐ᆠ矄�   ᆠ � �矄�矄�矄 ��    ├ 矄ᨨ矄ᨨ   ᆠ�ᆠ盐鼀  ᆠᨨ  ᆠ�ᆠ   �盐矄�ᨨ 犨 犨ᨨᆠᨨ 矄ᆠ盐��� 矄ᨨ矄 �矄Dq␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨ�ᨨ 矄�矄⏌ᆠᨨᆠ䁸 ᲼꾀 ҈䰘桌 ҈ 㡰 꾀 ├ 矄ᨨ 犨�  ᨨ鼀  ᨨ�  Dq 㡰 꾀 ᨨ ᨨ   � �犨�鼀 �鼀盐鼀  ᆠ㡰  ᨨ 盐鼀 ᨨ 和҈ 和 � �矄ᨨ 盐ᆠ 犨

 ҈      �    �矄 ⼄盐  �矄ᆠᨨ矄ᨨ 㡰  �盐 矄�ᨨ  犨  犨ᨨᆠᨨ 矄ᆠ盐� ��  矄ᨨ矄  ᆠ矄矄 矄 犨 鼀ᨨ  ᨨ鼀 ҈ ᨨ  ᨨ �  �矄⼄盐   10 Subjective Problems ҈ 꾀ᨨ� 矄ᨨ盐ᆠS鼀�� ��� ᨨ 犨 �  鼀�矄 ᆠ   泐矄鼀 ��   ᨨ   ᆠ� � 矄盐 ᆠAB 矄 ��盐㡰 �  矄�泐ᨨ   ᆠ ��  �矄奠ᨨ  � ᆠ�  �  矄�泐ᔼ   ᆠ � �矄 ᨨ矄  ᨨ   矄ᆠ  ᆠ   ᨨ    ᆠ� � 矄盐 ᆠ泐� �矄 ᆠD ᨨ鼀�᲼㜠�㝐├矄桌  㡰 ␔ �矄 矄 ᨨ   和ᆠ

�   ᆠ � �矄ᨨ

 矄ᆠ 䁸 㡰 ᔴᆠ盐   �ᨨ ᨨ    鼀� �鼀盐鼀 ᨨ   鼀 �鼀盐鼀�  矄��矄�

 �   ᆠ � �矄 ᨨ鼀   ᨨ� P 和 꾀  矄 ᨨ犨 �   ��盐㡰 ᆠ㡰 ᔼ  �  矄�泐ᨨ� Pᆠᨨ矄ᨨ 矄ᨨ鼀 �鼀盐鼀 ᆠᆠ盐 鼀� �鼀盐鼀 �矄 ᆠ ᨨ盐� 犨 �ᆠ    ᆠ� �矄盐 ᆠAB矄 ᨨ盐 矄 �  矄ᨨ   �  矄�泐P�� ᆠᨨ鼀矄鼀 �鼀盐鼀 ҈� 꾀 ᨨ犨鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ鼀ᨨ �� ᨨ  ෌矄矄  �  矄�泐ᔼ �矄 � ᆠ�   ᨨ   �矄矄  矄 矄 ᨨ犨 �  ��盐꾀 ᨨ �  �ᆠ�矄矄 ᔼ �矄├ᆠᨨ矄ᨨ  �矄ᨨ  ᨨ �쟼ᆠ �矄矄 ᆠ矄�ᆠ ᨨ   ��  � ᆠ�    ᨨ  �    矄鼀�矄   鼀� � � �  �ᨨᨨ  鼀� �鼀盐鼀 ෌矄矄   鼀 �鼀盐鼀�  矄��矄�  �   ᆠ   ᨨ鼀 泐 犨ᨨ鼀矄ᨨ�   ᨨ  ᆠ�ᨨ ᆠ  ᲼҈黨黨㜠䰘㝐├桌

Topic-2 : Young's Double Slit Experiment 1 ҈

MCQs with One Correct Answer

ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 �� ᨨ � 鼀�矄盐矄 ᨨ ᨨ 盐ᆠ   �   ᆠ   ␔     �矄 ᆠ

犨  矄�矄�矄�鼀鼀  �盐犨�   �  �㡰 ᨨ   � �矄 ᨨ鼀 ᨨ   �矄 ᆠ矄ᆠ �矄ᆠᨨ矄ᨨ 㡰 ҈䰘

㡰 �䰘

[Main Sep. 03, 2020 (I)] ᆠ㡰 ҈䰘 㡰 䰘

WWW.JEEBOOKS.IN

EBD_8341 P-268







�



䰘

ᔼ   ᆠ � �矄  ᨨ矄  ᨨ   矄ᆠ  泐 �盐鼀� � �犨ᨨ � 矄�矄҈鼀鼀犨� �� 矄ᨨ盐ᆠ l 㦨 鼀㡰  �矄 ᆠ犨  矄ᆠ   矄�矄 �矄҈ᆠ鼀ᔼ ��  � ��矄ᨨ矄 ᨨ 矄ᆠ  �矄 ᆠᨨ ҈䰘鼀鼀 ᨨ鼀 ᆠ ��  � �      �  ᆠ犨   犨矄 犨 �ᆠ ᆠ � �  �矄ᨨ�  ᨨ鼀 矄�矄�矄ᆠᨨ矄ᨨ [Main Sep.02, 2020 (I)] 㡰 ҈䰘m鼀 㡰 䰘 鼀 ᆠ㡰  鼀 㡰 �m鼀 ᔼ Ӹᨨ盐 �Ἐ矄 ᨨ盐矄� �鼀 ҈ � �矄ᨨ矄 � ᆠ� 矄�鼀 ᨨ  矄ᆠ 犨  �� ᨨ 犨 � 䰘 鼀�矄盐矄 ᔼ  犨 � ᨨ �� �矄ᆠ  � ᨨ  鼀   盐鼀 ᨨ  � �矄ᨨ矄  �    矄鼀 矄�鼀 ᨨ  矄ᆠ 犨ᨨ盐  [Main Sep.02, 2020 (II)] 㡰  㡰  ᆠ㡰 ҈ 㡰  ᔼ  ᨨ盐㜠矄� �鼀 ᆠ� ᨨ� ᨨ  矄ᆠ

   �  ᆠ犨  犨ᨨ�  � �犨矄�矄 ҈  ᨨ 犨 �  �ᨨᨨ  �  矄�泐ᨨ ��    ᨨ� ᨨ  ᆠ ᨨ ��  � ��矄 ᲼㝐�  ᔼᔼ桌 㡰 � 㡰 䰘 ᆠ㡰 � 㡰 䰘 ᔼ  Ӹᨨ盐 �矄 ᨨ盐 矄�  �鼀    矄�ᨨ

犨  矄�矄�矄҈�鼀鼀ᔼ   �鼀 矄ᨨ盐ᆠ ᨨ �� ᨨ 犨 � �黨 鼀�矄盐矄   �   ᆠ  �矄 ᨨ矄 ᨨ  矄ᆠ ├ ҈� 鼀 犨泐   矄�ᨨ 犨  矄盐ᆠᆠ矄矄���  � �矄ᨨ   矄ᆠ �矄 ᲼㝐� 䰘 ᔼᔼ桌 㡰 黨鼀鼀 㡰 黨鼀鼀 ᆠ㡰 �黨鼀鼀 㡰 黨鼀鼀 ᔼ  ᨨ盐矄� �鼀 犨   �  �鼀ᨨ  �ᆠ├ 矄矄t � � ᆠ��  Ҙ�矄� ᨨ 盐ᆠ �  ᨨ ᨨ ᨨ ᨨ  矄�矄 鼀 �鼀盐鼀 ᆠ ᨨ   � �

矄 � 矄 泐 ᨨ  � � 犨�    盐 ᨨ  t �矄  » �矄   犨 � ᨨ  �� 盐矄 㡰 ᲼㝐� ҈꾀�ᔼ桌 l l l l 㡰 㡰 ᆠ㡰 㡰 m - ҈㡰  m - ҈㡰 m - ҈㡰 m - ҈㡰

 ��盐矄 ᨨ犨矄Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 矄盐 ᔼ �矄 ᨨ矄    犨     �   矄  矄  ᨨ  �ᆠ├ 矄矄  ᆠ��  �矄盐�  ᨨ ᨨ ᨨ ᨨ  矄�矄 ᆠ 鼀 �鼀盐鼀�矄矄 �  泐 �矄 ᆠ ⼄盐ᨨ  � �犨�  矄ᔼ  犨 � ᨨ �� 盐矄 �矄 »犨� ᲼㝐� 黨꾀�҈黨ᔼ桌

nDl Dl nDl  Dl   㡰 㡰  ᆠ㡰 a (m 힘 ҈) a ( m 힘 ҈) a (m 힘 ҈) a (m 힘 ҈) ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀    �  ᆠ ᆠ� ᨨ� ᨨ  矄ᆠ 犨 犨ᨨ�  � �犨矄 ҈ �矄  ᨨ 犨 �  �ᨨᨨ  �  矄�泐 �矄  ᨨ� ᨨ  ᆠ ᨨ ��  � ��矄ᆠᨨ矄ᨨ ᲼㝐� ҈҈ ҈黨ᔼ桌 㡰 䰘 㡰 � ᆠ㡰 黨 㡰  ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 犨� 矄�矄�ᨨ

҈ ҈鼀鼀ᨨ ᨨ矄矄��  � � �  

㡰 

黨

Physics

泐 盐矄� � ��  ᨨ  犨 �  l҈ ␔     ��  ᨨ 犨 �  l �矄 盐矄  ��   � � �矄 矄    矄鼀 ��  矄鼀矄盐෌�  l҈ l � �矄� �  鼀ᨨ䰘 鼀㡰 �盐矄 ᲼㝐�  ҈   ҈黨 ᔼ桌 㡰 � 鼀� 鼀 㡰  鼀�� 鼀 㡰  鼀� 鼀 ᆠ㡰  鼀� 鼀 ҈ ᔴᨨ 矄� Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 矄矄 ᨨ犨 �

��盐␔ 矄 ᨨ盐  矄�矄�ᨨ  � 鼀矄ᨨ 犨 � l矄盐ᆠ    �矄鼀� �鼀ᨨᆠᆠ盐矄 �ᆠ泐 �  ᨨ ᨨ  矄� 和҈㡰䁸 ᲼㝐� ҈ ҈黨ᔼᔼ桌 和҈

和ᨨ盐ᆠ



矄

҈ 鼀� �鼀

和

㡰

l

 㡰

l



 ᆠ㡰

和ᆠ

l

 㡰

l

 � - 㡰 � - 㡰  � - 㡰 � - 㡰 ҈҈ ᔼ Ӹᨨ盐 �Ἐ矄 ᨨ盐矄� �鼀  矄�矄ᆠ  鼀鼀  ��  ᨨ  犨 �  l 㦨 � 鼀 �矄 � ᆠ�  ᨨ  矄�矄 ᨨ 盐鼀ᨨ ��  � �矄  ᨨ矄 �   �盐 � £q£ �矄 ᲼㝐� 黨 ҈黨ᔼᔼ桌 㡰  㡰  ᆠ㡰 ҈ 㡰 ҈ ҈ ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  矄�矄�ᨨ d �矄鼀鼀  矄ᆠ  �矄 ᆠD�矄҈鼀꾀鼀 ᨨ �� ᨨ 犨 �  鼀�矄� ᆠ�  ᨨ  矄�矄  �a矄矄 ᨨ犨 �  ��盐졠  矄ᆠ  ᨨ� O�矄 ⼄盐� �矄  ᨨ鼀 矄�矄  �矄 ᆠ졠�矄҈҈鼀鼀 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄⏌ᆠᨨᆠ䁸 ᲼꾀 ҈黨桌

㡰 ᨨa㦨 犨�ᆠᨨ 矄盐ᆠ��   ᆠ ᨨ� P 㡰 � �矄ᆠ� �  矄ᨨ a  ᆠ㡰 ᨨ a㦨   �   犨�  矄盐ᆠ� p �   ᆠᨨ� P  㡰 ᨨ a 㦨  �   犨�  矄盐ᆠ� p �   ᆠᨨ� O ҈ ᔼ Ӹᨨ盐 �Ἐ矄 ᨨ盐矄� �鼀 矄�矄矄 泐 �鼀鼀  矄ᆠ �矄ᆠ ҈�ᆠ鼀犨泐꾀鼀ᨨ �� ᆠᨨ 矄�矄� �ᨨ 犨ᨨ犨 � 矄� 鼀 � 鼀 �矄盐矄 ᨨᨨ� �   ᆠ � �矄ᨨ  矄ᆠ   矄 �矄 ᆠ ᨨ鼀 ᆠᨨ鼀鼀ᨨ ᆠ 鼀 �鼀盐鼀ᨨ  ᨨ� 犨  ��  � �矄 盐ᨨᨨ  犨 � 矄 ᆠᨨ� ᆠ� �矄 ᲼㝐� ҈䰘桌 㡰 黨䰘�鼀鼀 㡰 ҈�鼀鼀 ᆠ㡰 ҈�鼀鼀 㡰 䰘鼀鼀

WWW.JEEBOOKS.IN

P-269

Wave Optics

҈

҈�

҈

ᔼ   Ӹᨨ盐 �矄 ᨨ盐 矄�  �鼀  犨�  ��  ᨨ 犨 � l 矄�ᨨ ᨨ 矄�矄�矄   �矄 ᆠᨨ 矄ᆠ �矄矄盐ᆠ  >> >>lᔼ   � �犨�  �矄b  �矄 ᆠ ᨨ鼀ᨨ� ᨨ 鼀 �鼀盐鼀�  矄�泐ᨨ  ᨨ� 犨 �  矄�泐 矄ᨨ  ᨨ 鼀 �鼀盐鼀�  矄�泐 ᨨ  �  矄� �矄 ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 b b b b 㡰 㡰 ᆠ㡰 㡰     ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀   �矄 ᆠ犨

 犨ᨨ�  �ᆠ矄�矄�矄҈�鼀矄�   矄�犨�  

   盐鼀ᨨ �  矄�泐鼀 �鼀ᨨ矄 犨� �   ᆠ 鼀 �鼀盐鼀ᨨ  矄� �矄� � ᆠ�ᨨ  �矄 ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰  㡰  ᆠ㡰 ҈ 㡰 

犨ᨨᆠᨨ  ᨨ� 矄ᨨ盐ᆠ矄和҈ 和矄 泐 矄鼀 �矄 ᆠἘ Ἐ矄矄 ᨨ犨   � �矄ᨨ�  ᨨ   矄ᆠ 犨� ᲼㝐� ҈桌 和҈ 和

和ᆠ



㡰 ᨨ� 矄 ᆠ㡰 矄鼀�㜠ᆠ�ᆠ矄 ҈䰘

҈

҈黨



҈



㡰 矄�� � 矄 㡰 ᆠᨨ ᆠ �ᆠᆠ�ᆠ矄

� l  l�矄犨 �  ᨨ  ��  盐矄 㡰    ᆠ� �   m 㦨 ҈� �矄 � 矄 犨 ᨨ ᨨ  矄�矄  矄ᆠ � Ӹᨨ盐 �矄 ᨨ盐 矄� �鼀 꾀ᨨ� ᨨ  矄ᆠ ⼄盐� �矄  ᨨ鼀  矄�矄 �ᨨᨨ  �  矄��矄 ᨨ    � ᨨ 盐ᆠ�ᨨ ᨨ  �矄矄�矄 ᲼㝐� 졠 � 꾀��҈桌 ᆠ㡰 ҈ 㡰  㡰 ҈ 㡰 ҈ ᔼ    Ӹᨨ盐 �矄 ᨨ盐 矄�  �鼀  盐矄� �  鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ 犨 � l,    �  ᆠ � 鼀矄ᨨ  � �n㡰ᆠᨨ矄ᨨ � �ᨨ 泐ᨨ�  � �   ├�  矄�泐�矄 ᲼꾀 ҈桌 l l l l 㡰 n + ҈㡰  㡰 n +҈㡰  ᆠ㡰 n + ҈㡰  㡰 n +҈㡰 ҈    Ӹᨨ盐 �矄 ᨨ盐矄�  �鼀 �矄 ᆠ�  ᨨ盐 泐盐矄� � �   盐�� ᨨ ᆠᨨᨨ�鼀  � � 犨�  矄ᆠᨨ  GR B矄ᆠ�泐   ᲼҈桌 㡰 G>B>R 㡰 B>G>R ᆠ㡰 R>B>G 㡰 R>G>B ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 �  矄�泐ᨨ� �矄 ҈⏌ 㡰ᨨ  鼀 �鼀盐鼀�  矄�泐꾀 �盐ᨨ矄��ᨨ ᨨ  �矄ᨨ�  �矄 ᲼�和桌 㡰 矄� ҈ l⏌ 㡰 㡰 矄� ҈ l⏌ 㡰 ᆠ㡰 矄� ҈ l⏌ 㡰 㡰 矄� ҈ l⏌ 㡰 㝐ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ 犨 �  鼀 � 鼀 � ᆠ�  矄�鼀盐 ᨨ盐矄泐  ᨨ鼀泐ᨨ  ᨨ盐矄�矄 盐矄犨 ᨨ矄矄�矄矄�ᨨ �矄҈鼀鼀 矄ᆠ

�矄 ᆠ�矄҈鼀�矄 ᆠ犨 矄ᨨ ᨨ ├ 矄矄 犨� ᲼和桌 㡰 鼀鼀 㡰 �鼀鼀 ᆠ㡰 ҈鼀鼀 㡰 鼀鼀 ᔼ   �  ᨨ盐㜠矄� �鼀 犨  �矄矄㜠  ᆠ��  ҈�㡰ᨨ  �ᆠ├ 矄矄�矄� ᨨ 盐ᆠ �  

꾀 � �矄矄ᨨ  �ᆠ├ 矄矄�矄

 ᨨ ᨨ ᨨ  �  � �鼀矄 犨㜠 �  l 㡰  �  矄�泐    ᨨ矄��ᨨ  犨    ᆠ  鼀 �鼀盐鼀 ᨨᆠᆠ盐 �ᨨ盐矄泐鼀� 矄盐 ᆠ  �  鼀� �鼀盐鼀  �ᆠ├ 矄矄ᨨ  �矄矄㜠�矄 ᲼和桌 㡰  l 㡰  l ⏌ ᆠ㡰 l ⏌ 㡰 l  ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 ҈ � �矄ᨨ矄 ᨨ ᨨ鼀 � ᆠ� 矄�鼀 ᨨ  矄ᆠ 犨  ��  ᨨ 犨 �  鼀�矄盐矄 ᔼ  犨 � ᨨ �� �矄 ᆠ  � ᨨ 鼀 盐鼀ᨨ  � �矄ᨨ矄 �   矄鼀矄�鼀 ᨨ  矄ᆠ �矄�� 泐 ᲼҈和桌 㡰 ҈ 㡰 ҈ ᆠ㡰  㡰   ᔼ  ᨨ盐矄� �鼀 � 矄 ᨨ ├� �矄�矄ᨨ ⼄盐 犨�  矄ᨨ 矄��矄鼀 犨�ᆠ矄犨� 矄 ᨨ   �

 �   ᆠ

᲼和桌 㡰  �  矄��矄ᨨ ᨨ  鼀 �鼀  鼀� �鼀 � ᆠ矄 㡰  �  矄�泐ᨨ  鼀 �鼀� ᆠ矄矄  鼀� �鼀 矄 ᨨ�  矄�泐 ᆠ㡰  �  矄�泐ᨨ  鼀 �鼀 ᆠ矄矄  ᨨ   鼀� �鼀� ᆠ矄矄 㡰  �  矄�泐ᨨ  鼀 �鼀 ᆠ矄矄  鼀� �鼀 矄 ᨨ�  矄�泐 � ᔼ  �   ᆠ �鼀 矄�鼀�ᨨӸᨨ盐 �矄 ᨨ盐㜠 矄� �鼀  矄�矄S҈ S�盐鼀�  犨� ᆠᨨ  鼀�ᆠᨨ犨矄ᨨ盐ᆠ矄ᆠ ᨨ  ⼄盐 ᆠ泐҈ 

 矄ᨨ盐ᆠ矄  矄泐 ᆠ ᨨ �   ᨨ  ᨨ  矄 �  ᆠ 矄�矄矄 泐 �矄 ᆠ 㦨҈� 鼀 �  矄�泐I q㡰�矄鼀矄盐 矄 盐 ᆠ�ᨨ ᨨ q犨  q�矄  �  矄矄 ᨨ犨 ᔼ I�矄 鼀 �鼀盐鼀�  矄�泐 

I q㡰 ᨨ  £ q £ 黨 ° �矄�� 泐 ᲼҈黨黨�和桌 㡰

I q㡰 = I ⏌  fᨨr q = °

㡰

I q㡰 = I ⏌  fᨨr q = 黨°

ᆠ㡰

I q㡰 = I fᨨr q = °



I q㡰 �矄ᆠᨨ 矄  ᨨ

和҈ ⏌

⏌ 和

盐矄ᨨ q  ᔼ Ӹᨨ盐 �矄 ᨨ盐㜠矄� �鼀  矄�ᨨ 犨

 矄�矄�矄     �矄 ᆠ犨  矄�矄  矄ᆠ �矄 ᨨ盐   � �犨�  �矄᲼҈黨҈㜠㝐├矄桌 㡰 盐 ᆠ  �  㡰   ᆠ㡰 ᨨ盐 㡰 ⼄盐 盐 2

Integer Value Answer

䰘 꾀Ӹᨨ盐 �Ἐ矄 ᨨ盐矄��   ᆠ �鼀 犨� 矄�矄  S҈ S�矄�鼀鼀矄 � 犨  ᆠ��  㦨 㡰矄  矄 ᨨ犨 �   ��盐  ᨨ矄��ᨨ 矄ᨨ 鼀 �鼀盐鼀ᨨ

  矄盐 ᆠ ᨨ 犨  S ��  泐 x 㦨 pml  d 꾀� x d   犨  l �矄   犨 � ᨨ �� � � d  ᆠ��  㦨҈㡰d�矄 S ␔   矄�ᨨ  犨

  矄�矄   m �矄 

� � 盐ᨨ p�矄 ᲼꾀 ҈�桌 ҈



WWW.JEEBOOKS.IN

EBD_8341 P-270

Physics

Numeric Answer

3 

黨

꾀泐ᨨ盐 �矄 ᨨ盐㜠矄�  �鼀  �矄  ᨨ鼀  盐矄� � 鼀ᨨ ᨨᆠᨨ鼀�ᆠ�� ᨨ 犨 � l �

 矄�泐ᨨ �� ᨨ� ᨨ  矄ᆠ 犨    �  ᆠ�矄 l�矄⧤盐 �矄 �  矄�泐ᨨ �� ᨨ� 犨   l

⧤   �  ᆠ�矄 �矄�� 泐 犨  �矄 � 㜠  ҈ � 盐ᨨ n�矄힘힘힘힘힘힘 ᲼㝐� 和 ᔼᔼ㡰桌 ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 ҈� � �矄ᨨ矄 ᨨ 矄鼀ᨨ�ᨨ ᨨ  矄ᆠ 犨  �� ᨨ 犨 � � 鼀�矄盐矄    � �矄ᨨ矄 ᨨ  矄鼀 矄ᆠ�ᨨ  ᨨ    矄ᆠ  犨    ᨨ  ��  矄ᨨ盐ᆠ ᨨ 犨 �  l�矄 盐矄     盐 ᨨ  l �矄 �  鼀㡰 힘힘힘힘힘힘 ᲼㝐� 黨 ᔼᔼ桌 Fill in the Blanks

4 

ᔼ Ӹᨨ盐 �矄 ᨨ盐㜠矄�  �鼀    犨ᨨ矄�矄ᆠ 矄 ᆠᨨ  矄ᨨ盐ᆠ矄ᨨ ⼄盐鼀�盐 �A ᨨ 犨 � � l ᔼ  ᨨ  �鼀 犨�  矄鼀矄㜠盐 犨ᨨ 矄�矄矄ᨨ盐ᆠ矄ᨨ ⼄盐鼀�盐 �A 犨 � � l 盐� ᆠᨨ   �ᨨᨨ  �  矄�泐ᨨ ��   鼀� ᨨ� ᨨ  矄ᆠ �   �矄ᆠ矄ᨨ �   矄ᆠᨨ ᆠ矄�矄 ᲼҈黨㜠㝐├矄桌 True / False

5 ҈



ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  ᨨ鼀 犨� 矄ᨨ盐ᆠ ᨨ 犨 ��� ᨨ 泐ᆠ├ 犨 � � �矄ᨨ矄  ᲼҈黨䰘㜠㝐├矄桌

 犨ᨨ矄�矄 �   Ӹᨨ盐 �矄 ᨨ盐 矄�  �鼀   �盐鼀�  泐犨ᨨ �  矄ᨨ �盐鼀鼀矄鼀�� ��� ᨨ   矄鼀 犨 �  ᨨ �   ᆠ   犨�  ᨨ矄 ᨨ   矄ᆠ  ᲼҈黨㜠㝐├矄桌

MCQs with One or More than One Correct Answer

6

졠 和҈

和





和ᆠ

 ␔ �ᆠᨨ 盐ᆠ� � Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  矄盐  ᆠ  犨ᨨ矄�矄犨� �ᨨ⼄盐�

  㜠泐 ᆠᨨ � � �犨ᨨ矄鼀 ᨨ矄 ᆠ矄犨ᨨ ᆠᨨ  ᨨ� 矄ᨨ盐ᆠ矄 和҈和㡰鼀�� ��� ᨨ 犨 �  鼀 矄盐  鼀�矄├ 泐ᆠ  矄ᆠ  ᨨ  㜠   ᨨ >㡰 �矄 ᆠ㦨鼀 ᨨ鼀  鼀� 㜠ᨨ� ᨨ 和҈和矄矄 ᨨ犨 矄ᆠ 鼀�ᆠ泐�   ��盐

 �矄 ᆠ犨   矄ᨨ盐ᆠ矄  㦨 鼀鼀  ᨨ��� 졠�矄 � 矄ᆠ�ᨨ ᨨ  矄ᆠ   �  ᨨ� � �和҈和␔ �ᆠ ᨨ   ᨨᨨ犨� ��矄 㡰盐ᨨ   �  矄�泐 ᨨ  矄ᆠ 䁸 ᲼꾀 ҈桌

㡰 和�� ��   ├ 矄ᨨ  㜠 �矄 㡰 ��ᨨ 泐ᆠᨨ矄ᨨ ᨨ� 졠犨� ├ ᆠ㡰 泐ᨨ�ᆠ ��     ├  矄 犨�  ᨨᆠ� 矄泐鼀鼀�ᆠ泐ᆠ ᨨ盐졠�   㜠 �ᆠ�ᨨ

㡰 和鼀�ᆠ�ᆠ盐��   ├ 矄ᆠ  ᨨ�   꾀�� 矄ᨨ盐ᆠ犨 �ᆠ 鼀�矄犨ᨨ犨 � l҈㦨 鼀  l㦨 鼀�矄盐矄 � Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  ᔼ ᆠᨨ   � �犨�  矄 ᨨl҈ lb҈ b   盐鼀ᨨ  � �矄 ᨨ 鼀犨� �  �矄 ᆠyᨨ ᨨ  矄� ᨨ  ᆠ 鼀 �鼀盐鼀m҈ m矄ᆠ�泐 ᲼꾀 ҈桌  

㡰 b>b҈ 㡰 m҈>m ᆠ㡰 ᨨ鼀 ᆠ 鼀 �鼀盐鼀 鼀 �鼀盐鼀ᨨ lᨨ矄 犨� � 鼀� �鼀盐鼀ᨨ l҈ 㡰  �盐 矄�ᨨ  ᨨ  � �矄 ᨨ l҈�矄 �   l � ᔼ Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  矄�ᨨ 㜠 犨  犨ᨨ矄�矄�矄   犨 � ᨨ  �� �矄 l �  矄�泐ᨨ ��  � �ᨨ 矄�҈�矄 ᨨ盐�鼀矄  �  矄�泐ᨨ ��  � � ᨨ  矄�  ᔴ ᨨᨨ矄   ᆠᨨᆠ ᆠ ᨨ�ᆠ 矄㡰 ᲼桌 㡰 ᔼ  㦨l 矄ᆠ 犨�ᆠᨨ � ᨨ 泐ᨨ 鼀 �鼀盐鼀 㡰 ᔼ l l矄ᨨ 鼀ᨨ鼀 �鼀盐鼀 矄� 矄  ᆠ 鼀 �鼀盐鼀㡰犨�ᨨ矄 ᨨ  矄ᆠ

ᆠ㡰 ᔼ  �  矄�泐ᨨ ��  � �ᨨ 矄�҈�矄 盐ᆠ 矄ᨨ  �ᆠᨨ鼀矄⼄盐ᨨ ᨨ 矄� �  矄��矄 ᨨ  ᨨ矄  ├ ��  � �矄犨�� ᆠ矄 㡰 ᔼ  �  矄�泐ᨨ ��  � �ᨨ 矄��矄� ᆠ矄 矄ᨨ  �ᆠᨨ鼀矄⼄盐ᨨ ᨨ 矄�҈ �  矄��矄 ᨨ  ᨨ矄  ├ ��  � �矄犨�� ᆠ矄  ␔ ��� �矄盐矄 ᨨ�盐鼀�  犨ᨨ矄�矄� Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  矄�ᨨ 犨  矄�矄�矄 b  矄ᆠ �矄 �矄 ᆠd >b㡰 ᨨ鼀 矄�矄꾀 ᨨ� ᨨ  矄ᆠ  �ᆠ泐�  ᨨ ᨨ ᨨ ᨨ  矄�矄 ᆠ� 犨 � 矄鼀�矄矄� �和ᨨ鼀ᨨ  矄鼀�矄矄� � ᲼҈黨㜠㝐├矄桌 犨 � 矄 b b  b b  ᆠ㡰 l = 㡰 l = 㡰 l = d d d d 䰘 ᔼ  Ӹᨨ盐 �矄 ᨨ盐矄� �鼀  �   ᆠ   �矄 ᨨ盐 ᨨ   �  矄�泐�ᨨ犨    ��   ├ � �矄矄黨 �矄�鼀�矄  ᲼҈黨㜠㝐├矄桌 㡰  �  矄��矄 矄ᆠ  盐ᨨ 犨ᨨ矄�矄� 盐 �矄 盐 �矄矄ᆠ�泐 㡰  �  矄��矄 矄ᆠ  盐ᨨ 犨ᨨ矄�矄 盐 �矄 ҈盐 �矄矄ᆠ�泐 ᆠ㡰  鼀�盐 �ᨨ�矄 㡰  鼀�盐 �ᨨ�矄

㡰 l =

7



Match the Following

 ᔴᨨ盐鼀 㜠ᔼ 矄 ᨨ犨矄 ᨨ盐 矄�盐�ᨨ 矄 ᨨ  矄   Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 犨�  矄ᆠ ᆠ  犨泐 ᨨ鼀 矄�矄和҈ 和ᔼ ᆠ ᨨ  矄ᆠ矄矄和҈㦨和 和҈҈㜠和҈㦨 l/4  和҈ 和㦨 l⏌ 犨  l �矄   犨 � ᨨ  �� 盐矄 ᔼ  ᆠ矄矄ᔴ 



WWW.JEEBOOKS.IN

P-271

Wave Optics

 矄 矄 ᨨ  ᆠ��  m   �ᆠ├ 矄矄t�矄 矄 ᨨ 矄�和  �ᆠ├ 矄矄矄ᨨ  矄 矄 �   �  �  ᆠ矄矄  矄 �  ᆠ犨  ��  犨矄ᆠ � �ᨨ� ᨨ  矄ᆠ  ᨨ鼀 犨ᨨ矄�矄 �矄  ᨨ 泐d 㡰  �  矄�泐泐I 㡰㝐ᆠ ᆠ 矄�盐�ᨨ  ��  �  ᔴᨨ盐鼀 㜠ᔼ 犨�    矄鼀  矄㡰 �

᲼黨桌 ᔴᨨ盐鼀 㜠ᔼᔼ�  ᨨ 矄�盐�ᨨ  ᔴᨨ盐鼀 㜠ᔼ ᔴᨨ盐鼀 㜠ᔼᔼ  ҈ 

和

꾀㡰 和҈

㡰 d 㡰㦨 㡰 m ҈㡰t㦨l⏌



 ҈ 

和



和҈

⼄㡰 d ҈㡰㦨

ᔴ㡰 m ҈㡰t㦨l⏌  㡰 I ҈㡰㦨 和

㡰 m ҈㡰t㦨3l⏌ 和

 ҈ 

҈

矄㡰 I 㡰>I ҈㡰 I 㡰>I ҈㡰

10 Subjective Problems





和ᆠ

和҈

黨

㦨҈鼀鼀

㦨҈鼀

 ҈ 

和

㡰

㡰 �  ᨨᆠ�ᨨ ᨨ  ᆠ 鼀 �鼀盐鼀 ��  � � 犨�  ᨨ  �  ᆠ㡰ᨨ  泐 �矄 㡰 �    ��  �  矄�泐  ᨨ�  O � ᨨ  鼀 �鼀盐鼀 � ��  矄�泐 ᆠ㡰 ᨨ犨�  鼀�� �矄ᆠ 泐犨 ��� ᨨ  � ᨨ䰘 鼀 �  犨 � 矄ᨨ  ��   ᨨ鼀鼀 �鼀 ᆠ泐ᨨ� O ᲼꾀犨 � 矄�  �矄ᨨ鼀 ᨨ ��

鼀 �盐鼀ᨨ  ᆠ��  ⏌ᔼ� ᨨ �矄矄�ᨨ 桌 ҈ 꾀ᆠᨨ  鼀ᨨ 鼀�ᆠᨨ犨矄ᨨ 犨 � l 㦨 � 鼀鼀 矄 ᨨ   Ӹᨨ盐 �矄 ᨨ盐 矄� 盐矄  矄�ᨨ 犨  矄�矄�矄҈鼀鼀 �  矄�泐ᨨ 鼀�ᆠᨨ犨矄�矄鼀矄盐 ᨨ 矄ᆠ ᆠ ᨨ   ᨨ  矄�矄 �矄 ᆠᨨ ҈鼀 ᨨ鼀�矄矄 ᨨ犨 �

��

ᔼ YDSE�� ᆠᨨ � � �犨ᨨ犨 � 矄� 鼀 䰘 鼀盐矄  �  鼀� �鼀盐鼀 �矄 ᆠ犨 鼀 �鼀 ᨨ 犨ᨨ犨 � 矄ᆠᨨ� ᆠ� ෌� D/d㦨҈犨 D�矄   �矄 ᆠ犨  矄�矄  矄ᆠ  d�矄  �矄 ᆠ犨  矄�矄 ᲼㜠㝐├矄桌

Ӹᨨ盐 �矄 ᨨ盐矄� �鼀 �矄 ᨨ � 鼀 �盐鼀ᨨ  ᆠ��  ⏌꾀�� ᨨ  鼀犨 � �矄 � � ᨨ  矄�矄 � ��鼀鼀矄�ᨨ  ᨨ犨矄�S�矄 ᆠᨨ 泐 � �矄矄矄 ᨨ  �ᆠ├ 矄矄҈m鼀  ᆠ��  ҈� �   ᆠ �矄ᨨ矄 ᨨ 矄ᆠ ᆠ ҈�鼀 ᨨ鼀 矄�矄矄矄 ᨨ犨 �  ��盐 ᲼҈黨黨黨㜠҈㝐├矄桌 Ӹ

和҈ 졠

和ã 和

㡰 ᔼ  � ᆠ�  鼀 矄 ᨨ鼀泐ᨨ   ᨨ盐矄�  盐矄 �    泐㜠ᆠᨨᨨ � 矄 ᨨ     �   ᆠ鼀� �鼀ᨨ  矄ᆠ  㡰 ᔼ  � ᆠ�  鼀鼀├矄  �ᨨ  犨�  x  �矄 矄�   ᨨ ᨨ犨矄 ᨨ犨 �  ��盐㡰 �   y㜠ᆠᨨᨨ � ᨨ   �矄鼀� �鼀ᨨ � 矄� ᨨ   ᲼҈黨黨㜠㝐├矄桌 ᆠ 鼀 �鼀盐鼀  ᔼ Ӹᨨ盐 �矄 �鼀  盐矄��矄ᆠᨨ 泐 �

�矄矄ᨨ  ᆠ��  ҈犨 � ᨨ犨矄��矄 ᆠᨨ 泐 ᨨ �矄矄 � � 矄鼀 �ᆠ├ 矄矄 矄  �矄ᨨ 盐 � � ᆠ��  ҈䰘ᔼ   ᆠ  �矄ᨨ矄 盐矄� ��� ᨨ 犨 � �处ᔼ�矄 ᨨ盐   ᨨ� Pᨨ   矄ᆠ  犨   ᆠ  鼀 �鼀盐鼀 㦨㡰 矄 ᨨ �矄矄矄犨� 矄

ᨨ犨 矄⏌ ᨨ��� �  矄�泐ᔼ�矄 盐 ᨨ矄  犨 盐矄 ᨨ  �  鼀 �鼀盐鼀��矄ᨨ犨  ᨨ� P犨 � 矄�  鼀� �鼀盐鼀�矄ᨨPᔴᆠ盐   �ᆠ├ 矄矄ᨨ  �矄矄 꾀矄ᨨ�ᨨ ᨨ �� 泐 �矄矄鼀泐 �ᆠ 㡰 ᲼҈黨黨䰘㜠�㝐├矄桌  꾀 ᨨ盐㜠矄�盐矄�矄�鼀鼀矄 � �⼄盐� ᨨ  ᆠ� �  ҈ᔼ 矄矄�矄�ᨨ ᨨ ҈鼀鼀  �矄 ᆠ 犨   ᨨ 矄�矄 矄ᆠ �矄҈鼀 矄�矄  �盐鼀�   泐   鼀 ᨨ  ��  犨 ᨨ矄 犨 � � ��矄处 ᲼҈黨黨㜠㝐├矄桌 �㡰 ᔴᆠ盐  � �㜠犨�   ��㡰 졠 ᨨ  矄�矄ᨨ  盐矄�矄ᆠᨨ 泐 �

�矄矄矄 ᨨ  ᆠ��  ҈� �  矄鼀矄  �ᆠ├ 矄矄ᨨ  矄 ᨨ� �  ᆠ 鼀� �鼀盐鼀 ᨨ   �矄  ᔼ   鼀ᨨ � �  Ӹᨨ盐 �矄 ᨨ盐 矄�  �鼀   鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ 盐 � ᨨ鼀    鼀 ᨨ ��  ᨨ 犨 � 处 �  矄�泐 ҈⏌ p 㡰␔鼀�矄� ᆠ�  

ᨨ鼀泐ᨨ 犨ᨨᆠ�ᆠ盐盐矄꾀 ᨨ  ��҈鼀  鼀矄ᆠ�泐꾀 ᆠ泐 矄  �鼀ᨨ  �ᆠ├ 矄矄  处    ᆠ� �   ҈� ᨨ   犨 � ᨨ 处�矄ᆠ �  ᨨ ᨨ 盐A矄

WWW.JEEBOOKS.IN

EBD_8341 P-272

Physics

fig. Calculate the power (in watts) received at the focal spot F of the lens. The lens is symmetrically placed with respect to the apertures. Assume that 10奠 of the power received by each aperture goes in the original direction and is brought to the focal spot. [1989 - 8 Mark]

A

F

B

45. A beam of light consisting of two wavelengths, 6500Å and 5200Å, is used obtain interference fringes in a Young’s double slit experiment : [1985 - 6 Marks] (i) Find the distance of the third bright fringe on the screen from the central maximum for wavelength 6500Å. (ii) What is the least distance from the central maximum where the bright fringes due to both the wavelengths coincide? The distance between the slits is 2 mm and the distance between the plane of the slits and the screen is 120 cm.

Topic-3 : Diffraction, Polarisation of Light and Resolving Power 1 1.

2.

3.

4.

5.

MCQs with One Correct Answer

A beam of plane polarised light of large cross-sectional area and uniform intensity of 3.3 Wm–2 falls normally on a polariser (cross sectional area 3 × 10–4 m2) which rotates about its axis with an angular speed of 31.4 rad/s. The energy of light passing through the polariser per revolution, is close to : [Main Sep. 04, 2020 (I)] –5 (a) 1.0 × 10 J (b) 1.0 × 10–4 J –4 (c) 1.5 × 10 J (d) 5.0 × 10–4 J The aperture diameter of telescope is 5m. The separation between the moon and the earth is 4 × 105 km. With light of wavelength of 5500 Å, the minimum separation between objects on the surface of moon, so that they are just resolved, is close to: [Main 9 Jan. 2020 I] (a) 60 m (b) 20 m (c) 200 m (d) 600 m A polarizer - analyser set is adjusted such that the intensity of light coming out of the analyser is just 10奠 of the original intensity. Assuming that the polarizer analyser set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero, is: [Main 7 Jan. 2020 I] (a) 71.6° (b) 18.4° (c) 90° (d) 45° The value of numerical aperature of the objective lens of a microscope is 1.25. If light of wavelength 5000 Å is used, the minimum separation between two points, to be seen as distinct, will be : [Main 12 April 2019 I] (a) 0.24 µm (b) 0.38 µm (c) 0.12 µm (d) 0.48 µm A system of three polarizers P1, P2, P3 is set up such that the pass axis of P3 is crossed with respect to that of P1. The pass axis of P2 is inclined at 60o to the pass axis of P3. When a beam of unpolarized light of intensity Io is incident on P1, the intensity of light transmitted by the three polarizers is I. The ratio (Io/I) equals (nearly) : [Main 12 April 2019 II]

6.

7.

8.

9.

(a) 5.33 (b) 16.00 (c) 10.67 (d) 1.80 Diameter of the objective lens of a telescope is 250 cm. For light of wavelength 600 nm. Coming from a distant object, the limit of resolution of the telescope is close to: [Main 9 April 2019 II] (a) 1.5 ´ 10 -7 rad(b) 2.0 ´ 10-7 rad (c) 3.0 ´ 10 -7 rad (d) 4.5 ´ 10-7 rad Calculate the limit of resolution of a telescope objective having a diameter of 200 cm, if it has to detect light of wavelength 500 nm coming from a star. [Main 8 April 2019 II] (a) 305 × 10–9 radian (b) 610 × 10–9 radian (c) 152.5 × 10–9 radian (d) 457.5 × 10–9 radian In a double-slit experiment, green light (5303Å) falls on a double slit having a separation of 19.44 µm and a width of 4.05 µm. The number of bright fringes between the first and the second diffraction minima is : [Main 11 Jan 2019 II] (a) 10 (b) 05 (c) 04 (d) 09 Consider a tank made of glass (refractive index 1.5) with a thick bottom. It is filled with a liquid of refractive index m. A student finds that, irrespective of what the incident angle i (see figure) is for a beam of light entering the liquid, the light reflected from the liquid glass interface is never completely polarized. For this to happen, the minimum value of m is: [Main 9 Jan. 2019 I]

(a)

5 3

(b)

3 5

(c)

5 3

(d)

4 3

WWW.JEEBOOKS.IN

P-273

Wave Optics

҈

҈҈

҈

҈

 �盐犨�  ᨨ  ᆠ 鼀 �鼀盐鼀� 矄� �矄� � ᆠ�ᨨ  �矄  犨�  ᨨ  矄��矄҈m鼀  矄� �矄 �盐鼀�   泐鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ   犨矄 ᔼ  ᨨ 矄�ᨨ 矄鼀犨�  �矄鼀  �Ӹᨨ盐 �Ἐ矄 � �矄 ᆠ ᨨ矄 ᨨ 矄ᆠ ᆠ  �矄 ᆠ�ᆠ鼀 ᨨ鼀 矄�矄ᔼ  ᨨ矄  � �犨�  �矄҈ᆠ鼀犨 �矄 矄�矄�ᨨ  �矄 ᆠ䁸 � �矄 ᆠ犨  ᆠ 矄ᨨ ᆠ 矄�㡰᲼㝐� ҈桌 㡰 �m鼀 㡰 �m鼀 ᆠ㡰 䰘�m鼀 㡰 ҈m鼀  ᨨ�  �� ᨨ �  矄�泐ᔼ矄矄矄 ᨨ盐�  �  ᨨ� 꾀꾀 ᨨ �  �ᆠᨨ� �矄ᆠ  � ᔼ 꾀 �  矄�泐ᨨ �� 泐ᨨ �矄 ᨨ盐 ᨨ ᨨ犨   ᨨ �  �ᆠᨨ� ᔴ�矄ᆠ 犨 꾀 

�  矄�泐泐ᨨ �矄 ᨨ犨 ᨨ盐 ᨨ ᔼ   �  犨 ᨨ� 꾀 ᔴ�矄 ᲼㝐� ҈桌 㡰  㡰  ᆠ㡰 � 㡰  �� ᨨ 犨 � �� 鼀 矄 ᨨ鼀泐ᨨ 矄�ᨨ 犨�  맔҈�ᆠ鼀  �盐ᨨ矄��ᨨ ᨨ  矄ᆠᨨ 鼀� �鼀 ᨨ鼀 ᆠ 鼀 �鼀盐鼀犨� �  � 矄㡰 ᲼㝐� 졠 � 꾀�҈�҈桌 p p p p 㡰 㡰 ᆠ㡰 㡰  ҈    ᨨ�  �� ᨨ �  矄�泐ᔼ�矄� ᆠ�  ᨨ 矄泐矄鼀ᨨ 犨ᨨᨨ� 矄꾀 ᨨᨨ犨 泐 �  矄�泐ᨨ 鼀�  �� �矄ᔼ⏌ᔼ  � ᨨ� ᔴ�矄ᆠ 犨 꾀   �  矄�泐ᨨ 鼀� �� �矄 盐ᆠ ᨨᔼ⏌  � 犨  ᨨ� 矄꾀 ᔴ�矄q 

᲼㝐� 졠 � 꾀�҈҈桌 ҈⏌ 

æö 㡰 ᆠᨨ矄 q = ç ÷ èø

҈⏌ 

҈

҈�

҈

҈䰘

҈

҈黨

҈⏌ 

æ҈ö 㡰 ᆠᨨ矄 q = ç ÷ èø

҈⏌ 

æ҈ö æö ᆠ㡰 ᆠᨨ矄 q = ç ÷ 㡰 ᆠᨨ矄 q = ç ÷ èø èø 꾀 ᨨ矄�矄鼀ᨨ� �犨�    矄 ᨨ �� ᨨ犨 矄 矄�ᨨ 泐鼀�ᆠᨨ犨矄ᨨ盐ᆠ鼀�� �犨矄 ⼄盐 ᆠ泐 ҈෌ ␔ �矄  ⼄盐 ᆠ泐ᨨ  鼀�ᆠᨨ犨鼀矄盐 泐 ᨨ矄䁸 矄 ᨨ �� 㦨맔҈鼀矄҈㡰᲼㝐� ҈䰘桌 㡰 ҈䰘෌ 㡰 ҈�෌ ᆠ㡰 ҈҈෌ 㡰 ҈҈෌ 꾀 矄� � 矄� ᨨ 犨�   b �矄 �盐鼀�   泐 ᆠᨨ   鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ 犨 � lᔼ  矄ᆠᨨ  ᨨ盐 鼀� �鼀�   � ᆠ�ᨨ   �矄 ᆠ҈鼀 ᨨ鼀 矄�ᆠ鼀 ᆠ鼀矄ᆠ�泐 ᨨ鼀  ᆠ 鼀 �鼀盐鼀犨 �矄 犨�  ᨨ  ᆠ 鼀 �鼀盐鼀䁸 � �矄 ᆠ犨  �矄鼀� �鼀盐鼀ᨨ � 矄� ᨨ   ᆠ 鼀 �鼀盐鼀㡰 ᲼㝐� 졠 � 꾀�҈䰘桌 㡰 ҈�ᆠ鼀 㡰 ᆠ鼀 ᆠ㡰 �ᆠ鼀 㡰 ᆠ鼀

ᨨ ᨨ �  ᨨᆠ鼀ᨨ  �  矄 ᨨᨨ  �盐矄ᔼ�矄矄矄盐鼀  犨    ᨨ�矄�盐鼀�  泐 鼀ᨨ �� ᨨ 犨 � l 矄 ᨨ   矄ᨨ ᨨ�  ᨨ  ᨨᨨ矄�犨ᨨ  ᆠ鼀㡰�矄  矄盐鼀 ᨨ  �矄 �ᨨ鼀�ᆠ 矄      矄  盐 ᨨ � ᆠ�ᨨ  矄ᨨ犨ᨨ盐    �矄鼀� �鼀盐鼀矄�  (say b鼀� 㡰犨   ᲼㝐� ҈桌 㡰  = l   鼀� = l l   鼀� = l 㡰  = 

æ l ö l  鼀� = ç ÷ ç  ÷  è ø æ l  ö ÷ 㡰  = l    鼀� = çç ÷ è  ø

犨ᨨ矄矄҈�� 泐矄犨泐 ᨨ鼀   泐 矄  ᨨ盐� 矄ᆠᨨᨨ ᨨᆠ� �鼀ᆠ鼀  犨 � ᨨ �� �矄 鼀 ᨨ矄 矄矄盐矄矄ᨨ 泐  矄ᆠᨨ   鼀� �鼀盐鼀 �矄 ᆠ 犨   鼀 矄 ᨨ盐  ҈�� 泐㦨黨맔҈҈�鼀㡰ᨨ  ᨨ ᨨ  ᲼㝐� 졠 � 꾀�҈҈桌  ҈ 㡰 ҈ ├鼀 㡰 ҈ ├鼀 ᆠ㡰 ҈҈҈├鼀 㡰 ҈├鼀 꾀矄矄盐鼀� � 盐鼀 盐�ᨨ  �盐矄ᨨ �ᆠ鼀  ᆠᨨ鼀 ᨨ �犨� � �矄 ᆠ ᨨ � ᆠ鼀   鼀� �鼀盐鼀 矄�ᨨ 犨 犨ᨨᨨᆠ矄  盐鼀 泐ᆠ 矄ᨨ � 鼀犨 � �矄 ᲼㝐� ҈�桌 㡰 ҈Ҙ鼀 㡰 Ҙ鼀 ᆠ㡰 ҈Ҙ鼀 㡰 Ҙ鼀  ᨨ�  �� ᨨ �  矄�泐ᔼ�矄� ᆠ�  ᨨ 矄盐 ᆠᨨ ᨨᆠ├ᨨ �矄矄犨矄矄 �ᔼ  ᆠ矄犨 �ᆠ ᨨ  ᨨ   ᨨᨨ犨� � 矄鼀 矄 �矄 盐 䁸 ᲼㝐� 졠 � 꾀�҈҈҈�桌 㡰  ᆠ �� �矄ᆠᨨ鼀泐ᨨ�  犨� �  矄�泐 I0 矄矄    2 㡰  矄鼀� �� �矄ᆠᨨ鼀泐ᨨ�  犨� �  矄�泐 I0 矄矄    2 ᆠ㡰  矄鼀� �� �矄�泐ᨨ�  犨� �  矄�泐 I0 2 㡰  ᆠ  ��  �矄 �泐 ᨨ�   犨�  �  矄�泐 I0 2

犨ᨨ鼀矄꾀 ᨨ  ᨨ�  �� 犨� 鼀盐盐泐  �ᆠ盐 矄ᨨ ᨨ� �ᨨ 矄  ᨨ盐�  ᨨᨨ�  ᨨ鼀 ᨨ矄��ᨨ 犨   鼀꾀 矄鼀 �鼀盐鼀 �  矄�泐  鼀 矄 ᨨ�  矄�泐㡰ᨨ�ᨨ ᨨ ᨨᨨ�  ᨨ盐�  ° 鼀├矄 犨ᨨ鼀矄⼄盐泐 �� ᔼ  � ���  矄��矄ᨨ  犨ᨨ鼀矄ᔼ꾀 ᔼ ᔼ矄ᆠ�泐   꾀 ⼄盐矄 ᲼㝐� ҈桌 ᔼ ҈  㡰  㡰 ᆠ㡰 ҈ 㡰   꾀泐ᨨ �� �矄� ᆠ�   ᨨ鼀  矄ᨨ鼀 �盐鼀

 ᆠ��ᆠ  � ᨨ ᨨ �     ᆠ�ᨨ  �矄 q�ᔴ  犨矄矄 �ᨨ � ᆠ�  ᆠ�矄q�矄盐ᆠ  矄� q�ᔴ⏌ 矄� q�㦨h㦨҈ � ᆠ��  ᨨ  犨ᨨ 鼀 ��矄 ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰  㡰  ᆠ㡰  㡰 黨 ᔼ    �鼀 ᨨ 矄� �矄� � ᆠ�ᨨ   �矄 鼀� �鼀盐鼀 ᨨ �� ᆠᨨ� ᆠ� 矄犨�  �矄鼀 �鼀盐鼀ᨨ 矄ᨨ鼀 ᨨ 犨 � ᔼ 犨 � ᨨ  �� �矄处   犨 � ᨨ  �矄鼀 �鼀盐鼀犨� ᲼㝐� 졠 � 꾀�҈҈桌 㡰 处 㡰 处 ᆠ㡰 ��处 㡰 处 ᆠ㡰  =



҈



WWW.JEEBOOKS.IN

EBD_8341 P-274

23.

24.

Physics

Abeam of unpolarised light of intensity I0 is passed through a polaroidAand then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of the emergent light is [Main 2013] (a) I0 (b) I0/2 (c) I0/4 (d) I0/8 A person lives in a high-rise building on the bank of a river 50 m wide. Across the river is a well lit tower of height 40 m. When the person, who is at a height of 10 m, looks through a polarizer at an appropriate angle at light of the tower reflecting from the river surface, he notes that intensity of light coming from distance X from his building is the least and this corresponds to the light coming from light bulbs at height 'Y' on the tower. The values of X and Y are 4 ) 3 [Main Online April 9, 2013]

respectively close to (refractive index of water ;

L

40 m

10 m

Y

X

50 m

25.

(a) that the central maximum is narrower (b) more number of fringes (c) less number of fringes (d) no diffraction pattern 26. Consider Fraunhoffer diffraction pattern obtained with a single slit illuminated at normal incidence. At the angular position of the first diffraction minimum the phase difference (in radians) between the wavelets from the opposite edges of the slit is [1995S] (b) p / 2 (c) 2 p (a) p / 4 (d) p 27. A beam of light of wave length 600 nm from a distance source falls on a single slit 1 mm wide and a resulting diffraction pattern is observed on a screen 2m away. The distance between the first dark fringes on either side of [1994 - 1 Mark] central bright fringe is (a) 1.2 cm (b) 1.2 mm (c) 2.4 cm (d) 2.4 mm 28. A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of the slit is [1998 - 2 Marks] (a) 0 (b) p/2 (c) p (d) 2p

(a) 25 m, 10 m (b) 13 m, 27 m (c) 22 m, 13 m (d) 17 m, 20 m Yellow light is used in a single slit diffraction experiment with slit width of 0.6 mm. If yellow light is replaced by X– rays, then the observed pattern will reveal, [1999S - 2 Marks]

3

Numeric Answer

29. Orange light of wavelength 6000 × 10–10 m illuminates a single slit of width 0.6 × 10–4 m. The maximum possible number of diffraction minima produced on both sides of the central maximum is _____________. [Main Sep. 04, 2020 (II)]

Topic-4 : Miscellaneous (Mixed Concepts) Problems 4 1.

A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at a distance of 9 meters and 25 meters respectively from the source. The ratio of amplitudes of the waves at P and Q is ............ [1989 - 2 Marks] 7

2.

8

Fill in the Blanks

Match the Following

A simple telescope used to view distant objects has eyepiece and objective lens of focal lengths fe and fo, respectively. Then [2006 - 6M] Column I Column II (A) Intensity of light received (p) Radius of aperture by lens (B) Angular magnification (q) Dispersion of lens (C) Length of telescope (r) Focal length of objective lens and eyepiece lens (D) Sharpness of image (s) Spherical aberration

Comprehension/Passage Based Questions

Passage The figure shows a surface XY separating two transparent media, medium-1 and medium-2. The line ab and cd represent waveforms of a light wave travelling in medium-1 and incident on XY. The lines ef and gh represent wavefronts of the light wave in medium-2 after refraction. [2007] b d

X

a c

medium-1 Y f h medium-2

e g

3.

Light travels as a (a) parallel beam in each medium (b) convergent beam in each medium (c) divergent beam in each medium (d) divergent beam in one medium and convergent beam in the other medium.

WWW.JEEBOOKS.IN

P-275

Wave Optics

 矄矄ᨨ  �� 犨cde  fᆠf f f 矄ᆠ�泐ᔼ�矄��  fᆠ¹f  㡰 fᆠᆠ

ᨨ⼄盐ᨨf 㡰 f ᆠ ⼄盐ᨨf ᆠ㡰 f f 㡰�矄⼄盐ᨨ fᆠf㡰 㡰 f fᆠ㡰�矄 ᨨ⼄盐ᨨ f f㡰 和 ᨨ �� �矄 㡰  矄鼀� 鼀 �盐鼀㜠҈ 鼀 �盐鼀㜠 㡰 �� 鼀 �盐鼀㜠҈  � 鼀 �盐鼀㜠 ᆠ㡰 �� 鼀 �盐鼀㜠  � 鼀 �盐鼀㜠҈ 㡰 �  b d



�

㡰 꾀ᆠᨨ   矄ᨨ  ᨨᆠ � ҈�ᆠ鼀 ᆠ ᆠ 鼀�ᨨᨨ  ᨨᆠ � ᆠ鼀├犨�  �ᨨ�ᆠ  矄PQ   RS  盐 矄 �  �ᆠ �ᆠ�ᨨ 泐ᆠ鼀矄矄 ᨨ犨   �矄 ᆠ犨

  矄 鼀�ᨨ�矄ᆠ鼀꾀 盐�� ᨨᆠABᨨ �� ҈ᆠ鼀�矄ᆠ ᨨ  ᨨ�ᆠ �矄PQᨨ    矄 �矄 ᆠᨨ ᆠ鼀 ᨨ鼀  矄ᔼ  AἘ B Ἐ �矄  �鼀�  ᆠ�ᨨ  ᨨ鼀  矄  ᆠ�ᨨ

ᨨ鼀 鼀�ᨨ �   �矄 ᆠᨨ  AἘ B Ἐ  ᨨ鼀  ᨨᨨ  鼀�ᨨ ᨨ� �矄鼀� � �ᆠ�ᨨ 꾀矄ᨨ ᨨᆠ ᨨ矄��ᨨ  ᨨ  A Ἐ    B Ἐ  犨�  矄ᆠ ᨨ   ᨨ�ᆠ �矄RS ᲼㜠㝐├矄桌

䰘

10 Subjective Problems 꾀矄矄ABCDᨨ ҈ᆠ鼀犨�   矄犨ᨨ矄鼀矄�矄S҈ S矄 犨� �  �ᆠ�矄矄矄ᨨ ⼄盐 �ᆠ├ 矄矄

 �矄 ᆠ犨  矄�矄�矄鼀鼀POQ�矄 �   �ᆠ盐ᨨ  AB 矄矄� � ᨨ盐� O  鼀� ᨨ� ᨨ S҈ S꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� 矄ᨨ盐ᆠ�矄 ├ 和ᆠ鼀ᨨ犨P   鼀  ᨨ鼀   矄矄 ᨨ �盐鼀�  矄�矄矄矄 ᨨ犨 �   ��盐ᨨ犨ᔴᆠ盐  ᨨ矄��ᨨ ᨨ  ᆠ ��  � �ᨨ  ᨨ 犨 CD犨� 矄ᆠᨨ � OQᨨ犨�⼄盐� �矄ᨨ盐 � ᨨ 矄矄  � 盐ᨨOQ ᆠ ��  � � �矄 ᨨ盐 ᨨQᔴᆠ盐  ᆠ��  ᨨ   �⼄盐�  ᲼҈㜠�㝐├矄桌



A

㡰 꾀�矄矄ᨨ  ᆠ��  ҈��矄ᆠᨨ 犨�   � 泐ᨨ  �ᆠ├ 矄矄  ᆠ��  ҈��  ᨨ 犨 � l� �� ��矄� ᆠ�   ᨨ鼀泐 ᨨ  泐ᔼ�矄泐 ᆠ  盐   ᨨ犨矄盐 ᆠᨨ  泐  犨ᨨ ᆠ 泐矄 �  ␔� ᆠᨨ ��ᨨ  ᨨ �ᆠᨨ 矄盐ᆠ� �   ᆠᔼ l㦨 鼀ᨨ�  矄盐ᨨ  ᨨ犨 �ᆠ  泐矄�  ᆠᨨ 矄盐ᆠ�泐 ᲼㜠㝐├矄桌

D

S҈ P

Q

O S

ᆠ鼀 鼀

S

҈ᆠ鼀 B

C

Answer Key Topic-1 : Wavefront, Interference of Light, Coherent and Incoherent Sources ҈ ҈҈

㡰 㡰

 㡰 ҈ ᆠ㡰

 ᆠ㡰 ҈ ᆠ㡰

 㡰

� ᆠ㡰

 㡰

䰘 㡰

 ᆠ㡰

黨 㡰

҈ 㡰

Topic-2 : Young's Double Slit Experiment ҈ ҈҈ ҈ ҈ 

㡰  㡰  㡰 ҈ ᆠ㡰 ҈ 㡰  㡰  꾀和쟼  쟼  꾀㜠矄錐㜠⼄錐ᔴ㜠錐㜠矄㡰

㡰 㡰 㡰  㡰

 ҈  

㡰 � ᆠ㡰 ᆠ㡰 ҈� ᆠ㡰 㡰 � ᆠ㡰 ᆠ㡰

 ҈  �

ᆠ㡰 䰘 ᨨ 盐矄㡰  㡰 ҈䰘 ᆠ㡰 ҈ 㡰 䰘 㡰  㡰  ᆠ㡰 䰘

㡰 㡰 黨㡰  㡰

黨 㡰 ҈ 㡰 ҈黨 㡰  ᆠ㡰 黨 䰘�㡰 

Topic-3 : Diffraction, Polarisation of Light and Resolving Power ҈ ҈҈ ҈

㡰 ᆠ㡰 ᆠ㡰

 㡰 ҈ 㡰  㡰

 㡰 ҈ 㡰  ᆠ㡰

 㡰 ҈ 㡰  㡰

� ᆠ㡰 ҈� 㡰 � 㡰

 ᆠ㡰 ҈ 㡰  ᆠ㡰

䰘 㡰 ҈䰘 㡰 䰘 㡰

 㡰 ҈ 㡰  㡰

黨 㡰 ҈ 㡰 ҈黨 㡰  㡰 黨 ҈黨㡰

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈ 䰘

� 黨 㡰

 꾀㡰® 㡰錐 㡰® 㡰錐 ᔴ㡰® 㡰錐 㡰® 㡰 ⼄㡰 㡰錐

 㡰

 ᆠ㡰

� 㡰

 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-276

Physics

Dual Nature of Radiation and Matter

25

Topic-1 : Matter Waves, Cathode and Positive Rays 1 ҈





MCQs with One Correct Answer

꾀 ᆠᨨ  ᨨ盐泐�ᨨ �   �盐鼀�ᨨ  졔졔㡰  ᨨᨨ  � � 矄鼀├� �ᆠ �泐 �ᨨ

犨  �矄ᆠ� 㜠ᨨ��犨 � 矄ll졔졔  l�矄 ᲼㝐� 和 ᔼ㡰桌 㡰 l> l졔졔>l 㡰 l< l졔졔㦨l ᆠ㡰 l> l>l졔졔 㡰 l< ll졔졔 꾀矄矄盐鼀� �   �ᨨ�  鼀ᨨᆠ盐 �矄 鼀ᨨ� � 犨� 鼀矄ᨨᆠ�泐  ⧤   㜠ᨨ�� 犨 �  ᨨ

�ᨨ � 鼀ᨨᆠ盐�矄ᆠᨨ矄ᨨ ෌�  �ᨨ� 鼀ᨨᆠ盐犨�� 맔҈├�ᨨ 鼀

ᆠᨨ 矄 ҈맔҈⏌⧤ ᆠ├ᆠᨨ 矄 맔҈矄㡰 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 处 㡰 处 ᆠ㡰 处 㡰 处

�



䰘

m 鼀ᨨ� �ᨨ � x㜠 �矄犨�  ᨨᆠ�泐vᆠᨨ� 矄矄�ᆠ泐犨�  ᨨ �ᆠB矄

�ᆠAᨨ 鼀矄矄 mA =

m  ᔼ ᨨ �ᆠ矄鼀ᨨᨨ � x㜠   �矄     ᆠᨨ�矄�ᨨ    ᆠ  � Dl  �  㜠ᨨ�� 犨 � ᨨ �ᆠA� 鼀矄ᨨ �矄 㜠ᨨ��犨 � l㡰 ᨨᆠᨨ�矄�ᨨ �矄 [㝐� Sep.04, 2020 (I)]

� �鼀矄矄 mB =

㡰



 Dl = l  

㡰

㡰

l  ҈+

l

㡰 ҈+



e E t  m v l

e E t  e E t +  m  v  m v 꾀�ᆠ � �矄 ᨨ鼀  盐 ᨨ ᆠᨨ鼀泐� 矄�ᆠ ᆠᨨ�矄�ᨨ  ᨨ  �ᆠ矄 �x  �y � � 㜠ᨨ�� 犨 � 矄 �gx  �g泐矄ᆠ�泐 ᔼ x   y 犨 鼀ᨨ� � �  ᨨᨨ矄� �ᆠ�ᨨ 矄      㜠ᨨ�� 犨 � ᨨ ��矄 ᲼㝐� 黨꾀҈黨 ᔼᔼ㡰桌 ҈+



e E  t  m v l

ᆠ㡰

� Dl = l  

ᆠ㡰 Dl = l  㡰 Dl = l  꾀�ᆠ�矄鼀ᨨ� ���鼀矄矄 矄矄 ᆠᨨ   �ᨨᨨ   㜠ᨨ��犨 � ᨨ  �ᆠᨨ ᨨ  ᆠᨨ �矄҈䰘맔҈ 鼀矄矄ᨨ  �ᆠ�矄 ᆠᨨ矄ᨨ [㝐� Sep.02, 2020 (II)] 㡰 맔҈䰘├� 㡰 黨҈맔҈҈├� ᆠ㡰 ҈맔҈├� 㡰 黨䰘맔҈├�

꾀�ᆠ鼀ᨨ� �犨�  ├� �ᆠ �泐쟼 矄 ᨨ�� 犨 � lᔼ  �泐D쟼�矄  ᨨ�矄 �泐 犨 � l ᆠᨨ鼀 盐ᨨ D쟼�矄 ᲼㝐� 黨  ᔼ㡰桌  㡰 쟼 㡰 쟼 ᆠ㡰 쟼 㡰 쟼 꾀 ᆠᨨ ᨨ 鼀矄矄鼀 鼀� �盐 ᨨ ᆠ �e� ��泐 矄�矄ᆠᆠ 泐ᆠᨨ 矄 ᆠ�ᆠ � 쟼  ᨨ ᆠ  �ᨨ  㜠ᨨ��犨 � ᨨ  �矄ᆠᨨ �鼀t �� ᨨ� ���矄�ᆠ ᆠ矄�矄 ᲼㝐� 黨  ᔼᔼ㡰桌 h  e  쟼 㡰 㡰 e쟼 t h -h h ᆠ㡰 㡰  e  쟼  e  쟼  r 꾀 ᆠᨨ  鼀矄矄鼀㡰犨� � ��ᨨᆠ�泐 v = v�ˆ + v ˆ �矄 r �  ᆠ�ᆠ �  E = - E kˆ ᔼ l  �矄� �� 㜠ᨨ�� 犨 � ᨨ ᆠᨨ �矄 㜠ᨨ��犨 � �鼀 t�矄�� 泐 ᲼㝐�   ᔼᔼ㡰桌



 

g xg y g xg y 㡰  g + g 㡰  g - g  ᆠ㡰 g x - g y x y x y

㡰 g x + g y

WWW.JEEBOOKS.IN

P-277

Dual Nature of Radiation and Matter

黨

꾀�ᆠ꾀ᨨ 鼀矄矄�鼀 ᆠ ��⼄�矄ᆠᆠ 泐 ᨨ � �  ᆠᨨ �꾀 ᨨ �ᆠᨨ 鼀矄矄�鼀   ᆠ ��⼄ �矄 ᆠᆠ  泐 ᨨ � �  ᆠ ᨨ

l � �ᨨᨨ  㜠ᨨ��犨 �  A �矄 lB ᲼㝐� ҈ ҈黨 ᔼ㡰桌 ҈

㡰 ҈ 㡰 䰘 ᆠ㡰 ҈҈ 㡰 䰘 ᔼ   ᨨ��犨 � ᨨ  ᆠᨨ �矄⼄盐ᨨ҈ �鼀矄 犨 � ᨨ  ᨨᨨ ᨨ  ⼄盐 ᆠ泐맔҈҈     矄 ᨨ ᆠᨨ �矄⼄盐ᨨ 和 ᨨ �� 㦨맔҈鼀⏌矄㡰  ᆠ├矄ᆠᨨ 矄 㦨맔҈矄 㝐矄矄ᨨ ᆠᨨ 㦨黨҈맔҈҈├�㡰᲼㝐� ҈҈ ҈黨 ᔼ㡰桌 㡰 ҈҈맔҈鼀⏌矄 㡰

҈҈

ᆠ㡰 ҈맔҈鼀⏌矄 㡰 ҈�맔҈鼀⏌矄

犨ᨨᆠᨨ 矄  鼀ᨨ� � 犨�  ᨨ 㜠��矄�ᆠ 矄 矄  �ᆠ盐ᨨᆠ ᨨ ᔼ ᆠᨨ矄ᨨ � � ᨨ�� 犨 � 矄l҈ l � ᨨ��犨 � �

  鼀ᨨ   ᆠᆠ  ᨨ �ᆠ ᨨ 鼀矄矄�矄 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰 lᔴ㝐㦨l҈㦨l

㡰

҈ ҈ ҈ = + l҈ l҈ l 

l҈l 

æ l + l ö lCM = ç ҈ ÷ è  ø 꾀�ᆠ꾀ᨨ 鼀矄矄鼀 � ��ᨨᆠ�泐ᆠᨨ� 矄犨� m �ᆠᨨ 鼀矄矄 犨 �ᆠ �矄矄 ᆠᨨ�矄�ᨨ �矄    ᨨ    矄�ᆠ  �ᨨ ᨨ    㜠ᨨ�� ᆠ㡰

҈

҈䰘맔҈鼀⏌矄

lCM =

l҈ + l 



犨 � 矄 l꾀 ᨨ lB   ᆠᨨ�矄�ᨨ �矄᲼㝐� ҈䰘桌 㡰

lA  = lB 

㡰

lA ҈ = lB 

lA lA ҈ = 㡰 l =  lB  B 꾀鼀ᨨ ᆠᨨ 矄� �� x㜠 �ᆠ�ᨨ  矄 ᨨ 矄�ᨨ 犨�    矄 ��盐㡰ᔼ  矄矄� � 矄�

ᆠᨨ ᆠ⼄盐�矄鼀ᨨ鼀 盐鼀泐�   泐㜠 �ᆠ�ᨨ  

ᨨ鼀ᨨ�泐ᨨ ᆠᨨ 矄矄矄� � ᨨ盐�  矄� �矄  ᆠ├矄ᆠᨨ 矄 㡰 ᲼㝐� 졠 � 꾀�҈҈�桌

ᆠ㡰

҈

Ӹ 

㡰 泐 > 㡰 泐  ᆠ㡰 泐  ;  㡰 泐 >> ҈ ᨨ犨 �ᆠ ᨨ   ᨨᨨ犨� ��ᆠ矄犨��鼀ᨨ矄 � �ᆠ盐 ᨨ �鼀 泐� 泐  㜠ᨨ���ᨨ 矄 �䁸 ᲼㝐� 졠 � 꾀�黨҈桌 㡰  ᆠᨨ

㡰 ᨨᨨ

ᆠ㡰  a㜠�ᆠ 㡰  盐矄�ᆠ ҈� 쟼ᆠᨨ 矄ᆠᆠ  ᨨ盐� ᨨ � �  ᆠ  ᨨᨨ 矄ᆠᆠ  ᨨ盐� ᨨ � �  ᆠ   㜠ᨨ��犨 � 矄le lp ᨨᆠᨨ 矄

l  ᨨᨨ 矄矄ᆠ�泐 �ᨨᨨ  e �矄�� 泐 lp �� me�矄鼀矄矄ᨨ ᆠᨨ  mp�矄鼀矄矄ᨨ ᨨᨨ 㡰 ᲼㝐� 졠 � 꾀�҈桌 㡰

mp le = lp me

㡰

me le = lp mp

ᆠ㡰

le ҈ me = l p  mp



mp le = lp me

҈ 꾀ᨨᨨ  矄├� �ᆠ �泐E㦨҈├犨 �ᆠ �矄⼄盐ᨨ  ᨨ  ᨨᨨ  犨 � ᨨ  ᨨᨨ �矄l  ᨨ ᨨᨨ �矄l҈ �ᨨ ᨨ l⏌l҈�矄ᨨᨨ�ᨨ ᨨ ᲼和桌 ᆠ㡰 E҈ 㡰 E ҈⏌ 㡰 E  㡰 E ҈⏌ ҈䰘 꾀�ᆠᨨ 鼀矄矄M矄 ᆠ泐矄� ᨨ犨ᨨ�ᆠ矄ᨨ 鼀矄矄矄m҈ m � � ᨨ 㜠 ᨨᨨᆠ��矄 �ᨨ ᨨ   ᨨ��犨 � 矄ᨨ  �ᆠ矄l҈⏌l�矄 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 m҈⏌m 㡰 m⏌m҈ ᆠ㡰 ҈



m ⏌ m҈

2 Integer Value Answer ҈ 꾀 a㜠�ᆠ ᨨᨨ ᆠᆠ  ᨨ鼀矄泐 ᨨ � �  ᆠᨨ ҈꾀  �矄 � ᨨ�� lp 犨 � 矄la  l矄ᆠ�泐 �ᨨ ᨨ la   矄� ��矄 ᲼҈桌 10 Subjective Problems ҈黨 ᨨ � �泐ᨨ �ᆠᨨ 鼀矄矄m�矄�� 泐 ì E 錐  £ x £ ҈ü V x㡰 = í  ý x >҈ þ î 錐 l҈ l  㜠ᨨ��犨 � 矄ᨨ  �ᆠ 犨    £ x £ ҈  x>҈矄ᆠ�泐ᔼ  ᨨ �泐 ᨨ �ᆠ�矄E � l҈⏌l ᲼�㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-278

Physics

Topic-2 : Photon, Photoelectric Effect X-rays and Davisson-Germer Experiment 1 ҈

MCQs with One Correct Answer

෌�  ��盐矄 ᨨ犨矄 犨 ᨨ� 矄�   ᨨᨨᆠ�ᆠ  ᆠ �鼀  ᨨᆠ� 鼀 鼀� �鼀盐鼀 �泐 ᨨᆠ�ᨨ ᨨ ᆠᨨ  ᨨ鼀�矄矄盐 ᆠ�矄  ᆠ├矄ᆠᨨ 矄  h㦨맔҈矄㡰 [Main Sep.04, 2020 (I)]



矄ᨨ 㡰

Ӹ



㡰

䰘

 ��㡰 꾀 � 

f ҈  㡰

㡰 䰘 㡰 �黨 ᆠ㡰 ҈黨 㡰 ҈ ᔼ  ᨨᨨᆠ�ᆠ ᆠ �鼀  � ᨨ 矄ᨨ� � ᨨ �V矄盐矄ᆠ�ᨨᆠᨨ 犨 � ᨨ�  �矄 矄 ᨨ犨 �   ��盐꾀矄 �  矄�泐ᨨ � ᆠ�   ��ᨨ

�矄� ᆠ矄  ᲼Main 和 ᔼᔼ㡰桌 V

q





҈⏌l

㡰 和�� � 矄 � 矄ᨨ��  㡰 和ᨨᨨ  矄�� � �鼀ᨨ矄 ᆠ㡰 和�� � 矄 � 矄ᨨ  㡰 ෌  ᨨ矄 ᨨᆠ  � ␔   犨 � ᨨ  ��ᨨ  � �ᨨ 鼀�矄 ᆠ  �  ᨨ鼀� 鼀ᨨ 鼀 鼀 �鼀盐鼀├� �ᆠ �泐 ᨨ   ᨨᨨᆠᨨ 矄ᆠᨨ鼀矄 �鼀矄� 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  鼀�矄ᆠᨨ矄ᨨ [Main Sep. 03, 2020 (I)] 㡰 ҈ 㡰 ҈ ᆠ㡰 � 㡰 ҈

犨ᨨ矄ᨨ盐ᆠ矄ᨨ �� 鼀�㜠泐矄ᨨ 犨 � ҈ 鼀 �矄��� ᨨ 犨 � � 鼀矄ᆠ�泐ᨨ   矄ᨨ盐ᆠ矄鼀��� ᨨ  矄鼀ᨨ犨␔ �ᨨᨨ   盐鼀  矄�泐ᨨ  ᨨᨨ 矄ᨨ 㜠泐矄ᨨ  盐鼀  矄�泐 ᨨ   ᨨᨨ 矄 ᨨ    �矄� ��  ᨨ    ��

犨 � 矄�矄 ᲼Main 和 ᔼᔼ㡰桌 㡰

�



҈

㡰 ҈҈ 㡰  ᆠ㡰 ҈ 㡰 ҈ ␔   ᨨᨨ ᨨ  �泐矄�├矄 矄盐 ᆠᨨ  鼀 A   ᆠ   ᨨᨨᆠᨨ 矄  鼀 �鼀盐鼀 ├� �ᆠ �泐TA  㜠ᨨ��犨 � lA  鼀 �鼀盐鼀├� �ᆠ �泐ᨨ  ᨨᨨᆠᨨ 矄� ᨨ鼀 ᨨ 鼀B泐 ᨨᨨ ᨨ  �泐��矄 T B 㦨 T A ҈�㡰 ᔼ    㜠ᨨ��犨 �  ᨨ  矄  ᨨᨨᆠᨨ 矄lB㦨lA   犨ᨨ├ 盐 ᆠ�ᨨ ᨨ 鼀 �矄 ᲼Main  ᔼ桌 㡰  㡰  ᆠ㡰 ҈� 㡰 

矄ᨨ� �ᨨ � � ᨨ㡰矄 盐 ᆠ�ᨨ ᨨ  ⼄盐 ᆠ泐 v㡰 ᨨ矄ᨨ �盐鼀鼀��矄矄 ᨨ犨 �   ��盐 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ 矄ᨨ �盐鼀 ᨨ鼀  ᨨ �   ��盐犨� ෌�  ᆠ├矄ᆠᨨ 矄  h㡰㦨맔҈矄ᆠᨨ

ᆠ �e㦨҈맔҈҈黨ᔴ㡰 ᲼Main ҈꾀҈黨ᔼ桌

҈ 㡰 � �

ᆠ㡰

҈ �

㡰 �

 ��ᨨ 犨� 犨 � �҈处 矄ᨨ 鼀矄盐 ᆠ ᨨᨨ 盐ᆠ ᨨᨨᆠᨨ 矄 ᆠᨨ 矄鼀 ᨨ  盐 � ᨨ鼀鼀� �ᆠ � ᨨ 맔҈ ᔼ   �盐矄ᨨ   �矄ᆠ�ᆠ盐  ᨨᨨ犨 泐 ᆠᨨ 矄�矄҈鼀鼀  犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  鼀�矄ᆠᨨ矄ᨨ ᲼Main 黨   ᔼ㡰桌



黨

㡰 ҈ 㡰 ҈ ᆠ㡰 ҈黨� 㡰 ҈ 꾀鼀␔矄ᨨ矄犨 � ᨨ � 鼀 

盐鼀ᨨ  ᨨᨨ 矄 犨�鼀� 矄ᆠᨨ �矄 ᲼෌�  ᆠ├矄ᆠᨨ 矄  㦨맔҈矄矄 ᨨ ��  c㦨맔҈鼀⏌矄桌 ᲼Main ҈꾀҈黨 ᔼᔼ㡰桌 ҈� ҈ 㡰 �맔҈ 㡰 ҈�맔҈ ᆠ㡰 맔҈҈ 㡰 ҈맔҈҈

ᆠ�ᆠ � ᨨ �� 犨�矄�� 矄 r æ p x ö N - p ´  ´ ҈҈ t ÷ x$ E = ҈ ᆠᨨ矄 ç -䰘 è � ´҈ ø C

�矄��  矄ᨨ 鼀ᨨ 犨ᨨ├ 盐 ᆠ�ᨨ   矄ᨨ� �ᨨ �ᨨ   ᨨᨨ㜠ᆠᨨ 矄�矄

҈䰘� ෌� 쟼 � 㡰㦨 ( ᲼㝐� 黨꾀�҈黨 ᔼ㡰桌 l � 处 ) 㡰  㡰 䰘 ᆠ㡰  㡰  ҈ ␔  ᆠ�  ᨨᨨ矄 矄�矄�矄盐 ᆠ�矄�盐鼀�  犨� 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ  ⼄盐 ᆠ泐v 矄ᨨ� �ᨨ � ᨨ    ᨨᨨ ᆠ盐  �矄  ⏌ ␔     矄盐 ᆠ �矄 �盐鼀�  泐鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ  ⼄盐 ᆠ泐v⏌  矄ᨨᨨ� �ᨨ ��矄  矄 ᨨ  ⼄盐 ᆠ泐 ᨨ  ᨨᨨᆠ�ᆠ鼀�矄矄�ᨨ �矄 ᲼Main ҈ ҈黨ᔼᔼ桌 �v  v 㡰 㡰  

WWW.JEEBOOKS.IN

P-279

Dual Nature of Radiation and Matter

v  ᔼ  ᨨᨨᆠ�ᆠ �鼀  犨 � ᨨ  �� � ᆠ�   ᨨ 鼀�矄ᆠ  �  ᨨ鼀 鼀ᨨ 鼀  ᆠ矄�

 矄ᨨ� �ᨨ ��矄ᆠᨨ矄ᨨ ᲼Main ҈҈ ҈黨ᔼᔼ桌 æ ᆠ ö çè = ҈ 鼀㜠÷ø  㡰 � 㡰 ҈� ᆠ㡰 ҈ 㡰  꾀 鼀  ᨨ   ҈ 맔 ҈ 鼀 �矄 �盐鼀�   泐  ��ᨨ ᨨ �  矄�泐҈鼀␔⏌鼀 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ   鼀�矄�  �泐ᨨ  � ᆠ�   ᨨᨨ 矄�矄҈  ᨨ 泐҈奠ᨨ �ᨨ 盐ᆠ矄 ᨨᨨᆠᨨ 矄  盐鼀 ᨨ 鼀�  ᨨᨨᆠᨨ 矄矄ᆠᨨ   �鼀 �鼀盐鼀  �泐矄ᆠ�泐犨� ᲼҈㦨҈맔҈҈黨桌  ᲼㝐�  ҈  ҈黨 ᔼᔼ㡰桌 㡰 ҈҈ ҈ 㡰 ҈҈ � ᆠ㡰 ҈҈҈ � 㡰 ҈҈ � 和盐 ᆠᨨ ᆠ� 鼀�矄 �矄�盐鼀�  犨� �� ᨨ 犨 � l҈㦨� 鼀   泐�� ᨨ 犨 � l㦨� 鼀ᔼ�矄 ᨨ盐   鼀 �鼀盐鼀矄 ᨨ    ᨨᨨᆠᨨ 矄�  犨ᨨᆠ矄矄 � 泐 ᆠᨨᨨ  㡰

犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  鼀 � 㡰�矄ᆠᨨ矄ᨨ ҈ 쟼 �泐ᨨ  ᨨᨨ 㦨 l � 鼀  㡰 ( ) ᲼Main 黨 ҈黨ᔼ桌 㡰 ҈ 㡰 � ᆠ㡰 � 㡰 ҈

鼀� �ᆠ � 矄矄ᨨᆠ� 犨� �� 犨�矄��

   ᨨ���  泐 㦨᲼矄� ҈맔҈䰘㡰ᆠ졔矄� 맔҈䰘㡰ᆠ桌 ᔼ  �矄��  矄ᨨ 矄� � �犨ᨨ├ 盐 ᆠ�ᨨ

ᨨ 䰘犨 犨� 鼀 �鼀盐鼀├� �ᆠ �泐ᨨ    ᨨᨨᆠᨨ 矄䁸 ᲼Main 黨 ҈黨 ᔼᔼ桌 ᆠ㦨맔҈鼀矄҈  㦨맔҈㜠矄㡰 㡰  㡰 ҈� ᆠ㡰 � 㡰 䰘䰘 꾀 ᆠᨨ 鼀�矄ᆠᆠ 泐ᨨ � �  ᆠᨨ �鼀�ᆠ�ᨨᨨ 盐ᆠ㜠泐矄ᔼᨨ 盐ᆠ矄ᆠᨨ � 盐ᨨ盐矄 矄犨矄ᆠ ᆠ�矄�ᆠ㜠泐矄ᔼ l鼀� �矄 矄鼀矄ᨨ矄矄� 犨 � ᨨ 㜠泐�  矄ᆠ盐鼀 ��ᨨ ᨨ ᨨ�l鼀�

᲼Main ҈䰘桌 犨� ᨨ��矄ᆠᨨᆠ泐矄  � 

ᆠ㡰 v

҈҈

҈

҈

҈

҈�

㡰

ᆠ㡰 ҈



㡰



鼀 �鼀盐鼀ᨨᆠ�泐ᨨ   ᨨᨨᆠᨨ 矄鼀�  ᨨ鼀  矄盐 ᆠ�矄犨  �� ᨨ  ⼄盐 ᆠ泐  矄ᨨ 鼀 矄盐 ᆠᔼ  � ᆠ�   ⼄盐 ᆠ泐�矄� ᆠ矄 ᨨ   鼀 �鼀盐鼀ᨨᆠ�泐ᨨ  ᆠ  ᨨᨨᆠᨨ 矄犨� ᲼Main 졠 � 꾀�҈䰘桌

㡰  㡰 矄矄    ᆠ㡰 鼀ᨨ    㡰 ⼄盐ᨨ  ҈䰘 꾀  ᨨᨨᆠ�ᆠ 鼀� � � 犨ᨨ├ 盐 ᆠ�ᨨ  f �矄 æ ᆠ ö �盐鼀�  犨�  ��  ᨨ 犨 �  l ç l < f ÷   ø è 矄矄 ᨨᨨᆠᨨ  矄 ᨨ��犨 � l 꾀 ᆠ  �� 犨 � ᨨ  � ᆠ�  �� 泐Dl 矄盐�

ᆠ  �Dl � l    �ᨨDl ⏌Dl�矄ᨨᨨ�ᨨ ᨨ ᲼꾀 ҈䰘桌

㡰 l ⏌l ᆠ㡰

l ⏌ l

㡰

l  ⏌ l

㡰

l  ⏌ l

҈  ��ᨨ ᨨ 犨 � l�矄� ᆠ�  ᨨ  ᨨᨨᆠ  矄矄鼀� ᆠᨨ  矄矄 ᔼ  犨 � �矄 l ᆠ  � ᨨ   矄 ᨨ   矄矄鼀� ᆠᨨ

 犨� ᲼Main ҈桌 ҈

㡰

æ  ö = ç ÷ èø

҈

㡰

æ  ö = ç ÷ èø

҈

҈黨

҈

æ  ö æ  ö ᆠ㡰 >  ç ÷ 㡰 <  ç ÷  è ø èø 꾀  ᨨᨨᆠ�ᆠ 矄盐 ᆠ �矄 �盐鼀�   矄盐ᆠᆠ矄矄�泐 泐 l 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ ��  ᨨ  犨 � 矄 l    ᔼ     鼀 �鼀盐鼀├� �ᆠ �泐ᨨ  鼀�  ᨨᨨᆠᨨ 矄�

 矄ᆠᨨ ᆠ矄�矄�鼀矄 �   �矄ᆠ矄 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  矄盐 ᆠ�矄 ᲼Main 졠 � 꾀�҈҈桌

㡰

ᆠ l

㡰

ᆠ l

ᆠ㡰

ᆠ l



 ᆠ l

 ᔼ  �矄ᨨ�ᆠ �鼀 ᨨ 鼀�  ᆠ├Ἐ矄ᆠᨨ 矄  鼀 矄盐 ᆠ 犨矄 � �  犨�  ��  ᨨ  �   犨 � 矄  鼀�   ᨨᨨᆠᨨ   ��矄 犨 鼀矄盐 泐泐� �矄ᨨ� �ᨨ �    ᨨ   犨 �  l㡰 ᨨ � ᆠ�   ��      ᆠᨨ矄ᨨ � �矄ᨨ� �ᨨ � 㡰�� ᨨ犨 l m鼀㡰  ᨨ㡰   �

 ҈ 

෌�  ᆠ㦨맔҈鼀矄҈ 㦨҈맔҈҈黨ᔴ ᆠ├Ἐ矄 ᆠᨨ 矄  � 盐 �矄ᨨ 矄㡰 ᨨ盐  ᨨ鼀矄盐ᆠ   �鼀 �矄 ᲼꾀 ҈桌 㡰 맔҈ 㡰 맔҈ ᆠ㡰 맔҈ 㡰 맔҈ ҈ 㝐ᆠ �矄㜠ᔼ 盐 鼀 쟼 �鼀 㡰犨� �矄㜠ᔼᔼ �矄 ᆠᨨ ᆠ盐矄�ᨨ 㡰 矄ᆠ ᆠᨨᆠᨨ�ᨨ  ᨨ鼀 ᆠ ᨨ�ᆠ矄 �� ᨨ犨 �矄 ᲼Main ҈�桌

WWW.JEEBOOKS.IN

EBD_8341 P-280

Physics

�矄㜠ᔼᔼ �矄㜠ᔼ 꾀  ᆠ├㜠 �㡰�ᆠ 盐ᨨ ��  쟼 �鼀   ᨨᨨ㜠ᆠ�ᆠ ��㡰�矄ᆠ �泐矄ᨨ ᨨ鼀  �鼀   ᔴ�矄ᨨ 㜠෌鼀 ���㡰␔ 盐ᨨ ᆠᨨ

 �鼀  �㡰和盐ᆠ盐ᨨ ᨨ鼀







�

㡰 꾀㡰㜠 ��㡰錐 㡰㜠 �㡰錐 ᔴ㡰㜠 ���㡰 㡰 꾀㡰㜠 �㡰錐 㡰㜠 ���㡰錐 ᔴ㡰㜠 ��㡰 ᆠ㡰 꾀㡰㜠 �㡰錐 㡰㜠 �㡰錐 ᔴ㡰㜠 ���㡰 㡰 꾀㡰㜠 ��㡰錐 㡰㜠 �㡰錐 ᔴ㡰㜠 ���㡰 꾀鼀ᨨ ��  矄犨ᨨ犨 � 矄ᨨ 黨䰘处 ҈处 犨� ᨨ�  矄�泐ᨨ 맔҈␔鼀⼄盐泐 �矄�盐 鼀ᨨ � 犨ᨨ犨 � 矄 鼀 矄 ᨨ鼀泐ᨨ

 ᨨ ҈ᆠ鼀ᨨ ᆠ 鼀�ᆠ矄盐 ᆠᨨ 犨ᨨ├ 盐 ᆠ�ᨨ

꾀矄矄盐鼀  �矄 ᨨᨨ矄矄ᨨ �� 泐 ᆠ�ᨨ

    ᆠ  ᆠ  ᨨᨨ  ᆠ矄 ᨨ  ᆠᨨ  

盐鼀ᨨ  ᨨᨨᆠᨨ 矄� � 矄�矄ᨨ �鼀泐 ᲼Main 졠 � 꾀�҈҈桌 㡰 맔҈҈҈ 㡰 黨맔҈҈҈ ᆠ㡰 ҈҈맔҈҈҈ 㡰 ҈�맔҈҈҈ 꾀鼀矄盐 ᆠ�矄�盐鼀�  泐�� ᨨ 犨ᨨ �   犨 � 矄 鼀 ҈ 鼀 鼀 �鼀盐鼀矄 矄ᨨ    ᨨᨨᆠᨨ 矄ᆠᨨ矄ᨨ � � ᨨ 矄 犨 � 矄  u҈ u矄ᆠ�泐ᔼ  �ᨨu҈u㦨҈ hc㦨҈

鼀 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  鼀�矄 泐 ᲼꾀 ҈桌 㡰 䰘 㡰  ᆠ㡰  㡰 � ᔼ lᔴ盐�矄 犨 � ᨨ ⧤a㜠泐� ᨨ ᆠᨨ ᨨ鼀�ᆠ

盐鼀黨㡰 l㝐ᨨ�矄 犨 � ᨨ  ⧤a㜠泐 � ᨨ 鼀ᨨ泐  盐鼀 ᨨ鼀�ᆠ 盐鼀㡰   �ᨨ lᔴ盐⏌l㝐ᨨ�矄ᆠᨨ矄ᨨ  ᲼꾀 ҈桌 㡰 ҈黨黨 㡰 ҈ ᆠ㡰 � 㡰 

 ᨨ ᨨ�ᨨ  ᨨᨨᆠ�矄├ �   犨 � lᨨ  ��  � �ᨨ  ᆠ ᨨ �矄� 盐泐ᆠ  �   ᆠ盐 ᔼᨨ   ᨨᨨᆠ�矄矄 ᨨᨨ犨矄᲼Main ҈桌





㝐꾀 㝐

҈⏌l

ᨨᨨ├� � � 矄泐ᨨ盐ᆠ 鼀ᨨ矄ᨨ�泐矄泐  㡰 ␔ᨨ├ 盐 ᆠ�ᨨ ᨨ 鼀�矄�   ᨨ 鼀꾀 㡰 ᨨ�� ᨨ ᆠ� 犨 �  � �ᨨ ᨨ 鼀 鼀 �鼀盐鼀├� �ᆠ �泐ᨨ ᆠᨨ 矄鼀�  ᨨ鼀꾀 犨��   ᨨ矄鼀�  ᨨ鼀 ᆠ㡰 ␔ᨨ├ 盐 ᆠ�ᨨ ᨨ 鼀꾀�矄�   ᨨ 鼀 㡰 和盐  矄 �矄 ᨨᆠᨨᆠ 䰘 꾀盐矄ᨨ �� ᨨ  盐�ᨨ ҈ 矄�矄矄ᨨ ᆠᨨ鼀泐 泐矄鼀ᨨᆠ� ��泐矄ᨨ犨ᨨ  盐矄�矄 鼀␔     矄  ᨨ  ��  �矄 맔҈ 鼀矄҈    �  鼀ᨨ鼀 盐鼀ᨨ  ᨨᆠ�矄 ᲼꾀 ҈桌 㡰 맔҈҈䰘├�鼀矄҈ ᆠ㡰 맔҈҈䰘├�鼀矄҈ 㡰 ҈맔҈҈䰘├�鼀矄҈ 㡰 黨맔҈҈䰘├�鼀矄҈   ᨨᨨᆠ�ᆠ ᆠ �鼀 矄 ᨨ鼀 盐矄� �  �  鼀矄⼄  � �犨ᨨ├ 盐 ᆠ�ᨨ 矄 fp 㦨fq㦨� fr㦨矄ᆠ�泐꾀��  鼀ᆠᨨ � � �犨 � 矄ᨨ �� 鼀� 鼀 �

鼀犨� ⼄盐�  矄��矄�盐鼀� 矄ᆠ ᨨ  矄

ᆠᨨᆠI㜠V�  ᨨ  �鼀 �矄 ᲼ ├hc = ҈  鼀桌 ᲼Main 黨桌 ᔼ

ᔼ  ⼄  㡰 

㡰



ᆠ㡰



졠 l l ᔼ   �鼀 ᨨ  ᨨᨨᆠ�ᆠ ᆠ矄盐  ᨨ矄 矄ᨨ� �ᨨ ��� 矄ᆠ�ᨨᆠᨨ  犨 � l ᨨ  � ᆠ�  ��  ᨨ犨ᨨ �  鼀矄꾀  矄 ᲼Main 졠 � 꾀��҈桌 矄 ᨨ犨 �   ��盐 졠



l





 ᔼ



ᆠ㡰

⼄  㡰 

 ⼄

㡰

l















㡰







黨 ␔ �ᆠ ᨨ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄␔ 졠෌�   ᆠᨨ  ᨨ 㜠泐矄�   ᨨ鼀㜠泐盐䁸 ᲼桌 㡰 ␔ � ᨨ ᆠ ᆠ�矄�ᆠ㜠泐矄 ᆠ矄矄犨 

 ᨨ鼀�ᆠ 盐鼀ᨨ  �� ᆠ矄矄 㡰 ᔴ盐㜠ᨨ  犨 �  ᨨ    ᆠᨨ � 盐ᨨ盐矄 㜠泐矄  矄ᨨ  ᨨ鼀�ᆠ 盐鼀ᨨ  � ᆠ㡰 ᔼ  矄�泐ᨨ  ᆠ ᆠ�矄�ᆠ㜠泐矄  矄ᨨ   ᆠ�ᆠᨨ犨�� ᨨ 㜠泐盐 㡰 ᔴ盐㜠ᨨ 犨 � ᨨ  ᆠᨨ � 盐ᨨ盐矄㜠泐矄  矄 ᨨ   �泐ᨨ  ᆠᨨ 矄�  㜠泐盐  쟼ᆠᨨ 矄犨�  㜠ᨨ��犨 � l ᨨ  � �  㜠泐盐 ᆠ盐㜠ᨨ 犨 � ᨨ  鼀� 㜠泐矄�矄 ᲼䰘桌

WWW.JEEBOOKS.IN

P-281

Dual Nature of Radiation and Matter

㡰

l =

mcl  h m  c  l 

㡰

l =

h mc

㡰 l  = l h ҈ Ka 犨 �  鼀�  泐  ᨨ鼀  ᨨ ᨨ鼀�ᆠ 盐鼀 Z㦨҈҈�矄l �  ᨨ鼀�ᆠ 盐鼀 ᨨ ᨨ鼀 鼀�矄 Ka ��ᨨ 犨� 犨 � l. ᲼�和桌 㡰 Z㦨 㡰 Z㦨 ᆠ㡰 Z㦨҈҈ 㡰 Z㦨  ᔼ  ᨨᨨᆠ�ᆠ �鼀  ᨨ ᨨ ��矄ᨨ �� 矄ᆠ盐  ᲼和桌 ᆠ㡰

l =

ᔼ ᔴ

 꾀 





㡰 A B犨�  �  �  矄��矄犨 �B C 犨�  �   ⼄盐 ᆠ�矄 㡰 B C犨�  �  �  矄��矄犨 �A C 犨�  �   ⼄盐 ᆠ�矄 ᆠ㡰 A B犨�  �  �  矄��矄犨 �A C 犨� ⼄盐 ⼄盐 ᆠ�矄 㡰 B C犨� ⼄盐�  矄��矄犨 �A B犨� 矄鼀 ⼄盐 ᆠ�矄

ᨨ � �  ᆠ� ᨨ 㜠泐盐�矄�├   ᆠ盐  ᨨ盐� ��矄mA    盐鼀ᨨ ᆠᨨ 矄矄�├� � �矄ᆠᨨ �矄 ᲼和桌 㡰  ´ ҈҈ 㡰 � ´ ҈  ᆠ㡰 ҈´ ҈҈䰘 㡰  ´ ҈҈�

�  矄�泐ᨨ 㜠泐矄 ᨨ鼀ᔴᨨᨨ� �盐�矄ᨨ �� 矄犨 � l矄矄 ᨨ犨 �   ��盐 鼀� �鼀盐鼀 犨 �  ᨨ盐 �矄lC  犨 � ᨨ  Ka�  �矄lK꾀矄 ᆠᆠ� �ᨨ��矄� ᆠ矄 ᲼҈和桌 㡰 lK㜠lC� ᆠ矄矄

ᔼ

㡰 lK㜠lC ᆠ矄矄 ᆠ㡰 lK� ᆠ矄矄 㡰 lK ᆠ矄矄 �

lᔴ

l⧤

l

쟼ᆠᨨ 矄犨�  �泐├� ᆠ�  ᨨ  盐 �矄 � ᨨ  㜠泐盐⧤㜠矄 ᆠᨨ 矄ᨨ 盐 �矄  䰘�├  �泐㜠泐矄鼀� 泐 盐ᆠᨨ � ᨨ 泐 ᲼和桌 㡰 ᆠᨨ � 盐ᨨ盐矄㜠泐矄ᆠ盐鼀 鼀矄矄 盐 �㡰犨� 鼀� �鼀盐鼀犨 � ᨨ ҈��处 㡰 ᆠᨨ � 盐ᨨ盐矄㜠泐矄ᆠ盐鼀 鼀矄矄 盐 �㡰犨� 犨 � 矄 ᆠ㡰  ᆠ ᆠ�矄�ᆠ㜠泐矄ᆠ盐鼀ᨨ 盐 �矄

㡰 ᆠᨨ � 盐ᨨ盐矄㜠泐矄ᆠ盐鼀 鼀矄矄 盐 �㡰犨�  鼀� �鼀盐鼀 犨 �  ᨨ  ҈��处     ᆠ ᆠ�矄�ᆠ㜠泐矄ᆠ盐鼀ᨨ 盐 �矄 

 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ 矄盐矄 ᆠ�矄 ᨨ �矄 犨 � ᨨ ��  ᆠ ᆠ盐矄 ᨨᨨᆠᨨ 鼀�矄矄�ᨨ

ᨨ鼀 �矄矄盐矄 ᆠ�矄ᨨ �鼀泐 ᲼҈黨黨和㜠㝐├矄桌 㡰 � 鼀 㡰  鼀 ᆠ㡰 ҈ 鼀 㡰  鼀 䰘 㜠泐矄ᨨ 盐ᆠ �  㜠泐盐ᨨ� ���

ᆠᆠ� �ᨨ� 犨 � ᨨ  ᆠᨨ � 盐ᨨ盐矄 㜠泐矄 矄盐矄 ᨨ鼀 ᲼҈黨黨和㜠㝐├矄桌 㡰  ᨨ ¥ 㡰 l 鼀� ᨨ ¥ 犨  l 鼀� >  ᆠ㡰  ᨨ l 鼀 犨  l 鼀 < ¥ 㡰 l 鼀� ᨨ l 鼀 犨   < l 鼀� < l 鼀 < ¥  鼀 �鼀盐鼀├� �ᆠ �泐ᨨ  ᨨᨨᆠᨨ 矄鼀� ᨨ鼀矄盐 ᆠ犨   ᨨᨨ 矄ᨨ  �泐 ᨨ ��矄  矄ᨨ� �ᨨ �� ᨨ�矄 ᲼҈黨黨䰘㜠҈㝐├桌 㡰  㡰  ᆠ㡰  㡰 ҈ 黨 꾀  �泐ᨨ �矄⼄盐� ᨨ鼀ᨨᨨ ᨨ   ᆠᨨ 矄 ᨨ鼀 盐 �盐鼀ᨨ鼀  �泐�  㡰 ⼄盐� ᨨ鼀ᨨᨨ  ᆠᨨ 矄 ᨨ鼀 盐 �盐鼀 ᨨ鼀�矄 ᲼҈黨黨�和桌 㡰  㡰 黨 ᆠ㡰 �҈ 㡰 䰘黨  㜠泐鼀ᆠᨨ鼀� � ᨨ鼀 㜠泐盐犨� 㡰 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ ᲼҈黨�㜠㝐├矄桌 㡰 � �犨 � 矄矄鼀  ᆠ� 鼀 �鼀盐鼀 犨 � ᆠ㡰 � �犨 � 矄�  ᆠ� 鼀� �鼀盐鼀 犨 � 㡰 � �犨 � 矄泐� �犨 鼀� �鼀盐鼀  鼀 �鼀盐鼀犨 � ҈ 矄 ᨨ矄犨 � ᨨ 㜠泐矄鼀�  ᨨ鼀 㜠泐 盐  矄 ᨨ

᲼҈黨㜠㝐├矄桌 㡰  ᆠ盐 �  盐 㡰  ᨨ�� ᨨ 盐 ᆠ㡰   盐ᨨ  �矄� 盐 㡰  ᨨ鼀�ᆠ 盐鼀ᨨ  �鼀� 2

Integer Value Answer

 꾀 ᆠ泐 ᆠ� �鼀�ᨨ ᨨ 鼀矄矄㝐鼀ᨨ盐  ᨨ  矄� � ᆠᨨ 矄�盐矄  矄� �㜠鼀矄矄 矄泐矄鼀 ᨨ   �盐 ⼄盐 ᆠ泐矄盐ᆠ  㦨҈m㜠犨� h 矄 ᆠ├矄ᆠᨨ 矄  N ᨨᨨ 矄ᨨ 犨 � l㦨p맔҈㜠鼀矄�├ 鼀�ᨨ 矄�鼀盐 ᨨ盐矄泐 ᨨ鼀� ᆠ�  ᆠ矄盐ᆠ   鼀�ᨨ �矄 �矄ᆠ 泐҈m鼀ᔼ  盐ᨨ N�矄x맔҈҈ 

 盐ᨨ x�矄힘힘힘힘힘힘 ᲼ᔴᨨ 矄�  矄� �矄鼀矄矄矄矄桌 ᲼꾀 ҈黨桌

 犨ᨨ├ 盐 ᆠ�ᨨ 矄ᨨ 和� 和ᨨ �盐鼀   矄ᆠ�泐 �ᨨᨨ  矄ᨨᨨ  矄ᨨ� � ᨨ �矄盐矄 ⼄盐 ᆠ泐ᨨ ᨨ和�ᨨ ᨨ 和ᨨ �盐鼀 �矄 ᲼꾀 ҈㜠ᔼ桌

WWW.JEEBOOKS.IN

EBD_8341 P-282



Physics

꾀矄�矄 ᨨ  �盐矄҈ᆠ鼀 犨ᨨ├ 盐 ᆠ�ᨨ 䰘�矄 矄盐矄   ᨨ鼀  � 矄盐� �  �  矄ᆠ ᔼ�矄 盐 ᆠᨨ � 盐ᨨ盐矄�盐鼀� �ᨨ ᨨ  鼀犨 � ��  꾀矄 ᨨᨨᆠᨨ 矄鼀�  矄 �矄ᆠ �   ᆠ⼄盐�矄  ᨨ �  鼀 �鼀盐鼀 盐鼀 ᨨ  ᨨᨨᆠᨨ 矄鼀�  ᨨ鼀 矄 �矄꾀´ ҈  犨  ҈꾀҈㡰 盐ᨨ � �矄 ᲼҈҈桌 3

�



䰘

Numeric Answer

꾀鼀 ᨨ ᆠᨨ 矄 ᨨ  �泐쟼 矄ᆠ矄 ᨨ鼀  � � �ᨨ鼀�ᆠ矄ᆠ� �ᨨ ҈处  �矄鼀 �鼀盐鼀�  矄�泐 ᨨᆠᆠ盐矄q㦨º  쟼 � 㡰�矄힘힘힘힘힘힘  ├ᆠᨨ 矄 h㦨맔҈矄҈㦨҈맔҈҈黨 ᆠᨨ 鼀矄矄m㦨黨҈맔҈҈├�㡰᲼㝐� 和� ᔼ㡰桌

 矄盐 ᆠ ᨨ   鼀 �矄 �盐鼀�    泐犨�  ᨨᨨ 矄ᨨ  ��矄E҈㦨 E㦨�矄ᆠ�泐

�ᨨᨨ 鼀 �鼀盐鼀矄 矄ᨨ   ᨨᨨᆠᨨ 矄鼀� �  犨ᨨᆠ矄矄�矄 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ  鼀�  㡰 �矄 힘힘힘힘힘힘힘힘힘힘힘힘힘힘힘 ᲼㝐� 和� ᔼᔼ㡰桌 ␔   ��ᨨ ᨨ 犨 � l�矄盐矄 ᨨ�盐鼀�  鼀�ᆠ矄盐 ᆠ 矄ᨨ� �ᨨ ��矄V␔    矄鼀矄盐 ᆠ�矄�盐鼀�  犨�  ��ᨨ ᨨ 犨 �

V l 矄ᨨ� �ᨨ ��矄  ᔼ   矄 ᨨ 犨 �  ᨨ   鼀�ᆠ 矄盐 ᆠ �矄 nl    盐 ᨨ  n 犨�  힘힘힘힘힘힘힘힘힘 [Main Sep.02, 2020 (I)]  꾀鼀ᨨ ᆠᨨ鼀� �ᆠ ��ᨨ ᨨ �  矄�泐맔 ҈�␔⏌ᆠ鼀 �矄ᆠᨨ鼀�矄 ᨨ 犨 � l㦨҈ 鼀ᔼ 矄 ᨨ鼀泐ᨨ 鼀 犨ᨨ├ 盐 ᆠ�ᨨ j 㦨㡰ᨨ 矄盐 ᆠ ᨨ ҈ᆠ鼀ᔼ ᨨ � ҈ ᨨᨨ 矄ᆠ矄 ᆠᨨ ᨨ

盐鼀ᨨ ᆠᨨ 矄ᆠ � ҈矄�矄҈x hc㦨҈ 鼀 㦨҈맔҈҈黨㡰  x�矄힘힘힘힘힘힘 ᲼Main 䰘 ᔼ桌 黨 ᔼ    ᨨᨨᆠ�ᆠ  �鼀    鼀 ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� 犨� ᨨ犨ᨨ W�矄� ᆠ�  ᨨ   ᆠ泐矄ᨨ� �ᆠ ᨨ ᨨ 犨ᨨ├ 盐 ᆠ�ᨨ �  ⼄盐 ᆠ泐ᨨ �� �矄盐矄ᨨ  矄 ᨨ  ⼄盐 ᆠ泐 矄ᨨ      ᨨᨨᆠᨨ 矄  鼀�  犨�  ���� ├� �ᆠ �泐꾀矄矄盐鼀   ᨨᨨᆠᨨ 鼀�矄矄�ᨨ

 �ᆠ� ᆠ泐�矄҈奠꾀ᨨ � �  ᆠᨨ �V�矄� 犨    ᆠ ᨨ      ᨨ  꾀   鼀� ᆠᨨ 矄  � ᆠ�   ᨨ鼀泐ᨨ     ᨨ     矄ᨨ   ᨨ  � ᆠ矄 ᨨᆠ 㦨 맔҈ 盐 ᨨ   �鼀ᆠ ᨨ    ᆠᨨ 矄  盐 ᨨ  n �矄 힘힘힘힘힘힘힘힘힘힘㝐矄矄ᨨ  ᆠᨨ m㦨黨맔҈҈kg ҈㦨҈맔҈҈黨J ᲼꾀 ҈桌

4 �

�҈

Fill in the Blanks

犨 � ᨨ ⧤a㜠泐矄ᨨ 盐ᆠ 泐 㜠泐盐 �矄䰘处 ᨨ鼀�ᆠ 盐鼀ᨨ   ᨨ 鼀�ᨨ   盐�矄 ᲼҈黨黨㜠㝐├矄桌 꾀ᨨ � �  ᆠᨨ ├�矄� ᆠᨨ矄矄 㜠泐 盐  鼀� �鼀盐鼀 犨 �  ᨨ  㜠泐矄 �  �矄处 ᲼҈黨黨㜠㝐├矄桌

� ᔼ  㜠泐盐ᆠᨨ 矄ᆠᆠ  ᨨ盐� ᨨ � �  ᆠᨨ ҈�ᨨ矄矄�├ᆠᨨ� 矄 ᨨ  鼀� 㜠泐� 矄�  盐�矄鼀⏌矄 ᲼҈黨黨㜠҈㝐├桌 � 犨 �  ᨨ   ᆠ ᆠ�矄�ᆠ㜠泐 ⧤ a  �  鼀�  泐 泐 ᨨ�  �├ 鼀  �矄  处  犨 � ᨨ   ⧤ b � 鼀� 泐 矄鼀鼀  犨� ᲼҈黨黨㜠㝐├矄桌 � ␔    盐鼀ᨨ ᆠᨨ 矄矄�├� �  ᨨ ᨨ 

㜠泐盐�矄� ᆠ矄  ᨨ  鼀� 㜠泐矄 � ᆠ矄矄犨 �犨   矄 矄ᨨ  ᆠᨨ 矄矄�├� �    ᨨ   � ᆠ矄    ᆠ盐㜠ᨨ 犨 �  ᨨ    鼀� 㜠泐矄 ᲼҈黨㜠㝐├矄桌 �� 鼀 �鼀盐鼀├� �ᆠ �泐ᨨ ᆠᨨ 矄鼀� �    ᨨᨨᆠ�ᆠ ᆠ�矄� 泐   ᨨ  ᨨ   � ᆠ�   ��ᨨ  ᲼҈黨㜠㝐├矄桌 � ᨨᨨ 盐ᆠᆠ ᆠ�矄�ᆠ㜠泐矄盐矄� � 盐 �矄 � �  㜠泐� ᨨ ᆠᆠ� �ᨨ�矄 ᨨ盐  �  힘힘힘힘힘힘힘힘힘힘힘ᨨ矄   �泐ᨨ   ᆠ ᆠ�矄�ᆠ ��ᨨ �矄힘힘힘힘힘 � � � �泐ᨨ  �

鼀ᨨ矄ᆠᨨ �  盐 �矄

᲼҈黨㜠㝐├矄桌 �矄├㡰 5

True / False

�䰘 ᔼ  ᨨᨨᆠ�ᆠ鼀�矄矄�ᨨ ᨨᆠ矄矄 鼀 �鼀盐鼀 �泐 ᨨ   ᨨᨨ㜠ᆠᨨ 矄� ᆠ矄矄犨� � ᆠ矄� ��  矄�泐 ᨨ  � ᆠ�  ��  ᲼҈黨㜠㝐├矄桌 �  ├� �ᆠ  �泐 ᨨ   ᨨᨨᆠᨨ 矄 鼀�  泐   ᨨᨨ矄 矄�� 矄盐 ᆠ  矄 ᨨ    �  矄�泐ᨨ    � ᆠ�   ��ᨨ  ᲼҈黨҈㜠㝐├矄桌 6

MCQs with One or More than One Correct Answer

�黨 ᔼ  㜠泐盐ᆠᨨ 矄鼀�  ᨨ鼀 �鼀  ᆠ ᨨ 㡰 ᆠ泐� �ᆠ盐 I ��  ᨨ 㡰 �矄 ᆠd ᨨ鼀  ᆠ ᨨ  ��矄├ᨨ �V ��  

  ᆠ ᨨ  矄盐� � �  鼀�矄矄�ᨨ  ᨨ  ᆠᨨ � 盐ᨨ盐矄  ᆠ ᆠ�矄�ᆠ㜠泐矄ᔼ   �鼀 ᆠ盐 I�矄 ᆠ矄 I ᨨ  ᨨ � �  ᆠV�矄� ᆠ矄 ᨨV    d 矄�ᨨ  �矄 ᆠd�矄 盐ᆠ ᨨ  

 㡰  ᆠ盐㜠ᨨ 犨 � 犨� 盐ᆠᨨ     犨 � 矄ᨨ  ᆠ ᆠ�矄�ᆠ㜠泐矄犨�鼀�

 矄鼀 㡰  ᆠ盐㜠ᨨ 犨 � 矄犨矄 犨 � 矄ᨨ  ᆠ ᆠ�矄�ᆠ㜠泐矄犨�鼀�  矄鼀 ᆠ㡰  ᆠ盐㜠ᨨ 犨 � 犨� 盐ᆠᨨ     �  矄��矄ᨨ  㜠泐矄犨� ᆠ矄 㡰  ᆠ盐㜠ᨨ 犨 � 犨�ᆠᨨ鼀犨ᨨ�鼀矄�   �  矄�泐ᨨ  㜠泐矄犨� ᆠ矄  �� ᨨ 犨 � l  矄ᨨ ᆠ ᨨ � 矄�  ᆠ盐盐鼀盐矄矄 ᨨ犨 �   ��盐 犨ᨨ├ 盐 ᆠ�ᨨ

ᨨ  ᆠ ᨨ 矄盐 ᆠ�矄f   ᨨ �矄犨�鼀矄 ᨨ ᆠᨨ 盐ᆠ� �鼀�├ �矄 ᆠ  ᨨ鼀 ᆠ ᨨ  꾀 ᨨ � �  ᆠ  �矄 鼀� �   犨    ᆠᨨ 矄ᔼ  鼀� �鼀盐鼀 ᨨ��犨 � ᨨ   ᆠᨨ 矄矄矄� � ᨨ盐�   ᨨ �矄l犨 �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸 ᲼꾀 ҈桌

WWW.JEEBOOKS.IN

P-283

Dual Nature of Radiation and Matter �� 

쟼ᆠᨨ 矄

 

҈



㡰 l ᆠ矄矄犨� � ᆠ矄� f l 㡰 l�矄ᨨ �鼀泐  �  �矄 ᨨ盐 ᆠ㡰 ᨨ � ᨨ � �  ᆠ  >> f⏌㡰 l �矄 ᨨ �鼀泐  � �矄鼀  ᨨ盐�鼀矄 㡰 l� ᆠ矄矄 矄鼀矄l  ᨨl  ᆠ⏌f ᨨ ᨨᨨ㜠ᆠ�ᆠ ᆠ犨� � ᆠ�   ᨨᨨ 犨 � l   矄ᨨ� � ᨨ � �矄 V  ᔼ  � 泐   ᆠᨨᆠ ��ᨨ 矄㡰ᨨ V犨� l ҈⏌l ᲼꾀 ҈�桌 V

V

㡰

㡰 l

l

ᆠ㡰

V

㡰 V

҈⏌l 

҈⏌l

æ҈ö

� 犨  矄ᨨ� �ᨨ � V㡰  ç ÷ èlø �矄矄 ᨨ犨 �   ��盐 f҈  f   f 犨ᨨ├ 盐 ᆠ�ᨨ 矄 犨 �ᆠ ᨨ   ᨨᨨ犨� ��矄⏌ᆠᨨᆠ ᲼㜠�㝐҈桌  㝐҈ f҈

҈

f



㝐 f



҈ 鼀҈㡰 l

f҈  f  f = ҈     f҈  f  f =     ҈ hc ᆠ㡰  q µ e 㡰 盐�ᨨ�� ᆠ 盐矄 ᨨ鼀� ᨨᨨᆠᨨ 矄 ᨨ鼀鼀 鼀ᨨ 泐 ␔   ᨨᨨ 矄ᨨ  �泐�矄�├ 矄盐 ᆠᨨ 鼀 A ᆠ  ᨨᨨᆠᨨ 矄 鼀 �鼀盐鼀├� �ᆠ �泐 TA  ᨨ��犨 � lA 鼀 �鼀盐鼀├� �ᆠ  �泐ᨨ  ᨨᨨᆠᨨ 矄�  ᨨ鼀 ᨨ 鼀B泐  ᨨᨨ 矄ᨨ  �泐䰘�矄 TB = TA - ҈�㡰  ᔼ    ᨨ��犨 � ᨨ  矄 ᨨᨨᆠᨨ 矄�矄 l B = l A   

᲼҈黨黨㜠㝐├矄桌 㡰 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ A�矄� 㡰 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ B�矄 ᆠ㡰 TA㦨 㡰 TB㦨䰘� 㡰 㡰



㝐

 ␔  鼀ᨨ ᨨᆠ ᨨ鼀�ᆠᨨ� 矄ᨨ盐ᆠᨨ �� �矄 �矄 ᆠ ᨨ 鼀 ᨨ鼀 ᨨᨨᆠ�ᆠᆠ ᆠ盐ᨨ ᨨ�  矄盐�ᨨ ᆠ盐 矄ᆠ�泐 ҈鼀꾀 ᔼ    矄鼀 矄ᨨ盐ᆠ �矄 ᆠ   鼀 犨泐 ᨨ鼀    ᨨᨨᆠ�ᆠᆠ 

᲼҈黨黨㜠㝐├矄桌 㡰  矄ᨨ� �ᨨ �犨�ᨨ 㡰  矄ᨨ� �ᨨ �犨�ᨨ ᆠ㡰  矄盐�ᨨ ᆠ盐 犨�鼀꾀 㡰  矄盐�ᨨ ᆠ盐 犨�鼀꾀 � ᨨ � �  ᆠ� ᨨ 㜠泐盐�矄� ᆠ矄  꾀矄矄盐�  鼀�  ��ᨨ

᲼҈黨㜠㝐├矄桌 㡰  �  矄�泐� ᆠ矄矄 㡰  鼀� �鼀盐鼀犨 � � ᆠ矄矄 ᆠ㡰  �  矄�泐鼀� 盐 ᆠ  � 㡰  鼀� �鼀盐鼀犨 �  ᆠ矄矄   ᨨᨨᆠ�ᆠ ᆠ 矄盐ᨨ矄 ⼄盐 盐鼀 盐ᨨ ��  ᆠ盐矄 ᲼҈黨䰘㜠㝐├矄桌 㡰  �矄鼀� �鼀盐鼀 ⼄盐 ᆠ泐ᨨ �� ᨨ犨犨 �ᆠ  ᨨ  ᨨᨨᆠᨨ 矄鼀� 㡰   鼀 �鼀盐鼀 ├� �ᆠ  �泐ᨨ  ᨨᨨ ᆠᨨ 矄  矄ᨨ 泐ᨨ   ⼄盐 ᆠ泐ᨨ ��   ᨨᨨ

�矄�  矄�泐 ᆠ㡰  犨   鼀矄盐 ᆠ�矄 � 泐�盐鼀�     ᨨᨨᆠᨨ 矄 矄盐 ᆠ�鼀鼀 �泐 㡰 ᆠ�ᆠᆠ �ᨨ   ᨨᨨᆠᨨ 矄�矄⼄盐 �  䰘  矄 ᨨ 犨 �  ᨨ ᨨᨨᆠ�ᆠ鼀�矄矄�ᨨ  ᨨ鼀 鼀��矄�处 ᨨᨨᆠᨨ 矄犨�鼀� 犨 

 �矄鼀��矄�盐鼀�  犨� 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ ��ᨨ

ᨨ鼀 ᲼҈黨㜠㝐├矄桌 㡰 �犨�  鼀 㡰 ҈㜠犨� 㜠 鼀 ᆠ㡰 �犨盐�ᨨ鼀 㡰 ҈㜠犨盐�ᨨ鼀 9

Assertion and Reason Type Questions

 和T꾀TE㝐ENT㜠҈ ᲼䰘桌 ᔼ  ᆠᆠ� �ᨨ ��  㜠泐盐�矄� ᆠ矄   犨 � 矄ᨨ  ᆠ ᆠ�矄�ᆠ㜠泐矄 ᨨ ᨨᆠ  � 和T꾀TE㝐ENT㜠 ␔   ᆠᨨ 鼀矄�├矄 ��  㜠泐盐 ᨨ  ├� �ᆠ �泐�矄ᆠᨨ  � ᨨ㜠泐 �泐 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ 㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 盐錐和鼀 㜠 �矄졠 ᆠᨨᆠ  �ᨨ  ᨨ和鼀 㜠҈ ᆠ㡰 和鼀 㜠҈�矄 盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄 盐 10 Subjective Problems 黨 ᔼ  ᨨᨨᆠ�ᆠ �鼀 矄盐 ᨨᨨ 矄ᨨ  �泐�  矄ᨨ  ᆠ ᨨ  � �犨ᨨ├ 盐 ᆠ�ᨨ  㡰 ᔼ  矄盐�ᨨ ᆠ盐 �矄�A㦨mA ᨨ�  矄�泐҈�␔⏌鼀   ᨨ� 犨  ᨨ ᨨ � ᆠ盐  㡰꾀矄ᨨ 犨�  ᨨ�  矄�泐ᨨ � ᆠ�   ��ᨨ

맔҈�␔⏌鼀 ᲼㜠㝐├矄桌 䰘 ⼄盐 ᆠ泐 ᨨ    ᨨᨨ  鼀�  盐 ᨨ  矄��ᨨ  ᨨ ᆠᨨ ᨨ ᆠ� 鼀  ᨨ鼀LᨨK矄 �矄 ᨨ盐 ᨨ 맔҈҈ 矄� �㝐ᨨ矄泐矄犨 �  ᨨ鼀�ᆠ

盐鼀ᨨ  鼀 ��    泐 �矄ᆠᨨ 矄  R㦨҈҈맔҈䰘鼀҈ ᲼㜠㝐├矄桌 䰘҈ 犨ᨨ鼀�ᆠ矄A Bᆠ ᨨ �맔҈鼀 ᆠ ᨨᆠ ᨨ 矄�ᨨ ᨨ ҈ᆠ鼀B ᆠ�矄ᨨ矄��ᆠ �ᨨ 䰘맔҈҈C꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ 鼀ᨨ �� 犨�  ᨨᨨ 矄ᨨ  �泐�ᆠ 矄矄

WWW.JEEBOOKS.IN

EBD_8341 P-284

Physics

� �ᨨ At㦨矄ᨨ ҈҈ ᨨᨨ 矄 ᨨ � 矄⼄盐鼀矄ᆠᨨ 꾀矄矄盐鼀 ᨨ  ᨨᨨᆠᨨ

�矄鼀�  ᨨ 泐҈ � ᆠ�    ᨨᨨ 矄꾀矄ᨨ 矄矄盐鼀   鼀�  ᨨᨨᆠᨨ 矄ᆠᨨᆠ 泐B   犨ᨨ├ 盐 ᆠ�ᨨ ᨨ A鼀� 矄ᆠᨨ 矄   盐鼀�  ᲼㜠�㝐├矄桌 㡰   盐鼀ᨨ  ᨨᨨᆠᨨ 矄鼀� 盐ᨨt㦨҈矄 㡰  鼀� �盐 ᨨ  ᆠ�ᆠ � 犨  矄 A Bt㦨҈矄 ᆠ㡰  ├� �ᆠ �泐ᨨ  鼀ᨨ矄 ��ᆠ ᨨᨨᆠᨨ

鼀� t㦨҈矄犨  �ᆠ 矄B �ᆠ �鼀├ 泐  ᨨᨨᆠᨨ ᨨᆠ B

├e㦨�맔҈҈ᔴ⏌㜠鼀  ᨨᨨᆠᨨ 矄鼀� 犨   鼀 ��ᨨ �矄� ᆠ�   ᨨ 矄盐 ᆠᨨ 犨ᨨ├ 盐 ᆠ�ᨨ ҈黨 矄 ᨨᨨᆠᨨ 矄 矄矄 ᨨ盐� ��ᨨ ᆠᨨ � � �a㜠�ᆠ矄꾀鼀 �鼀盐鼀

䰘

 �泐ᆠᨨ ᆠᨨ鼀� 矄犨�  a�ᆠᨨ ᨨ鼀 졔�ᨨ 鼀�� �矄� � ᨨᨨ �  �矄ᨨᆠ矄矄졔�ᨨ 矄  盐矄 ᨨ鼀  �   � ᨨ盐   ᆠ� 矄 �     ��矄� ᨨ   ᨨᨨ 矄泐� ��  ᨨ �    �├泐 ᨨ  鼀�  盐� �       ᆠᨨ鼀� �ᨨ ᲼ ├ 㦨҈맔҈҈�矄桌 ᲼҈黨黨黨㜠�㝐├矄桌 䰘 꾀矄矄盐鼀      ᨨ�� 犨 矄矄ᨨᆠ�  犨�  

ᆠᨨ ᆠ  ᨨ鼀矄 � �犨犨  ᨨ鼀矄  � � ᨨ  �鼀 矄�ᨨ 泐犨�  ᨨ 矄ᆠ ᨨ  ᨨ鼀�ᆠ矄�矄ᔼ�矄 ᨨ盐  ᨨ 矄盐ᆠ 矄 � �犨 �矄 ᨨ鼀 �   �矄 ᆠ 犨  ᨨ鼀矄ᨨ  泐 �矄处꾀矄�鼀�矄 � �犨�矄��  ᨨ鼀 �  �矄 � ᆠ矄 ᨨ�处盐 ᨨ ᨨ 泐� 鼀 �盐ᨨ   �   �泐ᨨ  ᆠᨨ 矄� ᆠᨨ ᨨ矄   矄盐ᨨ   ᨨ犨 �ᆠ  矄 � �犨ᨨ  泐 ᲼҈黨黨䰘㜠�㝐├矄桌 矄ᆠ� ᨨᆠ  ᨨ鼀

Topic-3 : Miscellaneous (Mixed Concepts) Problems 2 Integer Value Answer 꾀ᨨᨨ �矄 �  ᨨ鼀泐 犨泐ᨨ犨 矄 盐ᆠ盐矄 犨� ᆠ �Q㦨҈e犨 e�矄 ᆠᨨ �ᆠᆠ � ᔼ鼀├矄ᆠᨨ矄矄ᨨᆠ ᨨ ҈ 鼀ᨨ  盐ᆠ盐矄   ᨨ��犨 �  � 盐 �矄ᨨ  鼀㡰ᨨ  ᨨᨨ �矄 矄�矄 ├ ᨨᨨ 鼀矄矄mp㦨 �⏌㡰´ ҈䰘├�錐h⏌e㦨 ҈ ´ ҈҈�矄⏌ᔴ錐 㦨黨맔҈黨鼀⏌ 錐҈ 鼀㦨҈҈�鼀᲼҈㜠ᔼ桌 pe

҈

6

MCQs with One or More than One Correct Answer

 �鼀 ᨨ �� 盐 矄矄盐 ᆠ鼀鼀  �鼀 ᆠ ᆠᨨ 矄�  矄ᆠ├ᨨ 泐鼀盐 �⧤鼀�� � ��ᨨ �├ᨨ� 矄ᨨ盐ᆠ犨  �犨 ᨨ鼀 꾀 ��  �� 盐�矄ᨨ矄  ᨨ鼀 �矄 ᆠ



ᨨ ҈鼀꾀矄矄盐鼀 盐�ᨨ  泐矄ᨨ  ᨨ矄ᨨ ᆠ�ᆠ盐犨�  �盐矄鼀鼀 

├和  㜠ᨨ 鼀

ᆠᨨ 矄 㦨�䰘맔҈␔鼀⧤ ␔� 矄 �矄ᆠ鼀 ᆠᨨ 矄 㦨黨맔҈鼀㜠⧤ ᆠ├矄 ᆠᨨ 矄 㦨맔҈矄矄 ᨨ �� � ᆠ盐盐鼀 㦨맔҈鼀矄҈㡰 㡰 ᨨ犨 � 泐  �鼀 �矄�   �␔ ᨨ�␔ 㡰  � ᨨ犨 � �� ᨨᨨ 泐ᨨ  ᨨ矄 �矄�   �҈�맔҈␔ᨨ�맔҈␔ ᆠ㡰   犨 �  ᆠᨨ矄ᨨ � � ᨨ   鼀 �鼀盐鼀 �  矄�泐ᨨ �� �矄҈҈ 鼀 㡰 ├� � �犨 � ᨨ 鼀�  ��ᨨ ᨨ ҈䰘 鼀 ᨨ 盐鼀ᨨ  ᨨᨨ 矄 � � 矄ᆠᨨ � ᨨᨨ 泐ᨨ  ᨨ矄 �矄�    � 䰘�맔҈҈҈ᨨ�맔҈҈҈

Answer Key Topic-1 : Matter Waves, Cathode and Positive Rays ҈ ҈҈

ᆠ㡰 ᆠ㡰

 㡰 ҈ 㡰

 㡰 ҈ 㡰

 㡰 ҈ 㡰

� ᆠ㡰 ҈� 㡰

 㡰 ҈ 㡰

䰘 ᆠ㡰 ҈䰘 ᆠ㡰

 㡰 ҈ 㡰

黨 ᆠ㡰

҈ 㡰

Topic-2 : Photon, Photoelectric Effect X-rays and Davisson-Germer Experiment ҈ ҈҈ ҈ ҈ ҈ �҈ �  ҈

㡰  ᆠ㡰 ҈ 㡰  㡰  㡰  处㡰 � 맔҈㡰  㡰 � 䰘㡰

㡰  㡰  㡰 � 㡰  㡰 䰘 㡰  ᆠ㡰 ҈ 㡰 ҈ 㡰 ҈� ᆠ㡰 ҈ ᆠ㡰 ҈䰘 㡰 ҈ 㡰  㡰  㡰 � 㡰  㡰 䰘 㡰  㡰  㡰  㡰 � 㡰  ᆠ㡰 䰘 㡰  ҈㡰  ҈㡰  䰘㡰 � �㡰  㡰 䰘 黨㡰  맔҈鼀⏌矄㡰 � 䰘处㡰 � ᆠ矄矄㡰 �� �䰘 矄 � 矄 �黨 ᆠ㡰  ᆠ㡰 ҈ ᆠ㡰  ᆠ 㡰  ᆠ㡰 䰘 ᆠ 㡰   㡰 Topic-3 : Miscellaneous (Mixed Concepts) Problems  ᆠ 㡰

㡰 黨 ᆠ㡰҈ ᨨ 盐矄㡰 ᆠ㡰 ҈黨 㡰  㡰 㡰 黨 㡰  㡰 㡰 黨 㡰  ᆠ㡰 ҈҈㡰 黨 㡰 � ҈㡰 ⼄盐 ᆠ泐㡰 ᆠ㡰  ᆠ㡰

WWW.JEEBOOKS.IN

P-285

Atoms

Atoms

26

Topic-1 : Atomic Structure and Rutherford's Nuclear Model 1 ҈

MCQs with One Correct Answer

� 犨 �ᆠ  �ᆠ矄 矄盐矄ᨨ  盐  ᨨ �ᨨ ᨨ� �鼀 犨� ᲼㝐�  ᔼ桌 a㜠�ᆠ矄�矄 q和ᆠ� � � Y盐鼀ᨨ 矄ᆠ a㜠�ᆠ矄 ᆠ ᨨ矄矄ᆠ 鼀�ᆠ  ᨨᨨ矄ᆠ㡰

㡰

ᆠ㡰



㡰



꾀  �ᆠᨨ  �泐�㝐�矄矄ᆠ  ᨨ盐� ҈ 泐 �  盐 �盐鼀 盐ᆠ盐矄  �矄 ᆠᨨ ᆠᨨ矄矄 ᨨᆠ �矄ᨨ  ᨨ ᨨ  ᲼㝐� ҈黨҈㜠㝐├矄桌 㡰 ҈处 㡰 ҈҈ᆠ鼀 ᆠ㡰 ҈҈ᆠ鼀 㡰 ҈҈�ᆠ鼀

Topic-2 : Bohr's Model and the Spectra of the Hydrogen Atom 1 ҈

MCQs with One Correct Answer

ᔼ  泐 ᨨ� ᨨ鼀 ᆠᨨ 鼀├矄 矄��ᨨ  ᨨ鼀 n졔҈㡰 ᨨ n ᔼ n>>҈  ⼄盐 ᆠ泐ᨨ  ��ᨨ 鼀� �矄ᨨᨨ�ᨨ ᨨ [㝐� Sep.02, 2020 (II)] ҈ ҈ ҈ ҈ 㡰  ᆠ㡰  㡰  n n n n

 �泐⼄盐� ᨨ�ᨨ �矄 泐 ᨨ� �├�ᨨ � �矄 �ᨨ盐 矄�矄黨 泐 �矄␔ �矄  犨 �  ᨨ   ��ᨨ 鼀� 犨   ᆠᨨ �  �矄�ᨨ 盐鼀矄 ᨨ鼀 矄ᆠᨨ  ᆠ� 矄ᨨ �ᨨ盐 矄䁸 ᲼㝐� 黨 ᔼᔼ桌 㡰  鼀 㡰 ҈҈ 鼀 ᆠ㡰 � 鼀 㡰  鼀

�鼀�ᨨ ᨨ ᨨ盐�ᨨ ᨨ ᆠᨨ � �矄�ᨨ盐 矄ᨨ��   泐 ᨨ�  ᨨ鼀�矄҈´ ҈҈ 矄 



㡰 



�

⼄盐 ᆠ泐ᨨ ᨨ盐�ᨨ ᨨ  ᆠᨨ � �矄 �矄 ᆠ� 矄 � s҈㡰�矄 ᲼㝐� 䰘 ᔼ桌 㡰 ҈´ ҈҈ 㡰 䰘´҈҈ ᆠ㡰 ´ ҈҈� 㡰 �´ ҈҈

ᆠᨨ �  泐 ᨨ� ᨨ鼀 �矄盐鼀矄 ᨨ鼀  �  ᆠ� 矄ᨨ 矄ᆠᨨ  ᆠ� 矄 矄盐矄⼄盐 泐 ᨨ   �矄  ᆠ�  矄  �ᨨ ᨨ    矄ᆠ� 犨 � 矄l҈⏌ lᨨ   ᨨᨨ 矄鼀� �  �矄ᨨᆠ矄矄 �矄 ᲼㝐� ҈꾀�҈黨ᔼᔼ桌 㡰 ⏌䰘 㡰 䰘⏌� ᆠ㡰 䰘⏌� 㡰 黨⏌䰘 ᔼ �졔졔ᆠᨨ �  �矄ᨨ ᨨ��矄 ᆠ� ᨨ泐  ��ᨨ ᨨ 犨 � l␔   �ᨨ �矄  ᆠ� ᨨ  �ᨨ盐 矄� ᨨ矄矄�犨泐矄 � ᆠ盐 � �� 鼀 � 鼀�矄矄�ᨨ 矄㡰ᨨᨨ 矄� 矄ᆠ� 矄ᨨ矄 ␔  �矄 盐ᨨ l䁸 ᲼㝐� ҈꾀�҈黨ᔼᔼ桌 ෌� h㦨맔҈矄錐c㦨맔҈鼀矄҈㡰 㡰 ҈҈ 鼀 㡰 黨 鼀 ᆠ㡰 ҈ 鼀 㡰 ҈ 鼀

WWW.JEEBOOKS.IN

EBD_8341 P-286

6.

7.

8.

9.

10.

Physics

Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as 660 nm, the wavelength of the 2nd Balmer line (n = 4 to n = 2) will be; [Main 9 April 2019 I] (a) 889.2 nm (b) 488.9 nm (c) 642.7 nm (d) 388.9 nm Radiation coming from transitions n = 2 to n = 1 of hydrogen atoms fall on He+ ions in n = 1 and n = 2 states. The possible transition of helium ions as they absorb energy from the radiation is : [Main 8 April 2019 I] (a) n = 2 ® n = 3 (b) n = 1 ® n = 4 (c) n = 2 ® n = 5 (d) n = 2 ® n = 4 A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength 980Å. The radius of the atom in the excited state, in terms of Bohr radius a0, will be: [Main 11 Jan 2019 I] (a) 25a0 (b) 9a0 (c) 16a0 (d) 4a0 In a hydrogen like atom, when an electron jumps from the M-shell to the L-shell, the wavelength of emitted radiation is l. If an electron jumps from N-shell to the Lshell, the wavelength of emitted radiation will be: [Main 11 Jan 2019 II] (a)

27 l 20

(b)

16 l 25

(c)

25 l 16

(d)

20 l 27

An electron from various excited states of hydrogen atom emit radiation to come to the ground state. Let ln, lg be the de Broglie wavelength of the electron in the nth state and the ground state respectively. Let Ln be the wavelength of the emitted photon in the transition from the nth state to the ground state. For large n, (A, B are constants)[Main 2018] B (a) L n » A+ 2 (b) Ln » A + Bln ln (c) L 2n » A + B l 2n

11.

12.

(d) L 2n » l

If the series limit frequency of the Lyman series is v1, then the series limit frequency of the P-fund series is : [Main 2018] (a) 25 nL (b) 16 nL (c) nL/16 (d) nL/25 The energy required to remove the electron from a singly ionized Helium atom is 2.2 times the energy required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is: [Main Online April 15, 2018] (a) 20 eV

13.

(b) 79 eV

(c) 109 eV

(d) 34 eV

Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths r = l1/l2, is given by [Main 2017]

(a) r =

3 4

(b) r =

1 3

(c) r =

4 3

(d) r =

2 3

14. According to Bohr’s theory, the time averaged magnetic field at the centre (i.e. nucleus) of a hydrogen atom due to the motion of electrons in the n th orbit is proportional to : (n = principal quantum number) [Main Online April 8, 2017] (a) n –4 (b) n –5 (c) n –3 (d) n –2 15. A hydrogen atom makes a transition from n = 2 to n = 1 and emits a photon. This photon strikes a doubly ionized lithium atom (z = 3) in excited state and completely removes the orbiting electron. The least quantum number for the excited state of the ion for the process is : [Main Online April 9, 2016] (a) 2 (b) 4 (c) 5 (d) 3 16. As an electron makes a transition from an excited state to the ground state of a hydrogen - like atom/ion : [Main 2015] (a) kinetic energy decreases, potential energy increases but total energy remains same (b) kinetic energy and total energy decrease but potential energy increases (c) its kinetic energy increases but potential energy and total energy decrease (d) kinetic energy, potential energy and total energy decrease 17. If one were to apply Bohr model to a particle of mass ‘m’ and charge ‘q’ moving in a plane under the influence of a magnetic field ‘B’, the energy of the charged particle in the nth level will be : [Main Online April 10, 2015]

æ hqB ö (a) n çè ÷ 2pm ø

æ hqB ö (b) n çè ÷ 8pm ø

hqB ö (c) n æç è 4pm ÷ø

æ hqB ö (d) n ç è pm ÷ø

18. The radiation corresponding to 3 ® 2 transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of 3 × 10–4 T. If the radius of the largest circular path followed by these electrons is 10.0 mm, the work function of the metal is close to: [Main 2014] (a) 1.8 eV (b) 1.1 eV (c) 0.8 eV (d) 1.6 eV

WWW.JEEBOOKS.IN

P-287

Atoms

҈黨

泐 ᨨ�  ҈҈㡰盐�盐鼀 ҈㡰矄� �泐�ᨨ �矄 �盐鼀

(





)

 +

  ᨨ盐泐�ᨨ �矄 � �盐鼀 (  �

)

 ++

 

ᨨ  ᆠᨨ  ᨨ盐    盐ᆠ盐矄 ᔴᨨ 矄�    ᆠᨨ

 矄��ᨨ  ᨨ鼀 㦨ᨨ 㦨҈ᔼ  犨 � 矄ᨨ 鼀�  ��ᨨ   l҈ l   l    l   矄ᆠ�泐  

ᨨ �鼀泐犨 �ᆠ ᨨ ᨨ   ᨨᨨ犨� ��矄ᆠᨨᆠ䁸 ᲼㝐� ҈桌 㡰 l҈ = l  = l  = l  㡰 l҈ = l  = l  = l  ᆠ㡰 l҈ = l  = l = 黨l 

҈



㡰 l҈ = l  = l = l

� � � �泐ᨨ  ᆠᨨ �  泐 ᨨ� ᨨ鼀�矄 ҈  �泐⼄盐� ᨨ鼀ᨨ ᆠᨨ  ᨨ鼀   �矄 ᆠ� 矄ᨨ �졔졔�矄 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 ҈ 㡰  ᆠ㡰 ҈ 㡰  ᔼ  泐 ᨨ� �├ᨨ鼀ᆠᨨ 鼀├ 矄��ᨨ  ᨨ鼀

 �泐 犨�  ⼄盐 盐鼀 盐鼀  ᨨ  ᨨ  犨� ⼄盐 盐鼀 盐鼀 ҈㡰ᔼ  >>҈  ⼄盐 ᆠ泐ᨨ  ��ᨨ

鼀� �矄ᨨᨨ�ᨨ ᨨ ᲼㝐� ҈桌 ҈ ҈ 㡰  㡰



҈ ҈ ᆠ㡰  㡰 



 ᔼ    ᨨ 矄鼀ᨨ  ᨨ  泐 ᨨ� 㜠�├ ᨨ鼀   ᨨᆠ 犨    盐ᆠ盐矄    ᆠᨨ �矄 鼀ᨨ � � 矄 e æ ҈ b ö F= ç + ÷  犨 b�矄ᆠᨨ 矄  ᨨ �矄ᨨ鼀 pe è r  r  ø   �盐矄ᨨ   n  ᨨ� �  鼀矄 ᨨ   ᨨ   �盐矄 æ e h ç a =  ç mp e  è

ö ÷ �矄 ÷ ø

᲼㝐� 졠 � 꾀�҈桌

㡰 rn㦨anb

㡰 rn㦨an졔b

ᆠ㡰 rn㦨anb

㡰 rn㦨an졔b

犨 � ᨨ   �矄矄ᆠ� �  鼀矄�矄 ᨨ  泐 ᨨ� ᨨ鼀�矄�҈꾀  犨 � ᨨ  矄ᆠᨨ 矄ᆠ� �  鼀矄�矄ᨨ 矄� �泐㜠�ᨨ �   �盐鼀 ᨨ鼀�矄 ᲼҈҈桌 㡰҈҈�꾀 㡰 ҈꾀 ᆠ㡰꾀 㡰 䰘꾀  �矄犨 �  �  盐�ᨨ��ᨨ ᨨ   泐 ᨨ� 矄ᆠ盐鼀�矄҈ 鼀 矄鼀矄犨 � �

 �  ��ᨨ ᨨ   泐 ᨨ� 矄ᆠ盐鼀 ᨨ  矄 � �㡰�矄 ᲼䰘桌 㡰  鼀 㡰  鼀 ᆠ㡰 ҈ 鼀 㡰 ҈ 鼀 � 꾀  ᨨᨨ  ᆠᨨ� 矄 犨�   矄�ᨨ 泐 泐 ᨨ�  ᨨ鼀 �

�ᨨ盐 矄� 矄�ᆠ泐쟼 �泐ᨨ  ᆠᨨ� � � ᨨᨨ

�矄҈꾀 �鼀� ᨨ  ᨨ ᨨ 鼀�ᆠᨨ矄ᆠᨨ 

 ᨨ   ᨨᨨ  ᆠᨨ� 矄 犨�  矄鼀 泐 ᨨ�  ᨨ鼀 � 矄�ᆠ泐犨�   �泐ᨨ ҈�␔ 犨�ᨨ矄 泐  ᆠᨨ䁸 ᲼�和桌 㡰 졠  ᨨᨨ ᨨ  �泐҈  ᆠᨨ ᨨ  �泐҈ 㡰  ᨨᨨ ᨨ  �泐ᨨ ҈ ᆠ㡰  ᨨᨨ ᨨ  �泐҈ 㡰 졠  ᨨᨨ ᨨ  �泐҈  ᨨ  ᨨᨨ ᨨ ҈  ᔼ  ᨨ鼀҈Fm�䰘 ᨨᨨ犨矄 ᨨ 鼀ᨨ    �盐矄 ᨨ ҈Fm�䰘�矄n�鼀矄 ᨨ  �盐矄   � n ᲼和桌 㡰 ҈ 㡰  ᆠ㡰  㡰 ҈⏌ 䰘 ᆠ�ᆠᨨ �犨 ᨨᨨ   ᆠᨨ �矄 r 犨 �矄ᆠᨨ 矄 꾀矄矄盐鼀� � r ᨨ 矄鼀ᨨ ᨨ�ᆠ犨���ᨨ ᨨ rn犨� n n� � � ᆠ�⼄盐 盐鼀 盐鼀䁸 ᲼和桌 㡰 rn µ n 㡰 rn µ ҈⏌n 㡰 rn µ ҈⏌n ᆠ㡰 rn µ n 졔졔  꾀泐 ᨨ� ᨨ鼀 � �ᨨ ᨨ �  矄ᆠᨨ

�� 泐V㦨Vln

 ᆠ� 矄ᔼ  l    l �  �矄ᆠ�ᆠᨨ �ᆠ  �盐鼀ᨨ鼀  E E� �矄ᆠ� ��矄  

᲼和桌 㡰

l  > l �  E>E�

㡰

l  㦨 l �  EE�

ᆠ㡰

l  㦨 l �  E>E�

㡰 l   l �  EE� 黨  矄��ᨨ  ᨨ鼀 矄n 㦨ᨨn 㦨�  泐 ᨨ� 㜠 �├ᨨ鼀矄盐矄� 盐�ᨨ ��ᨨ ᔼ   ��ᨨ

᲼҈和桌 犨�ᨨ�  �   矄��ᨨ

㡰 ®҈ 㡰 ® ᆠ㡰 ® 㡰 �®  ᆠᨨ �  泐 ᨨ� ᨨ鼀鼀├矄 矄��ᨨ  ᨨ鼀   ᆠ� 矄ᨨ �ᨨ盐 矄␔ �ᆠ ᨨ   ᨨᨨ犨� � 矄鼀 矄�矄盐䁸 ᲼和桌 㡰 ᔼ矄├� �ᆠ �泐� ᆠ矄矄 �矄ᨨ � ᨨ  ��矄 ᆠ矄矄 㡰 ᔼ矄 ├� �ᆠ  �泐 ᆠ矄矄 ᨨ �  �泐 � ᆠ矄矄 �矄ᨨ �泐鼀� 矄 矄鼀 ᆠ㡰 ᔼ矄├� �ᆠ ᨨ ��矄 ᆠ矄 �矄ᨨ �  �泐� ᆠ矄矄 㡰 ᔼ矄├� �ᆠᨨ � ᨨ ��矄 ᆠ矄 ҈ ᔼ鼀��  ᨨ鼀鼀 盐ᨨ ᨨᨨ   泐ᨨ �ᆠ �ᆠᨨ  ᨨ盐 鼀矄矄ᨨ  ᆠᨨ 盐 � �  矄鼀ᆠ �矄 ᆠᨨ 꾀泐 ᨨ ᨨ鼀鼀ᨨ   ᆠᨨ 矄� ᨨ矄矄� 矄��ᨨ 矄ᨨ  �矄 泐ᨨ �ᆠ �ᆠᨨ  �矄 ᆠ�  ᨨ �矄犨 �  ᨨᨨ  犨�鼀�  矄犨 �  l  �� �

鼀矄ᨨ   泐 �ᆠᨨ 矄 R ᨨ  泐 ᨨ� ᨨ鼀㡰 ⼄盐ᨨ ᲼和桌 㡰 黨⏌ �R㡰 㡰 ⏌ �R㡰 ᆠ㡰 ҈⏌ �R㡰 㡰 ⏌R

WWW.JEEBOOKS.IN

EBD_8341 P-288







Physics

ᔼ  泐 ᨨ� 矄ᆠ盐鼀 犨 � ᨨ a� �矄�

鼀犨 矄�  矄ᆠ盐鼀ᨨ  �矄 � 泐a�  犨 � �矄䰘 鼀쟼矄�鼀 矄 ᨨ  � 泐犨� 矄ᆠᨨ �矄 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 맔҈鼀⏌矄 㡰 맔҈䰘鼀⏌矄 ᆠ㡰 맔҈鼀⏌矄 㡰 맔҈�鼀⏌矄 꾀矄ᨨ 鼀ᨨ  鼀� �鼀盐鼀 �泐 � 㡰⼄盐� ᨨ 鼀ᨨ   ᆠᨨ  ᨨ鼀   �ᨨ盐  矄 ᨨ  ᨨ盐泐 �ᨨ �  �ᨨ鼀 Z 㦨㡰�矄 ᲼҈黨黨䰘㜠҈㝐├桌 㡰 ҈�҈ 㡰 ҈ ᆠ㡰  㡰 ҈ ᔴᨨ 矄�  矄ᆠ� 矄盐� � ᨨ鼀  矄��ᨨ

n =  ® n = ҈ �   ᨨ鼀矄 �ᨨ 矄�� ᨨ犨  矄 ᨨ矄犨 �  �矄ᨨ 盐ᆠ 泐 ᲼҈黨㜠҈㝐├桌 㡰 泐 ᨨ� ᨨ鼀 㡰 盐�盐鼀ᨨ鼀 ᆠ㡰 和� �泐�ᨨ �  �盐鼀 㡰 ᨨ盐泐�ᨨ �矄 � �盐鼀 2

�



Integer Value Answer

ᔴᨨ 矄�  泐 ᨨ� 㜠�├�ᨨ �  ᨨ鼀犨� ᨨ鼀�ᆠ 盐鼀 犨� 矄� �ᆠᨨ ᔼ  鼀�矄矄�ᨨ 矄ᆠ盐鼀ᨨ  �矄 ᨨ鼀  ᨨᨨ 鼀� �   㦨ᨨ 㦨҈ 矄��ᨨ

矄 �泐䰘 ��     ᨨᨨ 鼀� �  

㦨ᨨ 㦨 矄��ᨨ  �ᨨ � �ᨨ  �泐ᨨ   泐 ᨨ� ᨨ鼀�矄҈ 盐ᨨ Z�矄힘힘힘힘힘힘힘힘힘힘 ᲼꾀 ҈桌 꾀 ᆠᨨ �   泐 ᨨ� ᨨ鼀盐 �ᨨ矄 矄��ᨨ

ᨨ鼀 ᨨ�犨� ⼄盐 盐鼀 盐鼀 �ᨨ ᨨ 犨� ⼄盐 盐鼀 盐鼀 �  矄ᆠ�泐 � ��

� 㦨�     矄鼀矄ᨨ矄矄� �矄 ᲼꾀 ҈䰘桌 䰘 꾀 泐 ᨨ� ᨨ鼀� �矄�ᨨ盐 矄�矄� � 泐��  ᨨ 犨 � 黨䰘处 ├� � ᆠ⏌㦨҈䰘맔҈鼀  �ᨨ盐 矄 �泐ᨨ  泐 ᨨ� ᨨ鼀矄҈ 

盐鼀ᨨ � 矄矄 �  鼀�矄矄�ᨨ 矄ᆠ盐鼀�矄 ᲼꾀 ҈桌  꾀  ᆠᨨ  �矄    ᆠ�  矄 ᨨ �졔 �ᨨ  矄  �盐 鼀ᨨ鼀 盐鼀 ⏌p  ᨨ��犨 � ᨨ  ᆠᨨ

�  �矄矄�矄p  犨 �矄 ᨨ  �盐矄㡰  盐ᨨ p�矄  ᲼꾀 ҈�桌 黨 ᔴᨨ 矄�  泐 ᨨ� ᨨ鼀犨� �矄ᆠᨨ �  n ᨨ� 꾀 ᆠᨨ鼀� �ᆠ ��ᨨ ᨨ 犨 � 黨 鼀�矄盐矄 ᨨ �ᨨ �    ᨨ鼀 ᔼ    ├� �ᆠ  �泐ᨨ    ᆠ ᆠᨨ �矄҈   盐ᨨ n�矄 hc㦨҈nm㡰 ᲼꾀 ҈�桌

  � ᨨ � ��矄ᨨ  ᆠᨨ ᔼ 

3 

Numeric Answer

꾀�ᆠᨨ 鼀矄矄㝐⏌ᆠᆠᨨ� 矄犨�  泐 ᨨ�

ᨨ鼀矄和ᨨᨨ   ᆠᨨ�矄�ᨨ  �ᆠᆠᨨ鼀矄ᨨ 矄  ᨨ鼀ᆠᨨ�矄 �ᨨ矄ᨨ�矄 �矄 ᆠ� 矄 

� ��├� �ᆠ �泐ᨨ  �ᆠ � 㡰�矄    盐ᨨ �矄 ᲼㝐� 和� ᔼ㡰桌

෌�  鼀矄矄ᨨ   泐 ᨨ� ᨨ鼀ᨨ҈෌⏌ᆠ㡰 ҈ ᔼ  � 矄ᆠᨨ  泐 ᨨ� ᨨ鼀 �  ᆠ犨

 �矄    矄 ᨨ矄 犨 � 矄 ᨨ   泐鼀

矄�矄 �矄  处  ᆠᨨ矄ᨨ � � �  ᆠ ᨨ   矄ᆠ  矄�矄� 处�矄힘힘힘힘힘힘힘힘힘힘 [㝐� Sep.04, 2020 (I)]   �矄鼀鼀ᨨ  鼀矄�矄ᨨ  泐 ᨨ� ᨨ鼀 矄  犨 �  ᨨ  �҈ 处  犨 �  ᨨ    矄ᆠᨨ 鼀鼀ᨨ  鼀矄�矄 �  鼀㡰�矄힘힘힘힘힘힘 ᲼㝐�  ᔼᔼ桌 4

Fill in the Blanks

 ᔼ  ᨨ 鼀ᨨ ᨨ   泐 ᨨ� ᨨ鼀 �ᨨᨨ   ├� �ᆠ �泐ᨨ  ᨨ  �泐ᨨ    ᆠᨨ  �   ⼄盐 盐鼀矄n�矄 ᲼҈黨黨㜠҈㝐├桌  ᨨ  �盐矄ᨨ   �  ᆠᨨ ᨨ  ᨨ矄 ᨨᨨ盐矄ᨨ鼀 ᨨ鼀�ᆠ 盐鼀㦨҈�㡰ᆠ� �矄 ᨨ � 矄��ᆠᨨ  � �ᆠ�ᆠᆠᨨ 矄 㦨҈㡰�矄处᲼҈黨黨҈㜠҈㝐├桌 6

MCQs with One or More than One Correct Answer

� 꾀�ᆠᨨ 鼀矄矄m鼀ᨨ矄� ᆠ�ᆠ盐ᨨ�矄犨� ᨨ �  �泐V r㡰㦨Fr犨 F�矄ᨨ矄��ᆠᨨ 矄  r�矄�矄 �矄 ᆠ ᨨ鼀 ᨨ��� ᔼ矄 ��矄ᆠᆠ盐 盐矄� �   ᨨ  鼀ᨨ  ᔼ    �盐矄ᨨ   �ᆠ矄 ᨨ� �矄  ᨨ 泐R �矄矄   �泐  ᨨ 泐v  E矄ᆠ�泐    ᨨ  n ᨨ� h�矄   ᆠ├矄ᆠᨨ 矄 㡰 ᲼꾀 桌 㡰 R µ n҈⏌    v µ n  ⏌  㡰 R µ n  ⏌    v µ n҈⏌   æ n h F  ö ᆠ㡰 E = ç ÷  è p m ø

҈⏌ 

҈⏌ 

æ n  h F  ö  E = 㡰 ç ÷ è p  m ø  꾀  泐 ᨨ�  ᨨ鼀   矄ᨨ� �   ᨨᨨ  ᨨ 犨 � l�矄 ᆠ�  ᨨ鼀 矄n㦨҈ᨨ 矄 n 㦨ᔼ鼀鼀 �泐   ᆠᨨ 盐鼀矄ᨨn 㦨m 矄 泐 鼀�� �   ᨨᨨ  ᨨ  犨 �  l    ᆠ  �� 鼀ᨨ鼀 盐鼀ᨨ ᨨ鼀 盐ᨨ 矄ᨨ�ᨨ  ҈  鼀�矄矄�ᨨ Dpa Dpe矄ᆠ�泐ᔼ  l a ⏌ le =  � 犨 �ᆠ ᨨ  ᨨ�ᨨ 矄㡰�矄⏌ᆠᨨᆠ䁸 ᲼矄hc㦨҈ 鼀錐҈ 鼀㦨҈黨鼀h c ᆠ├矄 ᆠᨨ 矄  矄 ᨨ �� 矄ᆠ�泐桌᲼꾀 ҈黨桌 ҈ 㡰 Dpa ⏌ Dpe =  㡰 �ᨨᨨ ├� �ᆠ �泐ᨨ  ᆠᨨ �  矄 ҈ n㦨m ᨨ 矄n㦨҈�矄  ᆠ㡰 m㦨 㡰 l㦨҈ 鼀

WWW.JEEBOOKS.IN

P-289

Atoms

�� 泐 ᆠ� 矄矄 ᨨ 泐 ᨨ� �├ᨨ鼀矄 矄ᨨᆠ 泐 � 矄矄㡰 犨�  盐ᆠ ᆠ �    �   泐  �� ᆠ�⼄盐 盐鼀 盐鼀 犨  >>҈␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰盐䁸᲼꾀 ҈桌 㡰 � ᆠ  � �     �� ᨨ  犨ᨨ ᆠᨨ 矄ᆠ盐� ᨨ�矄 ᨨ矄 ᨨ  ᨨ  㡰 � ᆠ  � �     �� ᨨ  犨ᨨ ᆠᨨ 矄ᆠ盐� ᨨ�矄�矄矄҈⏌

ᆠ㡰 �ᆠ  � �    �泐ᨨ 犨ᨨᆠᨨ 矄ᆠ盐� ᨨ�矄�矄矄҈⏌  㡰 � ᆠ  ��     �盐 鼀ᨨ鼀  ᨨ  犨ᨨ ᆠᨨ 矄ᆠ盐�ᨨ�矄�矄矄҈⏌

  �盐矄ᨨ  ᨨ�ᨨ  ᆠᨨ � 泐 ᨨ� 㜠�├ ᨨ鼀�矄�犨 �矄 ᨨ  �盐矄ᔼ矄ᨨ� �盐 䰘

 ᔼ�矄��   �矄 ᆠ├ᆠᨨ 矄  p �矄 泐 �ᆠᨨ 矄  ᨨ矄矄�犨 � 矄㡰犨 

 ᨨ鼀 㜠 ᆠ�矄�矄 㡰 ᲼꾀 ҈桌

鼀ᨨ鼀 盐鼀�矄

㡰

黨 

㡰

ᔴ㡰 㝐ᨨ矄泐Ἐ矄 犨 㡰 泐 ᨨ� 矄ᆠ盐鼀 㡰 ᔴ  �ᨨ  ᨨᨨ  �泐 矄㡰 b㜠 ᆠ泐 � ᨨ├� �ᆠ �泐ᨨ ᆠᨨ 矄 8

矄矄�㜠҈

├泐 盐ᨨ ᨨ 矄 ᨨ泐ᨨ 矄ᆠ盐鼀ᨨ  泐 ᨨ� ᨨ鼀 �矄   ⼄盐 � �ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀 犨   

ᆠᨨ �矄ᨨ� �ᨨ盐 ᨨᨨ ␔犨�   �矄ᨨ �  ᨨ�ᨨ  鼀ᨨ�ᨨ  ᨨ �  ⼄盐 �   ᨨ�ᨨ   �泐ᨨ  �ᨨ鼀�ᆠ鼀ᨨᆠ盐矄矄盐鼀� ��ᨨ���  盐ᨨ � �矄ᨨ 矄⼄盐 � �ᨨ ᆠᨨ ��ᨨ  ᲼҈桌 � 꾀 �ᨨ鼀�ᆠ鼀ᨨᆠ盐 矄鼀ᨨ鼀 ᨨ � �I泐ᨨ 矄 ⼄盐 � �ᨨ ᆠᨨ ��ᨨ �矄ᨨ�ᨨ  �泐�     㦨�矄 ᨨᨨ犨 㡰�矄 㡰

҈ æ h ö ç ÷ n è p  I ø

ᆠ㡰

æ h ö nç  ÷ è p I ø

黨 ҈

黨  㡰 � 

 ᆠᨨ  �   泐 ᨨ�  ᨨ鼀 鼀├矄   矄��ᨨ

ᆠ㡰 黨

n҈ ® n  犨  n҈   n   � ᆠ� ⼄盐 盐鼀

盐鼀矄ᨨ  犨ᨨ矄矄꾀矄矄盐鼀 ᨨ 鼀ᨨ ᨨ �  �鼀�ᨨ ᨨ  ᆠᨨ �  � ��矄�矄 �� �鼀矄 �   � 矄 ᨨ矄矄�盐矄ᨨ n҈  n ᲼҈黨黨和㜠㝐├矄桌 㡰 n҈ =  n =  㡰 n҈ =  n =  �

ᆠ㡰 n҈ =  n = ҈ 㡰 n҈ =  n =  ᔼ ᨨ 矄鼀ᨨ ᨨ   泐 ᨨ� ᨨ鼀᲼҈黨㜠㝐├矄桌 㡰   �盐矄ᨨ    ᨨ��矄ᨨᨨ�ᨨ ᨨn 㡰   ᨨ  �泐 ᨨ    ᆠᨨ  �    ᨨ� �矄 � 矄泐ᨨᨨ�ᨨ ᨨn ᆠ㡰   �盐鼀ᨨ鼀 盐鼀ᨨ  ᆠᨨ �  ᨨ��矄 h  � �鼀盐�ᨨ  p 㡰  鼀� �盐 ᨨ ᨨ � �泐ᨨ  ᆠᨨ �

 泐ᨨ��矄�  �矄⧤쟼 7

�҈

Match the Following

和ᨨ鼀犨矄⏌ᨨᆠ矄矄矄�� �  ᔴᨨ盐鼀 ᔼ 㝐ᆠ  矄犨�   泐矄�ᆠ  ᨨ鼀 �� � ᔴᨨ盐鼀 ᔼᔼ   � �ᆠ 泐ᨨ盐  矄犨 泐 ├ � � ᨨ� 盐矄�  맔鼀� �� �  졠 和 ᲼䰘桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰  矄��ᨨ 犨 犨ᨨ 㡰 ᔴ ᆠ�矄�ᆠ㜠泐矄 ᨨ鼀�ᆠ �泐矄 㡰 쟼ᆠᨨ 鼀�矄矄�ᨨ  ᨨ鼀 ⼄㡰  ᨨᨨᆠ�ᆠ ᆠ 鼀�

Comprehension/Passage Based Questions

㡰

҈ æ h ö n çè p  I ÷ø



æ h ö n ç  ÷ è p I ø

� ᔼ�矄 ᨨ盐    ᆠ��ᨨ  ⼄盐 ᆠ泐 ᨨ鼀�ᨨ盐 ᨨ   �矄 ᆠ� 矄ᨨ ᨨ�ᨨ  ᨨ ᔴ졠鼀ᨨᆠ盐�矄  ´ ҈҈҈      鼀ᨨ鼀  ᨨ � � ᨨ ᔴ졠 p 鼀ᨨᆠ盐ᨨ盐�矄ᆠ ᨨ 鼀矄矄�矄ᆠᨨ矄ᨨ

ᆠᨨ矄ᨨ

├ = p ´ ҈   矄㡰 㡰

䰘 ´ ҈  ├� 鼀

㡰 ҈䰘 ´ ҈  ├� 鼀

ᆠ㡰 䰘 ´ ҈䰘 ├� 鼀 㡰 ҈҈䰘 ´ ҈ 䰘 ├� 鼀 � ᔼ ᔴ졠鼀ᨨᆠ盐  �矄 ᆠ犨 ᔴ 鼀矄矄㦨҈鼀盐㡰 �  졠 鼀矄矄㦨҈鼀盐㡰犨 ҈鼀盐 = ´ ҈ 䰘 ├� �矄  ᆠᨨ矄ᨨ

㡰

 ´ ҈ ҈ 鼀

㡰 ҈黨 ´ ҈ ҈ 鼀

ᆠ㡰

҈ ´ ҈ ҈ 鼀



 ´ ҈ ҈҈ 鼀

矄矄�㜠 ␔  �ᆠ�矄矄�ᆠ ᨨ鼀ᨨᨨ �x 㜠  �矄犨

x 㦨 x 㦨a, 犨 a �矄ᨨ   ᨨ鼀 �鼀 矄�ᨨ �矄 �泐 ᆠ ├ᨨ 泐ᆠ� 矄ᆠ� �ᆠ盐矄 ᨨ犨  ��矄ᨨ  �ᆠ鼀ᨨ� �� 矄盐ᆠ 矄�ᆠ ��ᨨ ᆠᨨ矄ᨨ ᨨ   ᨨ鼀�ᨨ ᨨ 矄 � �犨矄犨�  ᨨ 矄�矄 矄x =   x = a . 犨 � ᨨ  �矄矄 � �犨�矄 ᨨ  � 鼀ᨨ鼀 盐鼀p ᨨ  �ᆠᆠᆠᨨ � �ᨨ  ᨨ�� �ᨨ   �泐ᨨ  �ᆠᨨ 鼀矄矄m �矄 ᨨ�矄

p .  盐矄  �泐ᨨ  �ᆠ m ᆠ   ᨨ 泐⼄盐 盐鼀 盐鼀�n ├� �盐矄҈

� 鼀ᨨ鼀 盐鼀矄 E =

WWW.JEEBOOKS.IN

EBD_8341 P-290

㦨҈ᆠ  �ᨨ盐 矄㡰ᆠᨨ矄ᨨ � �ᨨ  盐鼀ᨨ ᨨᨨ矄�  矄 � �犨 矄 鼀ᨨ  矄ᆠ� ᨨᨨ 矄犨  ᨨᨨ犨� �  ⼄盐矄�ᨨ 矄 ᨨ�ᆠ鼀ᨨ� ��  � x = ᨨx = a. ├ h 㦨맔҈J s e㦨҈맔҈҈黨C �� ᨨ犨  �泐 ᨨ �ᆠ ᨨ�ᆠ盐盐ᨨ n �矄ᨨᨨ�ᨨ ᨨ ᲼黨桌 ᆠ㡰 a҈ 㡰 a 㡰 a 㡰 a⏌ � ᔼ  鼀矄矄ᨨ  �ᆠ�矄m = ҈맔҈├� a㦨

鼀  �泐ᨨ  �ᆠ� �矄�ᨨ盐 矄�矄ᆠᨨ矄矄 ᨨ ᲼黨桌 㡰 鼀 㡰 鼀 ᆠ㡰 鼀 㡰 鼀 �䰘 矄 ᨨ  �ᆠ ᆠ ├ �矄ᆠ盐矄�矄 ᨨᨨ�ᨨ ᨨ ᲼黨桌 㡰 n⏌ 㡰 n҈ ᆠ㡰 n҈⏌ 㡰 n 矄矄�㜠 ᔼ 鼀� 盐ᨨ 㜠졔�矄 졔�矄矄� �泐�ᨨ �  ᨨ鼀㡰 ᨨ鼀矄 졔�ᨨ 矄 ᆠ� ᨨ �矄ᆠ� �矄 ᆠ� 矄矄 和盐矄⼄盐 泐  ᨨ鼀矄  矄   � ᨨ  ᆠ��ᨨ

 �泐ᨨ졔�ᨨ 矄 泐ᆠᨨ�矄�ᨨ 矄㡰꾀矄矄盐鼀  ᨨ 鼀ᨨ  ᲼桌 ᨨ ᨨ鼀�矄 ᆠ泐�  � ⼄盐 盐鼀 盐鼀 ᨨ  矄 � 泐ᨨ盐 �

졔�ᨨ 矄�矄 㡰  㡰  ᆠ㡰  㡰 � �黨 犨 � ᨨ �� 鼀� �  �矄���ᨨ 泐 졔�ᨨ 矄 ᆠᨨ�矄�ᨨ 矄犨� ᨨ鼀矄�矄 㡰 �맔҈䰘鼀 㡰 �맔҈䰘鼀 䰘 ᆠ㡰 맔҈ 鼀 㡰 맔҈䰘鼀  �ᨨᨨ  ├� �ᆠ �泐ᨨ   㦨ᆠᨨ  ᨨ  ᨨ鼀ᨨ ᨨ 졔�ᨨ �矄 㡰 ҈⏌ 㡰 ҈⏌ ᆠ㡰 ҈ 㡰  10 Subjective Problems ҈

ᔼ  泐 ᨨ� 㜠�├ᨨ鼀 z㦨҈҈㡰  � ᨨ 泐鼀 矄�矄 矄犨 �  l  㜠ᨨ��Ἐ矄 犨 �  ᨨ ᆠᨨ �   ᨨ鼀犨 �ᆠ �ᨨ���  �矄矄ᨨl �  盐ᨨ n䁸 ᲼㜠㝐桌



 ᨨᨨ 矄 ᨨ鼀 鼀矄�矄� 泐 ᨨ� 矄ᆠ盐鼀 � �犨 � 犨 � 鼀ᨨ䰘 鼀� ᆠ�   ᨨ 鼀矄盐 ᆠᨨ 犨ᨨ├ 盐 ᆠ�ᨨ  �  鼀 �鼀盐鼀 ├� �ᆠ �泐ᨨ ᆠ ᆠᨨ  ෌� hc㦨҈ 鼀㡰 ᲼㜠㝐├矄桌 꾀 泐 ᨨ� 㜠�├ᨨ鼀 矄ᆠ� 泐 ᨨ 鼀ᨨ 㡰�矄 ᨨ矄 ᨨ鼀�矄� 犨 � 矄ᨨ��� � � ᨨ鼀 ᨨ矄矄�  矄��ᨨ 矄 犨   �ᨨ盐 ᨨ  矄 矄 矄   ��矄 犨  㜠�    㜠�  � ᆠ盐 � �ᨨ  矄盐矄㡰 ᲼㜠�㝐├矄桌 㡰 �  ᨨ鼀�ᆠ 盐鼀ᨨ  ᨨ鼀 㡰 ᔴᆠ盐 矄鼀矄犨 � 鼀� �  矄  矄��ᨨ 矄 ├hc㦨҈㜠 鼀�ᨨ盐 矄 �泐ᨨ  泐 ᨨ�

ᨨ鼀㦨҈㡰



Physics

 꾀 泐 ᨨ� 㜠�├ᨨ鼀ᨨ ᨨ鼀�ᆠ 盐鼀Z�矄�   ᆠ� 矄ᨨ ⼄盐 盐鼀 盐鼀nᔼᆠ 鼀�鼀 �鼀盐鼀 �泐  ᨨᨨ ᨨ ᔼ �鼀├矄 矄��ᨨ ᨨ⼄盐 盐鼀矄 n ᨨᨨ ᨨ  �泐�矄鼀�  � nZ   �ᨨ盐 矄 �泐 � 㡰 ᨨ �矄ᨨ鼀꾀矄ᨨᆠᆠ盐  鼀� �鼀盐鼀 �泐 � 㡰 ᆠ 鼀� 泐 �矄 ᨨ鼀 盐� � 㜠 ᆠ��ᨨ  ෌ᨨ盐  矄  �泐 ᨨ 泐 ᨨ� ᨨ鼀�矄҈ ᲼㜠㝐├矄桌 � 꾀 ᆠᨨ �  泐 ᨨ� 㜠�├ᨨ鼀�矄�   ᆠ� 矄 ᔼ 矄ᨨ �泐ᨨ ᔴᆠ盐 �㡰 ├� �ᆠ  �泐  ��㡰  ᨨ��犨 � ᨨ  ᆠᨨ  ᲼҈黨黨㜠㝐├矄桌  꾀 泐 ᨨ� �├ᨨ鼀 ᨨ鼀�ᆠ 盐鼀Z㡰�矄�  ��   ᆠ� 矄ᨨ ⼄盐 盐鼀 盐鼀n  ᆠ� ᨨ鼀ᆠ

鼀├ 矄��ᨨ ᨨ  �矄 ᆠ� 矄泐矄盐ᆠᆠ矄矄�泐 鼀�� � 犨ᨨ  ᨨᨨ 矄 ᨨ   �泐 ҈   ҈䰘  矄ᆠ�泐꾀 泐 ᨨ鼀 ᨨ鼀 矄鼀 ᆠ� 矄ᆠ 鼀├ 矄��ᨨ ᨨ 矄ᆠᨨ  ᆠ� 矄泐 矄盐ᆠᆠ矄矄�泐鼀�� �犨ᨨ ᨨᨨ 矄ᨨ  ��矄�   �黨�矄ᆠ�泐 ᲼҈黨黨㜠㝐├矄桌 鼀�  盐矄ᨨ n Z ᔼᨨ � �ᨨ  �泐ᨨ 㜠 ᨨ鼀㦨҈㡰 䰘 꾀�ᆠᨨ ᆠ �⼄盐ᨨ ᨨ  ᆠᨨ e 鼀矄矄�鼀矄 鼀矄矄ᨨ  ᆠᨨ  ᆠ  鼀盐㜠 鼀矄ᨨ 㡰 鼀ᨨ矄 �   ᆠ�ᆠ盐 ᨨ� ᨨ盐   盐ᆠ盐矄 ᨨ ᆠ �졔e ├ 鼀矄矄ᨨ   盐ᆠ盐矄ᨨ� � �㡰 꾀矄矄盐鼀� �  ᨨ 鼀ᨨ ᨨ  ᨨ鼀�矄�ᆠ ᨨ �矄矄泐矄鼀 ᲼҈黨㜠㝐├矄桌 �㡰 �  矄矄�ᨨ  ᨨ  �盐矄ᨨ    ᨨ  ᨨ� ��㡰 �  盐ᨨ n ᨨ犨 �ᆠ   �盐矄ᨨ  ᨨ��矄 ᨨ �鼀泐 矄鼀矄 ᨨ   �矄ᨨ ᨨ� ᨨ  泐 ᨨ� ᨨ鼀 ���㡰 �  犨 � ᨨ   ��ᨨ 鼀� 犨 

 鼀盐㜠鼀矄ᨨ 盐鼀矄 ᨨ鼀  � ᨨ�ᨨ   �矄 ᨨ�  꾀 ᨨ盐 �ᨨ �矄  � �盐鼀 ᨨ鼀 �矄 泐 ᨨ� 㜠�├犨� ᨨ鼀�ᆠ 盐鼀 ᲼҈黨�㜠㝐├矄桌 �㡰 �    犨 �  ᨨ     ��ᨨ  ⼄盐�  ᨨ  ᆠ� ᆠᨨ � �졔졔 ᨨ鼀  �矄ᨨ  � ᨨ ᨨ� ᔼᨨ �矄�ᨨ  �泐ᨨ   泐 ᨨ� ᨨ鼀 ⼄盐矄҈㡰 ��㡰 ᨨ犨 鼀 泐 矄ᆠ � 矄  ᨨ矄  �    鼀�矄矄�ᨨ 矄ᆠ盐鼀ᨨ  ᨨ ᆠ� 矄泐矄鼀䁸 黨 �ᨨ � �ᨨ  �泐ᨨ  泐 ᨨ� �├ᨨ ᨨ鼀�矄 泐 �矄 �㡰␔ �矄 犨 � ᨨ   ��ᨨ

鼀� 犨    ᆠᨨ 盐鼀矄 ᨨ鼀  �矄  ᆠ� 矄ᨨ �ᨨ盐 矄䁸 ��㡰␔ �矄  �盐矄ᨨ   �矄ᨨ� ᨨ �矄ᨨ鼀䁸 ᲼҈黨㜠㝐├矄桌 䰘 泐 ᨨ� ᨨ鼀� �矄�ᨨ盐 矄�矄 ᆠ� 泐鼀 矄ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ ��ᨨ ᨨ 犨 � 黨䰘�处ᨨ犨鼀 泐 �   � 矄 ᨨ矄矄� �    矄盐� � 矄ᆠ盐鼀 䁸 ᔴᆠ盐 ᨨ �矄犨 � 鼀ᨨ �矄 鼀Ӹᨨ盐鼀泐 矄矄盐鼀 �ᨨ � �ᨨ  �泐 ᨨ 泐 ᨨ� ᨨ鼀矄҈

WWW.JEEBOOKS.IN

P-291

Atoms

Topic-3 : Miscellaneous (Mixed Concepts) Problems 10 Subjective Problems ��  ᨨ鼀 �矄ᆠ �盐ᆠᨨ � � � 泐 ᨨ� ᨨ鼀矄 矄ᨨ  矄盐 ᆠᨨ �ᆠᨨ 矄ᨨ �盐鼀 ├� �ᆠ �泐 ᨨ   矄矄 ᨨᨨᆠᨨ 矄鼀�  ᨨ鼀矄ᨨ �盐鼀�矄䰘

犨ᨨ├ 盐 ᆠ�ᨨ  ᨨ矄ᨨ �盐鼀�矄҈ � ᲼҈黨黨㜠҈㝐├矄桌 㡰   �泐ᨨ   ᨨᨨ 矄ᆠ盐矄� �  ᨨᨨᆠ�ᆠ 鼀�矄矄�ᨨ  㡰  ⼄盐 盐鼀 盐鼀矄ᨨ  犨ᨨ矄� ᨨ �

 鼀�矄矄�ᨨ ᨨ  矄 ᨨᨨ 矄 ᆠ㡰  ᆠ  ��   �盐鼀ᨨ鼀 盐鼀ᨨ  ᆠᨨ

�   泐 ᨨ� ᨨ鼀�  ᨨ 矄��ᨨ  㡰  ᆠᨨ�矄 ᨨ  鼀�� �ᨨ鼀矄矄盐鼀� ��ᨨ 矄 ᨨ  矄��ᨨ  ᔼᨨ � �ᨨ ᨨ �ᨨ  泐 ᨨ� �矄҈㡰 쟼ᆠᨨ 矄�  泐 ᨨ� �├ᨨ鼀 Z㦨㡰鼀├ 矄��ᨨ 矄 ᨨ鼀  �  ᨨ  ᨨ盐 ᨨ�  ᨨ鼀  ᨨ盐 ᨨ   � ᨨ� 矄盐� � ��ᨨ 矄� ᆠ�   ᨨ鼀泐 ᨨ 鼀 ᆠ ᨨᨨᆠᨨ 矄 矄ᨨ� � ᨨ � ᨨ    ᨨᨨᆠᨨ 矄 ᆠ  泐  矄 ᨨ 犨 � �矄黨�ᨨ矄ᔴᆠ盐 犨ᨨ├ 盐 ᆠ�ᨨ ᨨ   鼀     矄ᨨ� � ᨨ � ᨨ    ᨨᨨᆠᨨ 矄ᆠ 泐 ᨨ �犨 � 

҈





泐 �ᆠᨨ 矄 㦨҈黨맔 ҈ 䰘 鼀 -҈ 㡰᲼҈黨黨㜠䰘㝐├矄桌 꾀�矄ᨨ �  �ᆠ 泐 ᨨ� 㜠�├ᨨ鼀矄 矄矄ᨨ鼀ᨨ鼀矄�

 ᨨ犨矄 �ᨨ盐 㡰 �泐A 矄ᨨ鼀ᨨ鼀矄�  �ᆠ盐盐  ᆠ� 㡰 �泐B   ᨨ



ᨨ鼀矄�   泐ᨨ   �泐 ᨨ鼀矄ᨨ  �矄 鼀├ 矄��ᨨ  ᨨ ��   �泐 泐矄ᨨ� � 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ�� ᨨ  ᨨᨨ  �泐䰘和盐矄⼄盐 泐   ᨨ鼀矄 鼀�  ��ᨨ  ᨨ ᨨ 泐矄�  �    ᨨᨨ

 ��矄和ᨨ鼀ᨨ  鼀�  ᨨᨨ 矄  �泐䰘 矄ᨨ鼀  �泐鼀ᨨ 矄ᨨ鼀 矄矄  䰘 ᲼҈黨黨㜠㝐├矄桌 �㡰 �  � ᆠ�⼄盐 盐鼀 盐鼀ᨨ  � ��泐  ᆠ� B ��㡰 �  �ᨨ � �ᨨ  �泐 ᨨ �矄ᨨ鼀矄 ���㡰 �  鼀 �鼀盐鼀  鼀� �鼀盐鼀 ��矄ᨨ   鼀�  ᨨᨨ 矄 꾀矄� �ᆠᨨ ᨨ�矄ᨨ盐 矄�ᨨ 泐 盐ᆠ盐矄ᨨ ᆠ �졔Ze␔ Z�矄ᆠᨨ 矄  e�矄 鼀� �盐  ᨨ  ᆠᨨ �ᆠᆠ �ᔼ⼄盐�矄䰘ᨨ ᆠ�  ᆠᨨ  ᨨ鼀 矄ᆠᨨ ᨨ ᨨ�ᨨ  � ᨨ ᨨ� � ᲼҈黨҈㜠҈㝐├矄桌 �㡰 盐ᨨ Z ��㡰  �泐⼄盐� ᨨ ᆠ� ᆠᨨ  ᨨ鼀   � ᨨ  ᨨ盐 ᨨ ᨨ� ���㡰  犨 �  ᨨ    ᆠᨨ鼀� �ᆠ  ��ᨨ

⼄盐� ᨨ鼀ᨨ ᆠᨨ  ᨨ鼀  �矄ᨨ  ᨨ�ᨨ� � �泐 �㡰 ├� �ᆠ �泐ᨨ � �泐   �盐 鼀ᨨ鼀 盐鼀ᨨ  ᆠᨨ �   �矄ᨨ ᨨ� 㡰  �盐矄ᨨ   �矄ᨨ ᨨ� �ᨨ � �ᨨ  �泐ᨨ  泐 ᨨ� ᨨ鼀㦨҈ᨨ   �盐矄㦨�맔҈҈҈鼀ᨨᆠ�泐ᨨ �� 㦨맔҈鼀⏌矄ᆠ  ᆠ├矄ᆠᨨ 矄 㦨맔҈ᨨ盐矄㜠矄ᆠ㡰

Answer Key Topic-1 : Atomic Structure and Rutherford's Nuclear Model ҈

ᆠ㡰

 ᆠ㡰 Topic-2 : Bohr's Model and the Spectra of the Hydrogen Atom

҈ ҈҈ ҈ ҈ ҈ � �䰘

㡰  㡰 ҈ 㡰  ᆠ㡰  ҈��҈㡰 ᆠ 㡰�҈ 㡰 �

㡰 㡰 ᆠ㡰 㡰

 㡰  㡰 � ҈ 㡰 ҈ 㡰 ҈�  㡰  㡰 �  㡰  㡰 �  㡰  ҈㡰  꾀®錐®⼄矄錐ᔴ®錐®⼄ ᆠ㡰 �黨 ᆠ㡰  㡰

㡰 㡰 㡰 㡰 ҈㡰

 ҈   � �

㡰 ᆠ㡰 㡰 �㡰 ᆠ㡰 㡰

䰘 ҈䰘 䰘 䰘  �

㡰 ᆠ㡰 㡰 㡰 ᆠ㡰 㡰

 ҈   䰘 �

ᆠ㡰 黨 㡰 ҈黨 㡰 黨 㡰 黨  㡰  ᆠ㡰 ��

㡰 ᆠ㡰 㡰 㡰 ᆠ㡰 㡰

҈    黨 �

㡰 㡰 㡰 �҈㡰  㡰 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-292

Physics

27

Nuclei

Topic-1 : Composition and Size of the Nuclei ҈

 

1 MCQs with One Correct Answer

  �盐矄 R ᨨ   盐ᆠ盐矄 ᨨ 鼀矄矄  盐鼀 A ᆠ   矄�鼀 泐  ᨨ鼀盐R㦨 ҈맔҈҈�㡰A҈⏌鼀ᔼ ᨨᨨ犨矄     鼀矄矄   矄�泐 ᨨ   盐ᆠ盐矄 �矄 ᨨ   ᨨ  ᨨ  M ᨨ @ M 盐 ; ҈䰘 ´ ҈ -䰘 ├�㡰 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 ҈├�鼀 㡰 ҈҈├�鼀 ᆠ㡰 ҈├�鼀 㡰 ҈҈䰘├�鼀

�ᨨᨨ  鼀矄矄  矄��矄ᨨ  盐ᆠ�ᨨ ᔴ ҈졠�矄 ᆠᨨ矄ᨨ ᲼㝐� 꾀�҈黨 ᔼᔼ㡰桌 㡰 ҈ 㡰 ҈ ᆠ㡰 � 㡰  꾀 盐 矄 泐 盐ᆠ盐矄矄├矄� ᨨ犨ᨨ 盐ᆠ� 犨 �ᆠ 鼀ᨨ犨泐犨� ᨨᆠ��矄�  �ᨨᨨ 䰘  �ᨨᨨ   ��ᨨ   盐ᆠ� 矄矄盐鼀 ᨨ矄 �ᆠ㡰�矄 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰 䰘 㡰  ᆠ㡰  㡰 黨

�

ᨨ盐 �盐鼀 盐ᆠ盐矄 ᨨ犨 ᨨ矄�矄鼀矄矄泐犨� ᨨ盐鼀䁸 ᲼和桌 㡰 m µ V 㡰 m µ ҈⏌V ᆠ㡰 m µ V 㡰 m µ V 졠  ᨨ  鼀� �盐  ᨨ   矄�泐ᨨ  盐 �盐鼀 盐ᆠ盐矄 �矄 ᲼҈黨黨黨和㜠㝐├矄桌 ᲼mp㦨҈䰘맔҈䰘├�桌 㡰 ҈├�⏌鼀 㡰 ҈҈䰘├�⏌鼀 ᆠ㡰 ҈҈├�⏌鼀 㡰 ҈҈҈├�⏌鼀



5 True / False

ᨨ ᨨ 鼀� �盐 ᨨ    矄�泐ᨨ  盐ᆠ鼀�矄 ҈├�鼀 ᲼҈黨黨㜠㝐├矄桌



6 䰘

MCQs with One or More than One Correct Answer

鼀矄矄 盐鼀ᨨ  盐ᆠ盐矄�矄 ᲼҈黨㜠㝐├矄桌 㡰 犨泐矄矄矄  �矄ᨨ鼀�ᆠ 盐鼀 㡰 犨泐矄鼀ᨨ  �矄ᨨ鼀�ᆠ 盐鼀 ᆠ㡰 矄ᨨ鼀�鼀矄⼄盐ᨨ�矄ᨨ鼀�ᆠ 盐鼀 㡰 矄ᨨ鼀�鼀矄 鼀ᨨ      矄ᨨ鼀�鼀矄 ⼄盐 ᨨ �矄 ᨨ鼀�ᆠ 盐鼀

Topic-2 : Mass-Energy Equivalence and Nuclear Reactions 1 ҈



 º  盐ᨨ ␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨᆠ矄矄�矄ᨨ犨 泐 鼀ᨨ鼀 盐鼀  �泐ᆠᨨ 矄�ᨨ 䁸 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 졔 ® 盐�盐鼀ᨨ鼀 ᆠᨨ ᨨ盐 ᨨ  盐ᆠ盐矄㡰

MCQs with One Correct Answer

Ӹᨨ盐��  鼀矄矄ᨨ  䰘 � 㦨䰘҈盐 㝐矄矄ᨨ    㦨盐  㝐矄矄ᨨ  ҈҈  㦨҈䰘黨盐 ␔    � ᨨ  䰘 �  �矄 ᆠᨨ   � ᨨ    泐 ᨨᨨ

ᆠ盐  �泐�  � ├␔ 㡰�矄 ᲼㝐矄矄ᨨ  盐ᆠᨨ 㦨҈෌⏌ᆠ桌 ᲼㝐� 和 ᔼ㡰桌 㡰 �맔҈� 㡰 맔҈ ᆠ㡰 맔҈� 㡰 ҈맔҈ ෌�  鼀矄矄矄ᨨ �ᨨ盐矄ᨨ鼀�ᆠ�ᆠ矄鼀㦨҈䰘盐 鼀 㦨҈䰘盐鼀㦨�盐 鼀v 㦨鼀 㦨҈҈盐犨   º ᨨᨨ  º  盐ᨨ  º ᆠᨨ  v º  � 盐� ᨨ

㡰 ® 졔졔졔 v ᆠ㡰 졔® 졔g 㡰 졔졔®g 

�  � � � �泐 盐ᆠᨨ  ᨨ ҈ � 和  㝐矄矄ᨨ ᨨᨨ mp㦨҈䰘鼀矄矄ᨨ  盐ᨨ mn㦨҈䰘 鼀矄矄ᨨ �  盐ᆠ盐矄m和 㦨҈҈黨黨҈黨黨 ├҈㦨黨҈㝐㡰 ᲼㝐� 和 ᔼᔼ㡰桌 㡰 䰘�㝐 㡰 黨㝐 ᆠ㡰 㝐 㡰 �㝐

WWW.JEEBOOKS.IN

P-293

Nuclei

�



䰘

ᔼ ᆠᨨ├�ᨨ 黨� 盐�矄 盐泐盐矄 盐�  泐矄

 �泐矄  �矄矄�ᨨ �矄㝐෌�    꾀ᨨ� ᨨ 盐鼀㦨맔҈├�ᨨ鼀ᨨ ҈ 㦨҈맔҈҈黨 ᨨ犨ᨨ盐盐ᨨ  ᆠᨨ�矄ᆠᨨ矄ᨨ [㝐� Sep.02, 2020 (I)] 㡰 �㝐␔ 㡰 㝐␔ ᆠ㡰 ҈�㝐␔ 㡰 �㝐␔ ᔴᨨ 矄�    盐ᆠ �矄矄�ᨨ

Ne®졔ᔴ҈ ෌�   � � � �泐⏌ 盐ᆠᨨ ᨨ  ᔴ҈矄ᆠ�泐㝐䰘䰘㝐 䰘㝐 �  � 泐 ᆠᨨᆠ 矄鼀  ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰  �泐ᨨ ҈㝐犨�矄盐� 㡰 㝐 �泐犨�矄 ᆠ㡰  �泐ᨨ 㝐犨�矄 㡰  �泐ᨨ ҈҈黨㝐 矄ᨨ矄盐� ᔼ鼀��  ᆠᨨᆠᨨ 矄�� 鼀矄矄� ᨨ �泐   �ᨨ矄ᨨ犨ᨨ ҈黨犨 鼀矄矄 ᨨ    盐 ᆠᨨ 矄盐鼀   ᨨ盐 �    ᆠᨨ 犨�   ᨨᆠ�泐ᨨ �� ᆠ�矄맔҈鼀⏌矄㡰 ᲼㝐� 졠 � 꾀�黨҈䰘桌 㡰 黨�鼀 㡰 �鼀 ᆠ㡰 맔҈�鼀 㡰 맔҈��鼀 ␔   �盐鼀�矄ᨨ鼀  犨�  盐ᨨ 矄�盐 �ᨨ矄 �矄矄�ᨨ   �矄矄�ᨨ ᆠ�ᨨ ᆠ 犨� 矄 +  n҈ ® � ҈҈ +  ⧤ 黨 +  x + 턼  �泐㡰 犨  �ᆠ矄 鼀 xᨨ 盐ᆠ   �泐턼 �矄矄 ␔ �矄  鼀ᨨ  �ᆠx䁸 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 ᆠᨨ

㡰 a㜠�ᆠ ᆠ㡰 盐ᨨ

㡰 盐� ᨨ ᔼ  ᨨ�ᨨ 矄�� ᨨ犨E  ᨨ 矄鼀矄矄 �泐 ᨨ  盐ᆠ盐矄 n 盐ᨨ  ᆠᨨᆠᨨ�ᨨ �矄 ᲼㝐� 䰘桌 æ  ö æ҈䰘 ö æ 黨䰘 ö U > Eç I + E ç Y ÷ +  E n 㡰 㡰 E ç è 黨 ÷ø è � ÷ø è 黨 ø æ  ö æ҈䰘 ö æ 黨䰘 ö 㡰 E ç U < Eç I + E ç Y ÷ +  E n 㡰 è 黨 ÷ø è � ÷ø è 黨 ø æ  ö æ҈ ö æ 黨 ö U÷ < Eç Ba ÷ + E ç Kr ÷ +  E n㡰 ᆠ㡰 E ç è 黨 ø è � ø è  ø æ  ö æ ҈ ö æ 黨 ö U = Eç Ba ÷ + E ç Kr ÷ +  E n㡰 㡰 E ç è 黨 ÷ø è � ø è  ø ᔼ 矄ᆠ ᆠᨨ   盐ᆠ�ᆠᨨ鼀泐� ᨨᨨ 泐�

盐ᆠ�  �泐矄 ᨨ 泐�  盐ᆠ��矄᲼㝐矄矄ᨨ  盐ᆠ盐矄�矄鼀盐 鼀矄矄ᨨ 졠 泐�  盐ᆠ盐矄�矄 ᲼�和桌 ҈�黨黨黨鼀盐桌 㡰 䰘㝐 㡰 �҈㝐 ᆠ㡰҈㝐 㡰黨㝐 � � � �泐 盐ᆠᨨ  矄鼀矄矄 盐鼀 ᆠ盐 ᨨ

盐ᆠ��矄矄 ᨨ犨 �   ��盐W, X, Y Z ᨨ盐 盐ᆠ� � �ᆠ ᨨ   ᆠ盐 ᨨᆠ矄矄  犨ᨨ盐 矄  �泐�矄 ᲼҈黨黨黨和㜠㝐├矄桌

黨 



黨

҈

�

Binding Energy/nucleon in Mev



Y 8.5 8.0 7.5

X W

5.0

Z 0

90 30 60 Mass number of nuclei

120

҈҈

㡰 W ® X + Z 㡰 Y ® Z ᆠ㡰 W ® Y 㡰 X ® Y + Z 矄 盐ᨨ 矄ᆠ 矄�泐矄ᨨ犨  ᨨ犨 泐 㡰  盐矄ᨨ  矄 � � � ᲼҈黨黨㜠҈㝐├桌 㡰 矄矄� � 鼀 ᨨ盐� 犨 ᆠ㡰 矄�ᆠᆠᨨ�矄�ᨨ 矄犨�  泐 盐ᆠ� 㡰 泐� �矄ᨨ �ᆠ�ᆠ �  4

Fill in the Blanks

҈ ᔴᨨ 矄�   ᨨᨨ犨� �ᆠ�ᨨ     ҈  + ҈  =  + 턼 㝐矄矄ᨨ   盐�盐鼀ᨨ鼀㦨҈҈u 㝐矄矄ᨨ  �盐鼀ᨨ鼀㦨u

�矄�矄 盐ᆠᆠ�ᨨ � 犨 �ᆠ   �泐Q 矄 �矄㝐 ᲼҈黨黨㜠㝐├矄桌 ҈ ᔼ    盐ᆠ ᨨᆠ矄矄  ᔴ҈҈ ¾¾ ® � ҈҈ + b + +    矄 矄 ᨨ ᲼҈黨黨㜠҈㝐├桌 ҈ � � � ��矄 盐ᆠᨨ  ᨨ 盐ᨨ  ҈㡰 �盐鼀 㡰҈҈㝐 䰘㝐矄ᆠ�泐   �泐矄 犨  犨ᨨ 盐ᨨ 矄 盐矄ᨨ ᨨ鼀 �盐鼀

盐ᆠ盐矄 㡰�矄 ᲼҈黨㜠㝐├矄桌 6 MCQs with One or More than One Correct Answer ҈� 꾀矄矄盐鼀   盐ᆠ� � � �泐 盐ᆠᨨ  ⏌꾀㡰 矄盐矄鼀矄矄 盐鼀 꾀㡰�矄矄矄 ᨨ犨 �   ��盐矄 �矄 ᨨᨨᆠ ᨨᨨ矄 ᆠᨨᆠᆠ ᨨ�ᆠ 矄㡰�� ᨨ犨 ᲼桌 ⏌꾀     

҈





㡰 盐矄�ᨨ ᨨ 犨ᨨ 盐ᆠ�犨� 鼀矄矄 盐鼀矄泐� ��    �ᨨ ҈꾀�犨�矄 �泐 㡰 盐矄�ᨨ ᨨ 犨ᨨ 盐ᆠ�犨� 鼀矄矄 盐鼀矄泐� ��    �ᨨ �҈꾀҈犨�矄 �泐 ᆠ㡰 �矄矄�ᨨ ᨨ  盐ᆠ盐矄泐� ��  鼀矄矄 �ᨨ ҈꾀 犨�矄 �泐犨  ᨨ├ � ᨨ犨ᨨ⼄盐 �鼀 矄 㡰 �矄矄�ᨨ ᨨ  盐ᆠ盐矄泐� ��  鼀矄矄 �ᨨ 꾀 犨�矄 �泐犨  ᨨ├ � ᨨ犨ᨨ⼄盐 �鼀 矄 ҈ mp 鼀矄矄ᨨ ᨨᨨ mn 鼀矄矄ᨨ  盐ᨨ M҈   鼀矄矄ᨨ  ҈   盐ᆠ盐矄 M 鼀矄矄ᨨ    ᔴ

盐ᆠ盐矄 

᲼҈黨黨和㜠㝐├矄桌 㡰 M  =  M ҈ 㡰 M  >  M҈ ᆠ㡰 M  <  M҈ 㡰 M҈ < ҈ mn + m p 㡰 ҈䰘 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀  矄㡰�矄 㡰ᆠᨨᆠ䁸 ᲼҈黨黨㜠㝐├矄桌 㡰 矄鼀矄矄ᨨ 矄 盐ᆠ盐矄�矄矄矄   矄盐鼀 ᨨ  矄鼀矄矄矄ᨨ �矄矄  盐ᆠᨨ 矄 㡰 矄鼀矄矄ᨨ 矄 盐ᆠ盐矄�矄�    矄盐鼀ᨨ  矄鼀矄矄矄ᨨ �矄矄  盐ᆠᨨ 矄 ᆠ㡰 ᔼ  盐ᆠ �矄矄�ᨨ  �泐�矄矄 泐 盐矄� �犨ᨨ

盐ᆠ�ᨨ 鼀 �盐鼀鼀矄矄 ᨨ �鼀泐҈鼀盐㡰 㡰 ᔼ  盐ᆠ �矄矄�ᨨ  �泐�矄矄 泐 �鼀 �ᨨ

ᨨ 泐 泐 盐ᆠ盐矄

WWW.JEEBOOKS.IN

EBD_8341 P-294

҈

҈黨

Physics

盐� � 盐ᆠ 盐矄�ᨨ ᆠ�ᨨ

᲼҈黨䰘㜠㝐├矄桌 㡰  泐 盐ᆠ盐矄├矄� ᨨ犨ᨨ �鼀 矄泐�矄 㡰 ��  盐ᆠ盐矄ᨨ鼀  泐 鼀 盐ᨨ 矄├矄盐 ᆠ㡰  泐 盐ᆠ盐矄 ᨨ鼀   泐  鼀 盐ᨨ 矄 ├矄盐 㡰 犨ᨨ��  盐ᆠ�ᆠᨨ鼀� ᨨ�� � 盐ᆠ盐矄  ᨨ矄矄�泐ᨨ  ᨨ 盐ᆠ矄 ᨨ鼀  ᨨᨨ犨� �⼄盐�ᨨ 矄�ᆠ├ᨨ盐 ᨨ矄矄� 盐ᆠ 盐矄�ᨨ  ᆠ�ᨨ 矄 ᲼҈黨㜠㝐├矄桌 㡰  ᔴ҈ + ҈҈ ®  ᔴ҈ + 㝐 㡰  ᔴ҈ + ҈҈ ® 䰘 ҈ +  㝐 ᆠ㡰 㡰

҈ ҈ ҈� 䰘  + ҈ ®  졠 + 䰘㝐 � ҈ +  n ® � ҈ +  和 黨 黨 

10 Subjective Problems  ᔼ  盐ᆠᆠ�ᨨ �盐 �ᨨ矄 �矄矄�ᨨ �� � 㝐ᨨ  �泐 ᆠᨨ 矄҈奠 �ᆠ� ᆠ泐 ᨨ 盐ᆠ矄 ҈㝐␔ᨨ犨ᔼ  ᆠᨨ�矄ᨨ 盐 ᆠ�ᨨ  ᨨ҈泐矄 �  ᨨ鼀矄矄ᨨ 盐 �盐鼀⼄盐�  ᲼҈㜠�㝐├矄桌 ҈ ᔼ�矄ᨨᨨ矄 ᨨ盐矄  盐ᆠ 盐矄�ᨨ ᆠ�ᨨ

  ҈  +҈

᲼҈黨黨㜠㝐├矄桌  ®   �  盐ᆠᆠᨨᨨ 㝐␔� �ᔼ   �泐 ᨨ鼀  ᨨᆠ�ᨨ �矄盐矄 犨� �ᆠ  �ᆠ� ᆠ泐�

 ᆠᨨ ᨨ犨鼀 泐�鼀矄ᨨ  盐�盐鼀 盐犨�    泐 鼀矄矄矄ᨨ  ҈      ҈҈ᨨ鼀�ᆠ 鼀矄矄盐 �矄 ᨨ鼀�ᆠ鼀矄矄盐 �矄矄ᆠ�泐㡰

+  n҈

+  n҈ + g + 㝐

Topic-3 : Radioactivity 1 ҈

MCQs with One Correct Answer

꾀ᆠ���矄ᨨ   �ᨨᆠ�矄盐矄 ᆠ矄꾀 ᔴ 矄  泐 ᆠ盐矄꾀 ᔴ�   ��盐 



 �  㜠�矄 ҈ 꾀㡰  ҈ 㡰  ҈ ᔴ㡰 �  �ᨨ 





[Main Sep. 05, 2020 (I)] ᔼ   

䰘

  





꾀 ᔴ



 泐矄㡰 㡰 ҈҈ 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈ 꾀 �ᨨᆠ� 盐ᆠ盐矄 ᆠ泐矄泐犨ᨨ �  ᨨᆠ矄矄矄

  �  ᨨ  �矄ᨨᆠ矄矄�矄҈矄   ᨨ  矄ᆠᨨ �矄҈矄  ᆠ�  � ᨨ   盐ᆠ盐矄�矄 ᆠᨨ矄ᨨ ᲼㝐� 和� ᔼᔼ㡰桌 㡰 黨矄ᆠ 㡰 矄ᆠ ᆠ㡰 ��矄ᆠ 㡰 ҈矄ᆠ ᔼ    �ᨨᆠ� 鼀� ᆠ�ᨨ  ᨨ  ᆠ� 鼀� 鼀� � �   �鼀 t �矄 黨⏌҈    ᆠ�ᨨ   犨矄 鼀� � � t⏌�矄 [Main Sep. 03, 2020 (I)] �

҈

  䰘  㡰 ᆠ㡰 㡰 � �  

ᆠ��泐ᨨ  �ᨨᆠ�矄鼀 矄 ᨨ鼀䰘矄҈ᨨ� 矄҈� 鼀� 盐矄ᔼ矄  � �矄ᆠᨨ矄ᨨ᲼䰘 ᔼᔼ桌 㡰 䰘鼀� 㡰 鼀� ᆠ㡰 鼀� 㡰 �鼀�

犨ᨨ  �ᨨᆠ� 矄盐矄 ᆠ矄 꾀     ᆠ泐 ᆠᨨ 矄 矄�l l矄ᆠ�泐꾀t㦨矄鼀 矄  矄鼀 盐鼀ᨨ  犨ᨨ 盐ᆠ� �鼀├  ᨨ 

㡰



�



æ ҈ö �ᨨᨨ   盐鼀ᨨ  盐ᆠ�ᨨᆠᨨ鼀 ç ÷ 犨� è eø ᲼㝐� ҈꾀�҈黨ᔼᔼ桌



㡰 1/2l 㡰 ҈⏌l ᆠ㡰 ҈⏌l 㡰 ⏌l ᔼ  �ᨨᆠ� ᆠ泐ᆠ �  � �� 盐ᆠ盐矄�矄  黨  꾀   a㜠�ᆠ矄 b㜠�ᆠ矄犨 �ᆠ 鼀� ᔼ    盐ᆠ盐矄�矄 꾀   꾀 �� 泐 ᲼㝐� ҈ ҈黨ᔼᔼ桌 㡰 꾀㦨錐㦨 㡰 꾀㦨錐㦨 ᆠ㡰 꾀㦨錐㦨 㡰 꾀㦨錐㦨҈ 矄� � 盐ᆠᆠᨨ盐  ᆠᨨ盐 ᨨ 鼀� �ᆠ矄 ᨨ鼀 �ᨨᆠ�矄ᨨ盐ᆠ�矄鼀矄盐 꾀㦨�犨矄҈ ᆠᨨ盐 矄矄ᆠᨨ  㦨矄ᆠᨨ 矄�犨矄҈ᆠᨨ盐 矄 矄ᆠᨨ  ᆠᨨ盐  ᨨ矄  矄ᆠᨨ盐 矄 矄ᆠᨨ    㦨  矄ᆠᨨ 矄 �矄 ᆠᨨ矄 ᨨ ᲼㝐� ҈ ҈黨ᔼ桌 㡰  㡰 ҈� ᆠ㡰  㡰  꾀 �� � 矄  矄泐㦨 犨ᨨ �ᨨᆠ�矄盐矄 ᆠ矄꾀

 ᨨ  �ᆠ���矄 꾀  �鼀�矄  ᆠ泐矄犨� �鼀矄ᔼ    㜠� ᨨ 꾀�矄l    㜠� ᨨ �矄 ᲼㝐� 黨 ҈黨ᔼᔼ桌

  ⼄盐ᆠ���矄 �ᨨ

l  l  ᆠ㡰 㡰 l    ᔴᨨ � �ᆠ��泐 黨 꾀矄ᨨ盐�ᨨ ᆠᨨ � � �ᆠ�ᆠᨨ䰘 ᨨ Ҙᔴ�  ᆠ泐ᆠᨨ 矄 l�矄� ᆠ �   �鼀Ἐ矄 ᨨ 泐ᔼ ҈ᆠ鼀ᨨ ᨨᨨ �矄 犨  ᨨ鼀  �鼀Ἐ矄ᨨ 泐  ҈ 矄ᨨ � ᆠ�ᨨ  ᆠ��泐 ᨨ盐 犨矄 ᆠ泐矄 鼀� 盐␔ �矄 ᨨ盐鼀ᨨ ᨨᨨ  �矄 ᨨ犨� ��

 ᨨ 泐䁸 ҈ᔴ�㦨䰘맔҈҈ ᆠ泐矄ᆠᨨ   㦨҈ 矄l㦨㡰 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰 �矄 㡰 䰘�矄 ᆠ㡰 �矄 㡰 ��矄 ҈ 꾀 �ᨨᆠ� 盐ᆠ盐矄꾀犨�   �   ᆠ泐矄� ᨨ

盐ᆠ盐矄꾀㦨 �矄 ᨨ 盐ᆠ盐矄꾀矄ᨨ鼀�鼀  �ᨨᨨ   盐鼀ᨨ ᨨ ᨨ 꾀�矄  �矄��

泐 ᲼㝐� ҈䰘桌 㡰 l 

㡰

WWW.JEEBOOKS.IN

P-295

Nuclei

T 㡰 t = ᨨ� ҈㡰 ᨨ�  ᨨ�҈ 㡰 t = ᆠ㡰 t = T ᨨ�҈ ᨨ�   㜠�矄 ᨨ 犨ᨨ �ᨨᆠ�鼀 矄꾀    鼀� 盐矄 鼀� 盐矄矄ᆠ�泐ᔼ ��泐 矄鼀矄 ⼄盐 盐鼀ᨨ  盐ᆠ�꾀 鼀� 盐矄 �ᨨᨨ ᆠ泐  盐鼀ᨨ 꾀  盐ᆠ�犨�᲼㝐� ҈桌 㡰 ҈ 㡰 � ᆠ㡰 ҈҈ 㡰 ҈ b  盐鼀ᨨ  b�ᆠ矄鼀� 泐҈�鼀 ᨨ  �ᨨᆠ� 盐ᆠ�  � 㦨҈� 矄㡰� 䰘� ᨨ盐矄 b �矄ᆠᨨ矄ᨨ 꾀ᨨ� ᨨ 盐鼀㦨맔҈⏌�鼀ᨨ㡰 ᲼㝐� 졠 � 꾀�҈҈҈�桌 㡰 맔҈҈ 㡰 䰘�맔҈҈  ᆠ㡰 ҈�맔҈ 㡰 ҈䰘�맔҈ 꾀�ᆠᨨ 犨ᨨᨨ  ᨨ鼀ᆠ 泐ᆠ盐矄 ᨨ犨矄 ᆠ泐矄  鼀� 盐 꾀 犨ᨨᨨ   �ᆠ ᨨ  矄鼀 矄�  ᆠ  �   鼀盐矄盐鼀 ᨨ�   ᨨ鼀ᆠ盐鼀 泐泐矄ᆠ├㡰矄 ᨨ犨矄  ᆠ泐矄鼀� 盐ᔼ   � ᨨ ᔴ҈�矄�䰘泐矄 

� ᨨ    犨ᨨᨨ   �ᆠ ᆠ  �    鼀盐矄盐鼀 �矄 ᨨ �鼀泐 ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰 ҈黨泐矄 㡰 ҈黨泐矄 ᆠ㡰 ҈黨黨泐矄 㡰 黨黨泐矄 꾀 �ᨨᆠ� 盐ᆠ�犨�  ᆠ泐ᆠᨨ 矄 �⏌矄�矄� � ᨨ 盐ᆠ ᆠᨨ 矄 ᨨ ҈ 盐ᆠ�⏌矄ᔼ 㦨  犨 ᨨ 盐ᆠ� �鼀犨   � 盐ᆠ��矄 ᲼㝐� 졠 � 꾀�҈҈҈桌

㡰 t = T ᨨ� ҈㡰

҈҈

҈

҈

҈

 㡰 l æç ö÷ 矄 è ø æ ö 㡰 l ç ÷ 矄 è ø

㡰 ҈矄 ᆠ㡰 l 矄 ҈�

҈

҈䰘

҈ 䰘  �矄 �ᨨᆠ�矄盐矄 ᆠ � �  � ᨨ  泐矄

�  ᨨ��泐  盐ᆠ盐矄盐 �ᨨ矄 ᆠ泐  犨ᨨ  �矄 ᲼㜠㝐҈桌 ҈ 

ᆠ㡰

 



A

X z + g ¾¾ ® X Z -҈ + a + b 

㡰

A

X z + ҈nᨨ ¾¾ ®

ᆠ㡰

A



A

A- 



҈ 

᲼和桌

X Z - + c

A

X z ¾¾ ® XZ + f A

X z + e-҈ ¾¾ ® X Z -҈ + g ҈�

  㜠� ᨨ  꾀�矄҈ m s �鼀├  ᨨ   �ᨨᆠ��泐ᨨ 矄鼀ᨨ ҈�꾀ᨨ ᆠ泐ᨨ҈⏌҈ ᨨ �矄 � ��盐�矄 ᲼和桌 㡰  m s 㡰  m s ᆠ㡰  m s 㡰  m s 꾀  �ᨨᆠ� 矄鼀 ᆠᨨ 矄�矄矄 ᨨ  犨ᨨ �矄� ᆠ 矄ᆠ�矄 � �⼄盐 盐鼀ᨨ ᨨ鼀矄� ��泐 鼀 � �鼀 ᨨ ᨨ 矄ᆠ�矄�矄t  ᨨ  ᨨ �矄�t  ᆠ泐 ᨨ 盐ᆠ矄� ᨨ ᆠ矄矄矄꾀ᨨ�矄鼀 ᨨ   ᨨ 盐鼀ᨨ  �ᨨᆠ� 盐ᆠ�矄 盐 ᆠ�ᨨ ᨨ �鼀 ␔ �ᆠ ᨨ   ᨨᨨ犨� � ��盐矄矄矄   ᨨ鼀ᨨ  �矄ᨨ䁸 ᲼҈和桌 

㡰

盐ᨨ 犨�᲼෌� l ҈㦨桌 ᲼꾀 ҈黨桌 㡰 黨 㡰  ᆠ㡰 ҈҈� 㡰  꾀 �ᨨᆠ�矄鼀和҈ � � ᆠ��泐�Ҙᔴ� 矄犨�ᆠ   盐鼀ᨨ  盐ᆠ�矄 ᨨ 矄鼀和犨 �ᆠ  矄

ᆠ��泐ᨨ ҈Ҙᔴ�   �矄ᨨ 和҈ 和ᆠ ᲼桌 㡰 泐矄 �泐矄矄ᆠ�泐 㡰 泐矄 ҈泐矄矄ᆠ�泐 ᆠ㡰 ҈泐矄ᆠ 㡰 �泐矄ᆠ

㡰

҈

A

㡰



 ᔼ   �ᨨᆠ�矄鼀 ҈黨 K  盐ᆠ� �  ᆠ泐� ᨨ  矄  Ca  盐ᆠ�犨�  ᆠ泐ᆠᨨ 矄 �맔҈҈  泐ᨨ� ᨨ矄 ҈ Ar  盐ᆠ�犨�  ᆠ泐ᆠᨨ 矄 �맔 ҈҈泐෌�  �  �矄矄鼀 矄   Ca     ҈  盐ᆠ�ᨨ 盐ᆠ 泐   盐ᆠ�ᨨ 泐  Ar ҈黨 K  ᔼ �鼀맔҈黨泐矄�  �ᨨᨨ  矄盐鼀ᨨ 矄  Ca      Ca  盐ᆠ�ᨨ  �ᨨᆠ� ҈黨 K  盐ᆠ��矄黨黨 

㡰 ҈

҈ 꾀 泐矄ᨨ  �ᨨᆠ�矄盐矄 ᆠ矄 ᨨ犨矄 ᆠ��泐 ᨨ  矄҈ 泐矄�矄ᆠ��泐ᆠᨨ鼀矄 矄 ␔ 犨矄�矄� ��ᆠ��泐䁸 ᲼和桌 㡰  矄 㡰  矄 㡰 ҈ 矄 㡰  矄 ҈黨 꾀 盐ᆠ盐矄犨� 鼀矄矄 盐鼀� ��泐矄鼀�矄

a 㜠�ᆠ ᔼ  Q 盐 ᨨ    ᆠ�ᨨ  �矄 �� 㝐 ᆠᆠ盐 ├� �ᆠ �泐ᨨ   a 㜠�ᆠ ᲼和桌 㡰 㝐 㡰 �㝐 ᆠ㡰 �㝐 㡰 �㝐  ␔ �ᆠ ᨨ   ᨨᨨ犨� �ᨨᆠ矄矄矄矄 矄 g 㜠 ᆠ泐䁸

㡰 t





t



t





ᆠ㡰

㡰 t



 ᆠᨨ 鼀� �  ��ᨨ ᨨ��� 矄 ᨨ鼀 㡰 �

ᨨ�矄ᨨ ᨨ鼀矄 ᲼҈和桌 㡰 ᆠᨨ 矄 �矄� ��  盐ᆠ� ᆠ㡰 ᆠ泐ᨨ  盐ᨨ �  盐ᆠ盐矄 㡰  ᨨᨨ 矄ᆠ� � ᨨ鼀  盐ᆠ盐矄  犨ᨨ �ᨨᆠ�鼀�矄X҈ X  ᆠ泐ᆠᨨ 矄 矄 ҈l   l 矄ᆠ�泐ᔼ � ��泐 泐  矄鼀

盐鼀ᨨ  盐ᆠ�   �ᨨᨨ   盐鼀ᨨ  盐ᆠ�ᨨ X҈ᨨ ᨨ X犨�҈⏌e �鼀 ᲼和桌 ҈ ҈ ҈҈ ҈ 㡰 ᆠ㡰 㡰 㡰 ҈l ҈҈l ҈l 黨l � ␔ �ᆠ ᨨ   ᨨᨨ犨� ��矄ᆠᨨᆠ矄鼀 䁸 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 泐矄矄鼀矄ᆠ ᨨ 泐矄 㡰 ෌鼀鼀泐矄 ��  �泐 盐ᨨ 矄 ᆠ㡰 꾀 �ᆠ矄矄� �泐�ᨨ �矄  �盐鼀ᨨ鼀矄 㡰 ᨨᨨ 矄  盐ᨨ 矄  ᆠ泐 矄鼀鼀矄矄

WWW.JEEBOOKS.IN

EBD_8341 P-296

26.

27.

28.

Physics

A radioactive material decays by simultaneous emission of two particles with respective half-lives 1620 and 810 years. The time, in years, after which one-fourth of the [1995S] material remains is (a) 1080 (b) 2430 (c) 3240 (d) 4860 Consider a particles, b particles and g - rays, each having an energy of 0.5 MeV. In increasing order of penetrating powers, the radiations are: [1994 - 1 Mark] (a) a, b, g (b) a, g , b (c) b, g, a (d) g, b, a The equation

35. To determine the half life of a radioactive element, a student dN (t ) dN (t ) is the rate versus t. Here dt dt of radioactive decay at time t. If the number of radioactive nuclei of this element decreases by a factor of p after 4.16 years, the value of p is [2010]

plots a graph of ln

4 11 H + ¾¾ ® 42 He 2 + + 2e – + 26 MeV represents [1983 - 1 Mark]

29.

30.

(a) b -decay (b) g-decay (c) fusion (d) fission Beta rays emitted by a radioactive material are (a) electromagnetic radiations [1983 - 1 Mark] (b) the electrons orbiting around the nucleus (c) charged particles emitted by the nucleus (d) neutral particles The half life of radioactive Radon is 3.8 days. The time at 1 th of the radon sample will remain the end of which 20 undecayed is (given log10 e = 0.4343 ) [1981- 2 Marks] (a) 3.8 days (b) 16.5 days(c) 33 days (d) 76 days. Integer Value Answer is an isotope of Iodine that B decays to an isotope of Xenon with a half-life of 8 days. A small amount of a serum labelled with 131I is injected into the blood of a person. The activity of the amount of 131I injected was 2.4 × 105 Becquerel (Bq). It is known that the injected serum will get distributed uniformly in the blood stream in less than half an hour. After 11.5 hours, 2.5 ml of blood is drawn from person's body, and gives an activity of 115 Bq. The total volume of blood in the person¡¦s body, in liters is approximately (you may use ex » 1 + x for |x| < < 1 and ln2 » 0.7). [Adv. 2017] For a radioactive material, its activity A and rate of change dN dA and R = – of its activity R are defined as A = , dt dt where N(t) is the number of nuclei at time t. Two radioactive sources P (mean life t) and Q (mean life 2t) have the same activity at t = 0. Their rates of change of activities at t = 2t R n are RP and RQ, respectively. If P = , then the value of RQ e n is [Adv.2015] A freshly prepared sample of a radioisotope of half-life 1386 s has activity 103 disintegrations per second. Given that ln2 = 0.693, the fraction of the initial number of nuclei (expressed in nearest integer percentage) that will decay in the first 80 s after preparation of the sample is [Adv. 2013-I] The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is 109 s. The mass of an atom of this radioisotope is 10–25 kg. The mass (in mg) of the radioactive sample is [2011] 2

31.

32.

33.

34.

131I

4

Fill in the Blanks

( )

36. When Boron nucleus 105 B is bombarded by neutrons, a -particles are emitted. The resulting nucleus is of the element ........ and has the mass number ...... [1986 - 2 Marks] 37. In the Uranium radioactive series the initial nucleus is

238

92

U

206

and the final nucleus is 82 Pb . When the Uranium nucleus decays to lead, the number of a-particles emitted is ......and the number of b-particles emitted is ..... [1985 - 2 Marks] 38. The radioactive decay rate of a radioactive element is found to be 103 disintegration/second at a certain time. If the half life of the element is one second , the decay rate after one second is _______ and after three seconds is _______. [1983 - 2 Marks] 6

MCQs with One or More than One Correct Answer

39. In a radioactive decay chain,

232 90Th nucleus

decays to

212 82 Pb nucleus. Let Na and Nb be the number of a and b particles, respectively, emitted in this decay process.

Which of the following statements is (are) true? [Adv. 2018] (a) Na = 5 (b) Na = 6 (c) Nb = 2 (d) Nb = 4 40. The half-life period of a radioactive element X is same as the mean-life time of another radioactive element Y. Initially both of them have the same number of atoms. Then [1999S - 3 Marks] (a) X and Y have the same decay rate initially (b) X and Y decay at the same rate always (c) Y will decay at a faster rate than X (d) X will decay at a faster rate than Y 41. The half-life of 131I is 8 days. Given a sample of 131I at time t = 0, we can assert that [1998S - 2 Marks] (a) no nucleus will decay before t = 4 days (b) no nucleus will decay before t = 8 days (c) all nuclei will decay before t = 16 days (d) a given nucleus may decay at any time after t = 0

WWW.JEEBOOKS.IN

P-297

Nuclei







 ᆠ泐ᆠᨨ 矄  ᨨ   �ᨨᆠ�矄鼀 �矄 l    㜠�  鼀 㜠� ᨨ  矄鼀矄ᆠ�泐��

泐 ᲼҈黨黨㜠㝐├矄桌 㡰 ҈⏌ l   ln㡰⏌ l 㡰 ln㡰⏌ l  ҈⏌ l ᆠ㡰 l  ln㡰 ҈⏌ l 㡰 l ⏌ ln㡰 ҈⏌ l 꾀 矄 泐  �ᨨᆠ�矄ᨨ盐ᆠᨨ   �  鼀�矄  ��ᨨ ᨨ �  矄�泐犨 �ᆠ �矄�鼀矄 鼀�矄矄�矄   鼀� �鼀盐鼀�鼀 犨 �ᆠ �犨ᨨ盐 ᨨ矄矄�ᨨ 犨ᨨ├矄 泐犨�  �矄矄ᨨ盐ᆠ�矄 ᲼҈黨㜠㝐├矄桌 㡰   㡰 ҈  ᆠ㡰   㡰 ҈  盐� � �� ᆠ泐 ᲼҈黨䰘㜠㝐├矄桌 㡰  ᨨ鼀�ᆠᆠᨨ �矄ᆠ 㡰  ᆠᨨ 犨 �ᆠ �矄 泐矄 犨� �   盐ᆠ盐矄 �矄ᆠ ᆠ㡰  盐ᨨ �   盐ᆠ盐矄 ᆠ泐矄鼀�� � ᆠᨨ

㡰   ᨨ    � � �  �泐 ᨨ    盐ᆠ盐矄 �矄 ᆠᨨ  � ᨨ ᆠᨨ

7

�

Match the Following

㝐ᆠ   盐ᆠᨨᆠ矄矄矄�� � ᆠᨨ盐鼀 ᔼ犨�   ᨨ�ᨨ�ᨨ 矄㡰� ᆠᨨ盐鼀 ᔼᔼ ᲼꾀 ҈�桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰 盐ᆠ 盐矄�ᨨ

㡰 꾀矄ᨨ�ᨨ ᨨ  鼀 㡰 �矄矄�ᨨ �  盐ᆠ ᆠᨨ ᔴ㡰 b㜠 ᆠ泐



㡰 쟼 �泐ᨨ 盐ᆠ�ᨨ � 矄矄 � 泐 ᨨ�  ᆠᨨ 矄�ᨨ

ᨨ �盐鼀 㡰 g㜠泐鼀�矄矄�ᨨ

矄㡰 泐犨 㡰 盐� ᨨ鼀�矄矄�ᨨ

㝐ᆠ �矄ᔼᨨ   盐ᆠᨨᆠ矄矄矄犨� �矄ᔼᔼᆠᨨ � � �   盐ᆠ盐矄 ᨨ ᨨ   ᨨ 盐ᆠ矄ᨨ ᆠ ᨨᆠ矄矄    矄ᆠ ᆠᨨᆠ 矄犨盐矄� � ᆠᨨ 矄��

ᨨ犨 �矄矄 ᲼꾀 ҈㜠ᔼᔼ桌 �矄ᔼ �矄ᔼᔼ 

䰘

⼄㡰

�

盐ᨨ 矄泐 黨   ᔴᨨ 盐ᆠ盐矄 䰘

꾀  ᆠ泐

҈

턼 b졔 ᆠ泐



 �矄矄�ᨨ



҈� ҈�  졠 ® 䰘 졠 +  ҈  黨  ® 黨 +  ҈� ҈  � ®   +  黨 ҈ 黨 盐 ® �䰘  + 

和 ᨨᨨ 鼀�矄矄�ᨨ

 ᔴᨨ 矄  턼 和 㡰   ҈  㡰 ҈    ᆠ㡰  ҈   㡰    ҈ ෌� ᨨ犨ᆠ� 鼀ᆠ � �泐⼄盐矄�ᨨ 矄犨  犨ᨨᆠᨨ盐鼀 矄 ᆠ  � ��鼀矄㡰�� ᔼ鼀鼀 �泐   ᆠᨨ盐鼀 矄 鼀ᆠ � ��� �矄�� 犨 ᆠ �鼀 ᨨ ᔴᨨ盐鼀  ᔼ 矄 ᨨ鼀ᆠ   犨�   �鼀矄 ᨨ ᔴᨨ盐鼀 ᔼᔼ泐 ᆠ�ᆠ� � ᆠᨨᆠ鼀ᆠ 矄㡰ᨨ   �鼀ᨨ ᆠᨨ盐鼀 ᔼᆠ 鼀ᆠ 犨� 鼀ᨨ  ᨨ �鼀ᨨ ᆠᨨ盐鼀 ᔼᔼ꾀 �鼀矄ᨨ ᆠᨨ盐鼀 ᔼᔼ鼀盐矄鼀ᆠ   㝐ᆠ   ᨨᨨ犨� � ᲼㜠㝐桌

ᔴᨨ盐鼀 ᔼ 꾀㡰 盐ᆠ 盐矄�ᨨ

㡰 盐ᆠ �矄矄�ᨨ

ᔴ㡰 b㜠 ᆠ泐 㡰 쟼 ᨨ 鼀�ᆠ 盐ᆠ ᆠ�ᨨ

8

ᔴᨨ盐鼀 ᔼᔼ 㡰 ᔴᨨ 矄矄ᨨ鼀鼀� ᨨ  �泐 ⼄㡰 ෌ 泐ᨨ矄矄� ᨨ

盐ᆠ�犨� ᨨ犨ᨨ鼀�ᆠ

盐鼀 㡰 ෌ 泐ᨨ矄矄� ᨨ

盐ᆠ�犨�  �� ᨨ鼀�ᆠ

盐鼀 矄㡰 쟼矄矄 �泐ᨨᆠ 矄泐 犨├ 盐ᆠ ᨨᆠ矄

Comprehension/Passage Based Questions

矄矄�㜠҈

鼀矄矄ᨨ  盐ᆠ盐矄 꾀   �矄矄矄   矄盐鼀ᨨ  鼀矄矄矄ᨨ 꾀㜠㡰 盐鼀ᨨ  盐ᨨ 矄  盐鼀ᨨ ᨨᨨ 矄�   盐ᆠ盐矄

 �泐⼄盐� ᨨ ᆠᨨ矄ᨨ � �鼀矄矄 �  ᆠ�矄 ├ ᨨ犨 矄 � � � �泐ᨨ   盐ᆠ盐矄꾀 泐 盐ᆠ盐矄 ᨨ 鼀矄矄㝐ᆠ ├� ᨨ犨ᨨ��  盐ᆠ�ᨨ 鼀矄矄矄鼀҈ 鼀 ᨨ 泐�  鼀҈졔鼀㡰㝐꾀矄ᨨ犨ᨨ��  盐ᆠ�ᨨ 鼀矄矄矄鼀 鼀 ᆠ 盐 �ᨨᆠᨨ鼀 盐矄�ᨨ   ᨨ鼀 泐 盐ᆠ盐矄ᨨ 鼀矄矄 㝐Ἐᨨ 泐�  鼀졔鼀㡰>㝐Ἐ 鼀矄矄矄ᨨ 矄ᨨ鼀 盐ᨨ鼀矄 �� �  ᨨ犨 ҈ ҈

҈䰘�盐

 ҈

҈҈盐

 ҈

҈�盐

  

盐

  �

҈�҈盐

䰘  �

䰘҈盐

䰘  

黨黨��盐

  和

҈黨҈䰘黨盐

҈�  ෌

҈�҈黨҈黨盐

  

�黨䰘��盐

黨  �

黨盐

҈  ᨨ

黨黨䰘盐

҈盐㦨黨㝐⏌ᆠ㡰 ᲼꾀 ҈桌  ├� �ᆠ �泐 � ├㡰ᨨ   �ᆠ犨    ҈

盐ᆠ盐矄  ᨨ 矄盐 �ᨨ矄  ᆠ泐�矄 㡰 �҈黨 㡰 � ᆠ㡰 �䰘䰘 㡰 �҈ 黨 ᆠᨨᆠ矄鼀 �矄

㡰  盐ᆠ盐矄  � ᆠ 鼀�  �ᆠ ҈ 㡰  盐ᆠ盐矄  ᨨ ᆠ 鼀�ᨨᨨ

ᆠ㡰 盐ᨨ   �ᆠᆠ 盐 �ᨨᆠᨨ鼀 盐矄�ᨨ

 㡰  盐ᆠ� 䰘      和 ᆠ 盐 �ᨨᆠᨨ鼀 盐矄�ᨨ

10 Subjective Problems � 꾀  �ᨨᆠ� 矄鼀 ᨨ   ᆠ泐矄 ᨨ   ᨨ盐�   ᨨᆠ矄矄 ᨨ犨 �ᆠ    㜠� �矄�맔҈黨泐矄 �   �ᨨᨨ  盐鼀 ᨨ  盐ᆠ� ᨨ   ᨨ   �鼀 ᨨ ҈�맔҈黨泐矄෌�  㡰҈⏌㦨҈ ᲼㜠㝐├矄桌 �҈ 꾀 �ᨨᆠ�矄鼀鼀�矄nb㜠�ᆠ矄� 矄ᆠᔼ    矄ᆠ�鼀�矄䰘�nb㜠�ᆠ犨 �矄 鼀 � ᨨ   矄鼀䁸 ᲼㜠㝐├矄桌

WWW.JEEBOOKS.IN

EBD_8341 P-298

�

�

�

Physics

꾀  �ᨨᆠ� 盐ᆠ盐矄 X ᆠ泐矄 ᨨ 盐ᆠ盐矄 Y 犨�  ᆠ泐ᆠᨨ 矄 lx㦨҈矄㜠҈Y 盐  ᆠ泐矄ᨨ矄

盐ᆠ盐矄Z犨�  ᆠ泐ᆠᨨ 矄 lY㦨҈⏌矄㜠҈ᔼ ��泐  ᨨ 泐X 盐ᆠ�  � 盐鼀�矄Nᨨ㦨҈和 盐 ⼄盐�ᨨ 矄 ᨨ ᨨ盐�ᨨ 矄ᨨ XY Z

ᨨ盐�ᨨ ᨨ Y 盐ᆠ盐矄矄 盐 ᆠ�ᨨ ᨨ �鼀�矄��

泐NY t㡰㦨 NᨨlX⏌ lX㜠lY㡰㡰{  㜠lYt㡰㜠  㜠lxt㡰晤 �   �鼀  犨 �ᆠ  NY �矄 鼀 �鼀盐鼀   鼀�    ᨨ盐�ᨨ 矄X Z � 矄  ᲼҈㜠�㝐├矄桌 盐ᆠ�ᨨ  �ᨨᆠ�鼀 A� �ᨨ 盐ᆠ  ᆠᨨ 矄 a 鼀  矄 ᆠ泐ᆠᨨ 矄 l꾀�鼀 t㦨 N 盐ᆠ�ᨨ  鼀  ᲼҈黨黨㜠㝐├矄桌 㡰 ᔴᆠ盐  盐鼀Nᨨ  盐ᆠ�ᨨ A�鼀t 㡰 ᔼ a㦨Nlᆠᆠ盐  盐鼀ᨨ  盐ᆠ�ᨨ A  ᨨ   㜠� ᨨ A 矄ᨨ �鼀�� �盐ᨨ N矄 t ®¥ 꾀�� � 矄  �奠盐 ᆠ泐  �ᨨ㜠ᆠ�

盐ᆠ� �   矄鼀 꾀  ҈ 矄ᆠᨨ 矄   盐鼀 ᨨ 盐 ᆠ泐  盐ᆠ� 盐ᆠ矄ᨨ҈�奠ᔴᆠ盐 �㡰鼀 㜠 � ᨨ   盐ᆠ�  ��㡰 �鼀� 犨 �ᆠ   盐鼀ᨨ 盐 ᆠ泐  盐ᆠ� 犨� 盐   盐ᆠ ᨨ �奠 ᨨ     盐ᆠ  盐鼀 ᲼҈黨黨㜠㝐├矄桌

�� 꾀矄鼀⼄盐 �泐ᨨ 矄ᨨ盐�ᨨ ᆠᨨ � � � �ᨨ 盐ᆠ�   � 㦨҈� ᨨ盐㡰ᨨ ᆠ��泐҈鼀�ᆠᨨᆠ盐��矄� ᆠ � ᨨ  ᨨᨨ ᨨ 矄ᨨ 꾀矄鼀ᨨ  ᨨᨨ ᨨ ᨨ盐鼀҈ᆠ鼀 ├  � ᨨ盐矄 ᨨ犨 ᆠ��泐ᨨ 黨 �矄� ��ᨨ 矄 鼀� 盐鼀�  ᨨᨨ盐鼀ᨨ  ᨨᨨ �   ᨨ 泐ᨨ  矄ᨨ 꾀矄矄盐鼀  �ᨨᆠ�矄ᨨ盐�ᨨ 鼀� 矄 盐 � ᨨ鼀泐�  ᨨᨨ ᨨ  矄ᨨ  ҈ᆠ盐�㦨䰘맔҈҈ �矄� ��ᨨ 矄矄ᆠᨨ 㡰 ᲼҈黨黨㜠㝐├矄桌 � 꾀 盐ᆠ盐矄 X � ��泐  矄 盐 �ᨨ矄   ᆠ泐 ᆠᆠᨨ � �ᨨ ⼄盐�ᨨ  A 黨 X

®  Z Y +a

 ᲼҈黨黨҈㜠졔㝐├矄桌

㡰 �  盐矄ᨨ A Z�  ᨨᨨᆠ矄矄 㡰  �ᆠᨨ 盐ᆠ �  ᨨᨨᆠ矄矄�矄 ᨨ盐 ᨨ鼀ᨨ� ᆠ�ᆠ盐ᆠ├ᨨ  �盐矄҈҈鼀�  盐 � ᨨ鼀鼀� �ᆠ � ᨨ  矄 �   �泐 ᔼ

㝐㡰矄  盐� � ᨨᆠ矄矄  � � �  �泐ᨨ    盐ᆠ盐矄X

( ) ҈

෌�  m Y㡰㦨u錐m  n 㦨҈黨u

( )

( )

m   㦨u錐m ҈҈  㦨҈u

Topic-4 : Miscellaneous (Mixed Concepts) Problems 1 ҈



꾀 ᆠᆠ�  �  盐ᆠᨨᨨ泐矄盐 �  ᨨ矄��ᨨ

ᨨ ᆠ� 鼀ᨨ盐 ᨨ  �ᨨᆠ�鼀�ᨨ   㜠� ҈ 泐矄� 矄�  ᨨᨨ泐 矄矄    ��ᨨ

犨矄�鼀矄鼀ᨨ   鼀�矄矄�⼄盐�  ᨨ 矄 ᨨ�ᨨ ᨨ  ᨨᨨ泐␔ �矄 鼀� �鼀盐鼀

盐鼀 ᨨ  泐矄   犨 �ᆠ     ᨨᨨ泐ᆠ   ᆠᨨ 矄�  矄  ᨨ盐矄䁸  ᲼꾀 ҈桌 㡰  㡰 黨 ᆠ㡰 ҈ 㡰 ҈

ᆠᨨ矄�ᆠ �泐ᨨ ᨨᨨ 矄盐 � ᨨ鼀泐 �矄�盐  ᨨ盐� ᨨ盐矄 �ᆠ 盐ᆠ盐矄ᨨ  �盐矄 �矄�� 泐 쟼㦨



�矄 盐泐 盐 ᨨ   ᆠᨨ矄�ᆠ  �泐    �盐矄 ᨨ � ᨨ   盐ᆠ��矄 ҈ 鼀㦨҈҈�鼀㡰  ᲼꾀 ҈桌 㡰 � 鼀 㡰  鼀 ᆠ㡰  鼀 㡰  鼀   盐ᆠ盐矄 矄ᨨ� � �泐 ᆠ泐矄� ᨨ犨ᨨ a㜠�ᆠ矄     盐 ├ ᨨ犨  盐ᆠ盐矄  盐 ├ ᨨ犨

盐ᆠ盐矄�矄 ᲼҈黨黨黨和㜠㝐├矄桌 㡰 �ᨨ� 㡰 ᆠᨨ ᆠ㡰 ᨨᨨ

㡰 ᨨ 泐�



 �矄ᨨᨨ ҈ �  � �  鼀矄矄 ҈҈ 盐 盐 �ᨨ矄

MCQs with One Correct Answer

҈ b ᆠ泐ᨨ ҈  ᔴ  ᔴ  矄  ᆠ� 矄ᨨ   盐ᆠ盐矄

( ҈ ᔴã) ҈㝐ᨨ�矄�ᨨ盐 矄ᔼ ҈� 쟼 ᆠ泐矄

    㜠 ҈㡰  � πε 

ᨨ ҈  ᔴ ã  鼀 �鼀盐鼀├� �ᆠ �泐ᨨ  b�ᆠ�

҈�

鼀矄盐 鼀矄矄矄ᨨ   盐ᨨ  ҈҈  ҈� 䰘    졠

҈�盐҈䰘�盐҈�҈黨盐 ҈��盐 ҈� 矄ᆠ�泐෌�    ��ᨨ ᨨ   ҈� 䰘    졠

盐ᆠ�矄鼀҈盐㦨黨҈�㝐⏌ᆠ ᆠ�矄 矄 ᨨ �� 㡰 ⏌ pe㡰㦨҈㝐 鼀꾀矄矄盐鼀� �   ҈� �  ᆠ犨  � � � ��矄ᨨ  ҈� 䰘    졠

�

盐 �矄ᨨ 㝐�矄 ҈盐㦨黨҈�㝐⏌ᆠ犨 ᆠ�矄 矄 ᨨ �� � ᆠ盐盐鼀㡰 ᲼꾀 ҈桌 꾀 盐ᆠ ᨨ犨   矄盐泐� �ᆠ�ᆠ ᨨ犨 ᨨ  ��盐矄矄 �ᨨᆠ�鼀�ᨨ   � T泐矄矄  盐 鼀ᨨ盐 ᨨ  盐 ��

� ��矄矄盐ᆠ    ᨨ ᨨ犨 ⼄盐�鼀  ᨨ  ���矄 ҈�奠 ᨨ   ᆠ�ᆠᨨ犨� ᨨ鼀   �鼀ᔼ    �矄ᨨ鼀 ᨨᨨ犨  矄ᨨ  �� ᨨ鼀 �鼀盐鼀�ᨨ ᨨ nT泐矄   盐ᨨ n�矄 ᲼꾀 ҈�桌

WWW.JEEBOOKS.IN

P-299

Nuclei

Fill in the Blanks

4 

꾀ᨨ鼀矄 � � 矄鼀盐 �   ᆠ �矄ᨨᨨ矄 ᲼҈黨㜠㝐├矄桌

MCQs with One or More than One Correct Answer

6 䰘

҈ 꾀 �矄矄�ᨨ ᆠ�ᨨ �矄�� 泐 黨  ® �  +

黨  和

+ x + y

犨 x y犨ᨨ�ᆠ矄ᔴᨨ 矄� � �  黨  ᨨ 矄 ├� �ᆠ ��矄ᨨ  ᨨ 盐ᆠ矄  ᨨ 泐 KK和K 㝐㡰 ⧤泐 㝐㡰矄ᆠ�泐  黨 ҈ � � � ��矄 盐ᆠᨨ ᨨ   黨  �     和 



䰘�㝐�㝐 �㝐矄ᆠ�泐ᔴᨨ 矄� � � �  ᆠᨨ 矄�ᨨ 犨矄 ᆠᨨᆠᨨ�ᨨ 矄㡰�矄 㡰 ᲼꾀 ҈�桌 㡰 x㦨ny㦨n⧤和㦨҈黨㝐⧤㦨㝐 㡰 x㦨py㦨⧤和㦨҈黨㝐⧤㦨㝐 ᆠ㡰 x 㦨py㦨n⧤和㦨҈黨㝐⧤㦨㝐 㡰 x㦨ny㦨n⧤和㦨㝐⧤㦨҈黨㝐 꾀 矄 � ��泐 矄 ҈   盐ᨨ 矄 ᔼ ᨨ 盐ᆠ矄  �泐 �   ᨨᆠ矄矄矄 ҈   +҈   ®҈   + p  ҈







+҈  ®   + n ᔼ  �ᨨ犨 �

泐 矄�矄҈ ҈W  盐ᨨ 矄盐泐ᨨ  矄�矄  盐矄 � �鼀ᨨ  ᨨ ᨨ ᲼҈黨黨㜠㝐├矄桌 㡰 ҈s

㡰 ҈s

ᆠ㡰 ҈҈ s 㡰 ҈҈ s

鼀矄矄矄ᨨ   盐ᆠ�矄 ᨨᨨ犨矄 M   㡰 = ҈ 鼀盐錐

M p㡰㦨҈䰘鼀盐錐M n㡰㦨҈鼀盐錐 M  㡰 = ҈鼀盐 7 黨

Match the Following

ᨨ盐 泐矄�ᆠ⼄盐 ��矄�矄 � ᔴᨨ盐鼀 ᔼ �盐矄 �矄 � ᔴᨨ盐鼀 ᔼᔼ�  ᨨ鼀ᨨ ᲼҈黨䰘㜠㝐├矄桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 㡰 鼀 �泐ᨨ 㡰  �鼀ᨨᆠ盐矄ᨨᨨ鼀 鼀 㡰 � � � �泐ᨨ 㡰  泐 盐ᆠ�

盐ᆠᨨ

ᆠ㡰 㜠泐 ᨨᨨ  �泐 �㡰 ҈├ 㡰  ᨨᨨ   �泐ᨨ 㡰 䰘㝐 �矄��� 

ᆠᨨᆠ鼀ᆠ � �ᨨ ᔴᨨ盐鼀 矄ᔼ ᔼᔼ�矄�� 泐 㡰 a  e, b  h, c  g, d  f 㡰 a  e, b  g, c  f, d  h ᆠ㡰 a  f, b e, c  g, d  h 㡰 a  f, b  h, c  e, d  g

҈ ᔴᨨ盐鼀 㜠ᔼᔼ��矄ᆠ� 矄泐矄鼀矄盐 �ᨨ� �ᨨᆠ矄矄 ᔴᨨ盐鼀 㜠ᔼ矄盐��矄矄ᆠ  �矄�  矄ᨨ鼀ᨨ  鼀矄  ᨨ 矄泐矄鼀㝐ᆠ  矄鼀 矄� ᔴᨨ盐鼀 㜠ᔼ ᨨ ᨨ�ᨨᆠ矄矄 矄㡰 ᨨ鼀ᔴᨨ盐鼀 㜠ᔼᔼ ᲼黨桌 ᔴᨨ盐鼀 㜠ᔼ ᔴᨨ盐鼀 㜠ᔼᔼ 꾀㡰  �泐ᨨ   㡰 System 꾀ᆠᆠ�ᨨ� ��泐 矄泐矄鼀�矄� ᆠ矄 盐 ᆠ � Prᨨcess ᔼ�矄ᆠᨨ

ᆠ ᨨ泐 㡰 㝐ᆠ  �ᆠ �泐 ⼄㡰 System  꾀�矄� 

�矄ᨨ�  ᨨ   ��ᆠᆠᨨ �  � 矄泐矄鼀犨 �ᆠ �矄 犨�   ��ᆠ�矄ᨨ

ᆠᨨ  � ᨨ �泐 Prᨨcess �矄�矄 ᨨ  ᨨ鼀鼀ᨨ�ᨨ ᨨ ᆠᨨ鼀矄矄  泐盐矄 � � �矄矄  �矄ᨨ

ᔴ㡰 ᔼ   �泐 㡰 System꾀�矄� ��� ᨨ  矄泐矄鼀�矄 ᆠᨨ �  ᆠᨨ  � ᨨ�矄 Prᨨcess �矄�矄 鼀ᆠ  �ᆠ �泐 ᆠᨨᨨ  盐ᨨᆠᨨ  鼀ᨨ矄 矄盐ᨨ盐 � �� 㡰 㝐矄矄ᨨ  矄泐矄鼀 矄㡰 System꾀 泐 盐ᆠ盐矄 �矄 ᆠ矄 � ��泐矄 Prᨨcess  盐ᆠ盐矄 �矄矄�ᨨ 矄� ᨨ犨ᨨ �鼀 矄 ᨨ  泐⼄盐鼀矄矄矄  矄ᨨ鼀 盐ᨨ 矄 鼀� 㡰 System 꾀矄�矄�犨�ᨨᨨ Prᨨcess ᨨᨨ�矄 ᆠ � �鼀泐� � 鼀� �ᆠ �  �ᆠ盐ᨨ�矄  ҈҈ ᔼ   ᨨᨨ犨� �ᆠᨨ盐鼀 ᔼ�矄矄矄ᨨ鼀 泐矄�ᆠ⼄盐 ��矄     ᆠᨨ盐鼀  ᔼᔼ ��矄 ᨨ �鼀  �泐 盐矄 矄矄ᨨᆠ� 犨� 矄ᨨ鼀ᨨ  鼀ᔴ ᨨᨨ矄 ᨨ�盐 ᨨ  �泐 ᨨ鼀ᆠᨨ盐鼀 ᔼᔼ ᨨᆠ ᨨ   泐矄�ᆠ⼄盐 ��矄 � ᆠᨨ盐鼀 ᔼ 犨� ᆠᨨ矄ᨨ � �⼄ᆠ �� 矄  盐鼀 꾀㡰 㡰 ᔴ㡰 㡰ᆠᨨ   泐矄�ᆠ ⼄盐 �泐�   矄犨ᨨᨨ├ᔼ 泐ᨨ盐 矄犨 矄⼄盐 ᆠ ᨨ ᆠᨨ盐鼀 ᔼ矄 ᨨ盐 鼀� �   ᲼҈黨黨䰘㜠㝐├矄桌 ᔴᨨ盐鼀 ᔼ ᔴᨨ盐鼀 ᔼᔼ 꾀㡰 쟼 �泐ᨨ  鼀 㡰 �

盐ᨨ 矄 㡰 쟼 �泐ᨨ 㜠泐矄 ⼄㡰 � ᔴ㡰 � � � �泐 㡰 

盐ᆠᨨ

㡰  ᨨᨨᆠ�ᆠ 矄㡰   矄 ᨨ ᨨ 鼀 㡰 ҈├ 盐㡰 㝐

WWW.JEEBOOKS.IN

EBD_8341 P-300

Physics

8

Comprehension/Passage Based Questions

矄矄�㜠҈

b 㜠 ᆠ泐ᨨᆠ矄矄 �矄ᆠᨨ ᨨ盐 ҈黨�矄矄�ᆠ泐  ᆠ泐ᨨ  盐ᨨ  n㡰ᔼ  ᨨᨨ泐ᨨᨨ  p㡰 

ᆠᨨ  e㡰ᨨ矄 矄  ᆠ泐ᨨ 盐ᆠ矄ᨨ   盐ᨨ 

 ᨨ ᆠᨨ 矄� � �   ᆠ泐ᨨ  盐ᨨ  矄 犨ᨨ㜠ᨨ 泐 ᆠ泐ᨨᆠ矄矄 � 犨矄 �ᆠ   ᨨ�ᆠ泐   ├� �ᆠ  �泐ᨨ  ᆠᨨ 矄 ᨨ盐 ᆠᨨ 矄 盐 �鼀 泐 �犨矄ᨨ矄   ᆠᨨ ├� �ᆠ �泐 矄ᆠᨨ � 盐ᨨ盐矄 矄ᆠ盐鼀 ᔴᨨ 矄� � �   㜠ᨨ 泐 ᆠ泐 ᨨᆠ矄矄 � n ® p + e - + n e  ᨨ盐  ҈黨 盐�  �     ᨨ矄

ᆠᨨ  �泐矄ᆠ盐鼀꾀矄矄盐鼀� �  �㜠 盐� ᨨ ne 㡰 ᨨ 鼀矄矄矄矄 ᨨ矄矄矄矄� � ���� �泐   盐ᨨ

ᨨ矄鼀ᨨ鼀 盐鼀  �泐ᆠᨨ 矄�ᨨ � ᆠ�矄 �  ᨨ鼀 �矄ᆠᆠ盐�ᨨ  鼀 �鼀盐鼀├� �ᆠ �泐ᨨ  ᆠᨨ �矄맔҈ ├� �ᆠ �泐ᆠ� 泐  ᨨᨨ �矄ᨨ 泐 ᆠᨨ� �泐 ҈ ᔼ   �㜠 盐� ᨨ  鼀矄矄ᨨ ⏌ᆠ 犨 ᆠ�矄  矄 ᨨ �� 㡰� 矄 ᨨ  ᨨ鼀矄矄犨 矄 ᨨ盐    �ᨨ  ├� �ᆠ �泐Kᨨ  ᆠᨨ 䁸 ᲼҈桌 6

㡰 0 £ K £ 0.8 ´ ҈0 eV 6 㡰 .0 eV £ K £ 0.8 ´ ҈0 eV 6 ᆠ㡰 .0 eV £ K < 0.8 ´ ҈0 eV 6

㡰 0 £ K < 0.8 ´ ҈0 eV ҈

␔ �矄 鼀 �鼀盐鼀 �泐ᨨ   �㜠 盐� ᨨ䁸 ᲼҈桌 㡰 ᨨ 㡰

㝐盐ᆠ 矄矄  맔҈

ᆠ㡰 泐맔҈ 㡰 㝐盐ᆠ �  맔҈ 矄矄�㜠 和ᆠ� �矄矄犨ᨨ├� �  ᨨ ᨨ 盐ᆠ 盐矄�ᨨ ᆠᨨ 盐ᆠ�ᨨ  泐 泐 ᨨ�  ҈ H ├ ᨨ犨 矄 盐ᨨ    ᨨ 泐ᆠ  ᨨ盐� ᨨ 矄ᆠ �  ᨨ 盐矄�ᨨ ᆠᨨ  㜠ᆠ�ᨨ �矄 ҈  + ҈  ®  + n +  �泐ᔼ   ᆠᨨᨨ 盐矄�ᨨ  ᆠᨨ  �矄ᨨ  泐 泐 ᨨ�  �矄 盐泐�ᨨ �   � ᨨ 盐ᨨ  盐ᆠ� ᆠᨨ 矄 �矄ᆠᨨᆠ�ᨨ ᨨ  ҈ H 盐ᆠ� ᆠᨨ 矄�矄├ ᨨ犨 矄矄鼀  盐ᆠ�鼀ᨨ ᨨ鼀泐�   ᆠᨨᆠᨨ ᨨᆠᆠ矄�ᨨ 泐ᆠᨨ鼀ᆠᨨ矄 ᨨ盐�  ᨨ 盐ᆠ 盐矄�ᨨ ᨨ├ᆠ矄盐泐 鼀盐矄�  ᆠᨨ ᆠᨨᨨᨨ ��   ᨨ鼀�犨ᆠ 盐矄 ᨨᆠᨨ �   矄鼀和ᆠ�ᆠ �⼄盐矄盐矄 犨 �ᆠ ᆠᨨ �  矄鼀 ᨨ�鼀t0 ᨨ �ᆠ矄 泐犨泐 ᨨ鼀 ᆠᨨᔼ n �矄   矄�泐 盐鼀⏌ᨨ盐鼀㡰ᨨ  盐ᨨ 矄 ᨨ 盐ᆠnt0 �矄ᆠ

犨矄ᨨ  盐鼀 ᔼ  ᨨ  ᨨ    ᆠ��  ᆠᨨ �矄 鼀 矄盐ᆠᆠ矄矄 盐� 犨矄ᨨ  盐鼀�矄�  �맔҈ ҈矄⏌ᆠ鼀 ᔼ鼀泐  盐ᨨ盐矄  ᨨᨨ犨� �ᨨ 鼀

ᆠᨨ 矄  k = 맔҈�⏌⧤錐

e 㦨҈맔҈黨鼀 pe 

᲼黨桌

҈ ᔼ    ᆠᨨ ᨨ  盐ᆠ 盐矄�ᨨ  ᆠᨨ   �矄 ᆠᨨ鼀矄 矄鼀ᆠ盐矄ᨨ 㡰 矄ᨨ � 盐ᆠ ᨨᆠᆠ� �犨   盐ᨨ 矄 㡰 ᆠᨨ盐ᨨ鼀 ᨨᆠᆠ� �犨   盐ᨨ 矄 ᆠ㡰 ᆠᨨ盐ᨨ鼀 ᨨᆠᆠ� �犨  盐ᨨ 㜠ᆠᨨ �矄 㡰   �� 鼀盐鼀� �  � 矄�  ᆠᨨᆠᨨ ҈� 꾀矄矄盐鼀  犨ᨨ 盐ᨨ  盐ᆠ� �    ᆠᨨᨨ  盐矄�ᨨ

ᆠᨨ鼀盐T鼀ᨨ� �ᨨ犨 矄ᆠ ᨨ  ᆠ  犨�  ├� �ᆠ  �泐 ҈� kT, 犨     矄�ᨨ

犨  鼀�矄� ᨨ盐� ᨨ �ᆠᆠᨨ盐ᨨ鼀ᨨ �  �泐꾀矄ᨨ �ᆠ 泐� ᆠ�ᨨ  ᨨ鼀ᨨ �ᆠ矄 �  ᆠᨨ 鼀� �鼀盐鼀鼀盐T⼄盐�  ᨨ 鼀 ᨨᆠ 矄�ᨨ ᨨ 맔҈҈�鼀�矄�   � 㡰 ҈맔҈黨⧤T맔҈黨 ⧤ 㡰 맔҈黨⧤T맔҈黨 ⧤ ᆠ㡰 맔҈黨⧤T맔҈黨 ⧤ 㡰 맔҈黨⧤T�맔҈黨 ⧤ ҈ 矄盐矄ᨨ ᆠᆠ盐�ᨨ 矄 ᨨ ᨨ盐 �   矄�� 矄ᨨ  盐矄�ᨨ

ᆠᨨ盐矄� �㜠ᆠ�ᨨ �� ᨨ犨␔ �ᆠ ᨨ  矄 �矄鼀ᨨ矄ᨨ鼀�矄� �矄 ᨨ 犨矄ᨨ ᆠ��ᨨ 䁸 㡰 盐ᨨ   矄�泐㦨맔҈҈ᆠ鼀 ᆠᨨ � 鼀 �鼀㦨�맔҈矄 㡰 盐ᨨ   矄�泐㦨맔҈҈ᆠ鼀 ᆠᨨ � 鼀 �鼀㦨黨맔҈҈矄 ᆠ㡰 盐ᨨ   矄�泐㦨맔҈ᆠ鼀 ᆠᨨ � 鼀 �鼀㦨҈맔҈҈҈矄 㡰 盐ᨨ   矄�泐㦨҈맔҈ᆠ鼀 ᆠᨨ � 鼀 �鼀㦨맔҈҈矄 10 Subjective Problems ҈䰘 �� 泐 ��ᆠᆠᨨ 矄ᨨ鼀  ᨨ �ᨨ  鼀 ᆠᨨ � � � 盐ᨨ 矄 �ᨨᨨ  ��ᨨ

盐ᆠ盐矄ᨨ ᨨ �盐鼀 盐ᆠ盐矄�矄 ҈㡰҈⏌ �  㡰ᨨ鼀�ᆠ

盐鼀ᨨ   盐ᆠ盐矄 㡰  ⼄盐 ᆠ泐ᨨ Ka� ᨨ   㜠泐ᨨ 盐ᆠ  R㦨҈҈맔҈䰘鼀҈ c㦨맔҈鼀⏌矄㡰 ᲼�㜠㝐├矄桌 ҈ 꾀 盐ᆠ盐矄矄盐 �ᨨ矄 ᆠ泐鼀�� � a�ᆠ ᨨ  㜠ᨨ��犨 � l㦨�䰘´҈㜠҈�鼀ᔼ  鼀矄矄ᨨ   盐�  盐ᆠ盐矄�矄҈鼀盐  ᨨ  a �ᆠ矄�矄鼀盐 鼀�  ᨨ├� �ᆠ �泐 �   � 矄 ᆠᨨ�  鼀矄矄ᨨ   

盐ᆠ盐矄� 鼀盐 ҈鼀盐㦨黨҈䰘㝐⏌ᆠ㡰 ᲼҈㜠�㝐├矄桌

WWW.JEEBOOKS.IN

P-301

Nuclei ҈

 鼀  ᔴ盐�盐鼀 248 96  ᔴ鼀  矄  鼀 �  ᨨ ҈

҈黨

矄ᆠᨨ 矄 ᔼ矄 �鼀泐 ᆠ泐 鼀ᨨ 矄  矄ᨨ  ᨨ盐矄 �矄矄�ᨨ  a㜠 ᆠ泐  ᨨ鼀犨� ᨨ��泐ᨨ 奠   犨� ᨨ��泐ᨨ 黨奠쟼ᆠ  �矄矄�ᨨ 矄矄 㝐ᨨ  �泐 鼀矄矄矄� ᨨ � a㜠 ᆠ泐矄



ᨨ ҈ᔴ鼀ᨨ鼀矄 ҈盐㦨黨҈㝐⏌ᆠ㡰

᲼҈黨黨䰘㜠�㝐├矄桌

꾀鼀ᨨ ᨨᆠ ᨨ鼀�ᆠᨨ� 矄ᨨ盐ᆠ �� �犨 �  处犨� ᨨ犨犨 盐Aᨨ  �鼀҈鼀  � 矄ᆠ  SC  ᆠ  矄 矄 ᨨ犨  �  �� 꾀  ᨨᨨ鼀�矄矄� ᆠᨨDᨨ 矄盐 ᆠ�ᆠ鼀�矄ᆠ  ᆠ ᨨ  矄ᆠ   �ᆠ� ᆠ泐ᨨ   ᆠᨨ ᨨ  ᨨᨨᆠᨨ � �ᨨ � ᆠ�   ᨨᨨ �矄 黨 ᲼҈黨黨҈㜠졔졔㝐├矄桌





 鼀

鼀

244 ᨨᨨ犨矄 248 96 ᔴ鼀㦨䰘u 94 盐㦨҈u 4 2 㦨uᔴᆠ盐 ᨨ犨ᨨ盐盐 ᨨ鼀矄鼀

和ᔴ



㡰 ᔴᆠ盐  ᨨᨨ  盐  ᆠ ᨨ  矄ᆠ

   ᨨᨨᆠ盐 �   ᆠᨨ 㡰 ᔼ  ᆠᨨ ᆠ 矄Lᨨ  ᨨᆠ � 鼀�矄� 矄 �    盐 矄 矄 ᨨ犨  �    犨盐矄 ᨨ  ᨨᨨ  盐     ᨨᨨᆠ盐  꾀矄矄盐鼀  盐 � ᨨ鼀 � 矄鼀�矄矄�ᨨ ᨨ 奠 ᨨ鼀  矄 ᆠ㡰 ᔼ  犨ᨨ├ 盐 ᆠ�ᨨ ᨨ   ᨨᨨ鼀�矄矄�矄盐 ᆠ�矄 ҈ᆠᆠ盐 盐矄ᨨ  矄ᨨ� �ᨨ ��   犨ᨨᆠ矄矄 犨� ᨨ盐 犨�   矄�  盐㡰 ҈ ᨨ犨鼀 泐ᆠᨨ ᨨᨨ 矄  盐ᨨ 矄 � 

盐ᆠ盐矄ᨨ ᨨ鼀�ᆠ 盐鼀҈҈ 鼀矄矄 盐鼀䁸 ᲼҈黨㜠㝐├矄桌 �㡰 盐鼀ᨨ ᆠᨨ 矄㦨 ��㡰 盐鼀ᨨ ᨨᨨ 矄㦨 ���㡰 盐鼀ᨨ  盐ᨨ 矄㦨

Answer Key Topic-1 : Composition and Size of the Nuclei ҈



 㡰

 ᆠ㡰

 㡰

� 㡰

 矄㡰 䰘 ᆠ 㡰

Topic-2 : Mass-Energy Equivalence and Nuclear Reactions ҈ 㡰  ᆠ㡰  㡰 ҈҈ 㡰 ҈ 盐矄�ᨨ 㡰 ҈黨 ᆠ㡰

 㡰 � 㡰 ҈ 盐� ᨨ㡰

 ᆠ㡰 䰘 ᆠ㡰  㡰 ҈ 㡰 ҈�  㡰 ҈ ᆠ 㡰

黨 ᆠ㡰 ҈ ᆠ㡰 ҈䰘  㡰 ҈ 㡰

Topic-3 : Radioactivity ҈ ҈҈ ҈ ҈ 黨 

ᆠ㡰 㡰 㡰 �㡰 ᆠ㡰 ᆠ㡰

 ҈    䰘

㡰  ᆠ㡰  㡰 � 㡰 ҈ ᆠ㡰 ҈ 㡰 ҈� 㡰  ᆠ㡰  㡰 � 㡰  㡰  ҈㡰 � ᆠ㡰 ҈ 㡰  㡰  꾀®⼄錐®錐ᔴ®矄錐®⼄

㡰 㡰 㡰 㡰 㡰

 ҈    

ᆠ㡰 䰘 㡰 ҈䰘 㡰 䰘 � �盐鼀䰘㡰 ᆠ㡰 � 㡰 黨

㡰 ᆠ㡰 㡰

 ᆠ㡰 黨 㡰 ҈ 㡰 ҈ 㡰 ҈黨 㡰  ᆠ㡰  ᆠ㡰 黨 ᆠ㡰  㡰 䰘 㡰  � 矄҈� 矄㡰 꾀®錐®矄錐ᔴ®⼄錐®⼄ ᆠ㡰

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈ 黨 ҈�

ᆠ㡰 㡰 㡰

 ᆠ㡰  㡰  黨㡰 ҈ 꾀®⼄錐®⼄錐ᔴ®矄錐®矄 ҈ 㡰

� 㡰  ᨨ鼀�ᆠ 盐鼀鼀矄矄 盐鼀㡰 䰘 㡰 ҈҈ 꾀®錐®錐ᔴ®盐錐® ҈ 㡰 ҈ ᆠ㡰

 ᆠ㡰 ҈ 㡰

WWW.JEEBOOKS.IN

EBD_8341 P-302

Physics

Semiconductor Electronics: Materials, Devices and Simple Circuits

28

Topic-1 : Solid Semiconductors and P-N Junction Diode 1 ҈



␔� � ᆠ矄� ��矄� �ᨨ�ᨨ  ᨨᨨ �ᨨ   ᨨ㜠 ᨨᆠ盐 鼀� �盐  ᲼㝐� 和� ᔼ㡰桌 㡰 鼀� 矄ᆠᨨ 矄  㡰 � ᆠ矄矄� ��泐  � � �ᆠ� 盐� ᆠ矄矄 ᆠ㡰 ᔼ ᆠ矄矄� 泐 㡰 � ᆠ矄矄� ��泐 矄盐矄 � 泐

犨ᨨ  �ᨨ 矄 A B㡰 � �├ ᨨ犨 ᨨ�矄 ᨨ  矄ᆠ�泐ᆠᨨ

ᆠ 矄矄 ᨨ犨 �   ᆠ�ᆠ盐�ᨨ犨 ᨨ盐盐ᨨ�V��ᨨ 犨� � 盐 ᨨ�� 泐� ᆠ矄� �犨� �鼀�矄�� 泐 V� 盐㦨t㦨㡰 ��盐矄⼄盐��㡰 ᲼㝐� 和� ᔼᔼ㡰桌

B A V�



㡰 �鼀



├ ├ ᨨ犨 ᨨ�ᨨ     �ᨨ 盐矄 �   �� ᆠ�ᆠ盐�矄 ᨨ � 盐ᨨ�矄 ᨨ犨 �  ��盐 ᨨ犨 �鼀��ᨨ ᨨ  ᨨ盐盐ᨨ��矄 ෌ 矄 犨 矄ᆠ 鼀�ᆠ  ᨨᨨ矄ᆠ㡰 [Main Sep.04, 2020 (I)] ҈ ҈

�

V㦨



҈ V

㡰 t V

 㦨W





V

MCQs with One Correct Answer

㡰

V

҈W

t

V

ᆠ㡰

V

t



㡰

V



�鼀 

V



㡰 �鼀 

V



ᆠ㡰 �鼀



t

␔   �ᨨ �矄 ᨨ犨 �矄 � 矄ᨨ� ᨨᨨ �

矄 �鼀�ᨨ ᆠ盐  ᨨ盐�   �ᨨ �矄҈鼀꾀ᔼ  泐ᨨ 鼀 ҈��矄盐矄 �  ᆠ�ᆠ盐� 盐ᨨ 鼀� �鼀盐鼀 矄�矄 ᆠᨨᆠᨨ

ᆠ � 矄�矄犨�   �ᨨ 矄ᨨ   ᆠ盐  ᨨ矄 ᨨ ᆠ  矄 �鼀��矄[Main Sep. 03, 2020 (I)] 㡰 W 㡰 �W ᆠ㡰 ҈W 㡰 W

WWW.JEEBOOKS.IN

P-303

Semiconductor Electronics : Materials, Devices and Simple Circuits

�

ᔼ 矄鼀�ᆠᨨ 盐ᆠᨨ ᨨᨨ �ᨨ ᆠ  ᆠ ᨨᨨ 犨�  鼀 �鼀盐鼀犨 � ᨨ  鼀  �矄 � �泐�矄  ᆠ├Ἐ矄ᆠᨨ 矄 h㦨맔҈矄 和 ᨨ ��  c㦨맔҈鼀⏌矄᲼㝐� 和 ᔼᔼ㡰桌 㡰 ҈҈ 㡰  ᆠ㡰 ҈� 㡰 ҈



ᆠ盐 ��   犨ᨨ├�矄 ᲼㝐� 黨 ᔼᔼ桌

㡰 �鼀꾀 㡰 ҈�鼀꾀 ᆠ㡰 䰘�鼀꾀  㡰 �鼀꾀 ҈ 矄├ ᨨ犨 ᨨ�ᨨ   �ᨨ �矄��

 �� ᆠ�ᆠ盐�

ᆠ盐 Iz ᨨ盐�   �矄᲼㝐� 꾀�҈黨ᔼ桌 㡰 ҈鼀꾀 㡰 ҈䰘鼀꾀 ᆠ㡰 ҈�鼀꾀 㡰 䰘鼀꾀 ҈҈ ᔼ  �� ᆠ�ᆠ盐� ᆠ盐  ᨨ盐�  �ᨨ �矄ᆠᨨ矄ᨨ ᲼㝐� ҈҈ ҈黨ᔼ桌 ҈ �W

҈

䰘

㡰 꾀 㡰 꾀 ᆠ㡰 꾀 㡰 꾀

犨ᨨ�  �ᆠᆠᆠ�ᨨ矄꾀 ᆠ �  ᨨ 矄鼀 ᨨ � �  ᆠᨨ

ᆠ �  犨ᨨ �   ᆠ�ᆠ盐�矄 矄 矄 ᨨ犨 ᨨ犨�鼀t㦨ᔼ  ᆠ �ᨨ ᆠᆠ�ᨨ矄꾀  �鼀t㦨ᔴ �矄턼꾀 턼矄ᆠ�泐    �矄 矄ᨨ  盐ᨨ�� 鼀㡰 ᲼㝐� 黨 ᔼᔼ桌

 ҈�W

㡰 鼀꾀 㡰 䰘鼀꾀 ᆠ㡰 鼀꾀 㡰 鼀꾀 ҈ ᆠ�ᆠ盐�矄 ᨨ犨 ᨨ犨ᆠᨨ � 矄犨ᨨ�  �ᨨ 矄ᆠ 犨�  ᨨ犨 矄�矄 ᆠᨨ �Wᔼ  泐ᨨ��矄  ᆠ盐  ᨨ盐�  ҈W矄�矄 ᆠ � 꾀鼀矄㡰 �矄  ᲼㝐� ҈҈ ҈黨ᔼᔼ桌 ҈�W



㡰 턼꾀㦨



ᔴ ᔴ 턼㦨 e 

䰘�W

㡰 턼꾀㦨ᔴ턼㦨ᔴ

ᔴ ᔴ ᔴ ᆠ㡰 턼꾀㦨ᔴ턼㦨 㡰 턼꾀㦨 턼㦨 e e  ᔼ   ��盐ᨨ � �  ᆠ犨 A B�矄 ᲼㝐� 䰘 ᔼᔼ桌

 㦨҈ 

 ҈W 

㡰  㡰  ᆠ㡰 䰘 㡰  ҈ ᨨ   ᆠ�ᆠ盐� 矄 ᨨ犨  ᨨ犨   ᆠ盐   ᨨ盐�      �ᨨ  �矄    ᲼㝐�  ҈   ҈黨 ᔼᔼ桌

�├W

黨

㡰 ҈ 㡰 � ᆠ㡰 ҈� 㡰 ᨨ ��盐矄 ᨨ犨矄ᔴᨨ��盐ᨨᆠ�ᆠ盐�犨�   �ᨨ ᨨ ├ ᨨ犨 ᨨ�㦨ᔼ  盐 �盐 � 盐 ᨨ� �矄犨  ҈ ᨨ҈    犨  �矄   鼀 �鼀盐鼀 ᆠ盐 䁸 ᲼㝐� ҈꾀҈黨ᔼᔼ桌

҈

�

҈├W

㡰 黨鼀꾀 㡰 �鼀꾀 ᆠ㡰 ᨨ 㡰 ҈鼀꾀 ҈ 㝐ᨨ��泐ᨨ ᆠᨨ 矄� 矄鼀�ᆠᨨ 盐ᆠᨨ�矄  �  矄  �ᨨᨨ  � � ᨨᆠ�泐ᨨ � ᆠ�ᆠ � ᔼ  ᨨ   㜠泐矄鼀�ᆠᨨ 盐ᆠᨨ   矄�泐ᨨ ᆠᨨ 矄�矄҈҈黨鼀    �鼀ᨨ��泐�矄҈鼀⏌ 矄㡰   矄�矄��泐ᨨ   矄鼀�ᆠᨨ 盐ᆠᨨ 矄� ᆠ � �矄   㜠泐 矄鼀�ᆠᨨ 盐ᆠᨨ ᆠᨨ �盐�ᨨ ᨨ  ᨨ矄�矄�� ᨨ 㡰�矄ᆠᨨ矄ᨨ ᲼㝐� 黨 ҈黨ᔼ桌 㡰 W鼀 㡰 W鼀 ᆠ㡰 W鼀 㡰 W鼀

WWW.JEEBOOKS.IN

EBD_8341 P-304

҈�

Physics

和�

҈

҈



෌  和� �ᨨ 矄 矄 ᆠᨨ 盐ᆠ� �     䰘  矄ᆠ�泐 ᔼ    ᨨᨨ犨� � ��盐 �  ෌ �ᨨ  ᆠᨨ

ᆠ�ᨨ   矄    盐 ᨨ ᨨ ᆠ  �矄 泐  矄矄盐鼀  ෌ �ᨨ  矄�├ ᨨ犨 ᨨ�㡰 ᲼㝐� 黨 ҈黨ᔼᔼ桌 ෌ ᨨ



㡰  㡰  ᆠ㡰  㡰 

 � �ᨨ  鼀鼀 ᨨ矄��ᆠᨨ  �ᨨ �  ��

ᆠ�ᆠ盐��矄 ᲼㝐� ҈桌 

W



҈䰘

҈ �W ҈�

҈�W 

҈

҈黨



 㦨҈





�㡰

҈



㡰 �鼀꾀 㡰 鼀꾀 ᆠ㡰 ��鼀꾀 㡰 䰘鼀꾀 ␔ �矄 ᆠᨨ 盐ᆠ��泐ᨨ 矄鼀�ᆠᨨ 盐ᆠᨨ矄鼀 � � ᆠᨨ ᆠᨨ ᆠ �ᨨ ᨨ �맔҈҈鼀 ᨨᆠᨨ ᆠ �ᨨ

ᨨ �맔҈҈黨鼀ᆠᨨ 鼀ᨨ��泐ᨨ 鼀҈矄҈ ᨨ鼀ᨨ��泐ᨨ ҈鼀҈矄҈䁸 ᲼㝐� 졠 � 꾀�҈䰘桌 ├ᆠ �ᨨ ᆠᨨ 矄҈맔҈҈黨ᔴ㡰 㡰 ҈ W鼀㡰҈ 㡰 ҈ W鼀㡰҈ ҈ ᆠ㡰 �黨 W鼀㡰 㡰 ҈ W鼀㡰҈ ᔼ  � 泐 矄鼀�ᆠᨨ 盐ᆠᨨ �ᆠ矄犨 ᨨ矄ᆠ ᆠ�矄�ᆠ矄 �� ᨨ犨�  ᨨ  �㡰 ��㡰 ���㡰 �㡰 ᲼㝐� ҈桌



��㡰

ᔼ  矄�泐 ᨨ �� 

ᔼ盐鼀� 

�⧤

㡰  㡰 ҈�鼀꾀 ᆠ㡰 11.5 鼀꾀 㡰 13.5鼀꾀 ᔼ  �� ᆠ�ᆠ盐� ᆠ盐  ᨨ盐�    �ᨨ �矄 ᲼㝐� 졠 � 꾀�҈҈桌

矄�矄 ᆠ

├



���㡰 �㡰 㡰 和ᨨᆠ��    矄�矄 ᆠ  �ᨨ  矄�鼀 �ᨨ  㡰   �ᨨ 和ᨨᆠ矄�鼀 �ᨨ ��     矄�矄 ᆠ ᆠ㡰 和�鼀 �ᨨ   �ᨨ 和ᨨᆠ��     矄�矄 ᆠ 㡰   �ᨨ  和�鼀 �ᨨ  ��     矄�矄 ᆠ和ᨨᆠ

 鼀盐   ᆠ ᨨ  矄�矄 ᆠ矄 ᨨ  ᔴ盐  盐 ᨨ 和��  鼀盐 �㜠⧤�矄矄 矄ᆠ� 泐 ᲼㝐� ҈桌 㡰 � � ᆠ矄 ᨨᔴ盐 ᨨ  � ᆠ矄ᨨ 和� 㡰 �  ᆠ矄 ᨨᔴ盐�  ᆠ矄 ᨨ和� ᆠ㡰 � � ᆠ矄 ᨨᔴ盐� � ᆠ矄 ᨨ和� 㡰 � � ᆠ矄 ᨨᔴ盐 ᨨ  �� ᆠ矄 ᨨ和� 꾀   �鼀  �矄  ᨨ鼀  ᨨ 鼀�    ҈ ᆠ ᆠ�矄�ᆠ矄ᨨ   �ᨨ 犨 �ᆠ  矄ᨨᆠ� 矄�矄 ᆠᨨ  㦨҈W 鼀 �鼀盐鼀ᨨ犨ᨨ  �矄矄��ᨨ

� �ᨨ ҈␔ 鼀� �鼀盐鼀ᨨ� �ᨨ  ᔴ矄ᨨ盐ᆠ �  ᆠ�ᆠ盐��矄 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 � 㡰  ᆠ㡰 ҈ 㡰  꾀 쟼鼀�矄�� ҈犨盐 � ᨨ鼀泐ᨨ盐 �  鼀�盐 ᨨ  ᆠ�ᆠ � ᨨ  ��  �矄 ᆠᨨ ҈鼀 ᨨ鼀  �ᨨ �矄 ᲼㝐� ҈�桌 㡰 �⏌鼀 㡰 䰘䰘�⏌鼀 ᆠ㡰 ҈䰘⏌鼀 㡰 �⏌鼀 꾀  泐 �矄 ᆠᨨ

ᆠ ᆠᨨ矄矄 꾀 矄 矄 ᨨ犨 �   ��盐 盐ᨨ  ᆠ盐 矄盐� 泐 泐 犨  � ᨨ ᆠ矄泐矄ᨨ矄��鼀� �矄ᆠᨨ

ᆠ ᨨ꾀 � ᨨ ᆠ矄犨  ᨨ矄��鼀� ᨨ 泐 �矄 ᆠᨨ

ᆠ  ᨨ  犨� 矄ᆠ�泐  ᲼㝐� 졠 � 꾀�҈҈ ҈�桌 ҈

�W



҈W

 꾀



㡰 꾀 꾀 㡰 꾀 꾀 ᆠ㡰 ҈꾀 꾀 㡰 꾀 ҈꾀   ᨨ犨 �矄  �ᨨ ᆠᨨ

ᆠ�ᨨ �矄 ᲼㝐� ҈桌 㡰

+2V

–2V

㡰

–3V

–3V

ᆠ㡰

2V

4V



–2V

+2V

WWW.JEEBOOKS.IN

P-305

Semiconductor Electronics : Materials, Devices and Simple Circuits

�

꾀   �ᨨ  �矄 ᆠᨨ

ᆠ  ᨨ  泐   ᨨ  矄 矄 ᨨ犨ᨨ犨 ᲼㝐� 졠 � 꾀�҈҈҈桌 ├W ᔼ 꾀

ᔼ



150W

 㦨├W

҈㦨



黨 ᆠ�ᆠ盐�矄 ᨨ犨 �   ��盐ᆠᨨ � 矄犨ᨨ �ᨨ 矄ᆠ 犨�  ᨨ犨 矄�矄 ᆠᨨ �ᨨ 鼀矄 犨� � � � ᆠ├犨 矄�矄 ᆠᔼ  泐ᨨ��矄 ᆠ盐   ᨨ盐�  ҈ᨨ 鼀矄�矄 ᆠ � 鼀矄㡰�矄 ᲼҈黨黨䰘㜠҈㝐├桌

50 W





ᆠ盐 矄ᔼᔼ ᔼ矄ᆠ�泐 㡰 ҈�鼀꾀�鼀꾀҈鼀꾀 㡰 ҈�鼀꾀䰘�鼀꾀䰘�鼀꾀 ᆠ㡰 ҈�鼀꾀�鼀꾀䰘�鼀꾀 㡰 ҈�鼀꾀䰘�鼀꾀�鼀꾀

ᔼ㜠ᆠ ᆠ�矄�ᆠᨨ  쟼�矄 ᲼㝐� ҈桌

㡰



㡰



 ෌ Ӹ

 



Ӹ 㡰 ෌ 

ᆠ㡰 졠

䰘



졔  

t

1



V A







㡰 �鼀꾀 㡰 ҈鼀꾀 ᆠ㡰 鼀꾀 㡰 �鼀꾀 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 矄�矄 ᨨ盐䁸 ᲼҈黨黨䰘㜠҈㝐├桌 㡰 矄�矄 ᆠᨨ � � 矄�ᆠ矄鼀�ᆠᨨ 盐ᆠᨨ矄 ᆠ矄 犨� � ᆠ矄ᨨ 鼀盐 㡰 ᨨ� �盐和�犨� � �鼀盐��矄��p㜠泐 矄鼀�ᆠᨨ 盐ᆠᨨ矄 ᆠ㡰 鼀ᨨ�泐ᆠ�矄� n㜠泐矄鼀�ᆠᨨ 盐ᆠᨨ矄 ᨨ矄 㡰 꾀p㜠n盐 ᆠ�ᨨ ᆠ ᆠ矄矄鼀�ᆠᨨ 盐ᆠᨨ �ᨨ 

out-put +



҈





0

��盐矄 ᨨ犨矄ᆠ�ᆠ盐�� 犨 �ᆠ  �  �ᆠ �ᨨ 矄 盐矄 쟼ᆠ  �ᨨ  矄 ᨨ犨 矄�矄 ᆠᨨ W � � � ᆠ├犨 矄�矄 ᆠ 矄�矄ᨨ矄 ҈㦨 㦨 㦨�W.泐 ᨨ��矄 ᆠ盐  ᨨ盐�  �矄 ᲼㝐� 졠 � 꾀�҈桌



㡰 ᨨ 㡰  ᆠ㡰  㡰   꾀 盐㜠犨ᆠ� �ᆠ�ᆠ盐�ᨨ �犨�  ᨨ盐㜠盐�矄矄 ᨨ犨

�  ��盐 ᆠᨨ �盐�ᨨ  矄㡰 ᨨ鼀  �ᨨ ҈�矄 㡰 ᲼҈黨黨㜠㝐├矄桌 V





100 W

6V

B

C D

0 t 㡰 ᔴ out-put 㡰 꾀ᔴ ᆠ㡰  㡰 꾀ᔴ ҈ ᨨ��泐ᨨ ᆠᨨ 矄ᨨ ᨨ盐 �  ᆠᨨ 盐ᆠ�ᨨ

 ᨨ  � � 矄�ᆠ矄鼀�ᆠᨨ 盐ᆠᨨ � �鼀盐 ᲼҈黨黨�和桌 㡰 � ᆠ矄矄 ᨨ  �泐犨� � ᆠ矄� � � 㡰 ᆠ矄矄 ᨨ  �泐犨� � ᆠ矄� � � ᆠ㡰 ᆠ矄矄犨� � ᆠ矄� �鼀盐 㡰 �矄�   ᨨ  鼀盐   � 3

Numeric Answer

 ᨨ   �ᨨ 矄盐矄 �  ᆠ�ᆠ盐�矄 ᨨ犨 矄矄盐鼀 ᨨ  �     ���� 矄�矄 ᆠ 犨    矄  ᨨ犨 �矄 盐�� ᨨ �� ᆠ  �ᨨ �矄䰘 ᨨ   � 盐 ᨨ�矄 矄 ᨨ犨  �    ��盐   ᨨ� �

ᨨ矄㡰ᨨ� 꾀�矄힘힘힘힘힘힘힘힘 ᲼㝐� 黨 ᔼ桌

 ᆠ�ᆠ盐�矄 ᨨ犨 ᨨ犨�矄犨ᨨ├� �矄 ᆠ�盐 ᨨ�矄ᨨ盐ᆠ␔  ҈�矄盐矄 矄� 盐  ᨨ犨 �矄矄�  �  鼀␔㡰�  ᆠ  �ᨨ  �矄錐 ᆠᨨ 矄� � �ᨨ   �ᨨ 矄�  �ᆠ㡰힘힘힘힘힘 ᲼㝐� 黨 ᔼᔼ桌

WWW.JEEBOOKS.IN

EBD_8341 P-306

Physics



҈

ᔼ



6 4  �



䰘

ᔼ �矄 㜠 盐 ᆠ�ᨨ    ᨨ犨ᨨ  ᨨ矄�矄 ᨨ鼀  n��ᨨ ᨨ p��ᨨ  ᲼҈黨黨㜠҈㝐├桌 ᨨ �� ᆠ�ᆠ盐�矄 ᨨ犨 �  ��ᨨᆠ矄 盐犨ᆠ� �  ᆠ� 盐矄 ᨨ盐 ᆠᨨ

ᆠ ᆠᨨ矄矄      ᆠ ᨨ盐盐 犨ᨨ盐   ᆠᨨ矄矄   ᲼҈黨黨҈㜠҈㝐├桌 







�矄� �ᨨ p㜠n盐 ᆠ�ᨨ ᨨ 矄 �� 矄�矄 ᆠᨨ ᆠ盐  ᨨ犨ᆠᨨ矄矄 盐 ᆠ�ᨨ  �矄� ��矄ᨨ�  泐ᆠᨨ

ᆠ� � p㜠矄� ᨨ 鼀� ᨨ   泐 ᲼҈黨黨㜠㝐├矄᲼ ᔼ   ᨨ犨 �矄 �鼀 ᨨ p㜠n盐 ᆠ�ᨨ ᆠ� �  p �矄ᆠᨨ

ᆠ ᨨ 鼀� ᨨ  泐    �ᆠ�ᨨ ᨨ  ᆠ盐 �矄 ᨨ鼀ᨨ�

 ᆠ� � ᲼҈黨㜠㝐├矄桌 5



Fill in the Blanks

True / False

ᨨ �ᨨ  ��ᨨ ᨨ �矄 ᨨ ᆠ盐 Ia犨�    ᨨ ᨨ�Va犨ᨨ �  ᆠ ᨨ 鼀盐矄T҈  T �矄矄 ᨨ犨 �    ��盐 鼀盐 T  �矄 �  T҈ ᲼҈黨㜠㝐├矄桌

MCQs with One or More than One Correct Answer

黨 ᔼ p㜠n盐 ᆠ�ᨨ  �ᨨ  ᨨᆠᨨ

ᆠ ᨨ 泐ᆠ�ᆠ盐� ᲼҈黨黨和㜠㝐├矄桌 㡰  ᨨ ��矄 矄鼀泐犨  㡰  p㜠泐矄� �矄 �� ᨨ �   n㜠 泐 矄�  ᆠ㡰  �矄 ᆠ�ᆠ �  盐 ᆠ�ᨨ  �ᆠ  ᨨ鼀   n㜠泐矄� ᨨ p㜠泐矄�  㡰  �矄 ᆠ�ᆠ �  盐 ᆠ�ᨨ  �ᆠ  ᨨ鼀  p㜠泐矄� ᨨ n㜠泐矄�   ᨨ矄ᆠ �ᆠ�矄�

᲼҈黨黨㜠㝐├矄桌 㡰 � � 矄�ᆠ矄鼀�ᆠᨨ 盐ᆠᨨ矄 㡰 �ᨨ �ᆠ矄ᨨ� 矄 ᆠ㡰 p㜠泐 矄鼀�ᆠᨨ 盐ᆠᨨ矄 㡰 鼀矄 ҈ 犨ᨨ�  �ᆠp㜠n盐 ᆠ�ᨨ 矄鼀泐ᆠᨨ

ᆠ � 矄�矄 犨� 泐�  犨泐矄 �� ᨨ � ᨨ矄ᆠᨨ矄矄  犨ᨨpn盐 ᆠ�ᨨ 矄⼄盐� ᲼҈黨黨㜠㝐├矄桌  �鼀盐�泐ᨨ鼀矄犨� 犨 �ᆠ  盐矄��ᆠᨨ  矄 ᨨ盐  ᨨ ᨨ鼀├ p㜠泐矄鼀�ᆠᨨ 盐ᆠᨨ ᨨ矄ᨨ ᲼҈黨㜠㝐├矄桌 㡰  ᨨ矄 ᨨ盐矄 㡰 ᨨᨨ

ᆠ㡰  �鼀ᨨ 泐 㡰 盐鼀� �盐鼀  和ᆠ ᆠᨨᆠ矄鼀  ᨨ鼀  ᨨᨨ犨� � 㡰 꾀 �ᨨ ᆠ 盐矄 矄ᆠ� �᲼҈黨㜠㝐├矄桌 㡰 꾀�ᨨ ᆠ

ᨨ盐矄 矄ᆠ� � ᆠ㡰 ᆠ盐 �  �ᨨ �矄犨泐矄ᨨᨨ�ᨨ ᨨ  � ᨨ� 㡰 � ᨨ�ᨨ ᨨ  ᔼᆠ ᆠ�矄�ᆠᨨ �ᨨ  �矄盐矄  ᨨ鼀� �ᆠ�ᨨ 犨� ᨨ盐 �矄ᨨ�ᨨ

Topic-2 : Junction Transistor 1 ҈

MCQs with One Correct Answer

 矄  ᆠ ᆠ�矄�ᆠᆠ盐ᨨ  矄�矄ᨨ � � � 盐 ᨨ盐盐矄�矄 ᆠ҈W ҈├W矄ᆠ�泐 �矄矄 ᨨ犨 �   ��盐 ᨨ� ᨨ犨��  矄ᆠ�泐 ᲼㝐� ҈꾀҈黨ᔼ桌





㡰 �맔҈�맔҈ 㡰 �맔҈�맔҈  � ᆠ㡰 �맔҈  �맔҈ 㡰 �맔҈�맔҈ 꾀    矄�矄ᨨᨨ矄矄ᆠᨨ鼀鼀ᨨ 鼀�鼀� � 犨� ᨨ犨�� ᨨ   � 盐ᆠ�ᆠ盐�矄�矄 ᆠ�矄 ҈W   ᨨ盐盐ᨨ 矄�矄 ᆠ�矄҈├W ᆠᨨ鼀鼀ᨨ

鼀�ᆠ盐 �� b�矄 ᲼㝐� ҈꾀҈黨ᔼ桌 㡰 ҈ 㡰  ᆠ㡰 맔҈ 㡰 ҈ 꾀  矄�矄ᨨ�矄盐矄 � ᆠᨨ鼀鼀ᨨ 鼀�ᆠᨨ ��盐�ᨨ

矄 鼀� �犨� ҈├!ᨨ 矄�矄 ᆠ和�� ᨨ� ᨨ ҈鼀�矄� ᆠᨨ矄矄 矄㜠鼀� �矄ᨨ 盐ᆠ矄 鼀꾀ᆠ  ��  ᆠᨨᆠᨨᆠ盐  ҈�꾀ᆠ  ��

 矄ᆠ盐 ᨨ  鼀� � � 盐矄�矄 ᆠ ᲼㝐� 黨꾀�҈黨ᔼ桌 ᨨ���  㡰 ├W҈� 㡰 䰘├W ᆠ㡰 䰘├W 㡰 ├W

WWW.JEEBOOKS.IN

P-307

Semiconductor Electronics : Materials, Devices and Simple Circuits

4.

A common emitter amplifier circuit, built using an npn transistor, is shown in the figure. Its dc current gain is 250, RC = 1 k &! and VCC = 10V. What is the minimum base current for VCE to reach saturation ? [Main 8 Apr. 2019 II]

(a)

1 -1 (W ) ri 0.01

(b)

1 -1 (W ) ri 0.01

0

0

(c)

0.6 VBE (V)

1 -1 (W ) ri

1

(d)

0.6 1 VBE (V)

1 -1 (W ) ri 0.1

10

(b) 100 mA (d) 10 mA

0

IC C

RB B

5.

6.

v1 ~

VBB

RC

E

In the figure, given that VBB supply can vary from 0 to 5.0 V, VCC = 5 V, bdc = 200, RB = 100 kW, RC = 1 KW and VBE = 1.0 V. The minimum base current and the input voltage at which the transistor will go to saturation, will be, respectively : [Main 12 Jan. 2019 II] (a) 25 µA and 3.5 V (b) 20 µA and 3.5 V (c) 25 µA and 2.8 V (d) 20 µA and 2.8 V In a common emitter configuration with suitable bias, it is given than RL is the load resistance and RBE is small signal dynamic resistance (input side). Then, voltage gain, current gain and power gain are given, respectively, by: (b is current gain, IB, IC, IE are respectively base, collector and emitter currents:) [Main Online April 15, 2018] (a)

b

RL DI E 2 RL , ,b RBE DI B RBE

R

DI

R

2 L 2 L C (c) b R , DI , b R BE E BE

7.

8.

DI

R

R

2 C L L (b) b R , DI , b R BE B BE

R

DI

R

2 L L C (d) b R , DI , b R BE B BE

In a common emitter amplifier circuit using an n-p-n transistor, the phase difference between the input and the output voltages will be : [Main Online April 2, 2017] (a) 135° (b) 180° (c) 45° (d) 90° For a common emitter configuration, if a and b have their usual meanings, the incorrect relationship between a and b is : [Main 2016] b (a) a= 1 +b

(b) a=

b2 1 +b2

1 1 = +1 (d) All of these a b A realistic graph depicting the variation of the reciprocal of input resistance in an input characteristics measurement in a common emitter transistor configuration is : [Main Online April 10, 2016]

(c)

9.

~ v0

VCC

IE

0.6 VBE (V)

1

0

0.6 VBE (V)

1

10. An n-p-n transistor has three leads A, B and C. Connecting B and C by moist fingers, A to the positive lead of an ammeter, and C to the negative lead of the ammeter, one finds large deflection. Then, A, B and C refer respectively to: [Main Online April 9, 2014] (a) Emitter, base and collector (b) Base, emitter and collector (c) Base, collector and emitter (d) Collector, emitter and base. 11. For a given plate voltage, the plate current in a triode valve is maximum when the potential of [1985 - 2 Marks] (a) the grid is positive and plate is negative (b) the grid is zero and plate is positive (c) the grid is negative and plate is positive (d) the grid is positive and plate is positive 12. The plate resistance of a triode is 3 × 103 ohms and its mutual conductance is 1.5 × 10 –3 amp/volt. The amplification factor of the triode is [1981- 2 - 3 Marks] (a) 5 × 10–5 (b) 4.5 (c) 45 (d) 2 × 10 5 3

Numeric Answer

13. The output characteristics of a transistor is shown in the figure. When VCE is 10 V and IC = 4.0 mA, then value of bac is ______. [Main Sep. 06, 2020 (II)] (IB ) 60 mA 50 mA 40 mA 30 mA 20 mA 10 mA

8

(IC) in mA

(a) 40 mA (c) 7 mA

6 4 2 2

6

4

6 8 10 12 14 (VCE) in volts

MCQs with One or More than One Correct Answer

14. A transistor is used in the common emitter mode as an amplifier. Then [1998S - 2 Marks] (a) the base-emitter junction is forward-biased (b) the base-emitter junction is reverse-biased (c) the input signal is connected in series with the voltage applied to bias the base-emitter junction (d) the input signal is connected in series with the voltage applied to bias the base-collector junction

WWW.JEEBOOKS.IN

EBD_8341 P-308

҈�

Physics

� 矄�  ��ᨨ ᨨ ᨨ盐� 矄꾀�� ᨨ�ᨨ ҈ ᨨ  ᨨ ᆠ盐 ᔼ � 鼀��鼀矄㡰�矄�� � 鼀矄 ᨨ ᨨ� � ᨨ矄㡰泐 ��ᆠ�ᨨ  ᔼ㦨҈�䰘� ᨨ�� ᨨ�ᨨ ᨨ矄 ᆠ盐  ᨨ ᨨ� ᨨ ᨨ矄�矄�鼀��鼀鼀�  矄�矄 ᆠ rp㡰 矄ᆠᨨ 盐ᆠ ᆠ gm㡰  鼀� �ᆠ�ᨨ  ᆠᨨ Ҙ㡰 ᨨ �ᨨ  ᲼҈黨䰘㜠䰘㝐├矄桌

ᔼ  n㜠p㜠n 矄�矄ᨨᆠ�ᆠ盐� ᆠᨨᆠᨨᆠ盐 �矄҈ 鼀꾀ᔼ 黨奠ᨨ  ᆠᨨ 矄鼀� ᆠ  ᆠᨨᆠᨨ 㡰  鼀�ᆠ盐 犨�黨鼀꾀 ᲼҈黨黨㜠㝐├矄桌 㡰  矄ᆠ盐 犨�҈鼀꾀 ᆠ㡰  鼀�ᆠ盐 犨�҈҈鼀꾀 㡰  矄ᆠ盐 犨�҈鼀꾀 10 Subjective Problems

҈

꾀�ᨨ  矄ᆠ ᆠ�矄�ᆠ矄�   ᨨ鼀ᨨ 

Topic-3 : Digital Electronics and Logic Gates 1 ҈



MCQs with One Correct Answer

ᔼ  � 泐   ᆠᨨᆠ ᨨ盐盐 矄��  Ӹ �    ��

ᆠᨨ鼀� �ᨨ ᨨ �矄 矄矄 ᨨ犨 㡰 ᨨ �� � 盐矄꾀   ᲼㝐� 和 ᔼ㡰桌  Ӹ 꾀

A





҈

҈�



Z

B

꾀

�

ᔼ   ᨨᨨ犨� � ����ᆠ�ᆠ盐�犨 犨� ᨨ盐盐 �Z犨   � 盐 A, B㡰 ҈㡰 㡰 ҈҈㡰 ҈㡰 [Main Sep.02, 2020 (II)]

㡰 ҈ 㡰 ҈҈҈ ᆠ㡰҈҈҈ 㡰 ҈ ᨨᨨ �ᨨ  ᨨ盐盐矄�㜠Y ᨨ  ᨨᨨ犨� � ᆠ�ᆠ盐��矄 ᲼㝐�  ᔼ桌



㡰 

�

㡰

㡰 A + B 㡰 A졔B ᆠ㡰AB 㡰 AB ᔼ  �� ᆠ�ᆠ盐�盐ᨨ Y�矄 ᲼㝐�  ᔼᔼ桌



ᆠ㡰 �



҈ ҈� 



 㡰 ᔼ  � 泐 ᨨ�ᨨ  ᨨ鼀 泐 ᆠ�ᆠ盐��� ᨨ犨 ᲼㝐� 和 ᔼᔼ㡰桌







㡰  㡰 ᨨ��矄犨  ҈ ᆠ㡰 犨� ᨨ ᆠ盐 㡰 ҈ ␔ �ᆠ ᨨ   ᨨᨨ犨� ���矄矄�ᨨ�ᨨ 䁸 ᲼㝐� 䰘 ᔼ桌 㡰

㡰

ᆠ㡰





㡰 꾀 㡰 졠

ᆠ㡰 꾀

㡰 졠

WWW.JEEBOOKS.IN

P-309

Semiconductor Electronics : Materials, Devices and Simple Circuits

䰘

盐  ᨨ ᆠ�ᆠ盐��� �   ���矄 ᲼㝐� 黨꾀�҈黨ᔼ桌

҈҈

盐  ᨨ �� ᆠ�ᆠ盐�犨� ᲼㝐� 졠 � 꾀�҈�҈桌 x

z é꾀  Ӹ ù é꾀  Ӹ ù é꾀  Ӹ ù ê  ҈ú ê  ҈ú ê  ҈ú ê ú ê ú ê ú ê ҈ ҈ú ê ҈ ú ê ҈ ҈ú ê ú ê ú ê 㡰 ҈  ҈  㡰 ҈    ᆠ㡰 ҈   ú 㡰 ê ú ê ú ê ú êë ҈ ҈ ҈ úû êë ҈ ҈  úû êë ҈ ҈  úû



黨

é꾀  Ӹ ù ê  ú ê ú ê ҈ ú ê ú ê҈  ҈ú êë ҈ ҈ ҈ úû

y

㡰

ᨨ��ᆠ�⼄盐� ᨨ �� ᨨ��ᆠᆠ�ᆠ盐��矄 ᲼㝐� 黨꾀҈黨ᔼᔼ桌

㡰 꾀 㡰 졠 ᆠ㡰 졠 㡰 꾀

ᨨ盐盐ᨨ  �� ᨨ��ᆠᆠ� ᆠ盐��矄 ᲼㝐� ҈ ҈黨ᔼ桌 꾀

  ҈ ҈

泐  ҈  ҈

҈ ҈ ҈ 

㡰

  ҈ ҈

泐  ҈  ҈

    ᆠ㡰   ҈ ҈ ҈

泐  ҈  ҈

҈ ҈  㡰 ҈ ҈

  ҈ ҈

泐  ҈  ҈

 ҈ ҈ ҈

҈ ᔼ ᆠ � 盐矄ᨨ�  �矄�矄ᨨ盐盐  矄   ᨨᨨ犨� ��鼀�  ��矄 ᲼㝐� ҈桌   ᆠ 㡰 졠 㡰 꾀 ᆠ㡰 졠

㡰 꾀 ҈ ᨨ� ᨨ盐盐ᨨ ҈ ᨨ鼀 ᆠ�ᆠ盐�矄 ᨨ犨 �  ��盐  � 盐鼀盐矄 ᲼㝐� 졠 � 꾀�҈҈桌

Ӹ

 



Ӹ

㡰 꾀 + 꾀 㡰 꾀 + 꾀 ᆠ㡰 꾀 㡰 꾀 ҈ ᨨ � ᨨ盐盐 �҈  ᨨ  ��  ᨨ��ᆠ � ᆠ�ᆠ盐�   � 盐 盐矄 鼀盐矄  ᲼㝐� ҈ ҈黨ᔼ桌

㡰 㦨Ӹ㦨҈ ᆠ㡰 㦨҈Ӹ㦨



㡰 㦨㦨ᆠ㦨҈ 㡰 㦨҈㦨ᆠ㦨 ᆠ㡰 㦨҈㦨ᆠ㦨҈ 㡰 㦨㦨҈ᆠ㦨 ҈ ᔼ  � 泐 � 鼀ᆠ 꾀Ӹ� ᆠ├ᨨᆠ ᆠ├ ᲼㝐� 졠 � 꾀�黨҈桌

㡰 㦨҈Ӹ㦨҈ 㡰 㦨Ӹ㦨

꾀 

꾀

㡰 㡰 ᆠ㡰 㡰

꾀 꾀㦨҈㦨҈Ӹ㦨҈㡰 졠  꾀㦨҈㦨҈Ӹ㦨㡰 졠  꾀㦨҈㦨҈Ӹ㦨҈㡰 졠  꾀㦨㦨Ӹ㦨㡰

Ӹ

Answer Key Topic-1 : Solid Semiconductors and P-N Junction Diode ҈ ҈҈ ҈ ҈ 䰘 ҈

㡰  ᆠ㡰  㡰 ҈ 㡰 ҈ ᆠ㡰  㡰  㡰  ҈㡰  졔 㡰p㜠矄� n㜠矄� 㡰 㡰   㡰 

ᆠ㡰 㡰 㡰 㡰

盐 㡰

 ҈   黨

ᆠ㡰 � ᆠ㡰 ҈� 㡰 � 矄㡰 ᆠ㡰 

㡰 㡰 㡰

 ҈  �

ᆠ㡰 䰘 ᆠ㡰 ᆠ㡰 ҈䰘 㡰 㡰 䰘 㡰 錐꾀ᔴ㡰

 ҈  

㡰 黨 㡰 ҈ 㡰 㡰 ҈黨 ᆠ㡰  㡰 ᆠ㡰 黨 㡰  㡰 矄 ��㡰

ᆠ㡰

Topic-2 : Junction Transistor ҈ ᨨ 盐矄㡰  㡰 ҈҈ 㡰 ҈ 㡰

 㡰 ҈ ҈�㡰

 㡰 � 㡰 ҈ ᆠ㡰 ҈� ᆠ㡰

 㡰

䰘 㡰

 㡰

黨 ᆠ㡰

҈ ᆠ㡰

 㡰

黨 ᆠ㡰

҈ ᆠ㡰

Topic-3 : Digital Electronics and Logic Gates ҈ 㡰 ҈҈ ᆠ㡰

 ᆠ㡰 ҈ 㡰

 㡰 ҈ ᆠ㡰

 㡰 ҈ 㡰

� 㡰

 㡰

䰘 ᆠ㡰

WWW.JEEBOOKS.IN

EBD_8341 P-310

Physics

Communication Systems

29

Topic-1 : Communication Systems 1 ҈

MCQs with One Correct Answer

�

꾀  鼀�盐  鼀ᨨ 盐  犨 �矄 矄   泐    矄矄�ᨨ  vm = � ҈ +  ᆠᨨ矄 t 㡰 矄� ҈҈´ ҈ t 㡰 ᨨ矄

鼀� �鼀盐鼀 鼀 �鼀盐鼀鼀�盐 矄ᨨ  鼀�盐  鼀ᨨ 盐 犨矄ᆠ�泐 [Main Sep.02, 2020 (I)] �    �  㡰       㡰 � ᆠ㡰 � ᔼ  鼀�盐 鼀ᨨ 盐ᨨᆠ�ᆠ盐� ᆠ�犨�矄��

泐ᔴ t㡰㦨矄�  pt㡰犨 �鼀ᨨ 盐� �矄�� �矄��

泐m t㡰㦨矄�  pt㡰 盐矄ᨨ 鼀ᨨ 盐�ᨨ �   ᨨ犨矄�   ⼄盐 ᆠ泐 ᲼㝐� ҈꾀�҈黨 ᔼᔼ㡰桌 㡰 � ҈├ 㡰  ҈├ ᆠ㡰  黨├ 㡰 � 黨├ 꾀 鼀矄矄� 矄��  ᨨ  ⼄盐 ᆠ泐 ҈ 㝐    ├ ᨨ�҈�矄盐矄 ᨨ ᆠ盐鼀�盐 鼀ᨨ 盐�ᨨ ᨨ

ᆠ�犨ᨨ  ⼄盐 ᆠ泐෌  ├ᨨ�  鼀ᨨ 盐�ᨨ �    �  ᆠ犨  犨ᨨ 矄�   ⼄盐 ᆠ�矄 ᲼㝐� ҈꾀�҈黨 ᔼᔼ㡰桌  㡰 錐҈맔҈  㡰 錐맔҈  ᆠ㡰 �錐맔҈  㡰 �錐҈맔҈ 꾀矄�� 꾀ᆠᨨ矄w�矄 矄鼀� 盐矄� �v矄� wĀ矄ᆠ� 犨 ᆠᨨᆠ鼀�盐 鼀ᨨ 盐  꾀㝐㡰矄�� �矄 ᲼㝐� 黨꾀�҈黨 ᔼ㡰桌



㡰







㡰 v矄� wĀ t + 꾀 矄� ( w  w ) t + 꾀 矄� ( w  + w ) t 뾼   㡰 v矄� ᲼w ҈졔҈꾀矄� w㡰桌 ᆠ㡰 v矄� w졔꾀ᆠᨨ矄w 㡰 v졔꾀㡰ᆠᨨ矄w矄� wĀ

䰘



 泐矄�ᆠ矄� 矄ᨨ   矄鼀� ᆠ� 

 � ᆠᨨ鼀鼀盐 �ᆠ�ᨨ 矄泐矄鼀᲼㝐� 黨꾀�҈黨 ᔼᔼ㡰桌 㡰 �   ᨨ ᨨ ᆠ� 鼀ᨨ 盐�ᨨ  ⼄盐 ᆠ泐 㡰 � 矄泐ᨨᨨ�ᨨ ᨨᆠ� ⼄盐 ᆠ泐 ᆠ㡰 � 矄泐ᨨᨨ�ᨨ ᨨ鼀ᨨ 盐�ᨨ  ⼄盐 ᆠ泐 㡰 ᨨᨨ�ᨨ ᨨᆠ� ⼄盐 ᆠ泐

犨 � ᨨ  ᆠ�犨矄� 鼀ᨨ  ᨨ�ᆠ �ᆠᨨ鼀鼀盐 �ᆠ�ᨨ  犨ᨨ├�矄ᆠᨨ矄ᨨ ᲼㝐� 꾀�҈黨 ᔼ㡰桌 㡰  鼀 㡰 ҈� 鼀 ᆠ㡰  鼀 㡰 黨 鼀 ᔼ � ᨨ 矄�� �ᨨᆠᨨ鼀鼀盐 �ᆠ�ᨨ  �矄 ᆠᨨ ᨨ盐 � ├鼀 �矄├犨     矄鼀�� �   ᆠ�� �  

矄ᔼ   �� ᨨ  ᆠ�� � 

�矄䰘鼀     鼀� �鼀盐鼀 �� ᨨ     矄鼀�� �  

 矄 ᨨ盐  ᲼㝐� 꾀�҈黨 ᔼᔼ㡰桌  �盐矄ᨨ  쟼 㦨맔҈鼀㡰 㡰 鼀 㡰 �҈鼀 ᆠ㡰 鼀 㡰 鼀 꾀҈ᆠ�犨�矄鼀 ᨨ泐犨 ҈ 泐鼀ᨨ 盐� �矄�� ␔ �矄 鼀ᨨ 盐�ᨨ �  䁸

᲼㝐� ҈ ҈黨 ᔼ㡰桌 ᆠ㡰  㡰  㡰  㡰 � 黨

ᨨ ᨨ盐 ᆠᨨ� � �ᨨ   矄鼀��ᨨ ᨨ犨 �矄 �� 矄 ᨨ盐 鼀盐�� 泐 ᲼㝐� ҈ ҈黨 ᔼᔼ㡰桌 ҈ 㡰 㡰  㡰  ᆠ㡰   ҈ 꾀 鼀�盐 鼀ᨨ 盐 矄�� �矄�� 泐 㡰㦨҈᲼҈졔 ᆠᨨ矄 맔҈㡰桌矄� ��맔҈�㡰�矄� 矄ᆠᨨ 矄

矄�   ⼄盐 ᆠ�矄 � ├ 㡰᲼෌� p㦨⏌䰘桌 ᲼㝐� ҈҈ ҈黨 ᔼᔼ㡰桌 㡰 ҈䰘� ҈䰘҈� 㡰 ҈䰘� ҈䰘҈� ᆠ㡰 黨� �䰘� 㡰 黨� �䰘�

WWW.JEEBOOKS.IN

P-311

Communication Systems

҈҈

꾀 鼀�盐 鼀ᨨ 盐 矄�� �矄ᨨ ᨨ犨 ҈ 

 㡰

  m矄 ҈m矄 ␔ �ᆠ  ᨨ  ᨨ    ᨨᨨ犨� � 矄 矄ᆠ�矄   ᨨ 矄�� 䁸 ᲼㝐� ҈҈ ҈黨 ᔼᔼ㡰桌 㡰 黨졔矄�  �p맔҈�㡰㡰矄�  p맔҈㡰 㡰

҈

҈졔黨矄�  p맔҈㡰㡰矄�  �p맔҈�㡰

ᆠ㡰 黨졔矄�  p맔҈㡰㡰矄�  �p맔҈�㡰 㡰 黨졔矄�  p맔҈㡰㡰矄�  �p맔҈�㡰 꾀  矄鼀�矄矄�ᨨ ᨨ犨 矄 �� ᨨ ҈鼀   ��  ᨨ   ᆠ�� �  

 �矄  鼀 ␔  �矄   鼀 �鼀盐鼀 �矄 ᆠ盐ᨨ犨 �ᆠ 矄�� 矄ᆠ ᨨ ᆠ矄 ᨨ鼀 �矄ᨨ犨� 졠和 � ᨨ 和�� 㡰鼀ᨨ 䁸 ෌�   �盐矄ᨨ  㦨맔҈鼀㡰 ᲼㝐� ҈ ҈黨 ᔼ㡰桌 㡰 �├鼀

҈

҈

҈�

҈

҈䰘

㡰 ├鼀

ᆠ㡰 ├鼀

㡰 ├鼀

鼀ᨨ 盐�ᨨ  ⼄盐 ᆠ泐ᨨ  꾀㝐 �ᨨ矄�ᨨ �矄� ├ 犨 �ᆠ �矄҈奠ᨨ  ᆠ�犨ᔼ  ᨨ 꾀㝐矄㜠 �ᨨ ᨨᆠ 矄泐ᨨ盐 ᨨ�ᆠ 矄犨 ᨨ ᆠ矄 ⼄盐 ᆠ泐 犨�泐ᨨ盐ᨨ䁸 ᲼㝐� ҈ ҈黨 ᔼ㡰桌 㡰 䰘�├ 㡰 黨├ ᆠ㡰 �├ 㡰 ├ ᔼ ᆠᨨ鼀鼀盐 �ᆠ�ᨨ 矄泐矄鼀ᨨ� �犨 � 

鼀ᨨ 泐ᨨ ᆠ ᨨ 矄ᨨ盐ᆠ ⼄盐 ᆠ泐�矄�矄 矄��  犨�    盐鼀ᨨ ᆠ 

矄ᆠᆠᨨ鼀ᨨ  ᨨ 矄鼀�� � 矄�� 矄ᨨ  犨�  㝐  ├ ᨨᆠ�泐ᨨ �� ᆠ㦨맔҈鼀⏌矄 㦨맔҈㜠矄㡰 ᲼㝐� 黨 ҈黨 ᔼᔼ㡰桌 㡰 䰘�맔҈ 㡰 맔҈ ᆠ㡰 �맔҈� 㡰 䰘맔҈� 꾀 ᨨ �ᆠᆠᨨ鼀鼀盐 �ᆠ�ᨨ 矄�ᆠ�矄犨ᨨ├� �ᆠ� ⼄盐 ᆠ泐 ᨨ  ҈ ෌  졠 泐҈奠 ᨨ  � �矄 盐��   ᨨ  矄鼀�矄矄�ᨨ  ᨨ犨鼀 泐 ᨨ �ᆠ ᆠ 

矄ᆠ    矄鼀�  矄�鼀盐 ᨨ盐矄泐� ᆠ  ᆠ 

 ⼄盐�矄   犨�  ᨨ �├ 䁸 ᲼㝐� ҈桌 㡰 맔҈ 㡰 맔҈ ᆠ㡰 맔҈� 㡰 맔҈ 꾀ᆠ�犨ᨨ ├ᨨ�҈�矄盐矄  ᨨ 矄鼀�� � 鼀矄矄�矄��  ├ᨨ�ᨨ 鼀ᨨ 盐� �矄��  �� ᨨᆠ �鼀ᨨ 盐�ᨨ �  ᨨ 奠犨� ᲼㝐� ҈桌 㡰 ҈҈ 㡰 䰘 ᆠ㡰  㡰 

 盐鼀ᨨ 鼀�盐 鼀ᨨ 盐 ᨨ ᆠ矄矄�ᨨ 矄  ᆠ ᆠᆠᨨ鼀鼀ᨨ  � ├  犨�   ᨨ  �� 矄鼀ᨨ 盐� � ⼄盐 ᆠ泐҈�├ 犨� ᲼㝐� 졠 � 꾀�҈�҈桌 㡰  㡰 ҈ ᆠ㡰  㡰 ҈�

҈ ᆠ� ⼄盐 ᆠ泐ᨨ  矄鼀��矄ᨨ�  泐  ├ᆠ�ᆠ盐�ᨨ ᆠᨨ�ᨨ � 盐ᆠ ᆠ黨m ᆠᆠ� ᆠ ᨨ � ᔼ�矄鼀ᨨ 盐 泐 盐 �ᨨ矄�� ᨨ ҈├   ⼄盐 ᆠ泐 �ᨨᆠᆠ盐� 泐 矄�  矄�矄 ᲼㝐� 졠 � 꾀�҈�҈桌 㡰 ҈├ ├ 㡰 ├ 䰘�├ ᆠ㡰 ├ ├ 㡰 ҈├ ҈黨├ ҈黨 ᔼ 鼀�盐 鼀ᨨ 盐�ᨨ 矄� 盐矄ᨨ� ᆠ� ⼄盐 ᆠ泐盐矄 �矄  ᨨ  泐 ωc   矄��  ⼄盐 ᆠ泐�矄  ᨨ 泐

ωm   犨�   Dωm 㡰ᨨ  矄�� �矄矄盐ᆠ   Dω m  ωc ␔ �ᆠ ᨨ   ᨨᨨ犨� � ⼄盐 ᆠ�矄�矄 ᨨᆠᨨ �  �  鼀ᨨ 盐 犨䁸 ᲼㝐� ҈䰘桌 㡰 ω m + ω c 㡰 ω c - ω m ᆠ㡰 ω m 㡰 ωc  꾀 矄��  �矄ᨨ 矄鼀�   ᨨ盐�  犨ᨨ 犨㜠  � l盐矄� ��  

  � ҈ᨨ   㜠 

  ᆠ�ᨨ犨 �  犨��� 㜠 矄ᆠ�泐矄 ⧤�矄ᆠᨨ 矄 ᨨ ᨨᨨ�ᨨ �泐㡰 ᲼㝐� 졠 � 꾀�黨҈䰘桌 

l æ҈ö  㦨 ⧤ ç ÷    èlø

æ҈ö 㡰 l,  㦨⧤ ç ÷ èlø

㡰

 l ҈ ᆠ㡰  㦨 ⧤ æç ö÷ ҈ èlø

l æ ҈ ö 㡰  㦨 ⧤ ç ÷ �   èlø

҈

҈ 꾀矄�� ᨨ  ⼄盐 ᆠ泐├  ├ᨨ�ᨨ �ᨨ�矄 盐矄 ᨨ鼀ᨨ 盐ᆠ�犨ᨨ  ⼄盐 ᆠ泐҈㝐  ├ᨨ��ᨨ矄ᔴ ᨨᨨ矄 ᆠᨨᆠ矄鼀  ᲼㝐� 졠 � 꾀�҈䰘桌 㡰 㝐ᨨ 盐�ᨨ  �  㦨�矄�  ⼄盐 ᆠ泐 矄 ҈├  ҈├ 㡰 㝐ᨨ 盐�ᨨ  �  㦨�矄�  ⼄盐 ᆠ泐 矄 ҈├  ҈├ ᆠ㡰 㝐ᨨ 盐�ᨨ �  㦨矄�  ⼄盐 ᆠ泐 矄 ҈҈├  ҈├ 㡰 㝐ᨨ 盐�ᨨ �  㦨矄�  ⼄盐 ᆠ泐 矄 ҈├  ҈҈├  ᔴ ᨨᨨ矄 ᆠᨨᆠ矄鼀  ᲼㝐� ҈桌 㡰 ᔼ  ⼄盐 ᆠ泐鼀ᨨ 盐�ᨨ  鼀�盐 ᨨ   �� ⼄盐 ᆠ泐ᆠ�犨�矄鼀 ᨨ泐� ᨨᨨ�ᨨ

ᨨ 鼀�盐 ᨨ  盐 �ᨨ矄��  㡰 ᔼ  ⼄盐 ᆠ泐鼀ᨨ 盐�ᨨ  鼀�盐 ᨨ   �� ⼄盐 ᆠ泐ᆠ�犨�矄鼀 ᨨ泐� ᨨᨨ�ᨨ

ᨨ  ⼄盐 ᆠ泐ᨨ  盐 �ᨨ矄��  ᆠ㡰 ᔼ 鼀�盐 鼀ᨨ 盐�ᨨ  鼀�盐 ᨨ   �� ⼄盐 ᆠ泐ᆠ�犨�矄鼀 ᨨ泐� ᨨᨨ�ᨨ

ᨨ 鼀�盐 ᨨ  盐 �ᨨ矄��  㡰 ᔼ 鼀�盐 鼀ᨨ 盐�ᨨ   ⼄盐 ᆠ泐ᨨ   �� ⼄盐 ᆠ泐ᆠ�犨�矄鼀 ᨨ泐� ᨨᨨ�ᨨ

ᨨ 鼀�盐 ᨨ  盐 �ᨨ矄�� 

WWW.JEEBOOKS.IN

EBD_8341 P-312





�



䰘



黨

Physics

꾀鼀ᨨ 盐 矄�� ᔴ鼀 㡰 矄  ᨨ鼀ᔴ鼀 㡰㦨矄� p 졔҈ ᆠᨨ矄pᆠᨨ矄p㡰 ᆠ� ⼄盐 ᆠ泐 ᆠ  鼀ᨨ 盐� � ⼄盐 ᆠ泐 鼀矄矄� ⼄盐 ᆠ泐㡰 w     鼀ᨨ 盐�ᨨ � � m 矄ᆠ�泐�� 泐 ᲼㝐� 졠 � 꾀�҈҈桌 ҈ 㡰 ᆠ㦨 錐 犨㦨� 錐m 㦨   㡰 ᆠ㦨҈� 錐 犨㦨� 錐m 㦨  ҈ ᆠ㡰 ᆠ㦨҈� 錐 犨㦨 錐m 㦨  ҈ 㡰 ᆠ㦨 錐 犨㦨 錐m 㦨  꾀  盐 �ᨨ矄��  ᆠᨨ 矄�矄矄ᨨ  犨ᨨ �矄� ᆠ 矄ᨨ盐 矄 ᨨ  盐鼀 矄ᆠ 矄�� �   ⼄盐 ᆠ泐 ᨨ  ᨨ 䰘 犨 � ᨨ �矄 ��  ⼄盐 ᆠ泐鼀盐矄�ᆠ矄��  �   ⼄盐 ᆠ泐 ᨨ ҈ ᨨ҈�  �ᨨᨨ  꾀㝐矄��  犨�  ⼄盐� ᨨ矄 ᨨ  矄�� 矄 ᨨ�  ᨨ  꾀㝐 矄��   犨�   ⼄盐�  ᨨ矄 盐矄  盐鼀 矄ᆠ �矄 ᲼㝐� 졠 � 꾀�黨҈桌 㡰  㡰 � ᆠ㡰  㡰  꾀矄�� ᨨ �├  ⼄盐 ᆠ泐�矄鼀�盐 鼀ᨨ 盐 ᨨ  ᆠ�犨ᨨ  ⼄盐 ᆠ泐㝐   ⼄盐 ᆠ�矄ᨨ   矄盐 矄�� �矄⏌ ᲼㝐� ҈�桌 㡰 �├ ├  ҈黨黨�├ 㡰 ├  ҈黨黨�├ ᆠ㡰 㝐 ᨨ 泐 㡰 �├  ҈黨黨�├ ᨨ � � �ᨨ 矄鼀�矄矄�ᨨ �矄ᨨ矄矄�犨    �ᨨ 犨矄 ᆠ  ᨨ鼀 �ᨨ ᨨ矄  ᨨ �矄ᨨ 

  ⼄盐 ᆠ泐ᨨ   �ᨨ犨矄鼀盐矄�   � ᲼㝐� 졠 � 꾀�҈黨҈桌 㡰 㜠҈�㝐 㡰 㜠�㝐 ᆠ㡰 ҈㜠㝐 㡰 ҈�㜠҈�├ ᨨ矄├泐犨ᨨ��ᨨ   �ᨨ犨矄鼀盐矄  ⼄盐 ᆠ泐 �� 犨  ᲼㝐� 졠 � 꾀�҈҈桌 㡰 ҈㝐 ᨨ㝐 㡰 �㝐 ᨨ�㝐 ᆠ㡰 �㝐 ᨨ㝐 㡰 �㝐 ᨨ�㝐 꾀 矄鼀�� � 

 ᨨᨨ ᨨ犨 矄 ��  鼀  �� ᨨ  ᆠ�� � 

�矄�鼀␔ �矄  鼀 �鼀盐鼀 �矄 ᆠ 犨   鼀 ᨨ 矄�矄 ᆠᨨ泐 ᆠᨨ鼀鼀盐 �ᆠ�ᨨ � � ᨨ 矄��  졠和㡰鼀ᨨ 䁸 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 ��├鼀 㡰 ��├鼀 ᆠ㡰 ��├鼀 㡰 ��├鼀 꾀 �ᨨ  ᆠᨨ�矄盐矄 ᨨ ᆠ 鼀�盐 鼀ᨨ 盐 犨ᨨ 奠鼀ᨨ 盐�ᨨ 泐盐矄� �ᆠᨨ  矄ᨨ ᆠᆠ�泐 ��ᆠᨨ  � 犨� ᨨ 矄�矄 ᆠ҈├�ᨨ

ᨨ 鼀 �  鼀 �鼀盐鼀鼀ᨨ 盐  ⼄盐 ᆠ泐犨 �ᆠ ᆠᨨ盐  ᆠ 泐� ᲼㝐� ҈桌  和�� 



҈









㡰 ҈㝐 㡰 ҈├ ᆠ㡰 �҈㝐 㡰 �҈├ ␔ �ᆠ  ᨨ   ᨨᨨ犨� � 鼀ᨨ 盐  矄��  矄   矄

ᨨ�矄㜠ᨨ ᆠ䁸 ᲼㝐� 졠 � 꾀��҈桌 㡰 ᨨ �㜠犨 㡰 和 ᨨ㜠犨 ᆠ㡰 㝐 �盐鼀㜠犨 㡰 꾀鼀�盐 㜠鼀ᨨ 盐 ␔ �ᆠ ᨨ   ᨨᨨ犨� �矄鼀 �矄졠 ᆠᨨᆠ䁸 ᲼㝐� 졠 � 꾀�҈桌 㡰 ෌ᨨ盐 犨 矄�� 矄  鼀ᨨ 矄     矄├泐 犨矄�� 矄 㡰 ᆠ��ᆠ ⼄盐 ᆠ泐ᨨ  �ᨨ ᨨ矄 �ᆠ泐�矄  �� 矄 ⼄盐 ᆠ泐 犨� ᆠ ᆠ├泐  泐犨  ��矄�ᆠ泐� ᆠ�   ᆠ㡰 쟼ᆠᨨ鼀� �ᆠ 犨矄 ᨨ  ⼄盐 ᆠ�矄 ��   

ᨨ盐㝐 ᆠ

ᨨ  �ᨨ ᨨ矄  㡰 和├泐犨矄�� 矄�  ᨨ ᆠ矄 ⼄盐 ᆠ泐 � 矄ᨨ � ��   �   泐�鼀

�矄⼄盐矄�ᨨ  矄和鼀 㜠҈ 和鼀 㜠졠   ᨨ盐ᆠ ᨨ�ᆠ矄��   和鼀 矄ᆠ ᨨᨨ矄 ᨨ   矄 矄ᆠ�矄 犨ᨨ和鼀 矄 和鼀 㜠҈和 ᨨ犨 矄鼀�矄矄�ᨨ �矄ᆠ �  盐ᨨ   ᨨ �    ᆠ�ᨨ  ᨨ    㜠鼀 犨 ᨨ鼀 

ᨨ� �� �  �ᨨ ᨨ矄  和鼀 㜠  ᆠ��  ᨨ 矄鼀�矄�    ᨨ   ⼄盐 ᆠ泐ᨨ 㜠鼀犨矄 ᲼㝐� 졠 � 꾀�҈桌 㡰 和鼀 㜠҈�矄盐和鼀 㜠�矄 矄 㡰 和鼀 㜠҈�矄 矄和鼀 㜠�矄盐 ᆠ㡰 和鼀 㜠҈ �矄 盐 和鼀 㜠 �矄 盐 盐 和鼀  㜠 �矄 ᨨ   ᆠᨨᆠ   �ᨨ  ᨨ 矄鼀 㜠҈ 㡰 和鼀 㜠҈ �矄 盐 和鼀 㜠 �矄 盐  和鼀 㜠�矄 ᆠᨨᆠ  �ᨨ ᨨ 和鼀 㜠҈ ᔼ ᆠ�犨ᆠ 㡰㦨꾀矄� wᆠ�矄鼀�盐 鼀ᨨ 盐 泐 鼀ᨨ 盐ᨨ矄�� 鼀 㡰㦨꾀矄� w鼀   ⼄盐�ᨨ ᨨ 鼀ᨨ 盐 矄�� ᲼ᔴ鼀 㡰桌  �矄鼀ᨨ 盐�ᨨ �   矄ᆠ�泐 ᲼㝐� 졠 � 꾀�黨҈桌 㡰 Cm t㡰㦨A ҈졔矄� wmt㡰矄� wct  㡰 Cm t㡰㦨A ҈졔矄� wmt㡰矄� wmt ҈ ᆠ㡰 Cm t㡰㦨A ҈졔矄� wmt㡰矄� wct ҈ 㡰 Cm t㡰㦨A ҈졔矄� wct㡰矄� wmt 

Answer Key Topic-1 : Communication Systems ҈ ҈҈ ҈ ҈

㡰 ᆠ㡰 㡰 ᆠ㡰

 ҈  

㡰 㡰 ᆠ㡰 㡰

 ҈  

ᆠ㡰 㡰 㡰 ᆠ㡰

 㡰 ҈ ᆠ㡰  ᆠ㡰

� 㡰 ҈� ᆠ㡰 � 㡰

 㡰 ҈ 㡰  㡰

䰘 ᆠ㡰 ҈䰘 㡰 䰘 㡰

 ᆠ㡰 ҈ ᆠ㡰  㡰

黨 ᆠ㡰 ҈黨 ᆠ㡰 黨 㡰

҈ ᆠ㡰  㡰  㡰

WWW.JEEBOOKS.IN

WWW.JEEBOOKS.IN

EBD_8341 PS-2



Physics ᆠ㡰 쟼 �泐 E µ AaT b P c  �㡰 ᨨ E = kAaT b P c 犨  k �矄 �鼀 矄�ᨨ 矄矄 ᆠᨨ 矄    a, b   c     ᨨ  矄 �鼀 矄�ᨨ ᨨ 鼀ᨨ鼀 盐鼀 P = M ҈ L҈T -҈ �鼀 矄�ᨨ ᨨ A㦨L �鼀 矄�ᨨ ᨨ �鼀T㦨T ҈ 盐� � 矄盐� ⼄盐�ᨨ  �㡰犨�

᲼ 桌㦨᲼a桌᲼b桌 㝐  㦨 㝐҈ ᲼b桌 ҈

M ҈LT - = M c La + cT b - c

泐 ᆠᨨ鼀�矄ᨨ

c㦨҈ a 졔 c㦨 b  c㦨

҈

c㦨҈a㦨҈⏌b㦨҈

\  E = A҈⏌ T -҈ P҈

m m = = m c e e  m

䰘

㡰



mc  ®  㝐 꾀 맔  ҈ 㝐   꾀 �鼀 矄�ᨨ 矄 ᨨ  矄�矄 ᆠ  㡰 㦨�Ӹ

ÞY µ

 �㡰

Z

᲼ A T  桌 Q Q = =  W ᲼ MLT - 桌

 㦨 ᲼㝐 ҈ 꾀桌 F Z =B= IL  㦨 ᲼㝐 꾀҈桌

᲼QF㦨ILB桌

᲼ M -҈ L-T  A 桌

é e ù ê ú= ëê m  úû



Q F=

҈

é e =ê  m  e  êë m  e

ù ú 㦨e C᲼LT ҈桌맔᲼e 桌 0 0 úû é ù ҈ = Cú êQ m e êë úû

 pe  r 

᲼ AT 桌 ᲼ MLT - 桌 ´ ᲼ L 桌

= ᲼ A M -҈ L-T  桌

é e ù \ ê  ú = ᲼ LT -҈ 桌 ´ ᲼ A M -҈L-T  桌  = ᲼ M -҈L-T  A 桌 ëê m  úû b㡰 꾀矄 犨 ├ ᨨ犨

élù êë  úû = [ ]  [ ᆠ] = [ 꾀 ] é l ù é ù \ê ú= ê = é 꾀 ҈ ù ë ᆠ û ë 꾀 ûú ë û ҈҈

҈�

矄� � �㡰㡰

e 

q

Þ ᲼e  桌 =

\ V µ h I ҈G ҈C � ҈

æ -  ö ç ÷ ç a├ ÷ ø abè

҈䰘

é ù

\ ê a├ ú 㦨 㝐 

Þ

Þ᲼a桌 㦨 㝐҈ 

҈

  �矄    �泐  矄�泐 ᨨ  鼀� �ᆠ m

é B  ù 쟼 �泐 ᨨᆠ ´ �矄ᆠ鼀  = ê ú= �矄ᆠ鼀 㡰 ëê m ûú Vᨨlume é MLT  ù ҈  = ú = ML T  ê  êë L úû

b㡰  ├ � �矄盐 �ᨨ  � lp㦨҈҈黨맔҈� 鼀

lp =

úû

 = 㝐   [ a ]㝐 -

㡰 ⼄盐 �泐 � 





෌ ҈ �  = - \  µ   ᔴ�

Nᨨ 㡰 和ᨨ� � ᨨ � V 㡰 µ h x I y G Z C r  -҈ h 㦨 ᆠ├矄ᆠᨨ 矄  = éë ML T ùû I㦨ᆠ盐 㦨᲼A桌 G 㦨 ෌��ᨨ  ᆠᨨ 矄  㦨 ᲼M҈LT桌  c㦨矄 ᨨ �� 㦨᲼LT ҈桌 V 㦨 ᨨ �㦨 ᲼ML T A҈桌 \ ᲼ML T A ҈桌㦨᲼ML T ҈桌  ᲼A桌泐᲼M ҈LT桌 ᲼LT ҈桌r Mx  z錐L2x졔z졔r錐Tx2zr錐Ay ᔴᨨ鼀� � �鼀 矄�ᨨ  ᨨ 㝐 꾀犨� 泐㦨҈ 㦨 㦨҈㦨�

Þ

b㡰 ᨨᆠᨨ � ᆠ�ᨨ 犨  犨ᨨᨨ鼀矄 = 和� ᆠ ᨨ  �鼀矄 �鼀 矄�ᨨ 矄矄

êë

㡰 ᲼Ӹ桌㦨᲼桌᲼ 桌᲼꾀桌ᆠ ᲼㝐҈ 桌 㦨 ᲼ ҈桌 ᲼㝐 桌 ᲼ 桌ᆠ ᲼㝐҈ 桌 㦨 ᲼㝐졔졔ᆠ ᆠ桌 ᔴᨨ鼀� �ᨨ犨ᨨ  矄� ᨨ 矄�鼀�鼀矄犨� 㦨҈졔졔ᆠ㦨҈ᆠ㦨 矄ᨨ� �ᨨ⼄盐�ᨨ 矄犨� 㦨㦨҈ᆠ㦨 矄ᨨ᲼Ӹ桌㦨᲼ 꾀桌㦨᲼꾀 桌 b㡰 �鼀 矄�ᨨ  ᨨ  ᲼h桌㦨᲼ML T҈桌 ᲼ᔴ桌 㦨 ᲼LT ҈桌 ᲼G桌 㦨 ᲼M҈L T桌  ᆠ �鼀 矄�ᨨ  ᨨ é hC � ù é MLT -҈ ù × é L�T -� ù û ë û ê ú㦨 ë é M -҈LT - ù ê G ú ë û ë û 㦨 ᲼ML T桌 㦨  �泐 ᆠ㡰 µ෌  泐 ᔴ �鼀 矄�ᨨ 矄 ᨨ ෌ 㦨 ᲼㝐҈ 桌 㦨᲼㝐 ҈桌 ᔴ㦨᲼ ҈桌 ᲼ 桌㦨 ᲼㝐 ҈ 桌 ᲼㝐 ҈桌泐᲼ ҈桌 ᲼㝐 ҈桌 㦨 ᲼㝐  졔泐  졔泐졔   泐 桌 泐ᆠᨨ鼀� � ᨨ犨矄 ᨨ 㝐   ᨨ  矄� 矄  졔泐㦨Þ 㦨泐  졔泐졔 㦨Þ� 졔 㦨  �㡰  泐 㦨҈ Þ 졔 㦨҈  ��㡰 和ᨨ� �⼄ 矄 �㡰  ��㡰

= 泐=

- -҈ 

᲼ MT A 桌 Ӹ 㦨 ᲼㝐  꾀桌 黨

҈

X

X = ᔴᆠ� ᆠ 㦨

Y=

æ ҈ ö ç = c÷ ç m e ÷ è   ø

Þ ᲼b桌㦨㝐 

hG c

㡰 鼀矄矄  矄㝐 µ ᔴ泐 㝐҈  㦨 Ἐ㡰  ҈ ҈㡰泐 㝐҈ ҈㡰 㝐҈  㦨 㝐  泐 졔   졔  泐

WWW.JEEBOOKS.IN

PS-3

Physical World, Units and Measurements 㦨҈ 泐졔 㦨 泐㦨

҈黨

Q

泐 㦨 졔҈㦨 㦨҈





㝐 㦨 ᲼ ҈ ᔴ ҈桌 b㡰 ␔ ├ ᨨ犨   矄�矄��泐

㦨

꾀 

=

ᔼ  턼 㦨 ᔼ㡰 꾀



᲼桌᲼ᔼ桌 ␔ ␔ Q = = é ᲼㝐 ù ⼄ �   ê ú ´ ᲼ 桌 ᲼ᔼ桌᲼ 桌 ëê ûú

ᆠ㡰  Ҙ   犨�  e m c   h 矄 ᨨᨨ犨矄 m 㦨 keambcchd ᲼MLTA桌 㦨 ᲼AT桌a ᲼M桌b ᲼LT҈桌c ᲼MLT҈桌d 㦨 ᲼Mb 졔 d Lc 졔 d Ta  c  d Aa桌 졠  ᆠᨨ鼀� � ᨨ  矄� 矄 犨 � a 㦨    �㡰 b 졔 d 㦨 ҈  ��㡰 c 졔 2d 㦨 ҈  ���㡰 a  c  d 㦨   �㡰 泐 ⼄盐�ᨨ  �㡰 ��㡰 ���㡰  �㡰 犨 � a 㦨   b 㦨  c 㦨  ҈ d 㦨 ҈

é h ù ú ë ce  û



u 㦨

�



㦨

é 㝐  ҈꾀҈ ù ë û

�鼀 矄�ᨨ 泐 f E ¹ E  ᆠ�ᆠ � 㡰

�ᨨ鼀ᨨ鼀  p㦨ᆠ � q㡰맔 �矄 ᆠ d㡰 ᆠ㡰 ᨨ犨ᨨ   ᨨ  �矄 盐鼀ᨨᆠᨨ 矄 



az = ᲼ M ° L°T °桌 kq

kq z ᲼ MLT - q -҈ 桌᲼q桌 é = MLT - ù \ a㦨 ë û ᲼ L桌 ᨨ盐 = ᲼ MLT - q-҈ 桌  z㦨᲼L桌 꾀矄 k = ├�

a a Þ b㦨 꾀  �鼀 矄�ᨨ 泐P㦨 b P MLT - = ᲼ M  LT  桌 \ ᲼b桌㦨 ML-҈T - F é -҈ - ù êQ P = A = ᲼ ML T 桌ú ë û Dq e A = 㡰 ᔴᆠ� ᆠC = Dt L DV Dq㡰 L DV = L \ X = e  L Dt A DV 㡰 Dt \



 p é 㝐 -҈-  꾀  ù é 㝐 -҈ - ù é 㝐҈  ù ë ûë ûë û é  꾀  ù ë û 㦨 p é㝐 -҈-҈+  -+   -  꾀  ù ë û é  꾀  ù ҈ ë û 㦨 㦨    ù p é p 㝐  꾀 ë û

턼 㝐 - = 㦨  鼀 㝐 ᔴ � = 㝐 -҈-  꾀  ᔴᆠ� ᆠᔴ㦨   ur ur 㡰 쟼ᆠ�ᆠ 盐  f E = E  S

 ᨨ �鼀 矄�ᨨ 泐

e  a hc

pe  ෌鼀

⼄҈⼄

㦨᲼㝐҈ 꾀桌 㡰 꾀 �盐鼀ᨨ鼀 盐鼀㦨鼀맔맔㦨㝐 ҈

\ 䰘

 = é 㝐  ҈꾀҈ ù ë û ҈   e = é 㝐  꾀  ù ë û -҈  - ù é 鼀 = é 㝐҈  ù ෌= 㝐 

ë û    ë û  

҈ ⼄҈⼄   pe 

  㦨

b㡰  �鼀 矄�ᨨ  ᨨ鼀盐ᨨ

ᨨ犨

b㡰 꾀矄犨 ├ ᨨ犨 =

p  ᔴ ᲼꾀 桌  ᆠ e = = 鼀 ᲼㝐 - 桌᲼ 桌

㡰  盐 � �u   犨�  e a h   c 矄 ᨨᨨ犨矄 ᲼u桌 㦨 ᲼e桌a ᲼a桌b ᲼h桌c ᲼C桌d 矄� � �鼀 矄�ᨨ  鼀 ᨨ  ᲼M҈LT졔A졔桌 㦨 ᲼A҈T҈桌a᲼L桌b᲼ML2T҈桌c᲼LT҈桌d ᲼M҈LT졔A졔桌 㦨 ᲼Mc Lb졔c졔d Tacd Aa桌 a 㦨  b 㦨 ҈ c 㦨  ҈ d 㦨  ҈ \

᲼㝐 - 꾀 - 桌 �鼀 矄�ᨨ 矄 ᨨ m 㦨 �鼀 矄�ᨨ 矄 ᨨ Î ᲼㝐 -҈-  꾀  桌

Þ e =

 -

\ ᲼m  桌 = ê ҈



㦨 ᲼㝐 꾀 桌 㦨᲼ 桌

㦨 ᲼㝐㜠 ҈㜠   桌᲼ᔼ 桌 㦨 ᲼㝐㜠 ҈㜠  ᔼ 桌 

 矄鼀 盐�  �  矄泐矄鼀矄 ᨨ 盐 �矄 ᆠ㡰 �鼀 矄�ᨨ 矄 ᨨ  m 㦨 ᲼㝐 꾀桌 �鼀 矄�ᨨ 矄ᨨ  Î  㦨 ᲼㝐҈ 꾀桌 �鼀 矄�ᨨ 矄 ᨨ  㦨 ᲼㝐 꾀桌 \

 ҈ ᔴᨨ 盐ᆠ��泐㦨 矄�矄��泐 㦨 꾀



҈  �矄 �鼀 矄�ᨨ 矄矄 盐矄 ᆠᨨ鼀� �ᨨ  犨ᨨ盐 p  pe ෌鼀 



a㦨

Dq 㡰 L DV Dq = = I  ᆠ盐 㡰 DV L Dt Dt æ ҈ö  ç ÷ e  E   矄 矄  �泐  矄�泐 �  �泐 è ø

=

黨

ᆠ㡰

盐 �ᨨ盐鼀

 - é҈ ù [ 쟼 �泐] ML T \ ê e E  ú = = = ᲼ ML-҈T - 桌   ᨨ盐鼀 ] ë û [ L

WWW.JEEBOOKS.IN

EBD_8341 PS-4



Physics 㡰

 d µ r x S y f z = K r x S y f z  犨  ⧤ �矄 



bᆠ㡰꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  �鼀 矄�ᨨ 矄ᨨ  �盐鼀ᨨ鼀 盐鼀 ᲼mvr桌㦨M LT   ᨨ 鼀矄矄᲼m桌㦨M LT 

�鼀 矄�ᨨ 矄矄 ᆠᨨ 矄 

MLT ҈ 㦨MLT  ÞT㦨 L

M  L҈T  = M x L-x M yT - yT - z 쟼⼄盐� � �鼀 矄�ᨨ 矄ᨨ  矄� 矄

mvr M  LT  = = L-҈ r L ҈ ҈ mv 㡰 E = mv  = = L-   m E L- L- P= = =  = L-  t T L - E L F= = = L- x L

㝐ᨨ鼀 盐鼀

p㦨mv㦨

M  L҈T  = M x + y L-xT - y - z

\x졔y㦨x㦨҈

쟼 �泐

҈ ҈ \ x = -  y㦨  

ᨨ犨

\n㦨

҈

ᔴᨨ 盐ᆠ��泐 s =

J � /A � t = = E F/q FA

ᨨᆠ 䰘

= é M ҈LT  A ù ë û 

MLT é a ù = ᲼ P 桌 Þ ᲼a桌㦨᲼PV  桌㦨 ú L ëV û

 ê

s= 

é q ù   - ê ú = ᲼ Fr 桌 = ᲼U ´ r 桌 = ᲼ ML T 桌 e ëê ûú

L 㦨ML� T 

᲼kBT桌㦨᲼U桌 㦨 ᲼MLT 桌 �鼀 矄�ᨨ ᨨ l㦨᲼L桌

J � A � t = = = ᲼M -҈L-T  A 桌 E F q Fa

㡰

\

᲼Y桌㦨

᲼M -҈ L-T Q  桌 ᲼ MT -҈Q -҈ 桌

 = ᲼U ´ r 桌 ´

æ ö X �� ÷ çQ Y =  Z è ø

= ᲼ M - L-T  Q  桌 㡰

e k BT 㡰

和㦨

nq

矄� �E㦨hv Þ ᆠ├矄ᆠᨨ 矄 

b㡰෌�  ᨨ矄��ᨨ  㦨 ᲼a桌 和  ҈㦨᲼b桌 꾀ᆠᆠ�ᨨ  㦨᲼桌 � 鼀ᨨ鼀 盐鼀㝐 ҈㦨᲼⼄桌 ᨨᆠ 㝐  㦨 ᲼桌

ᆠ㡰



和 b = = 

�鼀 a-b

᲼  桌 =

�  鼀ᨨ鼀 盐鼀 �鼀

᲼⼄ 桌 ᲼

a-b



Þ 㦨⼄졔b - a Þ 㦨⼄졔b - b - 㡰 Þ 㦨⼄b +  Þ 졔⼄㦨b  ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ

k B T 㡰

=



n q e 㡰

҈ ҈ = = ᲼L桌 - ᲼n桌᲼r 桌 ᲼ L 桌᲼ L桌

和㦨

æ q ö ҈ ҈ ´ ç ÷ ç e ÷ k BT 㡰 n  è ø

和 =

҈ ᲼ L- 桌

҈

 = ᲼ L桌 ᆠ㡰 矄� � C =

᲼U 桌 ᲼n桌᲼U ´ r 桌

= ᲼ L  桌

æ q ö ҈ ҈ ´ ç ÷´ ç e ÷ k B T 㡰 n҈  è ø

 = ᲼U ´ r 桌 ´ ᲼U 桌 ´



=

 =

҈

a-b + 㦨b \ a 졔㦨2b  ᆠᨨ�ᨨ  㡰�矄ᆠᨨᆠ ᨨᆠ =



 = ᲼U ´ r 桌 ᲼U 桌

ᨨ矄��ᨨ

᲼ a 桌 = �鼀 = =  a-b 和 ᲼b 桌 꾀ᆠᆠ�ᨨ  =

҈ ´ n = ᲼n桌 ´ ᲼r 桌 ᲼U 桌

 = ᲼ L- 桌᲼ L桌 = ᲼ L-҈ 桌

é  - ù E PS ë ML T û é  -҈ ù = = ML T h㦨 = ë û ҈ v éT -҈ ù ë û T

�

æ q ö ҈ ´n ç ÷´ ç e ÷ k BT 㡰 è ø

和㦨

᲼X桌㦨᲼C桌㦨᲼M ҈ L T  Q桌 ᲼Z桌㦨᲼B桌㦨᲼MT ҈ Q ҈ 桌



-

b 㡰 �鼀 矄�ᨨ 矄ᨨ ᲼n桌㦨᲼L桌᲼q桌㦨᲼AT桌

҈ ᲼ L-҈ 桌 ҈

me 

҈ ҈

᲼n



= ᲼r 桌 ´

᲼n



= ᲼ L桌  R =

m V mI㦨eV Þ  =



m e

æm ö = R = ç  ÷  e I è e ø m I ҈ = =  QV㦨RI㡰 㡰 eI㦨mV Þ e V R 㡰

҈ ҈



WWW.JEEBOOKS.IN

PS-5

Physical World, Units and Measurements ᆠ㡰

�鼀 矄�ᨨ 泐� ᆠᨨᆠ I㦨eC V

\

҈ V = =R \ eC I

㡰 \

҈ e

㝐 - =  = 㝐-҈ -҈ p  ´  -҈ 쟼 㝐 - = 㝐- -҈  ᆠ├ᆠᨨ 矄 h㦨 = v

-҈ l

鼀 ᆠᨨ 盐ᆠ��泐 ⧤ᆠᨨ 盐ᆠ��泐 㦨 꾀D

㝐 - ´  =  㦨 㝐

⧤҈

´  ´ ⧤

ᔴᨨ �ᆠ�  ᨨ  �矄ᆠᨨ矄�泐᲼h桌㦨

҈ m e

=R

�鼀 矄�ᨨ 泐 ᆠᨨᆠ mC I㦨eV

m V m R = = = ´ e IC C e

҈ 㦨Ҙ ҈ m e 



�鼀 矄�ᨨ 泐� ᆠᨨᆠ 黨 ᆠ 㡰 꾀矄 ᆠ├矄ᆠᨨ 矄 h矄 ᨨ �� c ���ᨨ ᆠᨨ 矄  G盐矄 矄矄�ᆠ盐 �矄 ᨨ � L 㝐矄矄M矄ᨨ Lµhx cy Gz  �㡰  㝐µhp cq Gr  ��㡰 �鼀 矄�ᨨ 矄ᨨ ᲼h桌㦨᲼M L T҈桌᲼c桌㦨᲼L T҈桌 ᲼G桌㦨᲼M҈ L T桌 矄� � � ᆠ� ᨨ  ᨨ鼀ᨨ� �泐 ᨨ  �鼀 矄�ᨨ 矄 ᨨ⼄  �㡰

᲼ M  L T  桌 = ᲼ M x L x T  x 桌᲼ Ly T  y 桌᲼ M  z L z T  z 桌

M L T㦨M xz㡰L x졔y졔z㡰T x  y z㡰 졠  ᆠᨨ鼀� �ᨨ犨矄 ᨨ鼀 ᨨ  矄� 矄犨� xz㦨x졔y졔z㦨҈xyz㦨 졠 矄ᨨ� � 矄⼄ 矄犨�

҈  ҈ y㦨  z㦨    hG L = K  錐K�矄ᆠᨨ 矄  \ c

� 

ᔼ  矄鼀犨泐矄ᨨ� �⼄  ��㡰犨�

 bᆠ㡰矄� �F㦨



  C =

҈

m e  pe  㡰 r    ᲼Q 桌 I T =  ᆠ᲼e桌㦨 㦨M҈L T  I   ᲼ F 桌᲼ r 桌 MLT - L ҈ ҈ ᲼ LT - 桌 = ᲼Ҙ桌㦨 -҈ -    ᲼e 桌᲼C 桌 ᲼M L T I 桌  = ᲼ MLT - I - 桌

҈



bᆠ㡰 泐 ᨨ 矄 盐鼀 㦨ᔴᨨ �ᆠ�  ᨨ  �ᆠ�ᨨ  㦨᲼MLT桌 � �鼀 矄�ᨨ 矄矄 ᔴ盐��矄 盐 �ᨨ  �ᨨᆠ��泐 盐鼀ᨨ ᨨ鼀矄 ᆠ泐� � 矄ᆠᨨ 㡰  ⼄盐 ᆠ泐矄ᨨ 矄 盐 �矄ᆠᨨ �.e.᲼MLT҈桌





ᆠ㡰

ᨨ 鼀

 ᆠᨨ 矄  ᲼ K 桌 = u B

\᲼⧤桌 = 㝐 - ⧤ -҈

q

҈ m e

\ C =

҈ m e

\ m = e-҈L-T  ᲼QC㦨LT҈桌 F A 㦨 ᲼M҈LT҈Q҈桌 �㡰㝐� �ᆠ 盐  f = BA = qv F ��㡰 㝐ᨨ 盐盐矄 ᨨ  ��� �泐㦨  㦨 ᲼ML҈T桌 A

꾀矄⼄盐矄�ᨨ TµPadbEc ᨨ᲼T桌㦨᲼P桌a᲼d桌b᲼E桌c ᨨ ᲼MLT҈桌 㦨 ᲼ML ҈T桌a ᲼ML桌b ᲼MLT桌c ᨨ MLT҈㦨Ma 졔 b졔 c Lab 졔 c Ta  c \ a졔b졔c㦨  �㡰 ab졔c㦨  ��㡰 ac㦨҈  ���㡰 和ᨨ� �⼄ 矄 �㡰 ��㡰  ���㡰犨� a㦨�⏌b㦨҈⏌c㦨҈⏌

Topic-3 : Errors in Measurements & Experimental Physics ҈

b㡰 ෌� ᨨᨨ  ��矄�ᨨ ᨨ ᆠ�ᆠ盐矄ᆠᨨ 矄ᆠ犨�盐�㦨� �ᆠ 㦨�鼀鼀 矄ᆠᨨ盐 ᨨ 矄ᆠ犨�盐�

�ᆠ ᨨᨨ  ��矄�ᨨ ᨨ ᆠ�ᆠ盐矄ᆠ � = 鼀鼀 = ҈ ´ ҈� 鼀㦨҈m鼀 �

=

W Q    㦨   ෌��ᨨ ᨨ �㦨 m m

�鼀 矄�ᨨ 泐矄鼀 ᲼MLT桌  㡰 ᨨ⼄盐t㦨F맔r맔矄� q  犨ᨨ├ ᨨ W㦨F맔d맔ᆠᨨ矄q �鼀 矄�ᨨ 泐t㦨W㦨᲼MLT 桌 �鼀 矄�ᨨ 泐�� 泐㦨 犨 �  㦨᲼L桌

\쟼㦨ᔴ㦨 ҈ 㡰 ␔├ ᨨ犨  

C=

䰘

hc 錐K'�矄ᆠᨨ 矄  G Q҈Q

҈ q = 錐᲼C桌㦨᲼M҈LTQ桌  u u ᔼ 盐ᆠ ᆠL㦨  錐᲼ L桌 㦨᲼MLQ桌 � RA L  R =  \᲼r桌㦨᲼MLT҈Q桌 矄�矄��泐r㦨 l t E ᆠ㡰 矄� � C = 犨 ᔴ㦨矄 ᨨ ��  B

ᔴᆠ� ᆠC㦨

x㦨

M = KἘ

꾀 �盐㝐ᨨ鼀 盐鼀㦨mvr㦨 ᲼MLT҈桌   ᲼L桌㦨Q⏌m᲼L桌㦨᲼LT桌

ᨨ⼄盐t㦨F 맔r᲼t桌㦨᲼MLT桌



҈ æ ö çQ u = K BT ÷  è ø 

꾀  盐 ᨨ  ᨨ ᨨ �矄 ᨨ矄�� 㡰 꾀� �鼀d㦨��䰘�鼀鼀 ��ᨨ ᨨ  Dd㦨䰘黨�鼀鼀 꾀矄 鼀矄盐  盐ᨨ犨ᨨ ���矄  ᆠ�鼀  ᨨ  矄犨矄 ᨨ盐 � 犨ᨨ ���矄  ᆠ�鼀

\ d = �� ± 䰘㡰 鼀鼀 a b ⏌  㡰 ෌�  Z = cd 

WWW.JEEBOOKS.IN

EBD_8341 PS-6

Physics ᆠ �ᨨ� Z,

҈

DZ  Da  Db ҈ Dc Dd = + + + Z a  b  c d  ҈ =  ´  + ´ ҈� + ´  +  ´ � = ҈�奠  

҈҈

㦨



��矄�ᨨ

和ᨨᆠᨨᆠ鼀矄盐鼀 �矄鼀矄盐鼀 ᨨ � �鼀盐�ᨨ ᔴ ᆠ㡰 ᔴᨨ  �ᆠ�矄㦨҈㝐和҈和

 䰘  ��矄�ᨨ  ᨨ   � 矄ᆠ ᆠᨨ� ᆠ� 矄 犨�   ��矄�ᨨ  ᨨ 鼀� 矄ᆠ   ᨨᨨ  �矄ᆠ�矄泐� ��� 矄� ᨨ   ᨨᨨ 鼀� 矄ᆠ ᨨᨨ㦨䰘맔҈㦨䰘鼀鼀㦨䰘ᆠ鼀  � ᨨ  ᆠ泐� 㦨鼀矄盐 盐 ᨨᨨ 㦨 ҈졔맔҈㡰䰘㦨䰘ᆠ鼀 㡰 ␔   矄ᆠ犨 ᨨ   矄ᆠ犨㜠�盐� �矄 ��  矄�  ᨨ�ᨨ 矄 � 鼀ᨨ矄泐鼀鼀ᨨ  鼀� 矄ᆠ

=

҈

䰘

D҈㦨A҈졔B҈졔C҈㦨졔䰘졔�㦨

҈

҈ ҈�

D㦨A졔B졔C㦨�졔҈黨҈졔҈㦨䰘 ᨨ ᨨ  ᨨ�ᨨ  鼀ᆠ 矄 ᆠ㡰 ෌�  � ᨨ 矄�鼀 盐盐鼀l㦨�ᆠ鼀

�鼀ᨨ ᨨ矄ᆠ��ᨨ T㦨�s

�鼀 �ᨨ  ᨨ   盐盐鼀

l g

p l p l Þ g = g T Dg Dl DT = + Þ ᆠ�ᨨ ᨨ� �㦨 g l T Dg æ ҈ ö ҈ æ ö Þ =ç ÷ +  çè ÷ø =  g è � ø � Dg \ ᆠ � ᨨ � g = ´ ҈ = 奠 g M M ᨨ 盐矄㡰 d = =  = Ml - V l ҈ æ ҈ö Dd DM Dl  + ç = + = è ҈ ÷ø 㦨҈├�⏌鼀  ҈ d M l

㦨�맔҈㦨�맔҈鼀鼀 졔ᨨ㦨맔�맔҈ 鼀鼀 㦨҈�맔҈鼀鼀㦨҈�鼀鼀  � �㦨㝐和 졔ᔴ和  졔ᨨ㡰 㦨��鼀鼀졔 맔�맔҈㡰҈� 㦨��졔҈�㦨�䰘�鼀鼀 ᆠ㡰㝐 �鼀盐鼀ᨨ㦨҈�奠졔 ҈奠㡰㦨�奠 㡰 㝐 �鼀盐鼀ᆠ �ᨨ� 꾀

㦨҈�졔졔҈�졔҈�㦨�奠 ҈

Þ T =

黨

�ᆠ ᨨ ᨨ ��矄�ᨨ

=  奠 ᨨ � 㡰 +  奠 ᨨ � 턼㡰 ҈ + 奠 ᨨ � 㡰 + ҈ 奠 ᨨ � 和㡰  ҈ =  ´ � +  ´ ҈ + ´  + ҈ ´ ҈� 

D㦨A졔B졔C㦨�졔҈黨҈졔҈黨�㦨҈

T = p

҈- 

Þ㦨 ᆠ㡰 矄ᆠᨨ盐 ᨨ 矄ᆠ犨�盐� ᔴ㦨

D㦨A졔B졔C㦨졔҈졔㦨䰘



�ᆠ 盐鼀ᨨ  ��矄�ᨨ ᨨ ᆠ�ᆠ盐矄ᆠ

� ´ ҈ - =

 �ᆠ =

ᨨ 盐矄㡰

҈ æ ҈ö ´ ҈ +  ç ÷ ´ ҈ è  ø ��

㦨҈졔䰘㦨奠 b㡰 矄ᆠᨨ盐 ᨨ 鼀� 矄ᆠᨨ 矄ᆠ犨�盐�㦨҈鼀鼀 矄ᆠᨨ盐 ᨨ 矄ᆠ犨�盐�

=

 = � 鼀鼀  �ᆠ � 鼀鼀 = \ 矄 ᆠᨨ盐 ᔴ = � CSD ҈ 鼀鼀 = ҈ mm = ҈ᆠ鼀 = ҈ \

l  l ᨨ g = p g T

Dg DR DT ´ ҈ = ´ ҈ +  ´ ҈ g Q T

�ᆠ ҈ = =   ᆠ鼀  ᔴ�ᆠ盐矄ᆠ ��矄�ᨨ �

黨ö æ = ç҈ - ÷ ´ ҈ = ҈ 鼀鼀㦨҈ᆠ鼀 ҈ è ø



T = p

㡰 �ᆠ├ 矄矄㦨㝐和  � �졔ᔴ�ᆠ盐和ᆠ  � � ᔴ㡰  ᔴ =

�

㡰 A㦨䰘맔�黨㦨䰘ᆠ鼀

矄盐矄 ᨨ盐    矄�� � �ᆠ  ��盐矄 矄ᨨ A㦨䰘ᆠ鼀 㡰 ␔ 

㡰 矄ᆠᨨ盐 㦨

㦨

盐ᨨ ҈ᨨ 鼀� 矄ᆠ 盐鼀ᨨ 矄ᨨ  �矄ᆠ

� ᆠ鼀 㦨�맔҈ᆠ鼀 �맔҈

 � �㦨맔�ᆠ鼀졔맔�맔҈ᆠ鼀 㦨 졔҈�㡰ᆠ鼀㦨҈�ᆠ鼀 �ᆠ├ 矄矄ᨨ 犨�㡰 ҈䰘

㡰 和盐 ᆠ 矄�ᨨ  T =

rhg ´ ҈ 

�ᨨ� 矄盐 ᆠ 矄�ᨨ 

DT Dr Dh = + +   Q�҈ᆠᨨ 矄 㡰 T r h ᆠ �ᨨ

҈ ´

DT æ ҈  ´ ҈ ҈  ´ ҈ö =ç + ÷ ҈ T è ҈� ´ ҈  ҈� ´ ҈  ø

㦨 졔黨㡰 㦨 ҈黨㡰㦨҈黨奠@ ҈�奠

WWW.JEEBOOKS.IN

PS-7

Physical World, Units and Measurements ҈

D ҈ D D Dᆠ D = + + +     ᆠ ҈ = ´  +  ´ ҈ +  ´  +  ´ � 㦨奠  ҈黨

d 㦨 � 졔  맔 ҈ 졔  㦨 �黨 ᆠ鼀

ᆠ㡰 ෌� 㦨҈⏌ ᆠ  㝐 �鼀盐鼀�ᨨ

b㡰 \

 ᨨ  犨㦨L㦨鼀

�鼀├  泐矄ᨨ ᨨᆠ   ᨨᨨ鼀 ᨨ 犨

t҈㦨

҈ ö L æ  ç 盐矄� �L = gt ÷  è ø g

㝐  �鼀 㦨 �

쟼ᨨ㦨᠀҈ 泐 ᨨ  � 盐 ᆠ�ᨨ 㡰 㦨  mA㡰 ´ 

L v

ᨨ�鼀 ├  �   ᨨᆠ矄矄�矄 �� 泐

㦨҈졔 㦨 \

d 㦨

L L + g v

䰘

\



҈ dL 









 D ҈  +  D   +  D   +  D     +҈+  +  = = ҈� 

ᆠ㡰

D =

꾀矄 矄ᨨ盐�ᨨ ᨨ 鼀矄盐� �ᆠᨨᆠ├�矄҈�  ᨨ 鼀

�鼀矄 ᨨ盐 黨᠀҈� b㡰 ᨨ ᔴ҈  � ᆠ� ᔴ㦨҈㝐和҈和㦨҈鼀鼀黨鼀鼀㦨҈鼀鼀㦨҈ᆠ鼀 ᲼Q҈和㦨黨㝐和㦨黨鼀鼀桌  � �㦨㝐和 졔ᔴ맔和 㦨졔 ҈㡰맔䰘㦨䰘ᆠ鼀 ᨨ ᔴ  � ᆠ� ᔴ㦨҈鼀鼀҈҈鼀鼀 ᲼Q҈和҈҈㝐和㦨҈҈鼀鼀桌 ᔴ㦨҈鼀鼀㦨҈ᆠ鼀  � �㦨졔 ҈䰘㡰맔҈㦨ᆠ鼀 㡰 꾀矄�㦨 p

L

T Dg DL DT 和ᨨ ´҈ = ´҈ +  ´҈ g L T ҈ ҈ ´҈ +  ´ ´҈ 㦨䰘 ; 奠 㦨  黨 ҈  㦨 ҈ ᆠ鼀 b㡰 矄 ᆠᨨ盐  㦨 ҈ d҈ 㦨 � 졔  맔 ҈ 졔  㦨 ҈ ᆠ鼀 d 㦨 � 졔  맔 ҈ 졔  㦨 �䰘 ᆠ鼀

Þ

҈҈ � - D =  

\

D = -� ᨨ

b㡰 꾀ᆠᆠᨨ � � ᨨ   ⼄盐矄�ᨨ 

Dt ҈ = t 黨 Dl ҈ l㦨 ᠀҈㡰ᨨ = l  Dg 奠=䁸 g

t 㦨 黨᠀҈㡰ᨨ

� 㡰 ᔴ = 㦨҈鼀鼀 � ᨨᨨ㦨�맔҈㦨�鼀鼀 ��㡰  � �㦨 �졔�맔҈㡰졔�㦨鼀鼀

҈

b㡰 㝐矄盐  � ᨨ ᨨ 㦨�ᆠ鼀 ᨨ �和ᆠ犨� ҈㝐� 和ᆠ��矄�ᨨ 㦨҈鼀鼀 黨㝐� 和ᆠ��矄�ᨨ 㦨҈ �和ᆠ��矄�ᨨ  矄ᆠᨨ盐 㦨҈㝐和҈和㦨҈鼀鼀 㡰 ᔼ  ᨨ鼀

 µl

 ҈ dL dL + g  L v

 dT dL ´ ҈ = ´ ҈ ᆠ�ᨨ ᨨ L ҈ L  ҈ = ´ ´ ҈ ; ҈奠 ҈ 

҈ ´ ҈㡰 㦨鼀꾀 

㦨├l ᨨ犨��矄�� 쟼㦨҈҈ᨨ ᨨl҈㦨ᆠ鼀  㦨�ᨨ ᨨl㦨ᆠ鼀  ᨨ�  � �ᨨ ᨨ鼀D   ҈҈㦨⧤  �D㡰㦨⧤

졠 矄盐矄�盐� � �� 盐矄犨� d 㦨

ᆠ盐 ᨨ��ᨨ ᨨ  �ᨨ �矄

I = e҈ V ⏌T - ҈㡰 鼀꾀 �� 㡰 ␔   I = �mA e҈ V ⏌T = mA ҈ 꾀矄ᨨ dI = e҈ V ⏌ T 㡰 ´ T

�鼀├  泐�鼀ᆠ矄ᨨ盐 ᨨᆠ   矄ᨨ 

t =

㡰

҈ + �䰘 + �黨 㦨 �黨 ᆠ鼀 

꾀矄 犨 ├ ᨨ犨

l p 2l Þ g =  g t Dg D l D t æ ö æ ҈ +  ´ ҈ ö ᨨ = ± ç +  ÷ 㦨 ç ÷ 㦨䰘 黨 ø è l g t ø è  t = p

\ 黨

Dg 奠 = 䰘奠 g

b㡰 ᔼ  鼀矄盐鼀   �鼀ᨨ ᆠ泐�  㦨㝐和 졔 和 㡰맔 ᔴ㡰ᔴ㦨 ҈㝐和҈和㡰

æ � ö ÷ = ҈ ᆠ鼀 è � ø

㦨 �҈� - �҈㡰 - ç 

\ 㡰

㦨�҈졔맔҈㦨�҈ᆠ鼀

鼀 �鼀盐鼀ᨨ矄矄�ᨨ� Y 盐ᨨl d

DY Dl  Dd = + Y l d

矄ᆠᨨ盐 㦨



�ᆠ ᨨ ᨨ ��矄�ᨨ ᨨ ᆠ�ᆠ盐 矄ᆠ

� 鼀鼀 㦨 � 鼀鼀 ҈

Dd㦨Dl㦨�鼀鼀 쟼ᨨᆠᨨ �盐�ᨨ ᨨ l 㦨

Dl � 鼀鼀 ҈ 㦨 㦨 � 鼀鼀 � l

WWW.JEEBOOKS.IN

EBD_8341 PS-8

Physics 쟼ᨨᆠᨨ �盐�ᨨ ᨨ d㦨

҈

ᆠ㡰

҈  Dd  맔 � 鼀鼀 㦨 㦨 � 鼀鼀 � d

�



ᆠ㡰

�ᆠ

ᨨᨨ  ��矄�ᨨ 矄ᨨ ᆠ�ᆠ盐矄ᆠ � = ҈鼀鼀 㦨 �

矄ᆠᨨ盐  =

�鼀r㦨㝐和 졔 ᔴ和 㡰맔 ᔴ㡰

ᨨᨨ㦨�맔LC.㦨�맔҈鼀鼀㦨�鼀鼀 �鼀ᨨ 㦨᲼  � �ᨨ 鼀� 矄ᆠ桌졔᲼  � �ᨨ ᆠ�ᆠ盐 矄ᆠ맔LC桌ᨨᨨ 㦨�맔졔�맔҈�㦨҈鼀鼀

� 㦨䰘鼀鼀 � ҈ Dr ҈ Dr = ᨨ ´ ҈ = 䰘 䰘 r r m m ᨨ犨  矄�泐 d = = V  æ r ö pç ÷  èø Dd ´ ҈ ᆠ �ᨨ�   矄�泐 d ì Dm æ Dr ö ü + ç 㦨 í ÷ ý ´ ҈ è r øþ î m Dm æ Dr ö ´ ҈ +  ´ ç 㦨 ÷ ´ ҈ m è r ø ҈ = ҈҈奠 㦨奠졔맔 䰘

�鼀r㦨�鼀鼀졔맔

\





䰘

\

㡰

黨

㡰

ᨨ盐鼀ᨨ ᆠ盐 V㦨 l 㦨 ҈맔҈ 鼀㡰 㦨҈䰘맔҈鼀 ÞV㦨҈䰘맔҈鼀 꾀矄  �  矄 犨ᨨ矄�� � �ᆠ  ��盐矄矄ᨨ ᨨ盐鼀 矄 矄ᨨ 犨ᨨ 矄�� � �ᆠ  ��盐矄 E t㡰㦨Aeµt㦨Aet

\

ᨨ�E㦨ᨨ�At

졠  �  �� �犨�

dE dA dt =   ´ t E A t 꾀矄 ᨨ矄 犨泐矄  盐

 =  ´ ҈

) (

⏌鼀

)

㦨�졔�㦨҈҈�



 꾀 ᆠᆠ盐泐├ ᨨ犨  \ᆠ �ᨨ� Ӹᨨ盐 �矄鼀ᨨ 盐盐矄



DY DD Dl ᨨ犨 = + l Y D ᲼Q  盐ᨨ mg L ᆠ桌 ҈ � + 㦨  ´ 㦨맔�졔�   Þ DY㦨Y맔҈҈�㦨맔҈҈҈맔҈҈�㦨�맔҈҈҈ =  ´ ҈҈҈ ⏌鼀   � �ᨨ Ӹᨨ盐 �矄鼀ᨨ 盐盐矄㦨 Y졔DY㡰 \ = (  ±  ) ´ ҈҈҈ ⏌鼀 

dE æ dA ö æ dt ö ´ ҈ =  ç ´ ҈ ÷ + t ç ´ ҈ ÷ E A t è ø è ø dE Þ 맔҈㦨맔҈�奠졔맔�맔҈�奠㦨奠 E FL 㡰 Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 Y = A´l \

㦨҈鼀鼀鼀鼀㦨鼀鼀

(





盐� � 盐矄ᨨ Dl฀lDT T犨�쟼҈㦨҈�奠 矄鼀ᨨ �쟼҈쟼 쟼

҈҈

ᆠ �ᨨ�   矄�泐

Dr  ´ ҈ = ´҈ = 奠 r ҈

l l  l Þ T  = p  Þ g = p g g T Dg ´ ҈ ᆠ �ᨨ� g㦨 g Dl DT ´ ҈ +  ´҈  = l T

F A mgL  ´҈ ´ 黨 ´  = =  l L pD  l p  ´ ҈- ´  ´҈-

 �㡰

 Dr = r ҈

҈ ҈ ´ ҈鼀鼀 㦨鼀鼀  ��矄�ᨨ 矄ᨨ 鼀� 矄ᆠ㦨  

Y=

m m m 㦨 = l p r v Al

ᨨ鼀 ⼄盐矄�ᨨ 盐� �  盐矄ᨨ Dl 㦨ᆠ鼀 l =  ᆠ鼀錐 Dr㦨�ᆠ鼀錐r㦨�ᆠ鼀 m㦨�錐Dm㦨�� ⼄  �㡰犨�

␔├ ᨨ犨 矄ᆠᨨ盐 ᔴ㦨҈㝐和҈和 b㡰 �鼀�ᨨ ᨨ 矄�鼀 盐盐鼀�矄��  泐

b㡰

 矄�泐 r =

Dr Dm Dr Dl = + + l r m r

T = p



㡰

├� �ᨨ�  �  � ᨨᨨ矄

㡰  ��矄�ᨨ 矄ᨨ   �矄ᆠ 㦨҈ ��矄�ᨨ 矄ᨨ 鼀� 矄ᆠ \҈ ��矄�ᨨ ᨨ   �矄ᆠ 㦨

Dg Dl DT = + g T l

Dl  DT矄  盐鼀ᨨ  � �矄├ 鼀 �鼀盐鼀 � ᨨ�ᨨ  㡰  ᨨ 鼀矄盐鼀 ᨨ g�矄鼀ᨨ矄ᆠᆠ盐

 ᆠᆠᨨ �盐�ᨨ ᨨ 鼀 �鼀盐鼀ᨨ矄矄�ᨨ�   鼀矄盐鼀 ᨨ y 盐ᨨl d�矄 矄鼀 矄ᆠᨨ盐 ᨨ 矄ᆠ犨�盐�

�ᆠ � = = = ҈鼀鼀 㦨 Dr ��矄�ᨨ 矄ᨨ ᆠ�ᆠ盐矄ᆠ �

㡰 �ᨨ� g

 ҈

҈ ´ ҈ -� DY DL ´ ҈ 㦨奠 ´ ҈ = ´ ҈ 㦨 Y l � ´ ҈ -�

҈�㡰  矄�泐 r =

 M M Þ r = MD - =  p V  æ Dö pç ÷  è ø

æ Dr ö Dm æ DD ö \奠ç ÷ = + ç =  +  ´ ҈� = ҈�奠 è D ÷ø è rø m

WWW.JEEBOOKS.IN

PS-9

Physical World, Units and Measurements ᔴᨨ  �ᆠ�㦨҈㝐和҈和

æ Dr ö ҈� æ x ö 奠ç ÷ = 奠=ç 奠 è ҈ ÷ø è r ø ҈

æ è

㦨 ç ҈ -

\ x = ҈� 

꾀矄黨㝐和㦨҈和

҈㡰

犨ᨨᆠᆠ�ᨨ矄ᔴ҈ ᔴ ᆠᨨ

ᆠ � 矄�矄

\

ᔴᔴ ҈ ҈ ҈ = + Þ ᔴ⼄ = ҈  ᔴ ⼄ ᔴ҈ ᔴ  ᔴ҈ + ᔴ 

ᔴ ⼄ =

�

㦨 ҈MSD -

Dᔴ Dᔴ Dᔴ ҈ ҈ ҈ = + Þ -  = - ҈ -  ᔴ⼄ ᔴ҈ ᔴ ᔴ⼄ ᔴ҈ ᔴ

Q҈㝐和㦨҈鼀鼀㡰  � �ᨨ 矄� l㦨㝐和 졔和  ᔴ㡰㦨҈鼀鼀졔҈맔҈鼀鼀 㦨҈҈鼀鼀㦨҈҈ᆠ鼀

é ù  Dᔴ҈ Dᔴ Þ Dᔴ = ᔴ⼄ ê  +  ú ᔴ úû êë ᔴ҈   é ҈ ҈� ù Þ Dᔴ = ´ + ê � � ë  ´   ´  úû

ᨨ犨  矄�泐㦨

黨  + ҈� ´ =  � � 쟼 �泐矄ᨨ �  ᆠᆠ�ᨨ = ҈ ´

҈ ᔴ  Þ  D Þ ´ ҈ = 





和� ᆠ

\ Y㦨

␔├ ᨨ犨  

 �㡰 䰘

=

D

D 䰘䰘 ´ ҈ = ´҈ = ҈奠 = ҈黨奠 

㦨

҈ ´ ҈ ´ ҈ æ � ´ ҈  pç ç  è



҈ � ´ ҈- 㡰 ´ ҈� ´ ҈- 㡰

Fl AY

ö ҈҈ ÷÷ ´  ´ ҈ ø

; 鼀鼀

㦨맔҈҈҈⏌

鼀 \㝐 �鼀盐鼀ᨨ矄矄�ᨨ�  鼀矄盐鼀 ᨨ Y DY㦨 黨㡰Y 㦨黨맔맔҈҈҈ 㦨҈黨맔҈҈⏌鼀  ᆠ鼀 㡰

҈鼀鼀 = ҈鼀鼀 ҈

ᔴ盐 矄盐 ᆠ㦨 prl = p

\D 㦨䰘䰘  ᆠᆠ �ᨨ�  鼀矄盐鼀 ᨨ  ᨨᆠ �

㡰␔├ ᨨ犨 Dl㦨

� ´  ´ ҈҈ ´ ҈-

�鼀㦨MSR졔CSR맔 ᔴ㡰 㦨҈鼀鼀졔䰘맔 ҈㡰鼀鼀㦨҈䰘鼀鼀

(  ) (  ) (  )



X F L ´ 㦨  L X pD 

W㦨�錐D㦨�ᆠ鼀㦨�맔҈鼀錐 X㦨҈�ᆠ鼀㦨҈�맔҈鼀錐 L㦨҈҈ᆠ鼀㦨҈҈맔҈鼀

矄ᆠᨨ盐 ᔴ㦨

和盐矄�盐� � 盐矄� ⼄  �㡰

�

F A

æ DY ö æ DD ö DX DL = ç + + çè ÷ è D ÷ø X Y ø 鼀 L æ ҈ö æ ҈ö æ ҈ ö 㦨  ç + + = 黨 è � ÷ø çè ҈� ÷ø çè ҈҈ ÷ø

æ҈ ҈ö 盐±D盐㦨 䰘��㡰± ç + ÷ 㦨 ±�㡰ᆠ鼀 è ø æ҈ ҈ö ±D㦨 ҈�䰘�㡰± ç + ÷ 㦨 ±�㡰ᆠ鼀 è ø

+

ᨨ盐 � �ᨨ ᨨ矄�� � �ᆠ  ��盐矄㡰 ҈黨×҈҈N⏌鼀㡰

㝐 �鼀盐鼀ᨨ� Y

㦨�졔㦨҈奠

盐矄 ᆠ �ᨨ�  ᆠᆠ盐�ᨨ ᨨ   �泐矄ᨨ �矄҈奠 ҈黨㡰

�

m 䰘 g 鼀矄矄 = = = �⏌ᆠ鼀 ᨨ盐鼀 l  ҈҈㡰

Ӹᨨ盐 �矄鼀ᨨ 盐盐矄Y =

D Dᔴ D ´ ҈ = ´ ҈ +  ´ ҈  ᔴ⼄  ´�  ´҈ +  ´ ´҈  �

 ҈ ҈ - =  盐 D D盐 D \+ +  =   盐 ҈ ҈ ҈ ҈ ҈ ҈ = ᨨ犨  - = Þ  盐  - ҈ ҈ Þ = \ = ᆠ鼀 

  �  鼀├� � ᨨ  � 矄ᆠ 犨�ᆠᨨ� ᆠ�  犨�    鼀�

矄ᆠᆠ盐矄矄ᆠᨨ盐 �矄҈鼀鼀 �ᆠ鼀㡰 ᔴ㦨҈MSD ҈VSD

黨 MSD  Q黨MSD 㦨҈VSD㡰 ҈ 黨ö æ æ ҈ ö ҈ MSD 㦨 ç ´ ҈÷ 鼀鼀 㦨҈鼀鼀 㦨 ç҈ - ÷ MSD 㦨 è ҈ ø è ҈ ø ҈

 ´    = � �

=

黨 ö ÷ = ҈ 鼀鼀 ҈ ø

㦨 

D l 㦨pDl 

 맔҈䰘맔�鼀鼀㦨�䰘ᆠ鼀 䰘

㦨ᆠ鼀 ᨨ盐 � �ᨨ ᨨ犨ᨨ矄�� � �ᆠ  ��盐矄㡰 b 㡰

鼀 =

� + � + �䰘 + � + �黨 = �� » � 和 

쟼ᨨ�  � � 鼀  ҈錐 鼀  錐 鼀  錐 鼀  錐

鼀   �

㝐 ᨨ =

 +  + ҈ +  +  = ҈ » 和 

WWW.JEEBOOKS.IN

EBD_8341 PS-10

Physics

\

奠ᨨ�  鼀矄盐鼀 ᨨ � 

ᨨ�鼀  㦨 矄ᆠᨨ 矄 =

ᨨᨨ ᨨ矄ᆠ��ᨨ 矄  DT DT ҈ ҈ \ = Þ = Þ DT = �矄ᆠ T   

�鼀�ᨨ  T =

 D

´ ҈ = ´ ҈ = �䰘奠 

� 奠ᨨ�  鼀矄盐鼀 ᨨ �

D� D

æ D + D ö ´҈ =  ´҈ + ç ÷ ´҈ �

è - ø æ ҈ +҈ ö 㦨  ( �䰘 ) + ç ÷ ´҈  » ҈҈奠 è  - ҈ ø

黨

ᨨ犨 ᨨ鼀矄盐� �ᨨ� �g

\ � =  p

D ҈ ´ ҈ = ´ ҈ = ҈奠  ҈

\ᆠ �ᨨ� �g

bᆠ㡰  �ᆠ�矄

҈ᆠ鼀 㦨҈�ᆠ鼀 

�和㦨㝐和 \҈和 =

�

 ´ ҈� 㦨҈ᆠ鼀 �

ᔴ㦨҈㝐和҈和 㦨҈�ᆠ鼀҈ᆠ鼀㦨�ᆠ鼀 和ᆠ犨�盐� ᔼ  �ᆠ  ᨨ  矄ᆠ犨�盐��矄犨�ᆠ ᔴ ᨨ  �ᆠ�矄   �ᆠ 㦨맔ᔴᨨ  �ᆠ�㦨맔�㦨�ᆠ鼀 ᔴᨨ 矄ᆠ犨�盐�

�ᆠ

ᨨ ᨨ ᨨ ��矄�ᨨ 矄 ᨨ ᆠ�ᆠ盐 矄ᆠ � ᆠ鼀 㦨�ᆠ鼀㦨�鼀鼀 㦨 ҈

�

ᨨ犨�   矄ᆠᨨ盐 ᨨ   � 矄ᆠᨨ   矄ᆠ犨�盐��矄 犨�ᆠ  矄ᆠᨨ盐 ᨨ  �ᆠ�矄 

ᔴᨨ � 矄ᆠᨨ 矄ᆠ犨�盐�㦨맔�㦨�ᆠ鼀

 �ᆠ 㦨맔�㦨҈ᆠ鼀

҈ \ᔴᨨ 矄ᆠ犨�盐�㦨 ᆠ鼀㦨҈ᆠ鼀㦨҈鼀鼀 ҈ l 㡰 Q 矄� q㦨 l \ 㦨 ᆠᨨ矄ᆠ q  �㡰  㡰 l = [ - ᆠᨨ矄ᆠ q ᆠᨨ q] \ q  l \ 㡰㦨 ᆠᨨ矄ᆠqᆠᨨq q  ��㡰 

Dg Dl DT ´ ҈ = ´ ҈ +  ´ ҈ g l T Dg æ ҈ ö \ ´҈ =  +  ç ÷ ´҈ 㦨�奠 g è  ø Dr D ҈ - a㡰 D ҈ + a㡰 æ ҈- a ö = + b㡰 r = ç ÷ Þ r ҈ - a㡰 ҈ + a㡰 è ҈+ a ø Dr Da Da Da ҈ + a + ҈ - a 㡰 = + = Þ r ҈- a ҈+ a ҈ - a 㡰 ҈ + a 㡰  Da ҈ - a 㡰 D a \ Dr = = ҈ - a 㡰 ҈ + a 㡰 ҈ + a 㡰 ҈ + a 㡰 ᆠ㡰 矄� � N = N  e -lt Þ  N =  N  - l t

҈ dN = -t N dl DN  Dl = = =  Nt  ´ ҈

Þ

�

n졔҈㡰和㦨n㝐和 \

҈和㦨

n ö æ = ç҈ è n + ҈÷ø 㝐和 ҈ a 㦨 㝐和㦨 盐 �矄᲼Q ҈㝐和㦨盐 �矄桌 n +҈ n +҈

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈

ᆠ㡰

҈ 㦨᲼ ҈桌

ᨨᨨ ᆠᨨ 矄盐 �ᨨ盐鼀㦨᲼桌鼀���泐ᨨ  

꾀矄 q � ᆠ矄矄 ᨨ鼀   ᨨ 黨  ᆠᨨ q ᆠ矄矄    ᨨ

꾀 桌 矄ᆠ Îᨨ  㦨 ᲼㝐҈ 꾀

㡰  ᆠ矄矄

Dt DT ҈ = = t T 

ᔴ � e㦨ᔼ㦨᲼꾀 桌 �盐 ⼄盐 ᆠ泐 w㦨

㡰 㦨ᆠᨨq q

\

n 㝐和 n +҈

矄ᆠᨨ盐  ᔴ㡰㦨҈㝐和҈和

�� � � ��㡰泐 �㡰犨�

�.e.  ᆠ�ᨨ ᨨ� d ᆠ矄矄 ᆠ㡰   � ᨨ  矄� �ᨨ 矄�鼀 盐盐鼀�矄 ᆠ泐鼀 �� 㡰  ᨨ ᨨ�  � Dl㦨 盐  ᨨ矄矄���泐ᨨ ᨨ� 鼀矄盐� ��鼀�矄҈矄� 矄矄   矄 ᆠᨨ盐  ᨨ 矄ᨨ 犨ᆠ �矄 ҈矄



�  ��ᨨ  犨�  矄ᆠ ᨨ l

㦨

�҈

l

奠ᨨ�  鼀矄盐鼀 ᨨ r

҈㝐和㦨

�

 Þ T  = p  l  g g

盐矄� � T = p

ᨨ犨矄盐矄�盐� �  �鼀 矄�ᨨ 矄ᨨ ᨨ⼄盐 ��矄犨�

Ne  㦨 m Îᨨ 

L- AT  M M -҈ L- AT 

= T - = T -҈ 㦨w



Ne  c m Îᨨ = pn = p Þ l = pc l m Îᨨ Ne 

b㡰

wp =

㦨  ´

 ҈ - ´҈-҈҈ ´  ´ ҈ 㦨 鼀 䰘  ´ ҈䰘 ´ ҈ ´ ҈ -҈黨 㡰 

WWW.JEEBOOKS.IN

PS-11

Motion in a Straight Line

Motion in a Straight Line

2



Topic-1 : Distance, Displacement & Uniform Motion ҈

b㡰 ෌� v㦨 b x ᨨ

dx = b x҈⏌ dt

ᨨ

x

t





-҈⏌ ò x dx = ò bdt

ᨨ꾀 �� � 矄  ᨨ �鼀   ᨨ 泐 �矄  犨ᨨ �   ᨨ矄��ᨨ 矄 A  B �    ��  ᨨ矄��ᨨ

�鼀 �  犨 �ᆠ  �矄 ᨨ ᨨ矄矄�

Topic-2 : Non-uniform Motion

x҈⏌ bt  㦨t ᨨ x㦨 ҈⏌   �  �� �犨�鼀犨�

҈

㡰

ᨨ 



dx b ´ t =  dt





�

�鼀



vu㦨aS 盐 a =

�矄 ᆠ

 ®

C

Þv㦨 ҈ 

R O �矄ᆠ鼀 

B







æFö \ v = u  -  ç ÷ S èmø

҈ ҈ 鼀⏌矄 = 䰘鼀⏌矄 Þ v =  

b㡰 x㦨at졔btct

dx d = at + bt  + ct  㡰 dt dt 㦨a졔btct

ᨨᆠ�泐 v =

꾀ᆠᆠ�ᨨ 

® vf

Dv ␔

F m

é � ´ ҈- ù  Þ v  = ҈㡰 - 㡰 ê ú - ëê  ´҈ ûú ҈

 p 㡰 �矄ᆠ鼀  㦨 矄 ᨨ矄 �矄 ᆠ

 pr 㦨 pR A  b㡰 꾀� ᆠᆠ�ᨨ

uur ur uur ur r r v f - v� v f + -v� 㡰 D v a= = = t t t

҈ æ ҈ ö ҈ �  � 䰘 鼀 + = çè + ҈÷ø ´  + ´ ´   =        b㡰 ᨨ鼀   �  ⼄盐�ᨨ  ᨨ 鼀ᨨ�ᨨ

=

r ҈ =  ´ =  鼀⏌矄  Q r㦨҈鼀錐t㦨҈矄㡰 t ҈

㦨 ACB =

� 矄㡰

҈ ҈ =   ҈ � SD =  - =   �矄 ᆠ ᆠᨨ  泐   ᨨ 泐㦨  ᨨ v㜠t � 㦨 OABS㡰졔 SCD㡰

 �矄ᆠ鼀   b㡰 꾀�ᨨᆠ�泐㦨 �鼀

㦨AB㦨AOB㦨 R �矄 ᆠ 㦨    �

t

OS =  +

b t ᨨ v㦨  b㡰 ෌ 矄� ᨨ�ᨨ  ᆠ㡰ᨨ矄��ᨨ 㜠 �矄 ᆠ �鼀   ᨨ�ᨨ  㡰 ᨨᆠ�泐㜠 ᨨ矄��ᨨ   ᆠᨨ矄ᨨ � � ᨨ ᨨᆠ�泐㜠�鼀� ᨨ�ᨨ  㡰 �矄 �矄 ᆠ㜠�鼀� �矄 矄 ��

ᨨ犨 ᆠ �矄 ᆠ㜠�鼀� ᨨ�ᨨ  㡰 �矄 � ᆠᨨᆠ

㦨 

t㦨t㡰

 A B v 鼀⏌矄㡰  S D O  ҈�  C

æb ö ÷ è c ø

ᨨ㦨bc맔t \ t = ç

vf㦨졔�鼀⏌矄

ö  æ æb ö æ b ö = a+b  c ç ÷ ÷ ç ÷ c ø è è c ø è c ø

 v㦨 a + b ç

㜠v� 㦨졔�鼀⏌矄

r  Dv = v f + v� = � + � = �  鼀⏌矄 r r  Dv  �  ҈ = = a =  鼀⏌矄 �  ᨨ 㜠犨矄 �ᆠ�ᨨ  Dt ҈ 

dv d a 졔 bt 㜠 ct  㡰 㦨 dt dt



㡰 ᨨ ᆠᨨ 矄  ᆠᆠ�ᨨ    �矄 矄��  �  ®  ᨨ㜠 �矄ᨨ  a - t ® ® ᔼ ᆠ�  矄�� � ᨨ  v - t  ᨨᨨ  x - t 

WWW.JEEBOOKS.IN

EBD_8341 PS-12

�

Physics

ᆠ㡰 �鼀├ 泐꾀ᨨᆠ  � �矄 � �ᨨ� �矄 \ �鼀├ 泐ᨨᆠ  � �矄 � �ᨨ� 㦨졔

ᨨἘtἘᨨ鼀� �鼀盐鼀

x

盐㦨

҈é ҈ x ê- + v êë  d  + x

꾀 㦨҈

҈ ҈  = 꾀 = ҈   =     + 㡰    Þ ҈   =   (   +  ) Þ Þᨨ㦨

(

)

҈    

(

҈ +  

҈   

)

  

       㦨 ҈   +       

ᨨ  = ҈   

ᆠ㡰 矄� �⼄盐�ᨨ a㦨

v u ҈   S㦨ut졔 at t 

�矄 ᆠ 泐ᆠ� ҈�矄ᆠ㦨

҈ �㡰  ҈�㡰  ҈�

䰘� 鼀  �矄 ᆠ 泐矄ᆠᨨᨨ� ҈�矄ᆠᨨ 矄㦨맔҈�㦨� Q �矄 ᆠ㦨矄 맔�鼀㡰 �  ᆠ 犨  �矄 ᆠ   泐ᆠ   矄ᆠᨨᨨ � ҈�矄ᆠ�䰘�㦨҈҈�鼀  ᆠᆠᆠ 矄 矄ᆠᨨᨨ �  �鼀錐

䰘

QM - x t҈ =  �㡰 v

�鼀├ ᨨ  �矄 ᆠἘRP Ἐ�   �

t =

d  + x v

 ��㡰

ᨨ�鼀矄 ᨨ鼀ᨨ ᆠ ᨨ鼀QᨨP

t = t҈ + t =

QM - x d  + x + v v







d = ᨨ x =   - ҈ ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  ᨨᆠ �矄 鼀ᨨ� � 犨� ᆠᨨ 矄  �� ᆠᆠ�ᨨ  �  㦨  ᆠᨨ 矄  ᔴ㡰

黨

 ├  = - ᔴ + ├  = +  ᔴ ᔴ  ᆠ �  㡰 矄 矄 ᆠᨨᆠ泐 b㡰 �矄 ᆠ ᨨ �  �  � �矄ᆠ鼀  s㡰 㦨t Q s µ t  �� 㡰 泐 ᨨ盐 �  ��ᨨ  ᨨ  �矄ᆠ鼀  犨 � ᆠᆠ�ᨨ 

ds dt  dv d t  = = t = = t    a = dt dt dt dt a㦨tᨨ a µ t  ᆠ �  㡰 �矄 ᆠᨨᆠ ҈ 㡰  ⼄盐�ᨨ  ᨨ   ��  v㜠x �  �矄 v v㦨  x + v  �㡰 x

V=

v dv =-  dx x

㦨

䰘� + � t  ҈�㡰 = t  䰘�졔�䰘�㦨 Þ ҈�㦨䰘� Þ 㦨�矄ᆠ 㡰  ᆠ盐 ᨨ   �� 犨泐 �矄 ᆠἘxἘ ᨨ鼀  ᨨ� 㝐和ᨨ 㝐㦨x 꾀 � 矄 ᨨ ᆠ�  � �矄v  �鼀├ 泐 ᆠ ᨨᆠᨨ   �矄 ᆠ QR㦨 QM x ᨨ    �� 犨泐



  = -ᔴ  㦨ᔴ

 

 = (    ) =



҈      =   

盐� � �矄盐ᨨ � ⼄盐�ᨨ  �㡰

ù ú= úû



d

 㦨 졔㡰 꾀㦨 Þ 㦨҈ 졔㡰㦨 ҈㡰 �㡰

dt = dx

\a㦨 v Þ

ù v é v dv v =  ´ v =   ê   x + v ú  ᨨ鼀 �㡰 dx x x ë x û 







v v a㦨  x x x

 ��㡰

졠  ᆠᨨ鼀� �  ⼄盐�ᨨ  ��㡰 犨�  ⼄盐�ᨨ  ᨨ  矄��  �  y㦨mx졔c

v

 犨�m㦨  = +  x 

�  q 㦨졔� q �矄ᆠ盐 

v 꾀矄ᨨc㦨 -  

x �   y㜠� ᆠ �矄 ��  ᆠ�  㡰ᆠᨨᆠ泐 �ᆠ矄 ᆠᨨ矄ᨨ � �a㜠x �  ҈҈ b㡰 ᔴ  � �  ᨨᆠ�泐㦨  盐    ᆠᆠ�ᨨ 㜠�鼀 � ҈ 㦨 ´ ҈ ´ ҈҈ = �� 鼀 ⏌ 矄  和� ᆠ � �� ᨨᆠ�泐�矄 ᨨ �  ᨨᆠ�泐� 鼀 �鼀盐鼀 ᨨᆠ�泐�矄��鼀⏌矄

WWW.JEEBOOKS.IN

PS-13

Motion in a Straight Line ҈ 㡰 A



鼀矄 ҈ a㦨鼀矄  x B

鼀矄 ҈



鼀





鼀

ᨨA

u҈ =  鼀矄 -҈  a҈ = -鼀矄 - s҈㦨xt҈㦨t ҈  a҈t҈  x㦨t t

s҈ = u҈t҈ +

\

 �㡰

ᨨB u㦨鼀矄҈a㦨鼀矄s㦨xt㦨t

҈  s㦨ut졔      x㦨t 졔t 꾀 � �⼄ �㡰  ��㡰

҈

t㦨

 ��㡰

 㦨矄 �

u

㡰

A



B t � �矄 ᆠ   㦨꾀 ᨨ 矄 㜠�鼀 � O

҈ ´ � ´  =  鼀  ҈ 㡰 �矄 ᆠ�矄犨� �鼀矄x㦨at졔bt졔c  =

Þ x

和 ҈



ᆠ  �� ᨨᆠ�泐  = = 鼀⏌矄 �鼀 ҈ ᨨ QS�矄 �ᨨ 㦨鼀⏌矄 ᨨ OPa ᆠᆠ�ᨨ 㡰>鼀⏌矄 ᨨ PS ᆠᆠ�ᨨ 㡰鼀⏌矄 ᨨ ORᆠᆠ�ᨨ a 鼀⏌矄 ᨨ RS �ᨨ a >鼀⏌矄  ᆠa³矄ᨨ鼀ᨨ� ᨨᨨ� 矄� �矄  ҈ �㡰t҈ �鼀├ 泐 ᆠᨨ�  鼀 �鼀盐鼀 ᨨᆠ�泐vm 犨 � � �矄 ᆠᆠ�ᨨ  矄� �㦨u졔at v vm = + at҈ ᨨt҈ = m  �㡰 a 和� ᆠ   ᨨ �鼀 矄  �矄 t   ᆠ ᆠᨨ矄 ᨨ �鼀t㦨 tt҈㡰ᨨᆠᨨ鼀泐矄a㦨b v㦨 矄� v㦨u졔at v  = vm - b t - t҈ 㡰ᨨt҈ = t + m  ��㡰 b 矄� � �㡰�  ��㡰犨� =

\

㦨� \

졠 ᨨ OQᆠᆠ�ᨨ  a㡰

vm v æ ҈ ҈ö = t - m ᨨt = vm ç + ÷ a b èa bø t ab ᨨ vm = a + b㡰

dx dx at + b㡰 dx = at + b Þ x = at + b Þ = dt dt x dt

 ���㡰



Þx

d  x æ dx ö +ç ÷ =a dt  è dt ø 

æ dx ö æ at + b ö a -ç ÷ a -ç ÷  d x è dt ø = è x ø Þ = x x dt 

=

ax  - ( at + b ) 

2

=



ac - b 

x x  Þ µ  ᆠ 㦨 ҈� ᆠ 㡰 꾀t㦨 t㦨҈ᨨ 泐�矄矄 ᔼ ��泐 a �矄 ᨨ矄�� 矄ᨨ     ᨨ 泐 ᆠ⼄盐�矄 矄ᨨ鼀 ᨨᆠ�泐   a 矄 ᨨ盐   �� 矄ᨨ     ᨨ 泐 ᆠᨨ鼀矄ᨨ矄 ᆠa ᆠ

ᨨ鼀� ᨨ矄�� ᨨ�鼀 �  �   £ t £ ҈

 ᨨ盐 泐�矄 �ᆠ  �    ᨨᨨ犨� � v㜠t � 

ᨨ�鼀ᨨ ᨨ盐 泐㦨҈矄ᆠ

ᨨ �矄ᆠ鼀 㦨҈鼀㦨꾀盐  v㜠t㡰� v鼀 =

��㡰 ᨨ �矄 ᆠ 㦨 ᨨ DABC ҈ ҈ 㦨 ´ 矄 ´ �盐  㦨 ´ t ´ v鼀  



s  ´҈ = =  鼀⏌矄 t ҈

҈ æ ab ö  ab ҈  t 㦨 ç ´t ´  è a + bø÷ a+b  Topic-3 : Relative Velocity in One Dimension 㦨

҈

㡰 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  �  A   B  盐

� � ᨨ

 ᆠ├矄 �    ᨨᨨ矄� �ᆠ�ᨨ 

҈├鼀⏌

├鼀⏌ A

WWW.JEEBOOKS.IN

EBD_8341 PS-14

Physics 꾀矄   ᨨᆠ�泐ᆠᨨ鼀ᨨ   ᨨ A  Bᨨ � 矄鼀�  OA

VA =  ├鼀⏌ 㦨҈鼀⏌矄

䰘├鼀⏌

VB = -䰘 ├鼀⏌ 㦨鼀⏌矄



VMA㦨҈├鼀⏌ 㦨�鼀⏌矄 V鼀 B㦨V鼀 A졔VA, B 㦨V鼀 A졔VA  VB㦨�졔҈ 㡰 㦨�졔㦨黨�鼀⏌矄 㡰  턼  �矄 ᆠ턼㦨맔 ᨨ  �矄 ᆠ㦨矄 맔 �鼀㡰 �矄 ᆠ턼 㦨 

ᆠᨨ矄 ° =

\

t0 =

vA ҈  = = 鼀矄-҈ ᆠᨨ矄°  

�矄ᆠ鼀  � � = = = �矄 ᨨᆠ�泐 vB 矄� °  ´ ҈ 

æ ö ç  ÷ 쟼ᆠ 矄ᨨ KLMN鼀ᨨ矄犨� 盐 � ᨨ鼀矄 è ø v矄盐ᆠ  K犨泐矄 鼀ᨨ �ᆠ泐ᨨ犨 矄LL �ᆠ泐 ᨨ犨 矄 M M �ᆠ泐ᨨ犨 矄 N   N �ᆠ泐ᨨ犨 矄 K ᨨ  矄�矄ᨨ 矄泐鼀鼀泐犨ᆠ 矄泐 KLM N犨�鼀 ᆠ ᨨ  矄⼄盐ἘOἘ 꾀  泐� 矄  ᨨᆠ�泐ᆠᨨ鼀ᨨ  ᨨ � KO 㦨 v ᆠᨨ矄 �

\





҈ ³矄ᆠᨨ³  矄ᆠᨨ 和 � �   矄ᆠᨨ 犨� ᨨ盐 犨├� �   矄  �矄 矄ᨨ 矄 矄  犨├� � ᨨ 泐�矄

和ᨨ  矄ᨨ 矄 矄 �矄

҈ ҈ ҈� ³矄ᆠᨨ³ + =    ҈ 矄ᆠᨨ

和ᨨ �鼀ᨨ�ᨨ盐 矄ᆠᨨ  = �㡰

҈ 㦨 矄ᆠᨨ  �

꾀㦨҈



º 

 矄�

 

�

  º º

ᆠ鼀





 ᆠᨨ矄



�ᨨᆠ�泐ᨨ B犨� 矄ᆠᨨA�矄 �ᆠ盐 ᨨ � ᨨ 鼀ᨨ�ᨨ ᨨ A�OA

黨



O



d 

 ⧤



� 



�矄 ᆠ

�鼀├ ᨨ鼀ἘOἘ = ᨨᆠ�泐

ᨨ t = 䰘



v

�矄 ᆠKO㦨dᆠᨨ矄� 㦨

҈ ³矄ᆠᨨ³  矄ᆠᨨ ␔├� � 犨�    矄ᆠᨨ �ᨨ� �   矄   

�

vB =

盐矄

 = ҈  矄ᆠᨨ ᆠ㡰

Þ

㦨

鼀⏌矄ᆠ

鼀 ෌� 盐ᔴ㦨盐㦨ᔴ㦨鼀⏌矄㦨鼀⏌矄  ᆠ�ᆠᆠ�ᨨ  ᔴ 㦨  鼀⏌矄ᆠ ҈ ᨨ犨犨├ ᨨ犨 矄 = 盐 +    ҈  = ´   Q 盐 =    ᆠ ᆠ犨�ᆠᆠ 盐犨�  盐矄 �鼀



vBᆠᨨ矄 㦨vA㦨 ҈ 



 졠矄㡰

鼀⏌矄ᆠ ᔴ

ᆠ㡰



턼 턼

҈  ´   = Þ  =    

\

B

d



v



=

d v

矄㡰꾀矄 ᨨ  �  �矄 鼀ᨨ� � �    �ᆠ�ᨨ  ᨨ  矄 ᨨ�ᨨ    ᨨ   �    ᨨᨨ矄� �ᆠ�ᨨ  和ᨨ 矄矄盐   犨� �   b㡰 ᨨ鼀ᨨ� �ᨨ矄  ҈

 泐ᨨᆠ矄  ᨨ鼀ᨨ �    ᨨᨨ矄� �ᆠ�ᨨ    �矄  �矄 �矄 ᆠ盐矄   �盐 矄  ᨨ     泐 ᨨᆠ犨ᨨ矄�矄�꾀矄    ᨨᆠ 鼀ᨨ矄 犨泐    �盐 ᨨᆠ�泐 ᆠ矄矄    ᨨ �矄 矄  矄鼀矄 ᨨ  q 矄矄  �矄  ᨨᆠ 鼀ᨨ矄 q҈ 鼀� 矄 矄�ᨨ 泐

Q q > q҈ \w > w҈ ᨨ鼀   ᆠᨨ ᆠ ᨨ  � ᨨᆠ�泐 r r r  ҈ 㦨   ෌  ҈෌ 犨 ෌�矄 ᨨᨨ泐 鼀 㡰 㡰 ᨨ Bᨨ � ᨨ泐㜠A�ᨨᆠ�泐 ᨨ 犨AvBA 矄 ᨨ盐 ᨨ �OA和ᨨvBA 犨�鼀├

 �� 犨� 졔 㡰X㜠 �矄 B v BG 㡰 q㦨� vTG q  ´ � = = ° � \ f㦨 ҈�   犨� 졔X㜠 �矄 � A ҈� ᔼ DOMA f q 㦨�  q 㦨�  Þ ÐOAM㦨�  O

M

WWW.JEEBOOKS.IN

PS-15

Motion in a Straight Line \ ÐOAB㦨҈� 꾀矄ᨨÐBOA㦨 � 㦨҈� 矄� �矄� 犨� DOBA

ᨨ

�

vT 矄� ҈�°  - ҈㡰 ´ 䰘҈ = ;  鼀⏌矄 矄� ҈�° �  ᆠ矄 ᨨ 犨�ᨨ盐 vB㦨鼀⏌矄

ᨨ犨v㦨u졔at Þ



҈ s = ut + at  

Þ -h =

 gh t -

҈  ҈ gt Þ gt  -  gh t - h =   

 gh ±  gh +  ´ ᨨ t =



g ´h 

ædö 

䰘

矄� � S = ut +

꾀矄⼄盐�ᨨ �矄⼄盐 �ᆠ矄ᨨv㜠h� 犨�ᨨ v

Þ 㦨 t h=d

 

d ҈

ᔼ ��泐ᨨᆠ�泐 �矄 ᨨ犨 犨 矄 㡰        ᆠᨨ�矄�ᨨ �矄矄�矄 �ᆠ�ᨨ 犨� 矄矄鼀� �盐 � ᨨᆠ�泐 �矄 盐犨 矄 졔㡰 ᨨ �鼀t㦨ᆠᨨ矄ᨨ 矄ᨨ ᨨ� ᨨ  � 犨 h㦨d  �鼀ᆠᨨ�矄�ᨨ ├矄ᆠ 㡰 ᨨ  ᨨ 泐  ᨨ犨  �ᆠ泐 盐犨 矄 ᆠᆠ�ᨨ

鼀� 矄 ᆠᨨ 矄   a 㦨  g㡰   ᨨᆠ�泐   泐�鼀 t �矄 �� 泐V㦨 u gt 盐� � �矄 ᨨᆠ�泐 ᆠ矄矄 � 泐   盐� �  ᨨᆠ�泐 � ᆠ矄矄 � 泐   �ᆠ�ᨨ  �矄 ᨨᨨ矄� ᨨ ᆠ  ᨨ   ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄 ᨨᆠ�泐 矄盐矄 �鼀 b㡰 泐҈㦨҈�錐泐㦨� ᨨ 泐҈㦨鼀㦨矄 \ 泐泐҈㦨 ᨨ矄

㦨gt

Þt=

҈ ®   V� ᆠ矄矄 ᨨ犨 犨 矄 h  ® ᨨᆠ�泐ᆠ  �矄�矄 �ᆠ�ᨨ

 ®   V ᆠ矄矄盐犨 矄

҈  ҈ gt Þ S =  ´ t + gt    ᲼Q S = ҈m桌

 g

… �㡰

æ ҈ö ҈ sᨨ 泐矄 �矄 ᆠᨨ ҈黨m矄ᨨ�  ç t  ÷  è ø �矄 ᆠ   㦨 ҈

ᔼ 矄

ᆠᨨ�矄�ᨨ  ├矄  ᆠ



v æ vö çè ÷ø =  ᨨv㦨 v Ἐ   Þ v Ἐ =  vἘ 꾀矄   �ᆠ�ᨨ  �矄 矄    矄  �矄 ᆠ矄  矄ᨨ �  㡰 ᆠᨨᆠ泐 �ᆠ矄  矄 ᆠᨨ ��ᨨ 矄 㡰  ├矄 �鼀ᨨᆠ  �ᨨ盐 \

ᨨ t =

v  = u  ±  gh

nu =  ᨨ鼀⼄盐矄�ᨨ 㡰 g g Þ gH㦨n n㡰u 㡰 ᨨ 盐 � ᨨ鼀泐 ᆠᆠ  ᨨ ᆠ�ᨨ  鼀ᨨ�ᨨ

v  = u  ±  gh  ⼄盐�ᨨ  �矄 ⼄盐 �ᆠ  ᆠ v  h � 犨�   ᨨ ᔼ �� ᨨᆠ�泐 ᨨ犨 犨 矄 矄ᨨ ��   ᆠᨨ�矄�ᨨ  � 矄矄 �矄 �ᆠ�ᨨ  犨�  矄鼀 盐  ᆠ ᨨᆠ�泐 �矄 盐犨 矄 盐  v Ἐ =  g ´ ç ÷ = gd 錐 è ø

g 

h  gh h ҈ + 㡰 Þ t = ҈ + 㡰 ᨨ t =  g g g ᆠ㡰 ᨨ 盐 � ᨨ鼀泐ᆠᆠ ⏌ ᆠᆠ  鼀ᨨ�ᨨ  

u  g

u + u  +  gH

Þt =

 gh

ᨨ犨ᆠ├犨�矄鼀ᨨ� �盐 ��泐  ἘtἘ    �鼀 ├  泐   ᨨᨨ  ᆠ├ ᨨ ᆠ    �ᨨ盐 

u  +  gh = -u + gt

�鼀├ ᨨᆠ  �� 矄 ᨨ� �矄 t =

ᆠ㡰 ᨨ 盐犨  鼀ᨨ�ᨨ  ᨨ  �ᆠᨨ

v  = u  +  gh Þ v  =  +  gh Þ v =

盐 

Topic-4 : Motion Under Gravity



ᆠ㡰

v㦨 u  +  gh

vB =



҈  �  和  ᨨ  ᆠ � � �ᨨ盐

泐泐҈㦨

vB vT = 矄� ҈�° 矄� ҈�°

҈

>矄



ᨨ犨



҈ æ ҈ö æ ҈ö g ç t  ÷ = ҈ \ g ç t  ÷ = ҈´   è ø è ø

҈´  æ ҈ö Þ çt  ÷ = g è ø \

҈ ҈ =   ҈ ´ 㡰  g

Þ

g =  ҈   黨 㡰

Þ

ᨨ鼀⼄ �㡰

g = 

\�㦨m⏌s 

T盐㡰꾀矄  矄ᆠ├ᨨᨨ� ᨨ ᨨᆠ�ᨨ 矄ᨨs㦨 \ vu㦨맔g맔s 㦨 \ v㦨u

WWW.JEEBOOKS.IN

EBD_8341 PS-16

Physics

Motion in a Plane

3



Topic-1 : Vectors ҈

㡰 矄� � R㦨A҈졔A졔A҈Aᆠᨨ矄q �㦨졔�졔맔맔�ᆠᨨ矄q ᨨ ᆠᨨ矄q㦨 ®ö æ ® çè  A҈ +  A ÷ø

�ˆ

®ö æ ®  ç  A҈ -  A ÷ 㦨A 맔A ҈ ҈ è ø

҈ 

㦨A҈졔黨A҈Aᆠᨨ矄qA҈Aᆠᨨ矄q A 㦨A҈A졔�A㜠҈Aᆠᨨ矄q 㦨맔맔�졔�맔맔� 㡰㦨҈҈�



ᆠ㡰 ᨨ鼀 ��盐  r ˆ  ˆ r  ෌ = � + ├ Þ  = ˆ + ├ˆ    

䰘

( )

 ö  r r æ  ö æ \   ෌ = ç ˆ + ├ˆ ÷  ç ˆ� + ├ˆ ÷ = ˆ  ˆ� è  ø è  ø  r r 㡰 鼀� �盐  ᨨ 犨ᨨᆠᨨ矄 꾀    㦨  r r  꾀 +   =   +   +   ᆠᨨ矄 q  r r  꾀    =   +      éëᆠᨨ矄 (҈°  q ) ùû



ᨨ

Þ

r r

 꾀





(҈+ ҈  ᆠᨨ矄 q)

 Þ

(҈+ ᆠᨨ矄 q ) =  (҈ ᆠᨨ矄 q)

\

r \ 㝐� �盐  ᨨ  ᆠᨨ  ᆠᨨ ᔴ =

�

 + ᆠᨨ矄 wt =   - ᆠᨨ矄 wt ҈ + ᆠᨨ矄 wt =  ҈ - ᆠᨨ矄 wt 㡰 p ҈ \ ᆠᨨ矄 wt =  ᆠᨨ矄 wt =  ᨨ wt =   p p ´t= \ t = 矄ᆠᨨ 矄  

Topic-2 : Motion in a Plane with Constant Acceleration

盐矄� � ᆠᨨ鼀ᨨ  ᨨ   ��  ᨨ  ᨨ鼀 犨 �



r

r r r r r P 졔 Q R = P Þ P+Q = P P P졔Q졔PQᆠᨨ矄q㦨P Þ Q졔Pᆠᨨ矄q 㦨 q a Q Q Þ ᆠᨨ矄 q =   �㡰 P  P 矄� q  a = = ¥ Q   ᆠᨨ矄 q + Q = 㡰 Q +  P ᆠᨨ矄 q Þ a㦨黨 r r r r 㡰 ෌�  A + B =  A - B

Þ

æ  ҈ ö q = ᆠᨨ矄 ҈ ç  ÷ r r r r r è +҈ ø 㡰 ᔼ  ᔴ = �ˆ + ˆ    꾀ᔴ = 꾀 졔㦨҈  �㡰 rr r r ᔴ = 꾀 㦨҈  ��㡰 和ᨨ� �⼄盐�ᨨ  �㡰  ��㡰犨� ҈  = =  



㝐� �盐  ᨨ  ᨨ⼄盐  t  = ҈黨� 黨㡰෌� 

\

  +   +   ᆠᨨ矄 q =    +      ᆠᨨ矄 q

  (҈+ ҈ + ᆠᨨ矄 q)



\ a �ˆ + a ᆠᨨ矄 wt �ˆ + a 矄� wt ˆ =  a �ˆ - a ᆠᨨ矄 wt �ˆ - a 矄� wt ˆ Þ ҈ + ᆠᨨ矄 wt 㡰�ˆ + 矄� w t ˆ =  ҈ - ᆠᨨ矄 w t 㡰�ˆ - 矄� w t ˆ

   㦨   +      ᆠᨨ矄 q   ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ 

r r  꾀 +  =

ˆ

t =  ҈ - = 䰘�ˆ - ҈҈ ˆ + �kˆ

졔 A㡰 A҈㡰ᆠᨨ矄q A҈㡰 A㡰ᆠᨨ矄qA맔A



҈黨�㡰 r ෌�  F = �ˆ +  ˆ + kˆ㡰  r 꾀  r = ᲼ �ˆ +  ˆ - kˆ㡰 - �ˆ +  ˆ + kˆ㡰桌 = �ˆ + ˆ - kˆ r r

ᨨ⼄盐 t = r ´ F = �ˆ + ˆ - kˆ㡰 ´ �ˆ +  ˆ + kˆ㡰

҈

㡰 ᨨ鼀 ��盐⏌ ��ᨨ ᨨ鼀泐 h҈ h =  �° \ h҈ = d d  h҈ h҈ + h 꾀  =  ° d +  d A

�

d

Þ h҈ + h 㡰 ´  = d

҈  + = 黨 黨

r r r S-P r r r 㡰  P + bR = S Þ R = b r r r 꾀矄ᨨ R = Q - P r r r r r r S-P r r = Q - P Þ  S - P = bQ - bP \  b r r r \ S = bQ + ҈ - b㡰 P

Þ h҈ + h 㡰 =

� 黨 

d 

Þ d + h =

\ h = d r 㡰 ෌�  u = � ˆ 鼀⏌矄 r 꾀ᆠᆠ�ᨨ  a = ҈�ˆ +  ˆ   � ᆠᨨᨨ �  y㡰� �鼀t ҈ S x = ux t + ax t  

 B d C

d 

᲼Q ux = 桌

WWW.JEEBOOKS.IN

PS-17

Motion in a Plane

Þ  =  +





�

҈ ´ ҈ ´ t  Þ t =  矄 

҈ S y = u y ´ t + ay t   ҈ y = � ´  + ´  ´  = ҈ 鼀  ҈  ᆠ㡰 矄� � S = ut + at  ҈ y = u y t + a y t  ᨨ � y 꾀 �矄㡰  ҈ ҈ Þ  =  ´ t + 㡰t  Þ ´  ´ t  =  Þt㦨s   ҈ S x = u xt + a xt  꾀ᨨ �x 꾀 �矄㡰  ҈ Þ x =  ´  + ´  ´   =   㡰 ෌�  ᨨ矄��ᨨ  ᆠᨨ r r = ᆠᨨ矄 wt�ˆ + 矄� wt ˆ r r dr = w  矄� wt�ˆ + ᆠᨨ矄 wt ˆ 㡰 ᨨᆠ�泐 v = dt 꾀ᆠᆠ�ᨨ  r r dv a= = - w  ᆠᨨ矄 wt�ˆ + 矄� wt ˆ 㡰 dt r r  a = -w  r r \ a �矄 �ᨨ rr r r r r 꾀矄ᨨ v  r =  \v ^ r

盐矄  �ᆠ�矄  ᨨ鼀� � 盐 � ᨨ鼀 ᆠ�ᆠ盐 鼀ᨨ�ᨨ  ® 㡰 r = ҈�t �ˆ +  - t  㡰 ˆ ®

v =

®

d r = t�ˆ - tˆ dt

®

®

꾀ᆠᆠ�ᨨ  a = d v = �ˆ -  ˆ

dt





䰘



\ a =  +  = � 鼀⏌矄  r r ҈r b㡰 꾀矄 和 = 盐 +    r ˆ + ҈ �ˆ+  ˆ㡰 和 = ��ˆ + 㡰 = ҈�ˆ + ˆ + �ˆ+  ˆ  r r  - � = ҈�ˆ + ҈ˆ r r r ᲼矄 矄 = ᆠ  � � ᨨ矄��ᨨ =  - � 桌 r  = �ˆ + ˆ r   =   ᆠ㡰 ᨨ鼀 ��  ⼄盐�ᨨ  r  = ⧤ 泐�ˆ + ˆ

(

)

泐 = ├泐  = ├  



泐  = = 泐 Þ 泐 泐㦨 ᨨ犨 泐  ᔼ �� � ᨨ  矄�  泐㦨 졔ᆠ �㡰 ᨨ��ᆠ�A XA㦨t졔t졔҈ r VA =   t 㡰�ˆ r aA = �ˆ

ᨨ�ᆠ�B YB㦨�t

r VB = t  ˆ r aB = -tˆ

꾀t㦨҈矄ᆠ

r r VA =   t 㡰�ˆ = �ˆ  vB =  ˆ r r r \ V B ⏌ A =  v A + vB = �ˆ   ˆ \和 ᨨ B犨A v =  + 

=  + �䰘 = �

黨

\ v㦨� 鼀⏌矄㡰 bᆠ 㡰꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ ⼄盐�ᨨ

泐=

 

泐=

꾀㦨

=  泐 =  ü ý ��

盐 =҈ þ



㦨

 

 㦨҈鼀⏌矄

泐=  泐 ҈ = ×  = Þ 泐㦨      ᨨ犨 �  ᆠ�犨�鼀

 泐  

泐 =

=

 æ ö +ç ÷   è  ø



×  +  

 泐 =  +  㡰ᔼ  㦨҈ �ᆠ�矄ᨨ���  㦨泐㦨㡰 泐㦨  泐㦨҈㦨҈鼀⏌矄 㡰  㦨 泐㦨 졔  Þ泐㦨  ᔼ  㦨 㦨ᆠᨨ 矄 㦨҈ Þ泐㦨ᔼ㦨҈ ᆠ㡰 꾀㦨 㦨泐㦨  矄 㦨҈錐泐㦨 Þ 㦨҈ 㡰  㦨�鼀�矄 㦨҈矄 泐㦨 졔   Þ泐㦨  Þ泐㦨  ᔼ  㦨Þ 㦨ᆠᨨ 矄 � ��泐  㦨҈㡰Þ泐㦨҈㦨҈ 꾀㦨҈矄ᆠ 泐㦨졔泐맔㦨҈맔҈㦨҈ 泐  q = =  q® �犨�   �矄㡰  \  q =

泐

҈ = = ҈ Þ q = �°  ҈

WWW.JEEBOOKS.IN

EBD_8341 PS-18

҈

Physics x㦨aᆠᨨ矄 Þ ᆠᨨ矄 㡰㦨

bᆠ㡰

x a

y b 和⼄盐� �  � �⼄  �㡰  ��㡰犨� y㦨b矄�  Þ 矄�  㡰㦨

x

+

 �㡰

R 㦨vxT =

 ��㡰

y

=҈ a  b  ᆠ   ᨨ    �ᆠ �矄 �矄 ᨨ鼀   ��  ⼄盐�ᨨ 矄 犨ᆠ  � 

Þ R = 

u h ´ g 

 u  g

ᆠ㡰 ෌� y㦨x黨x 졠 ᆠᨨ鼀� �犨� 

y = x  q -

gx 

u  ᆠᨨ矄 q



␔   q㦨ᨨᆠᨨ矄q㦨

҈



d x dx  = v x = - ap 矄� pt 錐   = ax = - ap ᆠᨨ矄 pt dt dt dy = v y 㦨 ᆠᨨ矄 pt dt 

dy dt



= a y = -bp  矄� pt 

꾀�鼀t㦨

p p ᨨpt㦨  

p =  㡰 졠 泐  vx   ay    ᨨ 犨 ᆠ  矄泐   ᨨᆠ�泐 �矄 ᨨ �

�� x㜠 �矄   ᆠᆠ�ᨨ  ᨨ � �� y㜠 �矄 p  ᨨᆠ�泐 ᆠᆠ�ᨨ ᨨ  �ᆠ  ᆠt㦨 p  ᨨ鼀 ᨨᆠ  ᨨ  꾀t㦨 tᨨ矄��ᨨ ᨨ  �ᆠ r r t 㡰 = x�$ + y $  = a ᆠᨨ矄 pt $� + b 矄� pt ˆ a x    v y  ᆠᨨ鼀 ᨨ ᆠ盐矄 ᆠᨨ矄



=黨 = 黨 ᨨ  u ҈ ⏌ �㡰  u ᆠᨨ矄  q \ u㦨�⏌鼀⏌矄 㡰 R犨�矄鼀 ᨨq 黨 q.

�鼀ᨨ  �� 矄 u 矄� q t҈㦨  g u 矄� 黨° - q㡰 u ᆠᨨ矄 q = t㦨 g g 

 æ u  矄� q ö  R æ u 矄� q ö æ u ᆠᨨ矄 q ö ÷= ᨨ犨t҈t㦨 ç 㦨 g ç g g è g ÷ø çè g ÷ø è ø b㡰 ᨨ 矄鼀  �    � ᨨ ᨨᆠ�ᨨ 矄   q 黨 q.和ᨨ h҈㦨

u 矄�  q  g

h㦨

u 矄�  黨° - q㡰 u  ᆠᨨ矄  q = g g

  ᆠᆠ�ᨨ  ᨨ    �ᆠ

u 矄� q 꾀矄ᨨR㦨 g

 ᨨ ᆠᆠ�ᨨ  ᨨ    �ᆠ �矄 犨泐矄 �ᆠ ᨨ犨 矄 ᨨ���  p  �ᆠ�矄  꾀t㦨�ᆠ�矄 a㡰 t㦨 p b㡰  ᨨ   �矄 ᆠ ᆠᨨ  �矄 ᨨ  ᨨ盐  ᨨ    ��ᆠ    ᨨ a

h҈h㦨

r a t 㡰 = ax $� + a y $ = - p  ᲼a ᆠᨨ矄 pt $� + b 矄� pt $ 桌 r 㦨p᲼ x�$ + y $ 桌 = - p  r t 㡰

Topic-3 : Projectile Motion ҈

g

 



㡰 矄� � � ᆠ� ᨨ ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 ᨨ ᨨ� ᨨ  鼀ᨨ�ᨨ  犨  mvx㦨mu졔muᆠᨨ矄

u  ᨨ �ᆠ 鼀ᨨ�ᨨ

vx =

h ҈  gT  Þ T = g   R �矄   ᨨ� ᨨ  �矄 ᆠ   泐   ᨨ 泐 ҈ R = v xT + 㡰 T 㡰 ᨨ ᨨ� ᨨ  鼀ᨨ�ᨨ 㡰 



҈

u  矄�  q u  ᆠᨨ矄 q 맔 g g

u  u  矄� q ᆠᨨ矄 q㡰  R 㦨  ҈ g ҈ ᨨR㦨҈h҈h 㡰 졠  � ᆠ�   �鼀ᨨ  ��  㡰�矄��  泐 u 矄� q T= g ᆠᨨ矄 a 和盐矄�盐� �   盐矄 犨 � 㡰 矄� ҈�°㡰 矄� ҈�° T= = g ᆠᨨ矄 ° ҈ ᆠᨨ矄° ҈  �矄 ᆠ和 = ᆠᨨ矄҈�°㡰T - g 矄� ° T 㡰  㦨

�



h = +



鼀⏌矄 q 㦨҈�

 �矄�

� �ᆠᨨ矄

a 㦨

WWW.JEEBOOKS.IN

PS-19

Motion in a Plane   矄� ҈�° æ҈ ö ҈矄� ҈�° = ᆠᨨ矄҈�°㡰 - ç ´ ҈矄� °÷ ø ҈ᆠᨨ矄  ° ҈ ҈ᆠᨨ矄 ° è 

黨

҈  - ҈ ; ҈黨�鼀 ; ᆠ鼀  b㡰 ҈鼀⏌矄

q

� ᨨ

҈

)

泐㦨  �  ҈  鼀 ⏌ 矄 = ҈  � 

 ᔴ �ᆠᆠ�ᨨ   㦨

� +҈ + 䰘� ҈   �㡰 

҈ᆠᨨ矄 q ᨨ鼀 ��盐 盐矄� � �㡰㡰

=

䰘

=

҈  �  =    Þq= ҈�° �

(

҈    ҈ᆠᨨ矄҈�

҈҈

) = 鼀

㡰 꾀矄犨├ ᨨ犨 �  =

盐  矄� q �

 꾀㦨p  \꾀µ ᨨ꾀µ 盐 

�ᆠᨨᆠ�泐 � ��㡰�㦨uy t졔 Þ uy맔졔

\

 q =

҈  gt 

҈  ҈㡰맔 

ᨨ �㦨uy ᨨ uy㦨

uy ux

=

� 䰘 =  

Þ 꾀 �q㦨 ҈

䰘 

q

u⏌a t҈



q

u⏌a  t

u

q

u⏌a m

t u

q tn un

ᨨ �矄ᆠ鼀  꾀� ᨨᆠ�泐 = ᨨ�鼀├

u 矄� q

�鼀ᨨ  ��  T = g

\



鼀

ᨨ 盐 = ҈ = ҈ 鼀矄 -҈ �� ᨨ 犨꾀 ҈ � 졠꾀㡰  㦨 졠꾀  q  盐  ᆠᨨ矄 q ҈ ҈ ´ ҈ = - ´ =  鼀 ҈ ҈  ҈ ´ ҈ ´ ´   (4)  u҈ u u    ᨨ� ᨨ  ᨨᆠ�泐ᨨ    ᨨᆠ�矄 t҈ t t  �鼀├ 矄矄 ᨨ犨 �

��盐 u

꾀҈ 盐҈ é ҈ ù ҈ = = = 꾀  盐  êë  úû ҈ ᆠ㡰 ᨨ鼀 ⼄盐矄�ᨨ  ᨨ� ᨨ  ᨨᆠ�泐 � ��㡰  ux = = 鼀⏌矄 



盐  矄�  q �  ´ � � ´  ´ ҈ \ 盐  = = = ҈   矄� q æ ҈ ö ç ÷ è ø

꾀 㦨҈矄ᆠ ᨨ� ᨨ ᆠᨨ鼀ᨨ  ᨨ ᨨᆠ�泐x㦨� 鼀⏌矄 �ᆠ ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐

 q=

犨

㝐 �鼀盐鼀 �� 㦨

v泐㦨҈ᆠᨨ矄 㦨 �  鼀⏌矄

  + 泐

� 鼀

꾀矄  �矄 ᨨᆠ      � �  ᨨ   ᨨ� ᨨ    ᨨ  �㦨 ҈ = � 鼀 ᨨ ҈㦨Þ  =  Q  �㦨鼀졔鼀㦨҈鼀㡰

ᨨ� ᨨ  ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐 x㦨҈ᆠᨨ矄 㦨�鼀⏌矄 �ᆠ ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐

Þ =

b㡰 졠

 � ҈ - � 㡰

(

… ��㡰





�ᆠᨨ矄q



… �㡰

҈ y = t - ҈t  㡰  ᨨ鼀 �㡰  ��㡰y㦨x�x

=



r

b㡰 ᨨ鼀⼄盐�ᨨ  v = �ˆ +  ˆ Þx㦨t

䰘 = �鼀 ⏌ 矄 

ᨨ�� 盐ᨨ q盐ᨨ T犨�ᆠ  �犨�  盐 ᨨ  u \ ᨨ�鼀├ 㦨t҈졔t졔t졔 t t t ta = t҈ + ҈ + ҈ +  = ҈ = ҈  ҈ a a a - ҈㡰 ҈a

ᨨ �矄ᆠ鼀 㦨盐҈҈졔盐졔盐 졔

u҈ t҈ u҈ t҈ ut u t a  +    +  = ҈ ҈ = ҈҈ ҈ a a a a ҈ -  a - ҈㡰 a ᨨ �矄ᆠ鼀  \ 꾀� ᨨᆠ�泐 = ᨨ�鼀 u҈t҈a  a - ҈㡰 u҈a ´ =  =  a +҈ t҈a a - ҈㡰 = u҈t҈ +

WWW.JEEBOOKS.IN

EBD_8341 PS-20

Physics 犨 a㦨҈�鼀⏌矄 ᨨ uᆠᨨ矄 q 㡰t㦨졔䰘�t  ��㡰 ���㡰 ᨨ� ᨨ  ᆠᨨ鼀ᨨ   ᨨ ᨨᆠ�泐 ᨨ 矄ᨨ  㦨 �ᆠ ᆠᨨ鼀ᨨ   矄 ᨨᆠ�泐 ᆠᨨ �矄 � ᆠ�    �  犨� ᨨ� ᨨ  \ uᆠᨨ矄 q 㡰㦨gt u矄� q 㡰  ���㡰  ��    矄�  �矄 犨�  gt  u 矄� q  ᆠ盐矄   矄ᨨ �矄� �矄 ᨨ犨 犨 鼀ᨨ�ᨨ \gt>u矄� q ᔼ 盐犨 鼀ᨨ�ᨨ  盐矄� q > gt㡰 㝐盐�泐� �⼄盐�ᨨ  ���㡰犨� t uᆠᨨ矄 q 㡰t졔 u矄� q 㡰t㦨҈ t  �㡰 ᨨ犨 �㡰 ��㡰 �㡰��矄�t�㦨ᨨt㦨҈矄 和盐矄�盐� �t㦨҈矄�  �㡰  ��㡰犨� u矄� q 㦨�鼀⏌矄ᨨuy㦨�鼀⏌矄  uᆠᨨ矄 q 㦨䰘�鼀⏌矄 r ᨨ ux㦨䰘�鼀⏌矄 \ u = u x $� + u y $

꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  � ᨨᆠ�泐㦨  ҈ u҈a ᨨ ҈ =  �㡰 a +҈

u҈ ´ t҈ = u҈  ��㡰 t҈ ᨨ鼀⼄盐�ᨨ  �㡰  ��㡰 a㦨a졔ᨨaa㦨  = ᨨ a㦨ᨨ a =  ҈ �㡰 u㦨҈鼀⏌矄q㦨 盐泐 盐㦨҈鼀⏌矄 盐矄� q 㦨� 鼀⏌矄

V҈ =

r

 盐 盐ᆠᨨ矄q 㦨�鼀⏌矄 \ ux㦨uᆠᨨ矄q㦨҈맔ᆠᨨ矄 㦨�鼀⏌矄  uy㦨u矄� q㦨҈맔矄�  㦨 �  鼀⏌矄 졠

´�  = = 矄 g ҈  a   ᆠᆠ�ᨨ  ᨨ �  ҈   ҈҈� = u xt - at  ҈ Þ ҈҈� = � ´  - ´ a ´ 㡰   a Þ = �  - ҈҈� = � - ҈҈� = 䰘�   \ a = 䰘� ´ = � 鼀⏌矄   T盐㡰 쟼㦨쟼졔⧤쟼㦨ᔴᨨ 矄  꾀 ᨨ⧤쟼�矄鼀� �鼀盐鼀  쟼�矄 鼀 �鼀盐鼀和� ᆠ ⧤쟼�矄鼀� �鼀盐鼀矄ᨨ矄 �矄矄ᨨ鼀� �鼀盐鼀 ἘtἘ �鼀 犨 �ᆠ  矄ᨨ  �矄 ᨨᆠ r q      � 犨 �ᆠ    ᨨᆠ�泐ᆠᨨ u  鼀├矄 犨� ᨨ� ᨨ  \

҈ ҈

҈�

t=

u y

y

v x 㦨u ᆠᨨ矄 q

u u矄� q

q

졠 u ᆠᨨ矄 q

gtu 矄� q 㦨᲼vy 桌 ҈�鼀

� v

x

꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ 犨  ᨨᨨ犨� � ᆠᨨ ��ᨨ 矄 �㡰 �ᆠ �矄ᆠ鼀 ᨨ 矄ᨨ �矄҈�鼀 ҈ \ ҈�㦨 u矄� q 㡰t gt  犨 �㦨҈鼀⏌矄  �㡰 ᨨ u矄� q 㡰t㦨҈�졔� t  ��㡰 ᨨ� ᨨ  �矄ᆠ鼀  ᨨ 矄ᨨ  㦨졔 �矄ᆠ鼀 ᨨ ᨨᆠA ҈  \ uᆠᨨ矄 q 㡰t㦨졔 at 

ᨨ u = 䰘� $� + � $ 㡰 鼀⏌矄 꾀   �鼀 犨 �ᆠ   矄ᨨ  �矄  ᨨᆠ t 㦨 ҈矄 㡰  � ᨨᆠ�泐ᨨ   �ᆠ 犨�  矄ᆠ ᨨ  ᨨ �矄uᨨ犨 �ᨨᆠ�泐� x y㜠 �ᆠ�ᨨ

ux   uy 矄ᆠ�泐 和� ᆠ   �矄 ᨨ ᨨᆠ�泐ᨨ    ᨨ  �    y㜠 �ᆠ�ᨨ    ᨨ  �矄 �矄   �ᆠ ᨨᆠ�泐 ᨨ    �ᆠ 犨� 矄ᆠ ᨨ �ᨨ盐  矄ᨨ

├� ��鼀矄犨ᨨ Y㜠 �ᆠ�ᨨ 鼀ᨨ�ᨨ

uy㦨졔u矄� a ay㦨gᆠᨨ矄q sy㦨 ᆠ��泐�矄├ � �鼀 �ᆠᆠᨨ鼀矄 ᆠ├ᨨ ᨨ 㡰 ty㦨t ҈ ҈  sy㦨 u y t + a y t Þ 㦨 u矄� a㡰t g ᆠᨨ矄 q ´ t    u 矄� a Þ t㦨ᨨt㦨 g ᆠᨨ矄 q

├� ��鼀矄犨ᨨ X㜠 �ᆠ�ᨨ 鼀ᨨ�ᨨ

ux㦨졔uᆠᨨ矄a ; ax㦨tx㦨tsx㦨sx

҈ 

 sx㦨 u xt + a xt  Þ sx㦨uᆠᨨ矄a맔

u 矄� a u  矄� a = g ᆠᨨ矄 q g ᆠᨨ矄 q

æ u 矄� a ö b㡰  �矄 ᆠ 泐 ᨨ � �鼀 ç ÷ è g ᆠᨨ矄 q ø 矄 ᨨ盐 ⼄盐ᨨ  �ᨨ  �ᆠ ᨨ ᨨ矄 ᨨ  �ᨨ盐  ᨨ 矄 ᨨ� ᨨ  �矄ᆠ鼀  ᨨ  ᨨ   矄 ᨨ  ᨨ  �鼀ᨨ ᨨᆠ�ᨨ ᨨ �ᆠ U   ᨨ 鼀ᨨ�ᨨ ᨨ ᨨ 犨� 矄ᆠᨨ�ᨨ盐  ux㦨U 錐 ax㦨g矄� q 錐t y㦨

u 矄� a -u  矄� a 錐 sx㦨 g ᆠᨨ矄 q g ᆠᨨ矄 q

҈  sx㦨 u xt + axt 

WWW.JEEBOOKS.IN

PS-21

Motion in a Plane

æ u 矄� a ö ҈ -u  矄� a æ u 矄� a ö = -U ç - g 矄� q ç g ᆠᨨ矄 q è g ᆠᨨ矄 q ø÷  è g ᆠᨨ矄 q ø÷

ᨨ鼀矄矄鼀hᨨ犨  ᨨ鼀C ᨨ ᨨ� ᨨ 鼀ᨨ�ᨨ QM㦨᲼҈ᆠᨨ矄 桌t QM㦨�t



ᨨ�ᆠ鼀ᨨ�ᨨ vy㦨҈矄�  㦨�  錐ay㦨g sy㦨y졔҈錐ty 㦨t

u ᆠᨨ矄 a + q㡰 ᆠᨨ矄 q

� 盐矄ᆠᨨ� � �ᨨ� P 泐 ᨨᨨ犨 �    ACP ABP.  t҈㦨 �鼀├ 泐 �矄盐� ᆠ � �P t㦨 �鼀├ 泐矄ᆠᨨ 盐� ᆠ � �P y u B ᨨ   ABP  �R㦨 uᆠᨨ矄 㡰t  u  �R㦨 u҈㡰 A C ᨨ   ACP h 和ᨨ� �⼄  �㡰犨�U㦨

҈

\

ut = ut҈ 

ᨨ t㦨t҈  �㡰 ��  ᨨ   ABP

ᨨ犨vy㦨�  졔gt ҈   sy 㡰㦨uy t졔 ay t  ҈  Þ y졔҈㦨 �  t + gt  ҈  ᨨ犨盐� �盐ᨨ  y = gt � ⼄  �㡰   ҈  ҈ 矄ᆠ gt + ҈ = �  t + gt  Þ t㦨    �矄 ᆠ 犨  ᨨ ᨨ犨矄

P

҈鼀

㡰

ᨨ ᨨ

-�  ´ t

\

㦨҈䰘鼀  ��㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 盐� � ᆠᨨ�矄�ᨨ  ᨨ    鼀矄矄矄  M㡰 �    ᨨ� ᨨ  �ᆠ�ᨨ

 ᨨᆠ�泐 ᨨ  ᆠᨨ鼀�   鼀矄矄 ᨨ � ᨨ� ᨨ  㦨 v x m맔҈m҈ᆠᨨ矄 㦨m맔 vx Þ ҈m҈m㦨m맔vx Þ vx㦨 和� ᆠ  ᨨ� ᨨ 鼀ᨨ鼀 盐鼀ᆠᨨ鼀矄ᨨ盐ᨨ ᨨ  ᆠᨨ鼀� �ᨨ ᨨ 鼀矄矄矄犨� ᨨ�ᆠ泐 ᨨ犨 犨 矄 E  \ 쟼㦨㝐㦨҈t㦨҈맔 㦨҈҈�䰘鼀 

-u ´ t ҈  ҈  + gt = gt҈   

҈t҈ ҈t҈ =    -҈�t + ҈t = ҈҈ ᨨ - t + t = t҈ +

-  ´ t҈ 㡰 +  t҈ 㡰 = t҈ ᨨ -t҈ +  ´ 㡰t҈ = t҈ ᨨ t҈ = t҈ ᨨ t҈㦨҈矄ᆠ \ t㦨t҈㦨矄ᆠ ᨨ犨R㦨ut҈ ᨨ ACP

 ��㡰  ���㡰

u  矄� q 黨㡰  矄�  ´ �° =  㦨 � 鼀 g 黨 �矄 ᆠ 犨    ᨨ� 矄 ᨨ   ᨨ犨 ᨨ  �ᆠ矄 �矄 矄ᨨ �鼀 �矄鼀 矄  �ᆠ矄矄 ᨨ盐 ᆠᨨ� 鼀� 犨泐 犨  A   B   � 鼀 �鼀盐鼀 ��  H 㦨

 �㡰

u  矄�  q 黨㡰 矄� �°㡰 㦨 㦨҈�鼀 g  ´ 黨

ᨨ

ᨨ

R = �  ´҈ = �  鼀

҈

҈  gt҈  ᨨ  ACP  ҈   = ´҈ ´ ҈㡰 = � 鼀 

҈䰘

u ᆠᨨ矄 �° = 黨

y㜠ᆠᨨᨨ � ᨨ P㦨҈h㦨҈�㦨�鼀  㡰

�鼀� 犨   �� �矄㦨 tt҈㡰 㦨 ҈㡰㦨҈矄ᆠᨨ

҈  y㦨 gt  ��㡰  ᨨᆠ�泐 �  �ᆠ �ᆠ�ᨨ

vy㦨uy졔ay t㦨gt ���㡰

 鼀⏌矄

꾀泐� �ᆠᨨ 矄�ᨨ ᨨ � 鼀ᨨ鼀 盐鼀 ᨨ� ᨨ ᆠᨨ�矄�ᨨ

m҈ u ᆠᨨ矄 �°㡰 - m u ᆠᨨ矄 �°㡰 = mv - m҈ u ᆠᨨ矄 �°㡰

��㡰 ᔴᨨᨨ � 矄ᨨ ᨨ� P㦨 Ry㡰 = �  鼀�鼀㡰 �㡰 t �鼀├  ᨨᆠᨨ�矄�ᨨ 

�  � ᨨ�  ᨨ ᆠᨨ�矄�ᨨ  ᨨᆠ矄  ᨨ犨  ᨨ鼀꾀  ᔴ 盐  ᨨ � ᨨ�ᆠ  矄 ᨨ鼀矄矄mhᨨ犨 hᨨ� ᨨ y ᨨ鼀A ᨨ ᨨ� ᨨ  鼀ᨨ�ᨨ

㝐㦨VA맔t㦨҈t �㡰 ᨨ �ᆠ 鼀ᨨ�ᨨ

uy㦨錐sy㦨y錐ay㦨g錐ty㦨t \

  � R 㦨

쟼ᆠ  �ᆠ 矄   矄鼀 矄  ᨨ  黨 鼀⏌矄  ᨨ� ᨨ  ᨨᆠ�泐 ᨨ  ᆠ  �ᆠ �矄 矄鼀 �

꾀��  h =

\ �㡰

 �㡰

BD㦨PM졔MQ㦨҈t졔�t㦨҈�t㦨҈�맔

҈ h = - u 矄� °㡰t + gt  ҈  h = gt҈  ��  ᨨ   ACP

 㡰



x

R

 �㡰

맔黨맔

҈ ҈ ҈   ´ 黨 ´ +  V 㦨  ´ 黨 ´   

\ V㦨 �ᆠQ �矄  矄   ᆠᨨ�矄�ᨨ    犨�  �ᆠ泐 ᨨ犨 犨 矄   鼀� 犨泐

�鼀├ 㦨

H  ´ ҈� 㦨 㦨�矄 g 黨

Topic-4 : Relative Velocity in Two Dimensions & Uniform Circular Motion ҈

㡰 R㦨҈鼀

w=

p  p = = ҈�  ⏌矄 T 

WWW.JEEBOOKS.IN

EBD_8341 PS-22

Physics

꾀ᆠᆠ�ᨨ  ᨨ   � ᨨ   ᆠᨨᆠ├ 矄ᆠᨨ Ἐ矄  

a = w  R = ҈�㡰 ҈㡰 = ҈҈ = ҈҈ ´ ҈- 鼀⏌矄







 ᆠ � ᆠᆠ�ᨨ  �矄 ᨨ   ᨨ  ᨨ ҈ 

㡰 ��  矄�盐�ᨨ  �矄 矄 ᨨ犨  �    ��鼀  vr    ᨨᆠ�泐ᨨ �  ᨨ



q

 vr

vr

p - q㡰

vr



�

- ҈

vᆠ 㦨 b 졔҈㡰v

vᆠ 㦨v

v

ᔴ  � �  ᨨᆠ�泐

 D  = ҈ +   + ҈   ᆠᨨ矄 ( p  q )

␔  ᆠ�矄鼀ᨨ� �犨�  矄 v v  ° = r  �㡰 v ␔  ᆠ�矄 鼀ᨨ� �犨� 矄  ҈ + b㡰v 

vr b + ҈㡰v �� � � �㡰泐 ��㡰犨�  �° =

㦨矄�

ᆠ㡰  矄� q =

 ��㡰 䰘

b㡰

u  ҈ = = v  

 q 盐 

ˆ ᨨ 㡰

B rBA

҈ 

㦨҈鼀⏌矄 ᆠ㡰 和  V 㦨 ᆠᨨ 矄  ᨨ鼀 ⼄盐矄�ᨨ 㡰 ᔴ � ᆠᆠ�ᨨ 

V r ra 㦨 ᆠᨨ 矄   ᆠ �  ᆠ㡰 ᆠᨨᆠ泐 矄ᆠ�矄 �ᨨ  犨

ᆠᆠ�ᨨ     �盐矄 r b㡰 和 ᨨ矄 ᨨ盐 ᆠᨨ矄ᨨ 矄 ᨨ vb   �ᆠ盐 ᨨ � ᨨ犨 ® vr d d \t= =  vb ® - vr vbr ® vb d v ᨨ t =

ᨨ

r r �ˆ + ҈� ˆ 㡰 -�ˆ - � ˆ 㡰 rBA )( · vBA ) ( t鼀� �鼀盐鼀 = =  ҈ ҈㡰  ( vrBA )

҈䰘 \t= = =  矄 ҈ ҈ ´ ҈ ҈ ҈ p p = ᆠ㡰 ᨨ鼀q㦨w㦨w w  和ᨨ ᨨ   ᆠᨨ鼀  ⼄盐 ᆠ�ᆠ

d ҈├鼀 = ҈ vb ҈ 

҈ = 

҈ � - vr

 Þ vr = ├鼀⏌ 黨

҈䰘

㡰 �鼀├ ᨨᆠᨨ矄矄 �t㦨

vsᆠᨨ矄q

vs w ҈ 꾀

� ᨨᆠ�泐

( )

w  

d vs ᆠᨨ矄 q

 d ␔

q



 꾀    = w ҈ �ˆ - w  ( � )

= w (   ҈ ) �

r

br

�ˆ 쟼矄㡰

A r ˆ vA = � + � ˆ ├鼀⏌  r vB = -҈�ˆ㡰 ├鼀⏌  rBA = �ˆ + ҈� ˆ 㡰 ├鼀 r r r vBA = vB - v A = -҈�ˆ - �ˆ - ��ˆ = �ˆ - � ˆ

�

r

(Q ҈  =    ) = 

a 㦨

ᨨq㦨 犨�  矄ᆠ ᨨ ᨨ犨 㦨黨 졔 㦨҈ 

q 

㦨 맔҈㡰맔矄�  㡰㦨맔҈맔

v = b + ҈㡰v Þ b =  - ҈ = 䰘 



vr

쟼 和

ᨨ�鼀ᨨ鼀� �鼀盐鼀ᆠᨨ矄q㦨鼀 �鼀盐鼀�q㦨  ᆠ矄犨�鼀鼀矄 ᨨ盐 矄犨�鼀 盐 ᨨ 

WWW.JEEBOOKS.IN

PS-23

Laws of Motion

Laws of Motion

4

Topic-1 : Ist, IInd & IIIrd Laws of Motion ҈

㡰 ෌�

r F = k v y �ˆ + vx ˆ 㡰 \ Fx = kv y �ˆ Fy = kv x ˆ mdvx dv k = kv y Þ x = v y dt dt m 和�鼀�泐

dv y





dv y

dt

=

\ = �

꾀 㦨㦨鼀盐  h =

k v m x 

䰘

dp d mv㡰 æ dm ö F= = = vç  �㡰 ÷ dt dt è dt ø dM t 㡰 = bv  t 㡰 ␔  ��   ��㡰 dt

盐矄 ᨨ    矄� æ dm ö   F = -v ç ÷ = -v bv 㡰 = -bv ᲼矄� � �㡰  ��㡰桌 dt è ø -bv Þ F = M t 㡰 a = -bv Þ a = M t 㡰



H

g졔kv 㡰㦨a ᆠᆠ�ᨨ 㡰

u

r F = mkv  - mg  Q mg mkvᆠ





 

mV mV  = 鼀    L  nr 㡰 L   nr V 鼀 㡰 ᨨ鼀 ⼄盐矄�ᨨ  㝐矄矄ᨨ ᨨ 泐m㦨�├� ᨨᆠ�泐t㦨 u㦨 �ˆ -  ˆ㡰 鼀⏌矄 ᨨᆠ�泐t㦨҈矄 v㦨졔 ˆ 鼀⏌矄 ᨨᆠF㦨䁸

꾀ᆠᆠ�ᨨ a㦨

ᨨᨨ矄�ᨨ ᆠ  ᨨ 㡰

r r F a= = -᲼kv  + g 桌 m dv ö æ dv Þ v× = -᲼kv  + g 桌 çèQ a = v ÷ø dh dh h  v × dv  ҈ Þò  = ò dh  éëkv  + g ùû = - h Þ u k u kv + g   ҈ é ku + g ù  ê Þ ú= h k ë g û 㡰  ᆠᆠ�ᨨ

 㦨㦨 �졔g㡰  �鼀⼄盐� ᨨ�矄ᨨ�矄  �  㦨㡰矄ᨨ   -  = ò  ò ᲼ ᨨ鼀 㦨桌   � + g 



é  ù ├    = ├  Þ  = ├ [ ] ê ú  Þ = Þ =  ò ò êë  úû   ├   㡰 㦨 㡰 ᨨ鼀 㦨   㡰 鼀       = ò ᔼ �� � ᨨ  矄� 矄 ò  鼀 ҈ \   µ ᔼ   =  鼀 b㡰 和ᆠ 犨    矄盐ᨨ矄 ᨨ 鼀ᨨ�ᨨ  ᨨ   矄 �矄   꾀� ᨨᆠ  � ᆠ  泐 ᆠ  矄盐ᨨ

F=

黨



u P =  f

盐犨  �ᆠ�ᨨ  �矄 ᨨ矄��   ᨨ犨 犨  �ᆠ�ᨨ  �矄

�� b㡰 ᨨ鼀 犨ᨨ 矄 矄ᆠᨨ  犨  = = ├  ᔼ �� � ᨨ  矄� 矄 犨 � 

b㡰 ᨨ鼀   犨ᨨ Ἐ矄 矄ᆠᨨ 犨

v㦨

㡰 㦨盐 � ᨨ㦨 u  -  gh  㝐ᨨ鼀 盐鼀㦨鼀 = m u -  gh

v = x Þ ò v y dv y = ò v x dvx dvx v y v y = v x + C v y - v x = ᆠᨨ 矄  k r r v ´ a = v x �ˆ + v y ˆ 㡰 ´ v y �ˆ + vx ˆ 㡰 m k     k  = vx kˆ - v y kˆ㡰 = vx - v y 㡰 kˆ = ᆠᨨ 矄  m m



æ g  ö  -҈ ç ç � ÷÷ g� è ø

҈

҈

v - u  ˆ - �ˆ -  ˆ 㡰 -�ˆ +  ˆ 㦨 鼀⏌矄 㦨 ҈ � t

ᨨᆠF㦨ma -�ˆ +  ˆ 㡰 㦨 � ´ = -�ˆ +  ˆ 㡰 N � ur 㡰 ෌� 鼀ᨨ鼀 盐鼀 p t 㡰 = A ᲼�$ ᆠᨨ矄 kt 㡰 - $ 矄� kt 㡰桌

ur ur d p = Ak ᲼-$� 矄� kt 㡰 - $ ᆠᨨ矄 kt 㡰桌 꾀  ᨨᆠ F = dt ur ur r r  F  P =  盐 F  p = Fp ᆠᨨ矄 q \ ᆠᨨ矄 q 㦨Þ q 㦨黨   ᆠ �犨   ᨨᆠ鼀ᨨ鼀 盐鼀q㦨黨 ҈҈ �㡰 꾀 盐    F  t �  ��矄   �鼀盐矄 �鼀  ᨨ   ᨨ 泐

鼀� �盐 ᨨ ᨨ�鼀盐矄ᨨ  ᨨᆠᨨ  ᨨ 泐 ᨨ鼀 t㦨Ҙ矄ᨨt㦨҈Ҙ矄 㦨 BCDFEB㡰 㦨ᨨ BCFEB졔CDFC

WWW.JEEBOOKS.IN

EBD_8341 PS-24

Physics F � 㡰

 C

    A

B

҈

҈

҈

҈�

 

D

F

E





 ҈ ҈ ҈ ҈ T

҈ ҈ - - 㦨  + 㡰 ´  ´ ҈ 졔 ´ ҈ ´  ´ ҈   ᆠ�ᨨ

㦨҈졔㦨�矄 矄  ᨨ犨 鼀ᨨ�ᨨ ᨨ ᨨᆠ├ �矄 盐 ᨨ   盐矄 �矄矄  ᨨ犨

ᆠ├犨  ᨨ 盐ᨨ矄盐ᨨ盐 � �� 盐矄 � � ᆠ├犨 矄 ᨨᆠ├   盐矄 �矄矄  ᨨ犨

ᆠ├犨 矄 �矄 ᆠ�ᨨ    ᨨᆠ├ 鼀ᨨ� � ᨨ犨  �矄 ᆠ�ᨨ  쟼 盐矄�矄矄

�矄   ᨨ鼀 ᨨ ├矄ᆠ�   꾀ᆠ�ᨨ

矄 ᆠᨨ � 矄 犨 b 㡰쟼 �矄 ᆠᆠ  鼀   ᆠᆠ

ᨨ  � � 鼀 쟼  �矄 ᨨ� � ᨨ盐   矄盐    �矄 ᨨ� � ᨨ盐 �矄 ᨨ犨  �矄 b㡰 ᔼ �矄 矄� ᨨ盐  泐ᨨᆠ    ᨨ 盐矄  � ᨨ   �ᨨ盐  �矄�矄ᆠ盐矄  ᨨ鼀ᆠ�ᨨ �  ᆠ矄 ᨨ 盐� ��矄矄矄矄ᆠᨨ鼀 泐盐矄 � � 㦨m 㡰  ᨨ   �ᆠ�ᨨ  ᨨᆠ�矄矄鼀� ᆠ矄ᨨ 盐� �

鼀� �盐 ᨨ  �ᆠ�ᨨ  ᨨᆠ  矄 ᨨ    盐ᨨ   犨ᨨ 矄盐 ᆠ矄 �  ᆠᨨ ᆠ 盐 �矄 ᨨ   ᆠ盐ᆠ   �ᨨ  ᨨ  矄鼀 㜠҈ b㡰 ᔴᨨ ᆠ 盐 ᨨ盐犨� ᨨ盐 �矄ᨨ �� �  �矄 矄 ᨨ鼀   ᆠ盐矄 ᨨ � � 犨ᨨ � ��矄 犨ᨨ Ἐ矄 �矄犨ᨨ 鼀ᨨ�ᨨ  ᨨ 泐 ᆠ�ᨨ    �矄   ⼄盐   ᨨᨨ矄� ᆠ�ᨨ 

�矄�矄犨ᨨ Ἐ矄 � 犨ᨨ 鼀ᨨ�ᨨ  Topic-2 : Motion of Connected Bodies, Pulley & Equilibrium of Forces

҈

�

 = ҈ 鼀矄 -  + ҈ + 

 矄�ᨨ     鼀�  ᨨ�  㝐矄矄ᨨ ᨨ ö æ

= ç 㝐 + ÷  è ø 㦨 ҈졔㡰맔҈㦨҈黨 =





\ 㦨҈

҈

T a T ma

T

a

T矄� q T矄� q

q Tᆠᨨ矄q

x

x

m

 �㡰

矄ᨨ F㦨T矄� q  Þ T㦨 盐� � �矄盐ᨨ  � ⼄  �㡰

F 矄� q

æ F ö ᆠᨨ矄 q ÷ è 矄� q ø m

a㦨 ç

䰘

졠  �� � � �㡰泐 ��㡰犨�



b㡰 ᨨ鼀 ��盐 ᆠᆠ�ᨨ

ᨨ 鼀矄矄m�矄 盐ᨨ  ᨨᆠT ᆠᨨ矄 q Tᆠᨨ矄 q 㦨ma T ᆠᨨ矄 q Þ a㦨 m

 ��㡰

T ᆠᨨ矄 �° ҈ = Þ F㦨҈ T 矄� �° F 㡰  ᨨᆠ ᨨ    ᨨ 㦨 ᨨᆠ ᨨ  ᨨ 졔 �ᆠ�ᨨ  ᨨᆠ Þ F㦨 ҈m졔M㡰g졔f 犨 m㦨 鼀矄矄ᨨ 矄ᨨ M㦨鼀矄矄ᨨ ᨨ f㦨 �ᆠ�ᨨ  ᨨᆠ Þ F㦨 ҈맔졔黨㡰맔黨졔Þ F㦨N Þ P㦨FV㦨맔㦨W 㡰 꾀⼄盐���盐鼀 ᨨ � 鼀� ҈ =  � 㦨 ᨨ �

F

\

㡰 ᨨ鼀  ᨨ 泐 ��鼀 Tᆠᨨ矄� 㦨҈N  �㡰 T矄� � 㦨F

b㡰 ᨨ鼀 ��盐 꾀ᆠᆠ�ᨨ  a㦨 Ra … �㡰 a  mgT = ma … ��㡰 ᨨ鼀⼄盐�ᨨ  �㡰  ��㡰 æ aö

T맔R㦨mRa㦨mR ç ÷ è Rø ᨨ T㦨ma

Þ mgma㦨ma 鼀  g Þ a= 鼀�  㡰 꾀ᆠᆠ�ᨨ  ᨨ 盐ᆠ  �  盐犨  �ᆠ�ᨨ

= 㝐҈ + 㝐  + 㝐矄矄ᨨ 鼀ᨨ



é F F x a  - x ù êQ  q ú  = m  q = m x ê ú a  - x ë û ᆠ㡰   ᨨ   矄� � �矄 ᆠ盐    矄�ᨨ  T 矄 ᨨ ᨨ ᨨ  鼀矄矄矄 m   m   ᨨ T㦨mg ␔   矄� ��矄ᆠ盐 鼀矄矄m�矄 泐 � �ᨨ 泐 �矄 ᆠᆠ�ᨨ 㦨 ᆠᆠ�ᨨ  盐ᨨ��泐㦨 g ᨨ鼀矄矄m盐矄  矄� ��矄ᆠ盐 鼀� T鼀� 矄 mgᆠ盐矄ᨨ    矄�ᨨ

ᨨ  矄� � 鼀 鼀 g \ mgmg㦨m맔a Þ = a   鼀� 鼀� 㡰 꾀⼄盐���盐鼀T㦨Mg ᨨ 盐泐 T

mg

T T

Mg

T㦨㝐�

 F

F҈㦨 m졔M㡰g

 矄盐   ᨨᆠ ᨨ 盐泐

F҈㦨 m졔M㡰g

  F㦨 F҈ + T  㦨 ᲼ m + M 㡰 + M 桌 g

WWW.JEEBOOKS.IN

PS-25

Laws of Motion 黨

ᆠ㡰   矄�ᨨ  �  ᨨ  矄� �矄 犨�  矄鼀 盐 ᨨ 矄泐鼀鼀泐

T ᆠᨨ矄q T ᆠᨨ矄q

ᨨ鼀 ��盐

㦨鼀�

q q

T T T 矄� q A

T T 矄�  q

B

T C

Ö mg mg

mg

ᨨ⼄盐���盐鼀

 mg = T ᆠᨨ矄 q + T ᆠᨨ矄 q = T ᆠᨨ矄 q \

҈

 mg =  mg 㡰 ᆠᨨ矄 q ҈ Þ q = �° \ ᆠᨨ矄 q =  矄 ᨨ鼀 矄 ᨨ犨 � ᆠ矄 㡰 ᨨ鼀矄矄m Tmg㦨 ma  �㡰 ᨨ鼀矄矄m ᔴ矄 㡰

a

mgT㦨ma  ��㡰 ᨨ鼀 �㡰  ��㡰 a㦨g⏌  ���㡰 ᔴ矄 b㡰 Tmg㦨maἘ Þ mgmg㦨maἘ ᲼Q T㦨mg桌 \ aἘ㦨g  �㡰  ᆠ ᨨ鼀⼄ ���㡰 �㡰aaἘ ҈҈

㡰 꾀ᆠᆠᨨ � � ᨨ ᆠᨨ 矄�  �ᨨ

ᨨ鼀 ��盐

m

T a mg

҈

a T

T

U Q

҈鼀

T= mg

m

a' mg

q

 q  �㡰 x졔z㦨 l �  �� �  O M ⼄盐�ᨨ  �㡰犨ᨨt dz dl = l 졔z  Þ zvM㦨 lU dt dt zö æ U U l = Þ vM㦨 U = çèQ ᆠᨨ矄 q = ÷ø l z z ⏌ l ᆠᨨ矄 q l㦨㝐矄矄ᨨ 盐 � � ᨨ 犨�├�⏌鼀 P U

mg

a҈ kx

T

x ҈ æ ҈㝐� ö 㝐� = ç ÷=   è ├ ø ├ � ├ 㝐� � ´ = ᨨ鼀⼄  �㡰҈㦨 䰘 ҈㝐 x 䰘 x �ᆠ�矄鼀 ᨨ矄��ᨨ  �矄ᨨᆠ�泐㦨꾀 꾀w 꾀 㦨  㝐� ├ x ├ = 㦨  ҈㝐 ├ ҈㝐 ҈ b㡰  ᨨ鼀 ��盐AN㦨x 㦨ᆠᨨ 矄 矄盐泐A dz B �  㡰NO㦨z  ᨨᆠ�泐ᨨ 鼀矄矄m㦨  꾀矄ᨨ dt dl A x N B =U OA㦨 l    dt Z ᨨ鼀DANO l ᨨ x㦨

F㦨mg

T

l

҈鼀

T

T   +   Þ졔㦨҈ T T a Þ 졔㦨҈졔҈ a Mg Þ ҈㦨҈ M Þ 졠�ᨨ  㡰�矄 ᆠᨨᆠ �x   矄�ᨨ ᨨ  矄� �ᆠ� � 矄   ├ 㦨㝐҈ 㝐� 㦨㝐  㝐� 㦨㝐 ҈ 졠  矄ᨨ� � 犨 � ├ 

㝐 � ├x ҈㦨  �㡰 䰘 ҈㝐 㝐� ├ ├  \ w 㦨 \ w㦨 ҈㝐 ҈㝐 㝐� ├x +  ��㡰  㦨 䰘 䰘 ᨨ҈㦨 㝐 �鼀盐鼀  矄�ᨨ ᨨ 矄� �㡰犨  ᨨ鼀 �㡰 

� ├x 㦨 䰘 ҈㝐 ├x 㝐�

\ �㦨 \ x㦨

㝐 ├ 㝐   ҈㝐�  \ x㦨x㦨 㝐 ├



m҈g 졔 l l�

҈㦨

鼀҈ 㦨҈黨├� 鼀 㦨黨├�

�㡰  矄�ᨨ T鼀� ᨨ� ᨨ ᨨ犨犨� l㦨 㜠 � 㦨�鼀 \ T 鼀҈졔ll㡰�㦨 鼀҈졔ll㡰a T㦨 鼀҈졔ll㡰 a졔g㡰 㦨᲼҈黨졔 맔�㡰桌 졔黨㡰㦨맔҈㦨 ��㡰  矄�ᨨ T Ἐ鼀� 㜠ᨨ� ᨨ 盐犨� \T Ἐ㦨᲼鼀҈졔 t맔l㡰졔m桌a졔᲼mg졔l맔l�졔m҈g桌 ᨨT Ἐ㦨᲼m҈졔 l맔l㡰졔m桌 a졔g㡰 㦨᲼҈黨졔 맔҈㡰졔黨桌᲼졔黨桌㦨�맔҈㦨�

Topic-3 : Friction ҈

㡰 ᨨ ᆠ� � mg 矄� q = f = mmg ᆠᨨ矄 q

Þ  q = m = Rᆠᨨ矄q q h

 = 䰘�  f = mgᆠᨨ矄q

R h q mg矄� q

WWW.JEEBOOKS.IN

EBD_8341 PS-26

Physics

Rᆠᨨ矄q

3 + 50  㦨졔

R

q





q

h

� 



æ ö R h = R - R ᆠᨨ矄 q = R - R ç ÷ = è �ø � R \ h = =  鼀  ᲼Q �盐矄R㦨҈鼀桌 � ᆠ㡰 꾀N㦨��졔矄�  ҈ 㦨�졔맔 㦨  f 꾀ᆠᆠ�ᨨ  a҈㦨

N ᆠᨨ矄 ��

F- f  ᆠᨨ矄 ° - ҘN = m �

矄� 

é ù  -  ´  ú ê  ´  ú 㦨҈鼀⏌矄 㦨 ê f � ê ú êë úû



矄� 

N

ᆠᨨ矄

䰘



\㦨҈㦨 b㡰 ෌� 鼀҈㦨�├�錐鼀㦨҈├�錐m㦨҈�  ᨨ鼀҈鼀҈� 㦨鼀҈ Þ� 㦨�맔  鼀   ҈� 鼀졔҈㡰�

鼀 㦨 ҈졔鼀㡰 m 鼀졔鼀㡰� 鼀졔鼀㡰� ᨨ矄a㦨 ᨨ�㦨҈� 鼀졔҈㡰҈  鼀 + ҈㡰 Þ �= 



鼀҈ 鼀҈�㦨�

҈ = 鼀 + ҈ \鼀㦨├�錐 ᆠᨨ矄 ᨨᨨ�ᨨ  㡰  b㡰  ᆠᨨ �ᆠ� 矄 ᨨ  ├� �ᆠ �ᆠ�ᨨ  犨    ᨨᆠ     � ᆠ�  ҈ ҈ö æ m =  q ç҈ -  ÷ Þ m = ҈ -   Q q㦨� 㡰 è ø

b㡰 m 鼀� �鼀盐鼀ᆠᨨ �ᆠ� ᨨ  �ᆠ�ᨨ

m鼀�ᆠᨨ矄q

��

N㦨��矄� 

҈ 㦨 

㦨�맔



m�矄� q

F - f é ᆠᨨ矄 ° -  ´  ù =ê a㦨 ú 㦨҈鼀⏌矄 m � ë û  ᨨ犨aa҈㦨҈҈㦨鼀⏌矄 b㡰 ├� � 꾀졔㡰矄矄泐矄鼀 Fm M졔m㡰g㦨 M졔m㡰a F  m M + m㡰 g Þa㦨 M + m㡰

�

꾀 ⼄盐���盐鼀 鼀矄矄 ᨨ矄 ᨨ 鼀ᨨ 矄ᨨ 鼀�矄� q㦨m鼀�ᆠᨨ矄q

\ μ 鼀� =  θ



F - 㡰 ´҈ æ F -  ö =ç ÷  �㡰  è  ø 盐a鼀 㦨m�㦨맔҈㦨

㡰









҈

꾀矄矄盐鼀� � ᨨ    ᨨᆠ├矄  矄�ᨨ 泐 㦨 f҈㦨 f㦨҈졔㦨҈

F - \ =  Þ 㦨҈  ҈ ├�





a=

 µ 㦨

µ鼀�ᆠᨨ矄q

㡰 

黨

ᔴᨨ 矄� � �   犨ᨨ ᨨᆠ├矄 矄 ᨨ  矄泐矄鼀   盐 ᨨ ⼄盐���盐鼀f㦨҈ 㡰 f 㦨 Ҙ M 졔 m㡰 g

f Ҙ M + m㡰 g = = Ҙg M +m M + m㡰 㦨 � 맔 ҈ 㦨 � 鼀矄



҈

a=

졔鼀�矄� �q







f



�

鼀�矄� � 㦨

҈

㦨  � 

᲼Q鼀 = ҈├� � = 黨 鼀 矄 - 桌 m鼀�ᆠᨨ矄q㦨맔鼀�맔

҈

 졔鼀�矄� q 㦨졔m鼀�ᆠᨨ矄q

=  ´ � 

ᔼ �� 鼀ᨨ鼀 盐鼀 �V V = = M + m㡰 ҈� 

m㦨�� n

M㦨҈├� 

v  u 㦨 as   u 㦨 as u 㦨 as 

æ �v ö ç ÷ =  ´ � ´  è ҈� ø

WWW.JEEBOOKS.IN

PS-27

Laws of Motion 和ᨨ� � 犨 �  v = ҈  졠ᆠ � � ᨨ鼀 ��  H

V = ҈

҈

mg

x 

Þ

҈



mgᆠᨨ矄q

P

 mg矄� q

q

mgᆠᨨ矄q

f mg

m q

y

x㦨᠀҈

҈

x ҈ = m   㡰 ᨨᆠᨨ  �ᆠ�ᨨ  ᨨ�   ҈ �ᆠ�ᨨ = 㝐 矄� q  ҈ 㦨 㝐 矄� 黨° ᲼ q㦨黨 桌  㝐 㦨  ᆠ㡰 㝐� �鼀盐鼀 ᨨᆠᨨ A 㦨 �ᆠ�ᨨ  ᨨᆠ 犨    矄盐 ᆠ矄 㦨҈N 꾀

N

q

q

ᨨ犨 y =

҈҈

q

mg矄� q

dy x  =  q㦨m 㦨 ᨨ鼀⼄盐矄�ᨨ 㡰  dx Q ᔴᨨ �ᆠ� ᨨ  �ᆠ�ᨨ m㦨� � =

f

P

 gH

҈  =  ´҈ ´ H ҈ H㦨鼀㦨├鼀 㡰 꾀�鼀�� �⼄盐���盐鼀 m㦨 q

\

N

├� �├�

 和鼀ᨨᨨ  

␔  P㦨mg 矄� qf㦨 ␔   ᨨᆠP�矄� ᆠ矄  盐  ᨨᆠ├ 矄  ᆠ泐 ᨨ 鼀ᨨ 盐犨 矄 ᨨ �   � ᆠ�     ᆠ �ᆠ�ᨨ  ᨨᆠ ᆠ矄 ᨨ犨 犨 矄 ᨨ �   � ᆠ�  ⼄盐���盐鼀P㦨f졔mg 矄� q Þ f = P  mg 矄� q ᨨ犨矄P� ᆠ矄矄f� ᆠ矄矄� 泐犨P  ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄   矄�盐�ᨨ  b㡰 㝐 �鼀盐鼀  � ᨨ ᨨ  矄�    ᨨᆠ├  � ᨨ f � ᆠ� �ᨨ 㦨 �ᨨ ᨨ矄 졠 ҈� ᆠ q

�  -҈ m  =  -҈  = ° ᨨ   ᨨᆠ├ ᨨᨨ   ᆠᨨ ��ᨨ  ᨨ    ᨨᆠ├ 矄   矄 ᨨ犨  �    ��盐





ᆠ鼀

  ҈

m= 



q

� ᆠ鼀  PM ҈ ⏌  = = = OM ҈� ⏌  䰘� ᆠ鼀  和ᨨq  ᨨ鼀 �矄犨ᆠ ᆠᨨ ᆠ盐   ᨨᆠ├犨� ᨨ矄矄 �ᨨ � ᆠ� �ᨨ ᔴ泐 ᨨᆠ├犨� 鼀� 矄ᨨ   盐ᨨᆠ�  �q  

�犨�ᨨ ҈䰘 㡰 和� ᆠ ᨨᆠ├�矄 ᨨ鼀ᨨ� � ᨨ犨  ᨨ 鼀 �鼀盐鼀 N ᨨᆠ F �    ᨨ Fᆠᨨ矄 㦨f㦨ҘN ᨨ� ᨨ   �ᆠ�ᨨ 㡰 F ᆠᨨ矄ᨨ ᨨ�ᆠ⼄盐���盐鼀 ᨨ  mg ᨨ   ᨨᆠ├ f N㦨鼀�졔F矄�  F \ Fᆠᨨ矄 㦨m㦨Ҙ F矄� ᨨ ᲼F矄�  졔mg桌 ᔼ  D POM   q =

҈

҈ ҈

 ᨨ 鼀 �鼀盐鼀 ᆠᆠ�ᨨ

҈ = 鼀 ⏌ 矄  a鼀 㦨 ├�  ᆠ鼀 �鼀盐鼀 ᨨᆠ 鼀 㦨ᨨ鼀矄矄맔a鼀 㦨黨맔㦨䰘 b㡰 ෌  㡰 ᆠᨨᆠ泐 ��ᆠ矄   ᆠᆠ�ᨨ 㜠�鼀 �  ᨨ   ᨨᆠ├ 㡰 ␔    ᨨ 泐 矄 鼀 �鼀盐鼀 矄   

´  ´ ҈ m mg �   = =   Þ F㦨 㦨 ᆠᨨ矄 ° - m 矄� ° ҈ ҈  ҈ 

҈

m =  =  �° ҈�

\ 㦨鼀 㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ    q > m 矄ᨨ ᨨᆠ├ 矄    ᆠ泐 ᨨ 鼀ᨨ ᨨ犨    � ᆠ�  ᨨᆠ P �矄 � 盐犨 矄 ᨨ �   � ᆠ�  ᨨ ├   ᨨᆠ├ 矄�ᨨ 泐 ⼄盐���盐鼀P졔f 㦨mg矄� q Þf㦨mg 矄� q - P ᨨ犨矄P� ᆠ矄矄f ᆠ矄矄 � 泐犨� 矄ᆠᨨP

҈黨

-

 

´





㡰  犨ᨨ ᨨᆠ矄 ᆠ� � ᨨ    � 矄ᆠ  mg   N

犨ᨨ ᆠᨨ鼀ᨨ  矄 ᨨ  鼀�  mgᆠᨨ矄 a ᆠ矄 N m㦨҈⏌ a mg矄� a�矄 ᆠ f N 泐  �ᆠ�ᨨ  ᨨᆠ \ N㦨mgᆠᨨ矄a mgᆠᨨ矄a a f㦨mg矄� a mg mg矄� a 盐f㦨ҘN㦨Ҙmgᆠᨨ矄a ҈ \ Ҙmgᆠᨨ矄a㦨mg矄� a Þ ᆠᨨa㦨 Þ ᆠᨨa㦨 Ҙ m 㦨� b㡰 �鼀�� � �ᆠ�ᨨ  ᨨᆠ fl㦨Ҙ矄N㦨�맔�㦨�N f � ᨨ�ᆠ⼄盐���盐鼀 �  ᨨ   ᨨᆠ├ � �ᆠ�ᨨ  ᨨᆠf㦨鼀�㦨黨N

鼀�㦨 ҈맔黨 㦨黨㦨␔

WWW.JEEBOOKS.IN

EBD_8341 PS-28



Physics

㡰 ᨨᆠ├�矄  矄 ᨨ⼄盐���盐鼀 �ᆠ�ᨨ  ᨨᆠ

N

和盐矄�盐� �g㦨҈鼀⏌矄㡰 Þ � + � m =  � - � m㡰 Þ � + � m =  -  m Þ � m = ҈�

f

f㦨鼀�矄� q㦨鼀�矄� 

=  ´ 黨 ´ ҈

mg矄� 

҈ = 黨 

mg

  =  = � ҈  I 和ᨨ = ҈ ҈ Þm=

mgᆠᨨ矄



�㡰 ᨨᆠ├ 鼀ᨨ� � 盐犨 矄�ᨨ 泐  

ᨨᆠ├

盐矄

鼀� 矄



f㦨mN F҈ q mgᆠᨨ矄q mg矄� q f mg

� F mg矄� q

�





ᨨ盐犨 鼀ᨨ� �ᨨ ᨨᆠ├盐矄 � � ᨨᆠF҈㦨mg矄� q졔 f \ F҈㦨mg矄� q졔mmgᆠᨨ矄q㦨mg 矄� q졔mᆠᨨ矄q㡰

 ᨨᆠ⼄盐�  ᨨ盐矄   � ᨨ鼀 矄� � � ᨨ犨  ᨨ ᨨᆠ├ 盐矄 鼀� 矄 矄�ᨨ 泐 F㦨mg矄� qm㦨mg 矄� qmᆠᨨ矄q㡰 ෌� F҈㦨F \ 矄� q졔mᆠᨨ矄q㦨 矄� q mᆠᨨ矄q㡰 \ ҈졔m㦨 ҈m㡰 ᲼Q 矄� q㦨ᆠᨨ矄q桌 \ m㦨 Þ m㦨� \ 㦨҈m㦨҈맔�㦨� �N㡰  �ᆠ�ᨨ  ᨨᆠ�矄矄ᨨ 矄�ᨨ鼀ᨨ 㦨鼀�  ᨨᆠ├ᨨ 鼀矄矄҈├�犨�  ᆠᆠ�ᨨ

ᨨ �鼀⏌矄  f

 ᨨ �ᆠ�ᨨ  ᨨᆠ f㦨m맔a㦨҈맔�㦨�N 鼀� 㡰 꾀ᆠᆠ�ᨨ  ᨨ ᨨᆠ├ 犨 �鼀ᨨ� � 盐   � ᆠ�    

a҈ = g 矄� q + mg ᆠᨨ矄 q Þ a҈ = g 矄� ° + mg ᆠᨨ矄°

g mg  +    矄� � v - u  = a s 㡰 =

 �㡰

Þ v -  = a҈ s㡰

Þ

v

v a҈

Q q 㦨ᨨ㡰

Q 盐㦨㡰

 ��㡰

꾀ᆠᆠ�ᨨ  犨 � 鼀ᨨ� � ᨨ犨    � ᆠ�     a = g 矄� q - mg ᆠᨨ矄 q  Þ a = g 矄� ° - mg ᆠᨨ矄 °

g m  g  ���㡰   矄� ���  v  - u  = as  ᨨ ᨨ犨 犨  鼀ᨨ�ᨨ

Þ a =



v æv ö Þ ç  ÷ =  a s 㡰 Þ s =  a è ø

ᔼ  ᆠ矄ᨨ P矄 矄 ᨨ犨 �  ��盐 泐� 鼀 � ᨨ矄��ᨨ    ᨨ� ᨨ  ᨨᆠ�泐 �矄 � ᆠ矄矄 盐 ᨨ N 矄� qᆠ 矄 鼀 盐O     ᆠ矄矄  ᆠ�犨泐矄鼀� 矄�  v和ᨨtPtQ 䰘 㡰

- a҈ s 㡰 = 

Þs=



矄  �ᆠ�ᨨ  ᨨᆠ ᨨᨨ矄矄   � 鼀ᨨ�ᨨ  ᨨ    矄盐 ᆠ ᨨ  ᆠᨨ ᆠ 꾀矄    盐矄 矄   矄盐 ᆠ �  ᆠ├犨  �ᆠ�ᨨ  矄ᨨ �ᆠ�ᨨ  ᨨᆠ    泐  矄盐 ᆠ ᨨ    矄ᨨ  �矄 �

  �ᆠ�ᨨ  ᨨ  �矄 鼀ᨨ�ᨨ  ᆠ㡰 �ᨨ盐矄 ᨨᆠ矄 ᆠ� � ᨨ    ᨨᆠ├  矄 矄 ᨨ犨  � 턼   ��盐 cos q ␔  q㦨�º矄� q㦨ᆠᨨ矄q q ҈

 ᨨᆠ├ 犨� 鼀�

矄� q q 矄�ᨨ 泐     �ᆠ�ᨨ  矄� q ᨨᆠ�矄 ᨨ ᆠᨨ矄 q ҈ ␔  q>�º矄� q>ᆠᨨ矄q

 ᨨ �ᆠ�ᨨ  ᨨᆠᆠ矄 q ᔼ쟼  ᨨ犨 矄 Q ␔  q� ᆠᨨ矄q>矄� q

 ᨨ  �ᆠ�ᨨ  ᨨᆠ ᆠ矄 ᨨ犨 矄 P 㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ   A   ᨨ� ᨨ  矄 矄 ᨨ Q q ᨨ  鼀矄矄矄�矄 矄鼀 A B v 꾀矄 ᨨ ᨨᆠ �矄 ᆠ� � �    Nᆠᨨ矄q N ᨨ� ᨨ  �ᆠ�ᨨ    q N矄� q ᨨᆠ�泐 ᨨ  Q 鼀� 矄   P 矄鼀�  ᨨ� ᨨ  O mg

 �㡰

쟼⼄盐� �⼄盐�ᨨ  ��㡰  �㡰

æg m ö g mg  v v = ç =  Þ a҈ = a Þ + ÷ ç    ÷ø a҈ a è

ᨨᆠ├犨� ᨨ矄�ᨨ犨�矄� m҈졔m㡰g 矄� q£mmg ᆠᨨ矄q

 q £

mm g ( m҈ + m ) g

mm Þ  q £ m҈ + m

f㦨mN

N q m҈ 졔m㡰g ᆠᨨ矄q

m҈ 졔m㡰矄� q

 ´  ҈ m҈졔 m㡰g Þ  q £ £ q ҈+  � Þ  q£�q £҈҈� �ᔼ   �q҈҈�   �ᆠ�ᨨ  ᨨᆠ�矄矄矄 

mN㦨mm� 㦨맔맔g㦨�  �矄⼄盐ᨨ m҈졔m㡰g矄� q ᨨᆠ├矄 犨� ᨨ 矄� ᨨ    � ᆠ�       �ᆠ�ᨨ  �矄 矄�ᆠ 꾀q>҈҈�  ᨨ �矄矄鼀ᨨ� �ᨨ  � ᆠ�      �ᆠ�ᨨ �矄├� �ᆠ ⼄盐ᨨmmgᆠᨨ矄 q  ᨨ鼀ᆠ�ᨨ N҈㦨mma矄� q N㦨mg 꾀泐� � 矄盐 ᨨ ᨨᆠ ma   矄ᨨ� � � F 㦨mar maᆠᨨ矄 q  f҈졔f㡰㦨mar maᆠᨨ矄 q ҘN҈ҘN㦨mar

WWW.JEEBOOKS.IN

PS-29

Laws of Motion maᆠᨨ矄 q Ҙma矄� q Ҙmg㦨mar Þ ar㦨aᆠᨨ矄 q Ҙa矄� q Ҙg

    - ´ � ´ - ´ ҈ = ҈ 鼀 ⏌ 矄  � � � � 꾀ᆠᆠ�ᨨ  ᨨ ᨨᆠ├ ᨨ犨      mN = f K mg 矄� q - m k mg ᆠᨨ矄 q a㦨 m

矄ᆠᨨ ��ᨨ 矄犨�矄�矄 � 犨  T҈�N矄泐T㦨҈   f҈㦨f㦨҈N

 ᨨ ᆠᨨ ��ᨨ  f҈ 㦨 f 犨� ᨨ 矄�矄 � 

盐矄 m҈   m ᨨ  ᆠ Ἐ 鼀�  矄�ᨨ 泐 ᔼ   矄ᆠᨨ  ᆠ矄犨   m҈  m ᨨ  鼀ᨨ f㦨 f㡰鼀 㦨҈�N \ f҈㦨f㦨N 和� ᆠ f҈   f҈㡰鼀   �矄 ᨨ � 鼀ᨨ�ᨨ  犨  m҈   M �.e.    鼀矄矄矄 鼀ᨨ 犨�  矄鼀 ᆠᆠ�ᨨ  矄泐 ἘaἘ ᨨ 泐 ��鼀矄 ⼄盐�ᨨ 矄ᨨ 鼀ᨨ�ᨨ 矄 ᨨᨨ犨矄

㦨 � ´

\

aA㦨g矄� q Ҙk,Agᆠᨨ矄 q



q

mg矄� q

mgᆠᨨ矄q

㦨�矄� � Ҙᆠᨨ矄�

N = mg ᆠᨨ矄 q

mg

æ ҈ ö æ ҈ ö = ҈ ç - 㡰 ҈㡰 ç =  è  ÷ø è  ÷ø 꾀 aB㦨g矄� q Ҙk,Bgᆠᨨ矄 q 㦨�矄� � m├�ᆠᨨ矄� æ ҈ ö æ ҈ ö = �  鼀⏌矄 = ҈ ç - 㡰 ҈㡰 ç ÷ è ø è  ÷ø aAB�矄�ᆠᆠ�ᨨ ᨨ A犨B 

aAB㦨aA aB

� �矄 ᆠ犨  A  BL ҈  L㦨 a AB t   㡰 L L = = ᨨ t㦨 a AB a A - aB   - � 

(

) (

)

Þt㦨ᨨt㦨s �矄 ᆠ鼀ᨨ 泐A 盐� �   �鼀�矄 ��  泐 ҈ ҈  SA㦨 a t 㦨 ´ �  ´  =   鼀  

҈

和�鼀�泐 ᨨB 㦨 䰘  鼀  ᆠᨨ  ᨨᆠ├矄犨�ᆠᨨ鼀� �  A 矄  �矄 ᆠ   鼀  ᨨ犨      㡰 ᨨ 泐 ��鼀ᨨ 鼀矄矄 M T T

T

m mg  �㡰 mg ᆠᨨ矄 q + m 矄� q �  �� �   ᨨ ⼄盐�ᨨ  犨 q  犨 � dF m mg = ᲼- 矄� q + m ᆠᨨ矄 q桌 =  d q ᆠᨨ矄 q + m 矄� q 㡰 



F

T

㡰  鼀 �鼀盐鼀 盐ᨨ  ᨨᆠ ᨨ  �ᆠ�ᨨ  犨  鼀҈  㝐 f҈㡰鼀 㦨 㡰 㡰 ҈㡰㦨N  �㡰

 鼀 �鼀盐鼀 盐 ᨨ  ᨨᆠ ᨨ  �ᆠ�ᨨ  犨  鼀   㝐 f㡰鼀 㦨 㡰 �㡰 ҈㡰㦨҈�N  ��㡰 ᨨᆠ矄ᨨ m҈ m�  ᨨ� ᨨ  �ᆠ�ᨨ 矄 ᨨᨨ犨矄





f

m

F㦨

\ q 㦨 ҈Ҙ

�矄�矄  � ᨨ鼀� �鼀盐鼀 ᨨᆠ

ᨨ �    鼀� �鼀盐鼀 ᨨᆠ 矄盐矄�盐� �  矄 盐矄 �

⼄盐�ᨨ  �㡰 Ҙ ҈ 矄� q 㦨 ᆠᨨ矄 q 㦨    Ҙ +҈ Ҙ +҈

N

T

T

M

F f҈㦨 f㦨҈� ᨨ鼀矄矄m ҈T㦨a  ���㡰 ᨨ鼀矄矄m T҈�㦨�a  �㡰 ᨨ 鼀矄矄 㝐F㦨�a  㡰 꾀 � �⼄ ���㡰 �㡰犨�   ᆠᆠ�ᨨ a㦨 鼀 ⏌ 矄  � �´ ᨨ鼀⼄ �㡰 ҈�㦨  Þ 㦨҈ �  ᨨ鼀⼄ 㡰 㦨 � ´ Þ 㦨 �  ᨨᆠ � ᨨ鼀ᨨ ᨨ 泐   � q  ᨨ   ᨨ� ᨨ  F矄� q

ᨨ 泐犨� 鼀ᨨ犨   F N Fᆠᨨ矄 q 㦨ҘN q ᨨ鼀 ��盐 ᨨ鼀ᆠ�ᨨ ҘN Fᆠᨨ矄q N㦨mgF矄� q ᆠᨨ矄q㦨Ҙ 鼀� 矄� q㡰 Þ

N҈ Mg

m



a

F㦨

Ҙ mg ҈ Ҙ + ҈

T

+ 

  ᨨ 泐 犨ᨨ ᨨ矄矄����矄 ᔴ矄ᔼ쟼� ᨨ m҈ m犨�鼀� 矄�ᨨ 泐 犨 �ᨨ盐 㡰 ᔴ矄ᔼᔼᨨ m҈ m犨�鼀ᨨ 犨�ᨨ盐 㡰 �矄ᆠ矄 �矄 ᨨ矄矄� 犨 

ᨨ T f҈㡰鼀 ᨨ TN T f㡰鼀 ᨨ T҈�N

m

+1



f҈㦨

a T

Þ F㦨



Öm

黨

m Ҙ + ҈

Ҙ mg Ҙ + ҈㡰 

Ҙ +҈

=

´m

q

1

Ҙ mg

Ҙ + ҈

Þ F㦨mg矄� q 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  鼀矄矄 M҈ 鼀ᨨ矄 ᨨ犨 犨 矄 犨�  盐 � ᨨ鼀 ᨨᆠ�泐�  ᆠᆠ�ᨨ  ᨨ   矄泐矄鼀 �矄 ᨨ 졠  盐� � ᨨᆠ ᨨ  矄泐矄鼀�矄 ᨨ

WWW.JEEBOOKS.IN

EBD_8341 PS-30

Physics

ᨨ⼄盐���盐鼀 㡰 M҈g㦨Mg矄� 䰘 졔mMgᆠᨨ矄䰘 졔mMg ᨨ M҈㦨M矄� 䰘 졔mMᆠᨨ矄䰘 졔mM

F

æ ö æ ö = 㡰 ç ÷ + �㡰 㡰 ç ÷ + �㡰 㡰 =  ├� è �ø è �ø 㡰 和� ᆠM�矄 鼀ᨨ� �犨� 盐 � ᨨ鼀ᨨᆠ�泐

㦨m҈mg㦨 �㡰맔맔黨㦨黨   T     矄�ᨨ  �    ᨨ  ᨨ�  P   a    ᆠᆠ�ᨨ  ᨨ 盐ᆠ  �    ᨨ F 㝐矄矄 盐 � � ᨨ  ᨨ�矄 m = L A P B F Ll l L ᨨ   AP錐 T㦨m L㡰a  �㡰 ᨨ 錐 FT㦨m⏌a  ��㡰 é T ù F - T = ml ê ᲼矄� �⼄ �㡰桌 ú ë m L - l 㡰 û Tl é l ù ÞT ê + l ú = F錐 L-l L l ë û é L ù æ L -lö Tê = F ÞT = Fç è L ÷ø ë L - l úû l ᨨ T = F é҈ - ù ê Lú ë û  꾀矄ᆠ盐矄 ᨨ ᨨ矄�  ᨨ犨

   矄  ᆠ  泐  矄 a 矄鼀 ᆠᆠ�ᨨ  鼀҈ 矄盐 ᨨ ᨨᆠ㡰 ᔴᨨ 矄�     ᨨ    a ᆠ盐矄 ᨨ � � ᆠ�  鼀҈ �

졔鼀҈ ᆠᨨ矄a㦨m҈g矄� a® �㡰

졔鼀�矄� b㦨mgᆠᨨ矄b® ��㡰 鼀 ᆠᨨ矄b 鼀 쟼⼄ �㡰쟼⼄ ��㡰 b 鼀 鼀҈ᆠᨨ矄a졔鼀ᆠᨨ矄b㡰f b 㦨 鼀҈矄� a졔鼀矄� b㡰� Þ

�

T

f  = m m A + mB 㡰 g

f҈ = m mA + mB + mC 㡰 g 꾀矄C�矄鼀ᨨ� �犨� ᆠᨨ 矄 矄 F㦨f҈졔f졔T �㡰  ᨨ鼀矄矄B�矄 mm A g = f m m A + mB 㡰 g = f 

B

T

꾀矄B�矄鼀ᨨ� �犨� ᆠᨨ 矄 矄 f졔 f㦨T  ��㡰 和盐ᆠ� �⼄ ��㡰 ᨨ鼀 �㡰 F f졔 f㡰㦨f҈졔f졔TT㦨f҈졔f Þ F 㦨f҈졔f졔f㦨Ҙ mA졔mB졔 mC㡰g졔 Ҙ mA졔mB㡰g졔ҘmAg F㦨Ҙ mA졔mB졔mC㡰g ෌� 鼀꾀㦨├�鼀㦨├�㝐㦨�├� m㦨�㡰 㦨�᲼맔졔맔졔�桌맔黨㦨䰘҈�N  ᆠ ᨨᆠ ᆠ矄矄泐ᨨ � 㦨 䰘҈�N

Topic-4 : Circular Motion & Banking of Road ҈

F -T =

鼀҈矄� a + m 矄� b㡰 f = g 鼀҈ ᆠᨨ矄 a + 鼀  ᆠᨨ矄 b㡰

C

mv  = mrw  r w㦨pn㦨p맔�㦨䰘p ⏌矄ᆠ  �盐矄r㦨҈�ᆠ鼀㦨҈�맔҈鼀 ᔴᨨ �ᆠ� ᨨ  �ᆠ�ᨨ Ҙ㦨䁸 m rw 㡰  mmg =  Qv㦨rw㡰 r Ҙmg㦨mrw

㡰 矄� � mmg =

 ö æ ҈� ´ ҈- ´ ç 䰘 ´ ÷ è rw 䰘ø = Þ m= g ҈

O

�矄ᆠ





 鼀҈�矄� a

鼀�矄�  b

鼀�

é m 矄� a + m 矄� b ù ᨨ鼀⼄ �㡰 = 鼀҈ g 矄� a㡰 - 鼀҈ᆠᨨ矄 a㡰 ê ҈ úg  ë m҈ ᆠᨨ矄 a + m ᆠᨨ矄 b û  é m҈ ᆠᨨ矄 a 矄� a + m҈m ᆠᨨ矄 b 矄� a - m҈ ù ê ú ᆠᨨ矄 a 矄� a - m҈m ᆠᨨ矄 a 矄� b ú ᨨ = g ê ê ú 鼀҈ᆠᨨ矄 a + 鼀  ᆠᨨ矄 b㡰 ê ú êë úû m m [ ᆠᨨ矄 b 矄� a - 矄� b ᆠᨨ矄 a ] g ᨨ T = ҈  鼀҈ᆠᨨ矄 a + 鼀  ᆠᨨ矄 b 㡰 ␔   ᨨᆠF�矄� ᨨ ᨨᆠ├C犨�鼀ᨨᨨ犨 矄    ᨨᆠ├ἘἘ犨�鼀ᨨᨨ犨 矄��  盐ᨨᆠ�ᨨ ᨨ Cᨨ B犨 �ᨨᆠ├A犨泐矄鼀� 矄矄 =

  ᨨ鼀矄矄C �矄

҈�ᆠ鼀

=

҈� ´ ҈- ´  =  ҈

㡰 ෌� q㦨� 㦨鼀�㦨҈鼀⏌矄 鼀   �㡰

矄� q = 

ᆠᨨ矄 q = 鼀�  ��㡰 ᨨ鼀⼄盐�ᨨ  �㡰 ��㡰犨 

 q =



q

 �

㦨� Qq㦨�  ᆠ 矄  ᨨ   盐盐鼀 �  �矄 ᆠ�ᆠ盐  

 = � =  ´ ҈ 㦨鼀⏌矄 ᆠ㡰 㡰  ᨨ� ᨨ  ᆠᨨ鼀ᨨ   ᨨ   矄�ᨨ  ᨨ� 矄  

ᆠ矄矄泐 ᆠ � ᨨᆠ \ 矄� q =



鼀 㦨鼀 w

q L

R R = mRw ᲼Q矄� q㦨 桌 L L

 T = = \w= � ´ � mL

=

Tᆠᨨ矄q T q

T矄� q R

mg

 ҈ =   ⏌矄  = � �

WWW.JEEBOOKS.IN

PS-31

Laws of Motion �

㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ    矄  犨�  犨 �ᆠ    ᨨᆠ├ 矄 ᆠ├�矄 矄鼀�  ᆠ├矄   ᨨᆠ├�矄矄ᨨ 矄鼀 �� 矄ᨨ ᨨ鼀犨ᨨ ᆠᨨ 矄�ᨨ

ᨨ  �泐矄 ᨨ  ᨨᆠ├ �� 矄ᨨ� 犨�矄鼀 �  ᨨ盐ᆠ矄矄    ᨨᆠ�泐   �� 矄 ᨨ�   v



bᆠ㡰꾀ᨨ � �盐矄  ᨨᆠ㦨 ᆠ � ᨨᆠ

æ Mv  ö ç ÷ ç l ÷ è ø 꾀  ᨨ �  �   ᨨᆠ 㦨鼀矄 鼀ᨨ�ᨨ ᨨ  盐盐鼀�矄   ᨨ ᆠ�ᆠ盐 鼀ᨨ�ᨨ 



\ 졔鼀�㡰ᨨ� 矄 ᆠ � ᨨᆠ

mv  犨  l l�矄  � ᨨ   盐盐鼀 v�矄 ᨨᆠ�泐ᨨ   ᨨ ᨨ⼄盐���盐鼀ᨨ  ᨨTmgᆠᨨ矄  =

\ mg ᆠᨨ矄 q - N =

mv R

黨

q Mg Mgᆠᨨ矄 q

g

gᆠᨨ矄q

꾀 mat㦨mg 矄� q Þat㦨g矄� q  �盐矄ᨨ ᆠ�ᆠ㦨 ᔼ DOCPOC㦨CP㦨R \ ÐCOP㦨ÐCPO㦨  Þ ÐOCP㦨 \ DOCP�矄 ⼄盐�� � Þ OP㦨R

C

R R 

ᨨ

mgᆠᨨ矄

A h

N v q

mg矄� q

mg

P mg

O

R R = =x  

 ᨨᆠ矄 ᆠ� � 矄 ᨨ犨  �    ��盐 �㡰 ᨨ鼀 ᨨ  � � ᨨᆠ �     � � �ᆠ�ᨨ

㦨Fᆠᨨ矄 졔mgᆠᨨ矄 㦨᲼kx졔mg桌ᆠᨨ矄 \

쟼  矄�ᨨ ᨨ 矄� �㦨 R -

N B

N = mg ᆠᨨ矄 q - mg + mg ᆠᨨ矄 q N = mg ᆠᨨ矄 q - mg N = mg ( ᆠᨨ矄 q -  )  ᔴ泐犨   ᆠᨨ矄 q > N�矄ᨨ矄��ᆠ矄 �泐ᨨ盐犨 矄    �  ᆠᨨ矄 q < Nᆠ矄 �泐� 犨 矄 

N F㦨kx

M

mg

mv  Þ N = mg ᆠᨨ矄 q  �㡰 R mg ᆠᨨ矄q 꾀  泐  �泐ᆠᨨ 矄�ᨨ  q ҈  mv = mg [ R - R ᆠᨨ矄 q ]  v =  g (҈ - ᆠᨨ矄 q ) \ R v 盐� � �矄盐ᨨ  � ⼄  �㡰 R N = mg ᆠᨨ矄 q - m [  g -  g ᆠᨨ矄 q] Þ Þ Þ

Mg矄� q

q g矄� q

T

꾀矄  �矄鼀ᨨ� �꾀ᨨ��  ᆠ�ᆠ盐 



q

l

 ᆠᆠ泐T>mgᆠᨨ矄  㡰

T

 

mv  T㦨mgᆠᨨ矄 졔 l

mv   �矄 犨泐矄  ᨨ矄�� ⼄盐 �泐 l 䰘

Mv TMg ᆠᨨ矄 q = l

鼀 ᨨ ᨨ 泐

mv  N + mg = R mv  N= - mg ᨨ R    �盐矄ᨨ ᆠ盐盐㡰�  �矄ᆠ矄�矄鼀� �鼀盐鼀  ᆠ ᨨ鼀ᆠ�ᨨ 犨�鼀 �鼀盐鼀�  �矄ᆠ矄 矄  �盐鼀�盐 ᨨ   盐盐鼀�矄 ��  犨   �矄  �盐 �矄ᆠ鼀  �矄    

\

l

v

졔鼀�



q

F矄� ᨨ

ᨨ

F 졠

ᨨ

鼀�矄� ᨨ ᨨ

Fᆠᨨ矄ᨨ 鼀� 鼀�ᆠᨨ矄ᨨ

 � �

� mg �   \Ft㦨mat Þ at㦨 �   꾀矄ᨨ犨    � � �矄 盐矄 矄 N졔F矄�  㦨mg矄�  mg ö ҈ mg æ Þ N㦨 mgF㡰矄�  㦨 ç mg ÷´ = è  ø   Ft

㦨

WWW.JEEBOOKS.IN

EBD_8341 PS-32

Physics

Work, Energy & Power

5

ᔼ �� � ᨨ  矄� 矄

Topic-1 : Work Done by Constant & Variable Force ҈

W =

㡰  ��

矄�盐�ᨨ  ᆠ   F 犨  � �ᆠ泐矄 B A 矄 ᨨ犨  �  ��盐  ␔ᨨ├ ᨨ  㦨 꾀 盐  F㜠x � E ҈ 㦨 꾀 ᨨ  ᆠ � ABCD 졔 꾀 ᨨ C F D  �盐鼀 BCFE ҈�鼀 鼀 ҈ W =  ´ ҈�㡰 + ҈ + 㡰 ´ ҈� =  + � 

䰘

ᆠ㡰 ᔼ AC㦨l  ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ BC㦨l AB 㦨l ᨨ盐� 犨ᨨ├ ᨨ 泐  m ᨨᆠ矄 �矄 ᨨ q W �ᆠ�ᨨ 졔Wmg㦨 A

和鼀ᨨᨨ

mg l 㡰矄� q - mmg ᆠᨨ矄 q l 㡰 = 

\k =  



r uur

ᆠ㡰 ␔ᨨ├ ᨨ  W = ò F × ds

(

)(

= - x�$ + yˆ × d ´ �$ + dyˆ 

)

黨

҈

҈ ҈ Þ W =  ò xdx + ò ydy = æç  + ö÷ + = ҈J è ø  ҈  

�



鼀� 鼀� Þ㦨 㡰    鼀� 㦨鼀 㦨   㦨 ᨨ鼀ᆠ�ᨨ

ᨨ犨犨ᨨ├ ᨨ 泐 ᨨ鼀ᆠ�ᨨ �ᨨ

r r æ 鼀� ö æ ҈ ö ᨨᆠ├� �鼀 ␔㦨和㦨 çè ÷ø çè �⏌   ÷ø   鼀�    ᨨ ␔ 㦨  矄 㡰 ᨨ鼀 ⼄盐矄�ᨨ   =  矄 =      ᨨ  矄 =  Þ 和 =   = 鼀´  鼀      ҈   ␔ᨨ├ ᨨ  = ´ = 鼀     ᆠ㡰 ␔ᨨ├ ᨨ  �  矄ᆠ � �   盐㜠  泐  �矄 ᆠ dx �矄 dW㦨F dx㦨 ax졔bx㡰dx



㡰  �盐矄ᨨ ᆠ�ᆠ盐 㦨

⼄盐�ᨨ ᨨ ᆠ�ᆠ�矄 졔泐㦨 ෌�  ᨨᆠ



l矄� q

Þ mmg ᆠᨨ矄 ql = mgl 矄� q  Þ m =  q = k  q



aL bL +  

é �ˆ r 泐ˆ ù = ⧤ ê  ⏌  +   ⏌  ú 㡰  㡰 ûú ëê  㡰

B

C

L

 ò axdx + ò bx dx =

é ù r �ˆ 泐ˆ + = ⧤ê ú   ⏌   + 泐  㡰 ⏌  ûú ëê + 泐 㡰

Þ W = ��  

L

矄  泐㡰

ˆ r ⧤ 泐 =  éë �ˆ + 泐ˆùû  㡰 �ˆ

 ᨨᆠ ᆠ矄  �泐ᨨ盐犨 矄 矄 矄 ᨨ犨  �    ��盐     �矄ᆠ鼀  �矄  � � ᨨ   ᆠ�ᆠ盐       � 犨    ᨨᆠ 犨 �ᆠ  ᆠ矄  �泐 ᨨ盐犨 矄   �矄ᆠ鼀  犨 �ᆠ  �矄  � � ᨨ   ᆠ�ᆠ盐 �矄黨 \ ␔ᨨ├ ᨨ ␔㦨 和ᆠᨨ矄q㦨 b㡰 ᔼ   ᆠᨨ 矄� �  犨ᨨ├ ᨨ  ᨨ矄 ᨨ  ᨨ      �.e.,   �     ���ᨨ  � �矄  ᆠᨨ 矄� �  \ W҈㦨W㦨W r r r ᆠ㡰 dW㦨 F  dS  F = - K y�ˆ + xˆ㡰  ��

r dS = dx �ˆ + dy ˆ + dz kˆ dW =  K y �ˆ + x ˆ 㡰  dx �ˆ + dy ˆ + dz kˆ㡰

㦨K ydx졔xdy㡰㦨K ᲼d xy㡰桌 \

a a

a a

ò  dW 㦨 K ò  d xy㡰 a a

҈

ᨨ W = K ᲼ xy 桌   ᨨ W㦨Ka  ᆠ ᨨ 犨ᨨ├ ᨨ  泐  ᨨᆠ ᨨ    �ᆠ W㦨Ka 㡰 犨ᨨ├ ᨨ � � �� � 鼀矄矄盐犨�⼄盐 ᨨ  ᆠ  � �  ᨨ �  �泐ᨨ   鼀矄矄 h = ⏌ 㝐g 㝐矄矄㦨 醨  ᔴ㦨ᔴ ᨨ 鼀矄矄

C

�.e. W 㦨 ᔴ  � �  ᨨ �  �泐 M L MgL ´g´ = 㦨mgh㦨   ҈ ҈҈ 㡰 ␔     矄泐矄鼀 �矄 矄  T  mg = ma  �㡰 Mg  T = Ma  ��㡰 ᨨ鼀⼄ �㡰 ��㡰   M - m㡰 g = g ⏌ a= M +m  T㦨mg⏌

T a

m 㦨├� T mg M a Mg

WWW.JEEBOOKS.IN

PS-33

Work, Energy & Power ᨨbᨨᆠ├鼀=├� u㦨a㦨g⏌ t㦨҈s㦨䁸 ҈  ҈ g s㦨ut졔 at 㦨졔 ´ ´ ҈ = g ⏌   m㦨䰘├�㡰    \ ␔ᨨ├ ᨨ  泐  矄� � ᨨ  m  ´  ´ ҈ ´҈ mg g ´ ´҈ = =  T sᆠᨨ矄 㦨    ´  ҈ 䰘�㡰 r ෌�  ᨨᆠ F 㦨 ay�ˆ + axˆ㡰  a㦨҈鼀҈ r r ␔├ ᨨ犨   ␔ = ×  = a泐 $� + a $ × $� + 泐 $ \ ␔㦨a泐 졔a 泐 Wᨨ├ ᨨ  ᨨ鼀꾀® 泐㦨矄泐㦨҈

(

҈

ò

)(

 ҈ ´  =  Þ = 鼀⏌矄  ᔼ �� ᆠᨨ鼀矄矄�ᨨ  ᨨ 矄� � ҈�맔҈ 㦨Þ  »  盐矄� � 犨ᨨ├  �泐 ᨨ鼀 ␔�졔␔矄㦨D⧤쟼



҈

ò

�



ᨨ鼀®ᔴ 㦨矄 㦨҈ �

\␔ =

ò

҈

�

a 泐 =

ò a 泐 = a (-�) = -a ҈

ᨨ鼀ᔴ® 泐㦨矄泐㦨� �

\␔ =

a

ò a ´ � = - 



҈

ᨨ鼀®E 㦨矄 㦨� 

\␔ =

a

ò a ´ � 泐 = - 

�

ᨨ鼀E®  泐㦨矄泐㦨 \␔� = ò a ´  ´ =  ᨨ鼀 ®꾀 㦨矄 㦨

ò

\␔ = a ´  =  \ ᨨ犨ᨨ├ ᨨ ␔㦨␔ 졔␔ 졔␔ 졔␔ 졔␔ 졔␔ ҈





a a a - ( -҈) = 㦨䰘� 㦨aa - =    







Topic-2 : Energy ҈

䰘

ᆠ㡰 ␔├ ᨨ犨 盐  㜠 � ��矄 犨ᨨ├ ᨨ  泐   ᨨ 泐

҈ ´  + 㡰 ´  - 㡰 +  ´  㦨�졔㦨�  矄� � 犨ᨨ├  �泐 ᨨ鼀 D ⧤쟼㦨犨ᨨ├ ᨨ  \D ⧤쟼㦨� nl l  l = ᆠ㡰 l҈ + l = l  l҈ = nl \ l҈ = n +҈ n +҈ ҈ 꾀矄k µ   l k҈ l ⏌ n + ҈㡰 ҈ \ = = k nl 㡰 ⏌ n + ҈㡰 n b㡰 ᨨᆠ�泐ᨨ ҈├�ᨨᆠ├盐矄 ᨨ�ᆠᨨ� 矄犨� ├�

\W=





ᨨᆠ├ = � =  鼀⏌矄

├�



҈ ҈  ´ ҈� ´ ҈  -  㡰 =  - ´  ´    矄ᨨ� �  » ᆠ鼀 㡰 ␔㦨盐 盐� æ mg L ö MgL  = -ç´ = è n n ÷ø n  ᆠ㡰 ␔├ ᨨ犨 盐  㜠 � ��矄 犨ᨨ├ ᨨ  泐   ᨨ 泐 ҈ \ W = ´  + 㡰 ´  - 㡰 +  ´   㦨�졔㦨� 矄� � 犨ᨨ├  �泐 ᨨ鼀 D ⧤쟼㦨犨ᨨ├ ᨨ  \D ⧤쟼㦨� 㡰 㝐 �鼀盐鼀矄 �矄鼀 ᨨ矄��ᨨ ᨨ⼄盐���盐鼀 꾀 ⼄盐���盐鼀 ᨨ矄��ᨨ

㦨├ Þ = ├ ᨨ鼀 犨ᨨ├㜠 �泐 ᨨ鼀 ␔ + ␔矄 = D⧤쟼 ҈  ҈  㡰 ├ = 鼀 -      ҈ æ ö ҈ æ ö ç ÷ - ├ ç ÷ = 鼀  Þ ҈ = ҈ 鼀  è ├ø  è ├ø   ⧤  ᨨ  鼀 = 鼀├ ⧤ ¶盐 ˆ =  ˆ ᆠ㡰 = ¶  和� ᆠ�ᆠ�矄鼀ᨨ� �� ᆠ�ᆠ盐 鼀  ⧤ ⧤ = = Þ 鼀  =     ҈ ⧤ \ ⧤쟼 = 鼀 =   

ᨨ �泐㦨쟼졔⧤쟼 ⧤ ⧤ ⧤ = -  +  = ᨨ  Q 쟼 = -  �� 㡰    㡰  Vf �矄   �  矄  ᨨ  ᨨ 泐 ᨨ鼀 ⼄盐矄�ᨨ 矄 V ҈ ҈ mV f = mV  = � m⏌ s Þ Vf =    dV æ dV ö  F = mç 㦨kV ÷ = -kV \ ҈㡰 dt è dt ø Þ  ´ +

)

\␔҈ = a泐 = a = a 

矄� � � ᆠ� ᨨ  ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 盐矄  ᨨ   盐矄  ᆠᨨ�矄�ᨨ  犨 �





ò

dV

҈ V



҈

= -҈ K ò dt 

WWW.JEEBOOKS.IN

EBD_8341 PS-34

黨

҈

Physics

҈ ҈ - = ҈ K ҈㡰 ᨨ K㦨҈kgm҈ � ҈ 㡰 ⧤쟼㡰Ἐ㦨�奠ᨨ ⧤쟼  ��  ҈ � ҈ 鼀 Ἐ = ´ 鼀  Þ  Ἐ =  ҈   ҈ ᔴᨨ �ᆠ�  ᨨ 矄�盐�ᨨ  =  ᨨ犨 ᨨ  �矄 ᆠ  泐 ᨨᆠ �矄 ҈ö æ æ ҈ +  ö ç ҈+  ÷  = ç ÷ = ç ÷ =  ç ҈ -  ÷ ҈ è ø çç ҈ - ÷÷ è ø dV ᆠ㡰 矄� � 㦨鼀㦨 m dt dV t = ҈ ᲼Q m㦨҈├��� 桌 dt

ar  ar  �  + = ar    ҈ b㡰 꾀泐� � 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ

m҈u҈ 졔 mu 㦨 m҈v҈ 졔 mv ҈u졔m 㡰㦨҈ 㡰졔m 㡰 ҈u㦨 m 㦨

҈ ҈ ҈u  = m 㡰   和ᨨ� � 犨 � u 㦨  

҈  ҈ æ xö ҈ kx = K ç ÷ + ҈㡰   èø    kx = 黨 Þ  ´ ҈ kx  = 黨 Þ    ҈  \ Kx = 0.6  (ᨨ � ��  �泐 ᨨ    矄� �) 

҈

ét  ù ҈ ò dV = ò t dt  V =  êë  úû =  鼀矄 ᲼Qt㦨҈矄ᆠ�� 桌   ᨨ鼀 犨ᨨ├㜠 �泐  ᨨ鼀 v

(

҈҈

ᨨ  �泐 㦨 ⧤쟼 졔 쟼

҈�

  盐 - ҈㡰 ᨨ  = 盐 - =



ᔼ       � � ᨨᆠ �  泐ᆠ   ├  

盐矄� � 犨ᨨ├   �泐 ᨨ鼀

)

҈ ҈   ␔㦨D⧤쟼㦨 m V - u 㦨 ´ ҈ ´ 黨 = �    㡰 ␔ᨨ├ ᨨ 泐 �ᆠ�ᨨ 턼 㦨Ҙ鼀�x

\

҈  㦨 ÞPQ㦨m  PQ ␔ᨨ├ ᨨ 泐 �ᆠ�ᨨ 턼㦨Ҙ鼀�맔ᔴᨨ矄 맔

҈ ҈ ҈ ҈ ( - ҈) 㦨 鼀盐 鼀㦨 鼀盐 鼀盐    

 ù é ҈  ҈ - ( - ҈) ú 㦨 鼀盐 ê  ê ú

 ë û ҈ æ  - ҈ ö = 鼀盐  ç ÷  è  ø   盐鼀ᨨ  ├矄⼄盐�  ᨨ矄ᨨ  盐

ᨨ �矄 ᆠ   泐  盐  ᨨ ᆠᨨ鼀� � ᨨ 矄㦨 矄� � 犨ᨨ├㜠 �泐 ᨨ鼀 �� 

 ´  㦨   Ҙ鼀�  和� ᆠ犨ᨨ├ ᨨ 泐 �ᆠ�ᨨ ᨨ 矄PQ QR⼄盐 Ҙ鼀�x㦨   盐鼀�

㦨Ҙ鼀�맔

Þ x㦨   @�m 矄� �犨ᨨ├ �泐 ᨨ鼀鼀�矄�  맔㦨   Ҙ鼀�졔Ҙ鼀�x

҈

Þ 㦨   Ҙ Þ Ҙ㦨0.29 ␔ 鼀� ´ ҈ ҈ ´ 黨 ´ ҈ ´ ҈ = = b㡰 㦨 � 盐 � 盐 � 盐 黨 ᔼ 盐㦨 㦨黨맔҈  黨 ´ ҈  㦨҈黨맔҈├� 盐矄 㦨  ´ ҈䰘 b㡰 꾀矄 犨 ├ ᨨ犨  㦨   r

U =

ò ar 



dr =

ar  

 �㡰

mv  꾀矄 = ar  r mv 㦨 mar ҈  ᨨ鼀 ⧤쟼㡰㦨 ar  ��㡰 

ᨨ  �泐 㦨 ᨨ �  �泐 졔 ├� �ᆠ  �泐 ᨨ犨 ᨨ鼀 ⼄  �㡰   ��㡰

盐㦨



ᔼ � �矄�  㦨

҈

㡰 盐 � ��ᨨᆠ�泐ᨨ  盐ᨨ 鼀矄矄 鼀 꾀  矄矄� �  ᨨ盐�    ├ ᨨ  犨�    �矄 ᨨᆠ�泐 ᆠ矄矄 ᨨ 

(  ) =

҈ 鼀盐  -  

 é҈  (  - ҈) ù ҈ = 鼀盐  \  =

ú ᨨ  ( ) =  ê  鼀盐

 û   - ҈ ë

҈

㡰 ෌�  ├ 꾀 =   ⏌ 鼀  ├  =   ⏌ 鼀  犨     ᆠᨨ鼀� �ᨨ  ᨨ  矄� �矄 �矄 ᆠᨨ鼀矄矄  泐 ᨨᆠ 和� �꾀�矄ᆠᨨ鼀矄矄 泐   ᨨᆠᨨ鼀矄矄�ᨨ

� 矄� �

 = 䰘� - 㡰 ᆠ鼀 =  ´ =  䰘� - 㡰 和ᨨ� �犨� 㦨�ᆠ鼀  = 䰘� - � = 䰘�ᆠ鼀 ҈ ├ 㡰 쟼꾀  꾀 꾀  ´ �㡰  = = =  ҈ 쟼  ├   㡰  ´ 䰘�㡰 

WWW.JEEBOOKS.IN

PS-35

Work, Energy & Power ҈䰘

ᆠ㡰 꾀盐 F  t � ��矄  � � 鼀ᨨ鼀 盐鼀 ᨨ    ᨨ 泐

Ux㦨x㦨 x㦨

F t㡰

꾀ᨨ DAOB㦨

҈ ´  ´  =  矄 A N 

\ \

OA CD  �s = 졠 C t s OB CB  CD D = Þ CD㦨  ҈� é҈ ù 꾀ᨨ Dᔴ = - ê ´ ҈� ´  ú = -҈� 矄 ë û

 � � 鼀ᨨ鼀 盐鼀㦨҈�㦨�矄

p  �㡰 = = �  m  ´  ҈ ᆠ㡰 矄 犨    ᨨᆠ├ B �矄 �矄ᆠ  ᨨ犨 矄 犨 ҈ ᨨ 泐矄� �S҈�矄 ᆠᨨ鼀矄矄   S �矄 �  �矄 盐 矄 矄  ᨨ  ᨨ S �矄   ҈

 ᨨ   �泐矄ᨨ  �   矄泐矄鼀 㦨 k҈ x   ␔     ᨨᆠ├ �矄 矄  � 犨� ᆠᨨ鼀 ᆠ├ ᨨ   ⼄盐���盐鼀 ᨨ矄��ᨨ  ��  鼀ᨨ鼀 盐鼀 ᨨ矄 ᨨᨨ ᨨ ⼄盐���盐鼀 ᨨ矄��ᨨ    鼀ᨨ ᨨ犨 矄 犨 꾀矄  �矄  矄   矄� � S҈ᆠᨨ鼀矄 ᨨ�矄 盐 �    S �矄 ᆠᨨ鼀矄矄   쟼 矄ᨨ  �    矄� � S҈ �矄 矄ᨨ 矄 쟼ᨨ 矄� �S犨   ᨨᆠ├Bᆠ 矄�矄  鼀ᨨ矄��ᨨ   ᆠᨨ鼀矄矄� � S 泐 y ᔼ �矄 ᆠ盐矄 ᨨ �ᆠ�ᨨ   泐犨  和ᨨ  �泐 �矄 ᆠᨨ 矄 ҈ ҈    ҈ ҈ \ k҈x㦨 ky Þ 맔 kx 㦨 맔ky     y ҈ Þ x㦨y\ = x  ҈黨 b㡰 ᨨ ᆠᨨ 矄� ᨨᆠ矄 DU㦨  W \

⧤� �ᆠ �泐ᨨ  ᨨᆠ├ =

x

x

DU㦨 - ò Fdx ᨨDU㦨 - ò k xdx 

Þ U x㡰U 㡰㦨 -

Q U 㡰㦨㡰

kx  -U x Þ x㦨  k ᔼ矄 矄 ᨨᨨ犨x �矄 矄泐鼀鼀�ᆠ b㡰  x    鼀 �鼀盐鼀   矄�ᨨ  ᨨ   矄� �  鼀ᆠ  �ᆠ  �泐 �矄 ᆠᨨ 矄  矄ᨨ ᆠ矄 �    ���ᨨ ᨨ � �泐ᨨ 矄� �鼀矄矄矄泐矄鼀 Mgx㡰 \







kx 

U x㡰㦨 -

æ҈ è

ö ø

㦨 ��  � 矄� � 矄�ᆠᨨ � �泐 ç kx  ÷

҈  Mg kx Þ x = k  du 㡰 ᨨ鼀F㦨 dx dU x㡰㦨Fdx

Mgx =

҈

x

Ux㦨 -ò - kx + ax 㡰dx \

 x



kx  ax  Ux㦨 - ò Fdx  =   

k a ␔ ᨨ � �泐 ᨨ犨�ᆠᨨ盐ᨨ 犨 �ᆠ ᨨ �矄 ᨨ���  꾀矄ᨨ犨  犨盐x 㦨�  ��  盐 ᆠ�ᨨ  dU 犨�F㦨盐F㦨 dx dU =  � 矄ᨨᨨ  � 矄 ᨨ盐 Þ 꾀x㦨錐 dx  ᨨ

矄 ᆠ ᆠ�矄�ᆠ矄  矄   泐 �  㡰  b㡰 ␔   矄� � �矄 ᆠ盐 � ᨨ �ᆠ矄       �  ᨨ 꾀 Ux㦨 �� ᨨx>

꾀矄ᨨ Þ

k 錐 a

L   ᨨ���  � ᨨ 矄� �L 矄� �ᆠᨨ 矄  �矄K �� 㡰 ᨨ矄� �K맔L㦨ᆠᨨ 矄   K Ἐ    矄� � ᆠᨨ矄   ᨨ ᨨ � �ᆠ ᨨ 矄� � L  \ K맔L㦨 맔K Ἐ Þ K Ἐ㦨 K    p  ᆠ㡰 ⧤쟼㦨 錐᲼⧤쟼㦨⧤� �ᆠ �泐錐㦨鼀ᨨ鼀 盐鼀桌 m p҈ p = ⧤쟼҈㦨⧤쟼 \ m҈ m ᨨ � �ᆠ ᨨ  矄� � 㦨

\  �㡰

p҈

pl m҈ ml ҈ ҈ = = = Þ   p m m   ␔ᨨ├ ᨨ 㦨ᔼ ᆠ矄� 쟼졔�� � ⧤쟼 F맔d㦨mgh졔�� � ⧤쟼 ҈맔�㦨҈맔҈맔졔�� � ⧤쟼 ෌� � ⧤쟼㦨�㦨҈

n㦨�

p

=

\ \ � 㡰 ᨨ矄矄� ⧤쟼ᨨ  ᨨᆠ├㦨�� � 쟼ᨨ  矄� � 졔 犨ᨨ├ ᨨ �� 矄 �ᆠ�ᨨ

҈  ҈   mmgx + kx  mv 㦨 kx + mmgx Þv㦨    m  ´ ҈ ´ ҈ ´ ҈ ´  +  ´  ´  v㦨 ҈   \v㦨 㦨 \㦨 ҈ ҈  ҈�㡰 ᨨ鼀犨ᨨ├  �泐 ᨨ鼀

W = F × s = DKE =

҈  mv 

 V  =  gh

\F ×s = F ´

 ҈ ҈� = ´ ´  ´ ҈ ´  ҈  ҈

\ F = ҈� 

WWW.JEEBOOKS.IN

EBD_8341 PS-36

䰘



Physics

҈㡰 ⧤� �ᆠ  �泐㦨 ᆠ  � �  ᨨ �  �泐ᨨ   �ᆠ ⧤쟼㦨鼀�D ෌� m㦨҈├� Dh㦨  ҈㦨҈㦨҈m \KE㦨҈맔҈맔҈㦨҈J  㡰 꾀ᨨ� Ӹ ᆠ � ᨨᆠᨨ�  泐 ᆠᨨ鼀ᨨ   ᨨ 犨�� 鼀�

\ 鼀� 矄� ° =

\  =

҈  ҈ 鼀 = 鼀� + 鼀  

鼀�矄� 

\ 㦨  �

 �㡰

\ ᨨ鼀⼄ �㡰

\

t





Þ



v

L

B L

u

A

盐� � 盐ᨨ v ᨨ鼀⼄ �㡰

r   D v  㦨  u - g l㡰  ᆠ 㡰 꾀矄 �ᆠ �矄 ᆠ  盐ᨨ  泐 ᨨᆠ ᨨ  ᆠᨨ 矄  鼀� �盐    �矄  �ᆠ盐 ᨨ   ᨨᆠ�泐 ᨨ    �ᆠ矄ᨨ��矄ᆠ矄ᨨ 盐 � ᨨ鼀ᆠ�ᆠ盐鼀ᨨ�ᨨ 

 ᨨᆠ�矄 ᆠᨨ 矄  �  鼀� �盐   �矄 矄 ᨨ犨   矄  �矄

ᨨᆠ  �� �   ᆠ├� �ᆠ �泐犨�鼀� ᆠᨨ 矄  v

mV  gt  =  

F

v

F F

v

v

 ᨨᆠ�泐   ᆠᆠ�ᨨ  ᆠ  �矄 ᆠᨨ � 盐ᨨ盐矄泐 盐 ᨨᆠ  � �    �ᆠ�ᨨ   꾀®⼄錐®⼄矄錐ᔴ®⼄矄錐® ᨨ꾀   dU  d é U  æ æ x ö ù -U  ê ç҈ - ç ÷ ú = = x - a㡰 x x + a㡰 㦨 dx dx ê  ç è a ø ú a è ë û 㦨  x㦨x㦨ax㦨a  u㦨  x㦨ax㦨a U

dV dé g ù g =m ê ´ t ú 㦨m = gm 㦨ᆠᨨ 矄  ᨨ犨 F㦨ma㦨 m dt dt ë m û m b㡰 ᨨ鼀 ��盐�� � ⼄盐矄�ᨨ  ᨨ � �泐ᨨ  ᨨ� 꾀㦨鼀� 꾀 ᨨ � �泐ᨨ  ᨨ� 㦨 ᨨ � �泐ᨨ  ᨨ� ᔴ㦨鼀� ᔴ

ᨨ �泐ᨨ� 꾀쟼꾀㦨⧤꾀졔鼀� 꾀

ᨨ �泐ᨨ� 쟼㦨⧤

ᨨ �泐ᨨ� ᔴ쟼ᔴ㦨⧤ᔴ졔鼀� ᔴ 꾀ᆠᆠᨨ � � ᨨ   犨 ᨨ  ᆠᨨ 矄�ᨨ  ᨨ   �泐 쟼꾀㦨쟼㦨쟼ᔴ  �㡰 쟼꾀㦨쟼Þ쟼ᔴ>⧤ᔴ  ��㡰 쟼꾀㦨쟼ᔴ ⧤꾀졔鼀� 꾀㦨⧤졔鼀� ᔴ ⧤ - ⧤꾀 ᨨ 꾀 - ᔴ = ᔴ  ���㡰 鼀�

U U0 



g 矄 g g  ´ t �µ 錐V = =  Þ 矄=  鼀 鼀  m 和ᨨ V �矄 ᨨᨨ�ᨨ  ᨨ �   �矄 ᆠ ᆠ

ᨨ  ᨨᨨ�ᨨ  ᨨ ἘἘ

\V =

 �㡰





� =  - �   ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ 꾀ᨨ�    ᨨ ᆠ�ᆠ盐  ᨨ� 矄矄鼀 ��  盐 矄矄   和ᨨ ᨨᆠ�泐鼀ᨨ   ᨨ�  泐 鼀 和ᨨ⼄盐� ᆠ � ᨨᆠ = �矄鼀 �鼀盐鼀ᨨ� 矄     d æ҈ dk ö ҈ b 㡰G 㦨gt  k = mV  \ ç mV ÷ 㦨gt dt  dt è ø  m dV dV ´ V 㦨gt \ mV 㦨gt Þ  dt dt V

҈  ҈ mv + mgL = mu  졔  

r r   㦨  v - u  = v + u

�  ��㡰 

m ò VdV = g ò tdt

ᨨ

Þ v㦨 u -  gL  �㡰 r ᔴ  � �  ᨨᆠ�泐  D v 

鼀 

ᨨ犨 泐    �泐 ᆠᨨ 矄�ᨨ  犨  ᨨᨨ鼀 ᨨ�   ᨨ� Ӹ 泐

黨

҈

Þ 꾀> ᔴ錐⧤ᔴ⧤꾀 ᨨ鼀⼄ �㡰 ��㡰  �㡰犨� 꾀> ᔴ \ ⧤>⧤ᔴ 㡰 ᨨ鼀 � ᆠ� ᨨ ᆠᨨ 矄�ᨨ  ᨨ   �泐 KE㡰B졔 PE㡰B㦨 KE㡰A졔 PE㡰A

a

졔a

x

x U

U

졔a

ᨨ Fx =

x

a

졔a

x

 dU æ xö = -U  ç ÷ dx èaø

 dU e- x ⏌ a = U x x - a 㡰 x + a 㡰 dx a U dU ᨨ Fx = = -  ᲼ x - a㡰 x + a㡰桌 dx  a 



ᨨᔴ Fx =

WWW.JEEBOOKS.IN

PS-37

Work, Energy & Power  b㡰

N mgᆠᨨ矄 q犨�ᨨ� ⼄盐� ᆠ � ᨨᆠ





mv R mv  N㦨mgᆠᨨ矄q졔 R

Nmgᆠᨨ矄q㦨

҈ ҈´ ҈㡰  + 㦨䰘�     � b㡰 ␔ᨨ├ ᨨ  �� 矄 矄�  �ᆠ�ᨨ  㦨 ᔼ �� 鼀ᆠ  �ᆠ 鼀  �泐  �  鼀ᆠ  �ᆠ   �泐 턼 ҈ 鼀�矄�  ҈�㦨mgh 鼀    鼀� ҈ 鼀�ᆠᨨ矄 Þ ҈�㦨mg R矄�   鼀  Q h㦨R矄�  㡰 ҈ ҈ Þ ҈�㦨҈맔҈맔맔  맔҈맔v   \ v㦨҈鼀⏌矄  ᆠ㡰 ᔼ    �矄 ᆠ矄 鼀ᆠ  �ᆠ  �泐�矄 ᆠᨨ鼀泐 ᆠᨨ   � ᨨ  ᆠ盐矄 ᨨ  �ᆠ�ᨨ  �.e. ᆠ矄 �

҈ 鼀ᆠ  �ᆠ �泐㦨 mv  ␔ � �矄 矄ᆠᨨ  ᆠ矄   ᨨ  鼀ᆠ  �ᆠ  �泐 �矄 ᆠᨨ   � ᨨ  盐 ᨨ �ᆠ�ᨨ  盐  ᨨ   ᨨ 鼀ᆠ  �ᆠ  �泐 �矄 �   �    ᨨ鼀 ᨨ  ᨨ � 㦨҈맔҈맔

 �泐 ᨨ    ᨨᆠ├ �.e. ᆠ矄 �  鼀ᆠ  �ᆠ  �泐

҈ mv mgh 

 ᨨ 矄鼀  ҈ �矄 ᆠᨨᆠ 和鼀   �矄 犨ᨨ �  ᆠᨨ �ᆠ�  ᨨ  �ᆠ�ᨨ  犨

 ᨨᆠ├  矄盐 ᆠ ᨨ矄 ᨨ  ᨨ   �ᨨ � ᆠ� �ᨨ  䰘 ᨨ� 鼀矄矄 � 犨犨�  矄 v 㦨

 ᨨᆠ�泐ᨨ 鼀矄矄m �矄� 矄 㦨vᆠᨨ矄q㦨



v � 盐 M犨�  �矄 ᆠᨨ ҈鼀犨 �m犨��矄盐泐

҈鼀 � ҈㡰鼀 ᨨ鼀  �泐 鼀 ᆠᨨ 矄  �ᨨ  졠 㝐 q ᆠ矄� 쟼 ᨨ M㦨� ᆠ矄 ҈鼀 h vᆠᨨ矄q �  쟼 ᨨ  m 졔 �鼀 v � ᆠ矄� ⧤쟼 q ᨨ  ᨨ    h' �҈㡰鼀 v 㦨v ᆠᨨ矄q ᨨᆠ├矄 鼀 ҈  ҈  Mgh㦨mgh'졔 mv + m  ᆠᨨ矄 q㡰   ҈  ᨨ 㡰 黨㡰 ҈㡰㦨 �㡰 黨㡰 � - ҈㡰 + ´  ´ v   æ v ö ҈ 졔 ´ � ´ ç ÷  è �ø 和ᨨ� �犨�v㦨黨鼀⏌矄

⧤쟼ᨨ ᨨᆠ├㦨犨ᨨ├�� 矄 �ᆠ�ᨨ 졔쟼ᨨ 矄� � ҈  ҈ mv = m k mg BD + x 㡰 + kx    ҈  ҈  mv 㦨Ҙkmg ҈졔x㡰졔 kx   ҈ ҈ 맔�맔㦨맔�맔黨 ҈졔x㡰졔 맔x   ҈졔x졔x㦨� \ x졔x҈҈㦨 ҈ = ҈ 졠 矄ᨨ� �犨�x㦨 ҈

 矄� � �矄 ᆠᨨ鼀矄矄  泐҈ 鼀 矄ᨨ� � ᨨᆠY㦨kx㦨맔҈㦨N �ᆠ�ᨨ  ᨨᆠY㦨Ҙsmg㦨맔�맔黨㦨҈䰘N 和� ᆠ �ᆠ�ᨨ  ᨨᆠ>矄ᨨ� � ᨨᆠ ᨨ 泐犨�矄ᨨ  �.e.   ᆠᨨ鼀矄矄� �   矄� � 泐x \  ᨨ �矄 ᆠ  㦨AB졔BD졔x㦨졔҈졔҈㦨鼀

A

B 鼀

D

C

҈鼀

x

Y

黨

    ᨨᆠ ᆠ� � v N ᨨ A B �矄 ᨨ和� ᆠ T   ᨨᆠ├矄 꾀    B 鼀ᨨ� � 犨�  ᆠᨨ 矄  C T f ᨨᆠ�泐 mBg      矄�ᨨ  ᨨ    T v 矄� � x A

 犨�  ᨨ �ᆠ�ᨨ

mg ᨨᆠ 犨  ᨨᆠ├ A   C Q f 㦨 ҘN    �矄 ᨨ ᨨ鼀 ᆠ�ᨨ  ᨨ  A ᆠ盐矄 A �矄 ᨨ 盐矄 � � C 矄ᨨ �ᆠ�ᨨ  ᨨᆠ 犨

ᨨᆠ├꾀 ᔴ f㦨m㦨 꾀泐� �F 㦨maᨨ A mAgT㦨mA맔 \ T㦨mAg  �㡰 꾀泐� �F 㦨maᨨ B Tf㦨mB맔 \ T㦨f㦨ҘN 㦨ҘmBg  ��㡰 ᨨ鼀 �㡰  ��㡰 A

mA  = = ҈ ├� m    ᨨᆠᆠ� �ᨨ  矄� ��矄   矄�ᨨ ⼄盐ᨨ 矄ᨨ� � ᨨᆠ ma g T ҈黨 \ T㦨kx Þ x㦨 \ x㦨 㦨 k k k 쟼 �泐矄ᨨ  �  矄� � ҈ ҈ ҈黨 ҈黨 ҈黨 ´ ҈黨 = 黨  U = kx  = ´ k ´ ´ 㦨   k k  ´ ҈黨 ҘmBg㦨mAg Þ mB㦨

WWW.JEEBOOKS.IN

EBD_8341 PS-38



Physics

⧤쟼C㦨ᨨ矄矄� 쟼犨ᨨ├ ᨨ 泐 �ᆠ�ᨨ

ᔼ ᨨ ᆠ矄矄 犨ᨨ├ ᨨ 泐 �ᆠ�ᨨ  㦨 mmgx



ᆠ =

A

҈  mvc = mg y - mmgx   = gy - mgx

ᨨ

q(

\ vc㦨  g y - mx 㡰 B ᨨ犨⧤쟼F㦨ᨨ矄矄� 쟼犨ᨨ├ ᨨ 泐 �ᆠ�ᨨ

҈  D mv F = mgy - mmgx   a( G M ҈  vF = gy - mgx Þ  \

C



�.e. vC㦨vF㦨  gy - mgx

E

F

N

҈

ᨨ  犨     �矄  ᨨ犨  盐   ���ᨨ  盐 ᨨ   �矄 ᆠ� � ᨨ     犨 �ᆠ  �矄 矄ᨨ 矄� ᨨ   ᆠ  � �  鼀ᨨ鼀 盐鼀



ᨨ 矄� � 矄� �ᆠᨨ 矄 㡰 k맔  � 㡰l 㦨 ᔴᨨ 矄  l ᔼ  � �矄 鼀  ᨨ   �  �.e.    矄� � ᆠᨨ 矄   ᆠᨨ鼀矄   �鼀矄 �.e ⧤ 矄� �⧤� �ᆠ �泐 ⧤쟼㡰 鼀ᨨ鼀 盐鼀�ᨨ 



⧤쟼㦨

҈ p  ᨨ⼄盐盐ᨨ p,⧤쟼µ 鼀矄矄 m

� 䰘



\ P = mv

dv v dt

dv Þ P dt = mv dv dt t

ᔼ �� � ᨨ  矄� 矄

黨



ò

�矄 ᆠ s = v dt = 





ᨨ

\

ᆠ㡰

w E ᨨ犨 P = = = ᆠᨨ 矄 t t

t

 P ҈⏌  t dt = m

ò 

Þ

V㦨krt

\

v = ᆠᨨ 矄 k 㡰 \ t

҈  mv  = ᆠᨨ 矄 t

v㦨kt҈⏌  

ᨨ ds = kt҈⏌  dt 泐� �� � 犨 �

 P t ⏌  × m ⏌

P ⏌  × t Þ 矄 µ ⏌ 黨m 和ᨨ�  㡰�矄 ᆠᨨᆠ b㡰 ᨨ ᨨᆠ ⼄盐�  ᨨ�  鼀 �鼀盐鼀 ᨨ  ᆠᆠ�泐 �� 矄 �ᆠ�ᨨ  ᨨᆠ㦨N Fᨨ =Mg졔 �ᆠ�ᨨ

㦨맔҈졔 㦨졔㦨N 矄� �ᨨ犨P㦨F맔v ×䰘㦨맔v Þv㦨҈鼀⏌矄»҈黨m/s  ᆠ矄 ᨨ  ᨨ 盐ᨨ  �矄ᆠᨨ矄ᨨ҈黨鼀矄҈

Þs=

d d æ dm ö ÷ = v r´ ᨨ盐鼀㡰 = vr ᨨ盐鼀㡰 dt dt è dt ø 㦨vr맔 Av㡰㦨Arv ᨨ犨㦨 ᨨᆠ맔ᨨᆠ�泐㦨Arv맔v㦨Arv  ᆠᨨ犨 Pµv b㡰 ᆠ � ᆠᆠ�ᨨ ac㦨 krt ᆠ㡰 F㦨 v ç

ᨨ鼀 犨ᨨ├㜠 �泐 ᨨ鼀 ᨨ 犨ᨨ├ ᨨ  㦨 ᆠ  � �

├� �ᆠ  �泐

æ P ö ҈⏌  ҈  ÷÷ t  = mv  Þ v = çç  è m ø t

\和 ᨨ ᆠ犨 �鼀ᨨ� � ᨨ犨 �㦨҈�鼀⏌矄 㡰  b㡰

v

ò P dt = m ò v dv

q ᨨ矄 ҈ 犨ᆠ  q = ҈

犨 æ 犨 犨 ö = ç - ÷  è ҈  ø v Þ v = ҈� 鼀⏌矄 

v = k  rt  r dv 㦨kr at㦨 dt ᨨ犨 P㦨Ftv㦨matv \ ᨨ犨㦨mkrt

b㡰 ␔ ├ ᨨ犨   ᨨ犨P = Fv 盐 F = mav = m

 㦨    㦨   ᆠ 㦨 㦨  ᨨ犨㦨鼀㦨鼀  㦨㝐   ᆠ㡰 ␔ � 鼀ᨨ� � ᨨ犨 � ᨨ犨

 =   = 

Topic-3 : Power ҈

 =   

wö æ P = ç w 矄� q + ÷҈  è ø 犨 æ犨 犨ö  = ç + ÷҈ =  è ҈  ø

b(

vF㦨  g y - mx 㡰

b㡰 ᔴ � ᆠᆠ�ᨨ  ᆠ 㦨   

Þ s㦨 ҈

kt  ⏌  + C  Þ sµt⏌ 

�.e.�矄 ᆠ鼀ᨨ Sµt⏌ b㡰 ᔼ 鼀ᆠ � �矄盐�ᆠ 犨� ᨨ� �ᆠ�ᨨ �矄 盐ᆠ  졠盐盐 犨ᨨ├ 㝐ᆠ  �ᆠ  �ᆠ� ᆠ泐㦨 ᔼ 盐  �泐 盐 ᨨ 矄矄 �ᆠ�ᨨ  ᨨ盐盐 犨ᨨ├ 犨� � ᆠ矄 盐矄   鼀ᆠ  �ᆠ  �ᆠ� ᆠ泐� ᆠ矄矄 㝐ᆠ  �ᆠ   � 㝐꾀 㦨

҈҈

ds = kt҈⏌  dt

ᨨ  ᨨ

�㡰 矄� � 犨ᨨ├  �泐 ᨨ鼀 D ⧤쟼 㦨 ␔ 㦨  맔  ҈ 鼀 =  ´   \ =

 = 鼀

 ´ � ´ � = �鼀矄 -҈ 

WWW.JEEBOOKS.IN

PS-39

Work, Energy & Power ҈

  � ᨨᆠ�泐vἘ盐矄� �鼀ᨨ鼀 盐鼀ᆠᨨ 矄�ᨨ

҈㡰෌� 㝐矄矄ᨨ  ᨨ 泐m㦨├� ᨨ犨 � 泐 �� P㦨҈⏌矄

�鼀t㦨黨矄ᆠᨨ 矄 ᨨ犨P㦨Fv

᲼Q F = ma桌 dv ö æ çèQ a = ÷ø dt

Þ P = mav Þm

v ҈ ҈ ᨨ犨� �� �泐 E� = mv    v ҈ ҈ mv  �  �泐 E f = ´ ҈m ´ æç ö÷ =   ҈ è ҈ ø mv = ҈ mv Ἐ Þ v Ἐ =

dv v=P dt

҈  ҈ v mv - m   ҈ ҈ é ҈ù ҈  é҈� ù Þ mv ê҈ - ú Þ mv ê ú   ë ҈ û ë҈ û

쟼 �泐ᨨ矄矄 E� - E f =

P Þ v dv = dt m ᔼ �� � ᨨ  矄� 矄 犨 � v

Þ ò v dv = 

Þ

dx = dt x

Þ ò dx = 

t

P dt m ò

Þ

v  Pt æ  Pt ö = Þv= ç è m ÷ø m 

҈⏌ 

 ᨨ  �泐ᨨ矄矄 �矄 P奠 ᨨ   ᨨ���   �泐 쟼 �泐ᨨ矄矄 ´ ҈ 졠���  �泐 ҈  é҈� ù mv ê ú  ë҈ û ´ ҈ = 黨䰘�奠 =  ҈  mv  \ 奠P =

dx ö æ çèQ v = ÷ dt ø

P ҈⏌  t m t

 P ҈⏌  t dt m ò

 P t ⏌   P  ⏌  = ´ t \ �矄 ᆠ x = m ⏌  m   ´ ҈  ⏌   Þx= ´ ´ 黨 = ´ 䰘 = ҈   



Topic-4 : Collisions ҈

㡰  ᨨ ᆠᨨ�矄�ᨨ  ᨨᆠ�泐ᨨ �ᆠA u҈ = �ˆ + ˆ 㡰 鼀⏌矄 ᨨᆠ�泐ᨨ �ᆠBu㦨 꾀  ᆠᨨ�矄�ᨨ  ᨨᆠ�泐ᨨ �ᆠA v҈ = �ˆ +  ˆ㡰 ᨨᆠ�泐ᨨ �ᆠBv㦨 矄� � � ᆠ� ᨨ ᆠᨨ 矄�ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀

r r r r m҈u҈ + m u = m҈v҈ + m v r Þ m �ˆ + ˆ 㡰 + m ´  = m �ˆ +  ˆ 㡰 + m ´ v r Þ  �ˆ +  ˆ = �ˆ +   ˆ + v r r Þ v =  - ҈㡰�ˆ -  - ҈㡰 ˆ Þ v҈ = �ˆ +  ˆ r r ᨨ �犨  v҈   v  r r v ×v   - ҈㡰 ҈ - 㡰 ҈ -  ᆠᨨ矄 q = ҈r r  = = v҈v  ´    - ҈㡰   Þ q = ҈�° r r 꾀 �犨  v҈   v �矄҈�



 ᆠ盐ᨨ P�矄ᆠᨨ矄ᨨ黨 b㡰 ෌�  㝐矄矄ᨨ ᨨᆠ├m҈㦨҈黨├� 㝐矄矄ᨨ 盐m㦨҈├� ᨨᆠ�泐ᨨ 盐v㦨鼀⏌矄  v    ᨨᆠ�泐 ᨨ    ᆠᨨ鼀�   矄泐矄鼀 ᔼ �矄 

� 矄�ᆠ ᆠᨨ�矄�ᨨ  矄� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀

m҈ ´  + m ´ v = m҈ + m 㡰v Þ ҈ ´  = ҈ + ҈黨㡰 ´ v Þ v = ҈ 鼀⏌矄 矄� � 犨ᨨ├  �泐 ᨨ鼀 ␔ᨨ├ ᨨ  㦨ᔴ  � �  ⧤� �ᆠ �泐  K    ⧤� �ᆠ �泐ᨨ ᆠᨨ鼀�   矄泐矄鼀 鼀҈졔鼀㡰� ҈ = ⧤ -  鼀҈졔鼀㡰  ҈ Þ  ´ g ´҈ = K - ´  ´ ҈ Þ K = ҈   ᆠ㡰 ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 ur mu�ˆ +  = mvˆ + mv Ἐ ur u v v Ἐ = �ˆ - ˆ  

b㡰 꾀ᆠᆠᨨ � � ᨨ  ⼄盐矄�ᨨ   ᆠᨨ�矄�ᨨ 矄   ᆠ泐 � 矄�ᆠ矄ᨨ   � ᆠᨨ�矄�ᨨ ᨨᆠ├矄鼀ᨨ� � ᨨ�  m

ᨨ鼀 ├� �ᆠ  �泐 ᆠᨨ 矄�ᨨ  æ æ u ö æ v ö ö ҈ ҈ ҈ mu  = mv  + m㡰 ç ç ÷ + ç ÷ ÷ çè  ø è  ø ÷    è ø   ᨨ mu = mv +

\v = m

m v'

 ᨨ ᆠᨨ�矄�ᨨ

v =  - ҈㡰$� -  - ҈㡰 $

m

m

x

 �

v

m

m u

v҈ = $� +  $



v

y

m

꾀  ᆠᨨ�矄�ᨨ

mu  mv  +  

u 

m

WWW.JEEBOOKS.IN

EBD_8341 PS-40

�

Physics

b㡰

盐⏌

黨



ᆠ㡰

├� ҈鼀







盐⏌

҈鼀⏌矄





├�

x㜠 �ᆠ�ᨨ

mu u mu + = mvἘx Þ VxἘ =   mu u Ἐ = mv y Þ v Ἐy = 泐㜠 �ᆠ�ᨨ   +    ù é ҈ ҈ æ uö æ uö K E� = m u  + m ê ç ÷ + ç ÷ ú è ø è ø ú   êë  û

�鼀├  ᨨ   �ᆠ矄 ᨨ ᆠᨨ� 

҈ = =҈矄ᆠ  ҈ 和  ᨨ  犨ᨨᨨ  盐矄  ᨨ ᆠᨨ�矄�ᨨ  㦨 � 㦨 ҈ 鼀⏌矄  矄  ᨨ 盐 盐矄  ᨨ ᆠᨨ�矄�ᨨ  㦨  � 㦨҈҈㦨黨鼀⏌矄 ҈ 和㦨҈맔҈ 맔҈맔҈㦨黨�鼀  ᨨ犨 盐矄� � ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 盐矄  ᨨ       ᆠᨨ�矄�ᨨ

 㡰 ҈㡰졔 㡰 黨㡰㦨 �㡰v Þ҈�㦨�v \v = 鼀⏌矄 㝐  ��  ᆠ   泐ᨨ 泐 㦨

҈  mu  mu  mu + =      ҈ ҈ K 쟼  f = ( m) vxἘ + ( m) v Ἐy   éæ u ö  æ u ö  ù � ҈   =  m êçè  ÷ø + çè  ÷ø ú =  mu êë úû \ᨨ矄矄� KE㦨KEfKE� =

( )

( )

 㦨 =

 ᨨ ├� ҈鼀⏌矄

 æ  � ö mu = mu  ç - ÷ = è  ø 





㡰 꾀泐ᆠᨨ ᆠ�ᨨ ᨨ � 鼀ᨨ鼀 盐鼀�  Ӹ �ᆠ�ᨨ  ᨨ   矄泐矄鼀  

㝐 ҈ᆠᨨ矄 㡰졔㝐 �ᆠᨨ矄� 㡰㦨㝐 ҈ᆠᨨ矄 㡰 졔 㝐 ᆠᨨ矄� 㡰

�  +�  =

 ҈ +



├�

҈

 ҈㡰



꾀矄ᨨ 㝐 �矄� � 㡰㝐 ҈矄�  㡰㦨㝐҈矄�  㝐矄� �

�  - � = ҈ -



 㡰  和ᨨ� � ⼄盐�ᨨ  ҈㡰   㡰  + ҈ ҈ = �  + ҈  - � Þ ҈ = �鼀⏌矄

(

)

㦨鼀⏌矄 䰘

b㡰 m҈v҈졔mv㦨m҈v졔mv҈ ᨨ



m҈v҈졔 �m҈㡰v㦨m҈�v҈졔 �m҈㡰v

졠 矄ᨨ� �v҈㦨vv 㡰 矄� � ᆠᨨ 矄�ᨨ  ᨨ 鼀ᨨ鼀 盐鼀 mv㦨鼀鼀҈

҈  ҈ 鼀҈ =  ´ 鼀   Þ ҈ = 

ᆠᨨ�矄�ᨨ  �矄 矄�ᆠ 和ᨨ

a

҈҈





\ 㝐㦨鼀

Þ 鼀  = 鼀㝐

黨鼀⏌矄

�├�

\�� ᨨᨨ犨㦨鼀 ᆠ㡰 ⧤� �ᆠ �泐ᨨ ᨨᆠ├꾀 ҈ ├҈ = 鼀   \ ᨨ鼀� ᆠ� ᨨ  �  鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ

鼀 鼀 = ( 鼀 + 㝐 )  Þ  = 鼀 + 㝐 � 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  ᨨ      � �� ├� �ᆠ  �泐  �矄 ᨨ矄 �  犨 ᨨ ᨨᆠ矄矄 ҈ 鼀 ├�  = \ =  Þ  ├ ҈ æ 鼀 ö ( 鼀 + 㝐 ) çè 鼀 + 㝐 ÷ø  鼀 + 㝐 㝐 Þ =\ = 鼀 鼀 꾀 ᔴᨨ�矄�ᨨ

b㡰  ᨨᔴᨨ�矄�ᨨ



꾀 ᆠᨨ�矄�ᨨ

a

꾀  



 㝐



҈ ҈ 㝐 = ´ 鼀 ᲼\ 㝐㦨鼀矄矄ᨨ  盐ᆠ盐矄桌   鼀 Þ  = ´   鼀 = 鼀㝐 ´   鼀 ´  㝐

Þ҈ 鼀 =  鼀㝐

 ´  = � 鼀  ´ ҈



Þ

҈ 鼀

 鼀

和�ᨨ 泐

҈  ҈  æ҈ ö 鼀҈ + 鼀 = ç 鼀 ÷   è ø  Þ ҈ +  =   �㡰  ᨨ鼀 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ

鼀㦨鼀 ҈졔㡰  ��㡰 和⼄盐� � ᨨ  矄� 矄 ҈졔㡰㦨 Þ҈졔졔҈㦨

WWW.JEEBOOKS.IN

PS-41

Work, Energy & Power

 ҈ = -   ҈ -   㡰  =  ҈ +   - ҈ =

⧤쟼ᨨ矄�矄盐矄 ᨨ盐鼀 ᨨ鼀҈矄ᨨ�ᨨ ᨨ� D⧤쟼㦨҈ 㝐� �鼀盐鼀⧤쟼ᨨ  盐ᨨ  ᨨ� 矄�ᆠᆠᨨ�矄�ᨨ

҈ 鼀  㦨   ҈ 㦨   

    +   

和ᨨ� � 犨 � � ᨨᆠ�泐犨    犨ᨨ�ᆠ矄

҈ -  = ҈

Ӹ  㦨鼀 



㡰 ᔴ  �� 鼀ᨨ鼀 盐鼀

^  ˆ  ˆ  ˆ  ˆ + + �� D =      ^   ˆ   = ᔼ 鼀ᨨᆠ盐 D = ^ �  �  �  ^�  ˆ   ^   Þ ᔼ犨 =    矄矄盐  

Q = ᨨᨨ �ᆠ矄㡰 㦨 = 꾀 꾀  ´  ´ ҈ -䰘 ´ ҈ ´҈ = 㦨�맔҈⏌鼀  ´ ҈- ҈ 㡰 ᨨ ᆠᨨ�矄�ᨨ  ᨨ  盐ᨨ  犨�  盐�盐鼀  ҈  鼀 鼀 鼀 鼀 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ 鼀ᨨ鼀 盐鼀  鼀졔㦨鼀҈졔鼀  �㡰 ҈㦨  ��㡰 Q ᔴᨨ�矄�ᨨ �矄矄�ᆠ㦨҈  ᨨ鼀⼄  �㡰 ⼄  ��㡰 ҈ = 

҈�

㡰

鼀

ᔼ �� 鼀ᨨ鼀 盐鼀 ᨨ  矄泐矄鼀

^�

�㦨 ᲼鼀 㡰  ´ 鼀 㡰  桌 㦨 鼀 ´  � 鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀㦨鼀 泐   犨 ᨨ  ᆠᨨ 矄�ᨨ  ᨨ  鼀ᨨ鼀 盐鼀

 鼀v = 鼀  Þ

҈

 v = ᆠᨨ鼀�  

ᨨ矄矄 �   �泐 ҈ ҈ ҈  D쟼 = 鼀҈҈ + 鼀 - 鼀҈ + 鼀 㡰ᆠᨨ鼀�      � D쟼 = 鼀 - 鼀  = 鼀  㦨����奠   ᆠ �ᨨ矄矄�  �泐 盐� � ᆠᨨ�矄�ᨨ  ; �奠 㡰 ᨨ鼀 犨ᨨ ᆠᨨ 矄�ᨨ ᨨ 鼀ᨨ鼀 盐鼀犨├ ᨨ犨   鼀҈盐҈졔鼀盐졔㦨鼀҈҈졔鼀졔 ෌� 鼀҈㦨鼀鼀㦨鼀 鼀㦨鼀  盐҈㦨盐盐㦨盐 盐㦨盐

Ӹ 鼀盐



鼀҈

鼀҈ 졔 鼀  㡰

矄�   鼀盐



   �

 �ᆠᨨ矄 㡰矄�  鼀盐

ˆ 졔鼀맔盐 -ˆ� ᆠᨨ矄 ° - ˆ矄� °㡰 鼀맔盐 �㡰 ® 졔鼀맔盐 -ˆ� ᆠᨨ矄 ° + ˆ矄� °㡰 㦨 鼀졔鼀졔鼀㡰 

҈ ҈ æ ҈҈ ö 鼀  - 鼀 ç  ÷    è ҈ ø = »  ᆠ = ҈  ҈黨 鼀 

�ˆ 

® æ  ˆö æ  ö �ˆ  ÷ - 鼀盐 + 鼀盐 ç ˆ ÷ = 鼀  ÷ ç ÷  è  ø è  ø

Þ 鼀盐�ˆ - 鼀盐 - 鼀盐 ç ç

®

  ˆ 鼀盐�ˆ - 鼀盐�ˆ 鼀盐 = 鼀    ® ҈  ˆ 鼀盐 = 鼀  Þ - 鼀盐�ˆ   ® 盐 ˆ - � - ˆ Þ  = ҈ ҈䰘 b㡰 꾀矄

�矄 �矄 ᨨ 矄ᨨ� ��ᨨᆠ�泐u㦨  ҈  ҈ ҈   K.E. 㦨 mv 㦨 m [ u + at ] 㦨 m [  + gt ]    ҈  \ K E = mgt \ K E µ t   �㡰  Þ



҈  㦨 ҈ 졔 ҈㡰 

®  㡰  ᨨ  㡰 㡰 ® 꾀    ҈ ҈  æö  ҈ 鼀 鼀㡰 ᨨ矄矄� ⧤쟼㦨 ç ÷ = 鼀     è ø 㦨



 ᨨᆠ�泐犨    泐矄�ᆠ├ 㦨 

  ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ 

҈҈  ҈

㡰 ᨨ� 矄�ᆠᆠᨨ�矄�ᨨ  Ἐ 㦨

�

v

ᨨ犨 ᨨ ᆠᨨ�矄�ᨨ  ᨨ  盐ᨨ  犨�  ᆠᨨ  盐ᆠ盐矄  ҈  鼀 鼀 ҈鼀 ҈鼀 꾀泐� � ᔴᨨ 矄�ᨨ  ᨨ  鼀ᨨ鼀 盐鼀 mv졔㦨mv1졔҈mv2  ���㡰 㦨҈  �㡰 ᨨ鼀⼄  ���㡰 ⼄  �㡰

҈

�

®

҈ ҈ 鼀  - 鼀҈    = = 黨  = ҈  黨 鼀 

҈ = -

鼀 v

(

)

WWW.JEEBOOKS.IN

EBD_8341 PS-42

Physics

�.e. �ᨨ  犨  k  t �矄 ᨨ�ᆠ �矄   ├� �ᆠ  �泐犨� � ᆠ矄 矄  ⼄ �㡰 꾀矄   矄 ᨨ盐ᆠ 矄   �ᨨ盐  � 矄矄  ᨨ鼀� �   ᨨ矄矄 �矄 ⧤쟼犨     ᨨ鼀�ᨨ �矄鼀 �鼀盐鼀⧤쟼㦨꾀矄  鼀ᨨ矄盐�ᨨ矄矄⧤쟼 �� ���ᨨ ᨨ �  �泐�   矄鼀�鼀�  矄ᆠ ᆠ�矄�ᆠ矄  矄 �盐矄 泐kt �  矄 ᨨ犨  �  㡰



ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  犨  ᆠᨨ�矄�ᨨ    �ᆠ矄 鼀ᨨ 犨�  ᆠᨨ 矄  矄  꾀 �矄 ᆠᨨ�矄�ᨨ  ᨨ  �ᆠ � � 矄  v 犨� ᨨ  맔 ҈  㦨   犨 � ᨨ  �ᆠ � � 矄  v 犨� ᨨ҈  ᆠ �矄ᆠᨨ�矄�ᨨ ├矄ᆠ꾀 �矄 ᆠᨨ�矄�ᨨ  泐犨� ᆠ  � �ᨨᆠ��矄矄 ᆠᨨ�矄�ᨨ

�矄矄�ᆠ  �ᆠ矄 ⼄盐鼀矄矄矄꾀�� 矄ᆠᨨ ᆠᨨ�矄�ᨨ ├矄ᆠᔴ

盐  矄�  a g 盐矄� �盐㦨� é u  矄�  a ù v҈ - u =  - g 㡰 ê  ú ëê  g ûú

҈ 㡰

Þ Þ



a 鼀

҈

盐

鼀盐ᨨᆠᨨ矄a



꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 �

Ӹ㜠 �ᆠ�ᨨ

鼀矄� q㦨鼀҈㦨鼀盐ᆠᨨ矄a  �㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 �

㜠 �ᆠ�ᨨ

鼀ᆠᨨ矄q㦨鼀盐 ᆠᨨ矄a  ��㡰 �� � � �㡰  ��㡰犨� p  q㦨҈\q㦨� 㦨  㡰 Fᨨr vert�cal mᨨt�ᨨn ᨨf bullet ᨨr ball 盐㦨 㦨�鼀㦨䁸�㦨҈鼀⏌矄  鼀㦨҈├�

�鼀



ᔴ  ᆠᨨ�矄�ᨨ

r

� 㦨�鼀⏌矄 ҈  ᆠ� ��ᨨᆠ�泐ᨨ  盐㦨�鼀⏌矄

r

r

r

Dp㦨F  Dt㦨 ( m҈v҈ Ἐ+ mv Ἐ) - ( m҈v҈ + m v ) 㦨 m҈졔m㡰g맔t  㡰  ᆠ 盐矄 ᆠᨨ�矄�ᨨ 犨�  Aᨨᆠ�泐ᨨ B m - m A 㡰u B m A u A  + m ´ 黨 vB = B + = = 鼀⏌矄 mB + mA m A + mB m + m \

m

m

m

A

B

C

 ᆠᨨ�矄�ᨨ  犨  B  C �矄 ᆠᨨ鼀泐� 矄�ᆠ \ mB vB㦨 mB졔mc㡰v

 ´ m = 鼀⏌矄 m + m  �㡰 盐 ᨨ 矄�ᆠ   ᨨ  ᆠᨨ�矄�ᨨ  ᨨ ⼄盐 鼀矄矄 m ᨨ ᨨᨨᆠ�泐  �� 矄ᨨ� ᨨ ᨨ� ᨨ矄� �l҈�矄 ᆠ⼄盐�  泐  ᨨ �  ᨨ 矄� � l l \ �l҈ = ��l  Þ ҈ =� l  ҈㡰 m v=

v

盐

҈ ҈ h = ut + gt  Þ � = ´ ҈ ´ t    Þ 㦨҈矄ᆠ ᨨhᨨ� ᨨ 鼀ᨨ�ᨨ ᨨ b 㦨Þ 㦨맔҈Þ㦨鼀⏌矄 ᨨhᨨ� ᨨ 鼀ᨨ�ᨨ ᨨ b盐 盐㦨盐맔Þ ҈㦨盐맔҈Þ盐㦨҈鼀⏌矄 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 盐� � ᆠᨨ�矄�ᨨ  鼀㦨鼀盐졔㝐 ҈㦨҈맔҈졔맔 \㦨

҈

v ᨨ犨矄矄 ᨨ犨 �  ��盐 犨ᨨᆠᨨ�矄�ᨨ 矄 泐犨���

ᆠ  ᨨ� 꾀 㡰 F 㦨 m҈졔m㡰g Dt㦨t Dp F 㦨 Dt

Þ

㝐㦨├�

鼀 ҈鼀

v

v

鼀

盐  矄�  a =  �

盐

҈

҈ 

v

҈矄ᆠᨨ�矄�ᨨ

q 鼀ᆠᨨ矄q



҈黨

v

v҈ = u ҈ - 矄�  a㡰 = u ᆠᨨ矄 a ҈㦨盐ᆠᨨ矄a 鼀矄� q



v

�� h㦨

q q

鼀 v⏌

v

m

�

㝐ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ  ᨨ � x �ᆠ�ᨨ  v ҈ mv ᆠᨨ矄 q =  m  Þ ᆠᨨ矄 q = ᨨ q = °    ᆠ �犨  � ��ᨨᆠ��矄ᨨ  犨ᨨᨨ �矄 = q + q = ° + ° = ҈° ҈㡰 ᨨ鼀 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ  �   �ᆠ盐 �ᆠ�ᨨ

ᨨ � ��鼀ᨨ�ᨨ  mu҈ 矄� q҈ = ҈mv҈ 矄� q  �㡰 ᔼ�矄��   �泐ᨨ m 盐ᆠ 泐  ᔼ u҈ᨨᆠ�泐 ᨨ  m   ᆠᨨ�矄�ᨨ   

WWW.JEEBOOKS.IN

PS-43

Work, Energy & Power

   -  = =    ␔  �矄  �矄 ᆠ 泐 �矄ᨨ � �鼀 

鼀� 盐矄矄��  � �ᆠ矄 ᆠ矄� �犨� �鼀

u æ ҈ ö ҈ ҈  Þ u҈ = çè mu ÷ø = mu҈     ᔼ  v ҈    ᨨᆠ�泐 ᨨ 鼀矄矄 ҈ 鼀   ᆠᨨ�矄�ᨨ   

҈ ҈ u u ´ ҈ m ´ v҈ = m Þ v҈ =     ᨨ鼀⼄盐�ᨨ  �㡰犨 

\

 

矄� q҈ = ҈ 矄� q 

 ᨨᆠᨨ�矄�ᨨ

v

v



v



ᨨ

 =

   

   =  犨     =    ⏌ ҈ \ ⧤쟼 ⏌  = 鼀  㡰   ⧤쟼 ⏌  ҈ \ = \ ⧤쟼  = 鼀 ⧤쟼   黨 b 㡰 犨    =













 ᨨᆠᨨ�矄�ᨨ



҈





盐矄 ᆠᨨ�矄�ᨨ

v -v v + v ҈= ҈ ҈= v +u uv \v҈㦨u졔v \v㦨uv \Dv҈㦨u졔v  Dv㦨uv dp҈ = rA u + v 㡰 u + v 㡰 ᨨ犨 F҈ = dt dp   F =  = rA 盐 - 㡰  盐 -  㡰 dt \ F҈㦨rA u졔v㡰  F㦨rA uv㡰 DF�矄    ᨨᆠ 盐ᨨ �鼀ᨨᆠ盐矄 ᨨ  

꾀 ᆠᨨ�矄�ᨨ

v졔v



  =-ò  

  \ l

= - l

 

҈㡰 ᨨ矄�ᆠᆠᨨ�矄�ᨨ KE�㦨KEf

҈ ҈ ҈ ҈ m ´ � + ´ m ´ 黨 = m ´  + mvB      =  + VB Þ VB =  ҈ ҈ ҈ KEB = mvB = ´ ҈ ´  = ҈J = J   ҈ \x㦨҈ 䰘 㡰㝐 �鼀盐鼀 ��  æ҈ö u ç ÷ u  矄�  q èø 㦨 Þ҈㦨 g g \ u㦨� ᨨ  �� � �ᨨ盐 �ᨨ矄矄  ᨨ �矄├� �ᆠ �泐 ҈  \ ⧤쟼� ��㦨 mu 㦨鼀�  ҈ ⧤쟼 � 㦨 鼀�㡰㦨҈鼀�  ҈  mv 㦨҈鼀� \㦨� \  꾀   ᨨ盐 ᆠ  鼀 �鼀盐鼀 ��    ᆠ 矄 æ҈ö  g ´ ç ÷ v  矄�  q èø \ ¢㦨 㦨 㦨鼀 g g   㡰

ò

\

�矄ᨨ





␔     矄鼀 �ᆠ 鼀ᨨ� � 犨�  ᨨᆠ�泐 v  盐 �ᨨ矄   矄�ᆠ ᆠᨨ�矄�ᨨ  犨�    泐 鼀ᨨ �矄ᨨ 鼀ᨨ� �犨� ᨨᆠ�泐v�ᆠ⼄盐�矄 犨ᨨᆠ�泐v 졔v和ᨨ � ᆠ矄� ᨨᆠ�泐 泐ᆠᨨ�矄�ᨨ �矄v

�鼀�ᨨ  ᨨ ᆠᨨ�矄�ᨨ  犨    �矄ᨨ  �矄    �矄 ᆠ � ᨨ鼀  ᆠᨨ矄   �矄 ᆠ 

= = 矄  ␔ v�矄  矄 ᨨ  �ᆠ �鼀 \ ⼄盐 ᆠ泐ᨨ犨 �ᆠ  �ᆠ矄�├矄 �矄ᨨ

 㦨 

  ᨨ ᆠ  � ᨨ  矄  ᨨ   �ᆠ  = 㦨 ⼄盐 ᆠ泐㡰맔     \  = 



DF P= = ruv ҈ DF = F҈ - F = rAuv \ A

  ᨨᆠFnet㦨FDF㦨ma \FrAuv㦨ma ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ 犨 ᨨ ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 m҈u҈졔mu㦨m҈v҈졔mv ҈맔u҈졔�맔㦨҈ 㡰졔� v㡰 Þu҈㦨졔�v  �㡰

 ᆠᨨ �ᆠ�  ᨨ 矄�盐��ᨨ

v - v҈ v - -㡰 Þ ҈= u u҈ - u  ҈  Þu҈㦨v졔  ��㡰 ᨨ鼀⼄ �㡰 ��㡰u҈㦨鼀⏌矄 v㦨҈鼀⏌矄  ᆠᨨ鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀㦨├�鼀⏌矄 ⧤쟼ᆠ鼀㦨䰘� e=

WWW.JEEBOOKS.IN

EBD_8341 PS-44

Physics

҈  㡰 ᨨ鼀犨 ᨨ ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀

� ��� 鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 p�ˆ - p�ˆ =  \ � � 鼀ᨨ鼀 盐鼀矄 ᨨ盐 矄ᨨ ᨨ�.e.p҈¢졔p¢㦨 졠�ᨨ  p҈¢졔p¢ = a҈ + a 㡰�ˆ + b҈ + b 㡰 ˆ + c҈kˆ 㦨 �  鼀ᨨ鼀 盐鼀 ᔼ�矄��  ҈҈ᆠ҈ ᆠ  ᨨ 㜠 ᨨ盐矄 ᔼ ҈㦨  㦨 꾀矄ᨨ� ҈㦨泐 㦨泐   

ˆ�   ˆ ᆠᨨ鼀ᨨ  矄ᆠᨨ鼀 ᨨ盐  � 鼀 � � ├ˆ  ᆠᨨ鼀ᨨ   �矄 ᨨ 㜠 ᨨ �矄 ��矄   � � �  鼀ᨨ鼀 盐鼀 ᨨ   矄泐矄鼀 犨 �ᆠ  �ᨨ矄 ᆠᨨ 矄�ᨨ  ᨨ � 鼀ᨨ鼀 盐鼀 矄ᨨ �矄�矄 犨ᨨ �ᨨ�ᨨ  졠�ᨨ   p҈¢졔p¢㦨 a҈ + a 㡰�ˆ + b҈ ˆ ¹ᆠ盐矄b҈¹ ᨨᨨ犨� �   矄鼀 矄ᨨ � � 矄 ᨨ   ᨨ�ᨨ   �矄 矄ᨨ 犨ᨨ �  b 㡰 盐矄     ᆠᨨ�矄�ᨨ  ᨨ C 犨�  A C 矄ᨨ矄  Aᆠ⼄盐�矄ᨨᆠ�泐vᆠ盐矄ᨨ   㜠ᨨ 矄�ᆠᆠᨨ�矄�ᨨ

犨  �  �ᆠ 鼀矄矄矄

␔   A 矄矄 鼀ᨨ� � ᨨ犨 矄 ��    矄� � 矄盐   ᆠᨨ鼀矄矄�ᨨ  盐 ᨨ 犨 �ᆠ  B 矄ᨨ 矄矄 鼀ᨨ� � ᨨ犨 矄 ��  ᆠᨨ鼀矄矄�ᨨ ᨨ  矄� �ᆠᨨ � 盐矄� �矄 � ᨨᆠ�泐 犨  A    B ␔    �矄 � ᨨᆠ�泐ᆠᨨ鼀矄 ᨨᨨ A  B 鼀ᨨ犨�   矄鼀 ᨨᆠ�泐 vἘ     矄� � �矄 �   矄 ᨨ  鼀 �鼀盐鼀 ᆠᨨ鼀矄矄�ᨨ  矄泐 x 㦨 ᔴ

 

Ἐ

Ἐ





㝐 ᆠᨨ鼀矄矄�ᨨ 

ᨨ鼀 � ᆠ� ᨨ ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 v mv㦨mvἘ졔mvἘ Þ vἘ㦨  \ ⧤쟼ᨨ AB矄泐矄鼀鼀 �鼀盐鼀ᆠᨨ鼀矄矄�ᨨ 



҈ ҈ mv  æQ v Ἐ = v ö mv Ἐ + mv Ἐ = mv Ἐ = çè ÷ ø    꾀泐� �  �泐ᆠᨨ 矄�ᨨ

҈  ҈ ҈ ҈ mv = mv Ἐ + mv Ἐ + Kx      ҈  ҈  ҈  Þ mv = mv + Kx    m ҈  ҈  Þ x㦨 v Kx = mv \  K   㡰  v¢    矄  ᨨ  ᨨ  �ᆠ ᨨ  矄      ᆠᨨ�矄�ᨨ  꾀矄 ᨨ �ᆠᆠ矄 �矄  矄 ᨨ  �矄�ᆠ盐矄    ᨨ矄�ᨨ  矄 ᨨ盐   v ᆠᨨ矄 q  v

v矄� q q



h

D



ᔴ 꾀



A



㦨



꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀    �� 矄 ᨨ�  m m m vᆠᨨ矄 q 㡰㦨 ´ v¢ - ´ v ᆠᨨ矄 q   \ v¢㦨vᆠᨨ矄q  ᆠ 㡰ᔼ � 矄�ᆠᆠᨨ�矄�ᨨ ᨨ 泐鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 鼀泐鼀�  ᆠᨨ 矄  㡰 �矄 � ᆠᨨᆠ ᆠ盐矄   鼀ᨨ鼀 盐鼀 ᨨ  ᆠ  �矄 � 鼀� �盐 矄 犨矄 �ᆠ�ᨨ  㡰 �矄 � ᆠᨨᆠ ᆠ盐矄 ᨨ  ᆠᨨ�矄�ᨨ  矄ᨨ鼀 鼀ᆠ  �ᆠ  �泐�矄 ᆠᨨ   � ᨨ  矄ᨨ盐   �泐 ᆠ㡰 �矄 ᆠᨨᆠ ᆠ盐矄 ᨨ   졔  矄泐矄鼀  �鼀ᆠ ᨨᆠ�矄   �   ᨨᆠ 㡰 �矄 ᆠᨨᆠ ᨨ  �泐ᨨ          �矄 ᆠᨨ 矄  � b㡰 꾀矄   � ᆠ�     �矄 �ᆠ�ᨨ 矄矄

⧤쟼㦨쟼A ҈   mv = mgh Þ v =  gh 

졔 m



B

vᆠᨨ矄   v矄�   = �

 鼀



ᔼ DADB  㦨 \ h㦨鼀

C

 鼀



\v㦨 � =  鼀 ⏌ 矄

�矄 �矄 ᨨᆠ�泐ᨨ  ᨨᆠ├盐矄 ᨨᆠᨨ�矄�ᨨ 

�矄ᨨᆠ�泐鼀├矄  �ᨨ  犨�  �ᆠ 꾀矄ᨨ �  ��   �  � � BEC ÐEBC㦨  

 ᨨ 鼀├矄    �ᨨ   犨�    矄ᆠᨨ � ᆠ�   BC ᆠᨨ鼀ᨨ  ᨨ ᨨ �BC�矄v ᆠᨨ矄  ᔼ�矄��   ᆠᨨ�矄�ᨨ B�矄 ᆠ泐� 矄�ᆠ   ᨨ   �鼀ᆠ ᨨᆠ矄 ᆠ ᨨ鼀 ᨨ     矄盐ᆠ   �ᆠᆠᨨ鼀ᨨ  ᨨ ᨨᆠ�泐ᆠᨨ鼀矄 ᨨ  ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐 ᨨ �   � ᆠ�  BC鼀� 矄盐 ᆠ  �   �矄 ⼄盐ᨨv ᆠᨨ矄 

 ҈ = = � 鼀 ⏌ 矄   ҈ BE BE Þ = Þ BE = 鼀  b㡰 ᔼ D BCE   = CE    ᨨ鼀 鼀ᆠ  �ᆠ  �泐ᆠᨨ 矄�ᨨ  � ᆠ� 㝐ᆠ  �ᆠ  �泐B㦨 鼀ᆠ  �ᆠ �泐 C  ҈ ҈ M � + M ´ ҈ ´  = Mvc   㦨  ´

( )

\vc㦨 ҈� 鼀 ⏌ 矄 䰘 ᆠ㡰  ᨨᆠ�泐 ᨨ    ᨨᆠ├ ᨨ � BC 盐矄  ᨨ ᆠᨨ�矄�ᨨ �矄ᆠᨨ矄   �鼀ᆠ ᨨᆠ矄ᆠ �ᆠ盐 ᨨ   矄盐 ᆠ 矄ᨨ   ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐 ᨨ �   � ᆠ�  鼀� 矄 盐 ᆠ  �  �졔㦨 vc 

vᆠᨨ矄q

vᆠᨨ矄q

v' m 

m 

vᆠᨨ矄q

WWW.JEEBOOKS.IN

PS-45

Work, Energy & Power

v矄�  v

B

 vᆠᨨ 矄



C

盐矄 ᆠᨨ�矄�ᨨ

꾀矄ᨨ 矄� ᆠ   ᆠᨨ�矄�ᨨ  �矄 矄�ᆠ   �ᆠ ᆠᨨ鼀ᨨ   ᨨ ᨨᆠ�泐 v矄�  㡰 ᨨᆠᨨ�矄�ᨨ ᆠ  �矄�  �ᆠ�ᨨ   鼀� �盐 鼀� � � 矄鼀矄矄 ᨨ犨 �   ��盐 和ᨨ   ᆠ �盐 ᆠᨨ鼀ᨨ  矄 ᨨ  ᨨᆠ�泐   ᆠᨨ�矄�ᨨ

矄矄 ᨨ犨 �   ��盐 �矄鼀 矄   � ᨨᆠ�泐 ᨨ  ᨨᆠ├矄 ᨨ盐  ᨨ� ᨨ 鼀├� �  �º犨� BC  ᨨ   �ᆠ ᆠᨨ鼀ᨨ   ᨨ   �  ᨨᆠ�泐 ᨨ  ᨨᆠ├ �矄 ᨨ 

㡰 㝐 �鼀盐鼀 �泐ᨨ矄矄㦨

  鼀  鼀 + 㝐㡰 é  ҈  ù = 鼀 ú êQ ⧤쟼 = 鼀  ëê ûú

 é 㝐 ù ҈ ì 㝐 ü = 鼀  í ý ê ú 鼀 ë 鼀 + 㝐㡰 û  î鼀 + 㝐 þ 和鼀  ᔼᔼ �矄  ᆠ矄 ᨨ  ᆠ泐� 矄�ᆠᆠᨨ�矄�ᨨ  泐ᆠᨨ鼀� � ⼄盐�ᨨ �� � 矄鼀 ᔼ犨� ᨨ ⼄盐�ᨨ  犨 �\ æ 㝐 ö æ 鼀 ö =ç � 矄  ᨨ  ÷ ç ÷ è 鼀 + 㝐ø è㝐+鼀ø  ᆠ 矄鼀  ᔼ �矄 犨ᨨ �   矄鼀  ᔼᔼ�矄 ᆠᨨᆠ 㡰 和鼀 ҈ ᨨ 矄�ᆠᆠᨨ�矄�ᨨ  ᆠᨨ �ᆠ�  ᨨ 矄�盐�ᨨ 㦨 ҈  v - v҈  Þ vv҈㦨u҈u e㦨  u҈ - u  Þ � ᨨᆠ�泐   ᆠᨨ�矄�ᨨ  �矄 ⼄盐 ᨨ � ᨨᆠ�泐 ᨨᆠᨨ�矄�ᨨ 盐�  矄鼀 �矄 �矄 ��  和鼀 � 鼀ᨨ鼀 盐鼀鼀� 矄ᆠᨨ 矄 � 

矄�ᆠ ᆠᨨ�矄�ᨨ  �矄 矄鼀  �矄 盐 ᨨ鼀PᨨQ ෌�  u㦨҈鼀⏌矄 m㦨�錐s㦨鼀 é mg 矄� q + f ù é mg 矄� q + mmg ᆠᨨ矄 q ù = -ê a㦨 - ê ú úû m m ë û ë =

黨



R

M uA

鼀

Q

N m mg矄� q

q mgᆠᨨ矄q P mg f q

㦨᲼g矄� q 졔Ҙgᆠᨨ矄 q 桌㦨g᲼矄� q 졔Ҙᆠᨨ矄 q 桌 㦨҈᲼�졔�맔黨黨桌㦨黨黨鼀⏌矄 矄� �vu㦨as Þ v㦨҈졔 黨黨㡰맔Þ v㦨鼀⏌矄

 ᆠᨨᆠ�泐ᨨ 鼀矄矄 m盐矄 ᨨᆠᨨ�矄�ᨨ 㦨鼀⏌矄

ᨨᆠ�泐ᨨ 鼀矄矄M盐矄 ᨨᆠᨨ�矄�ᨨ 㦨鼀⏌矄 �� 㡰  v҈  ᨨᆠ�泐ᨨ 鼀矄矄 m ᆠᨨ�矄�ᨨ    v    ᨨᆠ�泐 ᨨ  鼀矄矄 M   ᆠᨨ�矄�ᨨ  ᨨ y ᨨ  鼀矄矄 M 鼀ᨨ� � ᨨ鼀QᨨR ᆠᨨ鼀� �ᨨ矄꾀 ᆠᨨ�矄�ᨨ  u㦨v v㦨 a㦨黨黨鼀⏌矄 s㦨� 

vu㦨as Þ 㡰 v 㦨 黨黨㡰맔� Þ v㦨҈䰘鼀⏌矄 ᨨ yᨨ 鼀矄矄m鼀ᨨ� � ᨨ鼀QᨨP ᆠᨨ�矄�ᨨ

h   S㦨 h㦨矄�  q 㦨矄�  㦨맔� q P u㦨v҈ v㦨졔҈鼀⏌矄 ⧤쟼졔쟼㡰� ��㦨 ⧤쟼졔쟼㡰 � 졔␔ �ᆠ�ᨨ

҈  ҈ mv҈ + mgh = mv  +  + m mgs   ҈  ҈ v҈ + ҈ ´  ´ �㡰 = ҈㡰  + � ´ ҈ ´    v҈㦨�鼀⏌矄 \ ᔴᨨ �ᆠ�  ᨨ  矄�盐�ᨨ

矄� q =

e㦨

Q h

� ᨨᆠ�泐 ᨨ 矄�ᨨ

� ᨨᆠ�泐 ᨨ ᨨᆠ

-� - ҈䰘 =  - 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀  ᨨ    ᆠᨨ�矄�ᨨ  mv졔M맔㦨m맔v҈졔m맔v 맔졔M맔㦨맔 �㡰졔M ҈䰘㡰  = ҈� ├� \ M㦨 ҈䰘 ҈ ␔     矄ᨨ  ᆠ 矄   ᨨ�  B   ᆠᨨ鼀ᨨ   ᨨ ᨨᆠ�泐�   졔Z �ᆠ�ᨨ  vᆠᨨ矄 q㡰ᆠᨨ鼀矄 ᨨ 盐ᨨ   ���ᨨ  ᨨᆠ �    Z �ᆠ�ᨨ  㦨

Z

졔Z

졔Y v

vᆠᨨ矄q q v矄� q A vx 㦨m t 㦨

L

B

v' Y

vx 㦨鼀⏌矄

X t=t

 矄ᨨ  矄 犨ᨨ ᨨᆠ��矄  B vx�  졔X �ᆠ�ᨨ  鼀⏌矄㡰 v矄� q �  졔Y �ᆠ�ᨨ  矄�  㦨鼀⏌矄㡰 矄盐  ᨨᆠ�泐ᨨ   矄ᨨ      vἘ㦨 v x 㡰 + v 矄� q㡰 㦨  +  = �鼀 ⏌ 矄 �㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀  B ᨨ ᆠᨨ�矄�ᨨ 犨� 鼀矄矄 ᨨ ⼄盐 鼀� �盐  和� ᆠ ᆠᨨ�矄�ᨨ �矄ᆠᨨ鼀泐� 矄�ᆠ 犨ᨨ鼀矄矄矄 犨�矄�ᆠ├ᨨ� v�矄 ᨨᆠ�泐ᨨ  犨ᨨ鼀矄矄矄盐矄   ᆠᨨ�矄�ᨨ 桌 m맔�㦨m맔v \ v㦨�鼀⏌矄

WWW.JEEBOOKS.IN

EBD_8341 PS-46

Physics

��㡰 ␔     矄� � �矄 盐 �ᨨ� � ᆠ�ᆠ盐 鼀ᨨ�ᨨ  

Ҙgd 㦨 - Ҙgd �

 �� 矄��  矄 ᨨ犨矄     鼀矄矄 m ᨨ盐 矄 ᔼ    ᨨᨨ犨矄  ᨨᆠ� 鼀ᨨ�ᨨ    �矄  矄 ᨨ�ᆠ uy㦨sy㦨day㦨gty㦨䁸 ᨨ �ᆠ 鼀ᨨ�ᨨ   = - ´ �

mv   泐�泐ᨨ矄��ᨨ Tmgᆠᨨ矄a㦨 l 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ T㦨犨  a㦨黨 mv  Þ v㦨 l �.e.�   ᨨ� ᨨ ᨨ矄��ᨨ v㦨 꾀泐� �  �泐 ᆠᨨ 矄�ᨨ  ᨨ鼀 B ᨨ C a \

㦨

҈ mv  = mg l   Þ l=

d ҈  ҈ at  Þ d㦨 gt   Þ t㦨 g  

 ᨨ� ᨨ  �矄 ᆠ   泐 鼀矄矄 m 盐� �  �矄 �鼀t ᨨ鼀 犨 矄

S㦨 ut +

C

T

v  �㡰  = 㦨҈鼀  g  ´ 黨

mg 矄� a

a

mg ᆠᨨ矄a

mg



d =  Ҙd  㦨 d µ g  ᔼ ��泐犨   ᨨᨨ  盐盐鼀�矄꾀�矄쟼㦨mgl ␔   ᨨ矄  ᨨ鼀꾀 矄�├矄ᨨ 犨 쟼 ᆠ  �矄 ᨨ ⧤쟼   犨   � �矄  ᨨ矄��ᨨ  �ᔴ    �盐鼀�盐 �矄  ᔼ DOCM x㦨  Ҙgd ´

B

졠ᆠᨨ 鼀矄矄mᆠᨨ� 矄犨� ᨨᆠ├Bᨨ 鼀矄矄m 和� ᆠ   ᆠᨨ�矄�ᨨ  �矄 矄�ᆠ �  盐 泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 mv㦨 鼀㡰u졔mv¢ 犨 u�矄 ᨨᆠ�泐ᨨ 鼀矄矄鼀 ᆠᨨ�矄�ᨨ  v¢�矄   ᨨᆠ�泐 ᨨ 鼀矄矄 m Þ v¢㦨vu  �㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  ├� �ᆠ  �泐

҈  ҈ ҈ mv = 鼀㡰 u  + mv Ἐ     m Þ v㦨u졔vἘ  ��㡰 ᨨ鼀⼄ �㡰 ��㡰

v

҈  mvB  Þ vB㦨 gl     n ᆠᨨ�矄�ᨨ 矄    �盐 鼀�盐  �矄   犨 

 ᨨ�� 鼀ᨨ矄ᨨ犨 矄 犨 ᨨ鼀C ᨨᆠ�泐 vἘB  ᨨ ᆠᨨ�矄�ᨨ

mg l =

m

A

꾀矄ᨨ

l OM Þ OM㦨   l

 ᨨᆠ�泐 ᨨ  ᨨ  B

ᆠᨨ矄 㦨

B

m

d

l ҈ = mv ἘB  Þ vἘB㦨 gl  

�矄 鼀 矄     ᨨᆠ�泐 ᨨ    ᨨ 矄 ᨨ盐   盐ᆠ

v v㦨u졔 vu㡰 Þ u㦨 � ᨨᆠ├ B 矄矄 鼀ᨨ� � 盐   ᨨᆠ├ A 鼀� 矄  矄 꾀矄  �矄 ᨨ �ᆠ�ᨨ 犨  A  B ᨨᨨᆠ├Aᨨᨨᨨᆠ├B矄 ᨨ盐 鼀ᨨ �矄 ᆠd     �ᨨ  ᨨ 盐ᆠ  �  B 盐 ᨨ  �ᆠ�ᨨ  ᨨᆠ 犨  B      F㦨mN Þ m㡰a㦨m mg㡰Þ a㦨҈�Ҙg ᨨ 鼀ᨨ�ᨨ  ᨨ B u㦨

mg

ᨨ鼀 gl ᨨ

 �  ᨨᆠ�泐 nᆠᨨ�矄�ᨨ 矄 �矄 \

n

m҈㦨mm㦨mu҈㦨 � Ҙgd  u㦨 Þ

҈ æ  ö = ᨨ� nᨨ� ç  Þ n㦨҈ ÷ è �ø 

v=

m҈ - m 㡰 u҈ m u + m҈ + m m҈ + m

v҈㦨

m - m㡰� Ҙgd + m + m

n

g l  Þ  æç  ö÷ = ҈ è �ø 

├� � ᨨ� ᨨ ᨨ  矄� 矄 犨 �



v҈㦨

gl

æ  ö çè ÷ø ´  g l = �

v  v㦨s㦨 a㦨҈�Ҙg �

� µgd  ᨨ 矄�ᆠ ᆠᨨ�矄�ᨨ  犨  犨ᨨ ᨨ �矄

en  g l 㡰 =

gl

犨  e �矄 ᆠᨨ �ᆠ�  ᨨ 矄�盐�ᨨ 

æ v ö ᨨ犨vu㦨asÞ 㡰 ç ÷ =  -҈�Ҙg 㡰 d è �ø Þ

gl  盐ᨨᆠᨨ�矄�ᨨ 矄犨� 犨矄



 ᆠ 盐鼀ᨨ ᆠᨨ�矄�ᨨ 矄㦨 ᨨ� 鼀矄矄 � 犨犨�  矄 v

 ᨨᆠ�泐ᨨ 鼀矄矄m �矄� 矄 㦨vᆠᨨ矄q㦨



v � 盐 M犨�  �矄 ᆠᨨ ҈鼀犨 �m犨��矄盐泐 � ҈㡰鼀 ᨨ鼀 �泐ᆠᨨ 矄�ᨨ ᆠ矄� 쟼ᨨ M㦨� ᆠ矄 � 쟼ᨨ m졔� ᆠ矄� ⧤쟼ᨨ ᨨ  ᨨᆠ├矄

WWW.JEEBOOKS.IN

PS-47

Work, Energy & Power 꾀泐� � 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ 

҈鼀 鼀 졠 ҈鼀



mv㦨mv¢졔mv¢\

v¢㦨

v 

 ��㡰

ᨨ鼀⼄ �㡰  ��㡰

q



h

v -  ´

vᆠᨨ矄q �鼀

v q v㦨v ᆠᨨ矄q

䰘

h' �҈㡰鼀 鼀

mv v k   矄� �ᆠᨨ 矄 㡰 = x Þk㦨 黨 m x

꾀  �� 矄ᨨ� P ᨨᆠ�泐ᨨ  盐㦨uᆠᨨ矄q ᔼ DAQR R �㡰 ᨨ鼀 ��盐

QR � 矄�  㦨 QR㦨 ҈ ⏌  

҈  ҈  Mgh㦨mgh'졔 mv + m  ᆠᨨ矄 q㡰   ҈ ᨨ 㡰 黨㡰 ҈㡰㦨 �㡰 黨㡰 � - ҈㡰 + ´  ´ v  

졠

Y ҈⏌

P

uᆠᨨ矄q

u

R ,H 㡰 



�

æ v ö ҈ 졔 ´ � ´ ç ÷  è �ø 和ᨨ� �犨�v㦨黨鼀⏌矄 ᔼ ��ᨨ矄��ᨨ ᨨ ᔴ㝐 m҈x҈ + m x ҈ ´  + ҈ ´ 黨 x҈㦨 m + m 㦨黨鼀 㦨  ҈  ҈�㦨 ᨨ 㡰 ᔼ �� ᨨᆠ�泐ᨨ ᔴ㝐

q O

Mu ᆠᨨ矄 q u ᆠᨨ矄 q = M  ᨨ鼀 �泐ᆠᨨ 矄�ᨨ � ᆠ�KEᨨ  盐㜠鼀矄矄 矄泐矄鼀P㦨PEᨨ  盐㜠鼀矄矄 矄泐矄鼀R v㦨

m҈u҈ + mu ҈ ´ 黨 + ҈ ´  㦨�鼀矄҈ m҈ + m 㦨  u҈ 꾀ᆠᆠ�ᨨ  ᨨ  ᔴ㝐 ac㦨黨鼀矄 ᔴ㝐 �矄ᆠ鼀 ᨨ ᔴ㝐 �矄 sc㦨黨鼀 꾀泐� � 黨鼀矄҈ ҈  S㦨ut졔 at ҈g  졠 ᨨ��� 㡰 黨㦨�t黨t t�t҈㦨 � ± � +  � ± � t㦨 㦨 㦨�矄    ᆠᨨ�矄�ᨨ 犨 C  A�矄 矄�ᆠ   �鼀矄矄矄  ⼄盐 矄ᨨ  泐 犨�  ᆠ  �  � ᨨᆠ��矄 A 犨矄 � ��泐矄  ᨨ 矄盐ᨨ ᆠᨨ�矄�ᨨ 犨�  C犨�ᆠᨨ鼀ᨨ矄 A犨�� ��泐矄鼀ᨨ� �犨�  ᨨᆠ�泐v 盐 矄� ᆠ A �矄 ᆠᨨ

ᆠ ᨨ B 犨�   矄� �   矄� � 犨� � ᆠᨨ鼀矄矄  v¢  ᆠᨨ鼀鼀ᨨ ᨨᆠ�泐ᨨ A  B m v



A m

B m

㦨

C

A m

҈ M 㡰v  =  M 㡰 gh 

k  x m

黨 ´ � ´  ´ ҈ Þ q 㦨䰘 � ´ � Qu㦨�鼀⏌矄�� 㡰 ��㡰 �ᆠ ᆠᨨ鼀ᨨ   ᆠᨨ矄 q 㦨

R u  矄� q � ´ �矄�  ´ 䰘o = = = ҈ 鼀  g  ´ 黨 ᨨ� ᨨ  ᆠᨨ鼀ᨨ   H㦨

u  矄�  q � ´ � ´ 矄� 䰘°㡰 = =  鼀 g  ´ 黨



mV A

C

G

vἘ

҈  ҈ ҈ ҈ mv = mv Ἐ + mv Ἐ + kx     犨 x�矄 ᆠᨨ鼀矄矄�ᨨ �  矄� �t㦨t

v = v Ἐ +

҈ u  ᆠᨨ矄 q æ ҈ � ö M 㡰 = Mg ´ ç + ÷ è  ø  ҈

vἘ B m

꾀t㦨t ᨨᆠ��矄ᨨ A Bᆠᨨ鼀矄鼀 꾀泐� �  �泐ᆠᨨ 矄�ᨨ 錐

\

 �㡰

X

ᨨ犨 ᨨ鼀ᆠᨨ 矄�ᨨ ᨨ � 鼀ᨨ鼀 盐鼀  �� 矄 ᨨ� 㜠 M uᆠᨨ矄q㡰졔M맔㦨 M졔M㡰v

uc㦨

C

Q

A

B B

C

 ᨨᆠᨨ�矄�ᨨ

mV

꾀 ᆠᨨ�矄�ᨨ

 ᨨ ᆠᨨ�矄�ᨨ  泐 矄泐鼀鼀泐    鼀ᨨ鼀 盐鼀 ᨨ    矄泐矄鼀 �矄 ᨨ 꾀 ᆠᨨ�矄�ᨨ 鼀ᨨ鼀 盐鼀�矄矄ᨨ ᨨ矄 ᨨ矄  ᨨᆠ �矄ᆠ� �ᨨ  矄泐矄鼀꾀ᆠᨨ鼀矄ᨨ矄矄ᨨ ᔴ矄 ᨨ盐 ⼄盐 ᨨᨨ矄�鼀ᨨ鼀 矄ᨨᨨᆠ�泐ᨨ C矄 ᨨ盐  矄鼀 �  鼀� �盐  �.e. V 盐 �  ᨨᨨ矄� �ᆠ�ᨨ  ᨨ ᨨᆠ�泐ᨨ B

WWW.JEEBOOKS.IN

EBD_8341 PS-48

黨

Physics

꾀泐� �ᆠᨨ 矄�ᨨ ᨨ � 鼀ᨨ鼀 盐鼀 ᨨ 矄泐矄鼀 ᨨ 盐 Amv㦨mv҈졔m҈v  �㡰 ᨨ v㦨v҈졔҈맔v

㦨

m㦨├�



v

Topic-5 : Miscellaneous (Mixed Concept) Problems

v

҈ v

ᨨ

꾀��  泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 ᨨ ᆠᨨ�矄�ᨨ B mv҈㦨 m졔m㡰v ᨨ v҈㦨 黨졔㡰v㦨v

 v҈  ᨨ鼀⼄ �㡰  ��㡰 Þ v㦨

t

\s㦨 v ò e

 v  = Þ v㦨 v҈ Þ  v҈ 

t ⏌ t

R

奠ᨨ矄矄� ᨨᆠ�泐

v v  q = wt =  t R R $ vp㦨 (  v 矄� q� + v ᆠᨨ矄 qˆ )

pf㦨 mV  + M v 

ᨨ

Mv ҈ Mv Þa㦨 

mV mV 犨 �ᆠ  ��矄   �ᆠ�ᨨ  ᨨ   鼀ᨨ鼀 盐鼀

y r pf a

æ è

vp㦨 ç  v 矄�

x



éæ v ö $ æ v ö ù 㦨 m êç v 矄� t ÷ � + ç v ᆠᨨ矄 t  v҈ ÷ ˆ ú ø û R ø è R ëè 㡰 ᨨ ᆠ�ᆠ盐 鼀ᨨ�ᨨ  ᨨ       ᆠ矄矄泐 ᆠ � ᨨᆠ �矄 ᨨ�   泐 mg ᆠᨨ矄 q  N㡰 mgᆠᨨ矄 q N㦨

Mvˆ

⧤쟼 �

p f m + M 㡰 ⧤쟼 f ҈  㦨҈  㦨 ҈ ҈ ⧤쟼� mV  + Mv   

 

㦨҈ 

 

m V +M v

m + M 㡰 mV  + Mv  㡰

v $ v ö t� + v ᆠᨨ矄  tˆ ÷ R R ø

 vm㦨 v҈ ˆ \ � 鼀ᨨ鼀 盐鼀ᨨ �ᆠ犨鼀 矄  盐 ᆠ�ᨨ

ᨨ �鼀 Lpm㦨m vpvm㡰

 a㦨

mV�ˆ

x

t㦨

w㦨

�  ᨨ 泐㡰

��㡰

ds 㦨vet⏌t Þds㦨ve⏌tdt dt

dt 㦨vt ҈e҈㡰㦨�맔맔㦨鼀

v - v҈ = � v

⧤쟼 �  ⧤쟼 f

҈ J = 㦨�鼀矄҈ m 

꾀 �盐矄  ᨨ �ᆠᨨ盐ᆠ ᨨ  ᆠ�ᆠ盐 y v v q

҈ v - v҈ 맔҈㦨 ´ ҈ = �奠  v �㡰꾀ᆠᆠᨨ � � ᨨᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 r r p f 㦨 p� 㦨 mV�ˆ + Mvˆ  㝐� �盐 ᨨ  鼀ᨨ鼀 盐鼀ᨨ \

㦨





v҈  v  ҈ = Þ ҈ - ҈ = ҈ - = = � v  v  

\

㦨鼀Þ

꾀矄ᨨ 㡰㦨ve⏌t \

 ��㡰

 v҈ v㦨v҈졔 

�

㡰 ෌� 鼀矄矄m㦨├�錐�鼀盐矄㦨҈矄 t㡰㦨 vet⏌t錐t㦨矄 e҈㦨䰘 ᔼ鼀盐矄㦨ᔴ  �� � 鼀ᨨ鼀 盐鼀

m㦨黨├�

m ҈㦨҈├�

Þ

m + M 㡰 mV  + Mv  㡰

DK  E mM v  + V  㡰 㦨 K  E� m + M 㡰 mV  + Mv  㡰

B

A

mV  + mMv  + mMV  + M v   m V   M v 

mv   �㡰 dö æ R + çè ÷ ø

B C A D

N㦨 ᨨ鼀ᆠ�ᨨ  �q 꾀ᆠᆠᨨ � � ᨨ  �泐 ᆠᨨ 矄�ᨨ

R

mgᆠᨨ矄q

q

NA

d⏌

q

V

mg矄� q

mg

dö ҈  æ mv = mg ç R + ÷ ҈ - ᆠᨨ矄 q㡰 è  ø dö æ Þ v㦨� ç R + ÷ ҈ᆠᨨ矄q㡰 ø è

WWW.JEEBOOKS.IN

PS-49

Work, Energy & Power 盐� � �矄盐ᨨ v� ⼄ �㡰 N㦨mg ᆠᨨ矄 q 㡰 㡰 犨�ᨨ矄ᆠᨨ ᆠ犨�  �

矄 犨 

N㦨

æ ö è ø 꾀   �矄 � 鼀├矄 ᆠᨨ ᆠ 犨�  ᨨ盐 矄    ᨨ鼀 ᆠ�ᨨ  矄矄 ᆠ� � ᨨ犨 矄   ᆠ 

ᨨ

ᆠᨨ矄q㦨ᨨq㦨ᆠᨨ矄҈ ç ÷

和ᨨ ᨨ

æ ö è ø

q £ᆠᨨ矄҈ ç ÷

\ ux㦨҈ᆠᨨ矄 졔 �  㦨 ��  \ 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 ᨨ   ᆠ

ᨨ  㜠ᨨ泐 矄泐矄鼀 �  ᨨ� ᨨ  �ᆠ�ᨨ  mux졔M맔㦨 m졔M㡰vx

mu x 犨  m 㦨 鼀矄矄 ᨨ ᆠ



m+M M㦨鼀矄矄ᨨ ᨨ泐vx㦨ᨨᆠ�泐ᨨ  ᆠ

ᨨ 㜠 ᨨ泐 矄泐矄鼀㡰

\

vx㦨

҈´ ��  = ��  鼀矄 ҈ ҈+ 黨 ᨨ� ᨨ  �矄 ᆠ ᆠᨨ  泐   ᆠ

\

NB㦨 NA㦨mg ᆠᨨ矄q㡰



ᨨ� ᨨ  ᆠᨨ鼀ᨨ   ᨨ  ᨨᆠ�泐 ᨨ    ᆠ

ᨨ   鼀� 矄   矄鼀

æ ö  ᨨ q ÷ è ø NA㦨  NB㦨mg ᆠᨨ矄q㡰

NAᆠᨨ矄q NBᆠᨨ矄q� 矄矄 ᨨᨨ犨矄 ³ᆠᨨ矄҈ ç

NB �鼀�

NA

vx 㦨

P 㦨 ҈ 맔  �  =   鼀  Q 和ᆠᨨ   犨矄 ᨨᆠ    ҈ 矄ᆠᨨ 㡰 和� ᆠ   矄ᆠᨨ   矄ᨨ 矄盐ᆠ├   ᨨ泐 \ �  �鼀 ҈ 矄ᆠᨨ 矄   ᨨ泐 ᆠᨨ矄  �矄 ᆠ ᨨ

  鼀 ᨨ ᨨ泐   ҈ 矄ᆠᨨ 矄錐

u = �  鼀⏌矄 v㦨䁸 t㦨҈矄 m

mg

s㦨   鼀 鼀�





⏌

ᆠᨨ矄q

졔҈



⏌ 졔҈

s㦨 ut +

ᆠᨨ矄q

ᔴᨨ 矄�   �ᆠ 鼀ᨨ�ᨨ  ᨨ   ᆠ

ᨨ   uy㦨졔҈矄�   �ᆠᆠᨨ鼀ᨨ  ᨨ ᨨᆠ�泐㡰 sy㦨҈鼀 �ᆠ �矄ᆠ鼀 㡰  ay㦨҈鼀⏌矄

A

m 㦨黨├� B

u 㦨 T

t 㦨t �鼀ᨨ  �矄�鼀ᆠᨨ ᆠ��㡰 ҈ 



sy㦨uy t + a y t  \҈㦨�t� t

Þ \ \

t ҈t㦨

-҈㡰 ± ҈ -  ҈㡰 -㡰 㦨҈ᨨ᲼ᨨ� 桌 t㦨  t㦨҈矄ᆠ

҈  at 

҈   㦨 ��  맔҈졔 맔a맔҈ 

\

 a㦨   ⏌ ҈ 鼀矄 \v㦨u졔at㦨 �  鼀⏌矄

æ ö v㦨u졔at㦨 ��   çç ÷÷ ´҈ è ҈ ø

ux

C

ux

Þ

졔 P uy u ᨨ 힘

҈m

M

v㦨 �  鼀矄 ҈

ᨨ �   � ᨨᆠ�泐vfᨨ  ᆠ��  矄ᆠᨨ �鼀ᆠ 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 �    ᨨ� ᨨ  �ᆠ�ᨨ

mux졔 M졔m㡰vx㦨 M졔m㡰vf \

҈맔 ��  졔 黨졔҈㡰 �  㦨 黨졔㡰vf vf 㦨҈�䰘�鼀⏌矄

WWW.JEEBOOKS.IN

EBD_8341 PS-50

Physics

System of Particles and Rotational Motion

6

㝐矄矄 ᨨ 鼀� � �

Topic-1 : Centre of Mass, Centre of Gravity & Principle of Moments ҈

   pR r  p ҈㡰 r   ᔴ ᨨ 鼀矄矄ᨨ 鼀� � �  M r + M  r X ᔴ졠㝐 = ҈ ҈ M҈ + M  M 鼀� � �㡰 =

b㡰 ෌� 

æxö ÷ èLø

�  鼀矄矄  矄�泐 r x 㡰 = a + b ç

X CM =

ò xdm ò dm



é  ù é ù  êë  pR rúû  + êë  p ҈㡰  r㡰 úû ᲼ R ҈桌 Þ    R 㡰 =    pR r + p ҈㡰 r㡰  

L

ò dm = ò r x㡰dx  Lé

æxö = ò êa + b ç ÷ èLø ê ë



Þ



bL ú dx = aL +  úû L Læ æ aL bL ö bx  ö xdm = ax + dx = + ç ÷ ç ÷ ò òç ç   ÷ø L ÷ø è  è æ aL bL ö + çç ÷   ÷ø è \ X ᔴ㝐 = bL aL +  L æ a + b ö Þ X ᔴ㝐 = ç ÷  è a + b ø b㡰

R ҈㡰 

R ҈㡰

=  R

Þ

R ҈㡰 R ҈㡰 R  + R + ҈㡰

= R

Þ R졔R졔҈㡰 R㡰㦨҈ 



Xcm =

X cm

m҈ x҈ + m x + m x m҈ + m + m ҈ ´  + ҈� ´  + � ´  ҈� ´  = = = 黨cm ҈ + ҈� + � �

m y + m y + m y Ycm = ҈ ҈ m҈ + m + m ҈ ´  + ҈� ´  + � ´  � ´  Ycm = = = cm ҈ + ҈� + � �  ᆠᆠ ᨨ 鼀矄矄ᨨ 矄泐矄鼀 �矄ᨨ�  黨㡰 ᨨ�� 鼀�  x y m҈㦨҈C҈㦨 ҈��㡰 m㦨C㦨 �҈�㡰 m x + m x ҈� + ҈� = = 䰘� X cm = ҈ ҈ m҈ + m 

m҈ y҈ + m y � + � = = ҈䰘� m҈ + m  \ ᔴᨨᨨ �  ᨨ ᆠ  ᨨ 鼀矄矄 ᨨ  � 矄  鼀�  䰘�҈䰘�㡰 㡰 㝐矄矄 ᨨ  矄  㦨 ᨨ盐鼀 ᨨ  矄    矄�泐 ᨨ 矄 

�

=

  p r 

㝐矄矄 ᨨ  ᆠ�泐 M ᆠ�泐 =

 p ҈㡰 r 

m㡰aˆ + m ´ a�ˆ + ma -�ˆ㡰 + m ´ a - ˆ 㡰 m + m + m + m a�ˆ - aˆ a ˆ ˆ = = � -  㡰 ҈ � 㡰 ␔� 矄ᆠ ᨨᨨ�  q  ᔴ㝐 ᨨ  ᆠ盐㜠ᨨ  ᨨ�ᨨ

æa bö ç  ÷  è  ø MX - mx 矄� � xᔴ㝐 = M -m M a M ´- ´   =- a = M ҈ M =

Ycm =



㡰 꾀ᆠᆠ�ᨨ  ᨨ  ᆠ  ᨨ  鼀矄矄 aᆠ鼀㡰 �矄 ��  泐 r r m a + m a +  r \ aᆠ鼀 = ҈ ҈ m҈ + m + 



WWW.JEEBOOKS.IN

PS-51

System of Particles and Rotational Motion

b ҈ 和ᨨᔴ㝐 ᆠᨨᨨ � 矄 ᨨ   yCM = -

҈

a a �a - =  ҈ ҈ b b �b =   y =  ҈ ҈ ᆠ㡰 ᨨᨨ 盐ᆠ鼀 �鼀盐鼀鼀ᨨ鼀  ᨨ  ᨨᆠ� ᨨ ᆠ�ᨨ

ᨨ  ᨨᆠ鼀盐矄 �ᆠ盐ᨨ� 꾀

ᆠ㡰 ᔴ ᨨ 鼀矄矄 xᆠ鼀

x =

䰘

꾀 q



黨

҈҈

h D

B

O

C

h

C

h

h'

B

P

B D = h' - h = OB - OP = OC - OP ҈ æ ö = h - h = h  - ҈ = h -҈ ç æ pö ÷ ç ᆠᨨ矄 çè ÷ø ÷ è ø n

(

)

 ᆠ ᨨ 泐盐ᨨ  n D = h

҈ æ ö -҈ ç æ pö ÷ ç ᆠᨨ矄 çè ÷ø ÷ è ø n



ydy

h

y

 �㡰

a

dy h

r 

R



h

é y ù ê ú  ë  û ycm㦨  㦨 h 㦨    h h ҈ b㡰 ᔴ  ᨨ  鼀矄矄 ᨨ    ᨨ  �矄 ��  泐  ò  y dy

ò ax +

 L

bx 㡰 dx L bx

ò a + L 㡰dx  

A O

h 

ò r 㦨 

ò ydm ò dm

҈  ҈  pR hr R h   ᨨ ᆠᨨ 犨├ ᨨ犨  r y y = \r㦨 R R n n

xcm =

B

D D

dyr

L

n㦨㡰 OD 㦨h 矄ᨨO�矄 ᆠ ᨨ� OA h Ἐ  = = Q OA = OB = h Ἐ㡰 \ OD h ҈ Þ h'㦨h æ ҈ ö æ ҈ ö D = h Ἐ- h =  h - h = h ç -҈ = h -҈ ç p ÷ è ҈ ⏌  ÷ø çè ᆠᨨ矄 ÷  ø ᨨ犨ᆠᨨ 矄� 矄⼄盐 n㦨㡰

h

㦨





h'

O

C

ò y pr





㡰   矄�泐ᨨ  ᆠᨨ  㦨 r

h

O



 㡰

q

 ҈ \  q = =   ᆠ㡰 꾀ᆠᆠᨨ � �ᨨ� ᆠ�ᨨ 鼀ᨨ鼀 矄犨  矄泐矄鼀�矄 矄 ᨨ  ᆠ    �㜠ᆠᨨᆠ├犨�矄 鼀ᨨ鼀  �矄 ⼄盐 ᨨ ᆠᨨᆠ├犨�矄 鼀ᨨ鼀  �ᨨ 맔ᨨ 鼀㦨 ᨨ맔 ᨨ鼀 ␔   �鼀� 犨��  �矄 ᆠ  ᨨ  鼀 矄 � 矄 ᨨ  矄�   ᆠ  鼀 ᆠᨨ鼀矄 矄 ᨨ    ��  鼀 b㡰 ᔴᨨ 矄�  矄�鼀矄 ᨨ泐�ᨨ  � � � A A C



Bc y ҈ +  \ = = ҈䰘 AB x 



鼀

æ x ö҈ rx 㡰 ç ÷ + ry y ⏌ èø r x + y 㡰

҈ y y + =  x x

Þ

ᔴ ᨨ 鼀矄矄ycm㦨

鼀

x = 

A

aL bL L æ a + b ö + ç ÷  = è  ø =   bL b aL + a+   a b + 䰘L   = ᨨ犨 b ҈ a+  졠  矄ᨨ� � 犨 � b 㦨 a ҈ ᆠ㡰 ҈ 㡰 ҈ 㡰  犨� � ��  �    ��盐 �矄 鼀  盐 ᨨ  � ᨨ �矄 �   ᆠ�ᆠ矄   犨ᨨ 矄��  �  ᨨ  盐 � ᨨ鼀 鼀矄矄 �矄�盐�ᨨ ᨨ犨ᆠ 矄矄盐鼀 矄泐矄鼀ᨨ鼀  盐 ᨨ  � ᨨ�  鼀矄矄矄 犨    鼀矄矄 ᨨ ᆠ  �矄 ᆠᨨ 矄�     �矄 �ᨨ鼀�ᆠ ᆠ  Y a a㡰 m

m

Y

m 㡰

a㡰 m

a a㡰 m

a  a㡰 m

a a㡰

X

m

㡰

X

m a㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-52

҈�

҈

Physics

 泐㜠ᆠᨨᨨ �  ᨨ   ᆠ  ᨨ 鼀矄矄 �矄 m y + m y + m y + m y + m� y� ycm = ҈ ҈ m҈ + m + m + m + m� m ´  + m ´  + m ´ a + m ´ a + m - a 㡰 \ ycm = m + m + m + m + m ma a =  = ҈ m ҈ 㡰 㝐盐盐 ᨨᆠᨨ ᆠ�ᨨ 犨� 犨 �ᆠ 犨ᨨ�ᆠ矄꾀    鼀ᨨ ᨨ犨 矄 ᆠ  ᨨ  �矄  �   ᨨᆠ   ᨨ    ᨨᆠ矄 ᆠ� � ᨨ    矄泐矄鼀 ␔├ ᨨ犨F 㦨 Maᆠ鼀 aᆠ鼀㦨 Þ vᆠ鼀㦨ᆠᨨ 矄  和� ᆠ� ��泐vᆠ鼀㦨 \ � ᆠ鼀㦨 㡰 ᔴ ᨨ 鼀矄矄ᨨ 矄ᨨ�  鼀�矄 ᨨ  �盐矄R�矄

R ᨨ ᆠ ᨨ  矄� ᨨ  鼀�矄   R  ´  \ hᆠ鼀 = = =  ᆠ鼀   㡰 s 鼀矄矄  矄�泐ᨨ ᆠ�ᆠ盐 �矄ᆠ 졠��� 鼀矄矄ᨨ   �矄ᆠ m = pa  s  �矄 ᆠ

҈䰘

a s  æ a ö æ p - ҈ö 鼀� � �鼀矄矄 m Ἐ = ç pa  - ÷ s = a  ç s è  ÷ø  è ø Y 鼀ᨨ 鼀矄矄 m =

a  a 

X ҈

犨 ᨨ矄��ᨨ  ᨨ  ᆠ  ᨨ 鼀矄矄

a a ´ m x - mx   X CM =   = m - m a pa   a -a  ⏌  -a -a = = = =  æ p - ҈ ö a   p - ҈㡰 p -  çè ÷ ø \ x =   RA㦨ᨨ鼀ᆠ�ᨨ A RB㦨ᨨ鼀ᆠ�ᨨ B ᨨ ᨨ ᨨ� ⼄盐���盐鼀�  ᨨ� ᨨ ᨨ矄��ᨨ   RB 鼀ᨨ鼀  ᨨ     ᨨᆠ矄 R A x d  x 㡰 ᨨ盐 A ᨨ ᨨ盐 B 矄 ᨨ盐  ᨨ C B \ 㝐ᨨ鼀 ᨨ  ᨨᆠ矄 ᨨ盐 A A pa  ´  -

҈

W 㦨犨�� ᨨ ᨨ 㡰 xW RB = d

xW㦨RBd ᨨ

꾀��  鼀ᨨ鼀  ᨨ  ᨨᆠ矄 ᨨ盐 B,

æ d - xö RA = ç W  ��㡰 è d ÷ø xW æ d - xö \ ᨨ鼀ᆠ�ᨨ ᨨ  A = ç W  ᨨ  B =  è d ÷ø d ҈黨 矄 �矄 ᨨ   ᨨᆠ�矄ᆠ� �ᨨ  犨ᨨ�ᆠ 矄泐矄鼀 和ᨨ ac.m 㦨   ᆠVc.m㦨ᔴᨨ 矄   bᆠ㡰    ᨨᆠ├ ᨨ 鼀矄矄 㝐 鼀ᨨ矄 泐  �矄 ᆠ  ᨨ犨 矄   Mx㦨m Rx㡰 mR Þ x= ᨨ犨 矄   M +m mR \ x= M +m ᔼ �矄 ᨨᆠ�泐ᨨ 鼀矄矄Ἐ鼀Ἐ矄�矄 ᨨᆠ├  �矄   ᨨᆠ�泐 ᨨ  ᨨᆠ├    � 矄     ᆠᆠᨨ � � ᨨ ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 鼀㦨㝐 泐  �泐 ᆠᨨ 矄�ᨨ

҈  ҈  鼀� 㦨 mv + MV   d x㡰W = RAd

ᨨ

m  gR  gR  㦨 m m M ҈+ ҈+ M M ҈  ᆠ㡰 ␔    � � 矄ᨨ 盐   ᆠ泐ᆠ�矄 �  鼀ᨨ�ᨨ    犨 矄鼀ᨨ�   �ᆠ�ᨨ 矄盐ᆠ   ᆠ ᨨ 鼀矄矄 ᨨ  犨 鼀ᨨ ᨨ犨  ᨨ� � �ᆠ�ᨨ 犨�ᆠ�   ᨨᨨ矄� �ᆠ�ᨨ  ᨨ   � 鼀ᨨ�ᨨ  ᨨ    ᆠ  ᨨ 鼀矄矄ᨨ  ᨨ 泐犨� 矄ᆠᨨ�ᨨ盐  ᆠ ᨨ� � �ᆠ�ᨨ 犨�ᆠ� ᆠ├犨  �ᆠ�ᨨ � ᨨ  犨 矄 盐� �  � � 矄� � � �ᆠ�ᨨ  犨� ᆠ �    ᨨ犨 �ᆠ�ᨨ  ᨨ   犨   㡰 �矄 ᨨ  ᨨ⼄盐ᨨ ᨨ 泐ᨨ盐�矄ᆠ ᨨ 鼀矄矄矄ᨨ ᨨ �矄ᆠᨨ 矄  ᨨᨨᆠ�泐ᨨ ᆠ ᨨ 鼀矄矄ᨨ 鼀� ᆠᨨ 矄    ᨨᆠᆠ� � ᨨ  ᨨ 泐鼀盐矄 ᨨ

� 鼀ᨨ鼀 盐鼀ᨨ  �矄ᨨ 矄泐矄鼀鼀� 矄ᆠᨨ 矄   �  �  ᨨ 矄  矄 矄 � �� 矄 ᨨ  �  ᨨ 矄  矄 矄 �  矄 和ᨨ� �犨�㦨

Y R

4m O

LἘ㜠� R

L

m (L,O) (L',O) R

X

L'+�R

␔  矄鼀矄 Mᆠ  �矄�矄ᨨ矄��ᨨ ᨨᨨ  鼀 ᨨ矄��ᨨ    �矄 ᨨ    ᨨᆠ �    ᨨ� ᨨ  �ᆠ�ᨨ   ᨨ  㜠ᆠᨨᨨ � ᨨ ᆠ鼀犨� ᨨᆠ  � ᲼xᆠ鼀桌� ��㦨᲼xᆠ鼀桌 �  M҈ x҈ + M  x M҈ x Ἐ҈ + M  x Ἐ Þ = M҈ + M  M҈ + M 

m ´ L + m ´ � R + L 㡰 m ´ L Ἐ+ m ´ L Ἐ- � R 㡰 = m + m m + m Þ �L졔�R㦨�LἘ�R Þ �L졔҈R㦨�LἘ Þ L졔R㦨LἘ Þ

W

 �㡰

WWW.JEEBOOKS.IN

PS-53

System of Particles and Rotational Motion



꾀矄   � �� 盐 ᆠ  ᨨ  鼀矄矄 ᨨ    犨ᨨ 矄 矄 矄yᆠᨨ㜠ᨨ �  ᨨ� �矄� ��矄 �矄 � 矄矄ᨨ  y㜠ᆠᨨᨨ � ᨨ ᆠ鼀ᨨ  犨ᨨ矄 矄泐矄鼀犨�鼀�  ᨨ  ᆠ ᆠᨨᨨ � ᨨ ᆠ ᨨ 鼀矄矄ᨨ ���矄  L졔R㡰 �㡰  ᨨ 矄 矄 �ᆠ ᨨ �  泐 泐  �矄 ␔ � ᨨ� �   ᨨᆠ ᆠ� � ᨨ    ᨨ   �矄 犨��  

ᨨ鼀 ᆠ�ᨨ  矄 ᨨᆠ矄  �ᆠ ᨨᆠ矄  ᆠ

ᨨ ᆠ  ᨨ� ᨨ  鼀ᨨ�ᨨ   ᆠ   ᆠ  ᨨ 鼀矄矄 鼀ᨨ矄 �ᆠ泐 ᨨ犨 犨 矄 盐矄     ᨨ    ᆠ ᨨ 鼀矄矄 ᨨ  ᨨ �矄 矄�� �  ��㡰 ᔴᨨ 矄�    �泐 ᨨ�  P ᨨ    ᨨ  ᨨᆠ   xy㡰  �矄 ᆠr ᨨ鼀  B ᨨ 鼀├矄

 �q 犨�    ᨨ� ᨨ    �矄 ᨨ矄��ᨨ  y ᔼ DBNP 矄� q =  �㡰 A Y r x + BN x + r ᆠᨨ矄 q ᆠᨨ矄 q = = C L⏌ L⏌ P xy㡰 x y r Þ ᆠᨨ矄 q = q ��㡰 L O N B X -r x    Q  矄� q + ᆠᨨ矄 q = ҈

y

�

m

r

+

㦨 㦨

s p R - s p r  - ҈㡰 ´ 䰘 

㡰 - ҈㡰



=-

҈ ´ ҈ ´ 䰘 = -黨 ᆠ鼀 䰘 ´ 黨

�.e.ᆠ ᨨ 鼀矄矄�矄 �矄 ᆠᨨ 黨ᆠ鼀 ᨨ鼀 ᨨ���

ᨨ犨 矄  

Topic-2 : Angular Displacement, Velocity and Aceleration ҈

dy =  q = Cx dx 꾀P  q = Ca

㡰 y = Cx  Þ

y

w



mw aᆠᨨ矄q N

R r

R r v O 졔Y

ᔴ矄 �㡰

졔X

r

v'

a x

2

ᔴ矄 ��㡰

ᔴ矄 ��㡰 ᆠ ᨨ  鼀矄矄 ᨨ   矄泐矄鼀 �  x㜠ᆠᨨᨨ �  M ´ x + m ´ x = x xἘC㦨 M +m xC㦨xἘC Q   㦨� x㜠 �ᆠ�ᨨ 㡰 mx҈ m R - r 㡰 = \ x㦨 M +m M +m m R - r 㡰 �.e. ᨨᆠ├鼀ᨨ x = 犨 

M +m

 ᆠ泐�  ᆠ 矄   ᨨᨨ鼀 ᨨ�  b ᨨ   ᆠ├ 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀 P�㦨Pf 㦨MVmv MV \ v㦨 m 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ   �泐 ҈  ҈  Þ mg Rr㡰㦨 MV + mv  

MV 桌 m

s ´ p R  㡰 - s ´ p r  ´ 䰘

졔Y x 㦨 Rr㡰

M

᲼Q v =

m Þ mg Rr㡰㦨MV졔 M V m é Mù  ém + M ù mg Rr㡰㦨MV ê҈ + ú = MV ê ú m ë û ë m û g R - r 㡰 m  g R - r 㡰 Þ = V   Þ V㦨m M m + M 㡰 M m + M 㡰  s 鼀矄矄盐 �ᨨ 盐 � ᨨ鼀 \ 㝐矄矄ᨨ  犨 ᨨ �矄ᆠ㦨s맔p R 㝐矄矄ᨨ  ᨨ�ᨨ 鼀ᨨ  㦨 s맔p r R R㦨ᆠ鼀錐r㦨҈ᆠ鼀錐OP㦨䰘ᆠ鼀 ᨨ矄��ᨨ  ᨨ ᆠ  ᨨ  鼀矄矄 r m҈ x҈ - m x x㦨  O P m҈ - m

1

r

M V   

x

=҈  æL ö çè - r ÷ø   ᆠ矄  ᨨ     ᨨ  �矄 ᨨ�  �矄   �矄 ᔴ矄  �㡰 ᆠ  ᨨ 鼀矄矄 ᨨ   矄泐矄鼀 ᨨ 犨ᨨ ᨨ �矄 �

x㜠ᆠᨨᨨ �  M ´  + mx҈ mx҈ = xC 㦨 M +m M +m

\

Þ mg Rr㡰㦨MV졔 m

q P a, b㡰 mg

q

mg矄� q



mw a x

mgᆠᨨ矄q

ᨨ 矄 泐 ᆠ�ᆠ盐 鼀ᨨ�ᨨ

mw a ᆠᨨ矄 q = mg 矄� q



Þw=

g  q a

\w =

g ´ aC =   gC a

ᆠ㡰  rdr w r = rgdh R

h





Þ w ò rdr = g ò dh

w

dh dr

w R  = gh  ෌� R㦨�ᆠ鼀㡰 Þ

\h =

w R  �w = g g

WWW.JEEBOOKS.IN

EBD_8341 PS-54



Physics

ᆠ㡰 ᨨ 泐 ��鼀�   鼀 ᨨ  �矄ᆠ kx





® mw l  + x 㡰 ¬¾¾ m ¾¾

 㦨 �   ᨨᨨ� 

 ᨨ�ᨨ  矄  ᨨ   盐鼀

\ mw l  + x 㡰 = kx

Þ x=



ml  w

k  mw

x mw = k l

b㡰 꾀 ᨨ �  ᨨ矄��ᨨ  x㡰 mv  F � = = mr w r

\ kx = m l + x㡰w Q r = l + x 㡰 ├ 㦨鼀lw졔鼀 w

mlw k  mw b㡰 N矄� q㦨鼀w r⏌㡰 \x=

�

 �㡰

矄� q =

r⏌ ҈ = Þ q = ° r 

 Nᆠᨨ矄q㦨鼀�

w r ᨨ  q㦨 g w r w r ҈ ᨨ   㦨 ᨨ 㦨 g g  g \ 

ᆠ㡰

w㦨

r 

犨�  ᨨ 矄     Q �矄    ᨨ��� �矄ᨨᆠ�泐犨� 泐 ᨨ �턼 矄ᨨ�犨� � 盐 矄    ҈҈

҈



ᨨᆠ㦨

Þ w µ +҈

p w

�鼀�ᨨ   µ ᆠ㡰 ᨨ⼄盐  � q

=

p p



҈

鼀 㡰



+҈ 





 ᨨᆠ�泐 v㡰ᨨ 矄ᨨ 㦨 dx⏌dt    �盐矄  w㡰ᨨ 矄ᨨ�� 㦨 w,a

ᨨ鼀DSOP

x Þ h dx d f = h 矄ᆠ  f ᨨ dt dt v㦨矄ᆠ� 맔҈ v㦨맔맔҈㦨鼀⏌矄

 f㦨 Q Q

\

ᆠ鼀

턼 

+҈ 

l t = Mg 矄� q  꾀矄ᨨ t㦨la l \ l a = Mg 矄� q 

Ml  l a = Mg 矄� q   矄� q la =g Þ  



矄�

 �



҈

�鼀 �ᨨ =

䰘

 ��㡰



鼀w = ᨨᆠ µ Þ w µ

 � ҈ 㦨 㦨 ҈�

鼀 �鼀盐鼀ᨨ�ᨨ  矄 ᨨ   盐鼀� ᨨ盐�ᨨ 矄  鼀� 盐  ҈ ω 鼀㡰 㦨 㦨 䰘  p ҈� T 黨 㡰 꾀t㦨 t =  t = T  �ᨨᆠ�泐犨� ᨨ  T T 꾀t =  t =  �ᨨᆠ�泐犨�鼀 �鼀盐鼀   �  鼀� �盐   ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄 vr 矄盐矄 t �  w ҈ ҈ ᆠ㡰 ᨨ  ᨨ ᨨ�ᨨ ᨨ  �矄ᆠ R  Q p ҈ p O t= ´ =  w w x㜠ᆠᨨᨨ � ᨨ P㦨 wRT P pR > R 矄� �°  = t㦨 

ᨨᆠ  盐 矄   �ᆠ㜠 P  矄ᨨ ᨨ� ᨨ  �> 턼 R矄� �  ; 䰘 졠 盐�矄 ��矄矄矄    ⏌ 矄ᨨ� ω㦨



ᨨk >>mw

Þ

㡰 ᨨ 盐矄 ᆠᨨ鼀 ᨨ�ᨨ

é Ml  ù êQ I rᨨd = ú  û ë  g 矄� q a= l

\ \ \ ҈ 㡰

x㦨h f v㦨 h矄ᆠf㡰w ᲼Q q + f = 黨° 桌

ᨨᆠᨨ  ᨨᆠ├ᨨ �矄ᨨ㦨鼀w㦨鼀㦨鼀  

\

df dt

ò   = ᨨ



ò



 w    Þ  = w  -

 

  =  



WWW.JEEBOOKS.IN

PS-55

System of Particles and Rotational Motion

\



= ò w 

    졠  矄ᨨ� � 犨�

ᨨ

\

=

w  㦨   

  w  - w  졔 =   

w (  + -w ) 

w k㡰

®

� 㦨鼀  Ù ᨨ w 

y 㡰

 �㡰

w é +  -w ùû ë

 O ¬

� = 鼀

\ \

q

 ´  ҈ =  ⏌矄 � ´҈ � m = ҈├� ᨨ犨 盐矄� �  �泐 ᆠᨨ 矄�ᨨ    ᆠᨨ�矄�ᨨ

҈  l I w = mg ҈ - ᆠᨨ矄 q㡰 + mgl ҈ - ᆠᨨ矄 q㡰   ҈ æ �  ö 黨v  Þ ç ml ÷ = mgl ҈ - ᆠᨨ矄 q 㡰 ø �l  è  Þ mv  = mgl ҈ - ᆠᨨ矄 q㡰 �´    䰘 ´ = ҈ - ᆠᨨ矄 q Þ ҈ = ᆠᨨ矄 q ҈  ´ ҈ �  ᨨ ᆠᨨ矄 q = \q ; ° � 㡰 ᨨ⼄盐t ᨨ盐B�矄 ᨨ⼄盐���盐鼀 \ TA ´ ҈ - mg ´ � - mg ´ � = 

Þ TA ´ ҈ = ҈mg

vr

Þ TA = ҈ mg  矄�ᨨ �   矄� �  A㡰

Ù w w  - -w ) w  ( 

TA

Ù 鼀 w w � =  -  -w )  ( 

�ᆠ鼀 �ᆠ鼀

®

®

ᆠ�ᨨ =

TB B

A

Ù Ù 鼀 w w  -  -w ) + 鼀� ⧤ (  

Topic-3 : Torque, Couple and Angular Momentum ҈



 w -w 㦨 㦨 éë w - w ùû  ��㡰   ᨨ鼀 �㡰  ��㡰

\

®

M㦨├�

ᨨ w =

® Ù Ù Ù æ ö æ Ù Ùö ᨨ = � + 鼀 ç ᨨ � ÷ ´ w ├+ 鼀 ç w ├´  � ÷ ´ w ├ è ø è ø Ù ® Ù Ù \ 鼀w � = � + 鼀 ᨨ wæç -  ö÷ + 鼀w  � è ø

盐 㦨

w

� v Þ mvl = ml  w Þ w =  �l

®

҈ b㡰

㡰 矄� � ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀

æ  ml  ö w mvl = ç ml  +  ÷ø è





 +  -







ò

mg mg



F

㡰

ᆠ㡰 꾀 �盐鼀ᨨ鼀 盐鼀 L = I w R Ra 꾀 �矄

l

Mg

m

x

N f

a

ᨨ矄盐 F ´ R ³ Mg ´ x l⏌ 

m

m

l⏌ 

x=

R  - R - a㡰   ᨨ鼀 ��盐

F鼀�

Mg æ R-aö = ´ R  - R - a㡰 = Mg ҈ - ç ÷ R è R ø



æ l ö I = m 㡰  + m ç ´  + m l 㡰  è  ÷ø

�



ᆠ㡰

ml  + ml  = ml   꾀 �盐鼀ᨨ鼀 盐鼀 L = I w = ml  w =

WWW.JEEBOOKS.IN

EBD_8341 PS-56

Physics

꾀ᨨ盐 ᨨ�  졠  �盐 鼀ᨨ鼀 盐鼀 � ��㦨 � 

Þ

mV 

´

҈ é mL mL ù =ê + ú´w  ë ҈  û

V  V = 䰘L 䰘 L b㡰 ෌�   㦨 졔ᆠᨨ矄w1 泐㦨泐졔矄� w2 \w=



=  

泐 = 泐㦨w2ᆠᨨ矄 w2㡰   泐  =  㦨w21ᆠᨨ矄 w1㡰 㦨泐㦨w22矄�  w2㡰   꾀㦨 㦨 졔泐㦨泐 2    㦨w 1 ,泐 㦨 r r r r r ᨨ犨 t =  ´ = 鼀 ´ 㡰 Þ  㦨w1矄�  w1㡰 

䰘

㦨 ᲼  + 㡰 �ˆ+ 泐  ˆ桌 ´ 鼀 -  w҈ ˆ�㡰 = + 鼀泐  w҈ ├ˆ r 㡰 ␔  ��  r = t�ˆ - t  ˆ

r r  t = 㡰 = �ˆ - ҈ ˆ r r dr v = = �ˆ - tˆ ᨨᆠ�泐 dt r v  t = 㡰 = �ˆ - ҈ ˆ r r r L = mvr 矄� qnˆ = m r ´ v 㡰 =  �ˆ - ҈ ˆ 㡰 ´ �ˆ - ҈ ˆ 㡰 = -kˆ



㡰 꾀 �盐 ᆠᆠ�ᨨ  w - w � ´ p -  a= = 㦨҈p  ⏌矄 t � t㦨ᔼa

æ�

ö æ�ö mR  ÷ a  » ç ÷ � ´҈- 㡰 ҈- 㡰҈p èø ø � 㦨맔҈ 鼀 黨 㡰 ҈ ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ 犨ᨨ├㜠 �泐 ᨨ鼀 Þ t㦨 çè 

鼀� 㦨

҈ ҈ 鼀   鼀 꾀  

� 㦨     꾀  맔҈맔҈㦨    �

ÞvB㦨҈�鼀⏌矄 꾀 �盐 鼀ᨨ鼀 盐鼀 ᨨ盐 O LO㦨 mvr 㦨 맔҈맔 LO㦨 ├�鼀⏌矄

r  ˆ ҈҈ 㡰 ෌�  ҈ = -ˆ�㡰 + - 㡰   r ҈ = �ˆ + ˆ

ᨨ⼄盐  盐 ᨨ  ҈ ᨨᆠ æ r r r  ˆ ö ˆ t ҈ = ҈ ´ ҈ = ˆ ´ çç -ˆ�㡰 + - 㡰 ÷÷  =  ├㡰   è ø

ᨨ⼄盐 盐 ᨨ  ᨨᆠ r ˆ ´ ├ˆ =  �ˆ +  - ˆ㡰 t  = �ˆ + 㡰 r r r ˆ t  = t ҈ + t   =  �ˆ +  -ˆ㡰 +  ├㡰 ˆ  = �ˆ - ˆ + ├㡰 r r r ҈ 㡰 ᨨ⼄盐ᨨ盐 ᨨ��� 㦨 t =  ´ 㦨 矄� q Þ �㦨҈맔�矄� q ҈ p 矄� q= � = Þ q=   ҈ 㡰 ᔴᨨ 矄�  矄�ᨨ  �盐矄   �ᆠ├ 矄矄 

ᨨ⼄盐 盐 ᨨ �ᆠ�ᨨ  ᨨ   �矄 矄�  ᨨ⼄盐㦨 å ᨨ⼄盐 ᨨ  � �

ò t =



ò



m  p p 

Ҙ  ·   Ҙ t=  ҈ 㡰 꾀泐� � ᨨ⼄盐 ⼄盐�ᨨ  ᨨ盐 ᨨ�   t 㦨ᔼa㦨᲼㝐 l㡰졔�㝐l桌a Þ �㝐�l 㝐�l㦨᲼㝐 l㡰졔�㝐l桌a Þ t=

Þ 㝐�l 㦨 ҈㝐�l㡰a

� ҈l ҈� 㡰 ෌�      ᨨ  �矄 ᨨ  盐 � ᨨ鼀 鼀矄矄  矄�泐 꾀㦨ᔴ 鼀矄矄ᨨ ᨨ ᨨ  �矄鼀  ᆠ� � ᨨ⼄盐 ᨨ盐 � � ᨨ�  鼀� ᔴ҈㡰㦨鼀� ᔴ㡰 \ a 㦨

æL ö æL ö mg ç 矄� q ÷ = mg ç ᆠᨨ矄 q - L 矄� q ÷ è ø è ø  mgL Þ mgL 矄� q = ᆠᨨ矄 q   矄� q ҈ ҈ Þ 㦨 ᨨ q㦨 ᆠᨨ矄 q   ҈ 㡰 ҈䰘 㡰 ␔├ ᨨ犨 㦨mvr^ 泐

 



 

 꾀

⏌ 



ᔴ  

 









ᔼ  ᨨ  ᨨ    ᆠ矄矄    �ᆠ盐

æ R ö + a÷ �矄 ᆠ ^ �矄 ç è  ø

WWW.JEEBOOKS.IN

PS-57

System of Particles and Rotational Motion ҈

㡰 泐�ᆠ⼄盐���盐鼀

  ᆠᨨ矄

졔矄�  㦨҈�  g Þ㦨 … �㡰  泐 ᨨ� ᨨ  ⼄盐���盐鼀 㦨ᆠᨨ矄

 ҈  N= 㦨  

ᨨ⼄盐 ᨨ盐꾀

 

矄� 

 x

h

l⏌ ҈� 

҈�맔꾀㦨맔 꾀 f  l  g l ´ x \ = x … �㡰 ҈�맔 ᆠᨨ矄 ° =   

h  x ᨨ鼀⼄ �㡰  ��㡰

\ x=

盐ᆠᨨ矄 㦨

҈黨

�

h … ��㡰 ᆠᨨ矄 ° 

l h h   = \  = ᆠᨨ矄 °  l ҈ 㡰 꾀 �盐 鼀ᨨ鼀 盐鼀 L 㦨 鼀 矄�  黨     㦨  맔  맔 ҈ 맔 ҈ 맔 ҈ ᲼꾀矄V 㦨 rw 和�  黨  㦨 ҈桌 和ᨨ L 㦨 ҈ ├�鼀⏌矄

ᨨ 鼀

㡰 ᨨᆠ├�矄� ⼄盐���盐鼀 ᨨ  矄�ᨨ  ⼄盐���盐鼀 SFx㦨 Þ F㦨N SFy㦨 Þ f㦨mg

y

f a

鼀

x

҈鼀

a C

b





b㡰 P ᆠ㡰 ᨨᨨᆠ�ᨨ 矄 ᨨ 鼀    �盐 鼀ᨨ鼀 盐鼀 ᨨ   P mass mᨨ盐O �.e., Lᨨ�矄mrw   �矄 �ᆠ  ᨨ犨  졔 z �ᆠ�ᨨ    �盐 鼀ᨨ鼀 盐鼀ᨨ 鼀矄矄mᨨ盐P l � Lp �矄 mvl   �矄 �ᆠ ᨨ   ��  ᨨᆠ�ᨨ  ᨨ m 矄 矄 ᨨ犨  �    ��盐 ᨨ O v �   ᨨᆠ�ᨨ  ᨨ  m   r �ᆠ�ᨨ  ᨨ  P  鼀� 矄 m r O ᆠ  �� � b㡰 꾀矄�ᆠ�矄ᨨ� �� ᆠ�ᆠ盐  � 矄  �矄 ᆠ矄� � L �矄 ᨨ ᆠᨨ 矄  �  鼀� �盐  和� ᆠ   �ᆠ 矄 犨ᨨ ᆠᆠ�ᨨ 矄 ac   at   ᨨ  

 ᆠᆠ�ᨨ  �矄ur ᨨ ᨨ犨 矄   ᆠ 

 �ᆠ�ᨨ  ᨨ  L  鼀� 矄 矄鼀   犨     矄 ᆠ矄矄

F

N

ᆠ㡰 ᨨ⼄盐犨ᨨ├� �ᨨ  ᨨᨨ 鼀矄矄鼀�矄t㦨mg맔l矄�

q �ᆠ�ᨨ ᨨ ᨨ ᨨ�ᨨ ᨨ �ᆠ㡰

mg

l 鼀

҈

q

ᨨᨨ�ᨨ ⼄盐���盐鼀 Stc㦨

ᨨ⼄盐ᆠ  泐 �ᆠ�ᨨ  ᨨᆠ f 㡰ᨨ盐 C㦨 f맔 a �

ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ 

�矄  ᨨ  ᨨ⼄盐 犨 �ᆠ  矄 ᨨ盐 ᆠᨨ盐   �矄 ᨨ⼄盐

 ᨨ鼀 ᆠ�ᨨ  N ᨨ    ᨨᆠ├ 犨� ᆠ  ᨨ⼄盐 N맔b�   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  和盐ᆠ    f맔a㦨N맔b  ᆠ N 犨� ᨨ 盐ᆠ ᨨ⼄盐

l 鼀�

r 꾀矄 t �矄  �ᆠ盐 ᨨ L   �ᆠ�ᨨ ᨨ L ᆠ  �矄 盐 鼀� �盐  鼀� 矄 矄鼀 ᆠ㡰 ෌� 鼀㦨҈├� q 㦨 㦨҈鼀⏌矄 ® ® 꾀 �盐鼀ᨨ鼀 盐鼀  =  ´ 鼀  㦨鼀ᆠᨨ矄q é  矄�  q ù  矄�  q  = ᆠᨨ矄 q ê ú 㦨 � ûú � ëê

҈2 ´ 矄�  °´ ᆠᨨ矄 °  ´҈ 㦨├�鼀⏌矄  㡰 꾀 �盐鼀ᨨ鼀 盐鼀㦨鼀 맔㡰 æ  ö 㦨  ├� ç ´ ÷ =  ├�   ´ �� -   ˆ㡰 è  ø 㦨├�  ├ˆ 㡰㦨├�맔맔鼀矄҈ ├ˆ 㦨 ├ˆ

䰘



㦨

黨

b㡰 KE㡰ᨨ�ᨨ 㦨

L  I

 L㦨ᆠᨨ 矄  \ KE㡰ᨨ�ᨨ  맔 I 㦨 ᆠᨨ 矄   ᆠ 犨   I �矄 ᨨ盐  KEᨨ�ᨨ  ᆠᨨ鼀矄   㡰   ᨨᆠᆠ� �ᨨ �ᆠ盐 �ᨨ� �盐 � ᨨ鼀 ᆠ�ᆠ盐 鼀ᨨ�ᨨ  �矄 ᆠ � ᨨᆠ ᆠᨨ犨 矄 ᆠ  ᨨ    ᆠ�ᆠ ᨨ⼄盐 盐ᨨ �矄 ᨨᆠᨨ盐 ᆠ �矄 ᨨ ur   ᨨ �盐鼀ᨨ鼀 盐鼀 L ᨨ盐ᆠ �矄ᆠᨨ 矄  㡰 꾀泐� �ᆠ  ��  �盐鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 㦨  �盐�鼀盐矄�� ᨨ 矄泐矄鼀ᨨ盐 ᆠ ᨨ 鼀矄矄 꾀 �盐 鼀ᨨ鼀 盐鼀㡰f   꾀 �盐 鼀ᨨ鼀 盐鼀㡰� L 㦨Mv맔 㦨IC w  �㡰   w �矄   �盐 ᨨᆠ�泐ᨨ  ᨨ  㝐ᨨ鼀  ᨨ ᔼ � ᨨ  矄泐矄鼀 ᨨ盐 �矄  �矄 ᨨ ᨨ�ᨨ

᲼ᆠ  ᨨ  鼀矄矄 ᨨ    矄泐矄鼀桌

WWW.JEEBOOKS.IN

EBD_8341 PS-58

Physics

æ Lö 



æ Lö 



IC㦨 M ç ÷ + M ç ÷ = è ø è ø

ML ML =  

ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀  鼀㡰㦨Iw ҈ 맔�맔黨맔�㦨 맔�맔 �㡰맔w  \w㦨 矄҈ 㡰 ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀 I҈w҈㦨ᔼw

� 㡰

V MVL æ ML ö =ç ÷ w Þ w㦨 L   è ø  b㡰 �矄 ᨨ    ᨨ⼄盐  C  �盐 鼀ᨨ鼀 盐鼀 鼀� 矄 ᆠᨨ 矄 꾀矄 鼀ᨨ鼀  ᨨ  � � � ��泐  犨     ᨨᨨ�矄 鼀ᨨ矄 B ᨨ鼀 꾀 ᨨ   ᆠ矄矄   

� ᆠ矄矄 犨   ᨨᨨ�矄 鼀ᨨ矄 ᨨ鼀  ᨨ ᔴ 矄ᨨ w 犨� � ᆠ矄 A � ��泐    ᆠ矄矄和ᨨ  ��ᨨ ᨨ w�矄 ᨨ �  ҈ b㡰 盐ᨨ� ᆠ矄�  �ᆠ盐 �矄 ᆠᨨ   犨�    �矄 ᨨ ᨨ�ᨨ  MI ᨨ盐   �矄 ᨨ ᨨ�ᨨ  �矄

ᨨ ᆠᨨ 矄  和ᨨ I � ᆠ矄矄

 �矄 ᨨ   ᨨ⼄盐�矄 ᆠ� � dL \t 㦨  Þ L㦨ᆠᨨ 矄  Þ Iw㦨ᆠᨨ 矄  dt 盐 I � ᆠ矄矄 矄ᨨw ᆠ矄矄  ᆠ㡰 ␔    �矄ᆠ ᨨ矄 � 矄 犨ᨨ 泐矄 ᨨ  鼀ᨨ�ᨨ  �  矄�ᨨ    ᨨ�ᨨ   ᨨ    犨ᨨ 泐矄 ᨨ  �盐鼀ᨨ鼀 盐鼀  ᨨ �盐 鼀ᨨ鼀 盐鼀�矄   ᆠᨨ 矄盐鼀 ᨨ  矄 犨ᨨ y ur ur ur L = LT + L R LT㦨 �盐鼀ᨨ鼀 盐鼀 w 盐 ᨨ  矄�ᨨ  鼀ᨨ�ᨨ  R LR㦨 �盐鼀ᨨ鼀 盐鼀 v 盐 ᨨ ᨨ�ᨨ  鼀ᨨ�ᨨ

C ᨨ盐 C.M L㦨MV맔R졔Iᆠ鼀w x O \



҈ 㝐  ´ ω҈ I҈ω҈  \ ω = = ᔼ ì҈   ü í 㝐 + ᲼鼀 桌ý î þ ෌� M㦨�├�R㦨mw҈㦨҈ᨨ ⏌矄 m㦨�├� r㦨m

҈ ´ � ´  ´  ´ ҈ 

=

 㦨 㦨   ⏌ 矄 ҈ ´ � ´  ´  + ᲼ ´ � ´  ´ 桌  졔҈  䰘 㡰   ᆠ  ᨨ 鼀矄矄 ᨨ   � 泐矄矄泐矄鼀    ᨨ��� ἘOἘ�矄 ᆠ犨 AO㦨x OB㦨 dx㡰 졠 꾀  x d㜠x ᆠ鼀 ҈҈Ms Ms ᨨ���

d M s - x㡰 + ҈҈M s d - x 㡰 =  M s + ҈҈M s �d  ᨨ� 泐矄矄泐矄鼀 �盐矄 wᨨ盐 ᆠ  ᨨ 鼀矄矄Ἐ졠Ἐ�矄矄鼀 ᨨᨨ  矄矄

Þ㦨Ms  㡰졔҈҈Ms d x㡰 Þ x =



Iᆠ鼀㦨M.Iᨨ盐ᆠ ᨨ 鼀矄矄C V㦨Rw

҈    㦨M Rw㡰R졔 MR w 㦨 MR w   

\

Y

b㡰 꾀 �盐 鼀ᨨ鼀 盐鼀

ur ur L = r^ ´ p

v

M

w

꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  㝐    y ᆠᨨ 矄   ᆠ �矄  �盐鼀ᨨ鼀 盐鼀犨ᨨ��� 鼀� 矄 ᆠᨨ 矄  ᆠ㡰 和� ᆠ   犨ᨨ ᨨᆠ矄  ᆠ  � 泐ᨨ   � �   ᨨ ᨨ  ᨨ⼄盐�矄ᆠ� �ᨨ  矄泐矄鼀 ᆠ  �盐 鼀ᨨ鼀 盐鼀 鼀� 矄 ᆠᨨ 矄  w1 w2

m 

r

m 



I㦨Mr I㦨Mr 졔mr \ I҈w҈㦨Iw Þ Mr맔w҈㦨 Mr졔mr㡰w (Q w҈ = w ) w㦨

Mw M + m

㦨

㡰

M, L㡰

X

O

\



ædö ҈҈ M s ç ÷ ´ w è ø

y

L㦨Mv맔y





LTᨨtal = LB



æ �d ö ædö  M s ç ÷ w + ҈҈ M s ç ÷ ´ w è ø è ø

m

v

 ᨨᆠᨨ�矄�ᨨ 꾀 ᆠᨨ�矄�ᨨ

矄� �� ᆠ�ᨨ ᆠᨨ 矄�ᨨ ᨨ  �盐鼀ᨨ鼀 盐鼀犨  r r L� = L f Þ mvL = I w

æ ML ö Þ mvL = ç + mL ÷ w è  ø æ 黨 ´ ҈ ö Þ ҈ ´  ´ ҈ = ç + ҈ ´ ҈ ÷ w  è ø

 æ  ҈ö Þ= ç + ÷wÞ= w è ҈ ҈ ø ҈ Þ w =    ⏌矄ᆠ

WWW.JEEBOOKS.IN

PS-59

System of Particles and Rotational Motion 黨

I҈w҈ = I  w 

I҈ = I M



␔ m�矄 鼀矄矄ᨨ 矄ᨨ   w�矄  �盐ᨨᆠ�泐  � 矄  ᨨ �鼀t L 꾀矄ᨨL㦨Iw Þ w = ҈ 盐� � �矄盐ᨨ w�矄⼄ �㡰

黨㡰 M㦨├�m㦨├� 矄� � ᆠᨨ 矄�ᨨ ᨨ  �盐鼀ᨨ鼀 盐鼀L� = Lf

M

æ M R ö + I m 㡰 = ç  + mR  ÷ ç  ÷ è ø

m

҈ I  = M  R    w҈ = � 鼀  æ M R ö � \w = çç  + mR  ÷÷ ´  è  ø M R   �R  + ҈㡰 = 黨 鼀 =  ´ ҈ R � ᆠ鼀㡰 

҈

鼀�

dx dx = - Aw 矄� wt  Þ = - Aw  ᆠᨨ矄 wt  dt dt \㝐� �盐 ᨨ  鼀 �鼀盐鼀ᆠᆠ�ᨨ ᨨ   ᨨ鼀 \ 㝐 ᆠᆠ�ᨨ 㦨Aw ␔    ᨨ鼀 鼀ᨨ矄  ᨨ⼄盐 ᆠ矄 ᨨ    ᆠ泐�      ᆠ泐�   ᨨ矄 ᨨ盐 �矄  �矄 f 꾀ᆠᆠ�ᨨ  ᨨ ᆠ泐�  a҈ = m

ᨨ⼄盐 t 㦨 f R 㦨 Ia fR fR = Þ a = I MR  ⏌ 

҈ᆠ鼀

ᔼ ��泐

 㝐� 㝐� = 黨 黨

ᨨ⼄盐ᨨ盐 ᆠ tᆠ  㦨  � �㝐� \ ҈ �㡰㦨 㡰  = 㝐� = 黨 黨 �㦨 졔 㦨㝐�

 =

҈ 㦨 m⧤

҈ 㦨m和

҈ 㦨

҈ 㦨





f f ᨨ Ra 㦨  㦨a㡰 MR M \  ᨨᨨ鼀 � ᆠᆠ�ᨨ  f f f + = a鼀 㦨 a҈ + a 㦨 M M M  f MAw ᨨ Aw  㦨  Þ f㦨 M 

盐矄鼀 �鼀盐鼀ᨨ⼄盐







⧤ 㦨  Þ 㦨  ҈ 㦨�     = 㡰 Þ   =  � ᨨ犨 㦨 �矄 ᆠ犨  ��  � �矄ᨨ矄   � � 矄矄 鼀ᨨ� � ᲼ ᨨ⼄盐 ᨨ盐 ᆠ  ᆠ  㦨 桌  㦨 㡰   㦨 ⧤ Þ 㦨  ҈ 㦨   㡰 =   �

҈

҈ = � ᆠ鼀 �

mv  㦨mrw r



MAw  R ҈  㦨 MARw    �矄 ᨨ   ᨨᆠ   ᆠ ᨨᨨ⼄盐�矄�     �盐 鼀ᨨ鼀 盐鼀 鼀� 矄 ᆠᨨ 矄  �.e.錐 l҈㦨 l \ I҈w҈㦨Iw ML ´ w M w Iw ҈ \ w㦨 ҈ ҈ = 㦨   M + m I ML æ Lö + m ´ ç ÷ è ø ҈  矄 ur I҈w҈㦨Iw Q L = ᆠᨨ 矄  㡰 t鼀 㦨

f맔R㦨

҈  I҈㦨 MR 

҈ ҈ M  æ  + ҈ö � MR  + R =ç MR  = MR  ÷ è  ø     w҈㦨w ; w㦨䁸 ҈ MR  ´ w I҈w҈    =+ = w= w w㦨 � I ´� � MR  

I㦨

   泐� 矄  ᨨ  �鼀 t    �盐矄 ᨨ    ᨨ� ᨨ  矄盐 ᆠ㦨r T㦨

a

ᨨ

 㦨  㦨  ⧤ ᔼ 㦨 �矄 ᆠᨨ   � � ᨨ鼀ᆠ 犨  ��  � � 矄矄 鼀ᨨ� � t 㦨㡰ᨨ盐ᆠ Þ  㦨 㡰

\ =

m

æ L ö = ´ r Þ T = ç ÷ r - è mø mr  㡰  mL

Þ



黨ᆠ鼀

T

æ L ö = A ᆠᨨ 矄  ÷ çè ø m  ᔴᨨ 矄� � �   鼀ᨨ�ᨨ  ᨨ    ᨨ鼀 x㦨Aᆠᨨ矄wt �� 㡰

ᆠ鼀

�

I

r

ᨨ  = Ar - \n 㦨





T㦨

mrL

w

 �㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-60

�

Physics

ᆠ 㡰 ᨨ鼀  �盐 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ  ᨨ盐  �ᨨ  ᨨ� 

䰘

꾀泐� � F =

�ᨨ ᨨ� 

æ 鼀 ö 鼀 = ç + 鼀  ÷ w ç  ÷ è ø

bᆠ㡰෌� ᨨ � �泐 㡰㦨⧤⏌

ᨨr㦨RF㦨kR



dv d é kr  ù = ê ú = kr dr dr êë  ûú

mv   Q �ᆠ�矄鼀ᨨ� �� ᆠ�ᆠ盐ᨨ�㡰 R mv  k = kR Þ v = ´R ᨨ R m

꾀矄ᨨ F =

᲼꾀矄   ᆠᨨ鼀�   矄泐矄鼀 ᨨ矄 犨�   �盐 矄 w ᨨ盐   �ᨨ桌 鼀  鼀  \w = =  鼀  +    + 鼀   w=   +    ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ w = ᨨ鼀 �鼀盐鼀 �盐ᨨᆠ�泐

盐

æ k ö R÷ R = kmR ÷ m è ø

꾀  �盐 鼀ᨨ鼀 盐鼀 L = mvR = mçç 

ᆠ㡰 ᔼ   ᨨᆠ 㡰�矄 �   � �    t 鼀� 矄ᆠᨨ 矄   t 㦨 맔  ᔼ  ᨨᆠ�矄�  ᨨ鼀ᨨ  矄 犨 矄ᆠ�鼀矄       �ᆠ盐 �矄 ᆠ ᨨ  ᨨᆠ ᨨ鼀 턼 犨� �ᨨ ᨨ  ᆠ  �� � � ��泐    �ᆠ盐 �矄 턼㝐  � ᆠᨨ鼀矄 턼㝐Ἐ

ö æ  ç +  ÷ =  ÷ çè ø

Þ

 x





 

+ = Þ x =

㝐¢



  和ᨨ ᨨ�ᨨ  ᆠ㡰 �矄 ᆠᨨᆠ



\ 鼀 =

w鼀 =



 



  +  

=



=



  

æ  ö  +  ç ÷ è ø  ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ ur r ᆠ㡰 ෌�  F = at�ˆ + bˆ ᨨ F = t�ˆ + ˆ r md v \ = t �ˆ + ˆ dt r \ dv = t dt �ˆ + dt ˆ \

v

r

黨

Q a = 1NS -҈  b = 1N 㡰

ᔼ   ᨨᆠ 㡰 �矄 �  ᨨ鼀 ᨨ   ᆠ�ᆠ盐鼀  ᆠ  ᨨ�     t �矄 ᨨ ᔼ   ᨨᆠ 㡰�矄�  � �泐ᨨ� 和 

t = F ´ R   犨 ᆠ�鼀矄 ᆠ 㡰 ᨨᆠᆠ� �ᨨ ᆠᨨ鼀 㦨\ 㦨  ᨨ  ᨨᆠ ᆠ� �� �ᆠ �ᆠ�ᨨ 犨�鼀ᨨ 鼀� ᨨ� ᨨᆠᨨ鼀 ᨨ     �ᆠ泐 ᨨ犨 犨 矄 Ӹ 㡰



᲼Q m = ҈桌

t

t

ò dv = ò t dt �ˆ + ò dt ˆ

黨q

r t v = �ˆ + tˆ  ҈ r ҈ -҈ 꾀 t = ҈s v = �ˆ + ˆ = �ˆ +  ˆ 㡰鼀矄   r   r dr t ˆ ˆ = � + t \  drr = t dt �ˆ + t dt ˆ 꾀矄ᨨ v 㦨 dt   ᨨ

r

r





t t

t

r

t

t

ò d r = ò  dt �ˆ + ò t dt ˆ \  r =  �ˆ +  ˆ

r ҈ ҈ 꾀 t = ҈ r = �ˆ + ˆ  

r \ r =

r r r æ҈ˆ ҈ t=r ´F =ç � + è 

r ҈ ᨨ t = - kˆ 

\

҈ ҈ ҈ + =   

ˆ ö÷ ´ �ˆ + ˆ 㡰  t㦨҈矄㡰 ø

r ҈ t = 鼀 

泐㡰 

q

⏌



L 矄� q 

q

⏌ 鼀�

L ᆠᨨ矄 q 



␔   鼀├矄   �q  �� ᨨ �矄 ᆠᨨ鼀 L 㦨 ᆠᨨ矄 q  \ �矄ᆠ鼀 ᨨ �矄鼀� ᨨ�  ᨨ鼀 � ��ᨨ矄��ᨨ

L L L - ᆠᨨ矄 q 㦨 ҈ - ᆠᨨ矄 q㡰    ᔼ 矄  ᨨ盐矄 ᨨ⼄盐 ᨨ盐   ᨨ�  ᨨ  ᆠᨨ ᆠ  L t = mg ´ 矄� q 

WWW.JEEBOOKS.IN

PS-61

System of Particles and Rotational Motion ᨨ犨 x =

�

é ma m a㡰  ù ҈䰘  LCM = I CM w = ê + ma w úw =    ëê ûú 㝐� �盐 ᨨ  �盐鼀ᨨ鼀 盐鼀 ᨨ ᔴ㝐 ᨨ 矄泐矄鼀ᨨ盐 ᨨ� O.

L 矄� q  y = L 矄� 黨° - q㡰 = L ᆠᨨ矄 q 

  x y æ x ö æ y ö \ç ÷ + ç ÷ = ҈ ᨨ  +  = ҈ è L ø è Lø L L

盐矄 ᨨ 꾀�矄  �矄 ᨨᨨ b㡰 r ෌�  r = at �ˆ + bt  ˆ

黨w 黨 ҈鼀w ҈ 鼀w  ´ = = � � � � 㝐� �盐  ᨨ  㜠ᆠᨨ鼀ᨨ   ᨨ   �盐 鼀ᨨ鼀 盐鼀 ᨨ 矄泐矄鼀 ᨨ盐 ᨨ�   Lz = L'ᆠᨨ矄q  Lᔴ㝐 矄� q ¢ = �鼀 ´

r ҈ r = t �ˆ + �t  ˆm  r r dr = ҈t  �ˆ + ҈tˆ ms ҈ \ v= dt r r dv a = = t�ˆ + ҈ ˆms -   dt r ҈ 꾀=҈矄 rt =҈ = �ˆ + � ˆm 錐  r r - vt =҈ = ҈�ˆ + ҈ ˆ ms ҈   at =҈ = �ˆ + ҈ ˆ ms r pt =҈ = �ˆ + ˆ kgms ҈ ˆ kˆ �ˆ r r r L = r ´ p = ҈ �  = kˆ é ҈ - �ù = - � kˆ ├�鼀矄 -҈ êë  úû  

҈ mwa  ҈䰘  ҈ ´ - ma w ´ � � � � ҈黨 ҈䰘 æ ö = ma w ç è � ҈ ÷ø � 㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀盐鼀 盐鼀 ᨨ盐   �矄 =

MR맔w㦨MR맔 和ᨨ� � 犨 � Þ �

҈ ҈  r r F = ma = �ˆ + ˆ 㡰 N ˆ kˆ �ˆ

�҈

P

Þ �

l

ᆠᨨ矄 q =

a

q

O

w

l l �

҈ l +a



=

 a 

a +  a



=

 �

éQ l = ë

a �� ùû

OA㦨 l 㡰 + a㡰 = 黨a  + a  = ҈a  ᆠᨨ鼀 矄泐矄鼀 ᨨ矄 ᨨ盐 z㜠 �矄 犨�   ᆠᨨ 矄   �盐 ᨨᆠ�泐 w¢

w' p a㡰 w = Þ w' = � w p ҈a㡰 㝐� �盐  ᨨ  �盐 鼀ᨨ鼀 盐鼀 ᨨ   矄泐矄鼀 ᨨ盐 �矄 ᆠ  ᨨ  鼀矄矄

\

㡰 ෌� 

r

A 

҈  q =

å

f҈㦨 m҈҈





f㦨 m

鼀�  r Fext =  r d p矄泐矄鼀

r 㦨 Þ  p矄泐矄鼀 㦨ᆠᨨ 矄  dt � �  鼀ᨨ鼀 盐鼀 ᨨ   矄泐矄鼀 ᨨ矄 ᨨ ᆠ  � �

�鼀 盐ᨨ�   ᨨᆠ矄ᆠ� ��  矄泐矄鼀 ├� �ᆠ ᨨ �  �泐鼀泐ᆠ  � 犨�  �鼀 꾀矄ᨨ ᨨ    ᨨᆠ 鼀泐 ᆠ  ᨨ⼄盐 盐矄   ᨨ⼄盐犨�ᆠ  �  �盐鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀�

�鼀 �� bᆠ㡰 ur uur æ r dL ö r ur ur dL ur ur = A´ L ෌�  t = A ´ L Þ çQ t = dt ÷ è ø dt uur dL ᨨ鼀 ᆠᨨ矄矄㜠ᨨ 盐ᆠ 盐  �矄  �ᆠ盐 ᨨ ᨨ dt ur ur A   L r ur ᨨ鼀 ᨨᨨ 盐ᆠ盐 L  L = L �  �� � 犨�  矄ᆠ ᨨ �鼀

å Fext =

a

黨a �

ᆠ 㡰␔  m҈¹ m¹ ᨨ� ᨨ ⼄盐���盐鼀҈㦨m �ᆠ⼄盐���盐鼀鼀�㦨졔m1҈ 和ᨨ� �   ᨨ ⼄盐�ᨨ 矄 犨 �

l 鼀� ´ ᆠᨨ矄 q = ҈ ´ l 矄� q 

m m

R �

鼀� N  m mg ҈ + m҈m q  ␔  m҈㦨 錐 ᨨ⼄盐ᨨ盐

m 㡰 + m l 㡰 l = m + m �

w'

㦨

 =

r r r ҈ é҈ ù - ˆ t=r ´F = �  = kˆ ê - ҈ú = k 鼀   ë û  ҈  ᆠ㡰ᨨ矄��ᨨ ᨨ ᔴ㝐 ᨨ   �矄ᨨ ᨨ  xᔴ㝐 =

w M 黨 R  w M  w 졔 맔 맔 졔 r 맔 黨  黨 黨  �

WWW.JEEBOOKS.IN

EBD_8341 PS-62

Physics

uur uur uur ur dL ur dL ur dL dL dL = L L× + L× = L  Þ L × dt dt dt dt dt ur dL L^ 和� ᆠ dt uur r dL dL = \ L × =   Þ  dt dt Þ L 㦨 ᆠᨨ 矄 

盐矄 r   鼀� �盐  ᨨ L 犨泐矄 鼀� 矄 ᆠᨨ 矄  꾀矄 A  �矄  ᆠᨨ 矄  ᆠᨨ   � �矄 犨泐矄  �ᆠ盐 r ᨨ t r r 꾀矄ᨨ L �矄  �ᆠ盐ᨨ A r r rr Q  L ^ A \  L A =  r  ᆠ � ᆠ   ᆠᨨ ᆠ盐     ᆠᨨ鼀ᨨ   ᨨ  L  ᨨ � r A �矄 ᨨ�ᆠᨨ 矄  � b 㡰꾀 �盐鼀ᨨ鼀 盐鼀 L = r ^ ´ P 꾀 �盐 鼀ᨨ鼀 盐鼀 ᨨ盐 ᨨ�  O mv ´h L㦨  �㡰  vᆠᨨ矄� h

v

꾀 �盐鼀ᨨ鼀 盐鼀L㦨m᲼Vy x  Vx y桌 ᨨ

 év æv v ö v ù ö æ v  ´ ç  - v ÷ - ç  -  ÷  ú L㦨m ê ø è  g g ø  ú êë  g è  û

é v v v v ù -  -  +  ú L㦨m ê  g  g   g ûú ëê  g - mv mv é ҈ ҈ ù 㦨 ú g êë   û   g ur r ur 꾀��  L = r ´ p  ᆠ   �ᆠ�ᨨ ᨨ L �矄  �ᆠ盐 ᨨ  ᨨ 鼀ᨨ�ᨨ   �矄 �ᆠ 犨泐 ᨨ鼀   L㦨

Topic-4 : Moment of Inertia and Rotational K.E. ҈

㡰 ᨨᨨ犨�ᆠ㜠ᆠ鼀ᆠᨨ ᆠ 矄矄盐鼀矄矄矄 ᨨ  �矄ᆠ矄 � � �    �盐矄 矄ᨨ

I = ò dI = ò dm r  㡰

 �㡰

R

v Ö

h

�

r

H

O

꾀矄ᨨh㦨

v  矄�  q v  = g g

᲼Q q = �°桌

q

 ��㡰

ᨨ鼀⼄ �㡰  ��㡰 L㦨

m 

ᨨ鼀 ��鼀

 gh 㡰 h = m gh

r R R =  q = ᨨ r = h h H H

v mv  ´ = 꾀矄ᨨ L㦨  g   g mv

�䰘

㝐矄矄 ᨨ 鼀  dm = r pr  㡰dh ᨨ鼀⼄ �㡰 ��㡰  ���㡰

v  꾀  �鼀 t 㦨  x y㡰    ᆠᨨᨨ � 矄 ᨨ   

꾀ᨨ 鼀  dA = prdl = pr

g �ᆠ  vxvy ᆠᨨ鼀ᨨ  矄ᨨ ᨨᆠ��矄   �鼀  ᨨᆠ�泐�  ᨨ� ᨨ  �ᆠ�ᨨ

v

o

vx㦨 v ᆠᨨ矄 � =



 Ö

v

I = ò dI =

v

x

Ö

꾀泐� �v㦨u졔�  �ᆠ �ᆠ�ᨨ

H

H

H





æR ö   ò dm r 㡰 = ò r pr 㡰dh çè H × h÷ø

æ æR

 ö ö ÷ dh ø

 =

v v ´  =  ᔼ  ᨨ� ᨨ  �ᆠ�ᨨ  x = vx ´ t 㦨  g g ҈ 2 ᔼ �ᆠ �ᆠ�ᨨ 泐� �S㦨ut졔 at 

和ᨨ� �犨� I =

)



v

v v v ҈ v ´ - g  =  -  y㦨  g  g g  g v





ò r çè p çè H × h÷ø

æv ö v v y = v 矄� �o - g ç  ÷ 㦨 v - g ´ v 㦨  - v è gø g  

(

dh ᆠᨨ矄 q

R R  + H  ᆠᨨ矄 q

 r = h  q 㡰



 ���㡰

 Mh  dh

㝐矄矄 ᨨ 鼀  dm =



�

 ��㡰

MR   dm

b㡰 A

B x

dx 㝐矄矄 ᨨ  矄鼀鼀 ᨨ  ᨨ

WWW.JEEBOOKS.IN

PS-63

System of Particles and Rotational Motion

y

dm = l × dx 㝐ᨨ鼀 ᨨ � �ᨨ 矄鼀鼀  xö æ dI = dm × x  = l  ç҈ + ÷ × x  dx è Lø 㝐ᨨ鼀 ᨨ � �ᨨ  ᆠᨨ鼀ᨨ ᆠ  ᨨ�  泐 � ��ᨨ

҈  ᆠ鼀

O

 = l 

 L

䰘l  L ҈ 㝐矄矄 ᨨ    �  ᨨ  ÞI =

L

L





æ M = ò l dx = ò l  ç҈ + è



IO Ἐ = IO + M �㡰

éL L x x + = l ê + ú  L  û ë 

ù

 �㡰 

l  L xö ÷ø dx = L 

M \ l = L 䰘 æ M ö  䰘 ML \I = ç ÷L ÞI = ҈ è L ø ҈ 㡰 泐 �盐 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ  Lc = L f w wI +  I ´  =  I w Ἐ Þ w Ἐ =  ҈  w KE 㡰� = I w  ҈ KE 㡰 f = I + I 㡰w Ἐ 

DKE =



dx

OἘ dmR dI = + dmx   n= - L ⏌  dmR  M Þ I = ò dI = ò + ò dx ´ x   L n= L ⏌  

I I

҈  ҈    Iw - Iw = Iw   

  Iw  DKE  = =  \ ᆠ�ᨨ ᨨ矄矄� ⧤쟼 = ҈   KEl� Iw  ᆠ㡰 p    矄�泐ᨨ   �矄ᆠ矄 t�矄  �ᆠ├ 矄矄 ᨨ  �矄ᆠ矄 㝐ᨨ鼀  ᨨ  � � ᨨ  �矄ᆠ �矄 ��  泐

MR  ᲼r pR  㡰t 桌R  =   꾀矄r t矄鼀㡰 I µ R

I=

�

I  æ R ö ҈ = Þ = a Þ a =  I҈ çè R҈ ÷ø ҈ b㡰 㝐ᨨ鼀  ᨨ � � ᨨ  ᆠ �盐 矄  ᨨ盐    �矄 矄矄� �  ᨨ盐�  O M  M a + b  㡰 = ᲼ 㡰  + 㡰 桌 IO = ҈ ҈

MR  ML +  ҈ M V ML MV ML ÞI = ´ + ÞI= +  pL ҈ pL ҈ dI mV M ´ L =+ =  ҈ dL pL   Þ V = pL Þ pR  L = pL    L \ =  R b㡰 ᔼ �� �盐鼀ᨨ鼀 盐鼀 = I҈w҈ + I  w   w   �盐 矄  ᨨ   ᆠᨨ鼀�   矄泐矄鼀 �  �盐鼀ᨨ鼀 盐鼀 = I҈w + I  w 꾀ᆠᆠᨨ � � ᨨ ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀 I҈ + I  㡰w = I҈w҈ + I  w  ෌�  I =

I w ҈ æ wö ´  I 㡰 ´ ç ÷ = è ø  



M  +  㡰 IO ҈ ҈ = = M IO Ἐ   +  㡰 + M �㡰  ҈ ᆠ㡰  ᆠ泐� ᨨ 鼀矄矄 m � L  �盐矄 Rᨨ犨├鼀 泐 �矄ᆠᨨ  �盐矄R  �ᆠ├ 矄矄dx   �矄 ᆠᨨ  x ᨨ鼀  �矄 OOἘ    鼀ᨨ鼀  ᨨ  � � ᨨ盐OOἘ ᨨ  �矄 鼀  O

R



 =

ᆠ鼀

x ᆠ鼀 ᨨ鼀  �矄 ᨨ鼀鼀ᨨ鼀 ᨨ � �ᨨ盐O Ἐ

æ x ö I = l  ò ç x  + ÷ dx Lø è L



O'

䰘

I҈w҈ + I  w  ҈ ´ ҈ +  ´ �  = = I҈ + I  ҈ +   �  ᨨ�ᨨ  ├� �ᆠ �泐 Þw=

҈ ҈ ҈ æ  ö I҈w  + I  w  = ҈ + 㡰 ´ ç ÷ è ø     Þ Kf =  



Kf =

WWW.JEEBOOKS.IN

EBD_8341 PS-64



Physics

㡰 㝐ᨨ鼀 ᨨ � � 

 æd ö  m ç ÷ + m ( AO ) � èø d   AO = 

I҈ =

㝐ᨨ鼀  ᨨ � � ᨨ盐 �졠  é  æ d ö æ d ö ù I  = I҈ =  ê m ç ÷ + m ç ÷ ú êë � è  ø è  ø úû

҈ Md  ҈ é  æ d ö ù  æ d ö 꾀  I A =  ê M ç ÷ + Md  ú + M ç ÷ êë � è  ø úû � è  ø  Md  Þ IA = ҈ ҈ Md  IO ҈ ҈ \ = =   IA Md  ҈ 㡰 矄� � � ᆠ� ᨨ  ᆠᨨ 矄�ᨨ  ᨨ   �泐 Þ I =

黨

҈ ҈ m҈ + m 㡰v  + I w   ҈ ҈ m҈  m 㡰 gh = m҈ + m 㡰 wR 㡰 + I w   Q v = wR 㡰

m҈  m 㡰 gh = Þ

Þ

w é m҈ + m 㡰 R  + I ù û  ë  m҈  m 㡰 gh

m҈  m 㡰 gh =

Þ w=

m҈ + m 㡰 R  + I

҈ 㡰 ␔     ᨨ ᆠᨨ   �矄 ᆠ � 

҈  ҈  mv + I w    ҈ ҈ mr = 鼀 w 㡰 + ´ ´ w Q v = wr nᨨ sl�pp�ng 㡰       Þ mgh = mw r   gh ҈  gh Þw= =  r  r ҈҈ ᆠ㡰 㝐ᨨ鼀  � � ᨨ    ᨨ  矄矄� �  ᨨ盐�   ᨨ�  l 犨泐 ᨨ鼀   ᆠ  ᨨ    ᨨ  I=Ig졔鼀l æ I  ö 䰘 MI  MI  Þ I= + M ´ç ÷ = ç ҈ ÷ ҈  è ø 矄� � mgh =

䰘MI  矄� � I = MK =  K㦨 �盐矄ᨨ �泐�ᨨ 㡰  

Þ K=

䰘 I 

҈ 㡰 ෌�  鼀矄矄盐 �ᨨ ᆠ�ᆠ盐 �矄ᆠs㦨A졔Br 꾀ᨨ  � �㦨pdr 㝐矄矄ᨨ  � �dm㦨sprdr 㝐ᨨ鼀 ᨨ � �

I = ò dmr  = ò s prdrr  a é Aa  Ba� ù Þ I =  p ò A + Br 㡰r  dr = p ê + ú � úû êë   é A Ba ù Þ I = pa  ê + ú ë � û b

҈ ᆠ㡰 I㦨 ò dm㡰r



a b

æ s ö   ps  b  r a 㦨 ò ç r ´ pr dr ÷ r 㦨 ø  aè

ps  b - a  㡰  㝐矄矄 ᨨ   �矄ᆠ 㦨

b

s m㦨 ò r ´ pr dr 㦨ps ba㡰 a

 �盐矄 ᨨ  �泐�ᨨ  k㦨

I m

ps ⏌ 㡰 b - a 㡰 a  + b + ab 㦨 㦨 ps b - a 㡰  ҈ 㡰 꾀矄 ᨨ   ᨨ⼄盐�矄ᆠ� � 矄ᨨ �盐鼀ᨨ鼀 盐鼀 矄 ᨨ盐   ᆠᨨ 矄 ᔼ҈졔ᔼ㡰w㦨ᔼ҈w҈졔ᔼw᲼wᆠ㦨ᆠᨨ鼀鼀ᨨ  �盐ᨨᆠ�泐ᨨ   矄泐矄鼀 犨   �矄ᆠ矄  �  ᆠᨨ ᆠ桌 ᔼw ᔼ҈w҈ + ҈ ҈  æ � ´  öw wᆠ = ç ÷ ҈ ᔼ  ø ᔼ҈ + ҈ è  �w҈ wᆠ =  ҈ ҈ ҈ 쟼 - 쟼� = ( ᔼ҈ + ᔼ ) wᆠ - ᔼ҈w҈ - ᔼ w    �w҈ 盐ᔼ㦨ᔼ҈⏌ wᆠ㦨 �w҈⏌  ␔ �  ᔼ w 쟼  쟼� =  ҈ ҈  ҈� b㡰 꾀矄 ᨨ鼀  ⼄盐矄�ᨨ   矄�泐 s㡰㦨 ├

㝐矄矄ᨨ  �矄ᆠ 㝐 =

ò ├ 

Þ├=



㡰 p  =  p├

 p├  =  

㝐

p  \㝐ᨨ鼀 ᨨ � � ᨨ盐  �矄 ᨨ   �矄ᆠ

 �㡰

WWW.JEEBOOKS.IN

PS-65

System of Particles and Rotational Motion

 = ò  = ò ( 鼀 )   = ò s 꾀  = ò ├ 㡰 p 㡰 

=



æ 㝐 ö p´ ç ´   ÷ p ├  è p ø = ò p├ �  = = = 㝐      ᲼盐� �盐ᨨ ├ ᨨ鼀⼄  �㡰桌 ҈ b㡰

 é  ù pr R  ú R  = MR  � êë  � û



b㡰

҈

㡰 꾀ᆠᆠᨨ � � ᨨ   矄  ᨨ鼀

ᔼ= 

 鼀  + 鼀  �

 ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄 ᔼ矄  㡰 鼀矄矄ᨨ  �� �㦨㝐 和� ᨨ �� �㦨l 㝐ᨨ鼀 ᨨ � �ᨨ �� �㦨鼀

㝐 㝐矄矄ᨨ 矄鼀� �㦨   � ᨨ 矄鼀� �㦨

҈ æ 䰘M ö ö ҈ æ 䰘 I҈ = ç = ç ´  ÷ MR  = 鼀  ÷  R㡰  è ҈ ø  è  ø ö æ MR  æ M ö R æM ö  Þ = = I ç ÷ I = ç ÷ r  ç ÷ � è  ø çè  ÷ø  �è  ø ҈  ù é  ê  pr r =   pR ´ r ú ê ú ëêÞ r = R ⏌ ûú I҈ ҈ ´  = = ҈ I 

㝐ᨨ鼀 ᨨ � �ᨨ 鼀ᨨ � �㦨 

㝐 æö ç ÷ ᔼ  \ 鼀ᨨ =   è ø 㝐 㡰 ᔼᨨ���  ᔼ ᔼ 鼀ᨨ =  ҈



æ M w ö \w f = ç ÷ è M + m ø ҈黨 ᆠ㡰 ├� �ᆠ�ᆠ盐� �ᨨ  �盐矄r  �ᆠ├ 矄矄dr矄 鼀矄矄 鼀  矄ᨨᨨ 鼀矄矄 R

M = ò r r ´ prdr = 

R

pr R  

IC = ò r r ´ prdr ´ r  = 

㦨 a

ᨨ鼀 犨ᨨ 矄 矄ᆠᨨ  犨 졔 㦨鼀 a㡰

├� � ᨨ⼄盐ᨨ盐  犨 � 맔  맔 㦨ᔼa 맔  맔 㦨鼀 a  㦨鼀 a 和ᨨ� �⼄盐�ᨨ  �㡰  ��㡰  a= = ҈ ⏌ 矄  鼀 



pr R � �

矄� � �矄 ᨨ鼀 � æ ҈ ҈ ö ҈ pr R \ I = I C + MR  = pr R � ç + ÷ = ҈� è �ø







 æ ML ö æ Lö ö + m ç ÷ ÷ w f ÷ w = ç ÷ ç ҈ è  ø ÷ø ø è

㝐æö  çè  ÷ø

ᔼ ҈�ᔼ 和ᨨᔼ㦨ᔼ -  = ҈ ҈ b㡰



҈  I w = kQ   æ k ö ᨨ w = çç ÷÷ Q è I ø dw  K æ dQ ö æ k ö = ᨨ a = ÷w ç ÷=ç p I è dt ø çè I ÷ø æ k öæ k ö =ç q k q ÷ç ç I ÷ç ÷÷ = I I è øè ø ҈ ᆠ㡰 I�w�㦨Ifwf ҈䰘 㡰

æ ML ᨨ çç ҈ è

l 

 �㡰

 ��㡰

b㡰 㝐ᨨ鼀 ᨨ � �ᨨ  �矄ᆠ҈ᨨ盐졠졠¢㦨ᔼ҈㦨

㝐  

㝐졠ᔼᨨ ᨨ盐졠졠¢

҈ æ 㝐  ö 㝐   + 㝐  ÷ + 㝐 = 㦨ᔼ㦨 ç è  ø  㝐졠ᔼᨨ ᨨ盐졠졠¢ ҈ æ 㝐  ö 㝐   + 㝐  ÷ + 㝐 = 㦨ᔼ㦨 ç è  ø  矄ᨨ矄盐 㝐졠ᔼᨨ盐졠졠¢�矄ᔼ㦨ᔼ҈졔ᔼ졔ᔼ Þᔼ =

æ 㝐  ö 㝐  + ç + 㝐  ÷  è  ø

 =

㝐  㝐   + + 㝐  㦨㝐  

WWW.JEEBOOKS.IN

EBD_8341 PS-66

Physics

 ᨨ 鼀矄矄 ᨨ   �矄ᆠ 㦨s맔pR㦨黨M

鼀矄矄 ᨨ  ᆠ�ᆠ盐 �矄ᆠᆠ盐

├ � ᆠ㡰 꾀矄犨├ ᨨ犨 w = ᔼ

w=

é êëQ ᔼ

├ 鼀l



ᨨ =

҈ ù 鼀l ú  û

 矄�ᨨ  犨   � 矄矄矄  ᨨ盐�    鼀  ᨨ矄��ᨨ 

= 鼀w q 

 l ├ l = 鼀  q = ├q   鼀l l

҈ æ Rö 㦨 ´ M ´ ç ÷ è ø 

  é҈ æ Rö æ R ö ù ú 㦨 ê ´ M ´ ç ÷ + M ´ ç ÷ è ø è  ø ú êë  û ᲼矄� �  �ᆠ盐  �矄  ᨨ鼀桌 \ ᨨMIᨨ  矄泐矄鼀ᨨ盐  �矄矄矄� � ᨨ盐� O  �ᆠ盐ᨨ   ᨨ   �矄ᆠ�矄 I㦨I҈졔I

ᔼ ��ᨨ矄��ᨨ





  é҈ ҈ æ Rö æ R ö ù  㦨 黨MR - ê ´ M ´ ç ÷ + M ´ ç ÷ ú è ø è  ø ú  êë  û

� ᨨ矄��ᨨ

泐   ᨨ犨 ᨨ  ᆠᨨ 矄�ᨨ  ᨨ   �泐 쟼ᨨ ᨨ 㦨 ᨨ�ᨨ ⧤쟼 鼀�

l ҈ 和� q 㦨 ᔼw2  

l ҈ ҈ 鼀l 2 ҈ 鼀l    l w ω  Þ 鼀� ´ = 和�  㦨         ᨨ ᆠᨨ鼀  �  ᨨ ᨨ  

 ᨨ 矄 ҈  㡰 矄� � 矄 ᨨ鼀鼀ᨨ鼀 ᨨ � �ᨨ盐�O ᔼᨨ㦨ᔼᆠ鼀졔鼀  w = �  ( l ) =

=

䰘㝐  ��㝐  +  㝐 ´  㡰 㡰 =   



꾀��  鼀ᨨ鼀 ᨨ � � ᨨ盐 ᨨ� PIp㦨Iᨨ졔md



��㝐  ҈҈ 㝐  + 䰘㝐  㡰  =    㡰 s 鼀矄矄盐 � =

R/  O'

R ⏌ O

黨MR  黨MR  黨 - ҈㡰MR  =  MR  㦨  ҈  黨 ᆠ㡰 꾀矄犨├ ᨨ犨鼀ᨨ鼀 ᨨ � �ᨨ  �矄ᆠᨨ盐  �矄 矄矄� �  ᨨ盐�  ᔴ෌    �ᆠ盐 ᨨ�矄   㦨

Þ 鼀�

䰘



\ MI I㡰ᨨ  ᆠ盐ᨨ盐ᨨ�ᨨ ᨨ盐  �矄 矄矄� �  ᨨ盐�  O    �ᆠ盐 ᨨ     ᨨ  �矄ᆠ

㡰 㦨�ᆠ鼀



p R =M 黨  盐矄 ᆠᨨ 矄�    ᨨ 矄泐矄鼀 矄  ᆠᨨ鼀  �矄ᆠ ᨨ 鼀矄矄黨M  ��鼀矄矄 M矄盐�鼀ᨨ矄 ᨨ � 㝐ᨨ鼀  ᨨ � �  I ҈ 㡰 ᨨ    ᆠᨨ鼀 �矄ᆠ ҈  㦨 黨MR ᨨ盐    �矄 矄矄� �  ᨨ盐�  O    �ᆠ盐 ᨨ     ᨨ   �矄ᆠ MI ᨨ   ᆠ盐 ᨨ盐 ᨨ�ᨨ  ᨨ盐    �矄 矄矄� �  ᨨ盐� OἘ    �ᆠ盐 ᨨ   ᨨ  �矄ᆠ

æ Rö 

㦨 s ´ p ç ÷ 㦨 s ´ è ø

鼀   㝐ᨨ鼀  ᨨ  � � ᨨ   �矄ᆠ ᨨ盐   � �  �矄  �ᆠ盐 ᨨ�矄 ᨨ犨    ᔼ =





ᔼ Ἐ =

 鼀  

\

鼀  ᔼ ᔼ Ἐ = 



 





鼀  =҈ 



 ᆠ㡰 꾀矄 犨 ├ ᨨ犨 鼀ᨨ鼀  ᨨ  � � ᨨ   矄ᨨ�  ᆠ泐�  ᨨ盐    �矄 犨 �ᆠ  �矄  �ᆠ盐 �矄ᆠᨨ

mR  ml  +  ҈ mé l ù I = êR + ú ë û m é V l ù 㦨 ê + ú  ë pl  û I=

l Þ

dl m é -V l ù = + = dl  êë pl   úû

 pl      l l pl Þ  = ᨨ = pR  l =  R  R

V l =   pl

ÞV =

 

WWW.JEEBOOKS.IN

PS-67

System of Particles and Rotational Motion ҈

b㡰 㝐ᨨ鼀  ᨨ  ᔼ � ᨨ  ᆠᨨ鼀 �矄ᆠ ᨨ盐 Ἐ졠Ἐ ᨨ�  㝐  ᔼᨨ =   �盐矄ᨨ 鼀ᨨ  �矄ᆠ㦨 ⏌ \ 㝐矄矄 ᨨ 鼀ᨨ  �矄ᆠ 㦨 㝐⏌҈ ᲼꾀矄㝐µ 桌 㝐ᔼᨨ 鼀ᨨ  �矄ᆠᨨ盐�矄ᨨ犨  �矄 졠Ἐ㡰

�

b㡰 A' M

A

B'



㝐  㝐 æ  ö ҈黨 㝐  + ç ÷ = �҈ �҈ ҈ è  ø 㝐ᔼᨨ 鼀� � � �矄ᆠ 䰘 㝐  ҈黨 㝐  㝐   = �҈  �҈  R 㡰  a =    pR M ᨨ犨 =  M¢ a   pR   =  = p    æ  ö R÷ ç è  ø M M¢= p ᔼ鼀� � � =

   R MR  = Mr   Þ r㦨 ҈� �   㡰 s 鼀矄矄盐 �ᨨ   �矄ᆠ \ ᨨ 鼀矄矄 ᨨ   �矄ᆠ \

R/ 

㦨s맔pR㦨黨M 㝐矄矄 ᨨ  ᆠ�ᆠ盐 �矄ᆠ ᆠ盐

æ Rö 㦨 s ´ p ç ÷ è ø 㦨 s ´

M ¢a   

M æ  ö R÷ ´ç  p è  ø = MR =  黨 p  㡰 ᨨ   �  盐 � ᨨ鼀 矄⼄盐 矄 

ma  I҈㦨 I㦨 I 㦨 ҈

㝐w 㝐 + 鼀 和ᨨ� �犨�ᨨ矄矄� ⧤쟼 㝐鼀 w  㦨 㝐 + 鼀㡰

R ⏌



O

p R =M 黨



҈ æ Rö 㦨 ´ M ´ ç ÷ è ø  矄� �  �ᆠ盐  �矄  ᨨ鼀 \ MI I㡰ᨨ  ᆠ盐ᨨ盐ᨨ�ᨨ ᨨ盐  �矄 矄矄� �  ᨨ盐�  O    �ᆠ盐 ᨨ     ᨨ  �矄ᆠ   é҈ æ Rö æ R ö ù ú 㦨 ê ´ M ´ ç ÷ + M ´ ç ÷ è ø è  ø ú êë  û \ ᨨMIᨨ  矄泐矄鼀ᨨ盐  �矄矄矄� � ᨨ盐� O    �ᆠ盐 ᨨ    ᨨ   �矄ᆠ I㦨I҈I

I҈ I

҈   ᆠ㡰 ⧤� �ᆠ �泐 ᨨ�ᨨ 㡰⧤ 㦨 ᔼw  ҈  ⧤� �ᆠ �泐  矄�ᨨ 㡰⧤ 㦨 㝐  㝐ᔼ � ��㡰ᔼ� �㦨㝐 錐w� ��㦨w 㝐ᔼ 犨㡰ᔼ¢ 矄泐矄鼀㡰㦨 㝐  + 鼀  w¢ 矄泐矄鼀㡰 㦨

O'

҈  㝐ᨨ鼀 ᨨ � � I҈㡰ᨨ  ᆠᨨ鼀 �矄ᆠ㦨 黨 MR ᨨ盐     �矄 矄矄� � ᨨ盐� O    �ᆠ盐 ᨨ   ᨨ   �矄ᆠ MI ᨨ   ᆠ盐 ᨨ盐 ᨨ�ᨨ  ᨨ盐    �矄 矄矄� �  ᨨ盐� OἘ    �ᆠ盐 ᨨ   ᨨ  �矄ᆠ

㝐ᨨ鼀  ᨨ  � � ᨨ    ᆠ盐 ᨨ盐   ��   �矄



Y'

ᨨ矄ᨨ�  矄 鼀ᨨ鼀  ᨨ � � ᨨ盐 �鼀   IAB㦨 MR = I � ᨨ 矄ᨨ�  �矄ᆠ ҈     IA'BἘ㦨IYYἘ졔Mr㦨 Mr + Mr = Mr   IAB㦨IA'BἘ �� 㡰

㝐ᔼ ᨨ 鼀ᨨ  �矄ᆠᨨ盐 졠 ᔼ鼀ᨨ  �矄ᆠ㦨ᔼᆠ鼀졔鼀 

I=

M

r





B

R

҈ 㝐æ ö 㝐  = çè ÷ø =  ҈  �҈

=

Y

I

㦨 w㡰

䰘

  é҈ ҈ æ Rö æ R ö ù  ú 㦨 黨 MR - ê ´ M ´ ç ÷ + M ´ ç ÷ è ø è  ø ú  êë  û 黨MR  黨MR  黨 - ҈㡰MR  =  MR  ᨨ I㦨 㦨  ҈  㡰 㝐矄矄ᨨ  �矄ᆠ㦨㝐 ҈  ᔼ �矄ᆠ㦨 MR  \ 㝐ᨨ鼀  ᨨ � � ᨨ ᨨ  ⼄盐ᨨ  �矄ᆠ ҈ é҈ ù ҈  㦨 ê M 㡰 R ú = MR  ë  û

WWW.JEEBOOKS.IN

EBD_8341 PS-68



Physics

IXXἘ㦨

MR   + MR  = MR   

鼀矄矄M㦨Lr  �盐矄R㦨 \ 黨

ᨨ鼀⼄ 矄 �㡰  ��㡰

㡰 꾀ᨨ盐   �鼀ᨨ  ᆠ�ᆠ盐 ᨨᨨ � �㡰 ҈  I㦨 MR  矄� � �矄 ᨨ鼀 㝐ᨨ鼀 ᨨ � �ᨨ  ᨨᨨᨨ盐 XXἘ  �矄

L 錐 p



Lr æ Lö = ÷ è p ø p 

 

IXXἘ㦨 Lr㡰 ç

㡰 ᨨ鼀矄泐鼀鼀泐IAB㦨IAἘBἘ ICD㦨ICἘDἘ AἘBἘ ^ AB CἘDἘ ^ CD A' ᨨ鼀  ᨨ鼀 ᨨ C'

D

 �ᆠ盐 矄 Izz㦨IAB졔IAἘBἘ㦨ICD졔ICἘDἘ

q

A

Þ IAB㦨ICD \ 

B

O

IAB㦨ICD 㦨I

D'

C

B'

㡰 ᨨ 矄ᨨ�  矄  A  矄�泐

R

æ rö rA r 㡰 = k ç ÷ è Rø

dx

æ rö R

s

x

꾀 PB r㡰㦨K ç ÷ è ø

 

ᔴᨨ 矄�  矄 �ᆠ矄 ᨨ  �盐矄 x   �ᆠ├ 矄矄 dx 㝐矄矄ᨨ  矄 dm㦨  矄�泐맔 ᨨ盐鼀

æ xö = ç k ÷ p x  dx 㡰 è Rø 和ᨨ鼀ᨨ鼀 ᨨ � �ᨨ 矄 ᨨ盐�矄 �鼀

dI =

 dm㡰 x  

æ xö   ÷ p x dx 㡰 x  Rø

㦨 ç k è

æ p k ö � =ç x dx è  R ÷ø R

\

㝐ᨨ鼀 ᨨ � �ᨨ  矄 A I A = ò dI 

pk �  pk é x x dx = = ê ú ò R R ëê  úû  

I  = kml 

G

鼀ᨨ鼀 ᨨ � �ᨨ DEF㦨I҈ᨨ盐G 

D I ml  æ m öæ l ö ᨨ I҈ =  ÷ç ÷ µ ҈ ҈ è  øè  ø m⏌ B  I ADE = I BDF = I EFC = I  I �I \  I  + I҈ = I  Þ  I  +  = I  Þ I  =  ҈ ҈

和ᨨ I҈ µ ç

�㡰

R

æ pk ö é x҈ ù I B = � ò x dx = ç � ÷ ê ú è R ø ëê ҈ ûú R  

IB =

A

I  µ ml 

B

æ pk ö � \ IA = ç R è ҈ ÷ø 和�鼀�泐 ᨨ矄 B

\

㦨  é é  ù ù 㦨  ê MR + Ma ú +  ê MR ú ë� û ë� û 꾀  Ӹ  é ù      =M  㡰 + a ú =  ´ MR + Ma  ê� R � ë û  é æ ù  �ö - 㦨 � ê ´ ç ÷ +  ´ ú ´҈ ç ê � è  ÷ø ú ë û 㦨 � [  + ҈] ´ ҈ - = 黨 ´ ҈- 㦨N맔҈├�m \ 㦨黨  ҈҈㡰鼀矄矄ᨨ � �盐鼀� 㦨m  � ᨨ 矄�  㦨l  鼀ᨨ鼀 ᨨ � �ᨨ 鼀� ᨨ盐  �矄矄矄� �  ᨨ盐�  ᆠ ᨨ�  G  �ᆠ盐 ᨨ    

 ùR

R

pk

I B ҈  n = = = \n=  I A  ҈ ҈ ҈ 㡰  s    矄盐 ᆠ鼀矄矄  矄�泐 㝐ᨨ鼀  ᨨ � � ᨨ   鼀�  ᨨ盐  矄 矄矄� �  ᨨ盐�  Ἐ졠Ἐ ҈   IO㦨 s᲼p R 㡰 桌 ´  R㡰  é҈    ù êë  s p R 㡰 + s p R 㡰 ´ R úû ҈  㦨 psR  㝐ᨨ鼀 ᨨ � �ᨨ  鼀� ᨨ盐 矄矄矄� � ᨨ盐� ἘἘ IP 㦨 p s 졔sp  㡰맔  㡰  é҈    æ  ö ù ê s pR 㡰 R + s pR 㡰 ç  R㡰 + R ÷ ú è ø ûú ëê  㦨 p s ��s p 㦨҈�p s  I P ҈�psR  䰘 = = » \ ҈ IO psR  ҈   黨㡰   ᨨ盐矄 矄꾀ᔴ m㦨m㦨mᔴ㦨m㦨�├�   㝐ᨨ鼀  ᨨ  � � ᨨ    ᔴ 矄泐矄鼀 ᨨ盐   ��ᨨ  ᨨ   矄⼄盐 ᔼӸ 㦨ᔼ҈졔ᔼ졔ᔼᔴ졔ᔼ㦨ᔼ꾀졔ᔼ ᆠ鼀

R



 pk � R 

��㡰

A

l⏌ G m⏌

F

E

C

 ᆠ鼀ᨨ鼀 ᨨ � �ᨨ DECB� 鼀ᨨ ADE æ � I ö æ I ö ҈҈I  NI  =  I  + I҈ =  ç  ÷ + ç  ÷ = = ҈ è ҈ ø è ҈ ø ҈

 ᨨ盐ᨨ N㦨҈҈

WWW.JEEBOOKS.IN

PS-69

System of Particles and Rotational Motion 

҈ MR  

(20) 꾀矄犨├ ᨨ犨鼀ᨨ鼀 ᨨ � � �矄ᆠ I �矄ᆠ = w҈

w M

I҈ R҈㦨R

Iᨨ㦨I҈졔I㦨I졔I  ᨨ Iᨨ㦨I㦨2I \I㦨I I҈㦨I㦨I㦨I

 ᨨ Iᨨ ᆠ   ᨨ�   泐 � �  泐犨ᨨ � Iᨨ㦨I҈졔I㦨I҈졔I 㦨I҈졔I㦨I졔I 㦨I졔I㦨I졔I

w M

R҈ M㡰 R M㡰

I R㦨R/2

矄� �  �盐 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ

I҈w҈ + I w = I҈ + I  㡰 ´ w f æ MR  MR  ö + çç ÷wf  ÷ø è  ҈ ҈ æ MR  ᔼ ��⧤쟼 K � = I w = çç  è  MR  ´w+  = 

҈

ö  MR  w ÷÷ w =  ø

MR  w MR  w  � = ´ ҈ = 奠 = P奠   MR w X  F rF  ᆠ盐ᨨ P㦨 �㡰 a 㝐ᨨ鼀  ᨨ � � ᨨ   矄泐矄鼀 ᨨ盐  �矄 XE  I = I E + I F + IG E

a

rG Þ I = m rE 㡰 + m rF 㡰 + m rG 㡰  � �  æaö ma Þ I = m ´  + m ç ÷ + ma  = ma  =   èø \ N = �

a

G

 ҈�㡰  � ᨨ 㦨҈鼀



 �q㦨

҈  Iw   l ҈ æ ml  ö  Þ 鼀� l ´ ҈ = ҈ æç ml ö÷ w Þ 鼀�㡰 矄� ° = ç ÷w    çè  ÷ø   çè  ÷ø 

DPE = DKE ᨨ mgh =

Þ w = ҈�  ⏌矄



O

D

C 

㡰 KE ᨨ    矄  㦨  矄�ᨨ  KE 졔 ᨨ�ᨨ  KE

҈  ҈  mv + I w   ␔ I㦨 鼀ᨨ鼀 ᨨ � � w 㦨 꾀 �盐 ᨨᆠ�泐 ᨨ  ᨨ�ᨨ

m 㦨 鼀矄矄 ᨨ   矄  v 㦨 � ᨨᆠ�泐ᨨ ᆠ ᨨ 鼀矄矄 ᨨ 矄    Q 㝐ᨨ鼀  ᨨ � �ᨨ 矄  I = mR � ҈  ҈    \ K E = mv + ´ mR ´ w   �  v ö ҈ ҈  ævö æ Þ K E = mv  + ´ mR  ´ ç ÷ çQw = ÷ Rø   � è Rø è  ҈æ öæ v ö Þ KE = ç mR + mR  ÷ç ÷ è� øè R ø  ҈ 䰘 v 䰘 ҈ � Þ KE = mR  ´ ´ = ´ ´  � R  ҈  ҈ � Þ KE = ´ ҈  ᨨ盐  Þ⧤쟼㦨䰘�맔҈ᨨ盐 b㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  ᨨ �矄 鼀ᨨ  � ᆠ鼀 � ᆠ 㦨�ᆠ鼀  㦨҈ᆠ鼀 ᨨ   = ҈ 㦨�ᆠ鼀  �盐矄ᨨ ᨨ  =   ᨨ ᨨ 矄�� �    �ᨨ盐 ᆠ 㦨w \ ᨨᆠ�泐ᨨ 矄ᆠ㦨 ᆠ 졔w㡰 \ �矄 ᆠ鼀ᨨ 泐矄ᆠ㦨 ᆠ 졔w㡰

꾀矄矄盐鼀� � 矄泐鼀鼀�ᆠ 鼀�  ᨨ  �  xy   Ix 㦨 Iy 泐矄泐鼀鼀泐 Ix졔Iy㦨Iz  �ᆠ盐㜠 �矄 ᨨ鼀㡰

 ö æ ö æ = ç ᆠ  + ᆠ  ÷  çQ w = ÷ è ø è ø

Iz B =  Ma  A Ix㦨Iy㦨 a  a졔a=2a Q Iz㦨҈Ma �� 㡰 a ᨨ犨 ᨨ鼀 ᨨ 㜠 矄 X  ᨨ鼀 O  IAB㦨Ix졔M a㡰 㦨Ma졔Ma 㦨Ma bᆠ㡰 和� ᆠ ABCD �矄  矄⼄盐 鼀�    ᆠ 泐 矄泐鼀鼀泐I҈㦨I I㦨I ᨨ鼀  �ᆠ盐  矄  ᨨ鼀 㝐ᨨ鼀  ᨨ  � � ᨨ盐    �矄  �ᆠ盐 ᨨ 矄⼄盐    矄矄� � ᨨ鼀ᆠ  O

=

Y



B

=

҈ æ MR  MR  ö ҈  MR  w + ç ÷ w =  ÷ø � �  çè  ᆠ � ᨨ矄矄 � ├� �ᆠ  �泐 奠 ᨨ矄矄

䰘

҈

Topic-5 : Rolling Motion  Þ wf = w �

� ⧤쟼 K f =

�

 A

ᆠ   ×  = ´ � = 䰘� ᆠ鼀   꾀

x 㦨

ᨨ

 ᨨ �ᆠ鼀

꾀 

҈ᆠ鼀



ᆠ㡰 ᨨ 矄  ҈  ҈ mv 졔ᔼw㦨 mgh    䰘v  ҈  ҈ æ öv ᨨ mv 졔 ç mR ÷  = mgh ᨨh㦨 ҈ g   è� øR

WWW.JEEBOOKS.IN

EBD_8341 PS-70

Physics

ᨨ ᆠ泐� 

䰘

҈  ҈ æ mR  ö mv + ç ÷ = mgh Ἐ   çè  ÷ø h 䰘v  ⏌ ҈ g ҈ = = \ h Ἐ v  ⏌  g ҈� 

ᨨ

҈  ҈ mvcm + I cm w    I cm ö  ҈æ ҈  ҈ æv ö = mvcm + I cm ç cm ÷ = ç m +  ÷ vcm  R   è R ø è ø mR  ö  ҈æ ᨨ� �鼀�  =  çç m +  ÷÷ vcm R ø è  v \ h = cm  g mR  ö  ҈æ ÷ vcm ᨨ矄ᨨ� ᆠ泐� mgh =  çç m +  R  ÷ø è v  \ h = cm g ҈æ  mR  ö  m = + ç ÷ vcm ᨨ矄  mgh  ç � R  ÷ø è 䰘v  \ h = cm ҈ g



 䰘  Þ  ҈� ҈  ҈



 㦨鼀

mR a  ��㡰  ᨨ盐ᨨ� � 㦨a  ���㡰 ᨨ鼀 ҈㡰 㡰  㡰 mRa  F = maR  F = mRa   F a= mR ᆠ㡰 꾀矄矄 ᨨ犨 �   ��鼀  ᨨ鼀ᆠ�ᨨ ᨨ 꾀 ᨨ ᨨ犨�矄 � ᨨ犨 矄졠

�矄犨� ᨨ � �ᨨ  矄泐矄鼀ᨨ ᆠᨨ 矄ᨨ盐   







a







黨

ᆠ㡰

҈

ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀 ᨨ盐  泐 � ᨨ�  ᨨ    矄盐 ᆠ mrw㦨mrw w r  [Q v = r w ] Þ w㦨w⏌ Þ v =  㡰 꾀泐� �  �泐 ᆠᨨ 矄�ᨨ  � ᆠ� ᨨ

 㦨ᔼa㦨



 �㡰

mR F 㝐矄矄㦨m a = fR 졠  aù é mR  a = fR  êQ a = ú f Rû ë  R ma = f  ��㡰  盐  �矄 盐 �  ⼄盐�ᨨ  �㡰 ma ma ma 㦨 F   ᨨ F =   㡰 꾀矄犨├ ᨨ犨 鼀� 矄� q 꾀ᆠᆠ�ᨨ   = ᔼ 鼀+  㝐 ᆠ � 矄� qᆠ 㝐 ᆠ � 矄� qᆠ ᨨᆠ泐�   ᆠ =  㦨 ҈ 㝐ᆠ 㝐ᆠ  㝐ᆠ + 㝐 + ᆠ      ᨨ ᆠ㦨 � 矄� qᆠ  ᨨ 矄  㝐 � 矄� q矄 㦨 㝐矄 � 矄� q矄 矄 = 矄 ᔼ  㝐  㝐矄 + 㝐 矄 + 矄 �   �  矄 = � 矄� q矄 ᨨ 䰘 �� ᆠ㦨矄 � � 矄� qᆠ 䰘 ҈�  � � = = � 矄� qᆠ = � 矄� q矄 \ 矄� q矄  ҈  䰘 � 

 �㡰 



ᆠ㡰 ᨨ鼀 ��盐 ma 㦨 F  f 꾀  ᨨ⼄盐 t 㦨 Ia 

ᨨ 盐矄㡰 mgh =

�ᨨᨨ  �� 矄 ҈ �

v  hἘ = g

æ v  ö ҈  ҈  mv + I w = mg ç ÷   è g ø ҈  ҈ v   mv + I  = mv ᲼Qv㦨 w桌 \   R   ҈ v  ҈ ҈ ҈ I = mv  - mv  = mv  Þ I㦨 mR  \  R    

�矄�矄 鼀ᨨ鼀 ᨨ � �ᨨ   �矄ᆠ  ᆠ ᨨᆠ�矄 �矄ᆠ ҈҈ b㡰 ᔼ 盐 ᨨ� �   ᨨ�  ᨨ ᆠᨨ ᆠ �矄   � 矄  ᨨ盐矄 ᆠ  ᨨ  ᨨ�ᨨ  ᨨ    �ᆠ矄 ᨨ    �矄ᆠ졠 泐� �v㦨rw ␔ � w�矄矄鼀 ᨨ �ᆠ矄  vµr rQ  rC  rP \ rQ  rC  rP

WWW.JEEBOOKS.IN

PS-71

System of Particles and Rotational Motion b㡰 ᔴ泐�  ᨨ  鼀ᨨ� � ᨨ   �ᆠ�ᨨ 矄矄 矄盐 ᆠ ᔼ

ᨨ   ᆠ矄矄 ᨨ 盐 ᨨ ᨨ犨    ᆠᆠ�ᨨ  ᨨ    ᆠ ᨨ 鼀矄矄 ᨨ   ᆠ泐�  �矄 � 矄�  q 꾀矄ᨨ ᨨ ᨨ⼄盐 ᨨ盐 ᆠ ᨨ ᆠ泐� �矄 ᆠ� �ᨨ  ᆠ泐� 矄� ᆠ 犨 矄矄盐鼀    矄盐 ᆠ ᨨ �ᆠ�ᨨ 矄矄     ᨨᆠ矄 ᆠ� �ᨨ  ᆠ泐� �矄鼀� 犨 �ᆠ 矄矄  ᨨ盐�    ᆠ  ᨨ F ᆠ泐�   ᨨ    g s�nq ᨨ� ᨨ N 鼀ᨨ鼀  ᨨ    ᨨ�  ᨨ ᆠᨨ ᆠ ᆠᨨ ᆠ �  ᨨ    ᆠ矄矄 �矄 g s�nq �    ᨨ犨 犨  �ᆠ�ᨨ

   ᆠ   �ᆠ�ᨨ  mg s�n q ᨨᆠ 犨泐矄 ᆠ矄 �    mg q 盐犨  �ᆠ�ᨨ  ҈ ᆠ㡰  盐 ᨨ � F ᨨᆠ ᨨ鼀 ᆠ�ᨨ  矄 � 矄 L N G ᨨ ᨨ  ᆠᨨ  꾀  �矄 矄�盐�ᨨ    ᆠ盐�ᆠ ᨨᆠ├ L⏌ 矄矄ᨨ� � ᨨ盐ᨨ� O O 꾀ᨨ盐 ᨨ�  졠 ᨨ⼄盐 mg L mg F맔L㦨mg맔  Þ F㦨    ᆠ鼀� �鼀盐鼀 ᨨᆠ⼄盐�  ᨨᨨ ᨨᆠ├ mg F=  ҈ 䰘㡰 K.ETᨨtalᨨ ᨨ� � �矄ᆠK.Etrans 졔K.Erᨨt ҈

 ҈  ҈  ҈  ҈ æ ҈ mR  ö æç v ç ÷ 㦨 鼀 졔 ᔼw 㦨 mv 졔   ø çè R      è

ö ÷ ÷ ø

  mv  ᨨ 矄盐 ᆠ AB k.E�졔 ᨨ矄矄 � ���ᨨ  ᨨ �  �泐㦨 K.Ef   m 㡰졔mg 㡰㦨 m VB  �㡰   ᨨ 矄盐 ᆠ CD   m v㡰졔mg 䰘㡰㦨 m VD  ��㡰   Q VB㦨VD\ ᨨ鼀⼄ �㡰  ��㡰   m 㡰졔mg맔㦨 m v㡰졔mg맔䰘   \V㦨䰘m/s ҈� 㡰

 矄�ᆠ├ �矄 㡰 ᨨᆠ矄ᨨ ᨨ�  ᨨ ᆠᨨ ᆠ 졠 ᨨ   � � 犨�  �ᨨ盐   矄 ᨨ矄�  盐   �ᆠ�ᨨ  ᨨᆠ f ᨨ矄 ᨨ ᨨ犨  �矄   ᆠ矄  ᨨ⼄盐 ᨨ盐 ἘᆠἘ 犨 �ᆠ 矄矄ᨨ� � � �犨  � � 矄�ᆠ├ �ᆠ�ᨨ

ᨨᆠ f҈ 矄ᨨᆠ矄 Ff㦨ma f㦨맔 \ f㦨҈ C 꾀泐� � t 㦨Iaᨨ盐 C  R R f҈ a ff҈㡰R㦨Ia㦨 I f R 졠 ᲼Q a㦨Ra桌  ᲼Q I㦨MR桌 Þ ᲼҈m맔桌맔�㦨맔 �㡰맔 � P  \ m㦨㦨 㦨 \ P㦨 ҈ ҈ K.ETᨨtal㦨

҈ �㡰 ᨨ  ᨨ ᨨ矄�  F㦨mmg㦨鼀� ᨨ ᨨ ᨨ� �

a æa ö F ç + b ÷ £ mg   è ø a æa ö Þ  mg ç + b ÷ £ mg Þ a졔b£�a   è ø b  Þ £ a  �b£䰘�a盐 �矄�矄 ᨨᨨ矄矄� 꾀矄 鼀 �鼀盐鼀盐ᨨ bᆠ ⼄盐ᨨ�a ҈b Þ = � a ҈䰘 䰘�㡰

 �鼀├  ᨨᆠ    �ᨨ盐  ᨨ 矄ᆠ

t=

҈ h æ K  ö ç҈ +  ÷ 矄� q g çè R ÷ø h K Q  =҈ g R

ᨨ� � t҈ =

҈ h  (҈ + ҈) = 矄� ° g 

ᨨ �矄ᆠ t  =

҈ h æ ҈ ö h K ҈ + = = ҈ Q ç ÷ 矄� ° g è  ø g R 

෌� t҈ - t = \

 

-  ҈

h  -  h = g g ҈

Þ  h - h =  -

 

  \ h » 䰘� 鼀 �� ᨨ  ᨨᨨ  � ᆠ�   㡰 ҈ 矄 ᨨ ⧤� �ᆠ  �泐ᨨ    � � E҈ 㦨 K.E.㡰 ᨨ�ᨨ 졔 K.E.㡰  矄�ᨨ  ҈  ҈  㦨 I w + mvc   ҈   ҈  㦨 ´ mr w + m r w 㡰 Q I㦨mr vc㦨rw)   Þ h ҈䰘㡰㦨҈䰘҈�Þ h =

  E҈ = mr w  ᨨ ├� �ᆠ �泐ᨨ   ᆠ泐�  E 㦨 K.E㡰 ᨨ�ᨨ 졔 K.E㡰  矄�ᨨ 

҈ ҈ I Ἐ w Ἐ + Mv Ἐc   ҈æ҈ ö   ҈  㦨 ç Mr ÷ w Ἐ + M r w Ἐ㡰 è ø       E㦨 Mr w Ἐ  쟼⼄盐� �E҈㦨E    mrw㦨 Mr w Ἐ   m   wἘ = = ´ = ҈ Þ wἘ㦨w Þ   M   w  ᆠᨨ � � ᆠ泐� 犨�ᆠ  矄鼀�鼀

㦨

WWW.JEEBOOKS.IN

EBD_8341 PS-72

҈黨



Physics

ᆠ㡰 ᔼ   ᨨᆠ 㡰�矄 �   � �    t 鼀� 矄ᆠᨨ 矄   t 㦨 맔  ᔼ  ᨨᆠ�矄�  ᨨ鼀 ᨨ     矄   犨 矄 ᆠ�鼀矄       �ᆠ盐 �矄 ᆠ 㝐¢ ᨨ  ᨨᆠ  ᨨ鼀 턼 犨� �ᨨ 㝐 ᨨ  ᆠ  �� � � ��泐   �ᆠ盐 �矄 턼㝐 턼 � ᆠᨨ鼀矄 턼㝐Ἐ ᔼ   ᨨᆠ 㡰�矄�

ᨨ鼀 ᨨ   ᆠ�ᆠ盐鼀  ᆠ  ᨨ�     t �矄 ᨨ ᔼ   ᨨᆠ 㡰�矄�  � �泐ᨨ� 和 

t = F ´ R   犨 ᆠ�鼀矄 r b㡰 ᨨᆠ�泐ᆠ Ἐ졠Ἐ \ vo = Rw iˆ R w ᆠᨨ矄º kˆ 

R w  R w 矄� º -�ˆ 㡰 



҈

º

ur Rw Rw VP = Rw�ˆ 矄� °�ˆ + ᆠᨨ矄 °kˆ   ur Rw ˆ ù  Rw ˆ é �ú+ k \ VP 㦨 êRw �ˆ  û  ë ur ҈҈  R kˆ ᨨ VP = Rw �ˆ +  ur  w bᆠ㡰  VA =  V C = V  ur ur VB = V ur ur VC = V ur ur VB = V \ VC -VB ur ur = VB -  VA

ur



R w �ˆ

ur

ur

ur

F

m f҈

f

mgᆠᨨ矄q

 ᆠ �ᆠ�ᨨ  ᨨᆠ � 矄 ᨨ�ᨨ  盐 � 矄  矄�ᨨ  鼀ᨨ�ᨨ  꾀泐� � F 㦨 ma ᨨ �   �ᆠ�ᨨ  ᨨ � ᆠ�     mg矄� q f㦨mac 犨  ac 㦨 ᆠᆠ�ᨨ  ᨨ ᆠ  ᨨ 鼀矄矄 ᨨ    ᆠ泐�  \ f㦨mg矄� q mac … �㡰 g 矄� q g 矄� q  = = g 矄� q 盐ac 㦨  Ic  mR ⏌  ҈+ ҈+  mR mR  mg 矄� q f㦨  ᔴ泐�  q �矄 盐ᆠ  �ᆠ�ᨨ  ᨨᆠ�矄  盐ᆠ 

a



a҈ 

和� ᆠ  �矄 ᨨ 矄�� �  泐犨  \ a҈㦨a

VA = 

  V C - V A  =   V B - V C  N ᆠ 㡰  矄� � � �ᆠ�ᨨ

ᆠ矄 �    ᨨᨨ矄� �ᆠ�ᨨ  ᨨ  鼀� 矄�  q ᨨ ᨨᨨ矄   � 鼀ᨨ�ᨨ  q ᆠ盐矄ᨨ  �ᆠ�ᨨ  ᨨᆠ 

q 矄� g mg m ᆠ泐�  ᨨ矄 q

 㡰 ᔼ ᆠ矄ᨨ 盐ᨨ� �ᨨ � ᆠ�   ᆠᆠ�ᨨ

ᨨ   ᨨ 泐 � 矄� q = ᔼ ҈+ 㝐  ᔼ 㝐  ᨨ ᨨᨨ犨 ᆠ泐�  = =҈ 㝐  㝐  ҈ 㝐  ᔼ ҈  ᨨ矄ᨨ� ᆠ泐�  = =    㝐 㝐  ᆠ ᆠᆠ�ᨨ   ᨨ 矄ᨨ�  ᆠ泐�  �矄 鼀ᨨ    ᨨᨨ犨 ᆠ泐�      ᨨ 矄ᨨ� ᆠ泐�  犨� ᆠ    ᨨᨨ鼀 ᨨ  � ᆠ�     �矄 ᔼ  ᆠ矄ᨨ ᨨ� � 犨� ᨨ犨ᨨ├ ᨨ 泐 �ᆠ�ᨨ 

 ᨨ ᨨ 鼀ᆠ  �ᆠ  �泐 鼀� 矄 ᆠᨨ 矄  \ ⧤쟼㡰矄ᨨ� 㦨 ⧤쟼㡰 ᨨᨨ犨㦨 ᆠ矄� 쟼㦨鼀�   鼀  �矄  ᨨᆠ ᔼ矄 ᨨ� ᨨ  ᆠᨨ鼀ᨨ   F 盐矄 矄    ├  ᆠ  ᨨ�  ᨨ ᆠᨨ ᆠ ᨨ    ├ 犨�    ᆠ泐�  犨�   ᨨ 鼀ᨨ ᨨ犨 矄 ��    �ᆠ�ᨨ  ᨨᆠf҈犨�ᆠᨨ犨 矄 ᨨ   ├  f҈ 㦨 �ᆠ�ᨨ  犨   ├   ᆠ泐�  f 㦨 �ᆠ�ᨨ  犨  ᆠ泐�    �ᨨ盐 a҈㦨ᆠᆠ�ᨨ ᨨ  ├ a 㦨 ᆠᆠ�ᨨ  ᨨ ᆠ ᨨ 鼀矄矄 ᨨ ᆠ泐�   a㦨  �盐 ᆠᆠ�ᨨ  ᨨ  ᆠ泐�  ᨨ盐 �矄 ᔴ㝐 f҈

F - f҈ a҈㦨 m f҈ - f  a㦨 m҈ f҈ - f  㡰 R f҈ - f  㡰 R a= = ҈ I m R  ҈  f҈ - f  㡰 a= m҈R  f҈ - f  㡰 a㦨Ra = m҈ 㡰 和ᨨ� �⼄矄 �㡰ᨨ 㡰犨�

f

 �㡰  ��㡰  ���㡰

 �㡰  㡰

F m҈ + m 꾀  꾀ᆠᆠ�ᨨ  ᨨ  ᆠ  ᨨ  鼀矄矄 ᨨ  ᆠ泐�  F a = m҈ + m m҈F 㡰 �ᆠ�ᨨ 犨  ├ ᆠ泐�  f҈ = m҈ + m m҈F �ᆠ�ᨨ 犨 ᆠ泐�  �ᨨ盐  f  = m҈ + m 和� ᆠ  ⼄盐 ��矄  ᨨ矄��  泐  ᆠᨨᆠ泐 矄 ᨨ犨  �  ��盐矄 꾀ᆠᆠ�ᨨ  ᨨ  ├ a҈ =

WWW.JEEBOOKS.IN

PS-73

System of Particles and Rotational Motion �

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈

㡰 鼀 �鼀盐鼀盐ᨨ ⼄�⼄鼀   ᨨᨨ�矄ᨨ盐 ᨨᨨ  㦨   ᨨᆠ矄 鼀� ҈㡰鼀盐矄矄矄  ᨨ盐�  ᆠᨨ ᆠ ᨨ�  ἘἘ 졠턼   = ᨨ矄� q鼀  = \ ᆠᨨ矄 黨 q鼀 㡰 = 졠 졠 q 鼀 턼  

ᨨᨨ  鼀�







鼀�

q

b㡰 꾀 �盐鼀ᨨ鼀 盐鼀 ᨨ L 㦨 Iw ᨨ盐  �矄 ᨨ  ᨨ 㡰 㝐ᨨ鼀  ᨨ  � � ᨨ    ᨨ 㜠 � 矄ᆠ 矄泐矄鼀 I 㦨 Iᨨ  졔 mx 㦨 Iᨨ  졔 mvt m 㦨鼀矄矄ᨨ � 矄ᆠ \ L㦨 Iᨨ 졔mvt㡰w

q鼀

w

(

x㦨v t

dL =  mv  t w㡰 ᨨ  t µ t dt �  �  �矄 矄��  � 矄矄� �  ᨨ盐�  ᨨ���  꾀 �鼀TL 㦨ᆠᨨ 矄  dL = \  t ᨨ dt �犨   � 矄ᆠ矄ᨨ矄鼀ᨨ� �L ᨨ矄 ᨨᆠ  �   ᨨ T ᆠᨨ鼀矄 ᆠᨨ 矄  㡰 ␔   犨  ��� �    �盐 ᆠᆠ�ᨨ  a㡰 ᨨ   ᨨ      矄 � 矄  ᨨ盐矄 ᆠᆠ�ᨨ  ᆠ� 矄 㦨 La     矄    ᆠ泐 ᨨ 鼀ᨨ 犨泐  ᨨ鼀   ᆠ  盐 盐 ᨨ   �ᆠ�ᨨ  犨          ᨨ   �矄 ᨨ矄 ᨨ   ᔼ  � 矄  ᨨ盐矄  �盐 ᨨᆠ�泐�矄 w  

 ᆠ矄矄泐 �ᆠ�ᨨ  ᨨᆠ �矄 ᨨ�   泐 �ᆠ�ᨨ  ᨨᆠ mLw㦨Ҙ ma㡰ÞmLw㦨ҘmLa Þ w㦨Ҙa

\

at㦨Ҙa Þ t㦨 a



㡰

a

v

Ҙ a

mv  T 矄� q 㦨 �矄 ᨨ 盐ᆠ� � r

M

r w

q

T q

Tᆠᨨ矄q

T矄� q

mg

  ᆠ矄矄泐ᆠ � ᨨᆠ ᨨ ᆠ�ᆠ盐 鼀ᨨ�ᨨ



L

)

Tᆠᨨ矄 q 㦨mg

v  ҈ ´ ҈ = = ҈ ᨨ q 㦨� rg ҈ ´ ҈ 㡰  ᨨᆠ ᆠ� � ᨨ    鼀矄矄 ᨨ �⼄盐�  dm ᨨ  � dx  �矄 ᆠx ᨨ鼀  �矄ᨨ ᨨ�ᨨ O æ mv  ö ÷ dF㦨 dm㡰xw  çQ F = r ø F è \

C

M

 q 㦨

x

O

O

a a ᨨ r =  泐�ᨨ鼀泐   ᨨ⼄盐ᨨ盐 ᨨ� O �矄 ᨨ  ᆠ  �盐 鼀ᨨ鼀 盐鼀 L㡰ᨨ盐 O �矄 ᆠᨨ 矄  ᨨL�㦨Lf æ aö  MV ç ÷ = I  w = Icm + Mr 㡰w è ø ìï Ma  æ a  ö üï v   + M ç ÷ ý w  = Ma w 㦨 w㦨 í  a è  ø þï îï  r㦨

䰘

a

矄� �w㦨w졔at Þ w㦨at

dW = dx ҈x  d é  w \ x + ҈䰘 - ҈黨 x ù úû  dx êë 䰘├� Þ x҈黨㦨 ҈黨 = 黨 鼀 \ x㦨  ᆠ㡰 ᨨ�矄盐 �ᨨ� �ᆠ�ᆠ盐鼀ᨨ�ᨨ 矄 ᆠ�矄 鼀ᨨ� �� ᆠ�ᆠ盐 ᨨ� ᨨ ᆠ├犨�  ᆠᨨ 矄 矄 

 ᨨ �矄 盐    � 盐 ᆠ ᨨ 犨ᨨ ᨨᆠ矄 �㡰  矄�ᨨ  T �   ᨨ v ��㡰 ␔��  ᨨ  ᨨ mg ᨨ犨ᨨ├ ᨨ ᨨ鼀� �鼀盐鼀

ᨨ犨  t  =



ᆠ㡰 꾀矄 � �矄  ᨨ  ᆠᨨ�矄�ᨨ  犨  犨ᨨ �  �ᆠ 矄 矄  泐 犨�  ᆠ  �  � �  ᨨᆠ��矄 和� ᆠ  矄 矄矄鼀ᨨᨨ  犨� ᨨ �ᆠ�ᨨ  ᨨᨨ⼄盐㡰    ᨨ 犨� ᨨ 矄 ᨨ  �盐鼀ᨨ鼀 盐鼀

盐矄 A   ᆠᨨ�矄�ᨨ  犨� 鼀�  犨�  �矄 � ��  �盐 鼀ᨨ鼀 盐鼀 � w A = w  wB =  ᆠ㡰 ᨨᨨ� 鼀矄矄I㦨mr 㝐ᔼ ᨨ  矄泐矄鼀ᨨ盐 �矄 ᨨ ᨨ�ᨨ  O I㦨I҈졔I㦨x졔䰘 ҈x㡰 㦨x졔䰘 ҈黨졔xx㡰 㦨x졔҈䰘҈黨x

 犨ᨨ├ ᨨ  �  ᨨ� �   ᨨ  �矄 ᆠᨨ   � ᨨ �矄 ᨨ�ᨨ  ├� �ᆠ  �泐 ├� ҈  \ W㦨 I w  x ҈   = ᲼ + ҈䰘 ҈黨 桌 w x x  졠 

M dx dF dx ´ xw   L 졠 M 犨  �矄� 鼀矄矄  矄�泐ᨨ �⼄盐�  L \  ᨨᆠ ᆠ� �    ᨨ    �矄 ᨨ   犨 ᨨ �⼄盐� � 盐 LM  M  L w x dx = w ò x dx F㦨 ò   L L \

dF㦨

L

ù MLw  M  é x ù M  é L w ê ú = w ê - ú = 㦨 L  ëê  úû  L ëê  ûú

WWW.JEEBOOKS.IN

EBD_8341 PS-74

Physics

҈ù é  êF ´ r ´ ú = I a û ë ҈ ҈  ´ � ´ � ´ 㦨 ´ ҈� ´ � ´ � ´ a   Þa㦨 矄҈ w㦨w졔atÞw㦨졔맔҈㦨 矄҈ ҈ ␔     ᆠ盐 �� 矄 ᨨ � ᨨ盐    �   ᨨ鼀 ᆠ�ᨨ  N 犨� 矄矄  ᨨ盐�     � D ᨨ盐 犨 �ᆠ ᨨ�ᨨ ├矄ᆠ 鼀ᨨ鼀 矄 盐ᨨN  �ᆠ�ᨨ   ᨨᆠf犨� ᨨ

├� � 鼀ᨨ鼀  ᨨ  ᨨᆠ B C  鼀�ᨨ盐 D F 黨

҈

㡰

 a a = mg ´ \ F㦨 mg  a⏌    A f D  a mg  ᆠ鼀� �鼀盐鼀盐ᨨ F㦨 mg   t 矄ᨨ⼄盐t㦨Ia \a㦨 I t 㦨 F ´ r ^ ᨨ⼄盐 �矄 矄鼀 �  ᨨ   ᆠ矄矄 盐 矄� ᆠ I 犨�  �   盐 ᨨ �   鼀矄矄 �矄�盐�ᨨ  ᨨ盐   �矄矄ᨨa犨� �    b ᆠ㡰   ᨨ �矄 矄  ᨨ鼀 矄 矄ᨨ   �  矄 泐 ᨨ� � ᨨ盐 �矄 ᆠᨨ ᆠ ᨨ�  犨�    ᨨᨨ 犨� ᨨ盐 矄�� �

㡰 꾀矄 犨 ├ ᨨ犨 ᆠᆠ�ᨨ  ᨨ    ᆠ  ᨨ  鼀矄矄 ᨨ ᆠ泐�  ᨨ� � ᨨ犨    � ᆠ�    

g 矄� q I  ҈+ MR  ᔼ ᆠ矄 ᨨ P  鼀矄矄 �矄 ᆠᨨ ᆠ 㜠  犨泐 ᨨ鼀  �矄 和ᨨIP>IQ \ aPaQ Þ vv턼Þww턼 ҈

҈

ac

ᆠ㡰   �盐 �鼀盐矄 ᆠ  泐   �ᆠ�ᨨ  ᨨᆠ 犨  � �   矄ᨨ ᆠ矄  �盐 矄  w ᨨ  � � ᨨ盐 졠 òt 

F맔

҈҈

C

ac =

 㦨㜠矄 ᨨ 泐㦨҈矄



҈�

꾀  ᆠᨨ�矄�ᨨ w ᆠ矄矄盐  � � 鼀� 矄ᨨ� � �

   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ   ᆠ  �ᆠ�ᨨ  犨    � �    �ᨨ盐    ᨨ�  ᨨ ᆠᨨ ᆠ �矄 ᨨ     ᆠ 㡰 꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ � 鼀ᨨ鼀 盐鼀� P�㦨 Pf m v㡰졔m v㡰졔m맔㦨 m졔m졔m㡰vc Þ vc㦨 + -

m

a

v a

a

v m

⏌  ᆠᨨ矄 



ar

 

at

arᆠᨨ矄 졔at ᆠᨨ矄

෌�  �  ├� �ᆠ �泐㦨 ᨨ矄矄 �  ᨨ �  �泐

҈  l Iw 㦨鼀� ҈ᆠᨨ矄 㡰   l ml   � \ w 㦨鼀� Þ w㦨   l ᨨ犨t㦨ᔼa ҈ l  � \ 鼀�맔 矄�  㦨 鼀la Þ a㦨    l l  � 盐 㦨 a㦨   � l l � ´ 㦨 꾀矄ᨨ 㦨w 㦨   l   ᨨ �ᆠ 鼀ᨨ�ᨨ  ᨨ ᆠ  ᨨ 鼀矄矄 鼀�㦨鼀 ᆠᨨ矄 졔ᆠᨨ矄 㡰 \

é � ҈  � ù ´ ú 鼀�㦨鼀 ê ´ +   û ë 

\

㝐� 㦨 ҈

҈

ᨨ犨 泐� � ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀 ᨨ盐 ᆠ ᨨ 鼀矄矄 � L�㦨 Lf mv맔a졔m v㡰맔a㦨Iw ҈ I㦨 m㡰맔 a㡰졔m맔a졔m맔a㦨ma ҈ v  \ mv ( a ) + m ( v ) ´  a = ma ´ w Þ w = �a ҈  I w \ 꾀 ᆠᨨ�矄�ᨨ  �泐E㦨    v mv ҈   = 㦨 ´  ma ´  � �a  r dr r r 㡰  r t 㡰 = at�ˆ + btˆ ® v 㦨 dt 㦨 a�ˆ + bˆ 㦨 ᆠᨨ 矄  r a 㦨 \ r r 盐  P = mv  㦨 ᆠᨨ 矄 

҈  鼀 㦨 ᆠᨨ 矄   r æ ¶U ˆ ¶U ˆ ö F = ç �+  ÷ 㦨 ¶y ø è ¶x

 ⧤㦨

\ 㦨ᆠᨨ 矄  꾀矄ᨨ쟼㦨⧤졔㦨ᔴᨨ 矄  r \

dL r r r = t= r´F =  dt

Q ar  �矄 ᆠᨨ 矄 㡰

r

\ L  㦨 ᆠᨨ 矄 

WWW.JEEBOOKS.IN

PS-75

System of Particles and Rotational Motion

r r dr r ˆ ˆ v = 턼 r t 㡰 = a ᆠᨨ矄 wt � + b 矄� wt  ® dt = -aw 矄� wt 㡰 ˆ� +bw ᆠᨨ矄 wt 㡰 ˆ r r dv r a= = -w ᲼a ᆠᨨ矄 wt �ˆ + b 矄� wt ˆ桌 = -w  r \ dt r r r r r 꾀矄ᨨ t = r ´ F =  \ 㦨ᆠᨨ 矄 㡰 \ r  F   ҈҈㡰

⼄㡰 �  鼀ᨨ矄 盐 X 矄ᨨ鼀ᨨ矄 盐     ᨨ   ���ᨨ  �泐ᨨ X�矄   ᆠᨨ � 盐ᨨ盐矄泐 � ᆠ矄� � T ᨨ  犨��  ᨨ  Y ᨨ盐 P 矄     �ᆠ盐 �矄 ᆠ ᨨ    �  ᨨ  ᆠ�ᨨ ᨨ  ᨨᆠ ᨨ鼀 ᨨ� P�矄 ᨨ Ӹ ᨨᆠ  泐Xᨨ  Y 㝐� 㦨 Mg + Mg = mg 犨 Mg�矄犨  ᨨ Y Mg�矄  ᨨᆠᨨ Y 盐ᨨZ. 㡰 Mg

r r uur mw r  DU = - ò F dr = + ò mwrdr = \Uµr  

꾀矄ᨨ = a  ᆠᨨ矄 wt + b  矄�  wt \ r㦨f t㡰 ᨨᆠ�矄ᆠ \쟼㦨 r dr r r ˆ ˆ  r t 㡰 = a t� + 矄� w t ® v 㦨 dt ˆ ᲼ 矄�

t � ᆠᨨ矄 t ˆ 桌 a w w + w w 㦨 \ 㦨aw㦨ᆠᨨ 矄  r r 㦨 dv 㦨aw᲼ᆠᨨ矄wt ˆ 졔矄� wt ˆ 桌 � a dt r a 㦨 w  rr \ r r r t 㦨 r ´ F 㦨 \ 㦨ᆠᨨ 矄  ᨨᆠ�矄ᆠ �  盐  ᆠ ⧤矄ᨨᆠᨨ 矄  r dr b  r 和 r t 㡰 = a ᆠᨨ矄 w t�ˆ + t ˆ ® vr 㦨 㦨 at �ˆ + bt ˆ \㦨f t㡰 dt  r a 㦨 bˆ 㦨ᆠᨨ 矄  r r F 㦨 ma 㦨 ᆠᨨ 矄 

 鼀 � 

\  ᨨᆠᨨ Y�矄 ᨨ� Mg = B + Fv B졔Fv  泐Xᨨ Y

 ���ᨨ  ᨨ �  �泐 ᨨ  X �矄 ᆠᨨ � ᨨ盐矄泐� ᆠ矄� � ᆠ盐矄矄 Y 鼀ᨨ矄 ᨨ犨   ᆠ ᨨ 鼀矄矄 ᨨ X 鼀ᨨ矄 盐

҈

N f

҈黨 q

q

mgᆠᨨ矄q mg

㦨   q + ҈ 㡰 mg ᆠᨨ矄 q = 矄ᆠ qmg ᆠᨨ矄 q = mg 㦨犨�� ᨨ Y 꾀��  盐 ᨨ  矄 ᆠ ᨨ  �ᆠ�ᨨ  ᨨᆠ 犨  Y   X   鼀ᆠ  �ᆠ  �泐 ᨨ    矄泐矄鼀 X + Y 㡰 ᆠ矄矄 ᆠᨨ � ᨨ盐矄泐矄 Y 矄� 矄   ᨨ犨 

B

Fv

Mg

鼀ᆠ  �ᆠ �泐ᨨ  矄泐矄鼀 X졔Y㡰�矄ᆠᨨ � ᨨ盐矄泐 ᆠ矄� � ᨨ ᨨᆠᨨ鼀   �矄ᆠᨨ盐矄 ᨨᆠ矄

f  + N  = m  N  + N  = m  + ҈N

mg矄� q

Mg

R = Mg 㡰  + m + M 㡰 g 桌 ¹ Mg

鼀ᆠ  �ᆠ �泐ᨨ  矄泐矄鼀 X 졔 Y㡰�矄ᆠᨨ � ᨨ盐矄泐 ᆠ矄� �矄  矄泐矄鼀 �矄 ᆠᨨ鼀� � ᨨ犨    �矄 ᨨ �  �泐�矄 ᆠ矄� � ├� �ᆠ �泐鼀� � � 矄鼀

ᨨ⼄盐ᨨ  犨��  ᨨ Yᨨ盐 P ¹  矄㡰 ᨨᆠ ᨨ  Y 泐 X �矄 㦨 犨 ᨨ �⼄盐�  �矄ᆠ  犨 �ᆠ ᆠ

ᨨ⼄盐ᨨMg 矄   矄�泐ᨨ Y>  矄�泐ᨨ X  Y�矄矄� ├� �㡰

 ���ᨨ  ᨨ �  �泐 ᨨ  X � ᆠ矄矄 ᆠᨨ � ᨨ盐矄泐ᆠ盐矄矄 Y鼀ᨨ矄 ᨨ犨  ᆠ ᨨ 鼀矄矄 ᨨ  X 鼀ᨨ矄 盐 㡰 和 Y�矄鼀ᨨ� �犨� 鼀� ᨨᆠ�泐 

t

v

R 

ᔼ  �矄ᆠ矄  ᨨᆠ  泐Xᨨ Y㦨 ᨨᆠ  泐 Yᨨ X  ᨨᆠᨨ X 盐ᨨY�矄

r r  mbt  D㦨  ò F × dr 㦨  m ò bˆ × a�ˆ + b tˆ 㡰dt 㦨

  ҈  ҈    ⧤㦨 mv = m a + b t 㡰   ҈  꾀矄ᨨ쟼㦨⧤졔㦨 ma 㦨ᆠᨨ 矄   ҈䰘 꾀 ® 㡰 錐  ® ⼄矄㡰 錐 ᔴ ® 㡰   ® ⼄ 㡰 꾀矄   ᨨᆠ�泐�矄 ᆠᨨ 矄  f = mg 矄� q \ 盐 f = mN = mmg ᆠᨨ矄 q \ mmg ᆠᨨ矄 q = mg 矄� q  Þ  m =  q

 ᨨᆠ 泐Xᨨ  Y�矄 矄盐 ᨨ f  N

mg

Ӹ

 ҈ 

æ R - rö ÷ R ø

ᨨ ├� �ᆠ  �泐ᨨ    � � 㦨 ⧤� �ᆠᨨ�ᨨ  졔 ├� �ᆠ  �泐  矄�ᨨ 㡰 ҈ K Etᨨtal = MR  㡰w = M w  R - r 㡰   㡰 mM w鼀� R - r 㡰 = Mg g \ w鼀� = m R - r 㡰 㡰 꾀 �矄 ᨨ ᨨ�ᨨ  �矄  ᨨ 㜠 �矄  ᆠ ᨨ ᨨ   ᆠ矄矄 �  矄  ᨨ盐矄  �矄 矄矄� �  ᨨ盐�  �矄 �ᆠ 㡰 ᨨ��� ᨨ 泐w �矄 矄鼀  ᨨ  泐 ᨨ�  ᨨ   ᨨ 泐 㡰 kxf㦨Ma  a㦨Ra a kx - f é fR ù \ = Rê ú a ҈ M  ê MR ú ë û  2kx é fR ù = Rê ú ҈  f ê MR ú ë û ᆠ㡰  w R - r 㡰 = wR \ w = wᨨ çè

WWW.JEEBOOKS.IN

EBD_8341 PS-76

Physics

和ᨨ� �  �矄 ⼄盐�ᨨ  犨 � ├ ├ \  = ├ - = ├ =  

�矄 �矄 ᨨᨨ矄� ᨨ �矄ᆠ鼀   kx f =   kx \ Fnet = �ᆠ  ᨨ犨 矄   ⼄盐���盐鼀 

æ kx ö ÷x è  ø k F æ k ö x = -w  x Þ w = \ a = net = - ç è M ÷ø M M  ᆠ㡰 㝐ᆠ  �ᆠ �泐�矄ᆠᨨ 矄 � ᆠ矄ᨨ 盐ᨨ� � 鼀ᨨ�ᨨ

 ҈ é҈  ù  ҈æ҈  ö æ v ö Mv + MR \  ç ÷ ç ÷ =  ê kx 鼀 ú  è  R øè ø ë û M x鼀 = v \ k kx鼀 k M F鼀 = mMg = v =   k M v = mg \ k � b㡰 ᨨ矄矄 �  ├� �ᆠ �泐㦨 KE㡰� ��   KE㡰 �   㡰 Fnet = ҈ - ç

 é҈ é҈ æ ö ù  ҈ ù 㦨 ê I w 㡰 +  I 㡰 w ú - ê I +  I 㡰 ç w ÷ ú è ø ú  ë û êë  û



䰘



 I w 㦨  I w  - I w  =   㡰 ␔   �矄ᆠB �矄ᨨ盐�  � ᆠᨨ ᆠ 犨�  �矄ᆠ A  w  ᆠᨨ鼀鼀ᨨ  ᨨᆠ�泐 ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀 ᨨ  犨ᨨ �矄ᆠ 矄泐矄鼀  I w㡰졔I w㡰㦨 I졔I㡰wἘ Þ wἘ㦨 w 

ᨨ⼄盐 ᨨ  �矄ᆠ A  I ´ w - I ´ w DLA L f - L� - I w  = = = tA㦨 t t t t  ��矄�� � �ᆠ矄  ᨨ⼄盐ᆠ矄 �盐  �ᨨ  ᆠ㡰 ᨨ �矄ᆠ A 2w ҈  ҈ kx҈ = I w 㡰  Þ kx҈ =  I w    A ᨨ �矄ᆠ B ҈  ҈ kx = ´  I w   Þ  kx = I w w   x k x҈  I w  B Þ ҈ =  = \    x kx Iw  �矄   �  ᨨ� ᨨ  ᨨ矄��ᨨ

\ ᨨ⼄盐 ᆠ� � ᨨ    �矄 ᨨ m b⏌

F

a

b⏌

mἘ

Mg

b⏌

b b =F´  �㡰   n 盐鼀ᨨ 矄ᆠ ᨨ 鼀矄矄 m矄�├� �犨� ᨨᆠ�泐v ᨨ  矄     ᨨ�ᨨ  ᨨ    b dp F㦨 n 맔A㦨n맔 mv㡰맔a맔 Q A㦨㡰  dt 盐� � �矄盐ᨨ  � ⼄  �㡰 b b b Mg맔 㦨n맔 mv㡰맔a맔 맔    ´  Þ 맔҈㦨҈맔맔҈맔v맔҈맔  \ v㦨҈鼀⏌矄 Y 黨 和� ᆠ 矄泐矄鼀�矄� ⼄盐���盐鼀 P Mg맔

\

X

SFy㦨

mg

Mg졔mg졔MgNN 㦨

Þ Mg졔mg졔Mg㦨N졔N

N

Mg f

A

N

Mg f

B

m2

mg

M + m㡰 g Þ N㦨  �㡰     �ᆠ�ᨨ  ᨨᆠ꾀 ᔴᆠ盐� �ᨨ⼄盐矄 ᨨ盐 P Q P Mg맔PQ졔f맔PM㦨N맔OP O q Þ Mg맔

L ᆠᨨ矄 q + f ´ L 矄� q  = NL ᆠᨨ矄 q

MgL NL ᆠᨨ矄 q ᆠᨨ矄 q  Þ f㦨 L 矄� q

N A

l⏌ q f

Mg M

Mg ᆠᨨ q  éæ N + m ö Mg ù ᆠᨨ q Þ f㦨 ê ç ÷ø g è   úû ë gù é Þ f㦨 ê( M + m) ú ᆠᨨ q û ë  꾀盐ᨨ 鼀矄矄m矄�├矄 犨ᨨᨨ  ᨨ�ᨨ 鼀矄矄 M  � L 矄�ᆠ├矄ᨨ� ur ur r r dL Þ t ´ dt = d L

ᨨ⼄盐 t = dt r r ␔    �盐 �鼀盐矄 t ´ dt 㡰  �矄 ᨨ    �盐 鼀ᨨ鼀 盐鼀 �矄 ᆠᨨ 矄  ᔼ   �矄 ᆠ矄 ᨨ   犨ᨨᨨ 

ᨨ�㜠盐矄泐矄鼀  �盐�鼀盐矄ᨨ盐O�矄ᆠᨨ 矄  \ ᲼ �盐 鼀ᨨ鼀 盐鼀 ᨨ    矄泐矄鼀桌� �� 㦨 ᲼ �盐 鼀ᨨ鼀 盐鼀 ᨨ  矄泐矄鼀桌 �  Þ mv맔L㦨I맔w  �㡰 犨 I�矄 鼀ᨨ鼀 ᨨ � �ᨨ  犨ᨨᨨ  ᨨ�㜠盐 矄泐矄鼀   ᆠᨨ�矄�ᨨ  ᨨ盐 O I㦨I犨ᨨᨨ  ᨨ�졔I盐 ҈   㦨 ML + ML  ��㡰  ᨨ鼀⼄ �㡰  ��㡰 mv mv ´ L w㦨 = M + m㡰 L é҈  ù êë  ML + mL úû  = N ᆠᨨ q -

WWW.JEEBOOKS.IN

PS-77

System of Particles and Rotational Motion ҈

㡰  ᨨ�  Ἐ졠Ἐ  ᨨ   ᆠ  ᨨ 鼀矄矄 ᔴ㝐㡰 ᨨ   矄泐矄鼀 \

l 

OA㦨 r =

  + w� = + -҈㡰  ���㡰 I AB ҈ +  x  ᨨ鼀⼄ ��㡰  ���㡰  é ù - ҈ + ҈ú Q w� = ҈ᨨ ⏌矄㡰 㦨맔x ê  ҈ + x ë û  é ù ҈㦨�x ê ú ë҈ +  x  û Þ ҈졔x㦨�x᲼졔桌㦨҈�x \ x҈�x҈㦨 和ᨨ� �犨�x㦨҈ᨨ 盐x㦨鼀wfᆠᨨ鼀矄ᨨ盐ᨨ �� �ᨨ ⏌矄㡰 犨 �ᆠ  �矄 ᨨ ᆠᆠ  ᨨ 㡰 x㦨 �矄 ᆠᨨ ᔴ㝐 ᨨ鼀� 꾀㦨҈鼀 㡰 和盐矄�盐� �x㦨҈鼀� ⼄ ��㡰犨�wf㦨҈ᨨ ⏌矄   �盐 ᨨᆠ�泐犨�  犨 �ᆠ  矄  ᆠᨨ鼀矄 ᆠ├     �矄�鼀ᆠ�矄҈ ⏌矄 ᆠ㡰 꾀矄   矄  盐 矄 犨�  矄鼀  �盐 ᨨᆠ�泐ᨨ ҈ ⏌矄 矄 犨� ᆠᨨ鼀ᨨ矄

\

泐 �ᨨ鼀泐㡰 A m㡰 y x

l

l

O CM F

 l 

r

l

B m㡰

C m㡰

F㦨ᆠ � ᨨᆠᨨ  F㦨 m㡰rw

æ ҈ ö  w F = m㡰 ç è  ÷ø ᨨ F = ml w  㡰  a     �盐 ᆠᆠ�ᨨ  ᨨ  矄泐矄鼀 ᨨ盐 ᨨ�  A æ  ö F 㡰 çç l÷  ÷ø tA F è a= = =  IA ml ml ᨨ犨ᆠᆠ�ᨨ ᨨ ᔴ㝐ᨨ �x㜠 �矄�矄

ᨨ

æ l ö æ F ö ax = r a = ç ÷ ÷ç è  ø çè ml ÷ø

F ᨨ ax = m Fx  ᨨᆠ� 泐  � �ᨨ � X㜠 �矄 \ Fx 졔 F = m㡰ax  F ö ᨨ Fx + F = m㡰 æç ᨨ Fx + F = F ÷ è m ø  F  Fy  ᨨᆠ� 泐  � �ᨨ �Y㜠 �矄 \ Fy 㦨 ᆠ � ᨨᆠ ᨨ

Fx =





ᨨ Fy = ml w x  �矄 ᆠᨨ ᆠ ᨨ 鼀矄矄 ᨨ鼀� AB \ 㝐ᔼᨨ 鼀� 矄 ᨨ盐AB IAB㦨Iᆠ鼀졔mx ᨨ鼀 矄 ᨨ鼀㡰 IAB㦨҈졔x  �㡰



wf㦨

ᔼ ��泐   �矄ᆠ �矄  �ᆠ犨�  ᨨ� A�矄 �� 矄 ᨨ矄��ᨨ  ᔼ 矄矄 ᨨ� �犨   ᨨ犨 ᨨ   ᆠ �矄 ᨨ �  �泐 ᆠ  �矄 ᨨ ᨨ�ᨨ  ├� �ᆠ  �泐

A m R C

꾀泐� �  �泐 ᆠᨨ 矄�ᨨ



P

ᆠ鼀

B m㦨├�

IAB wfw�㡰㦨맔�㦨

R

  ᆠ  ᨨ쟼

R ö R ö ҈ æ æ + mg ç R + = mgR + I w  ÷ ÷ è è  ø  ø  ␔ I㦨 MI ᨨ  �矄ᆠ㜠鼀矄矄矄泐矄鼀ᨨ盐PQ ҈  ҈ R R ҈ + mg = mgR + I w   Þ mgR㦨 I w mg맔     mgR I  I㡰PQ㦨 I �矄ᆠ㡰PQ졔 I鼀矄矄㡰PQ

Þ w㦨

 �㡰

  é mR  æ Rö ù æ �R ö ê + M ú + m 㦨 çè ÷ø çè ÷ø  ûú  ëê 

҈ MR  桌 

mR  ᲼ + ҈ + �桌 ҈�mR  = ҈  盐� � �矄盐ᨨ I� ⼄ �㡰 ᔼ㦨

mgR ´ 

҈ g �R ҈�mR

 �  矄  ᨨ    �ᆠ 矄 � ᆠ 矄 �矄 ᨨ犨矄 ᨨ矄��ᨨ

w㦨

ᆠ盐矄 ᨨ �鼀盐矄    �盐 ᨨᆠ�泐 ᨨ   鼀�  矄  犨� ᆠ  �   泐�鼀ᆠ ᔼ鼀盐矄㦨ᆠ  �� � 鼀ᨨ鼀 盐鼀 㦨 Vf V�㡰 㦨맔x wfw�㡰  ��㡰 꾀矄ᨨᆠ  ��  �盐鼀ᨨ鼀 盐鼀㦨鼀ᨨ鼀 ᨨ �鼀盐矄 \ IABwfIABw�㦨ᔼ鼀盐矄맔 �矄 ᆠ

ᔴἘ

mg ç  R +

᲼Q MIᨨ  �矄ᆠᨨ盐 �鼀㦨 x

Q

R⏌

v

쟼 �� �泐㦨 �  �泐

A

鼀 �

R/4

P



=

҈ g �R Rö æ ´ = � gR \v㦨 ÷ �R  è ø  㡰 ᆠᨨ�矄�ᨨ �矄 矄�ᆠ  矄 �矄 �    ᆠ   犨 � 犨� 盐  ᆠ├ 犨�    矄鼀 ᨨᆠ�泐 �  鼀� �盐 㡰 v㦨w ç R +

WWW.JEEBOOKS.IN

EBD_8341 PS-78

Physics Z

Y

꾀矄ᨨ

X

\ 

F  

t fR f f = = = = ҈ f I mR  ⏌  mR  ´ ҈ a㦨҈f  ��㡰 m ├� ├� z a=

 ᨨᆠ矄ᨨ 矄� ᨨᆠ  � ᨨᆠ�泐ᨨ  犨 � � X㜠 �ᆠ�ᨨ �矄Fx Fx맔Dt㦨mv mv㡰 ᔼ鼀盐矄㡰㦨 ᔴ  �� 鼀ᨨ鼀 盐鼀㡰

҈鼀 O y

 mv  mv  mv Þ F㦨  Þ Fᆠᨨ矄 㦨 Dt  Dt Dt Q Fx㦨Fᆠᨨ矄  Fy㦨F矄�  ᔼ  ᆠᨨ 鼀矄 ur F 㦨 Fx $� + Fy - k$ 㡰 = F ᆠᨨ矄°�$ + F 矄� ° -k$ 㡰

\

Þ

f

ᨨ

$ ҈ � + F ´ - k$ 㡰  

mv F + mg = + mg  Dt

�

mv Dt

ᨨ ᨨ ᨨ

 � ᨨ ᨨ 㦨ᆠ鼀㦨鼀

\

a 

ᨨ f =

(

) ( )

r t҈ = -҈ ˆ - ҈kˆ ´ �ˆ N - m

r t҈ = kˆ -  ˆ r t҈ =  kˆ - ˆ 㡰 N - m

 �㡰

ᨨ

(

)

t  =  - ˆ - kˆ 㜠鼀

r  t   = 㡰  + 㡰 =  ´  = � 㜠鼀 r r  t҈  =  t   = � 㜠鼀

 �盐矄ᨨ ᆠ  �矄ᆠ㦨R㦨҈ᆠ鼀㦨҈鼀

a㦨� ᆠᆠ�ᨨ ᨨ ᆠ ᨨ 鼀矄矄ᨨ  �矄ᆠ a 㦨  �盐 ᆠᆠ�ᨨ  ᨨ盐 �矄 ᆠ ᨨ 鼀矄矄 f f a = =  �㡰 m 

ᨨ f =

r r r 和�鼀�泐 t = r ´ f

෌� 㝐矄矄ᨨ ᆠ  �矄ᆠm㦨├�

�㡰

f =a 

㦨�㜠鼀

 �矄ᆠ㜠ᨨ 矄泐矄鼀ᆠ ᨨᨨ  盐ᆠ├犨� ᨨ盐矄�� � 矄   �ᆠ�ᨨ  ᨨ   �矄ᆠ㜠ᨨ  矄泐矄鼀 犨�   ᨨᨨ ᨨ   鼀ᨨ� �盐ᆠ├�矄�

 �矄ᨨ  �矄ᆠ㜠ᨨ ᨨᆠ�矄 ᨨ� ᨨ   �ᆠ盐 ᨨ  �ᆠ�ᨨ ᨨ  鼀ᨨ�ᨨ ᨨ 盐ᆠ├z㜠 �矄�矄 �ᆠ泐 盐犨  �ᆠ�ᨨ 

fö ÷ 졔 ҈㡰 ҈f 㡰㦨 ᨨ鼀 �㡰㡰 ø

r  t҈  = 㡰  + 㡰 =  ´  = ҈҈ ´ 

´h

꾀ᆠᆠ�ᨨ ᨨ 盐ᆠ├ᨨ �x㜠 �矄㦨 黨鼀⏌矄

æ çè

��㡰 �ᆠ�ᨨ  ᨨ⼄盐 t = r ´ f r 꾀  P r҈ = ҈ ˆ - ҈kˆ r 꾀  Q r = ҈ ˆ - ҈kˆ r r r \ t҈ = r҈ ´ f

æ mv ö + mg ÷ k$ N㦨 ç è D t ø

�矄�矄  ᨨ鼀 ᨨᆠ  泐 ᨨ  犨 � 盐� � �鼀D b㡰 ᨨ⼄盐矄 ᨨ  犨 � ᨨ盐   ᆠ  ᨨ  鼀矄矄 ᨨ    犨 � F맔h ᨨ⼄盐 盐ᨨN졔mg맔㦨 h�矄  �ᆠ盐 �矄 ᆠ犨  ᆠ ᨨ 鼀矄矄ᨨ  犨 �   � ᨨ ᆠ�ᨨ ᨨ 

ᨨ⼄盐 盐ᨨN㦨F맔h㦨

f

 ´ 黨 = N 

�矄 ᨨᆠᨨ  �ᆠ�ᨨ  f�矄 ᆠ� �� ᨨ矄��x㜠 �ᆠ�ᨨ  �ˆ �矄 盐 �ᆠᨨᨨ � x㜠 �矄 r \ ᔼ  ᆠᨨ ᨨ鼀 f = �ˆ㡰  犨ᨨ

 ���㡰 ᨨ

쟼⼄盐���盐鼀ᨨ  ᨨᆠ� Z㜠 �ᆠ�ᨨ  ᆠ� �ᨨ 犨 �㡰 Fy졔mg㦨N

\

Q

和� ᆠ   �矄 ᨨ 矄�� � 犨  �矄ᆠ   盐ᆠ├ ᆠᆠ�ᨨ  ᨨ P㦨 ᆠᆠ�ᨨ  ᨨ Q a졔Ra㦨a

ur F mv  $� - k$ 㡰 F 㦨  $� - k$ 㡰 =  Dt

Þ N㦨



P

Fx㦨

㦨F맔

҈鼀



㡰 ᆠ泐� ᨨ  �盐矄 鼀矄矄ἘmἘᨨ矄ᨨ   �ᨨ  ᆠ �盐 ᨨᆠ├犨� ᨨ盐矄�� � ᨨ�ᨨ  ᨨ   ᆠ泐�  �矄 ᨨ盐   ᨨ�  ᨨ  ᆠᨨ ᆠ 矄ᨨ  �泐 ᨨ    ᆠ泐�  �矄 ᆠᨨ 矄     ᨨ���  ᨨ矄��ᨨ  ᨨ ᆠ  ᨨ 鼀矄矄 ᨨ   ᆠ泐�  O␔ �ᨨ� � ᨨ犨 ᨨ   � ᆠ泐�  矄盐ᆠ ᨨ矄��ᨨ  �矄ᆠ ᨨ 鼀矄矄�矄ᨨ矄��ᨨ OἘ ÐNPO q 꾀矄 ᆠ泐� �矄ᨨ� � ᆠ鼀ᨨ矄

WWW.JEEBOOKS.IN

PS-79

System of Particles and Rotational Motion �   ᆠ�ᆠ盐    ᆠ � ᨨᆠ ⼄盐�  ᨨ   ᆠ�ᆠ盐 鼀ᨨ�ᨨ  N



҈ ҈ ҈  æ g ö  mgR 㦨 ´ mR ´ ç ÷ +  m v Ἐc 㡰 R   䰘 è ø

O

mvc mgᆠᨨ矄 q N㦨  R

 ᆠᨨ ��ᨨ  ᨨ   ᆠ泐�  � �    � N㦨

R

h M Rh

w q os

gc

m

q

OἘ

q R mg P

mg矄� q

vc mvc  Þ ᆠᨨ矄 q 㦨  �㡰 Rg R 꾀泐� �  �泐ᆠᨨ 矄�ᨨ  ᨨ鼀 O ᨨ OἘ ᨨ矄矄 ᨨ  ᨨ �  �泐ᨨ ᆠ泐�  㦨�� �  矄�ᨨ KE졔�� � ᨨ�ᨨ KE

\

vc  gR ⏌ 䰘 = R R mgR  mgR Þ mgR 㦨 㦨 矄�ᨨ KE 䰘 䰘 ҈  mgR 꾀矄ᨨᨨ�ᨨ  KE㦨 Iw =  䰘

 矄�ᨨ  K E = \ ᨨ�ᨨ  K E  w㦨

Q

vc

mgᆠᨨ矄 q 㦨

҈  ҈  mgh㦨 mvc + I w  ��㡰   ␔ I�矄  鼀ᨨ鼀 ᨨ � �ᨨ  ᆠ泐� ᨨ盐OἘ ҈ I = mR  , w �矄    �盐 矄  Vc �矄   ᨨᆠ�泐 ᨨ  ᆠ  ᨨ  鼀矄矄

dL 䰘 和� ᆠt㦨  t㦨 dt

P

\ L �矄 ᆠᨨ 矄 

꾀 �盐鼀ᨨ鼀 盐鼀 ᨨᆠᨨ�矄�ᨨ 㦨mv맔 l l 꾀 �盐鼀ᨨ鼀 盐鼀 ᆠᨨ�矄�ᨨ 㦨Iw I㦨Im졔I꾀졔I

vc R 盐� �盐ᨨ I w� ⼄  ��㡰

m 㦨�├�㡰

é ì æ l  ö æ l ö ï ìï æ l ö æ l ö  üï ù  ï ê m  l 㡰 + 㦨 í mA ç ÷ + ç ÷ ý + í mB ç ÷ + ç + l÷ ý ú è  ø ï ï è ҈ ø è  ø ï ú ҈ êë îï è ø þ î þû ü

mgh 㦨

é æ l  l ö æ l  黨l  ö ù  + ÷ + mB ç + 㦨 ê  ml + m A ç ÷ú  ø úû êë è ҈  ø è ҈

é ë

 ���㡰

 gr ҈ - ᆠᨨ矄 q㡰 Rg

 䰘 b㡰 和 ᨨ ᔴ㝐ᨨ ᆠ泐�  ᨨ� �ᆠᨨ ᆠ犨�  �

 gR  gR æ  ö  gR ᲼ ᨨ鼀 ���㡰桌  Þ vc㦨 ç҈ - ÷ = 䰘  è 䰘ø 䰘 ᆠ㡰  ᨨ ᆠ ᨨ 鼀矄矄 ᨨ  ᆠ泐�  ᆠ 矄   ᨨ� ᨨ � ᨨ   ��矄 ᆠᨨ ᆠ犨�    �  q = ᆠᨨ矄 -҈ = ��҈�° 䰘  ᆠ   ᨨ�ᨨ  K.E 犨 �ᆠ   ᆠ泐� �� 矄    �鼀ᨨ � �ᆠᨨ ᆠ犨�   �鼀� 矄 矄鼀� �矄 盐 鼀ᨨ�ᨨ    ᆠ泐� �� 矄 矄�ᨨ K.E 꾀��  泐� �  �泐 ᆠᨨ 矄�ᨨ  ᨨ鼀 O ᨨ   ᨨ�  犨 ᆠ ᨨ 鼀矄矄�矄 �  ᨨ� ᨨ � 犨�  � ҈  ҈  mgR㦨 I w + m v Ἐc 㡰  

䰘 ù m l  = 黨 ├� m  B úû

Iw㦨mv맔 l

mv ´ l � ´ v ´  ´  = 㦨䰘v 黨 I 꾀泐� �ᆠᨨ 矄�ᨨ  ᨨ 鼀ᆠ  �ᆠ �泐  ᆠᨨ�矄�ᨨ  ᨨ矄矄ᨨ KE㦨�� � PE Þ w㦨

҈  æ lö æ l ö I w = mg l㡰 + m A ç ÷ g + mB g ç ÷ è ø è ø 

Þ ᆠᨨ矄 q 㦨ᆠᨨ矄 q  Þ ᆠᨨ矄 q 㦨

vc =

҈ 

㦨 ê ml + m A l +

ᨨ鼀⼄ �㡰  ���㡰犨�

ᆠᨨ矄 q =

mB B

v

꾀矄ᨨ ᨨᨨ� �vc㦨wR Þ w㦨

v ҈  ҈ ҈ mvc + ´ mR  ´ c    R ҈  ҈     gh  Þ gh㦨 vc + vc = vc  Þ vc =     R-h ᔼ DO¢MP ᆠᨨ矄 q = R Þ h㦨R ҈ᆠᨨ矄 q 㡰 g  R ҈ - ᆠᨨ矄 q㡰 \ vc = 

mA A

҈ ´ 黨 ´ 䰘 v㡰   ҈ ù é 㦨 ê � ´  + ҈ ´ +  ´ ú ´ 黨 ´   û ë Y Þ v㦨鼀⏌矄 R T w  �㡰 꾀ᆠᆠᨨ � � ᨨ M ⼄盐矄�ᨨ    盐鼀 �矄 m T ��    � ��  �盐 X ᨨᆠ�泐 矄盐ᆠ      q ᨨᆠ├ X 矄矄 鼀ᨨ� � 盐 mg矄� q mg mg ᆠᨨ矄q     Þ

q=30 o

꾀矄  �鼀矄矄矄   ᨨᆠ├ X �矄矄 盐   ᨨᆠ�泐 ᨨ   ᨨᆠ├ ᆠ矄矄a �  �ᨨ ᨨ  ᨨᆠ├X. \ mg 矄� q - T = ma  �㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-80

Physics

 �   �ᨨ  ᨨ    ᨨᆠ├ a      �盐 ᆠᆠ�ᨨ ᨨ   盐鼀 a㡰  矄

a R 犨 R�矄  �盐矄ᨨ   盐鼀

 � �ᨨ⼄盐ᨨ   盐鼀�矄 盐ᨨ 矄�ᨨ T�   矄� � t㦨T맔R㦨Ia Q t㦨Ia㡰 a㦨 a Þ a =

\

҈  T맔R㦨 MR a 

҈ é ù êëQ I =  MR úû

a T ҈ MR  Þ a㦨  R M 和盐矄�盐� � �矄 盐ᨨ � ⼄ �㡰

Þ TR㦨

mg矄� q T㦨m맔

T æ m ö Þ mg矄� q 㦨 ç҈ + ÷T è Mø M

mg 矄� q㡰 ´ M � ´ 黨 ´ 矄� ° ´  = 㦨҈ M + m  +  ´ � ��㡰 �矄 ᆠ   泐x

\

T㦨

T  ´ ҈ = = ҈ m ⏌ s  M  盐矄� �V㦨RwÞ V 㦨맔҈㦨鼀⏌矄 Q R㦨m w㦨҈ᨨ ⏌矄�� 㡰 \ �矄 ᆠ   泐 ᨨᆠ├ x

a=

´ v = a  ´ ҈ \ �矄 ᆠ 泐x㦨҈鼀 㡰 꾀 �盐鼀ᨨ鼀 盐鼀ᨨ  矄泐矄鼀 ᨨ 졔� 矄ᆠ㡰ᨨ盐  ᆠ ᨨ 鼀矄矄Ἐ졠Ἐ ᨨᆠᨨ�矄�ᨨ 㦨 �盐鼀ᨨ鼀 盐鼀 ᨨ    矄泐矄鼀   ᆠᨨ�矄�ᨨ  L M Mv맔 = I w  v ␔  I �矄   鼀ᨨ鼀  ᨨ � � ᨨ    矄泐矄鼀 盐矄 ᆠᨨ�矄�ᨨ  w A B O �矄    �盐 ᨨᆠ�泐 L⏌ L⏌ 盐矄   ᆠᨨ�矄�ᨨ  as㦨盐Þ s =

黨

Þ

Þ

Mv

 ù L é æ Lö ҈ = ê M ç ÷ + ML ú w  êë è  ø ҈ úû

L ML é ҈ ҈ ù ML é  +  ù Mv ´ = + úw= ê   ë  û  êë ҈ úû 

҈ v 䰘 ML  ´ ´ w  Þ w㦨 䰘 L  ҈ b㡰 꾀 ᆠᨨ�矄�ᨨ  �矄    鼀矄矄Mᨨ  � 矄ᆠ 犨 �ᆠ ᆠ矄  ᨨ⼄盐 �   ᆠᨨᆠ├犨�矄  �ᆠ�ᨨ  犨 �ᆠ  矄 ᨨ ᆠ  �盐 ᆠᆠ�ᨨ  �    ᨨ  盐   矄鼀 �矄 ᆠᨨ鼀 矄  泐   鼀ᨨ鼀  ᨨ � 矄ᆠ ᨨ犨 矄 B 盐ᨨ犨 �ᆠ 鼀ᨨ鼀 ᨨ � �Iᨨ  矄泐矄鼀� ᆠ矄矄    泐 � 矄  ᨨ  �鼀 t   � 矄ᆠ    �矄 ᆠ x 㦨

ᨨ鼀  ᆠ  ᨨ  ᨨ     ᨨ  矄 盐    ᨨ盐�   � q 㦨wt㡰犨�矄ᨨ��� ᨨ矄��ᨨ

dL d A = I w㡰 㦨 dt dt M

dI = w dt 㦨 w

A

q =w t

O x

d é҈ ù ML + Mx  ú ê dt ë҈ û

B N B

dx Mg dt

�矄 ᨨ⼄盐 �矄  ᆠ  泐   ᨨ⼄盐 盐 ᨨ 犨��  ᨨ � 矄ᆠ dx æ g ö ᆠᨨ矄 wt dt \ Mwx 㦨Mg xᆠᨨ矄q㡰 Þ dx㦨 ç è w ÷ø dt 졠 � ��ᨨ ├� ��鼀�矄 L⏌ g p ⏌ w ò L ⏌  dx = w ò  ᆠᨨ矄 wt dt L 犨 

x =  wt =   L⏌ g p ⏌ w [ x] L ⏌  =  [ 矄� wt ]  w p L 犨 

x㦨  wt =   g é p æ L Lö ù Þ ç - ÷= 矄� - 矄� ú è   ø w  êë  û 㦨Mwx

Þ

L g g =  Þ w㦨 L  w 

盐 w㦨

҈ v ҈ v = Þ 䰘 L 䰘 L

g 䰘  gL Þ v㦨 L ҈

䰘  ´ ҈ ´ ҈ 㦨�鼀矄҈ ҈   ᨨ ᆠᨨ�矄�ᨨ   ⧤� �ᆠ  �泐ᨨ   矄泐矄鼀 ҈  ҈  ҈  ⧤쟼� 㦨 m҈v҈ + m v + MV    ҈  ҈   �㡰 㦨  ´ ҈ +  ´  +  = �    Þ v㦨

M 㦨҈├� ҈鼀⏌矄

A

m҈ 㦨├�㡰

x = �鼀 C x = �鼀

m

鼀⏌矄 㦨├�㡰

B

꾀泐� � 犨 ᨨ ᆠᨨ 矄�ᨨ  ᨨ �  鼀ᨨ鼀 盐鼀 盐� � ᆠᨨ�矄�ᨨ

m҈맔v҈졔m맔v㦨 M졔m҈졔m㡰Vc 犨  Vc �矄   ᨨᆠ�泐 ᨨ ᆠ  ᨨ 鼀矄矄 ᨨ     �ᆠ矄 矄�ᆠ├  ᨨ  �   ᆠᨨ�矄�ᨨ

맔҈졔맔㦨 ҈졔졔㡰Vc Þ Vc㦨鼀⏌矄

WWW.JEEBOOKS.IN

PS-81

System of Particles and Rotational Motion \

⧤쟼 矄 ᆠᨨ�矄�ᨨ

҈  㦨 M + m҈ + m 㡰Vc = �   ��㡰  꾀泐� � ᆠᨨ 矄�ᨨ  ᨨ   �盐 鼀ᨨ鼀 盐鼀 ᨨ       犨ᨨ �ᆠ 矄泐矄鼀 ᨨ盐  ᆠ  ᨨ    TExternal㦨 \ L㦨ᆠᨨ 矄  L � 㦨m҈v҈맔xmvx 㦨맔҈맔�맔맔� 㦨㦨҈├�鼀矄҈ ᔼ  ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ 㡰 Lf㦨Iw

\

҈

҈  ҈  ⧤쟼 ᨨ㦨 I w = ´  ´  = ҈   �㡰   K.E.f 㦨  矄�ᨨ KE졔 ᨨ�ᨨ KE 㦨�졔҈㦨䰘 D KE㦨KE� � KEf 㦨�䰘㦨䰘 PED㦨PEQ졔 KE㡰Trans졔 KE㡰Rᨨt ᨨ鼀  �泐ᆠᨨ 矄�ᨨ  � ᆠ� ҈  ҈  Þ mg 㡰㦨mg ҈㡰졔 mv + I w   ҈  ҈ æ   ö v mv + ç mr ÷  ør  è� vö   æ çèQ I = mr  w = ÷ø � r

䰘v  ᨨ g ´ ҈ = Þv㦨鼀⏌矄 ҈ 꾀 ᨨ� Q    ᨨ   D ᨨ 泐ᨨ�ᆠ ҈  Q 鼀⏌矄 鼀 h㦨 gt Þ҈㦨黨 t y  ҈鼀 ҈ �矄ᆠ = \ ty㦨 B C A 黨 �矄 ᆠ矄BC㦨V맔ty㦨맔�㦨鼀 盐� � �矄 ��  矄  ᨨᆠ�   矄  ᆠᨨ � 盐矄 ᨨ ᨨ ᆠ盐矄 ᨨ ᆠᨨ 矄�ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀 矄鼀鼀矄矄m鼀ᨨ矄ᨨ盐 ᆠ�ᆠ盐 ᨨ  �盐矄r  矄� �鼀├矄  �q犨�  �ᆠ T     矄�ᨨ

Tᆠᨨ矄 q 㦨mg �㡰 T矄� q 㦨mrw ��㡰 l \

 q 㦨

q

r w g

ᨨ鼀 ��盐矄� q 㦨

Þ r㦨 l 矄� q

T

r  l

r

q

T ᆠᨨ矄q

T矄� q mg

 q 㦨 l 矄� q

 Þ w =

w g

 qg ᨨ w = l 矄� q

g l ᆠᨨ矄 q

g ҈  ���㡰 Q w = pn p l ᆠᨨ矄 q ᨨMᨨ鼀� 矄�ᨨ 泐T㦨Mg  Tᆠᨨ矄q㦨mg \ Mg ᆠᨨ矄 q 㦨 mg m Þ ᆠᨨ矄 q 㦨 M 盐� � �矄盐ᨨ ᆠᨨ矄q�矄⼄ ���㡰犨� Þ n㦨

é M l ù + m҈ x  + m x  ú w 㦨 ê ëê ҈ ûú é ҈㡰 㡰 ù +  ´ �㡰 + 㡰 �㡰  ú w 㦨 ê ҈ êë úû 㦨w w㦨҈ Þ w㦨 ⏌矄  ���㡰

mg (  - ҈) =



\

n㦨

҈ p

gM l m



O

OM ᔼ DOPMᆠᨨ矄 q =  l Þ OM㦨 l ᆠᨨ矄 q OM Ἐ ᔼ DOPἘMἘ ᆠᨨ矄 q = l Þ OMἘ㦨 l ᆠᨨ矄q

q0

q

T

㝐 㝐Ἐ

P P'

  ᆠ mg矄� q  ᨨ쟼

q mg 鼀�ᆠᨨ矄 q

OMἘOM 㦨 l ᆠᨨ矄 q - ᆠᨨ矄 q 㡰 ᨨ矄矄 �  ᨨ �  �泐㦨 ෌�  �  ├� �ᆠ �泐 꾀ᆠ��泐P ᨨ PἘ㡰 ҈  Þ mg l ᆠᨨ矄 q - ᆠᨨ矄 q 㡰 = mv  Þ v㦨  g l ᆠᨨ矄 q - ᆠᨨ矄 q  㡰  �㡰 Tmgᆠᨨ矄 q 㦨

mv  l

mv  + mg ᆠᨨ矄 q \ T㦨  ��㡰 l ᨨ鼀� �㡰  ��㡰 m T㦨 ´  g l ᆠᨨ矄 q - ᆠᨨ矄 q 㡰 + mg ᆠᨨ矄 q l \ T㦨mgᆠᨨ矄 q mgᆠᨨ矄 q Þ T㦨mg ᆠᨨ矄 q ᆠᨨ矄 q 㡰 ᨨ鼀 ⼄盐�ᨨ  ��㡰� �矄 ᆠ     矄�ᨨ  �矄 鼀 �鼀盐鼀 犨  ᆠᨨ矄 q 㦨҈� q 㦨  ᆠT鼀 㦨

mv  + mg l

ᨨ鼀⼄  �㡰 v㦨  g l ҈ - ᆠᨨ矄 q 㡰 ᨨ鼀 ���㡰  �㡰 m T鼀 㦨 ᲼ g l ҈ - ᆠᨨ矄 q 㡰桌 + mg l \ T鼀 㦨mgmg ᆠᨨ矄 q 㦨맔맔 ᆠᨨ矄 q

 ���㡰  �㡰

҈ Þ  ᆠᨨ矄 q 㦨 Þ ᆠᨨ矄 q 㦨  Þ q = ° 

WWW.JEEBOOKS.IN

EBD_8341 PS-82

Physics

Gravitation

7

v

Topic-1 : Kepler’s Laws of Planetary Motion ҈



꾀  꾀 ҈  q ҈  ҈  =   꾀㦨  q Þ 㦨  w       꾀矄ᨨ㦨鼀㦨鼀 w 꾀 ҈  \ =   鼀 ᆠ㡰 ᨨ �矄ᆠ 㦨 �   ᨨ ᆠ 졔 和ᆠ和㡰 꾀ᨨ 和ᆠ和㦨 졔   꾀ᨨ   �矄졔꾀ᨨ � �㡰 ᆠ  



 = 꾀ᨨ 和 ᆠ和㦨  꾀 ᨨ 和ᆠ和  ⏌  㦨 㦨 ⏌ 꾀ᨨ 和 ᆠ和



 ҈ 

\

v҈㦨

҈

RA RB

v - v҈ ҈ ´ ҈ ´ � ⏌҈ 㦨 㦨맔҈ ⏌矄 R - R҈  ´ ҈ ´ ҈

㡰 ෌� l㦨 꾀졔 㡰

├� �矄鼀鼀  鼀ᨨ  �   �矄 ᆠ ᨨ鼀 㦨 㦨 矄ᨨ 鼀㦨l 鼀㦨 꾀졔 㡰

R 

mV  㦨 mRw ���ᨨ  ᨨᆠᨨ ᆠ�ᨨ

R mRw㦨GMmR�⏌



  +  ෌鼀 꾀 +   㡰 







෌鼀 鼀

Þ = ò

R = ҈ T R

R T = ҈ Þ R = R҈ ´  T R T҈

R

pR p㡰  ´҈ 㡰 = = p´ ҈ ├鼀⏌ T 

=

MA

T҈

T҈



Topic-2 : Newton’s Universal Law of Gravitation



 Þ mR ´ p = GMm  Þ TµR䰘⏌ T R� ⏌  �㡰 꾀ᆠᆠᨨ � � ᨨ⧤Ἐ矄  �  犨 ᨨ  泐鼀ᨨ�ᨨ 

µ 

\

㦨



⏌ 



S҈ P

 ᆠ 矄  ᨨ 矄� S犨 S҈ 㦨vv҈㦨p맔҈p맔҈㦨p맔҈├鼀⏌ ��㡰 꾀 �盐矄 ᨨ S犨 S҈

⏌  æ R ö é R ⏌ù = ҈黨 泐矄 ÷ 㦨� ê Þ T㦨T҈ ç ú ë R û è R҈ ø b㡰 ᆠ � ᨨᆠ�矄ᨨ�  泐ᔴ � ᨨᆠ

㦨

S



pR҈ p´҈ = = p´ ҈ ├鼀⏌ T҈ ҈ v =

T҈㦨� 泐矄錐T㦨䁸錐 R҈㦨R  R㦨

�

´

�  矄  ᨨ 矄� S



҈ 㦨  ᨨ 㦨 ҈   㡰 ᔼ ᆠ矄 ᨨ  � 泐 矄 矄泐矄鼀   ���ᨨ  ᨨᆠ ᨨ  ᆠ�ᨨ

犨    矄矄 犨� ᨨ�    MB

ᆠ矄矄泐 ᆠ � ᨨᆠ矄 和ᨨ  �盐 ᨨᆠ�泐 w ᨨ  ᨨ  矄矄 �矄 矄鼀  ᨨ�鼀�ᨨ T p 㦨 鼀� 矄 矄鼀 w b㡰 꾀ᆠᆠᨨ � �ᨨ⧤Ἐ矄犨T µR

( )

R = ҈



=  ´ ҈҈ ҈ Þ R㦨맔҈├鼀 �  矄  ᨨ 矄� S҈

ᆠ㡰 꾀 ᨨᆠ�泐錐





Þ

 



+ é æ҈ ù ҈ ö é 꾀 ù = ෌鼀 ê 꾀 ç = ෌鼀 ê - +  ú ÷ +  ú ë û ë è   + ø û 㡰 꾀矄 犨├ ᨨ犨 ෌��ᨨ  ᨨᆠᨨ ᆠ�ᨨ  ෌㝐鼀 =  ෌㝐  鼀 ෌㝐  㝐 矄 ҈ =   =  ҈ 

D ҈ =

෌㝐  鼀 ҈

D҈  D  =

෌㝐  㝐 矄 

D

æ 鼀 ö æ  ö æ D҈ ö D ҈ 鼀D҈  =  =ç ÷ ÷ç ÷ç D  ҈ 㝐矄 D è 㝐矄 ø è ҈ ø è D ø  矄� �D҈㦨D㦨  錐鼀㦨맔҈ ├�錐 㝐矄㦨맔҈├� ҈㦨맔҈├鼀 㦨҈�맔҈├鼀 

D ҈ æ  ´ ҈ ö æ ҈� ´ ҈ ö =ç ÷ç ÷ ´҈ @  D  è  ´ ҈ ø è  ´ ҈ ø

WWW.JEEBOOKS.IN

PS-83

Gravitation 

 F ᆠᨨ矄 �° + F ¢ =



␔  F =  F ¢ =

GM 

 R㡰 GM

R  ´ GM 

Þ



㝐 



Mv   ᨨ鼀 ��盐㡰 R

 



R + h㡰  G 㦨 ���ᨨ  ᆠᨨ 矄  M㦨鼀矄矄ᨨ 

 ᆠᆠ�ᨨ  盐 ᨨ ��泐   h �矄





+

GM 

=

Mv  R

GM æ ç҈ R è ෌� g㦨g' gἘ =





 R 㡰  R  GM  é ҈ ҈ ù  + ú = Mv R êë  û

Þ

\

GM æ  +  ö ҈ GM ҈ +   㡰 ç ÷= R çè   ÷ø  R 㡰 ᨨ盐鼀ᨨ 鼀ᨨ  矄  

 æRö  æ ҈ö ÷ = pR ç ÷  èø  è ø

V鼀ᨨ㦨 p ç

   æ҈ö æ䰘ö    èø èø

 ᨨ 鼀矄矄 ᨨ  矄  ᆠ    鼀� � � 矄  ҈ 䰘   矄ᆠ�泐 㝐   㝐  

 ᨨ ���ᨨ  ᨨᆠ 犨   矄 犨ᨨ 矄  䰘M ҈ GM m G  ´  M ҈ ෌M  䰘 GM  ; F㦨 㦨 =    r  ´ 黨 R  R 㡰

Topic-3 : Acceleration due to Gravity





�



  g d =

GM R - d 㡰 

R Rö æ çè R + ÷ø  GM GM R - d 㡰  R - d 㡰 = Þ =   黨 R R æ R ö çè ÷ø  Þ  R = 黨 R - 黨d Þ � R = 黨 d d � \ = R 黨 b㡰 盐ᨨ g⼄盐ᨨ g A = g × - Rw 盐ᨨ  g ��  h ᨨ ᨨ

㡰 ␔�� ᨨw㦨mg㦨҈黨N Þ m㦨҈黨├� ␔�� ⼄盐ᨨw㦨mg㦨m gwR㡰  é ù æ p ö p ö = ҈黨 ê҈  ç ´  ´ ҈ ú   æçQ w = ÷ ÷ è ø  ´  è T ø êë úû 㦨҈黨᲼҈桌㦨҈黨�N We mge 黨 ge 黨 㡰 W = mg =  ᨨ g =  p p p

GM ⏌ R 

b㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  gh = g d = g҈

GM

GM æ hö ç҈ - ÷ R è R ø

- R ± R  +  ҈㡰 R  - R + �R � - ҈㡰 = R  =  

   V鼀� 㦨 pR - pR ç ÷ 㦨 pR ç ÷

gh =

=

Þh=

ᨨ盐鼀ᨨ  矄  鼀� � �㡰

҈

GM R + h㡰

hö ÷ Rø

\ R = R + h㡰 R - h㡰 = R + h + hR 㡰 R - h㡰 Þ R  = R + h R + hR  - R  h - h - h  R Þ h + h   R - R 㡰 - R  h =  Þ h + h R - R  h =  Þ h  + hR - R  = 

\ v=



GM

g=







ᆠ㡰 ᆠᆠ�ᨨ  盐ᨨ��泐 ��  h �矄 ��

泐

ᨨ

h㦨 R/ d

G M ⏌ 黨㡰 ⏌

\ Rp= R㜠d㡰

æ h ö gB = g × ç҈ - ÷ Rø è 꾀矄 ᨨᆠ �矄 犨��   ⼄盐泐    ⼄盐ᨨ   ᨨ矄 � 鼀 矄g �矄 矄鼀 矄ᆠ矄 g A = gB

R w æ h ö  gh Þh= Þ g - Rw = g ç҈ - ÷ Þ Rw = g Rø è R



R p

㡰 ෌�

꾀ᆠᆠ�ᨨ  盐ᨨ ��泐  ��   ᨨ鼀  矄 矄盐 ᆠ �矄

æ ö = ç҈ ÷  è ø

҈

= 



黨 

R 

æ ö � = � ç҈ + ÷ è  ø

䰘

=

(

-

æ ö Þ 黨 = 黨 ç҈ + ÷ è  ø

-

᲼矄  桌

)

 -҈

㦨맔҈├鼀㦨맔҈鼀 㡰 ␔� ᨨ�ᨨ ᨨ  ᨨ�盐 ᆠᆠ�ᨨ  盐ᨨ ��泐泐矄�Ἐ㦨�w ᆠᨨ矄f ␔ f�矄�盐  犨� ᨨᆠ  �� ��泐 ᨨ矄矄f 㦨黨 꾀  ᨨ  ᨨ� 矄 矄 w � ᆠ矄矄 �Ἐ 犨� ᆠ矄矄  ᆠ 犨��  ␔ 㦨 鼀� ᆠ矄矄 b㡰 ��ᨨ  ᨨ  ᆠᆠ�ᨨ  盐 ᨨ ��泐 g 犨� �矄 ᆠ Ἐd Ἐ ᨨ鼀 ᆠ  ᨨ    

WWW.JEEBOOKS.IN

EBD_8341 PS-84

Physics

ᔼ  d < R g = ᔼ d㦨Rgs㦨

Gm R Gm

҈

R Gm

҈

Þ

Q

g㦨

҈a  x㡰 ҈a

GMm G ҈M 㡰m GMm G ҈M 㡰m + KE = a a a a é ҈ ҈ ҈ ҈ ù KE = GMm ê + ë a a a a úû

-

é҈ +  -  - ҈ ù Þ KE = GMm ê úû a ë ҈ 黨GM é � ù Þ mv  = GMm ê ú Þ v = a   a ë û

Rp � Rp

 �GM  a 㡰 ෌� ෌��ᨨ  �  Ax  V¥ =  EG =  x + a  㡰⏌  Vx x r r dV = ò ò EG × d x Þv=



¥



x

Ax

Þ Vx - V¥ = - ò

x + a  㡰⏌  

¥

dx

A A -=  x  + a  㡰҈⏌  x + a  㡰҈⏌  㡰 㝐矄矄ᨨ 矄鼀鼀 ᨨ  ᨨ  �盐矄x  �ᆠ├ 矄矄 dx. æ x ö dm = r ´ px  dx = r çç ҈ -  ÷÷ ´ px  dx è R ø 㝐矄矄 ᨨ    \ Vx =

R



   g¢㦨

GM

黨黨 R㡰  R  �盐矄 ᨨ    矄 � ├矄 泐҈奠 

gἘ æ R ö =ç ÷  Þ gἘ>g g è 黨黨 R ø ҈ ҈×҈  ⏌矄㡰 矄� � g¢㦨 gRwᆠᨨ矄 f \

꾀 ⼄盐ᨨ

f㦨 

\

g¢㦨 gRw

 g¢㦨 \ w㦨

a

 A   ᨨ�  犨 ���ᨨ  �  ᨨ ᨨ   矄 ᆠ ᆠ ᆠ  ᨨ  � ᨨ GM G ҈ M 㡰 =  x ҈a - x 㡰 ҈  Þ = Þ  x = ҈a - x Þ x = a  �㡰 x ҈a - x㡰 矄� � ᆠᨨ 矄�ᨨ  ᨨ   �泐 犨 

GMm

GM

A

a x

㡰 ᆠ㡰 ᨨ鼀mg㦨

҈M

M

�㝐 ᆠᆠ�ᨨ  盐ᨨ��泐ᨨ� 㝐犨 �ᆠ Rp �矄 鼀� ᨨ� ᨨ  犨� �矄  ᨨ   ҈ é R p ⏌҈ ù - g pM = g p ê҈ ú = ҈[҈ - ҈] = 黨 鼀矄 R p úû êë \ ᨨᆠ㦨鼀矄矄ᨨ 犨�맔gpM㦨҈맔黨㦨҈ ҈҈



҈

�.e.g µ  d d  黨 ᆠ㡰 ␔├ ᨨ犨�Ἐ㦨�w ᆠᨨ矄q � = � - w   ෌�  � Ἐ = �  �  w =  � ҈ w= =   ´  ´ ҈ ҈ =  ´ ҈ -  ⏌矄  =  ´  ´ ҈ R  ´҈ =  ´҈� m ҈ b㡰 ෌�  R p = e = ҈ ҈

鼀矄矄 ᨨ  犨� Rp 㦨҈맔҈맔҈�㦨҈├� 꾀ᆠᆠ�ᨨ  盐ᨨ��泐  ҈ M 矄盐 ᆠᨨ         g p = prGRP 錐    ge㦨 prGRE  g p Rp ҈ ҈ = ҈ 鼀矄  \ Þ g p = = = ҈ ge RE ҈ ᔼ d>R�㦨

Topic-4 : Gravitational Field, Potential and Potential Energy

�.e.g µ d 矄�� � 㡰

d

g 㦨҈맔҈ ⏌矄 R

r

æ x ö M = pr çç x  -  ÷÷ dx R ø è

ò



r dx

x



r r -   �R ෌��ᨨ  �  Þ M = pr

E=

GM

r



=

æ r r� ´  pr ç ç  - �R  r è G

ö ÷÷ ø

WWW.JEEBOOKS.IN

PS-85

Gravitation



æ r r ö Þ E = pGr ç -  ÷ ç  �R ÷ è ø dE E�矄鼀 �鼀盐鼀犨   = dr æ ҈ r  ö dE Þ = pGr ç -  ÷ =  Þ r = � R ç  �R ÷ dr  è ø b㡰 ෌��ᨨ  �     矄盐 ᆠ Gm E=  r Gm Gm \ E҈ =  ҈  E =   r҈ r ᨨ鼀  ��鼀 ��  �  ⼄盐矄�ᨨ  E҈  = E   r҈㦨҈鼀R㦨m�� 㡰 

\

�



Ef㦨 

黨

矄 

=

Y

GM  a 

D

A

r



Mv  㦨 矄盐  ᨨᆠ r ᨨ犨 矄 ᆠ  \





҈ö Mv GM æ = + ÷  ç è ø æ a ö a çè ÷ø 

O

-෌㝐 æ ҈҈  ç   çè 



ú úû

和ᨨ� 矄 

ö ෌㝐 ÷ = -҈҈ ÷  ø

 ᔴ�泐

෌㝐   ෌㝐 =ᆠ�泐 =    和ᨨ ᨨ �    ᆠ  ᨨ ᆠ�泐 = 矄  - ᆠ�泐

B

҈ ö æ çè҈ + ÷  ø

Þ v=

GM a

GM ҈ ö æ çè҈ + ÷ = ҈҈ a  ø

C

r dV 㡰m GMm = òa 㡰 F = r r R

)

  泐 é ù  = - ê ò ᔼ + ò ᔼ 泐 泐 ú 㦨 é ᔼ  + ᔼ 泐 ù 泐 û ë êë  úû  㦨 éë � ( 䰘 -  ) + ҈ ( - -  ) ùû ᔼ=-

a

GM a

҈҈෌㝐 æ  ෌㝐 ö -෌㝐 -ç÷=  è  ø GM R   r  㡰 ҈ ᆠ㡰 꾀矄 V =   R ෌  ᆠ㡰鼀ᨨ矄ᆠᨨ矄泐 �ᆠ矄   ᆠᨨᆠ ��ᨨ  ᨨ v r㡰 ҈҈ 㡰 ෌��ᨨ  �  ᔼ = ��ˆ + ҈ˆ ⏌├� =-

(

a

�

Þ v =

R

-෌㝐 é  æ ö = ê - ç ÷ èø   êë

盐 ᨨ ᆠ�泐 ᨨ �  ᨨ�  P

AC a  a = =    矄盐  ᨨᆠ ᨨ    ᨨ 泐 GM  ˆ GM  ˆ GM  ᆠᨨ矄 �°�ˆ + 矄� �° ˆ 㡰 B㦨  � +   + a a a 㡰

a

GMm æ  ҈ ö GMm ç  + ÷ 㦨  R è  ø R 㡰 盐 ᨨ ᆠᨨ鼀 矄ᨨ�  矄  ᨨ �  ᨨ�  P Ef E�㦨



㡰 +

GMm ⏌  GMm ⏌  GMm GMm   㦨  æRö æ R ö R R ç ÷ ç ÷ èø è  ø

GMm GMm =R R \ �  ᆠ 犨  � ��   �   �泐

Q r=

GM 

GMm R

㦨 

æm ö ҈ Þ ç ҈ ÷ =  è m ø GM GM G  M 㡰 ᆠ㡰  E g = = +   a 㡰 a 㡰 a  b㡰 AC = a 

ᆠ㡰 ᔼ �����ᨨ  ᨨ �  �泐 E�㦨  �  ���ᨨ  ᨨ �  �泐

E҈ æ r ö æ m҈ ö  æ  ö æ m҈ ö =ç ÷ ç ÷ Þ =ç ÷ ç ÷  è ҈ ø è m ø E è r҈ ø è m ø

Þ F =

䰘



k  pr  dr æ ҈ö pkGm = - pkGm ç ÷ = = mG ò   è ø r R r  r 矄� � 犨ᨨ 矄 矄ᆠᨨ  犨 犨  mv pkGm = R R ᨨv㦨ᔴ ᆠᨨ 矄㡰 T pR pR

�鼀�ᨨ  T = = ᨨ㦨 㦨ᆠᨨ 矄  R v C

X

҈

㦨 - éë � + ( - ) ùû = ҈  ⏌ ├� � ᆠ  ��  ���ᨨ  ᨨ � ҈ ⏌├�  ᆠ ᆠ  � �  ���ᨨ  ᨨ �  �泐҈  b㡰 ␔ ᆠ ᨨᨨ矄   ᆠ ᨨ�  � � �泐 犨  ᨨ  �泐ᨨ    矄泐矄鼀 �矄 ᨨ 和ᨨ � ��  �泐ᨨ  矄泐矄鼀 㦨

҈ ҈ ෌鼀 ҈鼀  鼀 ҈ ҈ + 鼀      ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ   �泐 ᔼ ��  �泐㦨 �   �泐 ҈ ҈ ෌鼀 ҈ 鼀  \  = 鼀 ҈ ҈ + 鼀      

�  �泐㦨

ᨨ

෌鼀 ҈ 鼀  ҈ ҈ 鼀 ҈ ҈ + 鼀 ҈   =  ҈㡰  

WWW.JEEBOOKS.IN

EBD_8341 PS-86

Physics

泐 ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀  鼀 鼀 鼀҈҈ + 鼀   =  ᨨ ҈ = -  Þ  =  ҈ ҈  鼀҈ 鼀 盐� � 盐 ᨨ �  ⼄盐�ᨨ  ҈㡰 犨�

GMm ù é êëQ ෌��ᨨ  ᨨ �  �泐 =  r úû

Þ



æ 鼀  ö ෌鼀҈鼀  + 鼀  çç - ҈ ҈ ÷÷ = è 鼀 ø    鼀҈鼀  ҈ + 鼀҈ ҈ ෌鼀҈鼀  = 鼀

鼀҈҈

҈ =

෌鼀  鼀҈ + 鼀  㡰

= 鼀

҈䰘

෌ 鼀҈ + 鼀  㡰

㝐矄矄 ᨨ      ᨨ  ᨨ    矄  㝐 䰘 㝐Ἐ = 㝐= 㝐  

 ᨨ���ᨨ  �  盐ᨨ  ᨨᨨ   矄 

F҈ =

GM r҈

  F㦨

҈�

F ᨨ  ҈ =  F r

GM

r r҈ GM R

´r

F҈㦨



´ r҈   F㦨

GM

Y

=

҈ r

A 㜠㡰

æ æ ö ö çQ M = ç pR ÷ r ÷ è ø ø è

æ ö mv  é GM ù = mê   M㦨 ç pR ÷ r ú  r è ø ëR û

X

Z

���ᨨ  �  盐ᨨ鼀矄矄矄꾀 �졠�矄 ⼄盐 ᨨᨨ矄�꾀矄  ᨨ  矄ᆠ�ᆠ矄�矄Ӹ㜠^ ᨨ㜠 �矄矄ᨨᨨ � 泐ᨨ� ᨨ  矄犨ᨨᆠ�ᆠ矄犨� ⼄盐 盐ᨨ鼀矄矄M 鼀矄矄矄M  m

Þ v µ r

� v  r� �矄矄�� � 矄矄� � ᨨ盐� ᨨ���  㡰 ᔴ  � �  ᨨ �  �泐 B \ DU㦨UfU�

Topic-5 : Motion of Satellites, Escape Speed and Orbital Velocity

R

é ҈ ҈ ù GMm A 㦨GMm ê 㦨 ë R R úû R GM R ÞGM㦨gR Q g㦨  R O gR  m mgR = \ DU㦨 R  ҈ ҈㡰 矄� � 犨 ᨨ  ᆠᨨ 矄�ᨨ  ᨨ   �泐

ᨨ  �泐 ��  ҈  㦨 ᨨ  �泐  GM E m ҈ GM E m ҈  + mV = + mV  ҈ R   R

B 㡰

O



ᨨ \

GM

r

´ r R R F҈ r҈ = \ F r ҈ ᆠ 㡰 ���ᨨ  �  쟼㡰 �  矄�泐  ᨨ�  O � ᆠ ᨨ   矄ᨨ�  矄 �矄 ᨨ ᨨᆠᆠ� �ᨨ   矄 鼀矄矄mᆠ O F㦨mE㦨m맔㦨 ᨨ犨 y졔 z 㦨  矄 矄   ⼄盐�ᨨ  ᨨ  ᆠ�ᆠ犨� ᆠ  㡰  �盐矄 盐 �矄  ᨨ  ᆠ�ᆠ�矄  �ᆠ盐 ᨨ x㜠 �矄 \

mv  é GM ù  犨  M �矄   ᨨ 鼀矄矄 ᨨ   = m´ê ú r ë r û 矄 �ᆠ 矄泐矄鼀 \ v µ

GM

ᨨrR ���ᨨ  �  F㦨

䰘 ෌㝐    ҈ ᆠ㡰 ᨨ r ³ R =

᲼Q 㦨҈├鼀⏌矄�� 桌

b㡰 ᨨr>R ���ᨨ  � F㦨

\

෌ 鼀҈ + 鼀  㡰 ᆠ㡰 鼀矄矄ᨨ 矄鼀矄  犨 �ᆠ  矄ᨨ鼀ᨨ 㡰�矄鼀  �盐矄 = ᨨ鼀 ��盐㡰  㝐 㝐 鼀 Þ鼀= =    æ ö  p p ç ÷   èø

෌㝐 Ἐ

҈ ö V V  黨 æ ҈ = Þ V  = V + gR çè ÷+ ҈ ø   �

黨 Þ V = V + gR » ҈ km ⏌ s �

和�鼀�泐   = - 鼀҈

҈

GM E R

҈

㡰 泐 �盐 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ

mr鼀� v鼀 = mr鼀 v鼀�

v鼀�

r鼀�

r鼀  

v鼀 ෌�  v鼀� =

v鼀 

\

r鼀� v鼀� ҈ = = r鼀 v鼀 

WWW.JEEBOOKS.IN

PS-87

Gravitation 

㡰 졠�矄 ᨨ  ᨨ 泐犨  �ᨨ矄泐ᆠᨨ矄 ᨨ   矄盐 ᆠ ᨨ   

GM  �㡰 R  G 㦨 ���ᨨ  ᆠᨨ 矄  쟼矄ᆠ 矄  ᨨ鼀   矄盐 ᆠ ᨨ  

�

V =

GM R �� � � �㡰泐 ��㡰犨  Ve =



GM ҈ R = GM  R

V = Ve 

 ��㡰

ᆠ㡰

hv =

Q p K  G ᆠᨨ 矄 矄 \ T  µ R r r 㡰 ᨨ鼀犨ᨨ ᆠᨨ 矄�ᨨ ᨨ 鼀ᨨ鼀 盐鼀 p� = p f m҈u҈졔mu㦨MVf mv ö æ çè mv + ÷  ø �v Þ vf = = m   ᔴ泐vfv�\ 犨���ᆠ b㡰 ⧤쟼ᨨ 矄��矄 ᨨ 矄盐 ᆠ  ��  ᨨ鼀  �泐ᆠᨨ 矄�ᨨ

矄盐 ᆠ졔쟼҈㦨 

 V 

෌㝐 鼀 ෌㝐 鼀 + 쟼҈ =   (  + )

æ ҈ ෌㝐鼀 ҈ ö ´  Þ 쟼҈ = ෌㝐  鼀 ç ÷ Þ 쟼҈ = (  + )  è   + ø ෌��ᨨ  ᆠ�ᨨ

Re

෌㦨鼀ᆠ㦨

鼀  =

R鼀

쟼 =

V鼀� 

GM Re

졠� ᨨᆠ�泐 V =

ᨨ鼀  �泐ᆠᨨ 矄�ᨨ  

GMm ҈ æ  ö GMm ҈  + mç V÷ = + mV鼀�

Re R鼀   è  ø ᨨ鼀  �盐 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ



䰘

 ҈㡰

 VRe = V鼀� R鼀  㡰  和ᨨ� �⼄盐�ᨨ  ҈㡰  㡰犨� R鼀 㦨Re 㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  鼀矄矄  矄�泐ᨨ   矄 �ᆠ k � 泐�矄矄  r 㝐矄矄 M = ò rdV

ÞM =

r = R

ò 

R

 k pr  dr  Þ M = pk ò r dr r 

pkR = pkR   GMm = mw R = FC 㡰 FG = R



ᨨ M =

M R

pkR G  = w R Þ w = pKG  æQ w = p ö Þ ç ÷    T ø è R R p p R pR pR \T = = = Þ T = w KG KG pKG 

m

෌㝐 鼀 鼀  = (  + ) (  + )

෌㝐  鼀

(  + )

෌㝐 鼀 鼀 =  (  + ) 쟼҈㦨쟼 ᔴ泐 = ҈ Þ =  = ├鼀   

GM A RA 犨 MA RA 鼀矄矄  �盐矄ᨨ   A 꾀ᆠᆠᨨ � � ᨨ��  ᨨ鼀 M R M B = A  RB = A   GM A M G A RA n  \ VA = = =҈ \ VB = GM    VB  RA A RA   Þ n㦨 M M R u b㡰 R Þ R v m ҈  GMm ҈   GMm mu  + = mv +  R  R ҈  GMm Þ m v   u  㡰 =  R 㡰 쟼矄ᆠᨨᆠ�泐ᨨ   A�矄 VA =

Þ  =  = 盐  v =

GM R

෌㝐

\ vrad =

 �㡰 m´v = ҈ v æ mö çè ÷ø ҈

WWW.JEEBOOKS.IN

EBD_8341 PS-88

Physics

쟼ᆠ� �ᨨᆠ├ ᨨ 鼀矄矄

⧤� �ᆠ �泐ᨨ 矄� 

m ҈

GM m GM 黨m ´ = ´ vt Þ Vt = ҈ ҈  R ҈ R ⧤� �ᆠ  �泐 ᨨ  ᨨᆠ├ ҈M  VT + Vr ⧤쟼 rᨨcket =  ҈ ҈ m æ GM GM ö 㡰҈ + ҈ = ´ ´ ç u   ÷  ҈ è R R ø vT m æ  GM ҈ GM ö M M ´ ҈ ç u  + 㦨 ÷ è   R ø R ҈ R ҈҈黨 GM ö æ 黨M = �m ç u   ÷ ҈ è  R ø 㡰 �鼀 �ᨨ  ᨨ  ᨨ盐�ᨨ  ᨨ  矄� pr T= v GM r r v= \ T = p r = p r GM GM 和盐矄�盐� �   盐矄 犨 �

҈ 

㦨 鼀  

\

(

黨

)

㡰 ´ ҈҈

T = p

䰘 ´ ҈ -҈҈ ´  ´ ҈

㦨䰘҈矄

;҈䰘  Þ ҈҈ᨨ盐�ᨨ 矄 ҈ 㡰 쟼矄ᆠ ᨨᆠ�泐 vc =

GrV = R

GM = R

矄ᆠ

GS ´ pR = R

 prGR  

  prGRm  R     ෌�  pR =  ´ pRm ᨨ Rm =    Ἐ ᨨ 鼀ᨨᨨ  vc =

Ἐ \ ve =

҈҈

 v  æ Rö prG ç ÷ = c è ø   

҈  mve E v v E =  = Ἐe = e = ҈ ᨨE 㦨 v ҈ EἘ ҈ æ ö  e mv Ἐe vc çè  ÷ø  r b㡰 鼀�ˆ + 鼀ˆ = 鼀  r  Þ  = ˆ� + ˆ    

҈ ෌㝐 = ´  b㡰 졠�ᨨᆠ�泐㦨 ҈ 

� + 㡰 » �

쟼矄ᆠ ᨨᆠ�泐 㡰 �矄

 =

� + 㡰 » �

෌㝐 

᲼Q   桌

D =  -  =  - ҈㡰 �

vR

҈ b㡰 꾀 ��  ᨨ鼀ᆠ  ᨨ    ᨨ� ᨨᆠ�泐

෌㝐 r 泐 � ᆠ� ᨨ   �泐 ᆠᨨ 矄�ᨨ

æ ෌㝐鼀 ö ⧤쟼ᨨ �鼀졔 çè  ÷ =+  ø Q 꾀� � �泐쟼㦨⧤쟼㦨㡰 v=



෌㝐鼀 æ ෌㝐 ö 㦨ç 鼀㦨鼀 ᨨ ⧤쟼ᨨ �鼀㦨   ÷ø è ҈� 㡰 㝐�矄鼀矄矄ᨨ 矄鼀�矄鼀矄矄ᨨ 鼀ᨨ� 泐 �泐ᆠᨨ �ᨨ  犨     ¥. ෌㝐鼀 ෌㝐鼀 ҈  + + 鼀 矄 =  +     ෌㝐  ´ 䰘 ´ ҈ ҈҈ ´  ´ ҈҈ = \ 㦨  ҈҈҈ ;  ´҈� 鼀 ⏌ 矄 ҈ b㡰 꾀泐� �  �泐ᆠᨨ 矄�ᨨ

GM e m GM e m ´  ´҈� ҈ mVs  = Re  � ´҈ Re

Vs  GM e é  ´҈� ù = ê҈ + ú  Re ë � ´҈ û ö Gme æ GM e ö æ Vs = ҈ ç = ҈҈ ├鼀 ⏌ 矄 ÷ ççQ Ve = ÷ ÷ Re è Re ø è ø \ Vs㦨 ҈ ´ ҈҈ »  鼀 矄 ҈䰘 b㡰 ᨨ   ᨨ�ᨨᆠ�泐�矄 � 쟼矄ᆠ ᨨᆠ�泐㦨 � \ 鼀� �鼀盐鼀� ᆠ矄� �矄ᨨ�ᨨᆠ�泐 ҈

㦨 �  � 㦨 �   ҈㡰 ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ 盐 �矄 犨 ᨨ ෌��ᨨ  ෌��ᨨ  ᨨᆠ 㦨

⧤� �ᆠ  �泐ᨨ 矄�꾀 

꾀㦨 鼀 꾀 꾀

㡰 ᨨ  矄� ᨨ�� � ᆠᨨ矄 ᨨ     ᨨ� ᨨᆠ�泐�矄 ��  泐

 =



 r æ ö æ ö Þ = ç ÷ +ç ÷ = è ø è ø 

҈

҈

෌㝐 鼀´

꾀 Þ 㦨 ෌㝐 㦨҈  鼀 ´ 

꾀矄ᨨ 盐



෌㝐鼀 졔 㡰

mv  GM GM m = ҈黨 㡰 F = m  ᨨ r Lr Lr  GMm é p ù æ p ö mr ç ÷ = Qv = r w  w = T úû Lr êë èT ø Þ T µr

쟼

WWW.JEEBOOKS.IN

PS-89

Gravitation 

㡰 꾀矄犨├ ᨨ犨



-GMm ෌��ᨨ  ᨨ �  �泐㦨 r  ᨨ�ᨨᆠ�泐v㦨 ෌㝐 ⏌ + ҈ ෌㝐鼀 ҈ ෌㝐 ෌㝐鼀 쟼 = 鼀 = 鼀      ෌㝐鼀 æ ҈ ö - ෌㝐鼀  = ç - ҈÷ =  è  ø  -෌㝐鼀 +⧤  쟼� = E�㦨Ef

҈ 맔⧤쟼ᨨ 矄ᆠ  ҈ GMm ҈ ᨨ mv 㦨 ´  R  GMm GMm GMm =\ R R R+h ҈ ҈ Þ R 졔 h = 2R ᨨh = R =Þ R+h R æ ෌ ö � ç

ᨨ鼀ᆠ  �ᆠ �泐鼀矄矄 ma ç 㝐҈ 졔 㝐  㡰 ÷÷ è ø 鼀� 犨泐ᨨ�  犨    ᆠ 矄 ᨨ     鼀ᨨᨨ

⧤쟼ᨨ�  㦨

�෌㝐鼀  b㡰  �ᨨ  犨  矄ᆠ 矄  V e  

 ᨨ鼀� �鼀盐鼀⼄盐�  �泐 ⧤ =

҈

ᨨ�ᨨᆠ�泐Ve㦨 V  ├� �ᆠ �泐 �鼀ᨨ ᆠ�ᨨ

ì é GM ҈M  GM ҈m GM  m ù é GM ҈M  ù ü - 㦨 í ê úý d d ⏌ d ⏌  úû êë d ûþ îë

҈ ҈ mVe = m  V 㡰 = mV     㡰  h    �� ᨨ 犨 �ᆠ   盐 �矄矄 犨�    ��  ᆠᆠ�ᨨ  盐ᨨ��泐�矄 矄

KE =

æ è

g҈㦨g ç҈ +

hö ÷ Rø



Þ

g hö æ 㦨� ç҈ + ÷  è Rø

Gm M҈ + M  㡰 㦨� � � �泐㡰 d ⏌ ⧤� �ᆠ �泐⼄盐�  ᨨ矄ᆠ 鼀矄矄 �mᨨ � � �泐 ҈ Gm \ M҈ + M  㡰 mV e =  d  犨 Ve�矄 ᨨᆠ�泐犨� 犨 �ᆠ 鼀矄矄m�矄 ᨨᆠ  G M҈ + M  㡰 Þ Ve㦨 d 㦨



Þ

h㦨R

GM 㦨 v N  �� 㡰 �㡰 R ᨨ犨 泐� � ᆠᨨ 矄�ᨨ  ᨨ   �泐 � ᆠ� ᨨ矄矄ᨨ ├� �ᆠ �泐㦨�� � ���ᨨ ᨨ � �泐 GMm æ GMm ö ҈  ç mv 㦨 \ R R ÷ø  è

␔├ ᨨ犨矄ᆠ矄 ve㦨

GM R ᔴᨨ鼀� �⼄ �㡰 ��㡰犨� N㦨 \



\

vp ve

gp

=

g

´

Rp R

gp

 �㡰

ve

=

\ vp =

   ´   ´ = = ҈҈  ҈҈ ´  ҈҈

  ´ ve = ´҈҈├鼀⏌矄 =  ├鼀⏌矄 ҈҈ ҈҈

h㡰꾀ᆠᆠᨨ � �ᨨ⧤Ἐ矄犨 T  µ R \

T҈

R҈  = T R

 R҈ = R +  R = 䰘 R  R㦨�R졔R㦨�R T҈㦨  ᨨ盐矄 \

 gR

 ෌�  㦨  ��㡰 ge ҈҈ g p r p Rp  꾀矄ᨨ g = p G rR  \ = ´  r ge R r é ù  R    p = �� 㡰ú êQ \ = ´ ҈҈  R ë r  û Rp   \ =  ���㡰 R   ᨨ鼀 �㡰 ��㡰 ���㡰 vp



 ��㡰

v㦨

㡰 ␔ ├ ᨨ犨   矄ᆠ 矄  v =

㡰 ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ 鼀ᆠ  �ᆠ  �泐 GMm ҈ æ GMm ö mv  + ç ÷= - R+h R  ( ) è ø

䰘 

 ´ 

T

=

䰘 ´ 䰘 ´ 䰘 ´ R � ´ � ´ � ´ R 

 Þ T㦨

矄 犨  � �矄 ᨨ ᨨ    ⼄盐ᨨ�   ෌ᨨ矄�ᨨ 泐矄��矄盐 ᆠ  ᨨ  ⼄盐ᨨ�  b 㡰   矄 P   Q    矄鼀 盐 � ᨨ鼀  矄�泐�r  矄盐 ᆠ 矄 A   A 矄ᆠ�泐   鼀矄矄ᨨ P, MPm

  éAù

  m = r´ pr  = r´ p ê ú   ë p û

 é Aù

鼀矄矄ᨨ MQ㦨 r´ p ê ú  ë p û

⏌

⏌

=鼀

\ 鼀矄矄ᨨ  R㦨鼀졔鼀㦨黨鼀 ᔼ   �盐矄ᨨ P㦨r

   �盐矄ᨨ Q㦨r ⏌  ⏌  ù é æ Aö æ Aö = ç êQ rQ = ç ú ÷ ÷ è p ø è p ø êë úû ҈⏌   �盐矄ᨨ R㦨黨 r

éQ M R = M P + M Q ù ê ú     êë rR = r + r 㡰 = 黨 r úû

WWW.JEEBOOKS.IN

EBD_8341 PS-90

Physics

꾀矄 犨 ├ ᨨ犨 矄ᆠ ᨨᆠ�泐 ᨨ鼀     Ve㦨

vQ㦨

vR 㦨 黨



MB㦨҈M

GM P GM =  \ vP㦨 Rp R GM Q

G 黨 鼀㡰 ҈⏌



r

⏌ 

T҈ æ R҈ ö ҈ =ç ÷ 㦨 T è R ø  㡰 꾀  矄ᨨ   �    ᨨ�� � 矄ᆠ 矄�ᨨ  ᨨ     � ᆠ矄犨�� 矄矄矄 �矄� 矄ᨨ   

 ᨨᆠ ᆠ� � ᨨ  矄ᨨ   �矄 盐��矄  �  ᨨ� � �

ᆠ矄矄泐 ᆠ � ᨨᆠ 꾀泐� � 鼀ᆠ  �ᆠ  �泐 ᆠᨨ 矄�ᨨ 

ᨨ �泐A㦨 ᨨ  �泐 B ⧤쟼㡰A 졔 쟼㡰A 㦨 쟼㡰B  µ  \

 ҈ GM é -GMm ïì  æ 黨黨 R ö ïü ù GMm m´ +ê R - ç í ýú = ÷  è ø  ҈ ï ú R R+h êë  R ïî þû

B

㝐 �鼀盐鼀 �� �  泐   ᨨ 泐 ᨨ鼀   矄盐 ᆠᨨ    㡰



ve A R

R ҈ 黨黨R ҈

   ᨨᆠᨨ  ᆠ�ᨨ  �矄 ᨨ   �矄 ᆠx ᨨ鼀   ��� 矄

GM S m

㦨 -

=



 Þ

҈ M

M

=

Þ x㦨a x ҈a - x㡰  x ҈ a - x㡰  v  ᨨ ᨨᆠ�泐犨�  犨 �ᆠ    ᨨ 泐ᨨ 鼀矄矄 m �矄 �  矄ᨨ   � ᆠᨨ矄矄矄 P ᨨ � OP   �泐 �矄 ᆠᨨ 矄 

  �泐ᨨ   矄泐矄鼀 ᨨ  矄 鼀矄矄矄㡰 � ��泐 㦨 �  �泐犨  m�矄P GM B M S GM B m GM S m ҈  + mv ҈a a a  

和ᨨ� � ᨨ ⼄盐�ᨨ  犨 �h㦨黨黨�R

和鼀 矄

x

GM B m

= 黨҈⏌ v P

 ᆠ㡰 ᨨᆠ ᨨ  矄� �矄 犨泐矄 ᨨ犨 矄   犨 �ᆠ ᆠ矄 矄�犨�  ���ᨨ  ᨨᆠF  ᨨ ᆠᆠ�ᨨ ᨨ 矄�S�矄犨泐矄 �ᆠ ᨨ犨 矄ᆠ  ᨨ    

 ᨨ⼄盐ᨨ  �矄���ᨨ  ᨨᆠFᨨ盐ᆠ ᨨ   �矄 ᨨ  ᨨ  �盐 鼀ᨨ鼀 盐鼀 ᨨ  �

鼀� �盐    �ᆠ�ᨨ 㡰 ᨨ  S ᨨ盐 ᆠ  ᨨ    �矄 ᆠᨨ 矄   ᨨ盐� ᨨ盐 꾀矄   ᨨᆠ F �矄 ᆠᨨ 矄� �  盐   ᨨ 鼀ᆠ  �ᆠ  �泐ᨨ 矄�鼀� 矄 ᆠᨨ 矄  和  ᨨ S �矄 鼀 �鼀盐鼀 犨   � �矄 矄 ᨨ     鼀� �鼀盐鼀 犨  � �矄  矄 b㡰 Q 졠� ᨨᆠ�泐

Þ

a O'

҈a

V҈ R  GM ҈  ᨨVµ = \ 㦨 R ҈ V R҈ R L҈ m҈v҈ R҈  ´  ´҈ ҈ 㦨 㦨 㦨 L m҈v R ҈´҈´  ҈ GMm ⧤� �ᆠ �泐K㦨  R k҈ m҈ R҈ ´   ´ \ 㦨 㦨 㦨 ҈´ ҈ ҈ k m R ᨨ鼀⧤Ἐ矄犨ᨨ  泐鼀ᨨ�ᨨ 



P

  ᨨᆠᨨ 鼀矄矄m 盐ᨨ���矄㦨 ᨨᆠᨨ 鼀矄矄m  盐ᨨ矄鼀矄

V㦨

҈

O a ��� 矄

G 鼀㡰 = v P r

=

RQ

Gm r

MS=M



GM B M S GM B m GM S m ҈a a a

᲼Q M B = ҈M 錐 M S = M 桌  �GM  a  �㡰  ᆠ � ᨨᆠ �矄 ᨨ�   泐  ���ᨨ  盐 v mv  GMm A m = \ R + h㡰 R + h㡰 \ v㦨

h

B

Þ

GM v㦨 R+h

R

M

E

҈ ҈ GM ve =   R ҈ æ GM ö GM Þ R졔h㦨R\ h㦨R㦨├鼀 \ ç ÷= è R ø R+h ��㡰      矄  犨�  犨 �ᆠ    矄� �矄   矄盐 ᆠ ᨨ      ᔼ    矄� �矄 矄ᨨ  �矄 ├� �ᆠ �泐�矄 ᨨ␔  � 矄 泐ᨨ  쟼  �矄 ᨨ �  �泐 ᆠ矄矄   ᆠᨨ 矄 � ᨨ ├� �ᆠ  �泐 \ 쟼㡰A 쟼㡰B㦨⧤쟼 -GMm æ -GMm ö ҈  -ç = mv Þ è R ÷ø  R ෌� v㦨

GM = gR = 黨 ´  ´ ҈ R 㦨䰘黨鼀⏌矄㦨䰘黨├鼀⏌矄 �  � ��ᨨᆠ�泐 矄 ᨨ盐 �� ᨨᆠ �ᆠ  �  ᆠ � ᨨᆠ �矄 ᨨ�    泐  矄盐  ���ᨨ  ᆠ�ᨨ  ᨨ   犨ᨨ 鼀矄矄矄 Þ v㦨

m

FR㦨 F  + F  +  F  ᆠᨨ矄 ° 㦨  F =  G \

mv  G  = r a

m´m a



O

m

a⏌ Ö

F

FR

m

F

a

m

v

WWW.JEEBOOKS.IN

PS-91

Gravitation

æ mv  ö = ᆠ � ᨨᆠ÷ ç è r ø

㝐矄矄ᨨ  � �dM㦨spxdx㦨

 �盐矄ᨨ  ᆠ�ᆠ盐 r㦨

Gmr

a   a a 㦨   

R

K dr Þ Gm

K  pr  mG

r r 㡰 K r K = = ᨨ    m m  pr m G pr mG 㡰 㝐矄矄 盐 �  ᨨ  矄     M M 鼀矄矄 = = s㦨  p  R㡰  - R㡰  㡰 䰘 pR   盐矄 ᆠᨨ 矄�   � � ᨨ  �盐矄 x    �ᆠ├ 矄矄 dx 矄 矄 ᨨ犨  �    ��盐 \



r=

䰘pR



R

ò

R

xdx ҈ R + x 

R GM  p é GM ҈ R  + x  ù =   - �㡰  ëê ú û 䰘R 䰘 pR R ␔ᨨ├ ᨨ � 鼀ᨨ� �盐 �鼀矄矄 ᨨ鼀ᨨ¥㦨V¥VP

æ - GM ö GM   - �㡰 ÷ =   - �㡰 䰘R è 䰘R ø 䰘㡰 ᨨᨨ� 鼀矄矄 �矄 ᆠr㦨l

ᨨ WP¥㦨 ç 

GMm l 㡰 㝐

+

Gm l

㦨ma



鼀 l

r㦨l ᨨᨨ� 鼀矄矄 �矄 ᆠr㦨l

GMm l 㡰 \

K dM = dr Gm

pr  dr r =

 R㡰 + x 㡰



GM p

VP㦨

mv GMm GMm GMm ҈ = Þ mv  = ÞK=  r   r r r Kr K \ M = Gm �  �� �   ᨨ m ⼄盐�ᨨ 犨ἘrἘ犨� dr r dM dM  K = dr Gm M

\



=-

和ᨨ� � 犨 �

b㡰 ෌��ᨨ 盐ᨨ  鼀矄矄ἘM Ἐ矄 �  矄  ᨨ  �盐矄Ἐr Ἐᨨ�  ⼄盐� ᆠ � ᨨᆠᨨ �ᆠ ᨨ 鼀矄矄�mᨨ盐� ᆠ�ᆠ盐 

ᨨ

GdM

-

R

a pr  p a ⏌  = = p 

㦨 Gm v Gm a

҈

ò

VP㦨

 G ma

Topic-6 : Miscellaneous (Mixed Concepts) Problems

䰘pR 

ᨨ �  ᨨ�  P 盐 ᨨ矄    

Gm v = =  Þ v =  a a ´  a

�鼀�ᨨ ᨨ ᆠ�ᆠ盐鼀ᨨ�ᨨ



pMxdx



-

Gm  l

GMm l㡰



+

㦨ma

Gmm l



=

GMm l㡰





Gmm l

䰘M é҈ ҈ ù Þ m㦨 \ K㦨䰘 ú  ë 黨 ҈ û b㡰 ᨨ鼀 ᆠᨨ 矄�ᨨ  ᨨ  鼀ᆠ  �ᆠ  �泐 -GMm GMm ҈  + mv 㦨졔  L L \

m㦨 M ê 

ᨨ

҈  GMm mv 㦨  L

GM GM = L L

V=

\ 



ᔴ 







P R dx R

R x

WWW.JEEBOOKS.IN

EBD_8341 PS-92

Physics

Mechanical Properties of Solids

8

Topic-1 : Hook's Law & Young's Modulus ҈

-A

ᆠ㡰 ෌�  U =

r



+

B

�

r҈

ᨨ⼄盐���盐鼀

p ´  ´ ҈- 㡰 ᆠ㡰 Dl҈㦨Dl ᨨ

dU = - A -r -䰘 㡰㡰 + B -҈ r -҈ 㡰 =  dr  A ҈ B A ҈ Þ  = 䰘 - ҈ Þ =  ҈ B r r r F=

æ B ö \ 和�ᨨ  犨  鼀ᨨᆠ盐矄 r = ç è A ÷ø



Fl҈



Fl pr y

҈⏌ 

和矄矄҈ =

- A A - A + = B B B FL F FL =  ᆠ㡰  La DT㡰㦨 \ a㦨 AYT pr YT AY ᔴᨨ �ᆠ�  ᨨ  ᨨ盐鼀  矄矄�ᨨ

F g㦨a㦨   pr YT ᨨ 盐矄㡰

和矄矄 æ Dl ö çè ÷ø L

 s    矄矄矄

ᨨ ᨨ ��ᨨ  Dl  =

é҈ ҈ù Dl  = s ê + ú ë Y҈ Y û

sL҈ sL + Y҈ Y

᲼QL҈㦨L㦨҈鼀桌

æ YY ö s = Dl ç ҈  ÷ è Y҈ + Y ø



N æ ҈ ´  ö =  ´ ҈- ´ ç ´ ҈黨 =  ´ ҈  è ҈ ÷ø m ᆠ㡰 ෌�   �盐矄ᨨ 犨�r㦨鼀鼀 㝐矄矄ᨨ  ᨨ 鼀㦨├� F mg 和矄矄 = = A p r 㡰 

R ´䰘

=

҈� 

 ´

҈� ᨨᆠ҈ = ҈ ҈ 㡰

和矄矄 =

҈� ᨨᆠ =    㡰

x ᆠ  ��  �  = ᨨ���  �   x �矄   �矄ᆠ鼀  ᨨ 矄ᆠᨨ  ᨨᆠ├ 和�  =

ᨨ矄鼀鼀�



ᨨ

䰘

҈㡰

矄矄矄҈ 矄矄矄 = 矄� ҈ 矄� 

҈�

҈�

Ӹᨨ盐 �Ἐ矄 鼀ᨨ 盐盐矄 Y =

 

ᆠ  ��  � ҈ � ´ ҈- = ᨨ���  � ҈ ҈ ᨨ 矄ᆠᨨ  ᨨᆠ├

A B +   ÷=B ⏌ A B ⏌ A ø

和

ᨨ

和� ҈ =

҈⏌  ö

矄矄

= ҈ ´ ҈ ⏌鼀

\R㦨҈䰘�鼀鼀 b㡰 ᨨ矄鼀鼀�  �ᨨᨨ 矄矄矄ᨨ矄� �矄矄鼀 ᨨ �矄 ᆠ盐

 =



=

pr҈ y҈

ᨨ �  �泐

æ æ B ö U çr = ç ÷ è Aø è

 ´ ҈p

=

=

㡰 x 

� ´ ҈ - ҈ 和ᨨ� �犨�x㦨�ᆠ鼀 ᆠ㡰 ᔴᨨ 矄� 矄鼀鼀  ᨨ  �盐矄

 졔   꾀 ⼄盐���盐鼀 ᆠ  ��   � ᨨ  犨�



㦨

҈

ò  = ò 



㝐� 

é  ù + ú 泐 pê  ë û



├� ��鼀� ᨨ鼀ᨨ

é ù 㝐� ê ú 㝐� ê ҈  ú 㝐� D = ´ =   ú  p泐 ê é  ù ê ú p 泐 + úû êë êë  úû 



WWW.JEEBOOKS.IN

PS-93

Mechanical Properties of Solids

⼄盐���盐鼀    � ᨨ 犨�㦨졔D

= + 

æ ҈ 㝐� ö =  ç҈ + ÷ p Ӹ è  pӸ  ø 㝐�

҈

㡰 ෌�   lc㦨  鼀錐 ls 㦨 ҈ 鼀錐 Yc 㦨 ҈ 맔 ҈҈҈ ⏌鼀  Ys㦨맔҈҈҈⏌鼀



DL = α DT L 꾀矄  �  �矄 ᆠᨨ 矄 㡰 㦨맔҈҈҈맔҈҈맔҈�맔҈㦨맔҈ æ 鼀㝐 ö b㡰  矄�ᨨ �  犨� = ç ÷� è鼀+㝐ø ᨨᆠ ⏌  矄�ᨨ

鼀㝐 � = 和矄矄㦨 꾀 꾀 鼀 + 㝐㡰  鼀 ´ 鼀㡰�  =  㝐㦨鼀�� 㡰 꾀 鼀 + 鼀㡰

҈鼀

鼀

Ts 

Tsᆠᨨ矄

和� 㦨

黨

҈

鼀  鼀� �=  = 鼀꾀 꾀 ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  l矄  泐 Dl矄 =  矄 =  矄 = ᆠ =䁸 l  泐 Dl  꾀矄 泐 =

Dl 矄 =

Dl  =

鼀�l 矄 p矄 泐矄

p 泐 

҈

Þ

Dlc æ Tc ö æ lc = ç ÷´ ç Dls è Ts ø è ls

Tc ҈ = Ts 

Þ

Yc ҈´ ҈҈҈ ҈ = = Ys  ´҈҈҈ 



Fl ADl As㦨Ac

Dl㦨

Fl AY

ö æ Ys ö æ ҈ ö æ  ö æ  ö ÷ ´ ç ÷ 㦨 ç ÷÷ ´ ç ÷ =  ÷ ´ çç ø è Yc ø è  ø è ҈ ø è ҈ ø

├� �矄矄矄s㦨맔҈䰘鼀 꾀 ᨨ  ᆠᨨ矄矄㜠矄ᆠ�ᨨ   㦨 ҈0 ᆠ鼀

s=

T ml w  = A A

(

)

 ´ ҈䰘 A ml w  £  ´ ҈䰘 Þ w  £ A ml

F A Dl l 

F A

lc  = ҈ ls

Ts = Tc 

㦨㝐lw

⏌ p  㡰 ⏌ p  Ӹ= = Dl҈ ⏌  Dl  ⏌  㡰 矄� �Y㦨

\

Þ

㝐 �鼀盐鼀 �盐矄 w㦨䁸

Dl 矄 p  泐  = 矄 矄 =  \ Dl  㝐�l   ᔴ p 泐 

҈

Ts Tc  =  

㝐矄矄ᨨ  ᨨ 泐鼀㦨҈├�

 ᲼Q  = 㝐�桌

ᆠ㡰 矄� �Y㦨

Þ

҈� 㡰 ෌� ␔� � l㦨鼀

㝐�l 矄

҈҈

Tcᆠᨨ矄

꾀⼄盐���盐鼀Tsᆠᨨ矄 㦨Tcᆠᨨ矄

\

 ᲼Q 矄 = 㝐 + 㝐㡰�桌

㝐�l 

Tc 

҈

ᨨ鼀Y㦨

l l Þ Dl = 꾀Dl 꾀泐





矄矄矄 㡰 Ӹᨨ盐 �Ἐ矄鼀ᨨ 盐盐矄Ӹ㦨 矄�

和矄矄㦨Ӹ´矄�

和矄矄 �  矄犨� 㦨꾀�  矄矄盐 矄矄盐㦨矄矄矄㦨Ӹ맔矄�

(  ´ ҈ )(҈ ) = ҈ Þw £ 䰘

Dl \  = Dl҈

 ´ ҈ Dl F l = =   - - l A Dl ҈ ´ ҈

=  ´ ҈҈҈  ⏌ 鼀   T⏌A T ´l T l 㡰 矄� �Y㦨  Þ Dl = = ´ Dl ⏌ l A´Y Y A æ T ö l \ Dl µ  çQ �矄 ᆠᨨ 矄  ÷ è Y ø A

l  �矄 �矄 �  㡰  ᆠ�矄   矄�ᨨ  꾀

Þw



-

鼀 㦨 ⏌矄 ҈ ´  ҈ b㡰 ᨨ鼀�  鼀 �鼀盐鼀矄矄矄 ᆠ 犨� 矄  ᨨ├� � �矄 �    Q

和�

㝐 矄� 㡰 㝐 矄� 턼㡰

㝐 �鼀盐鼀 矄矄矄ᨨ 턼

和矄矄

㝐 矄矄矄 ᨨ 

矄� ᨨ P�矄鼀ᨨ  Q  ᨨP�矄鼀ᨨ 盐ᆠ�

WWW.JEEBOOKS.IN

EBD_8341 PS-94

Physics

矄矄矄 和ᨨ�� 矄� 矄矄矄�矄鼀ᨨ ᨨQ 矄�

\ Ӹ턼>Ӹ

Q Ӹ =

矄� �⼄ �㡰 ��㡰 \

Topic-2 : Bulk & Rigidity Modulus and Work Done in Stretching a Wire ҈



㡰 ᔼ  ᨨᆠFᆠ矄ᨨ �  � ᨨ  犨�ᨨ ᆠᨨ矄矄㜠 矄ᆠ�ᨨ A     �泐矄ᨨ �  盐 � ᨨ盐鼀 ᨨ 犨� �矄 ��  泐

�





  ᨨ鼀 ᨨᆠ 㦨 㦨 꾀 p 㡰 꾀 和矄矄 㦨 맔矄�



和矄矄 㦨

㦨 

F X ö ҈ F F æ = ´ ´  çèQ 矄矄矄 =  矄� 㦨 ÷ø A AY  A AY ҈ F ҈ F  ´ ҈ ҈ F  ´ ҈ = =  AY  pd  㡰 Y  pd Y ᔼ u҈  u   矄��矄 ᨨ 犨ᨨ犨�矄  

dr mg =  ᆠ�ᨨ  ᆠ鼀 �  �盐矄㡰 r Ka

 p     㦨  p 㡰 p 

҈ 쟼 �泐  矄�泐㦨 矄矄矄 맔 矄�



=

dr mg = r Ka

d҈ d u҈ æ d  ö ҈ = ( ) Þ ҈ =  ҈ =ç ÷ Þ d d u è d҈ ø   㡰 ␔    ᆠ盐�矄 矄ᆠ   盐 ᨨ �  l      矄ᨨ  �泐� �㦨D├쟼Þ

p 㡰    

p   ᨨᆠ    ᨨ 盐矄    ᆠᨨ├ 㦨 m 㦨 mp   㦨 pm㡰D ᆠ㡰 和 � � 矄� �矄 ᆠ ᨨ �   矄�  矄盐 ᆠ ᨨ  盐 ᆠ   �矄├ᨨ   ᨨᆠ矄  ᨨ   �矄├     ᨨ �   ᆠ�ᆠ盐鼀  ᆠ ᨨ    �矄├     ᨨ ᨨᆠ    ᨨ  �矄 ᆠ  ᨨ 泐 



mv  L ҈ æ YA ö ҈  ç ÷ DI 㡰  = mv   Þ y =  è Lø  D Dl 㡰 



鼀㦨├� 㦨鼀矄҈ 㦨鼀 꾀㦨 p 㡰⏌ 㡰 㦨맔҈鼀 Dl 㦨鼀 y=

 盐矄 矄矄盐鼀     矄 � � 矄矄矄 ᨨ �   矄�  矄盐 ᆠᨨ   �矄├ �矄 盐 � ᨨ鼀  

=

 ´  ´  ´  

ᆠ㡰

Þ

ᨨ盐鼀ᨨ 矄  V =

æ҈ è

矄盐 ᆠ

ö ø

㦨 黨䰘 ´ ҈ ;  ´ ҈  

 �㡰

  pR 

҈ æ YA ö  x  çè L ÷ø ␔ᨨ├ ᨨ  W㦨 犨 K㦨

dV dr = V r



- -  㦨 � ´҈ ´ ç ´ ҈ ÷ ´  ´҈ ´ p



ᆠ�ᨨ  ᆠ  �� ᨨ盐鼀

矄盐 ᆠ

ò

æö ÷ èø

mg æ dV ö aç ÷ èV ø

dV mg = V Ka

s 鼀 꾀 = s 鼀

㦨 ò s 鼀 꾀 = s鼀 p ç

㦨맔҈⏌鼀

ᨨ盐鼀�ᆠ 矄矄矄 盐├ 鼀ᨨ 盐盐矄 ⧤ = ᨨ盐鼀�ᆠ 矄�

K=

ò

鼀 =

矄盐 ᆠ

p ´  ´ ҈ ´  和ᨨᨨ �矄҈



ò

 ��㡰

\

YA L

҈  Kx  

x㦨  矄�ᨨ � 犨�

҈ æ YA ö  ÷x è L ø

W㦨 ç

WWW.JEEBOOKS.IN

PS-95

Mechanical Properties of Fluids

Mechanical Properties of Fluids

9



Topic-1 : Pressure, Density, Pascal's Law and Archimedes' Principle ҈

= A ҈  㡰r°c g

㡰 ᔼ ⼄盐���盐鼀mg = Fe FB = V r g  鼀矄矄㦨 ᨨ盐鼀맔  矄�泐

ᆠ鼀

  p R  - r  㡰r g = pRr w g   r 䰘 ෌�  �  矄�泐  = rw 

 ᔴ



\



r 黨 ҈ r  r = Þ ҈- =  Þ =   R  R R  䰘 ҈⏌  r æ ö r Þ = ç ÷ Þ҈-  = è ø R  䰘 R

Þ ҈-

r

 ҈黨 Þ  = ҈= 䰘 䰘 R 

�

R

pr R    ´ = pR rl  �  

x҈ x + rSx 㡰 g ×   

U f = rSx f 㡰 g ×

xf





´

泐ᨨ盐鼀ᆠᨨ 矄�ᨨ 



xf xf

Sx҈ + Sx = S  x f 㡰 x +x xf = ҈  

x

 =

ù rSg é x҈ x - x҈ x ú  = rSg x҈ - x 㡰 ê +  êë   úû 

\ rl =

r �

㡰  P҈ P    P    矄矄盐  ᨨ� 矄 M N   O 矄ᆠ�泐 M P҈ 㦨 r F҈ N P㦨�rg F  㦨҈� g P  O 矄矄盐�矄�� 泐P㦨rgh ᨨ犨P҈㦨 Qh㦨㡰 P 㦨rg �㡰 P 㦨rg ҈�㡰     㦨҈�rg

P҈ + P 㡰 A  P + P 㡰 ᨨᆠ ᨨ  ᨨ犨  F =  A  F �rg � ҈ \ ҈ = = = F rg  

ᨨᆠᨨ  盐 F҈ =

␔    �矄 ᨨ   ᨨ矄矄 �  ᨨ � �泐 ᨨᆠᆠ盐 � 犨 ᆠᨨ鼀矄鼀

DU = U � - U f éæ x  x  ö ù DU = rSg êç ҈ +  ÷ - x f ú  ø êëè  úû    éx x æ x҈ + x ö ù ҈ Sg = r + ê ú ç ÷   è  ø úû êë 

ᆠ㡰 ᨨ 鼀� �鼀盐鼀  矄�泐 ᨨ  �⼄盐�  矄ᨨ�  矄  矄 ᨨ ᨨ ᆠᨨ鼀泐�鼀鼀矄 㡰 �    �⼄盐�  mg㦨FB 矄ᨨV�鼀鼀矄 㦨Vᨨ㡰

é r r� ù  Þ pr ê   ú = pRrl êë  �R úû  

㡰 ᔼ �� ᨨ �  �泐

� ᨨ � �泐

 ᔴ

  pR r l   é ù æ r ö êr r 㡰 = r ç ҈   ÷  < r £ R �� ú êë úû è R ø  R æ r ö  Þ ò r  p ç ҈   ÷  r  dr = pR r l  R ø  è

ᆠ㡰 ෌�   �盐矄ᨨ �盐㦨҈ᆠ鼀 犨 ᆠᆠ�ᨨ ᨨ 盐a㦨黨ᆠ鼀⏌矄

U҈ = rSx҈ 㡰 g ×

r°c  = = ҈҈ r°c 䰘黨

҈ᆠ鼀

ᨨ ò rdV =

 \ r = 黨 R = R 黨

盐ᨨ泐  r犨 㦨҈�ᆠ鼀 p  p ᨨ盐鼀 V = r = ´ ҈㡰 = ҈黨 ᆠ鼀 a   F盐ᨨ泐  F盐ᨨ泐  - mg = ma Þ m = mg g 졔a V rw g 㡰 V rw ҈黨㡰 ´ ҈ ҈黨 \m = = = = = ҈�� a 黨 g+a ҈҈ ҈+ ҈+ g 黨 

҈ᆠ鼀

␔  ᆠ泐� �矄 ᨨ� �� 犨 ᔴ  盐矄 = A h  h҈ 㡰r°c g = A ҈  ҈㡰r°c g 

é æ r ö  ù 䰘 Þ ê҈ - ç ÷ ú rw = rw è Rø ú  ëê û 

ᆠ㡰 ␔  ᆠ泐� �矄 ᨨ� �� 犨 ᔴ  盐矄 = A h  h҈ 㡰r°c g

䰘

b㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  ҈졔 㦨黨맔졔҈ Þ ҈졔 㦨 矄矄盐� 犨ᨨ鼀矄ᨨ 盐㜠盐�矄⼄盐 \ 졔r├� ҈㡰졔r犨� ҈҈㡰㦨졔r犨�  ᲼r├ 㦨  矄�泐ᨨ ├ᨨ矄 r犨 㦨  矄�泐ᨨ 犨桌

 ҈㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-96

Physics

Þ r├� ҈㡰졔r犨� ҈r犨�맔 ҈㡰㦨r犨� Þ 맔҈맔҈졔҈맔҈맔 ҈҈맔҈맔҈㦨҈맔 ҈맔  Þ ҈ ҈ 㡰㦨 \ ҈ 㦨  㡰 ᨨ鼀⼄ 矄 ҈㡰 㡰 ҈㦨�  㦨

\

 ᆠ   矄�ᨨ  ᨨ   矄� �犨   � �矄 �  ⼄盐���盐鼀 �矄

 = ҈

҈ � � = =   

㡰 V҈㦨 ᨨ鼀�ᨨ盐鼀ᨨ ᆠ泐� �ᆠ矄  V㦨ᨨ� 矄� ᨨ盐鼀ᨨ ᆠ泐� �ᆠ矄  y㦨 ᆠ�ᨨ ᨨ Vᨨ盐鼀 � 犨� 犨

ᨨ犨��  㦨  盐矄 ᔴᨨ ��ᨨ  ᨨ  ᨨ�ᨨ 㡰

҈

æ V҈ + V ö ÷  ҈㡰g è  ø

\

V҈rc g졔 yV㡰 ҈㡰g㦨 ç

ᨨ

V y㦨�졔 �rc㡰 ҈

҈鼀



㝐� æ 꾀s ö ç҈ ÷ ├ è 㝐 ø

V

和ᨨ�  rc�   y>� 㡰 盐├鼀ᨨ 盐盐矄

h

㦨



 ´ ҈㡰 ´ g = M ᆠ盐 g ҈

㡰 ᨨ鼀 꾀ᆠ �鼀 矄� ᆠ�  盐矄㦨 犨 ᨨ  盐�  �矄ᆠ Fᨨᨨ鼀Fᨨ㦨Vrg Þ Fᨨᨨ鼀㦨Fᨨ졔Vrg 

æ V ö Mg = ç ÷ rwg è � ø æ M ö rw rw ᨨ ç ÷ = ᨨ r = � èV ø � ␔   ᨨᆠ├ ᨨ矄 盐泐�  犨 ᨨ�  

a ᆠᨨ矄a

矄� a  矄� a

҈䰘

矄� a



\ R ᆠᨨ矄 a + R 矄� a 㡰d g

= R ᆠᨨ矄 a - R 矄� a 㡰d҈ g d҈ ᆠᨨ矄 a + 矄� a ҈ +  a = = Þ d  ᆠᨨ矄 a - 矄� a ҈ -  a

҈

 꾀� = 㝐� 

᲼Q鼀矄矄㦨  矄�泐맔ᨨ盐鼀桌

 Þ ├  = 㝐� - s 꾀� 

Þ  =

㝐� -

s꾀�  = 㝐� æ҈ - 꾀s ö ç ÷ ├ è 㝐 ø ├

㡰 ␔�� ᨨ ᆠ泐� 㦨 盐 盐矄 盐 ᨨ 盐 �⼄盐� 졔盐 盐矄 盐 ᨨᨨ犨�⼄盐� 

b㡰 矄矄盐 �  �鼀 ᔼ  B㦨矄矄盐� �鼀ᔼᔼA hr҈g㦨hrg Þ r҈㦨r  ᆠ 矄ᆠ� �ᆠ ��泐 ᨨ  �⼄盐� ᔼᔼ㦨sp��泐ᨨ �⼄盐� ᔼ㦨҈҈ 㡰

h P҈ ᔼᔼ A

h P ᔼ B

 æ  ö ç- ÷   è  ø æ Dl ö Þ = - Þ ç ÷ =    è l ø

꾀矄犨├ ᨨ犨盐├鼀ᨨ 盐矄  =

ᆠ㡰 ᨨ鼀 ��盐 ├  +  = 㝐�

├  + s

V

æA ö æ Aö æ  ö æ Aö æ L ö D ç ´ L ´ g ÷ = d ç ÷ ç L ÷ g + d ç ÷ ç ÷ ´ g è � ø è ø è� ø è �ø è  ø �d \ D㦨 





h

㦨rg᲼pRh졔V桌

V  æV ö rV 㡰 g = ç ÷ rᨨ� g + rwg ᨨrᨨ�㦨 rw = rw  èø � ᆠ㡰 矄矄盐�  ᆠ꾀鼀盐矄矄鼀 ᨨ鼀ᨨ  矄� 矄ᨨ � ⼄盐���盐鼀 d



㦨P҈맔A졔Vrg 㦨 hrg㡰맔 pR㡰졔Vrg

҈

a

҈҈

҈�

ᆠ㡰

Mg = Fb҈ + Fb

҈

㡰 ␔    ᆠᨨ�  矄 ᨨ鼀   ᨨ ᨨ  ᨨᆠ├ � ᨨ犨   ᨨᆠ├ 鼀ᨨ矄 盐犨 矄 ᆠ盐矄   犨��  ᨨ  ᨨ� � ᨨ 泐 ᆠᨨ鼀矄矄矄   ᆠl ᆠ矄矄꾀矄ᨨ�犨� �矄ᆠᨨ盐鼀 ᨨ  犨 ⼄盐ᨨ �矄 ᨨ犨  ᨨ盐鼀 犨 矄 犨   � �矄 ᨨ    ᨨᆠ├ � �矄ᆠ矄 鼀ᨨ ᨨ盐鼀    ᨨ ᨨ犨  ᨨ盐鼀 ᆠ盐矄  矄�泐ᨨ ᆠᨨ� �矄�    矄�泐ᨨ 犨 ᆠh犨�矄ᨨ ᆠ矄

 �㡰

鼀 鼀矄矄矄 ᨨ盐 ᆠ  

 ��㡰 �㡰맔 ҈㡰맔g㦨 Mᆠ盐졔m㡰g 和盐ᆠ� �⼄盐�ᨨ  �㡰 ᨨ鼀⼄盐�ᨨ  ��㡰犨� Þ 鼀�㦨 �㡰맔� ҈㡰㦨҈�맔䰘맔҈ � Þ 鼀㦨䰘�├� 黨

҈ b㡰 ␔  ᨨ 泐 ᨨ矄   犨�� ᨨ  ᨨ 泐㦨盐 盐矄

\ �㡰 ´

҈҈� ´ ҈� - ҈҈ ´ ҈� 㡰 D = 㦨҈��맔҈� D ⏌  ҈

⧤ 

㝐�

æ - ö l æ r� ö l Dl = ç ÷ =ç ÷ è  ø è  ø =

҈ ´ ҈ ´ � ´ ҈ 黨

䰘 ´ ҈

҈ ´ =  ´ ҈ - 

\ Dl 㦨鼀鼀 ; 鼀鼀

WWW.JEEBOOKS.IN

PS-97

Mechanical Properties of Fluids ҈黨

K㦨

-DP DV ⏌ V

Mg DV Mg \ = A V AK V f - V� 㡰 Mg V� - V f Mg Þ  Þ  = = V� AK V� AK     pR - p R - d R 㡰 Mg  Þ  =   AK pR  dR Mg R - ᲼ R - R dR桌 Mg = Þ =  Þ   R  AK AK R 矄 ␔   ᨨᆠ├ᨨ �ᆠ鼀矄  矄 ᨨ犨�盐�鼀泐矄� ├�

 犨␔   矄 ᨨ矄� ├矄 �犨� �矄ᆠ犨⼄盐ᨨ �矄 ᨨ犨  ᨨ盐鼀 盐 犨     矄 ᨨ 犨矄 鼀   �  �ᆠ � �矄ᆠ  鼀ᨨ ᨨ盐鼀 ᨨ  犨    �矄 ᨨ犨  ᨨ盐鼀 ᆠ盐矄 d >d犨 DP 㦨

犨 



Q ᨨ盐鼀㦨 ҈





㦨

GMr R P

\

k WFS R r

pRrg pRrg ᨨ x = Þkx =  k �

ᆠ㡰 d   矄�泐ᨨ  鼀�ᨨ  矄  ␔�� ᨨ 矄  㦨  盐矄 盐ᨨ�졔  盐矄 盐ᨨᨨ� Vdg㦨

V V d � g + dᨨ� ´ g  

Þ d㦨 

d� + dᨨ� 

=

҈ +  = 䰘� ⏌ ᆠ鼀 

bᆠ㡰 ␔   ᨨᆠ├ᨨ 鼀矄矄m�矄 A � 矄�  �⼄盐�  盐 盐矄FT犨�ᆠ ᨨ    鼀矄矄 犨 �ᆠ  犨� ᆠ矄   m  � �ᨨ A�犨� 矄矄  ├� 꾀ᆠᆠᨨ � �ᨨ犨ᨨ Ἐ矄 � 犨ᨨᆠ F F   泐 ᆠ�ᨨ    �矄 ⼄盐  B ᨨᨨ矄� ᆠ�ᨨ  和ᨨ泐ᆠ�ᨨ  ⼄盐 ᨨᆠ犨�  ᨨ  �⼄盐� ᨨ   ├犨 �ᆠ 犨�� ᆠ矄   � ��  B� 犨�  鼀ᨨ   �├� 㡰 犨 ᨨ矄泐矄鼀 矄 泐盐 ��泐 矄ᨨg㦨  꾀ᆠᆠᨨ � � ᨨ꾀ᆠ �鼀 矄 � ᆠ�  盐矄 㦨 犨��  ᨨ  盐�  �矄ᆠ 㦨 鼀矄矄ᨨ  盐�  �矄ᆠ 㡰맔g \  盐矄 㦨  ᆠ㡰 ᔴᨨ 矄�   ⼄盐���盐鼀ᨨ  犨ᨨᨨ   ᆠ泐� �ᆠᨨᆠ├ ᨨᆠ矄ᆠ� ��   ᨨ犨 犨  �ᆠ�ᨨ   T

䰘



r p㡰dr

GM r



r

ò rdr

R R

졔 

 W 㦨 p  r 㡰 ´ h ´





 = p ´  r

GM r é   ù R -r \ P㦨 û  R ë é  黨R  ù  êR  ú 䰘R ҈ úû P  =  ⏌ 㡰 êë  = = ҈ = \   P  =  ⏌ 㡰 é   R ù �R  êR  ú 黨 黨 ûú ëê  é  黨R ù êR  ú � ûú ҈ P  =  ⏌ �㡰 ëê = =   P  =  ⏌ �㡰 é  R  ù ҈ êR  ú � ûú ëê 

   pR rg  pRrg  

 㡰 ᆠᨨ鼀矄泐矄鼀�矄矄矄 ᨨ犨 �  ��盐 x  ᨨ ��ᨨ ᨨ  矄� � 꾀⼄盐���盐鼀 ᨨ盐 矄  W졔 FS㦨FB

r

R r



T

P҈ ´ p r 㡰

�㡰 ␔�� ᨨ 犨ᨨᨨ   ᆠ泐� 

 ò dp = 

Þ kx㦨

鼀矄矄   ᆠᨨ 犨犨�   矄�泐

矄 ␔   鼀盐 �矄 � ᆠ矄     矄�泐 ᨨ  鼀ᆠ盐泐 r㡰 ᆠ矄矄矄rt㦨r ҈gt㡰   ᆠ ᨨ 鼀ᆠ盐泐�

ᨨ鼀盐 㡰� ᆠ矄矄 Q hr 㦨 ᆠᨨ 矄  矄

ᨨ 犨犨�鼀�  矄鼀�  ᨨ  ␔     鼀  � ├矄 矄ᨨ鼀 犨 ᨨ鼀  ᨨ  �矄 犨��  � ᆠ矄矄   ᨨ ᨨ犨�矄� ├ 盐 꾀  �矄矄� ├� � ᨨ    ᨨ 犨� �矄ᆠ   矄鼀 ᨨ盐鼀 ᨨ  犨 �  ᨨ  矄 盐 ├泐鼀  bᆠ㡰盐矄ᆠᨨ 矄�  鼀 鼀矄矄 鼀矄 ᨨ犨 �  矄   ᨨ�ᨨ  ᨨ    ��盐 Pp P졔dP㡰pr

FB

   pR rg졔kx㦨 pR r㡰g  

r ´g 

hr g 



P

W

P

��㡰 ᨨᆠ 盐 ᨨ矄矄盐 P҈㡰 ᆠ  泐 �⼄盐�  ᨨ  ��  h ҈ ᨨ  犨ᨨᨨ  ᨨᆠ├ F҈ 㦨P҈맔p r㡰㦨᲼P졔h҈rg桌맔p r㡰 ���㡰 ᨨᆠ ᆠ� �ᨨ    盐犨  �ᆠ�ᨨ  盐 ᨨ 矄矄盐 P     ᨨ鼀ᨨ犨 犨ᨨᨨ  ᨨᆠ├ 鼀ᨨ矄 �ᆠ矄矄盐 F = P ´ p é r 㡰 - r  ù + P ´ p r 㡰 

ë û  = [ P + h҈ + h 㡰rg ] ´ p ´ r  + P pr 

ᔼ 矄�盐�ᨨ ҈ �ᨨ �矄� � ᨨᆠ├F = F҈졔W

[ P + h҈ + h㡰rg ] ´ ( p ´ r  ) + pr  P = [ P + h҈rg ] ´ pr  +

黨

�h p ´ r  hrg ᨨ h҈ =  

b㡰 꾀�� ᆠᨨ 矄� � �⼄盐���盐鼀ᨨ 犨ᨨᨨ  ᨨᆠ├

ᨨ ᨨ犨 犨  ᨨᆠ㦨 ᨨ ᨨᆠ 盐犨 矄 ␔ ᨨ ᨨᆠ├졔 ᨨᆠ 盐ᨨ鼀ᨨ矄 �ᆠ矄矄盐㦨 ᨨᆠ 盐ᨨ 矄矄盐 ᨨ  �⼄盐� 졔 ᨨᆠ 盐 ᨨ鼀ᨨ矄 �ᆠ 矄矄盐

r p ҈r  㡰 ´ g + P p ´ ҈ r  㦨᲼hrg졔P桌p᲼ ҈㡰r桌  졔P맔r

WWW.JEEBOOKS.IN

EBD_8341 PS-98

Physics

犨  h㦨 �� ᨨ  犨� 矄�盐�ᨨ  ᨨ犨 �ᆠ   ᨨᆠ├ 鼀� 矄 �  �矄 ᨨ��� ᨨ矄��ᨨ 

 ᆠ犨  矄ᨨ 矄盐� 犨 ᨨ 犨 矄 

 \ h㦨 h 黨



҈

 g + l d 犨ᨨᨨ g = l d 犨 g

㡰 ᔼ 矄�盐�ᨨ 犨    �� hᨨ 犨�矄 盐  ᆠ矄       盐犨  ᨨᆠ ᆠ� � ᨨ    犨ᨨᨨ   ᨨᆠ├ ᆠ矄矄  ᨨ ᨨᆠ ᨨ犨 犨 鼀� 矄   矄鼀 �矄 �  ᆠ 犨� ᆠᨨ鼀 矄 泐  ᨨ鼀 ᆠ�ᨨ  泐   ├犨ᨨ  犨ᨨᨨ  ᨨᆠ├ ᆠ ᨨᆠ├ ᨨ矄 ᨨ鼀ᨨ矄 盐 鼀� 矄�矄ᨨ��� ᨨ矄��ᨨ  㡰 꾀矄  泐 ᨨ矄�ᆠ ᨨᆠ  泐�⼄盐� 꾀ᨨ  ᆠ泐�  ᨨ鼀 矄� 矄 泐ᆠ ᆠ矄ᨨ盐   盐�矄 ᨨ b㡰 ᔼ  ⼄盐���盐鼀 盐ᨨ泐  ᨨᆠ㦨 犨�� ᨨ   ᨨ 泐 Þ hArAAg졔hBrB Ag㦨 hA 졔 h 졔 hB㡰ArC g 犨  rC 㦨  矄�泐 ᨨ  ᆠ泐� 㡰

æ hAr A + hB rB ö ÷ - hA + hB 㡰 rC è ø

 矄� ᨨ �ᨨ ᆠ盐 l ␔  鼀矄矄m㦨��矄ᨨ   ᆠ盐ᨨ 犨ᨨᨨ

Þ l d 犨ᨨᨨ = l d 犨 -   �㡰 ␔   鼀矄矄m㦨��矄鼀ᨨ

l d 犨ᨨᨨ = l - 㡰 l d 犨  ��㡰 ᨨ鼀⼄ �㡰  ��㡰

l d 犨 -  = l - 㡰 l  d 犨 Q  d 犨 = ҈ 㡰

l -  = l  l - 㡰  Þ l = ҈ ᆠ鼀

\

h㦨 ç

�

泐 �矄 ᆠx ᆠᨨ盐鼀 ᨨ  鼀ᆠ盐泐 �矄ᆠ 

和盐矄�盐� �盐ᨨ hAhBrArB re 矄ᨨ� �犨�h 㦨�ᆠ鼀 ᆠ㡰 ᆠᆠ�ᨨ a㦨

A

F盐ᨨ泐  - Mg

p1

M

mg

҈鼀

q

�鼀

├� �鼀ᨨ鼀  ᨨ盐ᨨ�  O

Þ p㦨

 �㡰

꾀矄ᨨFT㦨犨ᨨ  盐�  �矄ᆠ 㦨 ᲼ l - x 㡰 A桌 ´rw g  ��㡰 꾀 m 㦨 l A㡰 �rw  ���㡰 ␔ A�矄 ᨨ ᆠᨨ矄矄矄ᆠ�ᨨ ᨨ  ᨨ  ᨨ鼀⼄ �㡰 ��㡰  ���㡰



 Vl  Vs㦨ᨨ盐鼀ᨨ �⼄盐�  矄ᨨ 矄ᆠ�泐 dl  ds 㦨  矄�泐 ᨨ  �⼄盐�    矄ᨨ  矄ᆠ�泐 ␔     矄ᨨ 矄 犨 �    ᨨ   犨��  ᨨ  矄ᨨ 矄 犨  ᆠ  泐  盐ᨨ泐  ᨨᆠ

� ´ 䰘d � ´ g � - x

 ��㡰

Þ p҈졔҈d�맔g㦨p

 ���㡰

ᨨ鼀⼄ �㡰 ��㡰  ���㡰

� ´ 䰘 ´ d � g

� + x

� � =  \ q 㦨� ҈ - x 䰘䰘

和� ᆠds> dl  \Vs Vl

 �㡰

p҈맔A졔҈맔A맔d�g㦨p맔A

l æ l - xö 矄� q 㦨 ᲼ l - x㡰 A桌rw g ´ ç 矄� q è  ÷ø 

Vsds㦨 Vl dl

� ´ 䰘d � ´ g � + x

M�矄 鼀� 㜠ᨨ� ᨨ 盐AB. 꾀 ⼄盐���盐鼀 p҈맔A졔mg㦨p맔A

 l = ҈ 鼀 \ ҈x㡰㦨�Þx㦨黨鼀 ᨨ鼀  ��鼀

ᆠᨨ矄 q =

B

ᨨ�矄 � ᆠᨨ盐鼀 턼 p 맔�맔A㦨p맔 �x㡰맔A

O

 l A㡰 �rw g ´

45 cm

B

Þ p҈㦨

鼀�

l æ l - xö 矄� q mg ´ 矄� q = FT ç è  ÷ø 

Q

꾀 ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ ᨨ  盐 x �矄 ᆠ ᆠᨨ盐鼀 ᨨ 鼀ᆠ盐泐 �矄ᆠ �  盐�矄   �ᆠ泐 꾀泐� � P҈V҈ 㦨 PV ᨨ�矄 � ᆠᨨ盐鼀 꾀 p맔�맔A㦨p҈맔 �졔x㡰맔A

x

q

M

Q'

p2

45 cm

P

10 cm 10 cm

ᔴᨨ 矄�  ⼄盐���盐鼀ᨨ   ├ � � ᨨ� �졠 ᨨ⼄盐���盐鼀F 㦨 t 㦨



P'

M

é hAr A + rB h + hB 㡰 - h + hA + hB 㡰 rC ù 㦨 ê ú g rC h + hA + hC 㡰 ë û g 㦨 盐犨 矄  

x

A

Þ

+ ҈ d � ´ g =

� ´ 䰘 � ´ 䰘 + ҈ = � + x � - x

� ´ 䰘 ´ d � ´ g � - \ 㦨黨�ᆠ鼀

Topic-2 : Fluid Flow, Reynold's Number and Bernoulli's Principle ҈

㡰 矄� �  ᨨ盐�Ἐ矄 ⼄盐�ᨨ

҈ ҈ P҈ + ru҈ + rgh҈ = P + ru  + rgh  

WWW.JEEBOOKS.IN

PS-99

Mechanical Properties of Fluids



ᨨ ᨨ� ᨨ �h҈㦨 h㦨 ├� �

҈҈ 㦨 

P P҈㦨PP㦨 犨� 

p   � 㦨 p   

҈ P ҈ P ҈ ҈ Þ P + ru  = + rV  Þ + ru = rV        P Þ V = u + r b㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ AaA㦨 ᆠ鼀  BaB㦨ᆠ鼀 ᨨᆠ�泐ᨨ �⼄盐�  ᨨ犨A㦨VA B㦨VB 矄� �⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐aAVA㦨aBVB VA㦨VB Þ VA㦨VB ᨨ犨盐矄� � ᨨ盐�矄⼄盐�ᨨ

҈ ҈ ҈ PA + rVA = PB + rVB Þ PA - PB = r VB - VA   

(

 

� 㦨  

和盐矄�盐� � 盐ᨨ � ⼄盐�ᨨ  �㡰

� 졔 � 㦨 � ᨨ =  é  ù  ê + ú  ë û 䰘

㡰 �ᆠ鼀



x

�

( DP ) ´  = ( 䰘 ) ´  鼀⏌矄 = ҈䰘 ´ ҈ ᆠ鼀⏌矄

҈� ҈� ᨨ盐鼀 ᨨ犨턼㦨aB맔vB 㦨맔҈맔VB㦨䰘ᆠ鼀⏌矄»䰘ᆠ鼀⏌矄 㡰 ᨨ鼀  ⼄盐�ᨨ  ᨨ ᆠᨨ � 盐�泐 A҈v҈㦨 Av v҈ v   ᨨᆠ��矄犨ᨨ 矄 ᨨ  � 꾀҈ 꾀   ᨨ � 犨ᨨ 矄



v҈ A p 㡰 黨 = = =  ҈ v A҈ p 㡰 b㡰 矄� � ᨨ盐�矄⼄盐�ᨨ

Þ

\   - ҈ = �  ҈㡰 꾀ᆠᆠᨨ � � ᨨ  ⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐泐

҈ P + v҈ - v 㡰 + rgh = P 

Þ v = v҈ +  gh Þ v = v҈ +  gh

꾀҈҈ = 꾀   꾀҈  鼀鼀 = 꾀  ҈ 鼀鼀 

쟼⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐�泐 꾀҈҈ 㦨 꾀

ᨨ鼀⼄盐�ᨨ  㡰

æ ҈� ö  ҈ᆠ鼀㡰 ҈鼀⏌矄㡰㦨 꾀㡰 ç ҈㡰 +  ´҈ ´ ҈ ÷ è ø ҈  맔҈㦨꾀 맔

ᨨ   =

 ҈ ҈



éQ � = ҈鼀 ⏌ 矄  = ҈ ᆠ鼀 ⏌ 矄  ù ê ú êë = � ᆠ鼀 úû ҈ 和ᨨ� �犨� ҈ = 

䰘 = p    = ( p´  ´҈  ) ´ �  䰘 ´҈ 䰘 Þ � = Þ � =  p p

 ᨨ 犨 �ᆠ 犨 ᨨ犨矄 ᨨ盐�  

䰘 ´ 䰘 䰘 ´ 䰘 Qp =҈ ) Þ = » 鼀 (  ´  ´҈  ´  ´ 

�    ᨨ    ᆠ  ᨨ    ᨨ � � ᨨ鼀    ᨨ 犨�   ├�矄ᆠᨨ矄ᨨ鼀 㡰 꾀ᆠᆠᨨ � � ᨨ  ᨨ盐�Ἐ矄 � ᆠ�

҈  ҈ r ҈ 졔 r � 㦨 r   

҈ 졔 � 㦨  � 졔 � 㦨  

꾀҈    = = 꾀  ҈ ҈

æ ö   ç ҈ ÷ - ( ҈ ) =  ´҈ ´ � è ҈ ø

b㡰 ᨨ盐鼀�ᆠ ᨨ犨

Þ � =

 㡰

盐� � �矄盐ᨨ � ⼄盐�ᨨ  ҈㡰

㦨



 � ᨨ  �ᆠᨨ盐鼀 ᨨ鼀ᆠ盐泐�  盐�矄 P졔x㦨P Þ P㦨 䰘x㡰 Þ 맔A맔䰘㦨 䰘x㡰맔꾀맔 �x㡰 \ x㦨

盐矄 � ᨨ �ᆠᨨ盐鼀

㦨�㦨҈ᆠ鼀 㡰 꾀ᆠᆠᨨ � � ᨨ  ᨨ盐�矄  ᨨ鼀

҈ ҈ ҈ + r҈ =  + r  

҈- \ 꾀 㦨 㦨�맔҈�鼀  

�

�x㡰

)





P

ᆠ鼀

æ ҈ V ö V  Þ DP = ҈ çVB - B ÷ Þ DP = � ´ B ç   ÷ø  è

 Þ VB =

҈



盐㦨 꾀҈҈ = 꾀    = 黨

 ´ ҈ = 䰘�ᆠᆠ ⏌ 矄 

㡰 ᨨ鼀 ᨨ盐�Ἐ矄 ᨨ鼀ᨨ� ҈  h

҈



 �㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-100

Physics

҈ rV҈ 

㦨졔졔

҈ rV 

P졔rgh㦨P҈

 �㡰

꾀 ⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐A҈V҈㦨AV ᨨ

V㦨

A҈V҈ A

҈

҈҈

҈

L p

҈�

҈

\ P㦨�Pa ᆠ㡰 �矄ᨨ  �矄盐矄  矄 v҈㦨�鼀⏌矄 �ᆠᨨ鼀矄ᨨ盐ᨨ  ᨨ 犨�  矄 v ᨨ鼀 � ᆠ� ᨨ  ᆠᨨ � 盐�泐 a҈v҈㦨av Þ

  pr҈ v҈ = pr v Þ r҈ v҈ = r v

Þ

(  ) ´ � = (҈) ´ v

\

v㦨鼀鼀矄҈㦨鼀矄҈

㡰 PX - PY =

҈ ra va 

X

Y Z



\

҈ ҈ rl vl = ra va Þ vl =  

\

ᨨ盐鼀 ᨨ犨 µ

ᨨ鼀 ⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐�泐

和   =  ´ 和 - 和 㡰 =  ´ 和 ҈䰘

 ��㡰

ᨨ鼀⼄矄 �㡰  ��㡰

 -  =

҈

ra ´ va rl

ra rl

㡰  ᨨ盐鼀 ᨨ犨  Q㡰 ᨨ    � ᆠᨨ鼀矄矄� 盐�  �

矄 泐 ᨨ犨 鼀� 矄 ᆠᨨ 矄  ᨨ鼀 ⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐�泐 av㦨ᆠᨨ 矄  \

� 鼀鼀

҈

v A㦨�ᆠ鼀

A҈㦨҈ᆠ鼀

盐 PZ㦨PX

 ҈ æ ҈  䰘 ö ҈ 䰘 r ç  -  ÷ = r  = r \ 㦨黨 ø  黨  è黨  㡰 ᔼ ��泐矄矄盐 ᨨ � ᆠᨨ盐鼀

P҈ = ҈� N ⏌ m ᨨ犨 P҈ 㦨 ҈� 鼀    V҈ = � - H 㡰 A ᨨ盐鼀 V҈ = � - H 㡰 A 犨  A�矄 ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ ᨨ   H 矄矄 � 泐 ᨨ盐鼀ᨨ �ᆠᨨ盐鼀 ᨨ 犨V㦨 �㡰꾀㦨꾀ᔼ P �矄 矄矄盐 ᨨ � 

ᔼ ��泐



v҈㦨҈鼀矄

和 和

  

P

҈ PZ - PY = rl vl 

 �㡰



Þ=

P҈㦨Pa

҈ = P + ´҈ ´   

҈ ҈  + r =  + r   ҈ r  -  㡰 

\ �  �� ᨨ 犨 盐ᨨ ᨨ � �ᨨ ᨨ� �ᆠ㦨 㦨鼀鼀 꾀ᆠᆠᨨ � �ᨨ ⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐�泐 A҈v҈㦨Av Þ ҈맔҈㦨�맔v Þ v㦨鼀⏌矄 ᨨ犨盐矄� � ᨨ盐�Ἐ矄 ᨨ鼀

҈ Þ  + ´҈ ´҈  

ᆠ㡰 ෌� v҈㦨҈鼀矄҈ A҈㦨҈鼀 v㦨ᨨᆠ�泐ᨨ 犨矄鼀҈�鼀ᨨ犨  A㦨䁸 ᨨᆠᆠ盐� �v 盐矄� � vu㦨as u㦨҈鼀⏌矄錐s㦨҈�鼀a㦨g㦨҈鼀⏌矄  v㦨v㦨䁸 v҈㦨맔҈맔҈� Þ v㦨v㦨鼀⏌矄 泐⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐v҈A҈㦨 vA v A ҈ ´ ҈ - = � ´ ҈ -� m \ A㦨 ҈ ҈ = v  黨㡰 꾀泐� �  ᨨ盐�Ἐ矄 ⼄盐�ᨨ

 -  =

� 泐

҈ ҈ P҈ + rv҈ = P + rv  

 gy 㡰 ´ L =  g ´  y 㡰 pR  R㦨

P = 黨 ´ ҈ N ⏌ m 

\  ҈� ´ � - H 㡰 A = 黨 ´ ҈  㡰 ´  A Þ 㦨鼀鼀

㡰 꾀矄犨├ ᨨ犨ᨨᆠ�泐ᨨ  盐 V㦨 gh ᨨ鼀⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐A҈V҈㦨AV

Þ

\

V =  A

PV ҈ ҈ = PV

 ��㡰

Q h =  - ��  = 䰘� 鼀 㡰

L㦨pR\

P + ҈ ´ ҈ ´

꾀矄矄盐鼀� �  鼀盐鼀� 矄 ᆠᨨ 矄 ᆠᆠᨨ � �ᨨᨨ泐矄犨

ᨨ鼀⼄ �㡰 ��㡰  gh  ´ ҈ ´ 䰘� v㦨 ᨨ v㦨 㦨�鼀⏌矄  ҈ - ҈㡰  æ aö ҈- ç ÷ è Aø

҈

P

 = ҈� ҈

\

 鼀鼀

졔rgh졔

Q㦨a맔v 㦨ᆠᨨ 矄 ᨨaµ

҈ v

犨 a㦨ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ  v㦨ᨨᆠ�泐 Þ ᔼ v ᆠ矄矄a� ᆠ矄矄 �ᆠ㜠矄 ␔   矄鼀 ᨨ  犨 鼀ᨨ矄 盐 �矄 矄  v㡰 ᆠ矄矄    ᨨ �a � ᆠ矄矄 �   犨 矄 矄 ᨨ盐 矄  ᨨ盐 �  ␔   矄鼀 ᨨ  犨 ᨨ鼀 ᨨ矄 � 鼀ᨨ矄 ᨨ犨  �矄 矄 � ᆠ矄矄   ᨨ ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ  ᆠ矄矄 ෌� A҈㦨p맔 맔҈鼀㡰 A㦨p맔 ҈맔҈鼀㡰 v҈㦨�鼀⏌矄

WWW.JEEBOOKS.IN

PS-101

Mechanical Properties of Fluids v҈

A



A ´L´D´g H H � P㦨P졔 dg + ´ d ´ g +   A �d ù é æ H L ö + ÷ dg  êQ D = Þ P㦨P졔 ç  úû è  ø ë  b㡰 �㡰 꾀泐� �  ᨨ盐�Ἐ矄  ᨨ鼀 éH ù æH ö P졔 ê ´ d ´ g + ç - h÷ d ´ g ú è ø  ë û

v

h

x ᨨ鼀⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐A҈v҈㦨Av \

v㦨

H - h㡰 ҈  g 㦨P졔  d 㡰v  Þ v㦨   ��㡰 ᨨ�ᆠ鼀ᨨ�ᨨ ᨨ �⼄盐�  � � ᨨ鼀 ᨨ�鼀├ ᨨ ᆠ   �⼄盐�  ᨨ ᨨᨨ鼀 uy 㦨Sy㦨hay 㦨gty㦨t

A҈ p ´  ´ ҈ - 㡰  ´ � v҈ 㦨 㦨鼀⏌矄  A p ´ ҈ ´ ҈- 㡰

ᨨ鼀 h㦨

h ҈  gt  Þ t㦨 g 

S㦨ut졔

 ᆠ ᨨ� ᨨ  �

h  ´ ҈� = ´ = 鼀 g ҈

x 㦨v맔t㦨v ҈黨

෌� r㦨҈├�⏌鼀h҈㦨鼀h㦨�鼀 A҈㦨맔҈鼀A㦨맔҈鼀v҈㦨҈鼀⏌矄 ᨨ鼀 ⼄盐�ᨨ  ᨨ  ᆠᨨ � 盐�泐

H  H 㜠h 

A҈v҈ = � 鼀⏌矄 A҈v҈㦨Av \v㦨 A

v

  ᆠ  ᨨ쟼

꾀泐� � ᨨ盐�Ἐ矄  ᨨ鼀  P   Q p҈p㡰㦨rg hh҈㡰

x = v × t 㦨 H - h㡰

dx 㦨 dh dx ҈ = ᲼Hh㡰h桌҈⏌{Hh晤 dh  ҈ H ᲼ Hh㡰桌҈⏌᲼Hh桌㦨 Þ h㦨     ᆠx犨�鼀 �鼀盐鼀h㦨  

҈ ҈  ù    é҈   꾀 r v - v҈ 㡰 = ´ ҈ ê - ҈ú = - ´ ҈ ⏌鼀    ë û 㦨䰘�맔҈⏌鼀 \ ␔ᨨ├ ᨨ ⏌ᨨ泐矄矄盐 ҈㦨黨맔҈䰘�맔҈⏌鼀㦨黨�맔҈⏌鼀 㡰 �㡰 和� ᆠ ᆠ泐� �矄� ⼄盐���盐鼀�  �⼄盐� \ ␔�� ᨨ ᆠ泐� 㦨盐 盐矄 盐ᨨ盐�⼄盐� 졔盐 盐矄 盐ᨨᨨ犨�⼄盐�

d L 

A⏌� F D

d

鼀 �鼀盐鼀盐ᨨ x

é æ  H ö ù H xm㦨 êH -  ç è  ÷ø úû  ë

H⏌

 㦨

H⏌ A

҈ H H  H  H ´ = =    

Topic-3 : Viscosity and Terminal Velocity

mg

L 

Pᨨ h x

g h ´ 㦨 H - h 㡰 h g  ���㡰 ᨨ � � � 盐ᨨ h ᨨ犨 �ᆠ x�矄鼀 �鼀盐鼀

҈ r v - v҈ 㡰 

ᨨ犨 犨ᨨ├ ᨨ ⏌ᨨ 泐��泐 ᨨᆠ矄 㦨rg hh҈㡰㦨҈맔黨맔㦨黨맔҈⏌鼀



h ҈  ҈  at Þ h 㦨 gt Þ t 㦨 g   Pᨨ

҈

㡰 矄� �vu㦨gh

Þ v  -  =  gh Þ v =  gh A A L A L ´ L ´ D ´ g = ´ ´ d ´ g + ´ ´d ´g � �  � 

d d �d + = Þ D㦨    ��㡰 ᔴᨨ 矄� � � �ᆠ ⼄盐���盐鼀 ᨨ  犨ᨨ �⼄盐� 矄     ᆠ泐� 

ᨨ 矄矄盐    ᨨᨨ鼀 ᨨ    ᆠ泐�  㦨 꾀鼀ᨨ矄 �ᆠ 矄矄盐졔矄矄盐 盐ᨨ�⼄盐� ᨨ   矄�泐d졔矄矄盐 盐ᨨ �⼄盐�  ᨨ   矄�泐d졔矄矄盐 盐ᨨᆠ泐� ᲼␔�� ⏌꾀桌

鼀�  ᨨᆠ�泐

VT =

 r  r - s 㡰 g h 黨

꾀  � � ᨨ盐� h ᨨᆠ�泐矄 ᨨ盐 ⼄盐ᨨ鼀�  ᨨᆠ�泐

\  gh =

 r  r - s 㡰 g 黨 h

WWW.JEEBOOKS.IN

EBD_8341 PS-102

Physics

Þh= 

r  g r - s㡰 ҈h

㡰 䰘맔

�� � �⼄盐�ᨨ  ��㡰泐 �㡰

 r  g  r - s㡰 ҈ h

Þ  gh =

҈ R = Þ R҈ = R  R҈

Þ h a r

    pr 㦨 pr  

ᨨr㦨

鼀� ᨨᆠ�泐 vµr

ᨨ盐鼀 V =

R  



v҈ r҈ \ v =  r  

 æ r ö æ R⏌ö ҈ ᨨ v㦨 ç ÷ v҈ = ç ÷ v҈ 㦨 黨 è R ø è r҈ ø





ᨨ

v҈ v 㦨黨

  = = 䰘 鼀 䰘 ´ ҈ ´ ҈� ´ ҈-

r  rs㡰g 黨h r҈ s - r҈ 㡰 g VP 黨h҈ r  s - r҈ 㡰 h =  = ҈ ´ VQ  r s - r  㡰 g r s - r  㡰 h҈ 黨h

�



᲼ - 桌  ´ = �㡰 ᲼ - ҈桌  ҈





r  r  s҈ 㡰 � 黨h҈

Q

r҈s㦨s҈r㡰

r1

҈ s1



r2

�  s2

҈

ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  矄矄盐� 矄� ҈矄 矄ᨨ盐

DP҈ = P҈ - P = ҈ =

T R҈

꾀  DP = P - P =  =

 �㡰

T R

 ��㡰

R=

T d  r㡰 g

b㡰 꾀矄 犨 ├ ᨨ犨  

㡰 ␔   盐�矄 ᆠ   盐ᨨ泐  ᨨᆠ㦨 ᨨᆠ 盐ᨨ矄盐 ᆠ 矄�ᨨ

q

꾀�� VPVQ�.e. ��矄VP VQᨨᨨ矄�ᨨᆠ ᨨ 

Topic-4 : Surface Tension, Surface Energy and Capillarity

R d  r㡰 g  Þ 

 ᆠᨨ矄 q = r�

� = 䰘�

␔ r� ᆠᨨ矄 q� ᆠᨨ矄҈�° ҈ = ҈  = = ᆠᨨ矄 q␔ ᆠᨨ矄 ° r␔  æ ö q �

ᆠᨨ矄 æ � ö r ␔ æ � ö =ç ÷ç ÷ç ÷ ␔ çè ␔ ÷ø çè r� ÷ø çè ᆠᨨ矄 q ␔ ÷ø ҈ ҈  = 䰘� ´ ´ =  = ҈ � 

r  s  r҈ 㡰 � 黨h

\

㡰 ᨨ  ᨨ矄ᨨ� ⼄盐���盐鼀盐犨  ᨨᆠᨨ  ᨨ㦨 ᨨ犨 犨  ᨨᆠ ᨨ  ᨨ

Þ T=



h VP = ҈ h VQ



   pR dg  pR rg     Þ T pR㡰 = pR d  r㡰 g 

␔ �矄 �盐矄ᨨ 矄  ᨨ犨 犨  鼀�  ᨨᆠ�泐

VQ =



T pR =

 㡰和� ᆠ矄� ��矄盐 r҈s҈ rs ᨨ ᨨ� � 犨��  ᨨ 矄泐矄鼀 㦨  盐 盐矄 r҈졔r㡰Vg㦨 s҈졔s㡰Vg 犨  鼀�  ᨨᆠ�泐

VP =

T ᆠᨨ矄 q rgr

 ´ � ´



VT㦨

 =

V҈ R҈ R  = =  = ҈ V R R

\

b㡰 ෌�  꾀 �ᨨ ᆠᨨ ᆠq㦨 和盐 ᆠ 矄�ᨨ T㦨�鼀҈  �盐矄ᨨ ᆠ�泐盐r㦨҈�鼀鼀㦨҈�맔҈鼀  矄�泐ᨨ 鼀 泐 �ᨨ � r㦨䰘├�鼀 ᔴ�泐�矄 h =

b㡰 꾀ᆠᆠᨨ � � ᨨ ᨨ�ᆠ�矄  ᨨ鼀 ᨨᆠ�泐ᨨ     V 㦨  gh =  ´ 黨 ´ � @ 黨 鼀矄 㡰 꾀矄 犨 ├ ᨨ犨 鼀�  ᨨᆠ�泐

  pR 

rq

T맔dl

ᨨᆠ 盐ᨨ ᆠ矄矄矄矄盐㦨 盐 盐矄 꾀ᆠᆠ矄矄矄矄盐� �盐㦨





T p R  rw g p r  㡰 = R T 

Þ r =

 R  rw g  rw g Þ r = R T T

WWW.JEEBOOKS.IN

PS-103

Mechanical Properties of Fluids 

㡰 꾀ᆠᆠ�ᨨ  盐 ᨨ ��泐ᆠ  �矄 犨�     

꾀ᆠᆠᨨ � �ᨨ� �矄⼄盐�ᨨ PV㦨nRT

ö æ �¢ = � ç҈ - ÷ è ø

PAVA㦨nARTB Þ

 p 㡰㦨nARTA  �㡰    PBVB = nB RTB Þ  ҈ ´ p 㡰 = n B RTB … ��㡰 

矄矄盐㦨r�  ᆠ�ᨨ 䰘

æ ö �矄 ç҈ - ÷ 泐 è ø



C

�� � �⼄ ��㡰泐 �㡰

R

a 

q 졔a b 

M

 ҈ ´ p 㡰 n   = B  nA ҈ ´ p 㡰  nB \ = nA

q

P

҈

S ö æ 꾀矄ᨨ ç P ÷ + hrg = P R ø è



Þ

hrg 㦨

S R

T= ҈҈

S S ᆠᨨ矄 ( q + a  ) = Rrg brg    ҈ pR = k ´ pr  \ R = K r 㡰  

é R ù  ҈⏌ \D㦨 ps ê k ´ ⏌ - R ú = pSR éëk - ҈ùû ë k û

҈ ´ ҈- 㡰  éë҈a ⏌ - ҈ùû p

\ ҈  = ҈ a ⏌ - ҈ �ᆠ� �

a =  \ a =   T 㡰 矄矄盐PA㦨P�졔 RA Q 쟼 ᆠ矄矄矄矄盐 盐ᨨ矄盐 ᆠ 矄�ᨨ  T㡰�  矄ᨨ盐

҈㦨҈a⏌Þ

҈

ᆠ鼀

ᆠ鼀 

T  ´   = +   Þ PA = ҈ N ⏌ m RA  T  ´  = + 和�鼀�泐 PB㦨졔 㦨҈⏌鼀  RB

\ 㦨 ҈ 鼀鼀㦨䰘҈ bᆠ㡰 ᨨᆠ矄ᔼ

 =

�㦨鼀

PA =  +

⏌

 ᆠᨨ矄 q҈  ´ 䰘� ´ ᆠᨨ矄 ° = = 䰘�ᆠ鼀 r �  ´ ҈- ´ ҈ ´ ҈

ᨨᆠ矄ᔼᔼ

B ҈ v

犨ᨨ 鼀҈ 䰘㡰꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  犨ᨨ �鼀矄 �矄ᆠᨨ  �ᆠ├ 矄矄Ἐ Ἐ � �矄鼀�ᆠ�ᆠ盐 �矄 㦨 ⏌ 矄矄盐 ᨨᨨ鼀ᨨ  �矄ᆠ㦨矄矄盐 盐 ᨨ 矄盐 ᆠ  矄�ᨨ

҈ =

㦨T⏌r㡰

A

rhrg ҈� ´ ҈-� ´ ҈� ´ ҈- ´ 黨 ´ ҈ = = ҈҈ 鼀��  

é ҈ ҈ ù ҈ ù 

é \r� = ê + = ú = ê + ⏌  úû ë ë ҈  û 



 ´ 䰘 ҈ ´҈ Þ  = Þ = = =  r� r� ҈ ´ ҈ ҈ ´҈

 a ⏌ - ҈ùû ᲼Q K㦨҈a桌 \D㦨 pSR éë҈

黨

᲼ᆠᨨ矄 q = ᆠᨨ矄° = ҈桌

æ ҈ ҈ ö r� = ç + ÷ è ҈  ø ҈ ҈ > \ ҈    㦨 ⏌



DU = S᲼k ´ pr - pR 桌

\҈㦨 p ´

T ᆠᨨ矄 q rgr

和盐 ᆠ  矄�ᨨ 

h=



[Q TA = TB ]

҈҈㡰 ෌�    �盐矄 ᨨ  ᆠ�泐盐 r㦨҈�ᆠ鼀㦨҈�맔҈�鼀鼀 h㦨҈�ᆠ鼀㦨҈�맔҈鼀鼀 矄� � h =

 R     �盐矄ᨨ    鼀 �矄ᆠ盐矄 ᨨ鼀 犨�   ᆠᨨ 矄   �q P 鼀ᨨ矄 �ᆠ矄矄盐 aö b æ b ᔼ Dᔴ㝐 ᆠᨨ矄 ç q + ÷ = Þ R㦨 aö ø R æ è çq+ ÷ ø è

\

҈맔

҈

 ᆠᨨ矄 q  ´ 䰘� ´ ᆠᨨ矄° = = 䰘�ᆠ鼀  r�  ´ ҈- ´ ҈ ´ ҈

ᆠᨨᆠ�ᨨ �   �� ᨨ 犨ᆠᨨ盐鼀 �矄 �  盐 盐ᨨ犨�� ᨨ 犨ᆠᨨ �  �  鼀 �矄ᆠ盐矄犨� �   ᨨ ᨨ  ᆠ矄矄 ᔼ ᆠ矄 ᔼᔼ�   ᆠ�泐ᨨ�  �矄�ᆠ鼀 ᨨ  犨矄盐 ᆠ    犨 �  ᆠ�泐 犨� ᨨ ᆠ    �  ᆠ␔ 犨� ᆠ ᨨ 泐�䰘�ᆠ鼀 s ᆠᨨ矄 q ᆠ㡰 꾀矄犨├ ᨨ犨 h = rrgeff ҈ 꾀矄�r� ᆠ矄矄h ᆠ矄矄hµ r ᲼ᨨ  鼀矄 鼀� � � ᆠᨨ 矄 桌

WWW.JEEBOOKS.IN

EBD_8341 PS-104

҈

Physics

꾀矄ᨨhµs 盐 � � �矄�ᨨ� �盐犨�  ᆠᆠ�ᨨ �a   g 㦨g졔a꾀矄g � ᆠ矄矄�h ᆠ矄矄 꾀矄ᨨhµ ᆠᨨ矄q ᨨhµq ᆠ㡰 �ᆠ ᨨᆠ 盐ᨨ矄盐 ᆠ  矄�ᨨ

q FV 㦨 T ᆠᨨ矄q㡰맔pr r

҈黨

\

q

 pr  T ærö  = T ç ÷ ´ pr = è Rø R

Þ ҈

Þ Þ 

ᨨ ⼄盐���盐鼀 ᨨ  犨� �  �ᆠ �ᆠ�ᨨ  ᨨ鼀  ᨨ 泐 ��鼀ᨨ  犨�矄 ᨨ犨 �   ��盐 T ᆠᨨ矄q \ Tlᆠᨨ矄q㦨llg ᨨ Tᆠᨨ矄q㦨lg

y a

\

T

q q

T矄� q

lag T ´ y 㦨lg ᨨ T㦨 a y

㡰 \

ᨨ R㦨҈맔҈ 鼀 b㡰 和盐 ᆠ �泐㦨 맔p 

犨 �ya

҈

҈

  pr T pR rg =  R  æ  r T ö  � ´҈- 㡰  ´ ҈҈ = ´ R = ç 㦨҈맔҈҈ ç  rg ÷÷  ҈ ´ ҈ è ø 

ᆠᨨ矄q㦨

T rv 

Topic-5 : Miscellaneous Problems

 ´ ҈ ´ ҈ - 㡰  = 䰘 ´ ҈ -  㦨 ҈҈ ´  ´ 䰘 ҈䰘

T T ´ A  Þ R㦨  R rv

R

㡰 ␔     ᨨ�矄ᨨ盐ᨨ ᆠ  ᨨ鼀   ᨨ ␔�� 㦨�ᆠ ᨨᆠ 盐ᨨ矄盐 ᆠ 矄�ᨨ  mg㦨FV㡰 \

rAv㦨

 �盐矄犨 �ᆠ 盐矄矄 ᨨ鼀 � � 㦨

rù é êQ ᆠᨨ矄 q = R ú ë û ҈�

盐犨�矄 ᨨ鼀 � �犨    ᨨᆠ 盐ᨨ� 㦨 rAV  �    盐 ⼄盐矄   矄盐 ᆠ  矄�ᨨ  ᨨᆠ T⏌R � 矄�    盐

҈ dr = ᆠᨨ 矄  r dt pR  d é m ù 㦨ᆠᨨ 矄  m dt ê   ú ê pR ú ë û

෌� 

d - R 㡰 㦨ᆠᨨ 矄  dt dR dR µR R  -  R - 㡰 㦨ᆠᨨ 矄  \ dt dt R

b㡰 ␔├ ᨨ犨  ᆠ矄矄矄矄盐� 矄ᨨ盐�矄� 矄泐 ᨨᨨ�ᨨ ᨨ�矄  �盐矄 �.e. P 㦨

T

T矄� q w㦨lg



␔   盐�矄 ᨨ 盐矄� � ᨨ盐�Ἐ矄 ᨨ鼀

҈ ҈ P + P + rv҈ + rgH = rv + P   ҈   Þ P졔rgH㦨 r v - v҈ 㡰 

T r

 矄ᨨ 盐    ҈ 矄 矄鼀 �盐矄矄ᆠᨨ鼀 ᨨ  矄ᨨ 盐     �� 㡰

 ᨨ ᆠ矄矄矄矄盐҈  ҈ �矄鼀ᨨ  ᆠ � ᨨ犨矄 ᨨ鼀   ҈ ᨨ        ᨨ盐鼀 ᨨ  矄ᨨ 盐 ҈ ᆠ矄矄 ᆠ㡰 ᔼ ᨨᆠᆠ矄ᨨ 犨ᨨ犨 矄�� 犨  矄矄ᆠᨨ � � � 犨�矄�� ᆠᨨ 矄 ᆠᆠ�ᨨ aᨨ犨 矄 �� 꾀矄

ᆠ�ᨨ    犨  矄  ᨨᆠ ᨨ    犨 ᨨ  矄矄 ᨨ犨 矄 �� 꾀矄  ᆠ�ᨨ    犨 盐矄 矄   犨 ᨨ犨 矄   꾀ᆠᆠᨨ � �ᨨ犨ᨨ Ἐ矄 犨ᨨ 鼀ᨨ�ᨨ  矄ᨨᨨ 犨�矄 矄矄 ᨨ犨 �  ��盐

ᨨ鼀⼄盐�ᨨ ᨨ ᆠᨨ � 盐�泐A҈v҈㦨 Av v҈㦨

A v A҈

P

᲼ v㦨v桌

 ҈ éê  æ A ö ùú v v r \ P졔rgH㦨  ç ÷  ê è A҈ ø úû ë  ҈  é æ A ö ù ê v ҈ r ç ÷ ú P졔rgH㦨   ê è A҈ ø ú ë û

P졔rgH㦨DP 꾀ᆠᆠᨨ � � ᨨ ᨨ�矄矄盐�Ἐ矄 ⼄盐�ᨨ

p DP 㡰a p DP㡰a  Q = Þh㦨 Ql hl



é æ A öù ҈ p P + rgH 㡰 a  p = ´ rv ê҈ - ç  ÷ ú ´ a  Ql Ql  ê è A҈ ø ú ë û p ҈  é d  ù  é A d  ù h= ´ rv ê҈ -  ú ´ a êQ = ú  Ql  ëê D ûú ëê A҈ D ûú

\h㦨

黨

a

ma

矄盐 



mg

P�矄�ᆠᨨ 犨

矄盐 ᆠᨨ 犨矄 ᨨ盐 矄�矄 黨 ᨨF矄盐  㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  ��ᨨ  ᨨ     矄�泐ᨨ  � 犨� ��   ᨨ鼀 �ᨨ盐 

r 㡰 = r-



꾀 㦨҈鼀鼀矄矄鼀㦨├� \ 鼀�㦨�r ҈㡰 Þ 맔�㦨r҈� 꾀 㦨҈�鼀鼀矄矄鼀㦨 㡰├� \ 鼀�㦨�r ҈�㡰 Þ  㡰�㦨r�

r�

鼀�

WWW.JEEBOOKS.IN

PS-105

Mechanical Properties of Fluids

 ö -  ⏌   -  r æ Þ ç҈ = = ÷= r҈  è  ø - ҈ ⏌   � � ´  Þ ҈=҈ \ = =    �

҈ -  

-

=

� 

\

v'

㦨

V'd'mg

Vdmg

ᔼ 矄ᆠᨨ ᆠ矄犨  鼀盐�矄� ᆠ矄 泐DT v'd'Hgg = V'd'm g

黨

dἘ vἘ = m 㦨 ᆠ�ᨨ  ᨨ  ᨨ盐鼀 ᨨ  鼀 矄盐鼀�  �

Þ V Ἐ d ἘHg 鼀ᆠ盐泐㦨 x' 矄泐㡰 \

x Ἐ d Ἐm ´ d Hg d Ἐm ´ d Ἐ Hg ҈ + g  DT 㡰 ҈ + g  DT 㡰 = = = x d Ἐ Hg ´ dm d Ἐ Hg ´ d Ἐm ҈ + g҈DT 㡰 ҈ + g҈DT 㡰 DT㡰҈

㦨 ҈졔gDT㡰 ҈졔g҈ 㦨 ҈졔gDT㡰 ҈g҈DT㡰 㦨 ҈졔 g g҈㡰DT g҈g DT㡰

xἘ - ҈ = ( g  - g҈ ) DT Þ x

㡰 和� ᆠ  矄�泐ᨨ   d㡰  矄�泐ᨨ  �⼄盐�  dL㡰 盐 盐矄> 犨��  \   矄 犨�   �ᨨ  � 矄�  �⼄盐�  \

 �ᨨ  㦨

ᨨ

a㦨

Vd L g - Vdg Vd

ᨨ

t㦨

v gt҈ = a a

t㦨

gt҈ dt҈ =  d L - d 㡰 æd -d ö ç L ÷g d è ø

v = gh

ᨨ

t㦨t҈졔

ᨨ

㦨

d d 㦨 h h 1 2

 ��㡰

 ´ dt҈  d L - d 㡰

é

ᨨ t㦨t҈ ê҈ +

ë

ù d ú d L - d 㡰 û

t҈dL dL - d

æd -d ö 㡰 和� ᆠ    �ᨨ  㦨 ç L ÷ g  �矄 ᨨ ᨨᨨ㜠�ᨨ  è

d

ø

ᨨ �矄ᆠ鼀   鼀ᨨ�ᨨ  ᨨ  �矄 ᨨ 矄�鼀 鼀ᨨ �ᆠ ᆠ㡰 ᔼ d㦨 dL      �ᨨ  =  �ᨨ  㦨和� ᆠ  矄�├矄 犨矄盐 ᆠ犨� 矄ᨨ鼀ᨨᆠ�泐�犨�ᆠᨨ � 盐 犨�  矄鼀ᨨᆠ�泐v㦨gt҈⏌ �  ᨨ犨 犨  �ᆠ�ᨨ 

dx

x A

 �㡰

\ �鼀ᨨ �矄ᨨ�⼄盐� 矄盐 ᆠ㦨t 㡰 Q t㦨 �鼀├ 泐 ᨨᆠᨨ鼀ᆠ├ᨨ ᨨ矄��ᨨ

ᨨ鼀犨 �ᆠ �犨矄矄  ᨨ t㦨t҈졔t矄盐矄�盐t ᨨ鼀 ��㡰

ᔼ   ᆠ矄矄 d =  h҈h = ҈ 鼀 ᔼ geff㦨   ᨨ犨├矄ᨨ盐矄 犨� ᨨ矄矄盐 �  ᆠ d w  盐矄 ᆠᨨ 矄�   矄鼀鼀  鼀矄矄 dm   �矄 ᆠ x ᨨ鼀 A 矄 矄 ᨨ犨 �   ��盐ᔴ � ᨨᆠ ⼄盐�  ᨨ 鼀矄矄dmᨨᨨ㦨 H dm㡰xw \ ᨨ ᆠ � ᨨᆠ ⼄盐�  ᨨ 鼀矄矄ᨨ  � Lᨨ ᨨ

æ dL - d ö ÷g è d ø

ᨨ a㦨 ç

᲼Q ᨨᆠ�泐ᨨ   盐矄  ᨨ� ᆠᨨ� 矄 犨� �⼄盐� V㦨gt҈⏌桌

h҈ g

㦨  h҈h geff> g geff㦨g geffg

盐 盐矄 - 犨��  鼀矄矄

 ᆠᨨ鼀ᨨ矄 � 矄� �⼄盐� � �鼀 t \

ᆠ㡰 ᨨ� ᨨ  �矄 ᆠ d㦨v맔t





xἘ- x = ( g  - g҈ ) DT x

u æ dv ö ÷ ᨨ 㦨h꾀 h dx è ø u æ dv ö 犨  㦨ᨨᆠ�泐� �  ç ÷ h è dx ø ҈ µh錐 µ꾀錐 µm   µ h

 gh ´

( )

pd  ´ H ´ r´ g 

ᆠ 㡰 㦨h꾀 ç

㦨

ö pd  ´ dx÷ ´ xw   ø

w  L pd  pd  w  ´ L \ ´ H ´r´ g = r´ ´ ᨨH㦨 g   

T +D T

T

ò  çè r ´

�矄 ᆠ � ᨨᆠ �矄 ᨨ�   泐   犨��  ᨨ  �⼄盐�  ᨨ �� H ␔�� ᨨ �⼄盐� ᨨ  �� H

V' v



ᨨᆠ � ᨨᆠ 㦨

pd  ´ dx 

L pd  ´ w  ò x dx    L pd ´ w ´ 㦨 r ´  

v'd'Hgg

V

ò

dm㡰 xw  犨 dm㦨 r ´

㦨 r ´

d v = m = x 矄泐㡰 V d Hg vdHgg

䰘

㦨

ᆠᨨ ��ᨨ  ᨨ ᨨ�ᨨ vdHgg㦨Vdmg ᆠ�ᨨ ᨨ ᨨ盐鼀ᨨ 鼀矄盐鼀� � 鼀ᆠ盐泐 㦨



L

L

dm

B

WWW.JEEBOOKS.IN

EBD_8341 PS-106

Physics

Thermal Properties of Matter

10

Topic-1 : Thermometer & Thermal Expansion ҈

㡰 Ӹᨨ盐 �矄鼀ᨨ 盐盐矄Ӹ㦨



Dl Dl Þ = aD \Ӹ = 꾀 ( aD ) lD

l ᆠ㡰 꾀矄犨├ ᨨ犨盐├鼀ᨨ 盐盐矄

㡰  L'҈    L'      � 矄 ᨨ   犨� 犨 

鼀盐�矄 ᆠ  �  泐 DT °ᔴ  꾀T ᔴ

Leq = L҈ + L

⏌ 꾀 矄矄矄 㦨 꾀 Dl ⏌ l) ( 矄�

矄� � ᆠᨨ �ᆠ�  ᨨ  �    矄�ᨨ 

�

a=

꾀 T + D°ᔴ L' = L' + L' eq

҈



\  Leq ҈ + a ⼄ DT 㡰 = L҈ ҈ + a҈DT 㡰 + L ҈ + a  DT 㡰 Þ L҈ + L 㡰 ҈ + a ⼄ DT 㡰 = L҈ + L + L҈a҈DT + La  DT

a҈ L҈ + a  L L҈ + L 㡰 ᔴ  � �   �  ᨨ    鼀 犨� Dl㡰 犨   �矄 鼀盐�矄 ᆠ  �  泐DT �矄 ��  泐 Dl = l aDT  a㦨ᔴᨨ �ᆠ� ᨨ �   矄�ᨨ

Dl㦨奠DT㦨҈ºᔴ  Dl -� \a = =  Þ a =  ´ ҈ l DT ҈ ´ ҈ ᨨ盐鼀ᆠᨨ �ᆠ�  ᨨ   矄�ᨨ  g = a =  ´ ҈-�

䰘

M Qr = V DV -� - ´ ҈ 㦨gDT =  ´ ҈ ´ ҈ ´ ҈㡰 =  ´ ҈ V ᨨ盐鼀 � ᆠ矄 泐奠   ᨨ  矄�泐 ᆠ矄 泐 奠 ᨨ 盐矄㡰D鼀㦨Dᨨ  A㦨pr㦨p ҈㡰㦨p맔҈ FL L aDT㦨 AY F ´  ᨨ 맔҈�맔㦨 p ´ ҈ - 㡰 ´ ҈҈҈ f \ F㦨pN\ m = 㦨p㦨├� g 㡰 ᔴ  ��  � � ᨨ ᨨ 矄矄鼀� Dl҈ = D l 



Þ a ⼄ =





la҈D q҈ = la  Dq  a҈ Dq = a  Dq҈  q   =  ҈   q㦨 ᔴ

é a҈  ù êQ = ú ë a  û

Þ

DV P = V K g= 3a

V㦨V ҈졔gDt㡰

[Q L Ἐ = L ҈ + a DT 㡰]



DP æ -DV ö çè ÷ V ø

K=

DV P P P = gDt \ = gDt Þ Dt = = V K gK aK ᆠ㡰盐ᨨ 鼀 ᆠ  ��  �  Dl㡰㦨laD  �㡰 ᨨ鼀矄矄矄 Ӹᨨ盐 �矄鼀ᨨ 盐盐矄 Ӹ㡰 = ᨨ ��盐 � 矄�

꾀 Dl Ӹ= Þ = Dl l l 꾀Ӹ

D =

l 꾀Ӹ

ᨨ鼀⼄  �㡰

҈ ᔴ

l = l a D

꾀Ӹ

㦨꾀Ӹa D

㡰 꾀 矄 泐 矄    ᨨ犨  �矄 矄鼀  ᨨ鼀 P ᨨ Q   ᨨ鼀QᨨS

㝐 ⧤







⧤ 

和

 ᔴ

 ⧤꾀 (  - ) ⧤꾀 ( - ҈ ) = Þ 㦨҈ ᔴ l l

 鼀盐 � �  \

҈ - ҈ = \ 㦨҈ ҈

 ᨨᆠ  �鼀盐ᆠᨨ矄矄㜠矄ᆠ�ᨨ 㝐 �矄  �  ᨨ鼀�矄 D 㦨҈ 쟼  矄�ᨨ � 矄鼀鼀  � � �矄 l㦨 a D 㦨 a (҈ ) ҈

\ ò dl = ҈a ò 

҈ \Dl㦨҈맔҈맔҈�맔 㦨䰘맔҈�鼀 

WWW.JEEBOOKS.IN

PS-107

Thermal Properties of Matter 黨

 � �ᨨ  泐矄ᆠ    -   㦨 ᆠᨨ 矄   ᨨ  矄ᆠ矄

ᆠ㡰

҈

Þ

mg ⏌ A mg l = Dl ⏌ l ADl 꾀矄ᨨ Dl = l a DT ᨨ鼀 �㡰  ��㡰

҈҈

l  + l҈ a a + a s l҈ as = = Þ as l҈ l҈ + l  a a + a s 㡰 ᨨ⼄盐��b�盐鼀犨h 鼀盐°ᔴ �� 㡰  盐矄 㦨 ␔ ᨨ ᨨ 泐 \ K҈Vdg㦨 Vd҈g Þ K҈㦨

d҈ d

 �㡰 K҈Vdg



KVd ' 'g d'҈

V

Vd g

d

V'



҈

㡰

㡰

ᨨ⼄盐��b�盐鼀犨h 鼀盐� ᆠ矄矄ᨨ° �� b㡰 ␔     鼀盐 �矄 � ᆠ矄     矄�泐 犨� ᆠ矄 \ d҈Ἐ㦨d҈ ҈졔gFe맔㡰  dἘ㦨d ҈졔gHg맔㡰 꾀��  盐 盐矄 㦨 ␔ ᨨ ᨨ 泐 \ KVἘdἘg 㦨 VἘd҈Ἐg \

҈

é ù d d҈ ú= K ê êë҈ + g Hg ´  úû ҈ + g Fe ´ 

é ҈ + g Fe ´  ù ú= \ K ê êë҈ + g Hg ´  úû ᆠ㡰 W҈㦨mgVda g

W㦨mg V'd'a g㦨mgV ҈졔�gb㡰

é ҈ + � g b ù 㦨mgV dag ê ú ë҈ + � g a û ෌� gbga \ ҈

҈졔�gb҈졔�gaᨨ

\ m =

da g ҈ + � g a 㡰

҈ + � g b W҈ᨨW҈W 㡰 꾀矄 ᆠᨨ 矄  ᨨ盐鼀 �矄  鼀ᨨ鼀 犨ᨨ├矄 ᨨ

ᔴ Ἐ矄犨

 ��㡰

YA a DT ҈҈҈ ´ p ҈- 㡰 ´ ҈-� ´҈ = =p» g ҈

㡰 ᨨ盐鼀ᆠᆠ�泐ᨨ ├V㦨�ᆠᆠ

Vb = V + V g ├ DT ␔  ├�矄�泐 � 犨� Vmᨨ盐鼀ᨨ 鼀ᆠ盐泐

Vb҈ = Vm + Vm g m DT  � ᨨ盐鼀 V - Vm 㡰 = Vb - Vm҈ 㡰

Þ V g ├ = Vm g M ᨨ Vm =

\Vm =

V g ├ gM

� ´  ´ ҈-

=  ᆠᆠ ҈� ´ ҈- ᨨ盐鼀V㦨Ibh

DV Dl Db Dh = + + V l b h g 㦨 ᆠᨨ �ᆠ�  ᨨ ᨨ盐鼀   矄�ᨨ 㡰 Þg㦨�맔҈�졔�맔҈졔�맔҈ 㦨맔҈⏌ C \ 盐ᨨ C㦨 ҈䰘 b 㡰L ᨨ���  � ᨨ  矄� ᔴᨨ㜠 �ᆠ�  ᨨ  �    矄�ᨨ  ᨨ  矄矄 �矄 �  

 ᨨ ᆠᨨ� a B > a C   矄矄 \ g=

LB㦨L ҈졔aBDT㡰 R졔d 㡰q 㦨L ҈졔aBDT 㡰 꾀�� LC㦨L ҈졔aCDT 㡰㦨Rq

\

҈ + g Fe ´  K d҈ Þ ҈ = K  ҈ + g Hg ´  d

 �㡰

mg l mg = Al a DT A a DT

҈ 㡰

V'd' g

d'

҈

Y=

҈�

Þ

F Dl ⏌ A l

\ Y =

 - 䰘 °Ӹ - -҈㡰 䰘 泐 + ҈ = Þ = 䰘 - 䰘 -� - -҈㡰 ҈ ҈҈ \ Ӹ㦨 Ӹ ҈ ᆠ㡰 ␔     � 矄 ᨨ ᆠ ᨨ  � ᆠ矄矄 泐  矄鼀 鼀ᨨ盐  \ Dl a = Dl s Þ l҈a a t = l  a s t a l  aa l Þ  +҈ = a +҈ = l҈ as l҈ a s

㡰 ␔├ ᨨ犨   Y =

ᨨ

(R + d )q Rq

ᔴᨨ



҈ + a B DT = ҈ + aC DT

q

R+d = (҈ + a B DT ) (҈ - a C DT )  R ᲼泐� ᨨ鼀�   矄�ᨨ 桌

d = ҈ + ( a B - aC ) DT - a B aC DT 㡰  R d d = ( a B - a C ) DT ᨨ R = ᨨ R ( a B - a C ) DT ҈ ҈   R µ  \ Rµ a B - aC DT ҈ ᔼ ��泐  鼀盐 T  ᨨ泐  ᨨᆠ FB㦨鼀�ᨨ Axrl g = ALrb g ᨨ

҈+

\ xr l = Lrb

 �㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-108

Physics 꾀



F'B

r

o

 rl

Þ

ᨨ A Ἐ xr Ἐl g = ALrb g

r Ἐl = rl ҈ - gDT 㡰

Þ

\

A ҈졔a DT㡰x rl ҈ - gDT 㡰 g 㦨ALrbg

Þ

xrl ҈ + a DT 㡰 ҈ - gDT 㡰 = Lrb

Þ

xrl ҈ + a DT 㡰 ҈ - gDT 㡰 = xrl



᲼ ᨨ鼀⼄ �㡰桌

҈



�ᔴ

Þ K҈ 㡰 = K  �㡰 = K 㡰







黨�ᔴ 矄



h҈㦨�ᆠ鼀h㦨�҈ᆠ鼀h㦨黨ᆠ鼀 矄矄盐 B㦨 矄矄盐C P㦨d黨� ᔴgh҈d� ᔴgh㦨P졔d� ᔴghd黨� ᔴgh

ᨨ

K҈ K  K Þ K҈  K   K = ҈   ҈� = = ҈  ҈� Þ K҈  K =    㡰 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  ᨨ   ᨨ �矄 ├� �ᆠ  �泐 �矄 ᆠᨨ   � ᨨ  �    犨ᨨᨨ  Þ





҈ - 䰘㡰 K҈ A 䰘 - 㡰 K  A  - 㡰 K A = = l l l

Þ K҈ ҈ - 䰘㡰 = K  䰘 - 㡰 = K  - 㡰





㡰 꾀矄 ᨨ 矄�  �ᆠ矄ᨨ 泐 矄鼀 �  l㡰  ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ  A㡰 泐ᆠᨨ

ᆠ � 矄�矄 和ᨨ ᆠ盐 犨�矄鼀 ᨨᨨ 矄

Þ





b W - W҈ 㡰 W - W҈ + W - W 㡰 t - t҈ 㡰 W - W 㡰

æ DQ ö æ DQ ö æ DQ ö  ᆠ盐  = ç ÷ =ç ÷ =ç ÷ t t D D è ø AB è ø BC è Dt øCD



҈

gl =

Topic-2 : Calorimetry and Heat Transfer

Þ ҈졔a DTg DT㦨҈ Þ g㦨a ᨨg�㦨µ矄  矄�泐ᨨ �⼄盐�  ᆠ矄矄矄鼀盐�矄矄ᆠᆠᨨ � � ᨨᨨ� d㦨dt ҈졔gt㡰犨 g㦨ᆠᨨ㜠 �ᆠ� ᨨ ᆠ盐�ᆠ   矄�ᨨ  ᨨ �⼄盐� 

ᨨ

W - W҈ ҈ + g l DT W - W҈ ҈ + g l t - t҈ 㡰 Þ   = = W - W ҈ + bDT W - W ҈ + b t - t҈ 㡰

Þ WW҈㡰᲼҈졔b tt҈㡰㦨 WW㡰᲼҈ + g l t - t҈ 㡰桌

ᨨ犨AἘ㦨A ҈졔aDT㡰

矄

V ҈ + b DT 㡰 ´ d l ´ g  㡰 ҈ + g l DT

W - W҈ Vd l g ҈ + g l D T 㡰 = W - W V ҈ + bDT 㡰 d l g

\ FB Ἐ = mg

�ᔴ ᨨ 黨�ᔴ

 �㡰

�� � � �㡰泐 㡰犨�

꾀 鼀盐 T 졔 DT   ᨨ盐鼀 ᨨ    ᆠ盐 � ᆠ矄矄 盐    矄�泐 ᨨ  �⼄盐�  ᆠ矄矄 矄ᨨ   盐ᨨ 犨 �ᆠ  ᆠ盐�矄�鼀鼀矄 �  �⼄盐� 鼀� 矄矄鼀

҈黨

 dl = dl Ἐ ҈ + g l DT 㡰

WW㦨

mg

鼀�

 ���㡰

ᨨ鼀⼄ ��㡰 ���㡰  �㡰

x

x

꾀矄ᨨV Ἐ㦨V ҈졔b DT㡰

҈  ҈ mv ´ = ms DT  

d黨� ᔴ h҈졔h㡰㦨d� ᔴ h졔h㡰

d黨�°C h + h d  ⏌ (҈ + 黨�g ) h + h = = ᨨ d �°C h҈ + h d  ⏌ (҈ + �) h҈ + h

҈ + �g �҈ + 黨 ҈ ҈ = = = ҈ + 黨�g � + 黨 ҈҈ ҈҈ ᨨ ҈졔黨�g㦨҈҈졔�맔҈҈g ҈ ´  ´ ҈  ᨨ 黨�g  �黨g = ҈ ᨨ g = 黨黨҈ g  ´ ҈  \ ᔴᨨ �ᆠ� ᨨ �   矄�ᨨ a㦨 =   \ a㦨䰘맔҈� ᔴ   gl    ᆠᨨ �ᆠ�  ᨨ  ᨨ盐鼀   矄�ᨨ  ᨨ  ᆠ盐 犨��    犨��  㦨 盐  盐矄



ᨨ

WW҈㦨  ´ l ´ �

 �㡰

WW㦨  Ἐ´ Ἐl ´ �

 ��㡰

v ҈ ´ ҈ = = 䰘�°ᔴ  ´ s  ´  ´  ´ ҈ 㡰 �ᆠ鼀矄 盐ᨨ犨  鼀ᨨ盐 ᨨ �ᆠ鼀矄㦨m�ᆠ

Þ DT =

mw sw Dq = m�ᆠ L�ᆠ  = 

\ m�ᆠ =

 ´  ´ �

 ´ ҈�

mw sw Dq L�ᆠ

= ҈䰘 ├�㦨҈䰘�

㡰  ��  泐犨 = mw Cw T鼀� - Tw 㡰  =  ´҈´ ҈ - �㡰 ├ 泐矄鼀㦨mL矄鼀졔m Cw Ts  T鼀� 㡰 㦨鼀맔�졔鼀 ҈㡰맔 ҈҈㡰㦨鼀맔�졔鼀 ҈㡰맔 黨㡰 ᨨ鼀 � ᆠ�ᨨ ᆠᨨ�鼀  ᨨ矄 㦨  �� 

WWW.JEEBOOKS.IN

PS-109

Thermal Properties of Matter

\ 㡰 ҈ - �㡰 = m ´ � + m ҈㡰 黨㡰 쟼 �泐 盐 

Þ ҈ = m 黨㡰 Þ m »  �

㡰 矄� �   � ᆠ� ᨨ  ᆠᨨ�鼀泐

Þ M �㡰졔M맔҈맔 ҈㡰㦨맔졔맔҈맔 ÞM㦨ÞM㦨g 

㦨�� 鼀맔矄Dq 㦨鼀҈矄矄矄 Dq1 졔鼀矄犨졔Dq2㡰 Þ҈黨맔和맔 ҈҈�㡰㦨҈맔黨맔 ҈�㡰

㡰 M҈C�ᆠ맔 ҈㡰졔M҈L = MCw  �㡰

和ᨨ� �犨�졔맔맔 ҈�㡰

ᨨM҈맔ᔴ�ce 㦨�㡰맔҈졔M҈L = M맔҈맔�

和㦨黨҈├�҈├҈

�M  Þ = -� M҈

҈ 㡰 q d

d

䰘

㡰 H҈㦨H q



æ q - q ö æ q - q҈ ö æ q + 黨q  ö = kA ç ᨨ q = ç ҈ ᨨ k 㡰 A ç ÷ ÷ è d ø è d ø è ҈ ÷ø 㡰 쟼 ᆠ�  鼀 ᆠᨨ 盐ᆠ��泐ᨨ  矄泐矄鼀 ⧤ ⼄ = =

= 黨



k

k q҈

⧤҈꾀҈ + ⧤  꾀  꾀҈ + 꾀 

⧤҈ p  㡰 + ⧤  p  㡰 

⧤

=

⧤҈ + ⧤  

㡰 鼀�鼀ᨨ �ᆠ�矄   ᨨ鼀� ᆠ�ᨨ ᆠᨨ�鼀  ��   泐�ᆠ㡰 㦨  ᨨ矄 泐犨㡰 \맔҈맔鼀졔 鼀㡰맔㦨�맔맔 䰘鼀㦨졔 鼀㦨҈

҈

ᆠ㡰 ᨨ矄矄㦨�� 㦨鼀和Dq 和ᨨ鼀꾀和꾀Dq꾀㦨鼀和Dq Þ ҈맔和꾀맔 ҈黨㡰㦨�맔和맔 黨䰘�㡰

 和   ᨨ犨҈맔和꾀맔 ҈q㡰㦨�맔和맔 q�㡰

和꾀㦨҈�和Þ和꾀㦨

҈ 꾀

鼀ᨨ

鼀ᨨ 矄ᨨ盐ᆠ 矄ᨨ� ҈鼀 ҈҈ 㡰   ҈ ⧤ ҈ ⧤ æ 턼 ö ├꾀D

çè ÷ø 㦨  l

⏌

⏌



⏌

⏌ 턼



⏌

졠 

҈ ´ �   㦨� ᔴ 맔 㦨  �  ҈ 㡰 꾀ᆠᆠᨨ � � ᨨ � ᆠ� ᨨ ᆠᨨ�鼀泐 턼�� 㦨턼盐矄 맔和맔 ҈�㡰㦨҈�맔҈맔 䰘㡰졔�맔 䰘㡰 맔和맔҈҈㦨҈�맔҈졔�맔҈ 和ᆠ� �ᆠ ᨨ 盐鼀� �盐鼀 D 턼 =

҈ ´ � ´ 䰘 = ⏌├�㜠 ᔴ  ´ ҈҈ ҈� 㡰 꾀ᆠᆠᨨ � � ᨨ � ᆠ� ᨨ ᆠᨨ�鼀泐 ᨨ矄㦨 ��

҈맔҈ 䰘�㡰㦨҈맔҈맔�졔҈䰘맔҈맔� ҈T䰘�㦨�졔䰘�㦨҈ÞT䰘�㦨҈ T㦨� C

和=

҈

b㡰  ᆠᨨᨨ㦨 \ ᆠᨨᨨ㡰㦨

æ ö 맔 çè ÷ø 맔 ҈q㡰㦨 q�㡰  q㦨q҈ 㦨�qÞq㦨 ᔴ

⏌

ᔼ  矄 泐矄 鼀盐 �  ᆠ 犨     턼

⧤҈꾀҈

p  㡰

D 꾀 ҈ ҈ ´ � = =  꾀  �



꾀

⧤҈p  + ⧤  ᲼p  㡰 - p  桌

p

( ҈)( 黨)

= 黨 ␔⏌鼀  ҈ ҈ ᆠ㡰 矄ᆠ� �ᆠ ᨨ 盐 ├ ᨨ犨 鼀 �矄꾀ᆠᆠᨨ � � ᨨ � ᆠ�ᨨ ᆠᨨ�鼀泐  ᨨ矄



M�ᆠLf졔m�ᆠ 㡰Cw㦨m矄鼀Lv졔 m矄鼀 ҈㡰Cw

҈ æ 턼 ö ├D

çè ÷ø 㦨 꾀  l

҈䰘

mc D T V rc DT = t t

҈ ´ ҈ ´  ´҈ ´   ´  ´ 

\ᆠᨨᨨ㦨䰘␔ b㡰 꾀矄 Pt 㦨 mCDT 和ᨨ P맔 ҈맔 㦨 mC ҈  �㡰  P 맔 ��맔  㦨 鼀  ��㡰 �� � � ⼄盐�ᨨ  �㡰 泐 ��㡰 犨 �

҈ C ´҈ = �� L \ L 㦨 �� ᆠ⏌�

WWW.JEEBOOKS.IN

EBD_8341 PS-110

҈

Physics

ᆠ㡰 ᨨ   ᨨ犨 �矄�� 泐

҈

p  D r = p ᲼  - - D 㡰  桌

⧤꾀 q҈ - q  㡰 l ␔  ⧤ 㦨 ᆠᨨ �ᆠ�  ᨨ   鼀 ᆠᨨ 盐ᆠ��泐 l㦨  �  ᨨ ᨨ   꾀 㦨  ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ  ᨨ ᨨ

턼㦨

҈ ᔴ

和

Þ r  D  = ᲼  -  +  D - D  桌

Þ r  D  =  D

T rL  㡰 꾀矄   矄盐ᨨ盐 � � �矄 �  �ᆠ 矄矄 �矄 �  �ᆠ �鼀├ ᨨᆠᨨᨨᨨ 犨 �⼄盐�  ᨨ鼀 ᔴᨨ� ᔴ㡰 �矄 矄鼀鼀� 盐矄  ᨨ

矄矄  ᔴ

 ᔴ

æ 턼 ö æ 턼 ö =ç ÷ çè ÷ø  犨 è  ø �⼄盐�

ᔼ  盐 ᆠ�ᨨ  鼀盐�矄   

턼ᔴᨨ㦨턼矄矄졔턼和

鼀犨 ᔴ 犨 + ␔㡰D 鼀l ᔴl + ␔㡰 D

=   ␔ 㦨 犨  ⼄盐�  ᨨ    矄矄㡰 ᨨ 鼀 犨 ᔴ 犨 = 鼀 l ᔴ l

黨 ´  ҈ - T 㡰 

ᨨ

 ´  ´ T - 㡰 ҈ ´  ´ T - 㡰 졔 ҈ ҈ Þ  㦨 졔 Þ 㦨 ᔴ

㦨

҈黨

\和ᆠ� �ᆠ ᨨ �⼄盐� ᔴl㦨

黨 ´  ´  =  ᆠ⏌矄  ᆠ㡰 ᔼ    ��  ᨨ鼀  �  鼀盐 ᨨ  矄  \

Qᔴᨨ =

= (   -   ) = 

鼀盐 ᨨ  矄盐ᨨ盐 � � 矄盐 㦨   ᔼ ��鼀盐ᨨ 矄  � ��㦨   和ᆠ� �ᆠ  ᨨ  鼀� ᨨ   矄  �矄 矄

ᆠ = a  盐 �鼀矄矄 a㦨ᆠᨨ 矄 㡰 꾀泐� � ᨨ鼀盐

(

s꾀   =

- 矄盐  㝐ᆠ

)

s p  é   Þ  =   ) - (  ) ùú (  ê ë û  㝐a (  )   Þ  =

㝐a 䰘   s  p  ´  

和ᨨ� � 犨 �

�鼀├  ᨨ  矄 ᨨᆠᨨᨨ ᨨ犨  鼀盐  

㝐a

æ ҈ ö  ç ÷ ҈p s è  ø  㡰  T    �  矄 泐 矄 鼀盐 ᨨ    ᆠ├ ᨨ 泐 ᔼ  矄 泐 矄 쟼 �泐ᨨ矄 㦨 쟼 �泐��  s T  T㡰맔pR㦨I pR㡰 =

᲼D �矄泐矄鼀桌

ÞR=

ᔴᨨ 

㡰 ␔    �盐矄 �矄 ᆠ矄 泐D 



 \ �䰘 ´ ҈ - éêT  - (  ) ùú ´  = 黨҈ ë û \ T㦨⧤

㦨 

鼀␔ᔴ␔ 鼀l

� ´ ҈ = � ├ᆠ ⏌ ├� ҈

㡰 쟼⼄盐�   鼀 矄�矄 ᆠ �  ᆠᨨ ��盐�ᨨ 㜠ᔼ

L L  L + = KA KA  KA 쟼⼄盐�   鼀 矄�矄 ᆠ �  ᆠᨨ ��盐�ᨨ 㜠ᔼᔼ R = R҈ + R =

R l KA  KA ᨨ ҈ ҈ ҈ RP = = s = + = +  � KA RP R҈ R l l � 鼀矄�矄 ᆠ� ᆠᨨ ��盐�ᨨ ᔼᔼRP�矄��鼀矄 矄矄     鼀 矄�矄 ᆠ�  ᆠᨨ ��盐�ᨨ   ᔼ Rs ts 黨 = s = s � �  ᆠ㡰 꾀矄 矄 ᨨ犨  �   ��盐    ҈⏌矄  ��  泐 犨 ᨨ�矄 �矄 鼀盐 㦨 ҈҈㡰㦨⏌矄 l ᨨ犨    ⼄盐�  ᨨ�矄  鼀盐ᨨ 犨 ᨨ鼀䰘 ᔴᨨ䰘䰘 ᔴ Q㦨mcDt㦨맔맔�  ᆠ�鼀⼄盐� ᨨ�� 턼 ҈⏌矄 鼀ᨨ盐  ᨨ   \

�t P = t s Þ t P =

 ´  ´ � Q = 㦨�矄㦨鼀� 矄   � 㡰 ҈ ᔴᨨ� �矄   鼀ᨨ盐  ᨨ   ⼄盐� ᨨ �矄 鼀盐ᨨ ҈�鼀ᨨ 犨 ᨨ鼀҈� ᔴᨨ҈�� ᔴ䰘 鼀鼀ᨨ �  㡰 ␔鼀� �ᨨ �矄矄ᨨ 盐 盐ᨨ �鼀 �矄�鼀�泐 盐 ᨨ  ��ᨨ 꾀 鼀 �盐鼀 �矄 ⼄盐�  ᨨ ᆠᨨ ᆠ�ᨨ

ᨨᆠ矄矄 꾀矄  盐 �矄 鼀ᨨ矄 ᆠ盐   ᨨ鼀   �鼀  �矄  矄鼀�   ᨨ盐�   ��ᨨ  t㦨

WWW.JEEBOOKS.IN

PS-111

Thermal Properties of Matter 䰘

㡰 꾀ᆠᆠᨨ � � ᨨ ␔� Ἐ矄 �矄ᆠ鼀  犨

҈

lm맔T㦨ᆠᨨ 矄  ᨨ鼀 �  l m < l m < l m҈



 ҈

 T1 T2

T

\ T>T>T҈

鼀盐ᨨ 和盐 T�矄 ��    ᨨ 犨 � � ᆠT犨 �ᆠ � 盐 �矄 �  盐 �矄  �鼀 㜠T҈ 㡰 ᔼ  ᆠᨨ鼀� �ᨨ  ᨨ ᨨ 矄 KP㦨K҈졔K㦨K졔K㦨K





҈ ᔴ K



ᔴ

l ⧤





ᔼ  矄�矄 ᆠᨨ鼀� �ᨨ



æ -dT ö æ dT ö ᆠ㡰 ᨨ鼀 �  ç > è dt ÷ø x çè dt ÷ø y

æ -dT ö ÷ µ 鼀�矄矄��泐 㡰 dt ø

 ᨨ ᆠᨨᨨ� � ç è

KK K K - K = KS = ҈ 㦨 K  K҈ + K 

҈ ᔴ ⧤

b㡰 矄 犨  �├�ᨨ 犨 ᔴ 矄ᨨ ᔴ 鼀盐 㦨mCw DT㦨�맔҈맔㦨҈├ᆠ ⼄盐� 泐├��ᆠ ᔴᨨᆠᨨ � ᨨ├�ᨨ �ᆠ ᔴ 㦨mC�ᆠ DT㦨맔�맔㦨├ᆠ  ᆠ鼀� � �҈㦨├ᆠᨨ  犨�鼀鼀├��ᆠ  ᔴᨨ犨 ᔴ Q㦨mL Þ 㦨m맔 Þ m㦨҈├�

 ᨨ 鼀ᨨ盐  ᨨ 犨  ᔴ 㦨�├�졔҈├�㦨├� 꾀 鼀ᨨ盐 ᨨ �ᆠ ᔴ㦨҈㦨҈├�

\ Ex>Ey 꾀矄ᨨ ax > ay 矄 �ᨨᨨ  矄ᨨ矄 �ᨨᨨ  鼀�矄 ᨨ





ᔴ

l

l



 K A ҈㡰 KA ҈㡰  q = l  l ҈ q KA ҈㡰 = ´ = \ q҈ l  K A ҈㡰  ᆠ㡰 ᨨ鼀�Kᨨᨨ�� �鼀盐T� ᆠ矄矄� 泐 矄 Q 㦨 mc DT  ᆠ T  t �  犨�   矄��  �  � ᆠ�  ᨨ�鼀 �矄 盐� �ᨨ�� � Q㦨mL

鼀盐 鼀� 矄 ᆠᨨ 矄  � ᨨ�� � �矄 ᆠᨨ鼀  � 犨�矄�� � 矄ᨨ�鼀 �矄 꾀  鼀盐� ᆠ矄矄� 泐T㜠t� 犨� 矄�� � � ᆠ�  ᨨ�鼀 �矄 b㡰 ᨨ鼀犨� Ἐ矄 �矄ᆠ鼀 犨 l鼀T㦨ᔴᨨ 矄  ᆠᨨ 矄  \ T= lm q҈㦨

黨



C C C ü ì T = T = í\ TA = ý -䰘 B -䰘 C  ´ ҈  ´ ҈ � ´ ҈ -䰘 þ î

y x

҈





㡰 꾀ᆠᆠᨨ � �ᨨ⧤�ᆠ ᨨ Ἐ矄犨�ᨨᨨ 矄ᨨ矄�ᨨᨨ 鼀�矄      ᆠᨨ矄 꾀 �� 鼀盐 �   盐 ᆠ㡰矄� ᆠ�矄ᨨ矄鼀ᨨ  �泐 � 鼀�矄 鼀ᨨ  ��ᨨ 矄 矄 犨    ᆠ �矄   �� 矄   � �矄   ├矄 ᨨ 泐� ��泐



b㡰  q°ᔴ  鼀盐ᨨ 盐 ᆠ�ᨨ BQ�矄    ᨨ犨� �矄ᆠᨨ  ᨨ鼀A黨 CᨨBq C ᨨ

ᆠᆠᨨ盐  ᨨ  鼀盐 �  ᆠ \

Q㦨

KA 黨 - q 㡰 l

꾀 矄鼀 ᨨCᨨB.

 �㡰

Q=

KA 黨 - q㡰 l A

꾀��  ᨨ鼀 矄  Ἐ矄 犨 Q㦨sAT\ QA㦨s.p 맔҈㡰맔 QB

㦨s.p 맔҈㡰맔

҈ ´ ҈ -

Q D

C

ᨨᔴ

� ´ ҈ -

 QC㦨s.p 맔҈㡰맔  ᆠQB>QC>QA

C

黨ᨨᔴ



C

턼

ᨨᔴ

qᔴ ᨨ





� ´ ҈

B

C 黨ᨨᔴ

-

\

  ᨨ犨� � 矄ᆠᨨ  ᨨ鼀Bᨨ D

WWW.JEEBOOKS.IN

EBD_8341 PS-112

Physics

KA q - 㡰  ��㡰 l �� � �⼄ ��㡰泐 �㡰 q 㦨  Þ  q = ° 黨 - q  ᆠ鼀盐ᨨ  盐 ᆠ�ᨨ q㦨 ᔴ b㡰 꾀ᆠᆠᨨ � �ᨨ␔� Ἐ矄 �矄ᆠ鼀 犨lT㦨ᆠᨨ 矄  ᨨ鼀� l҈ll \ T҈>T>T 㡰 졠®꾀 鼀盐ᨨ �ᆠᆠ  �矄 ᨨ鼀҈ ᔴᨨ ᔴ 꾀®�ᆠ ᔴ鼀矄� ᨨ犨 ᔴ ®ᔴ犨 ᔴᆠ  �矄� ᨨ犨҈ ᔴ ᔴ®犨҈ ᔴᆠ  �矄� ᨨ矄鼀҈ ᔴ

黨

Q㦨

� 

҈⏌  ⏌ù æ ҈ö DT esAT  esT  é æ m ö k êp ç ú = = 㦨 çè ÷ø m Dt mc mc ê è  prø÷ úû ë

 ᨨ ᨨ   ��  犨ᨨ ᨨ �矄

ᨨ

DT҈ ⏌ Dt҈ æ m ö = DT ⏌ Dt çè m҈ ÷ø 

鼀

꾀 ᨨ ᔼᆠ

ᔴ ҈ᨨ ␔

䰘

lmT㦨맔҈nmK

U E



 ´ ҈ nmK = ҈ nm  K



U l鼀

黨黨 �㡰

黨黨黨 ҈黨黨 ҈㡰 ҈�㡰

l

T - Tc

E ⏌ t ҈㡰 㡰    = = = � �㡰 ҈㡰  ᨨ

E 㦨�맔㦨҈␔ t

A 2a

a B

a

C

TC

2T

=

K2 R

K1

2R l

E   = sT  ´ A = sT ´  pr t ᨨ  �㡰

T

Tc -  T Þ T - Tc =  Tc - T a a Tc  Þ T = Tc  + ҈㡰  Þ = T  +҈ ҈ ᆠ㡰  K 㦨  鼀 ᆠᨨ 盐ᆠ��泐ᨨ   矄泐矄鼀

ᨨ  矄  ᨨ    矄ᆠᨨ   ᨨ盐�    ᆠᨨ鼀�  矄泐矄鼀 㦨   矄   矄ᆠᨨ  ᨨ鼀 鼀� 犨�  鼀 ᆠᨨ 盐ᆠ��泐K҈ 졔   矄   矄ᆠᨨ  ᨨ鼀 鼀� 犨�   鼀ᆠᨨ 盐ᆠ��泐K

ᔼ ᨨᨨ犨矄   �泐 � 犨 黨黨nmᨨ�nm 犨�矄矄   鼀� 犨 黨黨黨nmᨨ҈nm �U҈UᨨU>U҈ 㡰 ᨨ鼀 和  Ἐ矄 犨  �泐 �   矄ᆠᨨ  泐 ᆠ├ ᨨ 泐

E = � 犨  T㦨�Kr㦨҈鼀 t \ �㦨ps �㡰 ҈㡰 E 犨  T㦨҈Kr㦨鼀 = 䁸 t E \ =  p s ҈㡰  㡰  t �� � �⼄ ��㡰泐 �㡰犨�

DQ k A DT = Dt l

æ DT ö ÷  = ç è a øCB

ᨨ    矄ᆠ盐鼀 lm㦨

҈⏌ 

æ DT ö ᨨ矄� 矄AC CB ç ÷  è a ø AC

Þ

 犨 �    ├

æ ҈ö = ç ÷ è ø

b㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  鼀盐  B = T > 鼀盐A㦨T矄ᨨ  ᨨ犨 ᨨ鼀BᨨAAᨨC C ᨨ B ᨨ 矄 泐矄ᆠᨨ ��ᨨ  D턼 D  �矄 矄鼀

矄盐�

㡰 꾀ᆠᆠᨨ � � ᨨ ␔� Ἐ矄 �矄ᆠ鼀  犨

҈⏌ 

꾀泐� �  ᆠᨨ 盐ᆠ�ᨨ  ᨨ鼀盐

 ҈ᨨ 和鼀

ᨨ ␔

졠 ᨨ ҈ ᔼᆠ

㡰 꾀ᆠᆠᨨ � � ᨨ和  Ἐ矄 犨 DQ㦨esATDt 꾀矄ᨨDQ㦨mcDT ᨨ mcDT㦨esATDt

KADT K҈ A҈DT K  A DT = + l l l    Kp R㡰 㦨K҈pR 졔 Kp᲼ R㡰R桌

K ҈ + K    㡰 ᨨ鼀� ᆠ�ᨨ ᆠᨨ�鼀泐 ᨨ

K 㦨

ᨨ矄泐矄鼀㦨��  泐 犨졔ᆠᨨ�鼀㡰 mL졔m맔c맔 ҈㡰㦨҈҈맔c맔 ҈�㡰 m᲼�졔҈맔桌㦨҈҈맔҈맔� m㦨҈├�

 ��㡰



b㡰

Q Q nCv DT ҈ = = Þ Q = ҈ g Q҈ nC p DT g

Þ

Q =

䰘 = � ᆠ ҈

WWW.JEEBOOKS.IN

PS-113

Thermal Properties of Matter



㡰 ᨨ鼀鼀矄㦨 㝐㦨



=

 鼀矄

黨

RT m

 ´ ҈ ´ 黨 ´ ҈ = � ҈黨 ´ ҈黨

b㡰   鼀⼄盐���盐鼀 q A - q B = °C ෌� 㡰 KA㦨KB ෌� 㡰

KA q + l A q ᔴ 㦨 KA + l

\



q C 㦨

qᔴ

q꾀 KB qB l  KB l

q

KA

KB

l

l

q A + q B q A + q A -   q A - ҈㡰 = =   

\ q A - qC = ҈°C  ᆠ   鼀盐 �  ᆠ ᆠᨨ矄矄   泐 A㦨҈ C 黨㡰 꾀ᆠᆠᨨ � �ᨨ矄  Ἐ矄犨 P µ T  ᨨ P = PT  \ ᨨ�  P = ᨨ�  P + ᨨ�  T  \ ᨨ� 

P = ᨨ�  T P

P =  ᨨ�  䰘 = ҈ … �㡰 꾀 㦨䰘 ᔴ㦨䰘⧤ ᨨ�  P 꾀 㦨䰘䰘 ᔴ㦨⧤ r ᨨ�e = ᨨ�   =  ᨨ�  䰘 ´ 㡰 r  =  éëᨨ�  䰘 + ᨨ�   ùû = ᨨ�  䰘 +  = ҈ +  = 黨 䰘 㡰 ᨨ鼀 �㡰 和  㜠ᨨ 鼀

 犨 P 㦨 sAT    ��㡰 ␔� Ἐ矄 �矄ᆠ鼀 犨㦨lm맔T㦨ᆠᨨ 矄 

PA AA = PB AB

L ҈� = = 䰘°C C � �҈ 㡰 ᨨ   ᨨ犨犨�矄鼀

\

ᨨ   ᨨ犨 犨  R =

A l = A´ B TB AB l A ҈ é  ´  ù  ê ú 

é R P l A é AA =ê ´ ú =ê A´ Bú =  l B ë AB PA û ë ҈ êë RB PA úû l \ A 㦨 lB 黨㡰 꾀ᆠᆠᨨ � � ᨨ矄  㜠ᨨ 鼀

犨

p ( r ) L҈ L K A =  \ ҈ =  = =  [Q L҈ = L = L ] K҈ A҈ K  A K  A҈ pr 

û

�

ᨨ ᨨ  �泐  � 泐 꾀 ᨨ ᨨ  �泐  � 泐  

æT ö æ r ö = ç ҈ ÷ ´ç ҈ ÷ 㦨   sT pr 㡰 è T ø è r ø æ l m 㦨 çç l è m҈





2

æ ҈� ö æ  ö 㦨黨 㦨 ç è � ÷ø çè ҈ ÷ø

和ᨨᨨ犨ᆠ� 泐鼀 㦨 ҈␔⏌鼀㡰 鼀㡰㦨␔ 㝐矄矄ᨨ �ᆠ㦨�㦨├� ⼄盐� ᨨ鼀�ᆠ㦨鼀 㦨 㡰 맔҈�㡰㦨黨맔҈ ᔼ t�矄 �鼀├  ᨨ �ᆠᨨ鼀 Eù é \ 㡰t㦨黨맔҈ êQ P = t ú ë û



ù ö æ r҈ ö é T҈ l m 泐 ␔� Ἐ矄犨 ú ÷ ç ÷  êQ = ÷ è r ø ê T l m úû ҈ ë ø 

L KA



҈ ù

҈ PB ù 

sT҈ pr҈ 㡰

dQ 鼀 �  ᆠ ҈ = = ( T  T҈ )  鼀矄�矄 ᆠ R dt

    ҈ = ᨨR҈㦨R R҈ R

TA

\



҈ ҈ ´  ´ ҈� ´�+ ҈ ҈  \鼀= = � Þ  = 鼀 ´ ҈� +  ҈� � 䰘°ᔴ㡰C 矄ᆠ� �ᆠ ᆠᆠ�泐ᨨ �⼄盐�         ᨨ ᨨ盐�矄�ᨨ  ᨨ鼀� ᆠ�ᨨ ᆠᨨ�鼀泐 ᨨ矄㦨 ��

mCSCD 㦨mCDT졔mL ᨨmCSC ҈҈㡰㦨�ᔴ 㡰졔�  �㡰 ␔ mC㦨鼀矄矄ᨨ ᆠᨨ�鼀 SC㦨矄 ᨨ ᆠᨨ�鼀 꾀��  犨   � �⼄盐�  �矄 ᨨ盐    ⼄盐���盐鼀 鼀盐�矄� ᔴ mCSC �㡰㦨ᔴ �㡰  ��㡰 ᨨ鼀⼄ �㡰 ��㡰 ҈ᔴ㦨�ᔴ졔� Þ  = 鼀 ´

 ᆠ  �矄 �矄  �

㡰 꾀矄 �矄 ᨨᨨ   ᆠ  ��  �矄ᨨᆠ矄矄和ᨨ  矄盐�  㦨  盐矄  �  ᆠᨨ � � 鼀 �鼀矄 ᨨ  �ᆠ ᨨ鼀� ᔴᨨ ᔴ졔盐矄 � ᆠᨨ � �҈�鼀ᨨ �ᆠ  ᔴᨨ犨 ᔴ ᨨ㦨mcD q졔ml

ᨨ �

t㦨

黨 ´ ҈ 矄 = 矄 º ��鼀�



 t    鼀盐 ᨨ   �  ᆠ     矄 泐 矄 �矄 ᆠ  

   矄    矄ᆠᨨ   ᨨ盐�  A Q҈㦨K҈A ҈t㡰

   矄    矄ᆠᨨ   ᨨ盐�  B Q㦨KA t㡰 꾀矄 泐矄K҈A ҈t㡰㦨KA t㡰 Þ  ҈t㡰㦨 t㡰 Þ t㦨t Þ t㦨 ᔴ

WWW.JEEBOOKS.IN

EBD_8341 PS-114

Physics

�

ᔼ ├矄 t 矄ᆠᨨ 矄 ᨨ   矄盐矄 ᆠ ᨨ 矄ᨨ� � 泐 �� 㡰

 ᨨᨨ 矄 � t矄ᆠᨨ 矄㦨P맔t 㦨mL 盐矄�ᨨ

P ´t \ L 盐矄�ᨨ 㦨 m

��

ᨨ    矄  ᨨ

P=

P=

鼀盐 �   鼀 矄�矄 ᆠ



t ⏌  pR K

t=





pKTR  P 쟼 �泐 �   矄ᆠᨨ dT sTA㦨mc dt Þ

 r ´ p r cdT  dt 㦨  = sT A s T  ´  pr  mcdT

҈



ᨨ  ᆠ  �



l -t 㡰 ù é êQ 鼀 矄�矄 ᆠ㦨 KA ú ë û

T

pKTR  P �.e.  �ᆠ├ 矄矄 t 矄 ᨨ盐 Þ

�黨



졠 ® 꾀 鼀� �矄 �  矄ᨨ�  矄 ᨨ 泐 鼀盐 �矄 � ᆠ矄� � ᨨ鼀꾀® 鼀��矄泐矄ᨨ�  泐 �⼄盐�  和� ᆠP�矄ᨨ� 犨 A B  ᨨ 鼀� �矄 泐矄ᨨ�   泐�⼄盐�  矄㡰 쟼 �泐 �   矄ᆠᨨ  泐  �矄 矄  E҈㦨esT A㦨es 㡰맔p맔҈҈맔҈҈ 㦨҈맔p맔҈҈맔es 쟼 �泐  �   矄ᆠᨨ  泐   矄ᆠᨨ  矄  E㦨es맔 㡰맔p맔맔 㦨҈p맔҈҈맔es \ E҈ = E ᆠ 㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  턼 ᨨ犨矄ᨨ 泐 ᨨ鼀 ᨨ��   ᨨ盐�  ᨨᆠ├矄 ᆠ  ᨨ犨 ᨨ盐� 矄꾀 쟼  矄鼀 꾀

턼꾀

rrc dT s T  ᔼ �� � ᨨ  矄� 矄

ò  dt =

�䰘

\

�



rrc rrc é ҈ ù = s ò  T  s êë T  úû 

( ) (

)

\

sT 맔pR㦨҈맔pr ᨨ



ᨨ

T =

ᨨ

T =

⧤

 �⧤

턼ᔴ

턼 

턼쟼 쟼

RA =

L ҈ L  =  RB = =  K L㡰W KW K LW 㡰 KW

RC =

L ҈ L  =  RD = =  K  LW 㡰  KW �K LW 㡰 �KW

҈ L =  K  LW 㡰  KW ᨨ犨DT㦨QR 和� ᆠ   矄�矄 ᆠ ᨨ  ᨨ犨 �矄 矄 ᨨ 矄 E   鼀盐 �  ᆠᆠᨨ矄矄 E �矄 矄鼀矄 꾀矄ᨨ DTC DTC QC = = =  KW DTC 㡰 RC ҈⏌  KW DTB DTC  KW DTC 㡰 QB = = = ᲼Q DTB㦨DTC桌 RB  ⏌  KW  RE =

҈ ´ r  sR 

DTC �KW DTc 㡰 DTD = = ᲼Q DTD = DTC 桌 RD  ⏌ �KW   KW DTC 㡰 � KW DTC 㡰 QB + QD = +   KW DTC 㡰 = = KW DTC 㡰 = QC 

҈ ´ ҈� ´ ҈҈҈㡰 

QD =

 

�䰘 ´ ҈ 㡰 䰘 ´ ҈ 㡰

҈ ´ � ´ ҈

ᨨ T㦨�⧤ �䰘 ´ 黨 ´ ҈

  ⼄盐�  ᨨ҈ � ᨨ �ᆠ   ᔴ ᨨᆠ  � � ᨨ 犨 ᔴ㦨mL㦨҈맔맔㦨

  矄  泐� ᨨ  犨 � ᔴ ᨨ ᆠ  ��矄 鼀盐ᨨ ᔴ㦨mcDT㦨맔맔�㦨҈�  ᆠᆠᨨ鼀�ᆠ犨� ᨨ鼀矄ᨨ  � 鼀盐 ᨨ  鼀� 盐犨� ᔴ

l KA

  犨�   ᨨ 矄矄 ␔ 

和

T =

쟼 ⧤

␔├ ᨨ犨  鼀矄�矄 ᆠ 㦨

E

쟼 �泐 = sT  ´ pR  �鼀 쟼 �泐 ᆠ�  ᨨ     盐 ��鼀㦨҈맔pr



턼 

턼꾀 㦨턼 졔턼ᔴ 졔턼 㦨턼쟼

҈

҈ dT

rrc é ҈ ҈ ù t㦨 ê ú  黨s êë ҈㡰 㡰 úû 䰘rrc 䰘rrc » = ҈䰘҈rrc t㦨   䰘 ´ ҈ 㡰 s 䰘 ´ ҈ �䰘 ´ ҈ - 㡰  ᆠ �鼀 ⼄盐�  ᨨ   鼀盐 ᨨ    矄  ᨨ ᨨᨨ҈├㦨҈䰘҈rrc 꾀ᆠᆠᨨ � � ᨨ和  Ἐ矄 犨 쟼 �泐 �   盐 � �鼀 R 盐 �㦨sT  r \

⧤



  é ù êëQ m = r ´  pr  A = pr úû

Þ dt 㦨

t



⧤



�.e. QC㦨QB졔QD ᆠ 㡰 和� ᆠ 鼀盐ᨨ ᆠ├ᨨ 泐 ᆠ 鼀鼀� 矄 ᆠᨨ 矄  矄ᨨ  �泐鼀�  㦨  �泐矄ᨨ  泐ᆠ├ ᨨ 泐

WWW.JEEBOOKS.IN

PS-115

Thermal Properties of Matter 

b㡰 쟼 �泐鼀� 矄ᆠᨨ 泐ᨨ 泐A  B矄鼀 

\㦨eAs TA A㦨eBs TB A ҈⏌ 

æ eA ö ´ T 㦨҈黨⧤ \TB㦨 ç A è e ÷ø

҈䰘 = 黨� ├�\㝐矄矄ᨨ ᆠᨨ � 㦨黨�├� ҈   ᨨ矄 泐矄鼀 㦨  ��   泐犨 msL 盐矄㦨mwc DT ᨨ m =

Þ ms 㦨

B

꾀ᆠᆠᨨ � � ᨨ␔� Ἐ矄 �矄ᆠ鼀  犨 l m µ

҈ T

䰘

lm㡰ATA 㦨 lm㡰BTB

Þ

l m 㡰 A TB � = = l m 㡰 B TA ҈黨

 �㡰

和� ᆠ鼀盐ᨨ A�矄鼀ᨨ  ᨨ lm㡰A�矄矄矄 \ lm㡰B lm㡰A㦨҈맔҈鼀 �� 㡰  ��㡰 和ᨨ� �⼄ �㡰  ��㡰犨� lB㦨҈�맔҈鼀 

�

ᨨ矄泐矄鼀҈ ᔴᨨᆠ  �ᨨ҈ ᔴ犨 Q҈㦨 mL㦨�맔맔҈㦨҈҈ ᨨ矄泐҈ ᔴ犨ᨨᆠ  �ᨨ ᔴ犨 Q㦨MCDT㦨�맔맔҈㦨҈  ⼄盐�  泐� ├� ᨨ �ᆠ ᨨᆠ  � �矄 鼀盐 ᨨ鼀�K ᨨ䰘K Q㦨m맔C�ᆠ맔DT㦨�맔҈맔㦨҈黨 ⼄盐� 泐�├��ᆠ䰘⧤ᨨᆠᨨ � ᨨ� ├�犨䰘K Q㦨mL 盐矄�ᨨ 㦨�맔맔҈㦨҈�҈ ᨨ鼀   ᨨ   � �矄 ᆠ   Q҈ 졔 Q > Q 盐 Q҈졔QQ졔Q矄ᨨ犨 ᨨ�ᆠ犨� ᨨ鼀

 ᨨ  � 鼀盐犨�䰘⧤ᨨ ᔴ  m  鼀矄矄 ᨨ  ᆠᨨ �  꾀ᆠᆠᨨ � � ᨨ� ᆠ� ᨨ ᆠᨨ�鼀泐 ᨨ矄 㦨  ��

ᨨ矄泐ᆠᨨ � 㦨msdTᨨdQ㦨m A졔BT㡰dT Q



ᨨ

ò dQ = mò� ( A + BT ) dT

ᨨ

é BT  ù Q = m ê AT + ú  úû ëê �

ᨨ

é  ´ ҈ Q = m ê҈T +  ëê





mwcDT ҈ ´  ´  = 㦨҈├� L fus � ´ ҈ ´ 

  �泐鼀�   矄ᆠᨨ  泐ᨨ  矄 矄 犨�  矄鼀矄  鼀盐  矄盐 ᆠ 矄鼀 ␔├ ᨨ犨  Q = mcDT

dQ mcdT = dt dt 和� ᆠQ�矄矄鼀 c�矄矄ᨨ矄鼀 ᨨ ᨨ ᆠᨨ㡰

ᨨ

dQ ҈ µ dt m 㝐矄矄 ᨨ  ᨨᨨ犨 矄  �矄 矄矄 矄ᨨ ᨨᨨ犨 矄  犨� ᆠᨨᨨ 矄  ෌�  �奠 ᨨ     �矄 矄ᨨ  泐   ᨨ矄ᆠ

 ᨨ䰘�奠 �矄盐矄 � 鼀� �ᨨ  ᔼ ��鼀 㦨䰘 ᔴ 㝐� �ᨨ� ᨨ  㦨䰘 ᔴ\ D 㦨䰘䰘㦨 ᔴ \

䰘�㡰맔

҈ Mv  㦨McDT졔ML 

҈  䰘�㡰맔 v 㦨 맔졔㡰맔  v㦨҈黨鼀⏌矄 黨 �㡰 ᔼ ��ᨨ 㜠꾀 �矄 矄ᨨ 泐 鼀� ᆠᨨ 矄  鼀盐  �矄 盐矄  �   矄 ᆠ  �� � ᨨ鼀 矄ᨨ� ᨨ�⼄盐�  ᔼ  ��ᨨ  ᔴ �矄 矄ᨨ  泐 鼀�   ᆠᨨ 矄  鼀盐 �矄盐矄 �  矄ᆠ  �� � ᨨ鼀�⼄盐� ᨨ�矄 ��㡰   ᨨ ᨨ�矄�ᨨ 㦨   ᨨ  盐矄�ᨨ 㡰 ���㡰  矄ᨨ DE � �ᆠ矄     鼀盐 ᨨ    矄ᨨ�  �� 矄 ᨨ �矄 �㡰  矄ᨨ ᨨ 졠꾀 > 矄ᨨ ᨨ ᔴ �矄 � �ᆠ矄    �矄 �矄� 矄ᆠ� �ᆠ  䰘 ෌�  鼀ᆠᨨ 盐ᆠ��泐 KX 㦨黨ᆠ⏌矄ᆠ㜠ᆠ鼀㜠 ᔴ KY㦨ᆠ⏌矄ᆠ㜠ᆠ鼀㜠 ᔴ ᔴ ᲼ 桌 ᔴ

 

ù Tú ûú �

  é ) ´ ( �) ù ( ê ú ᨨ Q = m ҈ (   � ) + ҈ êë úû ᨨ Q㦨m᲼҈桌ᆠᨨ� ᨨQ㦨҈mᆠᨨ�  �㡰 ��  泐�ᆠ� 鼀� �㦨mL \Q҈㦨҈맔㦨ᆠ ��  泐犨ᨨ ᨨ�ᆠ㦨 msDT \Q㦨҈맔҈맔䰘㦨䰘ᆠ \ ᨨ ��  㦨졔䰘 Q҈졔Q㦨҈䰘ᆠ  ��㡰 \ᨨ矄㦨��  ᨨ҈m㦨҈䰘

꾀 ᲼ᨨᔴ桌

Ӹ

 

 ᲼ 桌 Ӹ 

쟼 ᲼҈ᨨᔴ桌

Ӹ ᲼ 桌

ᨨ鼀 ��盐

KY A  - TB 㡰 K X A TB - ҈㡰 KY A TB - ҈㡰 = + l l l 和ᨨ� � ᨨ⼄盐�ᨨ 犨�TB㦨 ᔴ ᨨ 犨� ᨨ犨 ᨨ盐� ᔴ 꾀矄C�矄ᨨ�  鼀� ᨨ 쟼  ᨨ鼀盐 TB + TE °C + ҈°C = = °C   和�鼀�泐鼀盐�矄矄ᨨ ᔴ

C =

WWW.JEEBOOKS.IN

EBD_8341 PS-116

Physics 

Topic-3 : Newton’s Law of Cooling ҈

T҈ - T éT + T ù = K ê ҈  - T ú t ë  û

犨  q �矄   鼀盐 ᨨ 矄盐ᨨ盐 � �

 ҈㦨� ᔴ 㦨 ᔴ    ᨨ㦨 ᔴ㦨和㦨�鼀� 盐矄

ᨨ犨 ᨨ犨ᆠᨨᨨ矄 ᨨ鼀 ᔴᨨ� ᔴ� ҈鼀� 盐矄

� -  æ � +  ö = Kç -  ÷ �㝐�

è  ø

 - � é  + � ù = -⧤ ê - q ú ҈  ë û

 �㡰

 - T æ  + T ö = Kç -  ÷ � è  ø �� � �⼄  ��㡰泐 �㡰犨�

� -  é � +  ù = -⧤ ê - q ú ҈ ë  û

 ��㡰



�� - q ҈ =   - q ҈ �� - q  =   - q 

 = °ᔴ 

 - ҈q =  - q q = 

æ dT ö  ÷ = esAT dt ø

æ dT ö çè - ÷ø dt B

q = ҈°ᔴ �

dT es ´ A ´ T  dT ҈ = Þµ dt r ´ Vᨨl ´ S dt rS

æ dT ö çè - ÷ø dt A



T Þ  - �T = T �

b㡰 ᨨ ᨨ矄矄㦨 mS çè

-

 ��㡰

�� � �⼄盐�ᨨ 矄 �㡰泐 ��㡰犨�

 - T  + T -  T = = ҈ � +  -  �

\T =

 �㡰

꾀�� �ᆠᨨᨨ矄 ᨨ鼀� ᔴᨨ ᔴ�   ҈鼀� 盐矄

 T    鼀盐 ᨨ 矄      � 鼀� 盐矄



Þ  - T =

泐 犨ᨨ 矄 犨 ᨨ  ᆠᨨᨨ� �

q҈ - q é q + q ù = -⧤ ê ҈ - q ú   ë û

b㡰 ᨨ鼀 犨ᨨ Ἐ矄 犨 ᨨ ᆠᨨᨨ� �

Þ

b㡰

ᆠ㡰 꾀ᆠᆠᨨ � �ᨨ犨ᨨ Ἐ矄犨ᨨ ᆠᨨ� � 鼀盐 �ᨨ矄 ᨨ  ᆠ矄� � 犨�  �鼀 ᨨ 㜠� 泐 Topic-4 : Miscellaneous (Mixed Concepts) Problems

҈

r S ҈  = B´ B = ´ r A S A  ´ ҈ 

㡰 ᨨ犨

P=

dQ d dT = mc 㡰T = H 㡰 dt dt dt d éT ҈ + bt҈  㡰ù û dt ë

æ dT ö æ dT ö Þ ç- ÷ > ç- ÷ è dt ø A è dt ø B

 = H 㡰

和ᨨ꾀ᆠᨨᨨ矄 ᨨ犨   矄  㡰 꾀ᆠᆠᨨ � � ᨨ犨ᨨ 矄 犨 ᨨ ᆠᨨᨨ� �

P = H 㡰T =

æ q҈ - q ö æ q҈ + q ö - q ÷ çè ÷ø = K çè ø t  æ  - � ö æ  + � ö - �÷ çè ÷ = K çè ø ҈ ø  æ � - q ö æ � + q ö - �÷ ÷ = K çè ø ҈ ø 

  çè

�� � �⼄ �㡰泐 ��㡰

҈  = Þ q = � ᔴ @  ᔴ � - q㡰 q

\

H 㡰 =

 �㡰

盐 t҈  =

 ��㡰

\

t  =

bt -  犨 H㦨 ᆠᆠ�泐 

 Pt   Tb

 �㡰

T t 㡰 - T bT

[T t 㡰 - T ] bT

 ��㡰

ᨨ鼀⼄ �㡰 ��㡰

 P [T t 㡰 - T ]  P [T t 㡰 - T ] =   Tb b T bT 

H 㡰 =



WWW.JEEBOOKS.IN

PS-117

Thermal Properties of Matter 

b㡰 ᔼ   �矄  ᨨᆠ�矄ᆠ  盐ᨨ矄矄盐 �   矄ᆠᨨ     ᨨᆠ�矄 盐 ᨨ矄盐 ᆠ  矄�ᨨ  T

턼 = s  × D

꾀  ᨨ犨 ᨨ鼀⼄ �㡰

P0 2R

FT h/2 P0 졔

h rg 2

鼀矄



= s꾀  -  㡰 

Þ

s꾀 ᲼  + D 㡰  -  桌 =  鼀矄

=





hrg ö éæ ù

 ᨨᆠ�矄 ê ç P + ÷ø ´  R ´ h㡰ú -  RT è  ë û \ ᨨᆠ㦨PRh졔RrghRT 㡰 ␔  矄 �ᆠᨨ 泐�矄├� 矄�  ᆠ泐ᆠ├ ᨨ 泐     ᨨ   �  泐   ᨨ 泐�矄 ⼄盐 ᨨ   ᨨ    ᆠ├ ᨨ 泐 ᔼ  �矄⼄盐矄�ᨨ  �� ᨨ�ᨨ 矄犨ᨨ �矄  ᨨ盐 ᨨ�ᨨ 矄 ᆠᨨ �  e� ᆠᨨ s ᆠ㡰 ᨨ  ��  鼀矄矄 ᨨ �矄  ᆠᨨ 矄  矄矄盐

ᨨ

턼 = s  × D

꾀  和� ᆠ  ᨨ  ᨨ矄矄 ᨨ   㦨  ᆠ�   矄ᆠᨨ 䰘㦨 ⧤⏌꾀㡰 鼀矄㡰D

᲼⧤맔鼀矄㦨맔҈桌

DV ҈ ҈ = d ᨨ dT = ҈ = ᨨ T T V DT

 ⼄盐�ᨨ  矄 矄  ᆠ �盐 泐ᨨ ᨨ    ᨨ鼀xy㦨c �ᆠ 泐�  c㡰

�

黨㡰  ᔴ

l

҈ ᔴ

䰘



ᨨh ᨨ犨 ᨨ鼀ᨨ

dQ҈ dm҈ KA  = Lf = lx dt dt ᨨh ᨨ犨 ᨨ鼀ᨨ



 �㡰

é æ D ö ù 턼 = s  + D 㡰 -  㡰 = s  êç҈ + ÷ - ҈ú 꾀 

 ø êè ú ë û

éæ D ö ù = s  êç҈ +  ÷ - ҈ú

 ø úû êëè

 é ù ҈ ö  æ ê AT ҈ s + - ҈ú t  ç 㦨 ÷ êëè T ø úû

é  ù



 㦨 sAT ê T ú ´ t =  ´҈´  ´҈ = ҈J ë û

P=

쟼 �泐 � = sAT  - sAT  �鼀

dp



Þ

ᆠ㡰 쟼 �泐 �  泐  ᨨ 泐㦨 sA T  - T  㡰  ᲼ ᨨᆠ├ᨨ 泐㦨҈桌 㦨 sA᲼  + ҈㡰 - T  桌t

 �㡰

dm҈ dm ù dQ dm KA  é = = = Lvap  ��㡰 ê ෌�  ë dt dt úû dt ҈ x - lx dt �� � �⼄ �㡰泐 ��㡰 矄ᨨ� �犨�l㦨黨 㡰 ᨨ ᨨ矄矄 ᨨ  

턼 = s 꾀  -  㡰 

䰘 ´ 꾀 䰘 ´ � ´҈ - � � = = = ⧤ ´ 鼀矄   ҈ - ´  \ D 㦨 Þ D =

 ҈ l

 ù s꾀  éêæ D ö ú

 ´ ç ҈ + ҈ ÷ 鼀矄

 ø êè ú ë û



= ⧤D 錐  æ ö s꾀  ᔴᨨ 矄  ᨨ 犨ᨨ Ἐ矄 犨 ᨨ ᆠᨨᨨ� � ÷ ç⧤ = ç ÷ 鼀矄 è ø  ⧤ Þ s꾀  = 鼀矄㡰 꾀 ᨨ鼀⼄ �㡰

ᨨ

 ᔴ

᲼Q 턼㦨鼀矄D 桌

s꾀  =

 × D

 鼀矄

V V + DV V \ = 㦨 ᔴᨨ 矄  T T + DT T VT졔VDT㦨VT졔TDV ᨨ VDT㦨TDV



 ��㡰

 \ dT = sA T 㡰 \ dp = sA T 㡰 dT 

\ DP = sAT 矄 盐鼀 ᨨ 泐�矄 ᨨᆠ├ᨨ 泐和ᨨᨨ�ᨨ  㡰 㡰  � ᆠᨨᆠ 쟼 �泐 �  µ꾀  犨  꾀 �矄   矄盐 ᆠ  ᨨ   ᨨ 泐  ᆠ ᨨ�ᨨ  ᆠ㡰 �矄 ᆠᨨᆠ

WWW.JEEBOOKS.IN

EBD_8341 PS-118

Physics

Thermodynamics

11

ᨨᆠᨨ 矄� �泐�矄 㦨 kx kx \ P = P҈ +  꾀㦨ᨨ ᆠᨨ矄矄矄ᆠ�ᨨ ᨨ �矄ᨨ 㡰 ��㡰 A ␔  V㦨V҈T㦨T҈

Topic-1 : First Law of Thermodynamics ҈



㡰 D鼀� 矄矄鼀 ᨨᨨ   矄꾀ᔴ 꾀 D턼꾀ᔴ㦨D␔꾀ᔴ졔D꾀ᔴ Þ 㦨졔D꾀ᔴ Þ 꾀ᔴ㦨 \ D꾀㦨D꾀ᔴ㦨 D턼꾀㦨D꾀졔D␔꾀 㦨҈졔㦨 㡰 ᨨ盐鼀ᨨ 犨 ᨨ矄 ᨨᆠ  � ᨨ犨ᨨ├�矄 ᨨ ᨨ

ᨨ泐 矄泐矄鼀 ␔㦨㡰 꾀ᆠᆠᨨ � � ᨨ �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄

\

盐� � �矄盐ᨨ P� ⼄  ��㡰犨� PA kx  P҈ = P҈ + Þ kx = ҈ A   V  V҈ V҈  ҈ V҈ x= = = A A A 쟼 �泐矄ᨨ  �    矄� � PV ҈ ҈ = kx  = ( kx )( x ) = ҈ ҈    㡰 ᔴ  � �  �    �泐

턼 㦨  졔 ␔ 



�



䰘

ᨨ ᔼ矄ᨨᆠ ᨨ�ᆠ ᨨᆠ矄矄 턼 㦨   D㦨mᆠ 㦨맔҈맔㦨҈䰘├ 㡰 꾀矄 犨├ ᨨ犨 ᔼ矄 犨 ᨨ   鼀ᨨ 泐 鼀�ᆠ矄㡰 D턼 = D盐 + D犨 Þ D턼 = D盐 + D ᨨ ҈� = D盐 + ҈ (҈ -  ) 㦨 D盐 - ҈ \  D盐 = ҈� + ҈ = �

盐矄   �   �泐ᨨ    �矄 � ᆠ矄矄 泐�  㡰 ᨨ鼀  �矄犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄 dQ㦨dU졔dW dW㦨 �� 㡰 \ dQ㦨dU ᨨ犨矄� ᆠdQ �� 㡰 �, dQ �矄 �� 矄ᨨ dU ᆠ矄矄 ᔼ   �泐ἘUἘ ᆠ矄犨  鼀盐T ᆠ矄矄 㡰 꾀泐� � �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄 ᨨ  � Q�af㦨DU�af졔W�af �㦨DU�af졔 \DU�af㦨 ᨨ犨 Q�bf 㦨 DU�bf 졔 W�b 졔 Wbf 㦨졔�졔҈ Q�b 졔 Qbf㦨�  �㡰 꾀矄ᨨ Q�b = DU �b + W�b \Q�b㦨҈졔�㦨҈�  ��㡰 Qbf Q�b g  Q�b  = = = ᨨ鼀⼄ �㡰 ��㡰 Q�b Q�b ҈� ᔴᨨ 矄 㡰ᔼ  �矄  矄�ᨨ  ᨨ犨ᨨ├�矄 ᨨ ᆠ盐矄  �矄  矄 ᆠᨨ 矄 � ᆠ盐盐鼀\DW㦨  꾀矄ᨨQ㦨矄 ᨨᆠ矄矄�矄 ��ᆠ ᆠ ᨨ鼀 �矄犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄DU㦨  �.e., 鼀盐 鼀� 矄 ᆠᨨ 矄  bᆠ㡰  矄� � �矄 ᆠᨨ鼀矄矄  泐x ᨨ  � �   �矄 P҈ PV Ἐ ҈ἘT҈

x



P ἘV ἘT kx

kx

x + x

㡰 꾀矄 �矄 �矄 �  鼀ᨨ ᨨᨨ鼀�ᆠ PV PV ҈ ҈ =   \ T҈ T

PV ҈ ҈ = P ´ ( V҈ ) Þ P =  P  ҈ T҈  T҈

f æ ö PV  PV ( ҈ ҈ ) = ç P҈ ´ V҈  PV ҈ ҈ ÷ 㦨P҈V҈ ø  è ᆠ㡰 꾀�� 犨  V㦨V҈ T㦨T҈ 

ᨨ鼀⼄  �㡰 P ( V ) PV  ҈ ҈ =  ҈ Þ P = P҈ T҈  T҈ V V V x=  ҈ = ҈ A A ᨨ鼀⼄  ��㡰 PA  kx P҈ = P҈ + Þ kx = ҈   A ␔ᨨ├ ᨨ  泐�矄 㦨 ␔ᨨ├ ᨨ  泐�矄 ᨨ  鼀ᨨ矄 졔 쟼 �泐矄ᨨ  �  矄� � ҈ ҈ æ P A ö æ V ö Wg = P҈ Ax + kx  = P҈ ( V҈ ) + ç ҈ ÷ ç ҈ ÷  è  øè A ø ҈ 䰘 PV =  PV ҈ ҈ + PV ҈ ҈= ҈ ҈   㡰 DQ㦨Wg졔DU 䰘  = PV ҈ ҈ + ( PV  PV ҈ ҈)   䰘 æ ö = PV ҈ ҈ + ç P҈ ´ V҈  PV ҈ ҈÷ ø  è bᆠ㡰

�矄 ᆠ矄� ᨨ盐鼀 盐� �鼀� �ᨨ  �ᆠ矄  䰘 ⧤  ᨨ �� 犨ᨨ├ �矄 ᨨ  泐�ᆠ㜠犨 矄泐矄鼀ᨨ  鼀ᨨ矄 ᨨᨨ矄��犨ᨨ├�矄 ᨨ ᨨ   �ᆠ㜠犨 矄泐矄鼀 泐  鼀ᨨ矄   ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ 和ᆠᨨ 泐  �矄 矄ᨨ  盐� � 鼀� � � dQ �矄 ᨨ矄��㡰   矄 犨  矄  犨ᨨ├ ᨨ  泐�ᆠ㜠犨 矄泐矄鼀 �矄 �� dW �矄 ��㡰  ᨨ ᨨ鼀 �矄 犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄dU㦨dQdW ᆠ  �� �   �泐ᨨ �ᆠ㜠犨矄泐矄鼀dU 犨�  ᨨ矄��ᨨ �    �泐犨� � ᆠ矄 DU =



 �㡰

WWW.JEEBOOKS.IN

PS-119

Thermodynamics 黨

҈

꾀㜠錐㜠錐ᔴ㜠⼄矄錐㜠 꾀㡰 ᨨᆠ矄矄꾀® 

�矄 �矄   �矄ᨨ�ᆠᨨᆠ矄矄 P 㦨 ᆠᨨ 矄    ᨨ盐鼀 㡰 ᨨ   �矄 ᆠ矄矄  ᨨ 犨ᨨ├ �矄 ᨨ  ᨨ    �矄 ␔㦨 㡰㦨 꾀矄ᨨ V ᆠ矄矄 矄ᨨ 鼀盐   ᆠ矄矄 \ ᔼ    �泐  ᆠ矄矄 ᨨ鼀 Q㦨 U졔 W矄 U ␔  ᆠ矄矄 矄ᨨ Q ᆠ矄矄   鼀 矄  �矄 ᨨ矄 㡰ᨨᆠ矄矄®ᔴ

�矄�矄 �矄ᨨᆠ ᨨ�ᆠᨨᆠ矄矄V㦨ᆠᨨ 矄 矄矄盐 ᆠ矄矄 P µ T 矄ᨨ 鼀盐 矄ᨨ ᆠ矄矄 W㦨錐DU㦨 ��矄ᨨDQ ��  ᆠ  �矄 ᨨ矄 ᔴ㡰ᨨᆠ矄矄ᔴ®

�矄 �矄 �矄ᨨ�ᆠ 矄矄盐 P 㦨 ᆠᨨ 矄  V � ᆠ矄矄  VµT矄ᨨT� ᆠ矄矄 ᆠD␔D D턼졔矄ᨨ  ��   泐  �矄 㡰ᨨᆠ矄矄®꾀 꾀泐� �㦨

黨 PV ᨨ 黨㡰㦨҈ \ 㦨 R 黨 PV ᨨ꾀 㡰㦨҈ 꾀\ 꾀㦨 R � ᨨᆠ矄矄�矄�矄ᨨ 鼀\ D㦨 ᨨ犨D턼㦨D졔␔\ D턼㦨␔ 꾀矄 ᨨ盐鼀 ᆠ矄 �   �矄 ᨨᆠ矄矄 矄ᨨ W �� � 犨ᨨ鼀 ᨨ ᨨ  �矄 DQ ��  ᆠ �矄ᨨ矄 꾀㡰㜠 ⼄㡰  꾀矄  �  �矄   矄 �  ᆠ盐盐鼀     ᆠᨨ � �矄� 矄盐   ᨨW㦨Q㦨 ᆠᆠᨨ � � ᨨ �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄 D㦨턼졔␔ Þ D㦨  ᆠ �矄 ᨨᆠ  � �   鼀盐ᨨ  �矄 ᨨ T �矄 ᆠᨨ 矄  㡰㜠 㡰෌�  P µ

PV PV� ᆠ矄和ᨨT nR � ᆠ矄矄 ᨨ盐鼀 � ᆠ矄矄 矄ᨨ W � ᆠ矄矄 ᨨ鼀Q㦨DU졔WQ� ᆠ矄矄  ᆠ   �矄 �� 矄  ҈҈ ᨨ鼀   ��  PV �  ᔼ  ᨨᆠ矄矄 J ® K ᨨ盐鼀 V 㦨ᆠᨨ 矄 p�矄 ᆠ矄� � PµT  ᨨT矄 ᨨ盐 矄ᨨ ᆠ矄 \W㦨Pdv㦨DV㦨DQ ��㡰 ᨨ鼀 DQ㦨DU졔DW ᔼ ᨨᆠ矄矄K®L p㦨ᆠᨨ 矄 㦨nCvDTV�矄� ᆠ矄� �和ᨨ 鼀盐 矄 ᨨ盐  矄ᨨ� ᆠ矄 \DW㦨Pdv>DU㦨nCvDT > Q㦨mCDT> ᔼ ᨨᆠ矄矄L®M V㦨ᆠᨨ 矄 P� ᆠ矄矄ᨨT� ᆠ矄矄 \W㦨DU> Q> ᔼ  ᨨᆠ矄矄 M®J V�矄 ᆠ矄� �\DW T�矄矄ᨨ ᆠ矄� �\ DU DQ ҈ ᆠᨨ矄ᨨ � �㜠� ᨨ    꾀  ��  㜠 �  �矄 矄 ᨨ犨  �  ��盐 ᨨᆠ矄矄꾀®꾀矄�� � � V㜠T � � �ᆠ矄VµT\ 矄矄盐�矄 ᆠᨨ 矄  ᨨ  V  ᔴ T � ᆠ矄� �  ᨨᆠ矄矄®ᔴᨨ盐鼀�矄ᆠᨨ 矄 和� ᆠ 鼀盐 �矄 ᆠ矄� � 和ᨨ 矄矄盐犨� 矄ᨨ ᆠ矄 ᨨᆠ矄矄 ᔴ ® 꾀  鼀盐 �矄 ᆠᨨ 矄  盐 ᨨ盐鼀 I ᆠ矄矄  ᆠ 矄矄盐 犨� � ᆠ矄 矄 P µ  V 㡰㜠 ⼄矄㡰 ᨨ鼀PV㦨nRT ÞT㦨

Topic-2 : Specific Heat Capacity and Thermodynamical Processes ҈

҈

ᨨ 㦨ᆠᨨ 矄  V ᨨ nRTV 㦨 ᆠᨨ 矄  \맔 㦨ᆠᨨ 矄  꾀矄 �矄  矄�矄ᨨ盐鼀� ᆠ矄矄矄ᨨ鼀盐 ᆠ矄矄 ␔├ ᨨ犨 턼㦨 ᔴD  �㡰 ᨨ  ᨨ泐ᨨ�ᆠ ᨨᆠ矄矄 ᔴ㦨ᔴ졔   㦨ᆠᨨ 矄  ҈㜠

㦨ᔴᨨ 矄  \ 㦨  \ᔴ㦨ᔴ졔 㦨ᔴ 㦨  㦨 ҈㜠    턼㦨 ᔴD 㦨 맔 맔D   �D �矄 �� Q�矄 ��矄ᨨ �矄ᨨ矄 꾀矄 ᨨ盐鼀 � ᆠ矄矄 矄ᨨ 鼀盐 ᆠ矄矄 ��

҈ P µ ⏌  Þ PV ⏌  㦨 ᆠᨨ 矄  V  \n㦨      - \ᔴ㦨ᔴ졔 㦨 졔 㦨  㦨   -҈   ҈ æ - ö \턼㦨nCVDT㦨 ç ÷ Δ è  ø 꾀矄D �矄 �� 턼 �矄 ᨨ矄�� 和ᨨ �矄 �� 矄 

b㡰 鼀盐ᆠ  �DT�矄矄鼀 ᨨ ᨨᆠ矄矄矄 A ® B錐 A ® C   A ® D DU = nCv DT 㦨矄鼀

E AB = E AC = E AD



␔ᨨ├ ᨨ  W = P ´ DV AB ® ᨨ盐鼀�矄� ᆠ矄� � Þ WAB >  AD ® ᨨ盐鼀�矄 ᆠ矄� � Þ WAD <  AC ®  ᨨ盐鼀�矄 ᆠᨨ 矄  Þ WAC =  ᆠ㡰 ᔼ   ��ᆠ ᨨᆠ矄矄 PV g = ᆠᨨ 矄  g æ mö æmö \ P ç ÷ = ᆠᨨ 矄  çèQ V = r ø÷ èrø 꾀矄 鼀矄矄 �矄 ᆠᨨ 矄 

\ P µ rg

ᔼ P� Pf � ��  � 矄矄盐ᨨ  �矄 r�   r f  � ��  �   矄�泐ᨨ  �矄 

g Pf æ r f ö 䰘⏌� =ç ÷ = 㡰 P� è r� ø nP Þ � = � 㡰䰘 ⏌� = 䰘 P�

Þ n = 䰘 = ҈

 

b㡰 盐矄� � ᨨ  �盐鼀 ᨨᨨ  �矄 �矄�   �   �矄 ᨨᆠ矄矄 DQ =   矄ᨨ  ��ᆠ 㡰 ᨨ鼀 ᆠᨨ矄ᨨ � �㜠 � �� � ⼄盐矄�ᨨ  ᨨᆠ矄矄 xy ® ᔼ矄ᨨ�ᆠ   矄�ᨨ  ᨨᆠ矄矄 yz ® ᔼ矄ᨨᆠ ᨨ�ᆠ 矄矄盐 ᆠ矄矄㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-120

Physics

ᨨᆠ矄矄 zx ® ᔼ矄ᨨ 鼀 ᆠᨨ鼀矄矄�ᨨ

 ᨨ ᆠᨨ矄ᨨ � � PV�  �矄 矄 矄 ᨨ犨  �  ��盐

҈

҈҈

�

b㡰 ෌� V҈㦨҈�P҈㦨҈鼀 V㦨�g㦨҈ g g 矄� �PVr㦨 ᆠᨨ 矄  Þ PV ҈ ҈ = PV ҈

æ҈ö Þ P = P҈ ´ ç ÷ è ø

҈ atm ��� PV  PV \␔ᨨ├ ᨨ  W = ҈ ҈ g ҈ ҈ æ ö ´  ÷҈҈� ´ ҈� ´ ҈  ç҈´҈  ��� ø è = 㦨黨҈J  

=

\ = ҈�

҈

g ҈

Þ T µ V ҈+  盐矄� � �㡰

Þ T

҈+g µV 

҈+g

҈+g æ V ö  Þ =ç ÷ = 㡰  T� è V ø b㡰 DUᆠ㦨 DUᆠ㡰㦨 ҈㡰㦨҈ Q㦨�졔㦨҈ ᨨ犨Q㦨DU졔W ᨨ ҈㦨҈졔W ᨨ W㦨҈ ᆠ㡰 꾀矄   ᨨᆠ矄矄 �矄 �矄ᨨᆠ ᨨ�ᆠ 矄ᨨ 䰘  턼 = ᆠ  DT = ´ ´  = 黨 = 黨 ´ ҈ ; 䰘    b㡰 ␔  �� 

Tf

黨

҈

V

 �㡰 T 쟼⼄盐�ᨨ  ᨨ   ��ᆠ ᨨᆠ矄矄 �矄 TVg҈ 㦨 ᆠᨨ 矄  ҈ Þ T µ g-҈ V



҈

ᔴᨨ矄矄盐ᨨ W㦨黨�J ᨨ 盐矄㡰␔├ ᨨ犨   �ᨨ �鼀



䰘

҈

ᆠ㡰 ᔼ   �泐  矄ᨨ 泐ᨨ � ��  � 矄 和ᨨD꾀㦨D 꾀矄ᨨD턼㦨D졔␔ 꾀矄␔꾀>␔Þ D턼꾀 >D턼 b㡰 和盐ᨨ矄 鼀ᨨ盐  ᨨ  犨 ᨨ   㝐 �鼀

  ҈�㝐㡰�鼀犨ᆠᨨ  � ᨨ�ᆠ 矄ᨨ ᆠᨨ 矄盐鼀 � ᨨᨨ�ᨨ 㦨矄 �  盐矄�ᨨ

㝐맔㦨 ҈�㝐㡰맔矄 㝐맔҈맔҈㦨 ҈�㝐㡰맔맔҈� Þ㝐㦨� 㡰  ® ᔼ矄ᨨ矄�ᆠ  ® ᔼ矄ᨨ 鼀 ᆠ ® 꾀 ��ᆠ  ® ᔼ矄ᨨᆠ ᨨ�ᆠ b㡰 ᨨ 犨ᨨ├ ᨨ 泐  �矄 盐� �  ᆠ泐ᆠ �矄 ⼄盐 ᨨᨨ � �꾀ᔴ ҈ \ D␔ = ´  ´ � = ҈   b㡰 쟼⼄盐�ᨨ  ᨨ  ��ᆠ ᆠ  � �矄

g-1 㦨 ᆠᨨ 矄  䰘 䰘 盐 g = 犨� g - ҈ = - ҈ � �

 �

b㡰 ␔ᨨ├ ᨨ 

҈ ␔㦨D㦨 D 㦨 ´ ҈´ 䰘 ; 黨҈  㡰 쟼⼄盐�ᨨ ᨨ  ᔴ   =  -   -  㡰  盐矄� �㦨

鼀盐 =

=

  -

   +    ҈´ Q 㦨҈鼀ᨨ�� 㡰

 é   ù ê� ú êë  úû



 � = Þ�=  Þ  =    

 é �  �  ù �  

=  ê� ´  ´  ú = ë   ҈ û  ҈䰘 ᆠ㡰  ⼄盐�ᨨ  ᨨ  �  �矄

é ҈ æ V ö ù P = P ê҈ - ç  ÷ ú êë  è V ø úû

 ᨨ

é

҈ù

P

␔  ҈㦨 Þ ҈㦨 ê҈ - ú = ë û  ␔  㦨 é ҈ æ ҈ ö ù æ 䰘 P ö Þ 㦨 ê҈ - ç ÷ ú = ç ÷ ë  è  øû è  ø PV P V é PV ù DT = T - T҈ = ҈ ҈ -   êQ T = nR nR ë nR úû æ ҈ ö æ ҈ ö æ PV 䰘 PV ö DT = ç ҈ ҈ - PV 㡰 = ç ÷ PV ÷ç nR  ÷ø è ø è nR ø è  �P V �P V =   =   Qn㦨҈㡰  nR R

ᆠ ᨨ

q ᨨ

ᨨ

q ᨨ ᨨ

-   +   졔㦨 盐 㦨



\㦨  㦨

ᨨ



᲼矄ᨨ㦨

- ᆠ㦨桌   �㡰  ��㡰

WWW.JEEBOOKS.IN

PS-121

Thermodynamics



졔㦨   \ 졔 㦨 ���㡰

ᨨ鼀盐ᨨ鼀 �鼀盐鼀 㦨  �  �� �⼄ ���㡰泐�犨�

 졔 㡰㦨 

\  㦨 

  -   㦨 㦨 

  P 㦨 ᲼ ᨨ鼀 �㡰桌 \ P=    黨  \ 鼀 㦨 ᲼ ᨨ鼀 ���㡰桌  㡰 쟼 �ᆠ� ᆠ泐ᨨ    ��  �矄 ��  泐 ᔴ 犨  㦨 ҈㜠  㦨 㦨 㦨 h㦨 � 턼 ᔴ ᔴ �  Qᔴᔴ㦨 㡰 � ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ �矄 ᔴ  㦨   ᆠ㡰 Q PV r = ᆠᨨ 矄  � �㦨ᆠᨨ 矄 Þ�⏌㦨ᆠᨨ 矄 \ g =  ᨨ鼀 �㡰 ��㡰

҈

҈黨

 

 

�



ᨨ   犨ᨨ 矄 ᨨᆠ矄矄

(

)



)

W = p� V f  V� = ҈� 䰘 ´ ҈  = 䰘 ´ ҈ 

(

)

҈ æ҈ f  ö Pf V f  PV çè ´ ҈ ҈ ÷ø � � =  g ҈    黨  D U =  ´ ҈ =  ´ ҈      ᨨ鼀 �矄犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄 QW㦨DU 䰘  黨  ´ ҈   = � \ Q = 䰘 ´ ҈  ´ ҈ =   ҈  㡰 t =  æ ö 

2p  ç ÷ èø 㝐  tµ

꾀矄 g҈㦨⧤ 和ᨨtµg졔҈⏌ g +҈

 ᨨ ⼄ 㦨  DU =





҈æU ö 㡰 꾀矄 P = ç ÷ èV ø   盐 = ⧤

 ҈  和ᨨ  = ⧤

 盐 ҈ = ⧤  ᲼꾀矄㦨盐 桌 ᨨ      p = ᆠᨨ 矄   ҈

 ᨨ µ b㡰 ᔼ  VT � 㜠ᨨᆠ矄矄  ᔼ矄ᨨ�ᆠ 鼀盐 � ᆠ矄矄 ᆠ ᨨᆠ矄矄  꾀 ��ᆠ 矄矄盐 ᆠ矄矄 ᆠ  ᨨᆠ矄矄  ᔼ矄ᨨ�ᆠ ᨨ盐鼀 ᆠ矄矄  ᨨᆠ矄矄  꾀 ��ᆠ 矄矄盐 � ᆠ矄矄

 ᨨ ᨨᆠ矄矄矄 ᆠᨨᆠ泐 矄   �  P㜠V ��鼀 㡰 㡰 ᔼ ᆠ泐ᆠ�ᆠᨨᆠ矄矄ᆠ  �� ᨨ�   �泐�矄 ᨨ Dᆠ泐ᆠ�ᆠ㦨 �R DT Dᔴ㦨 nCv DT = ҈ ´  ␔  ᔴ 㦨 鼀ᨨ 矄ᆠ� �ᆠ   ᆠᨨ 矄  ᨨ盐鼀 ᨨᔴD 㦨⧤ \ Dᔴ㦨� ᆠ㡰 ෌� 犨ᨨ├ ᨨ W㦨 ᨨᨨ 鼀ᨨ矄ᨨ �矄m㦨 ᨨ �ᨨ鼀�ᆠ�矄g㦨҈ ␔ᨨ├ ᨨ  盐� �    ��ᆠ ᆠ  �

mR T҈ - T 㡰 g -҈  ´  DT 㡰  ´  DT 㡰 Þ 㦨 㦨 ҈ - ҈   ´  㦨⧤ Þ DT㦨  ´  � b㡰 ᨨ盐鼀ᨨ  �矄 鼀 =   矄� �  g = ᆠᨨ 矄  W㦨

 ��ᆠ

(



҈

��

�

҈

Ἐ  æ Ἐö = =ç ÷  Ἐ è ø



g

ᨨ҈㦨 㡰g 䰘 \ g = = ҈ � 㡰 ᔼ ��泐 ᨨ盐鼀  ҈ 㦨 �l 鼀盐 㦨 T҈  � g = ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ �矄㡰  �l ҈

 盐鼀ᨨ 鼀ᨨ矄ᨨ �矄 n = = l  � 泐   ��ᆠᆠᨨ鼀矄矄�ᨨ 㡰㦨䰘l ᨨ  ��ᆠ ᨨᆠ矄矄 T҈V҈g-҈ = TV g-҈

æ V҈ ö \ T = T҈ ç ÷ è V ø

g -҈





æ � ö  ⏌  = T҈ ç ÷ 㦨 T҈ 㡰 = T҈ è 䰘 ø

WWW.JEEBOOKS.IN

EBD_8341 PS-122

䰘

Physics

␔ᨨ├ ᨨ  �   ��ᆠ ᨨᆠ矄矄 ҈ R T  T҈ ] nR DT  [ ҈ 黨 = = RT҈ W= � g -҈  é ù êë  ҈úû b㡰 ᔼ   �矄ᨨᆠ矄矄WAB�矄졔矄DV�矄ᨨ矄���   矄ᆠᨨ ᨨᆠ矄矄 WBC�矄矄 DV�矄  盐    ᆠ盐 ᨨ 矄ᆠᨨ  ᨨᆠ矄矄 �矄 鼀ᨨ \ ␔ᨨ├ 矄ᨨP>P҈ C

P

꾀 ��ᆠ

P1

A

ᔼ矄ᨨ 鼀 B

P2

黨



�

b㡰 ᨨ鼀   P  T �  犨 �  AB ᨨ   �矄ᨨ 鼀 ᨨᆠ矄矄AC�矄 ��ᆠᨨᆠ矄矄�� 꾀矄ᨨ ᨨ   矄�ᨨ

ᨨᆠ矄矄   矄ᨨᨨ  ��ᆠ ᆠ盐 �矄 鼀ᨨ ᨨ犨 ᆠ  矄泐   盐  PV �  ᨨ�矄ᨨ 鼀ᨨᆠ矄矄 �矄 鼀ᨨ   ��ᆠᨨᆠ矄矄 ᨨ矄鼀� ᆠ矄�  ᨨ盐鼀㡰  ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄 ᆠᨨ矄ᨨ � �    �  㡰 ᨨ ᆠ泐ᆠ�ᆠ ᨨᆠ矄矄錐 Qᆠ泐ᆠ�ᆠ㦨WAB졔WBC졔WCA㦨҈졔졔WCA㦨� \ WCA㦨� b㡰 ᨨ  ��ᆠ ᨨᆠ矄矄 PV g 㦨 ᆠᨨ 矄  꾀矄ᨨ ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄�├ �盐鼀g㦨҈䰘 ᨨ �ᨨ鼀�ᆠ�矄�├ᨨ 泐� g㦨҈

g-҈

æV ö = TV Þ T҈ = T ç  ÷ è V҈ ø V҈  T҈ = T�  T = aT� g㦨҈ ᨨ �ᨨ鼀�ᆠ�矄㡰 V =  ҈ -҈  aT é҈ù é҈ù \ T� = aT� ê ú = aT = � \㦨  �ê �ú  ë  û  ë û  㡰 ᨨ  ��ᆠ ᨨᆠ矄矄 TV g -҈ =  ᆠᨨ 矄  ᨨ T҈V҈g -҈ = TVg -҈ 䰘 V T҈ = °ᔴ + 䰘 = 黨 ⧤  V = ҈   g = � ҈

⏌�

䰘

\ T҈V҈g ҈ = TVg ҈ ҈ -҈

æ ö çV ÷ Þ T = 㡰 ´ ç ҈ ÷ Þ T㦨맔 ҈㡰 çç V҈ ÷÷ è ҈ ø ᔼ �矄⼄盐�ᨨ  PV㦨 nRT

nRT P Þ V 㦨 kT 矄� ᆠ 矄矄盐 �矄 ᆠᨨ 矄  ᨨ �矄ᨨ�ᆠ ᨨᆠ矄矄㡰 和ᨨ 盐� � �矄ᨨ�ᆠ ᨨᆠ矄矄 V㦨kT  �㡰 㦨kTf  ��㡰 �� � � �㡰泐 ��㡰 ҈ T =  Tf

V



⏌

 dPV dV ᨨ  �矄ᨨ 鼀 ᨨᆠ矄矄錐 PV 㦨 ᆠᨨ 矄  \ PdV졔VdP㦨 dP =K \ P㦨 盐├鼀ᨨ 盐盐矄㡰 dV ⏌ V

b㡰 盐├鼀ᨨ 盐盐矄K㦨

盐� �   ᨨᆠ矄矄 ᆠ  � �  �    �泐 � DU = NCV DT = � ´ ´  ´  ;  ´ ҈ 㦨 X ├  \ X =   ҈҈㡰 ᨨ    ��ᆠ ᨨᆠ矄矄

g҈ 㦨 ᆠᨨ 矄 

\ V=

和� ᆠg �ᨨ鼀�ᆠg鼀ᨨ ᨨᨨ鼀�ᆠ \P �ᨨ鼀�ᆠ>P鼀ᨨ ᨨᨨ鼀�ᆠ  ᆠ�  ҈ �矄 ᨨ �ᨨ鼀�ᆠ�.e. ᨨ 泐�    �   �矄 ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�.e. ᨨ �盐鼀 㡰 ␔ᨨ├ ᨨ  �矄 ⼄盐 ᨨ  盐    ᆠ盐 ᨨ  PV ��鼀 ᆠ ᨨ鼀  ��鼀w>w҈>w 㡰 ᨨ鼀TVg҈ 㦨 ᆠᨨ 矄  � ᨨ鼀ᨨ ᨨ鼀�ᆠ�矄 g㦨   ᆠTV⏌ 㦨 ᆠᨨ 矄   ⏌ ⏌ Q VµL㡰 \  T҈ L҈ = T L

æL ö T  ᆠ ҈ = ç  ÷ T è L҈ ø

g -҈

æ ҈ö Þ 黨 = T ç ÷ Þ T = 黨 ҈㡰 ⏌ � ; 䰘 ⧤ è ҈ ø DT = 䰘 - 黨 =  ⧤

҈ 



g-҈

æV ö T҈ V҈ 㡰 g -҈ = T ç ҈ ÷ è ҈ ø

P

҈

㡰 犨ᨨ├ ᨨ  盐� � ᆠ泐ᆠ㦨 ᆠᨨ矄 �   PVᆠ盐 㡰 ᨨ    ��ᆠ ᨨᆠ矄矄 泐� � TVg҈ 㦨 ᆠᨨ 矄 

T҈V҈g-҈



V1







Tf㦨T㦨맔맔 ҈㡰㦨҈҈K ҈䰘䰘ᨨ ҈䰘㡰  �  ҈ ᨨ鼀ᨨ ᨨ鼀�ᆠ�矄 g =   ҈⏌ ᔼ   ��ᆠ ᨨᆠ矄矄  P҈҈g 㦨g

Þ



҈

҈



҈ ҈㡰�⏌ =  ҈ 㡰�⏌ 

WWW.JEEBOOKS.IN

PS-123

Thermodynamics

Þ  =

�⏌

҈ æ ҈ ö  çè  ÷ø

=

҈ ҈



ᆠ㡰 PV� ᨨ  �� VT� �矄�� ᨨ犨 

 ҈҈ - ҈ ҈ 㡰 ҈҈ -   ҈ = 꾀 ␔ � = � g -҈ -҈     ⏌ 㡰 黨 = ҈ ҈ = ҈҈ ⏌  ᔼ  �矄ᨨ 鼀 ᨨᆠ矄矄

㡰 ҈



 㡰

 

黨 

҈





⧤쟼 = ᔴ鼀� ´ 

ᨨ鼀T҈V҈g҈㦨TVg҈ ᨨT㦨T҈ 㡰⏌�㦨T

\ ⧤쟼 = ᔴ鼀� ´  =  

 

㡰 ␔ᨨ├ ᨨ  盐� � ᆠ泐ᆠ�ᆠ ᨨᆠ矄矄 ҈®®®҈㡰 W

  㦨  ᆠᨨ矄 �  ᨨᨨ =

    = Q 㦨 \  

  = \ ␔ᨨ├ ᨨ W = [ 矄 = ҈] ҈ 

㡰 ᨨᆠ矄矄҈®�矄�矄ᨨ�ᆠ ᨨᆠ矄矄 ® �矄 �矄ᨨᆠ ᨨ�ᆠ ᨨᆠ矄矄®�矄�矄ᨨ�ᆠ ᨨᆠ矄矄 ® ҈�矄 �矄ᨨᆠ ᨨ�ᆠ  ᆠ ᨨ ��ᆠ ᨨᆠ矄矄 �矄 �鼀ᨨ  ᆠ㡰  D턼҈®  =  ᔴ D  =  ᔴ (   -  )  =  ᔴ  

 D턼 ®  =  D   =  ᔴ  D  =  ᔴ    ᔴ � D턼҈® \ = = D턼 ® ᔴ  

 㡰 D턼®  = ᔴ 



 D턼҈®   \ = =

 ҈ D턼®

ᔴ 



b㡰 ᨨᆠ矄矄꾀ᨨ TA㦨TB\UA㦨UB 꾀矄ᨨPV㦨맔V

WAB = nRT ᨨ� e

�

V 

V

P  ␔ᨨ├ ᨨ  Þ PB =

҈

æ ö ҈ \  =  ç  ÷ =  (  )  è ø 㦨 㡰҈㦨㦨黨 ␔ᨨ├ ᨨ  盐� �   ᨨᆠ矄矄   - ҈ ҈ 黨 ´  ⏌ 㡰 -   ҈  ␔=   = = ҈- g ҈ - ҈  盐㦨  矄 㦨�졔҈㦨㡰 ҈ (   ) \ ␔= = -҈  \␔㦨҈RT 

�⧤쟼ᨨ  �矄鼀� 盐

 㡰

 㡰 

æ ö ␔�矄ᨨ㦨m  ᨨ�҈ ç  ÷ è ҈ ø æ  ö Þ ␔�矄ᨨ㦨҈҈  ç ҈ ÷ = ҈҈ ᔼ  è ҈ ø ␔   ᔼ  ҈ \ �矄ᨨ = ҈ ҈ =   =   黨 ␔ � 黨 ҈҈  ҈ 和ᨨ = =҈䰘䰘䰘 »҈䰘 黨 �㡰 ᨨ  ��ᆠ   矄�ᨨ

P P PVg㦨Pa맔 V㡰g Þ Pa㦨 g = ҈䰘   ᨨ �矄ᨨ 鼀   矄�ᨨ

P P맔V㦨P�맔V Þ P�㦨  Pa   P = ´ = \ 㦨 P� ҈䰘 P ҈䰘 T盐㡰  矄ᨨ ᨨ  P㜠V ᆠ盐 �矄 鼀ᨨ  ᨨ  ��ᆠ ᨨᆠ矄矄    ᨨ �矄ᨨ 鼀 ᨨᆠ矄矄 ᨨ鼀   �  � �矄 ᆠ 矄ᨨ ᨨB�矄�   矄ᨨ ᨨA. 和ᨨ  �矄ᨨ 鼀 ᨨᆠ矄矄 �矄 矄   泐  ᆠ盐 A b 㡰 꾀 ��ᆠ ᆠᨨ 矄  ᨨ   �矄 鼀� 盐 � 䰘

҈ᔴ҈ +  ᔴ � ´  + ҈ ´  g鼀 = = = ҈

҈ᔴ ҈ +  ᔴ � ´  + ҈ ´ �   ᨨ   ��ᆠᨨᆠ矄矄 Pv g 㦨 ᔴᨨ 矄 



V

V V



꾀 T

T

㦨 PV ᨨ�   ᲼Q P0V0 = nRT0 桌

 ᨨᆠ矄矄 ᔴ �矄 ᨨ ᆠ  ᨨ ᨨ 盐 �鼀  ᆠ

鼀 C� � �P T b 㡰 㡰 ᨨᆠ矄矄AB�矄 ᨨ�矄ᨨ 鼀ᔼ ᆠ矄ᨨ  �矄ᨨ 鼀 ᨨᆠ矄矄 犨� ᆠ �盐 泐ᨨ�  㜠 ��鼀 㡰 ᔼ ᨨᆠ矄矄®ᔴ®D�矄 �� ᆠ矄矄   ᨨ盐鼀矄ᨨ ᆠ矄矄  ᨨ␔ �矄 �� ᨨ鼀 �矄 犨 ᨨ   鼀ᨨ 泐 鼀�ᆠ 턼 �矄 �� �   �矄   ᨨ矄矄

WWW.JEEBOOKS.IN

EBD_8341 PS-124



Physics ᔼ 턼҈®㦨 ᔴD ҈®㦨 ᔴ  �㡰

ᆠ㡰 ␔ 꾀  > ␔ ᔴ   ᨨ 犨ᨨ├ ᨨ  盐� �  꾀®®ᔴ�矄ᨨ矄�� 㡰 ␔ᨨ├ ᨨ �矄ᆠᨨᆠ├犨�矄ᆠ泐ᆠ�  ��鼀�矄ᨨ矄�� bᆠ 㡰 㡰 ᨨ 鼀ᨨᆠ矄矄矄ᆠ  ��矄�   �泐�

 ᆠᨨ 矄  矄矄盐ᨨᆠ矄矄

� é   㡰   ù = ҈´ ê  ᲼Q㦨 桌  ë úû � � æ ö �  =   = ç  ÷ =  è  ø  \ ᔼ

DU = nCv DT 犨  DT = (T - T҈ )

b㡰 꾀ᆠᆠᨨ � � ᨨ �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄

DQ = DU + DW

䰘

ᔼ     ��ᆠᨨᆠ矄矄 DQ =  ᨨ  = DU + DW ᨨ DU = DW ᆠ㡰 ᔼ  �矄ᨨ 鼀ᨨᆠ矄矄 DT =  \ DU㦨 Q DU㦨nCvDT 㡰 ᔼ    ��ᆠᨨᆠ矄矄 DQ =  㡰 ᔼ㡰 꾀 �b�ᆠᨨᆠ矄矄 ᨨ ᆠ  �ᨨ  ├矄 ᆠ 犨�  矄盐ᨨ盐 � �矄

黨

ò P × dV = 

 ᆠ 犨ᨨ├ ᨨ  �矄 ᨨ ᔼ㡰 ᔼ  �矄ᨨ�ᆠ ᨨᆠ矄矄 矄矄盐 鼀� 矄 ᆠᨨ 矄  W = P × DV ¹  f f DU = nR DT = ᲼ P DV 桌 ¹   

\ DQ = nC p DT ¹ 

 ҈ ᲼Q  =  �� 桌   \ ᔼ®턼 ᔼᔼ D҈®®㦨D҈®졔D® 㦨 ᔴD ҈®졔 ᔴD ®   = ҈´ - � 㡰҈® + ҈´ ᲼ - � 桌®     é  ù ´  -  ´  ú 㦨 ᲼  -   桌 + ê  ë  û ҈ 㦨㦨맔 RT 㦨RT  ᔼᔼ® ᔼᔼᔼ 턼҈®®㦨턼҈®졔턼® 㦨 ᔴD ҈®졔 ᔴD ® �  é  ù =   + ҈ ´ ê  ´  -   㡰 ú  ë  û

      = ´ =      ᔼᔼᔼ和 =

  l  +  = l  [Q D҈®  =  ]   ᔼ ᆠ㡰 ᨨᆠ矄矄 ᔼ�矄 ��ᆠ  ᨨD턼 㦨  ᨨᆠ矄矄ᔼᔼ�矄�矄ᨨ�ᆠP㦨 ᆠᨨ 矄    ᨨ␔㦨 ҈㡰 㦨 㡰㦨 ᨨᆠ矄矄 ᔼᔼᔼ�矄 �矄ᨨᆠ ᨨ�ᆠV㦨 ᆠᨨ 矄    ᨨ ␔㦨 ҈㡰㦨 ᨨᆠ矄矄ᔼ�矄�矄ᨨ 鼀鼀盐T㦨ᆠᨨ 矄 \D盐㦨 㡰 ᆠἘ矄 ᆠᨨᆠ�ᨨ ᨨ   矄 ᨨ 矄ᨨ盐 � �  �矄 �矄   ᨨ  ��ᆠ ᨨᆠ矄矄 PVᆠ盐�  ��ᆠᨨᆠ矄矄�矄矄  �矄ᨨ 鼀 b㡰 ␔ᨨ├ ᨨ  �  �矄ᨨᆠ ᨨ�ᆠᨨᆠ矄矄 �矄 ᨨ ᨨ 犨 �ᆠ  犨 ��ᆠ� � 㜠� �  s㡰 㡰 D㦨D턼D W㦨PDV㦨P VV҈㡰㦨PV졔PV҈ 犨 �ᆠ  �矄   ᨨ鼀盐 ᨨ �矄ᨨ�ᆠᨨᆠ矄矄 矄ᨨ�  P㡰 㡰 ␔෌쟼㦨 㡰㦨҈ ␔෌㦨 㡰㦨 Pf Vf  PV � � P  㡰 -   㡰 ␔ 㡰 ��ᆠ = 㦨 = � ҈ g ҈ æVf ö æV f ö ␔ ෌㡰�矄ᨨ 鼀 = nRT  ç ç V ÷÷ = PV  çç V ÷÷ è � ø è � ø

=

㡰 ᔼ ␔҈®®㦨␔҈®졔␔® ᲼␔®㦨DV㦨桌 㦨맔졔졠

=   =

éQ = ҈  ␔ ® �矄ᨨᆠ ᨨ�ᆠ ù ê ú ë ᨨ ᆠ  � � ᨨ盐鼀 D =  û

\ ᔼ ᔼᔼ D҈®®㦨D҈®졔D® 㦨 졠 + ᔴ D = D [ ᨨᆠ矄矄҈ ® �矄ᨨ 鼀�ᆠD 㦨] 

 ö  æ = ҈´ ç  - ÷ =  ᲼ ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄 㦨桌  è  ø \ᔼᔼ ᔼᔼᔼ 턼҈®®㦨␔҈®®졔D҈®® ᨨ鼀 �矄 犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄  = l  +    = [ l  + ]  \ᔼᔼᔼ

ᔼ 턼҈®㦨␔҈®졔D҈®

ᔼᔼ㡰 ᔼ矄ᨨh鼀 ᨨᆠ矄矄  鼀盐 鼀� 矄 ᆠᨨ 矄  f \ DT =  Þ DU = nR DT Þ DU =   ᨨᆠ  �� �   �泐᲼DU㦨桌 ᔼᔼᔼ㡰 ᔼ矄ᨨᆠ ᨨ�ᆠ ᨨᆠ矄矄 ᨨ盐鼀 鼀� 矄 ᆠᨨ 矄 



Vf

+ Pdv V�

 = ҈  l  + ᨨ   RT =     㦨nRT 

Þ DQ = 

DV =  Þ W =

ᆠ㡰 ᔼ ␔҈®® = ␔҈® + ␔-

�

�҈

� �

�

WWW.JEEBOOKS.IN

PS-125

Thermodynamics

  㦨ᨨ��㦨҈ᨨ� 㡰 �矄   ᆠᨨᆠ ᨨ�ᨨ

㡰 ᨨ鼀DQ㦨msD

DQ  DT = = = �°C ms ҈ ´  æ ҈ ö � 㡰 DT = V gDT = çè ÷ 黨 ´ ҈ ( �) 黨 ø 㦨�맔҈䰘鼀 \W㦨pDV㦨 ҈㡰� �맔҈䰘㡰㦨� 㦨҈ 㡰ᨨ�

��

(

)

ᆠ㡰 DU = DQ  W = (   �) J = ҈黨黨黨黨黨� J �

VB

ò

V 㦨 ᆠᨨ 矄  ᔼ矄ᨨ�ᆠ ᨨᆠ矄矄㡰 T VA VB \ = TA TB é VB ù V = ú Þ TB㦨 B ´ TA 㦨맔㦨K êQ VA ë VA û 㡰  矄ᨨ  ᨨ 矄 ᔼ ᨨᆠ矄矄 Aᨨ B �矄  �矄ᨨ�ᆠᨨᆠ矄矄㡰 � \ Q㦨nCpDT㦨맔 R ´  㦨҈�R  � é ù êQ C p =  R ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ �矄 ú ë û  �矄 矄ᨨ  ᔼ ᨨᆠ矄矄 Bᨨ C �矄   �矄ᨨ 鼀 ᨨᆠ矄矄㡰 \ ᔼ   �泐ᆠ  �dU㦨 Q DT㦨 \ ᨨ鼀 �矄犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄dQ㦨dW Vf \ Q㦨맔nRTᨨ�҈ V� 㦨맔맔R맔맔ᨨ�҈ 㦨䰘맔ᨨ�҈맔R㦨҈R 矄ᨨ 㡰 ᔼ ᨨᆠ矄矄 C ᨨ D �矄 �矄ᨨᆠ ᨨ�ᆠᨨᆠ矄矄㡰 dW㦨Q dV㦨 æ ö \ Q㦨nCvDT = n ç R ÷ ( TA - TB ) è ø  R 㦨맔 맔 㡰㦨黨R 矄 㡰  ᔼ ᨨᆠ矄矄 D ᨨ A �矄ᨨ 鼀 ᨨᆠ矄矄㡰 Vf \ Q㦨맔nRTᨨ�҈ V� æVf ö 㦨맔R맔맔ᨨ� ç ç V ÷÷ 㦨҈R è � ø  �矄 矄 ᆠ㡰 ᨨ 犨ᨨ├ ᨨ  W㦨QA®B졔QB®C졔QC®D졔QD®A 㦨 ҈�R졔҈R㡰 黨R졔҈R㡰㦨R 㡰 盐鼀ᨨ 鼀ᨨ矄n㦨T҈㦨⧤ 盐� � ᨨᆠ矄矄꾀®  pT㦨 ᆠᨨ 矄  ᨨ pV㦨 ᆠᨨ 矄  㦨 K 矄泐㡰 \

p=

K V

VB

K V

dV

㦨  K VB  VA 桌 㦨 ᲼ KVB  KV A 桌 㦨 ᲼

( P V )V  B B

B

( P V )V  A A



A桌

㦨᲼PBVBPAVA桌 㦨᲼nRTBnRTA桌㦨nR ᲼T҈T҈桌 㦨 㡰 㡰 R㡰᲼桌㦨҈R \ ␔ᨨ├ ᨨ ᨨ  �矄 �  ᨨᆠ矄矄 AB �矄 ҈R 꾀  鼀hᨨ 

㡰 ᔼ  �� V㜠T� AB�矄矄�� �  \

�䰘

ò

\ WA® B = p  = VA VA





P҈





҈





T҈



pV㦨nRT \ pdV 졔 Vdp = nRdT

( nRT )

dp = nRdT  �㡰 P ᨨ鼀   ��  ᆠᨨ ��ᨨ

pT 㦨 ᆠᨨ 矄  pdT졔Tdp㦨  ��㡰 ᨨ鼀쟼⼄矄 �㡰  ��㡰犨� pdV㦨nRdT ᨨ pdV 졔

\ WA® B =

ò

pdV = nR

TB

òT

dT = nR TB  TA 㡰

A

㦨nR T҈T҈㡰㦨 㡰 㡰 R㡰 㡰 ᨨ WA® B = ҈ R 㡰 ᨨ 㦨ᔴᨨ 矄㝐ᨨ ᆠᆠ�泐 R R R R C= + = + � ҈ g ҈ ҈ x ҈ ҈   㦨ᆠᨨ 矄 ᨨ҈⏌㦨ᆠᨨ 矄  ҈ \x =  Þ C = �R 턼꾀®㦨 ᔴD 㦨 � 㡰 㡰㦨҈ ᨨᆠ矄矄 ᔴᨨᆠ矄矄 �矄 �矄ᨨ�ᆠ æ� ö 턼®ᔴ㦨 ᔴD 㦨 㡰 çè R ÷ø  ᔴ 㡰  æ� ö 㦨 çè R ÷ø  ҈ ҈㡰㦨 � 㡰 㡰㦨҈�   �矄 矄ᨨ ᨨᆠ矄矄 ᔴ 꾀ᨨᆠ矄矄 �矄 �矄ᨨ 鼀

æ PC ö è PA ÷ø

D 㦨\D盐㦨和ᨨ턼ᔴ®꾀㦨␔ᔴ®꾀㦨 ᔴ ç

æ P҈ ö 㦨 㡰 㡰 㡰 㡰㦨҈ 맔黨 㦨  ҈㡰 ç è P҈ ÷ø 턼ᔴ®꾀㦨҈  矄ᨨ 㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-126

�

Physics

n㦨 ᨨᨨ 鼀ᨨ矄㦨 꾀㡰 ᆠᨨ鼀ᨨᆠ矄矄ᨨ 㜠 ��鼀�矄矄 ᨨ犨 ᨨ犨 



 ᔴ � �ᆠᨨ 矄  ᨨ盐鼀   꾀 ��ᆠ ᆠᨨ鼀矄矄�ᨨ





҈



㡰 �㡰 ᨨ犨ᨨ├ ᨨ  W㦨WAB졔WBC㦨



ᔼ矄ᨨᆠ ᨨ�ᆠ ᨨᆠ矄矄㡰 

PV ҈ ҈ - PV 㡰 + g - ҈㡰 ᲼Q WBC㦨PDV㦨P맔㦨桌 g

æV ö 꾀ᆠᆠᨨ � �ᨨᨨ�矄矄ᨨ Ἐ矄 犨P㦨 P҈ ç ҈ ÷ è V ø g ù æV ö ҈ éê P҈V҈ - P҈ ç ҈ ÷ V ú \ W㦨 g -҈ ê ú è V ø ë û g -҈ é V҈ æ V҈ ö ù æ ҈ ê �ö P҈V҈ - P҈ V   ç ÷ ú çQ g = ÷ 㦨 ø g -҈ ê V è V ø ú è ë û ⏌ é æ V ö ⏌ ù æ V҈ ö ù   éê ҈ ú P V P V P V W㦨 㦨 ҈ ҈ ê҈ - ç ÷ ú ÷ ҈ ҈ ҈ ҈ç V  ê V ê ú è  ø úû  è ø ë ë û ��㡰 ᨨᆠ  �� �   �泐DU㦨DUAB 졔DUBC 㦨QW é æ V ö ⏌ ù  P V 㦨Q ҈ ҈ ê҈ - ç ҈ ÷ ú  ê è V ø ú ë û ᲼ᆠᆠᨨ � � ᨨ �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄桌 é B ® C Q = DU BC +  ù ê A ® B Q = DU + W ú AB ë û ���㡰 ᨨᨨᆠ矄矄BCDUBC㦨nCvDT㦨Q ᲼Q WBC㦨桌  R = R ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄Cv㦨 g -҈  Q R DT ÞDT㦨 \ DUBC㦨Q㦨맔  R  꾀ᆠᆠᨨ � � ᨨᨨ�矄矄�ᨨ Ἐ矄 犨  g -҈

ᨨ  ᨨᆠ矄矄 AB TAVB

æV ö ᨨ TB㦨TA ç ҈ ÷ è V ø

�黨

g-҈

g -҈

= TBVB

PV æ V ö = ҈ ҈ç ҈ ÷ nR è V ø

g-҈

P g ҈-g PV � ⏌ V- ⏌  \ TB㦨 ҈ V҈ V = ҈ ҈ R R � ⏌  - ⏌  PV V Q  ᆠTC㦨TB졔DT㦨 ҈ ҈ + R R 盐鼀ᨨ 鼀ᨨ n㦨҈ ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄 Cp㦨

�R R  Cv =  

㡰 ␔ᨨ├ ᨨ 泐 �矄 w㦨 꾀 ᨨ DABC ҈ ҈ W㦨 맔矄맔 �� 㦨 V맔P㦨PV   㡰  ᆠ  泐  �矄 �      CA � �矄ᨨ�ᆠ ᨨᆠ矄矄 DQCA㦨nCpDT㦨҈맔 �R⏌㡰 TA TC㡰

PV  PV  TA =   I ´R I´R � R é PV  PV ù � = - PV DQCA 㦨 ê ú  ë R  R û  矄ᨨ  泐  �矄 �      AB �.e �矄ᨨᆠ ᨨ�ᆠ ᨨᆠ矄矄 DQAB㦨nCvDT㦨҈맔 R⏌㡰 TBTA㡰 R é PV PV ù = PV 㦨  êë ҈ ´ R ҈ ´ R úû ᆠ㡰 꾀矄DU 㦨  �  ᆠ泐ᆠ�ᆠᨨᆠ矄矄  ᆠ ᨨ鼀 �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄DQ㦨DU졔DW \ DQ㦨D␔ DQAB 졔DQCA졔DQBC㦨DW PV PV DQBC㦨PV   =     é  P ù 㡰 쟼⼄盐�ᨨ  ᨨ� BCP㦨 ê ú V졔�P ë V û (Q y = mx + c ᨨ P = mV + C )

TC㦨

RT ᲼ ᨨᨨ 鼀ᨨ桌 V P \ RT㦨  V  + �PV V P㦨

ᨨ鼀 �鼀盐鼀錐

 �㡰

P dT =   -  맔V졔�P㦨錐 V dV

�V  ��㡰   ᆠ ᨨ鼀⼄盐�ᨨ  �㡰  ��㡰

\ V㦨



- P æ �V ö æ �V ö ´ç + � P ç  ÷ RT鼀 㦨 è  ÷ø è  ø V � �PV � PV + = 㦨PV맔 ҈   � PV \ T鼀 㦨  R V VA  = ҈ C =   ෌�   VB VB TA㦨KTB㦨䁸TD㦨䁸h㦨䁸 n㦨҈ ᨨ �ᨨ鼀�ᆠ�矄g㦨҈ ᨨ  ��ᆠᨨᆠ矄矄 A®B g -҈ = TBVB g-҈ æV ö ᨨ TB = ç A ÷ TA è VB ø



g -҈ TAVA

 꾀 

= ҈㡰

⏌�

´  = 黨黨 K

\ ᨨ �矄ᨨ�ᆠ ᨨᆠ矄矄 B ® C 矄矄盐 㦨 ᆠᨨ 矄  VB VC æV ö = ᨨTC㦨TB ç C ÷ 㦨黨黨᲼桌㦨҈҈K TB TC è VB ø

WWW.JEEBOOKS.IN

PS-127

Thermodynamics ᨨ ��ᆠᨨᆠ矄矄C®D VA V V = Q  A = ҈   C = 錐 \ VC VB VB g -҈ TCVC

҈

= TDVDg -҈

ᨨᨨ 鼀ᨨ矄n㦨҈R㦨҈ 鼀ᨨ҈k҈TA㦨҈⧤

g -҈ ҈҈ é҈ù é VC ù = 㦨䰘黨҈K \ TD㦨TC ê ú 㦨҈҈ êë  úû 㡰҈⏌ � ë VD û ᨨB®Cᨨᆠ矄矄矄ᨨ Q҈㦨nCp TC TB㡰 gR 䰘 ⏌ �㡰 R TC - TB 㡰 = ҈ ҈҈ - 黨黨㡰 㦨 n g -҈  ⏌ �㡰 䰘R ´ 黨黨 @ ҈ R 㦨  ᨨD®Aᨨᆠ矄矄 矄 R T - TA 㡰 Q㦨nCv TDTA㡰㦨n g -҈ D �R R ´ 黨҈ 䰘黨҈ - 㡰 = 㦨 ҈  ⏌ �㡰  Q ᨨ  �矄  ᆠ  �  �   ��ᆠ ᨨᆠ矄矄矄㡰 nR T - TA 㡰 ᨨ犨WAB㦨 g -҈ B �R R ´ 黨 黨 - 㡰 = 㦨  ⏌ �㡰  WBC㦨nR TCTB㡰㦨҈맔R ҈҈黨黨㡰㦨黨黨R nR R TC - TD 㡰 = + ҈҈ - 䰘黨҈㡰 WCD㦨 g -҈  ⏌ �㡰 �R ´ ҈䰘 㦨  �R �R W 㦨黨黨R졔  ҈䰘黨㡰㦨黨黨R졔 맔҈   㦨黨黨R졔҈�R㦨҈黨�R ҈黨� R \ 쟼 �ᆠ� ᆠ泐㦨҈맔 W ⏌Q҈㡰㦨҈맔 㦨҈奠 ҈ R � �㡰 T�㦨䰘졔䰘㦨K錐g㦨  ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄㡰  和� ᆠ   �矄   矄  ��ᆠ泐 矄ᨨ 盐矄� � ⏌�

T�V�g -҈ = T f V fg -҈



�㡰 WAB  ��ᆠ ᨨᆠ矄矄㡰

nR᲼TA - TB 桌 g -҈ g ҈g ᨨ鼀T P 㦨ᆠᨨ 矄 

WAB㦨

g ҈-g

TA PA

g ҈-g

= TB PB

æP ö Þ ç A÷ è PB ø

҈-g

g-҈

g

æT ö = ç A ÷  �㡰 è TB ø ҈-� ⏌ 

éP ù g é ù �⏌ Þ TB㦨TA ê A ú 㦨�⧤  = ҈ ê ú ë û ë PB û ҈ ´ ҈᲼҈ - �桌 \ WAB㦨 㦨҈䰘 �⏌ -҈ ��㡰 Hᨨ矄� hᨨᆠ矄矄 ® ᔴ�矄ᨨᆠ ᨨ�ᆠᨨᆠ矄矄 QBC㦨nCvDT㦨nCv TBTC㡰 P P

ᨨ � TC犨盐矄 B = C  ᨨ盐鼀V㦨ᆠᨨ 矄 㡰 TB TC ҈ é ù ê PC  PA ҈ ú PC ҈ ´ TB = ´ � = � K êQ = = ú Þ TC㦨 PB  ê PA  PA  ú  ë û  \ Q㦨҈맔 맔҈᲼��桌㦨�黨  ���㡰 ᔴ® 꾀® ��ᆠᨨᆠ矄矄矄 g

æ T ö҈ g P \ PC҈  gTCg = p҈D  gTDg Þ C = ç D ÷ PD è TC ø

 �㡰

PA҈ g TAg = p҈B  g TBg g

æ T ö҈ g P Þ A =ç B÷  ��㡰 PB è TA ø 㝐盐�泐� �쟼⼄矄 �㡰  ��㡰犨� g

g -҈

�⏌ -҈ æV ö éV ù = ҈黨 K Þ Tf㦨T� ç � ÷ 㦨  ê ú çV f ÷ ë V û è ø ��㡰 ␔ᨨ├ ᨨ  �矄  ��ᆠ ᨨᆠ矄矄 -nR T - T҈ 㡰 - ´ ҈ ҈黨 - 㡰 = W㦨 g -҈ �⏌  -҈ + ҈ ´ ҈҈҈ ´  = + 䰘䰘 㦨  꾀ᆠᆠᨨ � � ᨨ �矄 犨 ᨨ  鼀ᨨ 泐 鼀�ᆠ矄 DQ㦨DU졔DW 盐DQ㦨 矄   ᨨᆠ矄矄 �矄  ��ᆠ㡰 \ DU㦨DW㦨䰘䰘 ���㡰 ␔ᨨ├ ᨨ 泐 �矄 W㦨䰘䰘  꾀 ෌� TA㦨҈⧤  ҈ PB㦨 PA 錐PC㦨 PA    

CP � = g㦨  ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄㡰 CV 

PC PA æ TDTB ö҈ g =ç ÷ PD PB è TC TA ø ᨨᆠ矄矄矄®ᔴ ®꾀�矄ᨨᆠ ᨨ�ᆠ V 㦨 ᆠᨨ 矄 㡰 PC TC P T =  A = A

 ᨨ PB TB PD TD 㝐盐�泐� �  矄 犨ᨨ ⼄盐�ᨨ 矄 犨 � PC PA TC TA =  �㡰 PB PB TB PB ᨨ鼀쟼⼄矄 ���㡰  �㡰犨  g

g

æ TC TA ö҈ g æ TC TA ö æ TD TB ö҈ g æ TC TA ö =ç =ç ç ÷ ÷ ᨨ ç ÷ ÷ è TB TD ø è TD TB ø è TB TD ø è TC TA ø TC TA =҈ Þ TD TB



ᔴ 

WWW.JEEBOOKS.IN

EBD_8341 PS-128



Physics

TC TA ( �)(҈) = ᨨ TD = TB � ᨨ TD㦨�⧤ ᨨ   ᆠ泐ᆠ�ᆠ ᨨᆠ矄矄 ��

ᨨᆠ矄矄 㜠ᔴ QBC = nCP TC TB㡰

҈ ö æ䰘 ö æT = ( ) ç R÷ ç A  TA ÷ =  RTA è øè  ø  㦨��RTA ᨨᆠ矄矄ᔴ㜠꾀㦨ᆠᨨ 矄  \WCA㦨 ᨨQCA㦨DUCA㦨nCV TATC㡰

 鼀

҈鼀









⧤

⧤



Wᨨ├ ᨨ  ᨨᨨᆠ矄矄AᨨB ᔼ矄ᨨb�ᆠᨨᆠ矄矄㡰 WAB㦨nR TBTA㡰 㦨nR맔҈㦨맔맔㦨҈ Wᨨ├ ᨨ  ᨨᨨᆠ矄矄CᨨD ᔼ矄ᨨb�ᆠᨨᆠ矄矄㡰 WCD㦨 WAB 㦨҈J 㦨҈nR㦨맔㦨҈ Wᨨ├ ᨨ  ᨨᨨᆠ矄矄BᨨC ᔼ矄ᨨh鼀ᨨᆠ矄矄㡰

PB WBC㦨nRTᨨ�҈ PC  㦨nR맔ᨨ�҈ 㦨䰘䰘nR ҈ 㦨��맔㦨҈ Wᨨ├ ᨨ  ᨨᨨᆠ矄矄DᨨA ᔼ矄ᨨh鼀ᨨᆠ矄矄㡰 WDA㦨nRTᨨ�҈



PD ҈ 㦨nR맔ᨨ�҈ PA 

㦨䰘黨nR 㦨҈�맔㦨�黨�

ᨨ犨ᨨ├ ᨨ W㦨WAB졔WBC졔WCD졔WDA 㦨҈҈� 㡰 ᨨ鼀 �矄犨ᨨ  鼀ᨨ 泐 鼀�ᆠ矄DU㦨QW ᨨᆠᨨ鼀ᆠ泐ᆠDU㦨 \ Q㦨␔㦨҈҈� 㡰 犨ᨨ├ ᨨ W㦨҈҈� ᆠ㡰 DU㦨和� ᆠ ᨨᆠ矄矄�矄ᆠ泐ᆠ�ᆠ�DT㦨 㡰 p㜠V  p㜠T ��鼀矄 矄 ᨨ犨  ᨨ犨 P PA PA 

P PA

A

C VA

( pV ) A

B

PA 

VA

A C

TA 

B

VA

TA   㡰 ᨨᆠ矄矄 A㜠B T 㦨 ᆠᨨ 矄  ҈ \ P µ V �矄 ᨨ盐 矄ᨨ p 犨�ᆠᨨ鼀   V nRTA RTA 꾀矄ᨨ VA = = PA PA DU AB = 

( pV )C =

Þ\ TC =

æ V ö \ Q AB = WAB = nRTA ᔼ ç A ÷ è VA ø 㦨RTA�  㡰㦨RTA

�

T ö æ� öæ 㦨 㡰 ç R÷ ç TA  A ÷ = 䰘�RTA è øè ø ᔼ   ᆠ泐ᆠ�ᆠ ᨨᆠ矄矄 DU㦨 \Qnet㦨QAB졔QBC졔QCA㦨�RTA �㡰 ᨨ ��ᆠᨨᆠ矄矄 g  ҈ 㦨 ᆠᨨ 矄  T TV g -҈ = � V 㡰 g -҈  Þ 㦨 �㡰g ҈ 

├� �ᨨ�ᨨ ᨨ 矄� 矄ᨨ�㦨 g҈㡰ᨨ�� \ g㦨҈ 盐g㦨҈졔

   Þ ҈㦨҈졔 f f

 = �  �ᨨ   ᨨ鼀㡰  ��㡰 ᨨ  ��ᆠ ᨨᆠ矄矄 ᨨ犨 盐矄� � PVr 㦨 ᆠᨨ 矄  Þ f㦨 g

g

PV ҈ ҈ = PV

P ҈҈ �㡰 ␔ᨨ├ ᨨ  ᨨ  ��ᆠ ᨨᆠ矄矄 æ P ö PV - ç � V 㡰 è ҈҈ ÷ø PV P V ҈ ҈   = 㦨҈�PV W㦨 g -҈ ҈ - ҈  꾀泐� ��  �矄 ⼄盐�ᨨ  PV 㦨 nRT Þ P㦨

P

҈

=

PV ҈ ´ ҈6 ´  ҈ 㦨�鼀ᨨ矄 = = RT  ´   �R R ෌�  Cp 㦨  \ Cv =   黨맔҈ᨨ   �泐�矄矄盐� ᆠᨨ 矄 ᨨ盐鼀  ᆠ ᨨ鼀 Q㦨nCvDT Q 黨 ´ ҈ = \ DT㦨 㦨䰘�⧤  nCv � ´ ´   \ � 鼀盐㦨졔䰘�㦨䰘�⧤ ᨨ犨 ᨨ鼀෌泐盐矄矄ᆠἘ矄犨 P҈ P P҈T =  Þ P㦨 T҈ T T҈ \ n㦨

҈ ´ ҈ ´ 䰘� 㦨맔҈鼀  䰘 ᔼ   ��ᆠ ᨨᆠ矄矄  犨ᨨ├ ᨨ  ҈ ᲼ P V - PV 桌 ␔㦨 ҈- g   ҈ ҈ P҈㦨҈�⏌鼀V҈㦨 l 㦨맔҈鼀 =

WWW.JEEBOOKS.IN

PS-129

Thermodynamics g

æV ö P㦨P҈ ç ҈ ÷  V㦨 l 㦨맔҈ è V ø  � ෌� Cv㦨 R  \Cp㦨 R ᲼Q C p - Cv = R桌   g=

\

Cp Cv



= ҈䰘 ҈䰘

éù 㦨҈�맔 㡰҈䰘㦨맔҈�⏌鼀 ë û ҈ \ W㦨 ᲼맔҈�맔맔҈҈�맔맔҈桌 ҈ - ҈䰘 \ P㦨҈� ê ú 

҈ � 㦨黨䰘҈ ᲼҈�桌㦨 䰘 -䰘  �� 矄��  � �ᆠ矄     �矄 �矄 ᆠᨨ鼀矄矄  W㦨

Topic-3 : Carnot Engine, Refrigerators and Second Law of Thermodynamics ҈



P

҈㡰

B

C

P

P

D

A

V

V

V

ᨨ鼀  ��盐 ␔ᨨ├ W =  PV  ��  Q� = WAB + WBC = n × CV DTAB + nCP DTBC R n� R TB - TA 㡰 + TC - TB 㡰 =n  

R �R ö æ  CP = çèQ Cv = ÷  ø

 � = PBVB - PAV A 㡰 + PCVC - PBVB 㡰    � = ´ ᲼PV - PV 桌 + ᲼ PV - PV 桌   ҈� ҈ PV = PV + PV =    PV  W = = 쟼 �ᆠ� ᆠ泐 h = ҈ Q� ҈ PV    h奠 = 

 » ҈黨 ҈

W ␔ᨨ├ ᨨ  = 矄ᨨ SQ Q҈ + Q + Q + Q = �  = Q҈ + Q Q҈㦨҈黨҈�Q㦨 Q㦨҈� ҈黨҈� -  + ҈� + Q \ = � ҈黨҈� + ҈�

ᆠ㡰 쟼 �ᆠ� ᆠ泐 h =

�



Þ ҈黨҈� -  + ҈� + Q = ҈ Þ Q = ҈ -  Þ Q = -Q = -黨  Þ Q = 黨  㡰 ᨨ ᆠ ᨨ  ��ᨨ Q҈  Q 쟼 �ᆠ� ᆠ泐 = Q҈ ␔  Q҈ 㦨  ᨨ矄 ᨨ鼀矄ᨨᨨ盐 � � Q 㦨  矄ᨨ  ᨨ鼀矄ᨨ�  ᨨ犨 鼀盐 Q  Q w 꾀矄ᨨ ҈ = Q҈ Q҈ ҈ 犨 Þ = ҈ 턼҈ Þ Q҈㦨w맔҈㦨҈J 和ᨨ턼҈Q㦨w Þ Q㦨Q҈w Þ҈҈㦨Q㦨黨J b㡰 QH㦨 ├ 泐 �矄 ��  QL㦨  ᆠ  泐 �矄  ��  Q2 㦨  ᆠ  泐矄ᆠᨨ   ��  ␔ᨨ├ ᨨ 泐 ҈矄  ��  㦨犨ᨨ├ ᨨ  泐   ��  W㦨QHQL㦨QLQ ÞQL㦨QH졔Q q q = H +  qL qL   鼀盐ᨨ ᆠᨨ 矄ᨨ�ᨨ  �矄  �� 

  �  ᆠ ᨨ  ��  QH T҈ Q T =  L = QL T Q T T T Þ = ҈ +  盐矄� � �㡰 T T T +T Þ T = T҈ + T Þ T = ҈   T b㡰 矄� �n㦨 ҈ T҈ T ҈ n㦨 㦨 ҈ T҈  T -  T   = ҈  T҈ 졠  矄ᨨ� � 犨 � T҈㦨黨黨 ᔴ T㦨䰘 ᔴ b㡰 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ  h҈㦨 h㦨 h



\҈  = ҈  = ҈ 

҈



 ᲼Q  �� 矄  ⼄盐泐 �ᆠ� 桌



Þ = = 

҈   Þ  = ҈ 

 �㡰

 =  

 ��㡰

ᨨ鼀 �㡰  ��㡰

 = ҈  㡰

҈



 ҈

㦨 ҈  㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-130

䰘

Physics

҈   犨 꾀 =

 턼҈

   ␔ =   h =

 턼 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  ␔꾀㦨␔

㡰 h꾀 =

҈

턼 -  ҈ \ ҈= ҈´  = 턼   ҈ -  

\  =

 +  

ᨨ h =

 +  㦨�⧤  㡰 ෌�  鼀盐 ᨨ  ᆠᨨ  ᨨ 泐   㦨 � ⧤ 鼀盐ᨨ  ᨨᨨ 泐錐 ҈㦨 ⧤ ᆠ� Q㦨�ᆠ犨ᨨ├ ᨨ ␔㦨䁸 =



쟼 �ᆠ� ᆠ泐㦨 ҈ 

黨

҈

㡰 D㦨鼀㦨�맔맔҈㦨턼矄� ├

턼矄� ├

㦨 矄� ├ 턼矄ᨨ盐ᆠ 矄ᨨ盐ᆠ

҈ -  ´ ҈奠 ҈

h = 奠 ᨨ犨 ᨨ ᆠ ᨨ ᆠ泐ᆠ

 ´  ҈ 㦨⧤ 㦨䰘

 =

҈

\  = -°ᔴ b㡰 �矄 ᆠ  ᨨ鼀 矄ᨨ盐ᆠ�  꾀 꾀�矄

DQ =

 æ PV ö � æ  PV ö R + R  çè R ÷ø  çè R ÷ø

æ ҈ö  � PV +  PV  = ç ÷ PV è ø   ҈ ᆠ㡰 ᔴᨨ �  꾀 ᔴᨨ �   㝐矄矄ᨨ �矄㦨mA 㝐矄矄ᨨ �矄㦨mB ᔴ  ��  矄矄盐㦨 DP ᔴ  �� 矄矄盐㦨҈�DP Þ

PAV㦨

mA RT M

PἘA 㡰㦨

矄ᨨ盐ᆠ ´ 턼矄� ├

矄� ├

쟼 �泐 ᆠᨨ 矄盐鼀  泐  

Þ PAPἘA㦨 Þ D㦨

෌�  矄ᨨ盐ᆠ 㦨 䰘 ᔴ 졔 䰘 㦨 ⧤

 PBP'B 㦨

 æ 

ö - ҈÷ = ҈䰘 ´ ҈�  ␔ᨨ盐盐㦨 � ´  ´҈ ç è 䰘 ø ҈҈ 㡰   ᨨ泐 ᆠ  � ᨨ   ᨨ 泐 �   犨ᨨ ᆠ矄矄 �矄 矄鼀 矄  ᨨ泐 �矄  矄 盐 ᆠ�ᨨ 

PBV㦨

mA RT M

æ 矄ᨨ盐ᆠ ö - ҈÷ \ 犨 ᨨ盐盐 㦨 턼矄ᨨ盐ᆠ 㜠 턼矄� ├  = 턼矄� ├ ç è 矄� ├ ø

矄� ├ 㦨  ᔴ 졔 䰘 㦨 䰘 ├

턼   = 턼҈ ҈

 =  ҈ 

T W W � = = Þ ҈  T҈ Q + W  Q + W

Q � ´  J 㦨 = ␔㦨 � � b㡰 ␔ᨨ├㜠 ᨨ  ␔㡰㦨  꾀ᆠᆠᨨ � � ᨨ � ᆠ� ᨨ ᆠᨨ�鼀泐 �� 㦨턼꾀㦨턼ᔴ 㦨 ᔴ 꾀졔 ᔴ ᔴ  � =  - 꾀 㡰 + ᔴ -  㡰    � =   -   㡰 +   -  㡰   ҈ =    ␔ 

鼀  �ᆠ� ᆠ泐ᨨ  ��  h㡰 = = = ҈� 턼 �� ҈

\ 턼矄ᨨ盐ᆠ =

b㡰 ෌�  턼҈㦨҈ 턼㦨

҈㦨҈䰘 ᔴ㦨⧤

㦨䁸 h㦨䁸 쟼 �ᆠ� ᆠ泐ᨨ ᆠ ᨨ  ��  ␔ h= ´҈奠 턼҈ 턼 - 턼҈ ´҈奠 ᨨ h = 턼҈

P'B V㡰㦨

mB RT M

m A RT m A RT MV M V 㡰

m A RT  MV

 �㡰

mB RT mB RT MV M V 㡰

mB RT  MV �� � �⼄ ��㡰泐 �㡰 ҈�D㦨

mB RT M

 ��㡰

WWW.JEEBOOKS.IN

PS-131

Thermodynamics

҈�

 m ҈�DP mB Þ  = B  Þ mA㦨mB =  mA DP MA 䰘黨҈㡰 ෌�  矄ᨨ Q㦨mL㦨맔҈㦨ᔴ

鼀盐ᨨ �ᆠT㦨䰘⧤

鼀盐 ᨨ  矄盐ᨨ盐 � � T҈㦨䰘졔䰘㦨⧤ 쟼 �ᆠ� ᆠ泐㦨

҈

Þ p㦨

w Q҈ - Q T҈ - T  - 䰘 = = 㦨 Q Q T 䰘

T W = T҈ Q҈

 ҈ Þ ҈ = 黨 Q҈ Þ

҈䰘

 ҈ = Þ Q҈ = ҈  Q҈

 ᨨ   �泐 �  泐   ��  ᨨ   ᨨ犨 鼀盐矄ᨨ�턼㦨턼҈␔㦨҈҈㦨J 㡰꾀矄 ᆠ泐� �矄ᨨ �矄ᨨᨨ鼀  矄矄鼀 ᨨ  �矄 ᨨ  ᆠ   矄矄盐 � 矄�    ᆠ泐�  �矄 鼀ᨨ矄  �ᆠ 矄矄盐    ᨨ盐� ᨨ盐   矄ᨨ犨 盐� � ᨨᆠ矄矄





+ P

P ´ L p é P ´ pR  ù P = ´ L = ê   ú ´ L é Mg ù êë P pR - Mg úû P  ê  ú pR  û ë

P맔 맔p 㡰㦨px맔pRÞ x =

Q҈ -  䰘 = Þ Q҈ = 䰘黨҈ ᔴ  䰘 㡰 ෌� 錐T҈㦨黨KT㦨KW㦨҈J 矄� � ҈ 

- Mg

 pR  0 和� ᆠ   ᆠ泐�  �矄ᨨ 鼀泐ᆠᨨ 盐ᆠ� � \鼀盐 T 㦨 ᆠᨨ 矄  꾀泐� �P҈V҈㦨 PV

Þ

҈

㡰  x   �矄 ᆠᨨ  �矄ᨨ  ᨨ鼀  ᨨ 和 꾀⼄盐���盐鼀 Mg㦨 Pp㡰pR 

҈黨

ᆠ㡰 꾀⼄盐���盐鼀p㦨 P Þ p㦨P졔 LH㡰r�

 �㡰

꾀矄ᨨP맔 pRL㡰㦨p᲼p  LH㡰桌

 (Q PV ҈ ҈ = PV )

L P  L - H 和盐矄�盐� �  �矄 盐 ᨨ  E  ᨨ鼀 �㡰  ��㡰 P L P = P + L - H 㡰 r g P L - H Þ LP㦨P LH㡰졔 LH㡰r g Þ r� LH㡰졔P LH㡰LP㦨 Þ p㦨

P

p H

WWW.JEEBOOKS.IN

EBD_8341 PS-132

Physics

Kinetic Theory

12

Topic-1 : Kinetic Theory of an Ideal Gas and Gas Laws ҈

䰘

㡰 ᔴ泐 ᨨ鼀 ��盐 꾀㦨 ҈꾀졔鼀�

× 꾀

ᨨ 꾀l 㦨 

l҈



l 



Þ

PAV㦨

× 꾀 + 鼀� 꾀l҈





҈꾀 꾀

鼀�

æ ҈ ҈ö

ç  ÷ 㦨鼀� è l  l҈ ø



\鼀㦨 � ç l × l ÷ è ҈  ø b㡰 ෌�  鼀盐T�㦨҈䰘졔䰘㦨黨K

鼀盐Tf 㦨䰘졔䰘㦨K 꾀鼀ᨨ矄 �ᆠ矄矄盐P㦨҈맔҈�Pa ᨨ盐鼀ᨨ ᨨᨨ鼀V㦨m �  ᆠ�  盐鼀ᨨ 鼀ᨨᆠ盐矄nfn�㦨䁸 矄� �� �矄⼄盐�ᨨ PV㦨nRT N㡰 㦨꾀ᨨ� ᨨἘ矄 盐鼀

n=

\

nf  n�㦨

� 

PV æ ҈ ҈ ö - ÷  ç R è T f T� ø 

҈´ ҈� ´  ҈ ö æ ҈ ´  ´ ҈  ç 㦨 ÷ ҈ è  黨 ø � 㦨�맔҈ ᆠ㡰 ᨨ鼀㜠� 

µ 

PV  㡰 RT

Þ

҈   㦨ᆠᨨ 矄  矄矄盐�矄� ᆠ矄� � ᨨ鼀ᨨ҈ 

矄ᨨᨨ�ᨨ  ᆠ㡰 矄 矄 ᆠᨨᆠ 㜠 �  㡰 ҈㝐҈㦨҈  㝐㦨

 㝐  \ ҈´ ҈ = ҈  㝐  

҈    ҈ = ´ =  \  黨    㡰 꾀�矄 矄矄 � �矄ᨨ犨矄矄盐  �� 鼀盐 㡰 꾀ᆠᆠᨨ � �ᨨᨨ泐Ἐ矄犨 PV 㦨 ᆠᨨ 矄  \ PdV 졔 VdP 㦨 Þ

mA RT  M

ᔴᨨ �   㝐矄矄ᨨ �矄㦨mB ᔴ  �� 矄矄盐㦨҈�DP PBV㦨

mB RT M

mA mB RT RT P'B V㡰㦨 M M mA RT mA RT Þ PAPἘA㦨 MV M V 㡰 m A RT Þ D㦨  �㡰  MV mB RT mB RT  PBP'B 㦨 MV M V 㡰 ҈�D㦨  ��㡰 mB RT  MV �� � �⼄ ��㡰泐 �㡰  m ҈�DP mB Þ  = B  Þ mA㦨mB =  mA MA DP ᨨ 盐矄㡰⏌ ᔼ ��泐 ��ᨨ  �矄     �矄 ᆠᨨ 鼀 ᨨ鼀  ᨨ

鼀盐 㦨 ⧤ ҈ 鼀 㦨꾀 㦨

꾀㦨҈ 맔 ᨨᨨ 㡰  �矄ᨨ  矄 � 矄 泐 맔 鼀    � 鼀盐�矄  

꾀  㡰㦨҈

҈





\  꾀 = =   ҈꾀 =  - ҈  - 㡰 ҈  + 㡰 PἘA 㡰㦨

æ l҈  l  ö



ᆠ㡰 ᔴᨨ � 꾀 㝐矄矄ᨨ �矄㦨mA ᔴ  �� 矄矄盐㦨DP

PdV æ ҈ ö æ dV ö æ ҈ ö Þ b맔P㦨҈ = -V 錐 b = - ç ÷ ç = è V ø è dP ÷ø çè P ÷ø dP

 ᆠ� 犨 b P犨�ᆠ �盐 泐ᨨ



� 泐  꾀 - ҈꾀 = 鼀� =  =

Þ



æ ҈ ҈ ö ç ÷ è ҈  -  + ø

æ  ö =  ҈ çè ҈ -  ÷ø

ᔴ맔졔鼀� 㦨ᔴ

    Þ ´ ´  +  = ´

 ҈ ҈  æ 黨 ö æ ö Þç +  ÷ =  ç ÷ ҈ è ø è ҈ ø

 ö æ  ö æ æ   ö

Þ ç  + =  Þç + ÷ = ÷  ø çè ҈ -  ÷ø  ø ҈ è è ҈ ö æ  ö æ Þ  ç  + ÷ç =   ø è ҈ -  ÷ø è 黨 + 㡰  㡰 Þ =҈  ҈ -  㡰 Þ ҈ 졔 㦨 Þ � 졔҈ 㦨 \ 㦨҈䰘»   ᆠ �矄 ᆠ ᨨ鼀ᨨ犨  ᆠ  ⼄盐���盐鼀㦨졔㦨鼀

WWW.JEEBOOKS.IN

PS-133

Kinetic Theory 黨

�㡰矄� �� �矄⼄盐�ᨨ  PV = nRT

Þ PV ҈ ҈ = nR ´ �

P V҈ =

�n R ´  



᲼Q T҈ = � ⧤桌

 �㡰

᲼Q T =  ⧤桌

 ��㡰

�� � �⼄ �㡰泐 ��㡰

 ´ � P҈ P ҈ = Þ ҈ = P �  P � ´  ҈

\

P = � P҈



RT kT = ҈҈ ´ ҈ ᨨ = ҈҈ ´ ҈ M m 꾀矄 鼀盐 �矄 ᆠᨨ 矄 㡰

DP V  �㡰 P ᔼ 矄ᆠᨨ ᆠ矄盐矄� �� �矄⼄盐�ᨨ ��

�

P DV = -nR DT nR DT P 쟼⼄盐� � �㡰  ��㡰犨� DV = -

 ��㡰 

ᔴᨨ鼀� � ᨨ⼄盐�ᨨ 犨�   DT  = C  DP  犨 

 � 鼀ᨨ ᨨᨨ鼀�ᆠ  㡰 =  +  - 㡰

  ҈ � = + 

  ᨨ犨ᆠ  �� ᨨ├� �ᆠ �泐ᨨ  �矄

 T 㡰 PV㦨nRT ᔼ �矄⼄盐�ᨨ 㡰

nRT V

෌� VP㦨ᆠᨨ 矄 ᨨ鼀 �㡰  ��㡰

T = ᆠᨨ 矄  ᨨ T µ v V Q V҈㦨V T҈㦨T V V T҈ T = T Þ T㦨T҈  = T \ = V҈ V V҈ V ҈ 矄㡰 ᨨ�ᆠ盐鼀盐TV µ P ᨨ盐鼀�矄� ᨨ矄矄盐P҈ \ p҈p

 �㡰  ��㡰

D = 턼 =

\

҈

Topic-2 : Speed of Gas, Pressure and Kinetic Energy ҈



 kT =  ´ ҈ -҈  P㦨ᆠ鼀ᨨ �V㦨ᆠ鼀 PV PrgV  ´ ҈ ´ 黨 ´  N= = ;  ´ ҈҈  KT KT ´ ҈ -҈  RT ᆠ㡰 Vrms = M v҈ T҈ 䰘 + ҈䰘㡰    = = = = = � � v T 䰘 + 䰘㡰 �

䰘

� � v҈ = ´  = ҈ � 鼀⏌矄  

҈





ᆠ㡰 矄矄盐 P 㦨

҈ mN  Vrms  V

mN 㡰T V ᔼ    �矄 鼀矄矄   鼀盐  ᆠᨨ 矄   

P µ  V鼀矄㡰 µ  T 和ᨨ ᨨᆠ µ  V鼀矄㡰 µ  T � 盐 ᨨ  q 㦨 ҈ ᨨ



P=

㡰 Q ᔴ =





 ´ ҈ ´  㝐  ´ ҈ ´  »  ´ ҈ - ├� 㝐= ҈黨 ´ ҈黨

�矄�矄

(҈黨 ) =

㡰 ෌� ⧤쟼鼀 㦨

\ v =

鼀矄 (  ) 㝐 꾀  鼀矄 ( 꾀 ) 㦨 㝐  㦨  㦨҈ 㡰 쟼 �泐矄矄ᨨᆠ� 犨�  鼀ᨨ矄ᨨ  �ᨨ鼀�ᆠ�矄

 =



ᨨ  �泐犨    鼀ᨨ矄 ᨨ  �ᨨ鼀�ᆠ �矄 ᆠᨨ   � ᨨ

DT  ⧤ V = = = ҈� ⧤⏌鼀 nR DP  鼀

Þ P㦨

\ T㦨҈ ⧤

� � = 

 쟼 �泐矄矄ᨨᆠ� 犨�  鼀ᨨ矄ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ�矄

DP nR DT V =V Þ DT = DP nR P P

҈҈

 ´ ҈ ´ ҈- T

= ҈҈ ´ ҈  ´ ҈- ҈鼀矄 㝐 㡰 矄� � 鼀矄 㦨 㝐҈ ᨨ

DV = -

C=

҈ ´  ´ ҈  ´ ҈ =  N ⏌ m ҈ ´҈ ᆠ㡰 v鼀矄㦨ve =

҈�㡰ᔼ  �矄ᆠ矄 ᨨ鼀� �矄⼄盐�ᨨ

PV = nRT

P D V + V DP = 

ᨨ盐 矄㡰 ᨨ ᆠ  �ᨨ 鼀ᨨ鼀 盐鼀 盐� �ᆠᨨ�矄�ᨨ

mv   mv 㡰 mv N 㦨 = Dt Dt N ´ mv 㡰 矄ᨨ 矄矄盐 P = Dt ´ A

r 鼀矄矄ᨨ  �矄

黨

ᆠ㡰

鼀矄 =

҈



矄� �V鼀矄㦨

v鼀矄 �盐鼀㡰 v鼀矄 �ᨨ 㡰

=

RT ҈ Þ Vrms µ M M

M �ᨨ

M �盐鼀

㦨

 = ҈ » ҈ 

WWW.JEEBOOKS.IN

EBD_8341 PS-134

҈҈

ᆠ㡰

Physics ᨨᆠ�泐ᨨ 矄ᨨ盐 � �矄 v =

 

 ҈

҈

҈

=

g   㝐  g  㝐  

gp = p

 VP  꾀 �├� �ᆠ �泐ᨨ �矄ᨨ盐矄鼀ᨨᆠ盐矄 ҈  ҈ æ ö  E 㦨 mvrms = m ç v p ÷ = mv p   è ø 

 䰘 ⏌�´  = � ⏌  ´  �

=

b㡰 ␔     ᆠᨨ矄  �矄 �矄 ᆠᆠ  �    ᨨ矄�� 㜠 �ᆠ�ᨨ       矄矄盐 ᨨ    �矄 ᆠ矄矄 ᨨ �   ᨨ矄�� 㜠 �矄   ᨨᨨ犨矄   ⼄盐�ᨨ

DP㦨ra dx 和ᨨ鼀ᨨ矄矄盐ᨨ  矄�  矄矄矄矄盐ᨨ   ᨨ  矄� 



ᆠ㡰 ᨨ鼀㦨 Þ㦨 ᨨ µ

 Q   矄鼀㡰

 ᨨ�  �矄 ᨨ盐 矄矄盐矄ᨨᆠᨨ鼀矄犨ᨨ�鼀矄�  ҈ Vrms 㡰҈ V T = = ҈ Þ b㡰 Vrms 㡰   T Vrms 㡰

Þ

ᨨ鼀 矄  矄矄�ᨨ 矄犨ᆠ  ᆠᨨ ᆠ盐   vp v vrms

gRT M

҈ =  Þ V鼀矄㡰㦨V Vrms 㡰  

꾀矄ᨨ鼀矄㦨

Topic-3 : Degree of Freedom, Specific Heat Capacity, and Mean Free Path ҈

ᆠ㡰 ᨨ �ᨨ   ᨨ鼀f㦨졔㦨� nfRT � RT

ᨨ �泐 U = =   Cp   䰘 꾀  g = = ҈+ = ҈+ = � � Cv f



b㡰 㝐    l =

V

҈�

b㡰 꾀ᆠᆠᨨ � �ᨨ㝐 犨Ἐ矄 �矄�盐�ᨨ ᨨ 矄 �矄

҈

ᨨ 鼀ᨨᆠ盐矄ᨨ  � �矄µ  \ ᨨᆠ�泐ᨨ ᨨ 泐� 鼀ᨨᆠ盐矄犨�矄鼀� 꾀矄犨 矄ᔴ矄 鼀盐ᨨ A C矄鼀 ҈㡰 ᨨᨨ鼀鼀 矄⼄盐矄 �矄�� 泐

RT M M㦨㝐ᨨ鼀矄矄ᨨ �矄鼀ᨨᆠ盐 T㦨鼀盐ᨨ  �矄鼀ᨨᆠ盐 vrms =

盐 v鼀矄 = 

␔ ��  v = v  

\ ҈䰘

҈

RT 㝐 

=

RT M 

Þ



҈



=

�䰘 Þ T = ҈ ⧤ 

矄㡰␔ ├ ᨨ犨  鼀矄矄 R T 㡰 RT v㦨 \ vἘ㦨v   vἘ㦨 M M ⏌ g ҈RT CH  㡰҈ M҈ g҈ M  = = ´ 矄㡰 C M҈ g H e 㡰 g  RT  M

䰘⏌�  䰘   ´ = ´ ´ = �⏌  � � � 矄㡰 ᨨ �ᆠ盐 鼀盐 ᨨᨨ 鼀  矄⼄盐 矄  ҈ Vrmsµ M �Vrms犨�  �  盐矄 ᨨ �  �矄矄



㝐 �鼀矄  矄ᨨ 鼀盐 鼀ᨨ鼀矄矄   ᆠ鼀矄 矄 犨� �   ᨨ �  � �矄矄 ᆠ 㡰 ␔├ ᨨ犨  

矄㡰 㝐和矄 鼀矄 =

v=

 RT 錐 vrms = pM

kT R

\t =

l ҈ Þtµ T kT m

ᆠ㡰 꾀矄 犨 ├ ᨨ犨 Cp  g= = ҈ + 犨 f㦨 �ᨨ   ᨨ鼀 Cv f 꾀㡰 㝐ᨨ ᨨ鼀�ᆠf㦨

 � =   㡰 �ᨨ鼀�ᆠ��� 鼀ᨨᆠ盐矄f㦨�  䰘 \ g = ҈+ = � � ᔴ㡰 �ᨨ鼀�ᆠ ᨨ 㜠��� 鼀ᨨᆠ盐矄f㦨䰘  黨 \ g = ҈+ = 䰘 䰘 㡰 �ᨨ鼀�ᆠ��� 鼀ᨨᆠ盐矄f㦨   \ g = ҈+ =   㡰  �ᨨ   ᨨ鼀f㦨졔㦨 ᨨ�ᨨ鼀�ᆠ ᨨ 㜠�  鼀ᨨᆠ盐 ᔼ   �泐ᨨ 鼀ᨨᨨ  �矄鼀盐T \ g = ҈+

T



㦨

҈黨

҈

pnd  犨 d㦨 �鼀ᨨ  鼀ᨨᆠ盐 n㦨 盐鼀ᨨ 鼀ᨨᆠ盐矄盐 �ᨨ盐鼀 l 盐鼀 �鼀ᨨ ᆠᨨ�矄�ᨨ  t = v鼀矄

 RT RT  vp 㦨 M M

f  nRT = RT = RT   b㡰  Cp   Cv     矄ᆠ� �ᆠ  ᆠᆠ�泐 ᨨ    �矄  ᆠᨨ 矄  矄矄盐   ᨨ盐鼀 꾀 ᆠᨨ 矄  矄矄盐  ⼄盐�

U =

�

DQ҈ = nC p DT Þ ҈ = nC p × �

 �㡰

꾀 ᆠᨨ 矄  ᨨ盐鼀  ⼄盐�

DQ = nCv DT Þ  = nCv ×҈

 ��㡰

�� � � �㡰泐 ��㡰犨� Cp  ҈ C p � = × Þ =  Cv ҈ Cv 

WWW.JEEBOOKS.IN

PS-135

Kinetic Theory g=

Cp

Cv

=

  =҈+  f

 ᆠ �  犨  t ⏌矄

f㦨 �ᨨ   ᨨ鼀㡰

Þ f =  

䰘

҈҈

㡰 ᨨ �泐ᨨ  �矄鼀� 盐 f҈n҈ RT҈ f  n RT + E鼀�  =   � � =  ´ RT + ´ RT = ҈�RT   㡰 꾀矄犨├ ᨨ犨鼀  

 � R   CP҈ = R   � 䰘 CP = R ᨨᨨ 泐�  CV = R     � 䰘 n R + n R N҈CP҈ + N C P   = ҈黨 nR ´  g= Þ g =  �  ҈nR㡰 N҈CV҈ + N CV n R + n R   æC ö ҈黨 \ç P ÷ = C è V øm�xture ҈

҈ N æ ö  ç ÷ pd  èV ø  N㦨 ᨨᨨ 鼀ᨨᆠ盐 V㦨ᨨ盐鼀ᨨ ᆠᨨ �  d㦨 �鼀ᨨ 鼀ᨨᆠ盐 盐 PV = nRT = nNKT

҈

N P ҈ KT = =n Þ l= V KT  pd  P ᨨᆠᨨ 矄 ᨨ盐鼀   ᆠᆠᨨ 矄  盐鼀  矄�泐n ᨨ �矄 P 鼀ᨨᆠ盐矄 �矄 ᆠᨨ 矄  T 和ᨨ鼀   鼀� 矄矄鼀 꾀矄鼀盐� ᆠ矄矄 ᨨᨨ ᆠᨨ�矄�ᨨ � ᆠ矄矄矄ᨨ �ᨨ

�鼀 ᆠ矄矄 㡰 和ᆠ� �ᆠ  ᨨ �矄 ᆠᨨ 矄  ᨨ盐鼀 ҈ Cv = fR錐 f =  �ᨨ   ᨨ鼀  ᨨ�矄꾀 �ᨨ鼀�ᆠ㡰 㦨�  矄�ᨨ 졔ᨨ�ᨨ 㡰

黨

ᨨ�矄 �ᨨ鼀�ᆠ㡰�  ��ᨨ ᨨ  矄�ᨨ 졔ᨨ�ᨨ 㡰 ��ᨨ  �ᨨ   ᨨ鼀 � CvA  R � 䰘 B \ Cv = R  ᆠ = =  CvB 䰘 R 䰘  ᨨ 盐矄㡰㝐   ᨨ �矄鼀ᨨᆠ盐�矄�� 泐

҈

҈

҈�

p d  n n㦨 盐鼀 ᨨ  ᆠᨨ�矄�ᨨ 矄 盐 � ᨨ盐鼀 d㦨 �鼀ᨨ  鼀ᨨᆠ盐 ᔼ �矄 ᨨ 鼀ᨨᆠ盐�矄 

\ tµ

҈ pnd  v

=

҈ pnd  M҈

M RT

d M \ t҈ = ´   t M d҈ d

æ ççQ v = è

҈

 æ ҈ ö ´ç ÷ = ҈黨 ҈ è 䰘 ø

ᆠ㡰  �ᨨ �鼀 t㡰 µ   v µ T

\tµ

҈ T

RT M

ö ÷÷ ø





n҈᲼Cv҈ 桌 + n ᲼Cv 桌 n҈ + n

R �R ù é ê ´  + ´  ú 㦨 ê ú + ê ú ë û 㦨҈ 㦨҈맔㦨҈䰘⏌鼀ᨨ├ � Cv ҈ ҈ = = b㡰 F㦨 㦨 C p r 䰘 ⏌ �㡰 䰘 䰘 䰘 ´ ҈ �  W = ҈- = ᨨ Q㦨 W = 㦨�   䰘 䰘 Q ᆠ㡰 㦨�맔҈鼀 㦨҈鼀ᨨᨨ 졠

㦨⧤ 鼀矄㦨鼀⏌矄 ҈ \ l= p 

҈

҈ = = p    t l

 ´  ´  ´ ҈

p ´ ҈ -҈ ´ 黨 � ´ ҈ -

ᆠᨨ矄矄盐�  �� ᨨ�ᨨ �矄㦨҈҈ ᆠ㡰 꾀鼀ᨨ盐  ᨨ   ⼄盐�  턼㡰 ᨨ �矄   鼀盐  ᆠᨨ 矄  ᨨ盐鼀 턼㦨 ᔴD

 �㡰 꾀鼀ᨨ盐  ᨨ   ⼄盐�  턼҈㡰  ᆠᨨ 矄  矄矄盐 턼҈㦨 ᔴD

 ��㡰 =



=

ᆠ㡰 ᲼Cv桌鼀� 㦨

꾀��鼀

l 㝐  �鼀 t = v Þ t=

҈

n҈Cv + nCv

ᨨ

҈

l=

n҈C p + n C p

  � n҈ n n +n + = Þ +  = ҈  Þ  � g m ҈ g ҈  ҈ g   ҈ g m ҈  ҈ ҈   � ҈䰘 黨 ´ � Þ gm = = ҈ Þ g 鼀 ҈= Þ + = ҈ ҈ ҈  gm ҈

� R 

v

㡰 矄� �g鼀� 盐㦨

҈

Þ

\C A =

 �矄  矄��  �  犨 �ᆠ  �矄 T ᆠᨨᆠ泐 �ᆠ  泐�  矄 ᨨ犨  �  ᨨ�ᨨ  ᆠ㡰 㡰 �盐鼀�矄鼀ᨨ ᨨᨨ鼀�ᆠ�矄 졠 泐� �矄 �ᨨ鼀�ᆠ�矄 ᨨ �盐鼀 CV҈ =

l=



҈

�� � �⼄盐�ᨨ  ��㡰泐 �㡰犨�

鼀    ҈ Þ t µ 矄 

æ 䰘ö Þ Q҈ = Q㡰 ç ÷ è �ø

\

Q҈ C p = Q Cv

C p 䰘ö æ çQ g = C = � ÷ è ø v

WWW.JEEBOOKS.IN

EBD_8341 PS-136

҈䰘

Physics

b㡰  g A =   g B =

҈

CP 黨 = = ҈ < ҈  �ᨨ鼀�ᆠ㡰 Cv 



g 鼀� 盐

 ҈ = = ҈ > ҈ ҈ 䰘

b㡰 矄� � t=

\ µ 

҈  p  �

ᨨᨨ 鼀ᨨᆠ盐矄 ù é êë\ = úû ᨨ盐鼀

\盐 =

R  R ᨨ �ᨨ�  M㦨㡰Cp  Cv㦨 b =  a = ҈ ᨨ a㦨҈b \ b





�   㡰 + ´ �

 

ᔴ ᔴ

æ ö 䰘 = ç҈ + ÷ = ᔴ è � ø � 䰘

㡰 ᨨ  ᨨ泐ᨨ�ᆠ ᨨᆠ矄矄

\ ᔴ - ᔴ = ҈-

҈-

\ ҈ - = \ ҈=

ᔴ - ᔴ ᔴ - ᔴ ᔴ = ᔴ +

  ᨨᨨ 㦨҈  ᆠ㡰   矄   Q = nC D 矄�矄� ᆠᨨ矄 矄矄

ᨨ ᨨ盐 鼀矄矄 鼀盐 矄 ᨨ盐 �鼀矄� Ἐ

\ =

㦨 矄鼀矄㦨 RT ⏌ M

҈� � ´ R ´ ´ ( T - T )  

=

䰘 é CP ù êë\ CV = γ d�atᨨm�c = �  C p - Cv = R úû



 =

㡰 ⏌

㦨҈黨 ⧤ � 鼀盐㡰 ᔴ  �� �   �泐 D =

æ  öæ � ö =  ç ÷ç ÷ -҈҈҈㡰 = -䰘 ├ è  øè  ø

D



ᔴ - ᔴ ᔴ - ᔴ

Q ᔴ  - ᔴ  = 㡰

㡰 矄� � ⼄盐���ᨨ  ᨨ   �泐 犨 

C=

� ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄 g = 



ᔴ - ᔴ  - ᔴ - ᔴ  - ᔴ + ᔴ  = ᔴ - ᔴ ᔴ - ᔴ

 KT = mCT 

ᨨ 턼㦨҈㦨҈├ ᆠ㡰 ᔼ     ��ᆠ ᨨᆠ矄矄

g҈ 㦨ᔴᨨ 矄 ᨨ ҈҈g҈ 㦨 g҈

㡰⏌㦨  㡰⏌ Þ

æ ö = g = ç҈ + ÷ è ø

犨  �矄 �ᨨ   ᨨ鼀

æ  ö =   =  =   ( ) ├ ÷   è  ø 꾀   æ鼀ö  æ ö     㦨  ç ÷ =  ç ÷ 㦨 ´ ´҈ ´ = ҈� ´҈   è r ø  èø  



㡰  �ᨨ ᨨ  矄ᆠ� �ᆠ 矄  ᆠᨨ 矄  矄矄盐 ᔴ 㡰  ᆠᨨ 矄  ᨨ盐鼀 ᔴ㡰

ᔴ

㦨҈�

ᆠ㡰 鼀 �泐ᨨ 鼀ᨨᆠ盐

\턼㦨

R M

ᨨ 泐 ᨨ�  M㦨㡰Cp  Cv 㦨 a =

㦨 ç



㡰 꾀矄犨├ ᨨ犨CpCv㦨R犨 Cp Cv鼀ᨨ矄ᆠ� �ᆠ  ᆠᆠ��矄 ᨨ Cp  Cv㦨

㡰  = ҈ ҈ +  



ö  = ÷÷ ø鼀� 

� 䰘 g ҈ =  g  =  矄ᨨ� �犨� 㦨  � �

ᔴᨨ 矄� � �  矄�ᨨ    ᨨ�ᨨ  鼀ᨨ 矄 �矄 ᨨ  ᨨ鼀 ҈㦨�  㦨

g g -҈

 g -҈

盐� � 盐ᨨ  ҈㦨 㦨  ç

҈ �  = ´ » ´҈ ᨨ  ´҈  

҈

ö ÷÷ ø 鼀�

҈g҈ + g -҈ = ҈

҈ + g҈ - ҈

æ ᔴ çᔴ è 



=  =  ´ ҈ 㡰 㡰 = ´  ´ ҈   

ᔴᨨ 矄� � ��矄�矄鼀ᨨ ᨨᨨ鼀�ᆠ� 㦨 쟼 �泐쟼㦨黨맔҈



æ ᔴ = çç è ᔴ

෌矄꾀 矄鼀ᨨ  �㜠 �矄ᨨ   ᨨ鼀 㡰 쟼 �泐ᨨ  �矄쟼

=

҈黨

b㡰 矄� � ᨨ鼀盐

黨 

 ´҈ ´҈  ´  ´҈ 䰘 ´҈

\ ᔴ 㦨 黨� ⏌├�⧤ b㡰 b㡰 졠 ��� �矄鼀鼀ᨨ盐 ᨨ  ᆠᨨ 矄 矄矄盐  �矄 ᨨᆠ  �� 鼀盐 ᨨ鼀ᨨ ᨨ � ᨨ泐ᨨ鼀�ᆠ

æ ᨨᨨ 鼀ᨨᆠ盐矄 ö D턼㡰  = mᔴ  D ç m = è 꾀ᨨ� ᨨ Ἐ矄 ᨨ ÷ø ᨨ

D µ

҈

ᨨᨨ 鼀ᨨᆠ盐矄

WWW.JEEBOOKS.IN

PS-137

Kinetic Theory ҈

҈ U㦨 nfRT  犨 f㦨 盐鼀ᨨ  �矄ᨨ   ᨨ鼀

䰘





䰘㡰犨ᨨ├ ᨨ ᨨ �矄  矄盐� ᨨ �矄 ᨨ T   � ⼄盐���盐鼀鼀盐ᨨ  �矄�  矄矄

ᨨ�   �泐ᨨ �矄矄鼀� 矄鼀

fO = �  fAr㦨 æ� ö æ ö U = U O + UAr =  ç RT ÷ +  ç RT ÷ è ø è ø

\ 



\ ᆠ㡰

ᨨ�   �泐U㦨҈҈

꾀� 矄�ᨨ ├� �ᆠ �泐ᨨ  � �矄鼀ᨨᆠ盐

�矄

 ├ 犨 �ᆠ   矄 ᨨ  鼀盐 ᨨ 泐  ᨨ � 

鼀盐 �矄 矄鼀  矄�ᨨ  ├� �ᆠ  �泐ᨨ  졠   ᨨ 犨�⼄盐 㡰 ᨨ � �矄㦨

ᔴᨨ �ᆠ� ᨨ ᨨ盐鼀  矄�ᨨ

æ D ö = ᔴᨨ 矄  ç ÷ = è D ø  꾀� 矄�ᨨ ⧤쟼 ᨨ졠㦨

� u҈ + u = u Ἐ҈ + u Ἐ ᨨ n҈Cv DT҈ + n Cv DT = n҈ + n 㡰CvT

Þ ҈㡰Cv 㡰 + �㡰Cv 㡰 = ҈�㡰CvT \T = 黨

 ├



 ҈

=

n҈Cv + nCv  ҈

n҈ + n

�

Cp Cv

=

R = ҈� R

T盐㡰 ᔴ泐Cp>CvCpCv㦨R Þ CP = CV 졔 R bᆠ㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  ᨨᨨ 鼀ᨨᨨ  泐 ᨨ� 㦨 ᨨᨨ 鼀ᨨᨨ �盐鼀㦨҈

ᨨ�   �泐盐

Vs 㡰m�x = Vs 㡰 He

㡰 꾀ᆠᆠᨨ � �ᨨ 犨ᨨ ⼄盐���ᨨ ᨨ  �泐 � ├� �ᆠ �泐矄矄ᨨᆠ� 犨� ᆠ  �ᨨ   ᨨ鼀鼀ᨨᆠ盐 �矄

=

҈ ├   ᔼ  �矄 ᆠ矄 졠   ᨨ   犨ᨨ �矄 ᨨ 

g m�x M He ´ M m�x g He

ᨨ�ᨨ ├� �ᆠ �泐 矄� ᆠ 鼀盐�矄矄ᨨ矄鼀

 ´ KT  �.e.҈҈  �ᨨᨨ  �ᨨ�ᨨ ├� �ᆠ �泐  ´ KT  

㡰 �矄ᨨ A�矄 ᨨ鼀ᨨ  ᨨ 犨�矄盐�  ᆠᨨ 矄  矄矄盐 \ DQA㦨nCpDTA  �㡰 �矄ᨨ B�矄   �    ᨨ 犨�矄盐� ᆠᨨ 矄  ᨨ盐鼀 \ DQB㦨nCvDTB  ��㡰 盐 DQA㦨DQB �� 㡰 \

nCpDTA㦨nCvDTB

DTB 㦨g DTA㡰 㦨 ҈㡰 ⧤㡰 \ DTB㦨⧤

æ Cp ö ÷ DTA è Cv ø

\DTB㦨 ç

᲼g㦨҈ �ᨨ鼀�ᆠ㡰桌

 � R + ҈´ R   = R ҈+҈

 ҈ ҈ n҈ + n n n = + = ҈ +  Þ 䰘 g 鼀� - ҈ � g 鼀� x ҈ g҈ - ҈ g   ҈ -҈ -҈  �  ҈   � = + 㦨 Þ g 鼀� - ҈ = \ g 鼀� =   g 鼀� - ҈  

æ ö æ �ö ҈㡰 ç R÷ + ҈㡰 ç ÷ R è ø è ø = = R ҈+ ҈

Cp ᨨ  鼀� 盐㡰㦨Cv 졔 R 㦨 R

\ g 鼀� 盐 =

n҈ + n

҈´

f҈ f  � nRT +  nRT Þ u = RT + RT =  RT    d u  RT \꾀��   �泐鼀ᨨ㦨 㦨 㦨RT n  gRT ␔├ ᨨ犨 V矄ᨨ盐 㦨 M

g҈ =

Cv ᨨ  鼀� 盐㡰

n҈Cv҈ + n CV

=

�  鼀 矄�矄�矄鼀ᨨ ᨨᨨ鼀�ᆠᨨ Cr = R ҈   䰘 � g  = 鼀 矄�矄�矄 �ᨨ鼀�ᆠᨨ Cv = R  � 

b㡰

 = 䰘 ⧤ 

㝐ᨨ矄ᆠ� �ᆠ ᨨ   鼀� 盐ᆠᨨ 矄 ᨨ盐鼀

Cv =

 �矄ᨨ   ᨨ鼀 ᨨ 矄�ᨨ 鼀ᨨ�ᨨ 㡰 ᨨ犨 ᆠ矄� 矄矄盐 � ᆠ矄矄 ᨨ盐鼀 ᔼ� ᆠ矄矄鼀   ᨨ  鼀ᨨᆠ盐矄꾀矄ᨨ�⧤쟼 ᨨ矄 ᨨ  ᨨ  �矄矄ᨨ鼀ᨨᆠ盐矄ᨨ ᆠ ᆠᨨ鼀ᨨ  ᨨ 鼀� 盐ᨨ �矄矄 矄鼀� 矄�ᨨ  �泐 

҈ � DU nCv DT Cv ҈ = = = = = Q p nC p DT C p g 䰘 ⏌ � 䰘

㡰 �   �泐ᨨ  鼀ᨨ矄ᨨ  � �矄

␔├ ᨨ犨 Vrms㦨

Vrms 㡰 He = rms 㡰 H 

\ V 

 ´  =  = � � ´  ҈ ´  + ҈´  é ù = ú êëQ M m�x =  û

RT M

M H M HE

=

 ҈ =  

b 㡰 ␔├ ᨨ犨  ᨨ�矄矄CpCv㦨R

� �  R 錐 C p = R 錐 g =    ҈� \ C p Cv =   C p + Cv =   � 䰘 䰘 ᨨ �ᨨ鼀�ᆠ�矄 Cv = R 錐 C p = R 錐 g =   � � + =  C C \ C p Cv =   p v 

ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄 Cv =

WWW.JEEBOOKS.IN

EBD_8341 PS-138



Physics

b㡰  ᨨ 矄�ᨨ ├� �ᆠ  �泐ᨨ   鼀ᨨ矄 ᨨ  �矄 㦨



҈� 

æ ҈  ö ÷和 꾀 ø è 꾀

㦨D꾀㦨 ç

Q PV㦨 㡰

㦨 ҈ 㡰├ 和㦨D ├ 和

Ӹ矄 鼀ᨨᆠ盐矄ᨨ �矄ᆠᨨ� 犨� ᆠ ᨨ   ᨨᆠ��矄 ᨨ  鼀ᨨᆠ盐矄ᆠ  � 盐ᨨᆠᨨ�矄�ᨨ 

æ ö = ⧤  ᨨ 鼀

ᆠᨨ 矄 㡰 ÷ çQ è 꾀 ø

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈

㦨 



 ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ

㡰   �矄矄盐� ᆠᨨ 矄  矄矄盐�.e. ᨨᆠ矄矄 �矄 �矄ᨨ�ᆠ \Q㦨n CpDt

=

� é� ù êë  R úû ´ Dt 㦨맔  맔҈맔�㦨 � æ ö çQ C p =  R ᨨ 鼀ᨨ ᨨ㜠ᨨ鼀�ᆠ �矄 ÷ è ø

ᆠ㡰

҈和

æ nRT ö \ç T = ᆠᨨ 矄 ᨨT V ҈ = ᆠᨨ 矄  è V ÷ø  \PV㦨nRT㡰 �  �� � ⼄盐�ᨨ 犨�

ᨨ 盐鼀ᨨ 鼀ᨨᆠ盐矄⏌矄ᆠ

T  T T dT  dV =  ᨨ dT = dV  V V V

= ҈和 =

 �㡰

ᨨ鼀   ⼄盐�ᨨ

dV㦨VgdT

g㦨ᆠᨨ �ᆠ� ᨨ ᨨ盐鼀  矄�ᨨ ᨨ �矄㦨

dV V 

 dV = V  T ҈ � DU nCv DT Cv ҈ = = = = = Q p nC p DT C p g 䰘 ⏌ � 䰘

ᨨ鼀⼄ �㡰g㦨 㡰



黨J㡰

䰘

ᨨ   ��ᆠ ᨨᆠ矄矄 TVg҈ 㦨 ᆠᨨ 矄 

æVf ö T Þ � =ç ÷ T f è V� ø

g ҈

æ V ö T Þ � = ç �÷ T f è V� ø � ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄 g =  T� T \T f = = �  �  ҈

(

g ҈

)

ᔴ  �� �   �泐Du㦨nCVDT

 æT  ö æ ö = ҈ ´ R ç �  T� ÷ = ´  ç ÷ ´ ҈ = 黨 J è ø ø  è  �

鼀ᨨ矄ᨨ犨� 盐矄ᨨᨨ矄��ᨨ 犨� ⼄盐矄矄盐 ᨨ � 矄� 矄  ᨨ҈㦨





҈



㦨  㦨 㦨 ҈ 㝐 㝐҈  °  㝐҈   ´  = ҈黨° \ a㦨 = = =  + 䰘㡰 ҈ 㝐   䰘

҈㦨 Þ 

bᆠ㡰 ᨨᆠ㦨矄矄盐맔꾀

҈ =

҈



   = 꾀 꾀



D ҈ 㡰 和 = D D

D ├  和 æ D ö æ ├  ö =ç ÷和 ÷ç b l è l øè b ø

졠�ᨨ  ᆠ㡰 �矄 ᆠᨨᆠ 꾀矄 D  犨� ᆠ矄 犨�  �鼀 矄ᨨ  ᨨ  鼀ᨨᆠ盐矄 �� �  矄   ᨨ盐�   盐 ᆠ矄矄犨�  �鼀  ᆠ ᨨ�ᨨ  㡰 �矄 � ᆠᨨᆠ bᆠ 㡰 㡰 꾀矄犨├ ᨨ犨Q㦨mcDT

Þ

෌� T�㦨҈├Vf㦨V�

ᨨT�V�g҈㦨 TfVf g҈

和

ᨨᆠ ᆠ㦨 矄矄盐맔㦨ᨨ 盐鼀ᨨ 鼀ᨨᆠ盐矄맔 b D ├ 和㦨l ҈和b᲼b㦨�矄ᆠᨨ盐矄 ᨨᆠ �� 㡰桌 Þ ҈bl 㦨D ├

和ᨨ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ

pT㦨ᆠᨨ 矄  �� 㡰



D ├  和 b

dQ dT dQ = mc µ C �ᨨ  矄ᨨ�ᨨ µᔴ ᨨ dt dT dt

ᔼ     �  ᨨ ҈⧤ ᨨ鼀   �  ᔴ � ᆠ矄矄 犨� 鼀盐 盐 ᨨ � 泐  ᨨ    犨 �ᆠ   �矄 矄ᨨ  �矄 犨�  鼀盐 盐 ᨨ � 泐 㡰 꾀矄 盐ᨨ ᔴ�矄��  鼀盐 �㜠 �⧤  矄ᨨ � � ᆠ矄� � 鼀盐 ᨨ鼀㜠 ҈⧤�矄矄矄    ⼄盐�  ᨨ� ᆠ矄� � 鼀盐 ᨨ鼀㜠�⧤ ᆠ㡰 ᨨ鼀 �  盐ᨨ ᔴ ᨨ矄 ᨨᆠ  ��   鼀盐 �㜠�⧤  ᨨ �矄 ᨨᆠ  ��

 ᨨ   矄ᨨ�ᨨ �  �矄 � 㡰 꾀矄   盐ᨨ  ᔴ � ᆠ矄矄 ᨨ鼀 㜠⧤   ᨨ 矄ᨨ�ᨨ � ᆠ矄矄�   �㜠⧤ b 㡰 

㡰



ᨨ 

ᔼ矄ᨨ 鼀 ᨨᆠ矄矄

꾀 

 

 

 �� �㡰

  ᨨ





 �� ��㡰



␔ᨨ├ ᨨ 㦨꾀盐 PVᆠ盐 V㜠 �矄 \W҈>W 㡰 ᨨ 矄盐 泐㜠  ��鼀 ᔼ  �� ᨨᆠ矄矄AB�矄矄�� � ᔼ 矄 ��矄ᨨ   ᨨ矄�� � ᆠ

⼄盐�ᨨ ᨨ � �矄P㦨a졔b  �㡰

WWW.JEEBOOKS.IN

PS-139

Kinetic Theory ␔ a   bᨨ矄��ᆠᨨ 矄 矄

Q PV = nRT nRT nRT \ =  aV + b \P = V V  aV  bV ᨨT㦨 + nR nR

ᨨ  ��㡰

㦨 - ´  ���㡰

�矄矄 矄ᨨ� 鼀矄ᨨ T V \  ABᆠᨨ鼀矄ᨨ ᨨ ᆠ㡰 ᨨP㜠T ��鼀�鼀� �  �㡰  ��㡰

҈҈

҈

nRT \ P = a + b ᨨ P   Pb = anRT P

dV



d T dV  V㦨

黨

=

҈-

é P + H rl g ù \ T = T ê ú ë P + H - y 㡰rl g û

 㡰

-  ´

a a += nR nR



�矄 ��ᔼ鼀 矄T 矄矄ᨨ鼀鼀 �鼀盐鼀盐

҈

b �矄 盐ᨨ 鼀 �鼀ᨨ 鼀盐 a



T ᲼ P + H - y 㡰rl g 桌 � nR ´   V=  ᲼ P + H - y 㡰rl g 桌 ᲼ P + H rl g 桌� nRT = 

\ 盐ᨨ泐 ᆠ泐 ᨨᆠ

DW҈ + DU҈ = DQ҈   DW + DU  = DQ

DQ҈ + DQ = 

 g 桌�

[ P + H rl g ] T҈ T 꾀ᆠᨨ 矄 矄矄盐VµTᨨ = V҈ V T T \ ҈ =   \V㦨A맔h㡰 Ah҈ Ah T h   ´҈ = 鼀 Þ h㦨  ҈ =   T҈ ᲼ P + H - y 㡰rl

҈

\ T㦨��⧤

nRT rl g

= V rl g =

㡰 꾀矄 矄矄盐ᨨ �矄矄� ᨨ ᆠᨨ鼀鼀 矄�矄 矄鼀 \ nC p҈ ( 䰘 - T ) = nC p ( T -  )



᲼ P + H - y 㡰rl g 桌� [ P + H rl g ] �

 䰘 R ( 䰘 - T ) = R (T - )   Þ ҈ - T = 䰘T -  Þ ҈T㦨黨 \ T㦨黨⧤

��T㦨䰘T Þ ҈T㦨 꾀泐� � �矄 犨 ᨨ   鼀ᨨ 泐 鼀�ᆠ矄

é P + H - y 㡰rl g ù � T = T ê  ú ë P + H rl g û b㡰 Q PV㦨nRT nRT nRT Þ V = = P P + H - y 㡰rl g ␔ P�矄矄矄盐ᨨ  盐 �泐ᨨᆠ�ᨨ  �矄  泐 ᨨ鼀   ᨨᨨ鼀 和盐矄�盐� � 盐ᨨ P T ᨨ鼀ᨨ犨�

꾀矄ᨨ PAVA = PBVB  RTA = RTB ᨨr TA = TB ᔼ �ᨨ� � ᨨ鼀꾀ᨨ 鼀盐ᨨ  �矄 �矄� ᆠ矄矄ᨨ 鼀 �鼀盐鼀V㦨b⏌a

  鼀盐 ᆠ矄矄 矄ᨨ ᨨᨨ��� 盐 㡰 T  � 鼀盐ᨨ  �矄矄犨  ⼄盐���盐鼀 �矄ᆠ �  ᨨ矄泐鼀ᨨ ᨨ鼀�ᆠ�矄 ᆠᨨ 矄 ᨨ盐鼀 㦨 ��  泐 �ᨨ鼀�ᆠ�矄ᆠᨨ 矄  矄矄盐

� 䰘 R ( 䰘 - T ) = R (T -  )  

� �⏌ 

é P + H rl g ù  �  = T ê ú ë P + H - y 㡰rl g û

 �㡰

\ nCv҈ ( 䰘 - T ) = nC p (T -  )

҈

 ᨨᨨ犨ᨨ├ ᨨ 㦨҈ 㡰  ᨨᆠ矄 ᆠ� �矄� 矄 盐ᨨ泐 ᆠ泐 ᨨᆠ 犨 �ᆠ  �矄   ᨨᆠ 盐ᨨ矄矄盐ᨨ  �⼄盐�  �㡰 ᨨᆠ ᨨ  ��泐 �ᆠ泐 ᨨ犨 犨 矄㡰 ��㡰�矄ᆠᨨ盐矄 ᨨᆠ �ᆠ泐 ᨨ犨 犨 矄㡰 b㡰 꾀矄 盐 ᨨ矄 ᨨ ᆠ  � 泐 犨�  �⼄盐�  和ᨨ   ᨨᆠ矄矄 �矄  ��ᆠ 꾀泐� � �ᨨ  T g P҈ g = ᆠᨨ 矄 

éP ù g T = T҈ ê ҈ ú ë P û T҈㦨T P҈ = P + H rl g T㦨TP㦨P � P = P + H - y 㡰rl g  g = 

ᨨ鼀 eq ( ��� )  T =

d T

R �R ´ ҈䰘� +  ´ ´҈� 㦨��R졔�R㦨҈R  

҈-g

Pb P + ᨨT㦨  �㡰 a nR a nR

�矄矄 矄ᨨ� 鼀矄ᨨ T P \  ABᆠᨨ鼀矄ᨨ ᨨ 㡰 ��ᨨ ᨨ  ᨨ �AB

 aV  bV + nR nR dT aV b \ = + dV nR nR b dT =  V = ␔   dV a

- ( DW҈ + DW ) = DU҈ + DU 

㦨 nCv҈ ( �� - 䰘 ) + n Cv ( �� -  )

 �

෌矄�矄ᆠᨨ鼀矄矄 犨� ᨨ盐  ᆠ  �和ᨨᨨᆠ矄矄�矄 ��ᆠ ᨨ鼀T҈V҈r҈ 㦨 TVg҈

æ V ö \T '҈㦨T ç ÷ è V҈ ø

g-҈

æö =  ç ÷ èø

⏌�

㦨⧤

WWW.JEEBOOKS.IN

EBD_8341 PS-140

҈�

Physics

␔   ᆠᨨ �  �矄 矄ᨨ  ᨨᆠ�泐 ᆠ矄矄 泐 v

ᆠ㡰

҈   ᆠ├� �ᆠ �泐 ᆠ矄矄泐 MV 

dv ҈ = k T ҈⏌ dT  kdT ᨨ dv = 犨  dT = ҈K  =  ⧤  T dv kdT ҈ ҈ æ dT ö = ´ = ç ÷ ᨨ v  T k T è T ø ҈ dT dv \ ´ ҈ = ´ ҈ v  T ҈ æ ҈ ö ҈ ᨨ奠ᆠ  �� v㦨 ´ ç ÷ ´҈ = = ҈䰘奠  è  ø 

ᨨ

ᆠ矄� ├� �ᆠ �泐㦨ᔼ ᆠ矄� �   �泐ᨨ  �矄

҈  mv 㦨 nCVDT 

mv ҈  m æ ö mv = ç R ÷ DT \ DT =  M è ø R ҈

T鼀盐ᨨ  �矄

 �矄 ᆠ 泐 ᨨ鼀ᨨ �盐鼀� 

҈ 矄��鼀 �



ᨨ ��ᆠᆠ  �PV㦨ᆠᨨ 矄 

犨 犨ᨨ矄盐ᆠᆠ矄矄�ᆠᨨ�矄�ᨨ 矄 㦨l㦨m Q l㦨҈鼀㡰

\ V ( dP ) + P gV g ҈ ( dV ) = 

�矄 ᆠ  = = ҈ 鼀⏌矄 鼀矄㦨 �鼀 ҈⏌ �

ᨨ 1m

㡰

Q ᔴᨨ鼀矄矄���泐 ( C ) =

҈ \ DC = C  C҈ gP ҈ ҈ ҈æ ҈ ҈ö ᨨ DC =  = ç  ÷ gP gP҈ g è P P҈ ø

 ├

   - ´ ҈ ⧤쟼㦨 ├ = ´ ҈ ´ ҈  

(

)

㦨҈맔҈҈

ᆠ㡰

ᨨ鼀� �矄⼄盐�ᨨ 㦨nRT㦨

꾀�� P҈ =





ᨨ҈㦨

 ᆠ鼀矄矄ᨨ  �盐鼀�矄�  ᨨ 鼀㦨҈� 㡰   盐鼀ᨨ 鼀ᨨ矄ᨨ �矄B㦨n

 盐鼀ᨨ 鼀ᨨ矄ᨨ �矄꾀㦨҈

nRT ҈黨 Q U = g ҈  m = ҈ \ Um = U A + U B

( nA + nB ) RT g m ҈

=

ᨨ



ᨨ㦨nᨨn㦨

gRT M n A M A + nB M B ᨨ鼀� 盐M㦨 n A + nB (҈ ´ ) + (  ´ )  = g 鼀ᨨ ҈ M㦨 ҈+   ҈黨 ҈ ´  ´  ᨨ v = ҈鼀⏌矄 \v = ´ ҈  ´ ҈ 

㡰

和 ᨨ 矄ᨨ盐 v 㦨

V

(҈ + ) ´ ҈ ´ 

ᨨ P҈ =

䰘䰘黨 V

 ��㡰

 ���㡰

҈æ ҈ ҈ö ҈ é҈ ù  ÷=  ҈ú ç g çè P҈ ´ �g P҈ ÷ø gP҈ êë �g û ҈V é ҈ ù ҈ ᨨ DC = ҈黨 ´ 䰘䰘黨 êë �҈黨⏌҈ úû (҈ ´ 黨) V (҈ ´ ҈) V ҈V = 㦨 [ ҈  ҈] =  ҈黨 ´ 䰘䰘黨 ҈黨 ´ 䰘䰘黨 ҈黨 ´ ҈ \ DC =

n A RT nB RT + g A ҈ g B ҈

 �n ᨨ ҈ + ҈n = 黨 + ҈�n = +  

( n A + nB ) RT

盐� �盐ᨨ P҈P� ⼄ �㡰

n ҈+ n ҈ = + ҈黨 � 䰘 æ ö æ ö æ ᨨ ç ҈ ÷ ç ҈ ÷ ç ҈ ö÷ è ҈ ø è  ø è � ø

҈ (҈ + n )

 �㡰

V g g æ �V ö P æ V҈ ö = ç ÷ = ç ҈ ÷ = �g 꾀��  P҈ è V ø è V҈ ø ҈黨 ö g æ �� ÷ ᨨ P = P҈ ´ � ç 犨  g = è ø ҈

PVM ҈ ´ ҈ ´  =  Þ 鼀㦨҈�鼀 \ m = RT � ⏌  ´ ҈

\

҈ 盐├鼀ᨨ 盐盐矄 ( E )

\C =

꾀�├� �ᆠ �泐ᨨ  ᨨ鼀ᨨ 鼀ᨨ ᨨᨨ鼀�ᆠ �盐鼀

�矄⧤쟼㦨 \

gP dP dPV =  ᨨ  = gP dV V dV

ᨨ盐├鼀ᨨ 盐盐矄㦨쟼㦨g



 ´ � ⏌  ´

Þ ҈㦨 \ 㦨҈⧤ 㡰 鼀矄㦨 㝐  ´ ҈-

҈䰘

ᨨᆠ�泐ᨨ 矄ᨨ盐  v µ T \ v㦨 ᆠᨨ 矄 k㡰 T҈⏌

҈

㦨䰘V㦨䰘맔҈�V

ᨨ矄矄盐  泐 鼀� 盐P㦨҈�鼀

鼀盐T㦨⧤錐ᨨ盐鼀㦨鼀  x�鼀ᨨ \鼀矄矄ᨨ 꾀㦨 x㡰g

x 錐   - x 盐鼀ᨨ �鼀鼀ᨨ矄ᨨ 꾀�ᨨ n㦨 

盐鼀ᨨ �鼀鼀ᨨ矄ᨨ ᨨ n҈㦨

盐 ᆠᆠᨨ � � ᨨ ᨨ Ἐ矄 犨 ᨨ  �矄矄盐

n҈RT n RT + V V x RT x 㡰 RT  + ҈�㦨 V V

P㦨p҈졔p㦨 ᨨ

WWW.JEEBOOKS.IN

PS-141

Kinetic Theory

҈� ´  ´  Þ 㦨x졔 Þ x㦨䰘g ҈ ´ 

҈黨

\

nR T - T 㡰 g -҈    ´   - 㡰 㦨黨맔҈� 㡰҈졔 � -҈ 

㦨P҈ VV҈㡰졔

Pf㦨P鼀졔

Þ Pf㦨҈�졔

 ´ ҈ -

ᔼ  㝐ᨨ ᨨᨨ鼀�ᆠ ෌矄



㦨맔҈�⏌鼀 꾀鼀矄矄盐㦨҈�⏌鼀

҈㦨⧤

҈

k 㦨⏌鼀

�  ᨨ盐鼀 Vf 㦨V҈졔xA 㦨맔҈졔҈맔맔҈㦨맔҈鼀

PV 꾀泐� � ҈ � =

Pf V f

T�

ᨨ

Tf㦨

Tf

 Þ Tf 㦨

�ᆠ鼀

PV � �

 ´ ҈� ´  ´ ҈- ´  ҈� ´  ´ ҈ -

=  ⧤ 꾀

҈

㡰

\



\

P҈맔맔҈㦨맔맔 P҈㦨黨맔҈�鼀 ᨨᨨᆠ矄矄 ҈ ®  �矄ᨨ�ᆠ㡰



V҈ V ᨨ  =   Þ T 㦨⧤ =  T҈ T   ᨨᨨᆠ矄矄®  �b�ᆠ㡰 ҈

é T ù g -҈ é  ù � -҈ V㦨V ê  ú 㦨҈҈l =  ê ú ë  û  ë T û � ᲼Q g㦨  ᨨ鼀ᨨ ᨨᨨ鼀�ᆠ�矄桌 

ᨨ犨 PV㦨nRT





҈㦨





� ´ � ҈�

 鼀ᨨ矄 矄  ᨨ鼀 �� 鼀盐矄� ᨨᨨ犨鼀盐 矄�  盐 V

V

n

n ᔼ ��泐

TVg -҈ = TVg -҈ \





맔 㦨

��㡰 ᨨ �   � ᨨ盐鼀 矄矄盐ᨨ  �矄 꾀泐� � P҈V҈ 㦨 nRT҈

҈

�ᆠ鼀



P2

� ´ � ´  ҈� é  + � ù � ´ � ´  Þ 맔 ê úû =  ҈� ë +  ᲼Q  㦨 ҈ 桌 Þ 㦨䰘�ᆠ鼀 

 l





盐� � �矄盐ᨨ P҈� px㦨P҈x҈

㡰

l



P1

㦨҈졔�矄�  㦨҈졔� 和盐矄�盐� � �矄 盐�  ���㡰 ҈맔 ҈㦨᲼҈졔�桌맔  ᨨ ҈맔㦨᲼҈졔�桌맔�







x1

 ᆠ鼀 㦨

鼀� 矄� °  � 矄� ° = = 꾀 꾀 꾀 꾀 ´ �㡰 ´ � 矄� ° 㦨�矄�  ᆠ鼀ᨨ � 㦨 꾀

 ҈҈㡰

x

鼀 �ᆠ 

㦨

ᨨᆠ矄矄ᨨ PV ��鼀�矄矄矄 ᨨ犨 ᨨ犨 ҈㦨

x

x 2㦨

矄矄盐 盐ᨨ鼀ᆠ盐泐ᆠᨨ盐鼀

҈  Q㦨 P D V + nCv D T + k x  PV ҈ ҈ ҈ Cv DT + kx  㦨҈�᲼맔҈桌졔 RT҈  � - ҈ ҈ ´  ´҈  㦨졔 ´ ´  ´ � 졔 ´  맔҈㦨䰘   ´   �㡰

㦨黨졔䰘䰘㦨҈� 꾀 ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ ᨨ  盐 和� ᆠ 鼀盐 �矄   矄鼀 泐� � ᨨ泐Ἐ矄 犨 � PV 㦨 ᆠᨨ 矄 � 犨ᨨ矄� 矄ᨨ 鼀ᆠ盐ᆠᨨ盐鼀

맔 맔꾀㡰㦨맔 맔꾀㡰  맔 맔꾀㡰㦨҈맔 ҈맔꾀㡰 \ ҈맔 ҈맔꾀㡰㦨맔 맔꾀㡰 ᨨ ҈ ҈㦨   �㡰 犨 㦨҈졔矄矄盐 盐ᨨ鼀ᆠ盐泐ᆠᨨ盐鼀

Pf V f T�

 矄盐� 泐  �矄盐矄  ᨨ  矄�ᨨ ᨨ  �矄 � ᆠ矄� � �矄 鼀盐   矄ᨨ� � ᨨ �  �泐�    矄� �



nRT  ´  ´  = 㦨맔҈� ⏌鼀 V ҈҈ ´ ҈-

Q T㦨T҈��

���㡰 ␔ᨨ├ ᨨ 泐 �矄 W㦨W҈졔W

\ 㝐矄矄ᨨ ᨨ 㦨䰘g 鼀矄矄ᨨ 꾀�ᨨ 㦨䰘㦨黨g �  矄矄盐

kx A  ´ ҈

P㦨

Q 꾀泐� � PV 㦨 nRT ᨨ   盐 䰘맔㦨 맔䰘 Ἐ맔㦨 졔 㡰 맔䰘 �� � �犨� Ἐ + = 䰘

n졔x 졠ᔴ

n㜠x � 泐

졠ᔴ

ᔼ ��泐 � 泐  �㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-142

Physics

ᨨ��  盐 䰘맔㦨 맔䰘 Ἐ맔㦨  㡰 맔� 꾀��  �� � �犨�

 é   ù P ´ V - PV ú  êë   䰘  û æ黨 ö ҈� 㦨 - ç - ҈÷ PV = - ´ RT 㦨҈䰘�RT è ø  㦨 -

ᔼ ��泐 � 泐

 Ἐ - � = ´ 䰘 䰘

 ��㡰 

ᨨ鼀⼄ �㡰  ��㡰

+ - � = ´



䰘   Þ 㦨 

㦨

䰘 Ἐ  ´ 䰘 = 䰘� ᆠ鼀 � \Ἐ㦨 = ҈+  䰘  �㡰

 �㡰

Þ

 ´ Vg 

V æ  ö =ç ÷ V è  ø

�⏌

\

n㦨

҈� ´  ´ ҈ = ҈黨䰘 ´ ҈䰘  ´  ´ 

҈-g

ᨨ 㦨

 = 㝐 g - ҈㡰

 ´ ҈ 㦨�鼀矄҈  ´ ҈҈ - ҈㡰 ҈

� ҈㦨㦨鼀鼀�錐䁸 ҈㦨 錐㦨錐 ҈㦨  錐 㦨 ҈ 㦨黨黨

҈҈   ҈   ´ 黨黨

= = 䰘黨 鼀鼀�

҈

 \㦨 =

҈

҈- �⏌

æ  P ö =ç ÷ è  P ø

҈ 㝐 

R ҈ Mv = Cv  盐 Cv 㦨 g -҈  ҈ R  \ Mv =  g -҈

 ��㡰

꾀�� 盐矄� �PT⼄盐�ᨨ  ᨨ�� ᆠ 鼀�P҈gTg㦨ᆠᨨ 矄 

æ T҈ ö æ P ö ç ÷ =ç ÷ T è ø è P҈ ø



 ´ ҈ ´  = 㦨鼀⏌矄 㝐  ⏌҈

\

  V = V 䰘 䰘   ´ V ´ ´ T ᨨ鼀⼄ �㡰  ��㡰T҈㦨  V ´ 䰘 䰘 T = ҈黨T ᨨ T҈㦨 ҈ V҈㦨VV㦨V

g

v㦨

㦨nCvD 㦨҈맔Cv맔҈㦨Cv



V  Þ V㦨 䰘

盐 V҈졔V㦨V \

҈� 鼀

⧤쟼ᨨ ҈�鼀鼀ᨨᨨ ᨨ 泐� 

⏌ �

 �㡰

��㡰 ⧤� �ᆠ  �泐 ᨨ  鼀ᨨ�ᨨ  ᨨ  ᨨ 泐�  鼀ᨨᆠ盐矄 犨�  ᆠᨨ   � ᨨ   �泐

ᨨ �� ᆠ 鼀  ��ᆠᆠᨨ鼀矄矄�ᨨ  ᨨᆠᆠ盐矄 \P Vg = P ´

\ n 㦨

ᨨᨨ 鼀  矄⼄盐 ᨨᆠ�泐

PV P ´  = ´ V҈ T  ´ T҈  V҈T ´ V 

D Þ D = ´ D = ҈� ´ ҈ = ҈� D

맔鼀㦨҈�

ᨨ  ᆠ 鼀

Þ T҈㦨

ᨨᆠ 㦨맔꾀㦨҈�맔҈㦨҈�

ᨨ犨鼀ᨨ鼀 盐鼀ᆠ  �矄ᆠᨨ D㡰㦨 맔鼀  ��㡰 ␔  㦨 盐鼀ᨨ ᆠᨨ�矄�ᨨ 矄矄ᆠᨨ 矄⼄盐鼀 ᨨ鼀 �㡰  ��㡰

 ���㡰

和盐矄�盐� � �矄盐ᨨ  � ⼄ �㡰



�㡰

Þ

æ T ö ç ÷ è T ø

��㡰

␔ᨨ├ ᨨ 泐 �矄� �� ᆠ 鼀  ��ᆠᨨᆠ矄矄㡰

W㦨

҈ PV - PV 㡰 ҈- g

ᨨ

T㦨�T



\ ᨨ矄矄盐�  㦨䰘黨졔�㦨҈䰘鼀鼀� ᨨ鼀㦨

␔   矄鼀 n µ V 꾀矄ᨨ盐鼀矄矄鼀�҈ᆠᆠᨨ ᆠ  泐 ᨨ�  ᨨ 泐� 和ᨨ ᨨ 矄鼀矄犨� ⼄盐 盐鼀ᨨ 鼀ᨨᆠ盐矄

WWW.JEEBOOKS.IN

PS-143

Oscillations

Oscillations

13

Topic-1 : Displacement, Phase, Velocity and Acceleration in S.H.M. ҈

 㦨w 矄� w泐㦨w ᆠᨨ矄w  㦨w

㡰

҈ 

Þ  =   +  泐 +  

( w 矄� w ) + ( w ᆠᨨ矄 w ) 

Þ=



+ ( w )

 

 = w 

ᆠ㡰 ᨨ鼀 犨ᨨ鼀盐盐泐 �ᆠ盐和㝐矄 �  ⼄盐�ᨨ ᨨ �矄矄ᨨ盐矄 ��盐

x A



+

y B



-

㦨

ᔴ泐 A ¹ B   ᆠ �矄 b㡰 㝐 �鼀盐鼀 ᨨᆠ�泐�  和㝐 鼀 㦨 w 㝐 �鼀盐鼀ᆠᆠ�ᨨ � 和㝐꾀鼀 㦨w 犨  w鼀 �鼀盐鼀鼀�盐   �盐 ⼄盐 ᆠ泐 ෌�   

꾀 鼀 = ҈  鼀







b㡰 ␔├ ᨨ犨 㦨 w 꾀 -

æ 꾀 ö ᔼ ��泐 㦨 w 꾀 - ç ÷ è  ø



졠  �� � �犨�



꾀 ᨨᆠ�泐ᨨ 㡰 

p⏌

꾀҈ 㦨꾀



黨



�鼀㦨㡰



 p 



쟼⼄盐���盐鼀ᨨ�  꾀 

p 犨� 矄ᆠᨨx҈ t㡰矄矄 ᨨ犨 �   ��盐 

꾀 㦨꾀

é  꾀  ù 䰘꾀 꾀  黨 ê 꾀 - 黨 ú 㦨꾀Ἐ \꾀Ἐ㦨  黨 ëê ûú �

ᨨ = -  犨  �矄ᨨ矄��ᆠᨨ 矄  b㡰 犨ᨨ矄� 盐矄ᨨ�  �矄ᆠ鼀 矄x҈ t㡰㦨A矄� wt x t㡰㦨

f㦨 

␔ 꾀Ἐ㦨 � 鼀�盐  ෌�  㦨

æ 꾀 ö 꾀 - ç ÷ è  ø

 ᆠ ᆠᨨ泐 ᨨ  �ᆠ 犨� ᨨᨨ├ �├ 矄 ᆠ㡰 㡰 ᔼ � 和㝐 矄ᨨ� � ᨨᆠᆠ� �ᨨ �ᆠ矄 ᨨ盐 犨泐矄  ᨨᨨ�ᨨ  ᨨ   �矄ᆠ鼀  ᨨ    �ᆠ  �ᆠ  ᨨ犨 矄   ⼄盐���盐鼀 ᨨ矄��ᨨ  � µ

졔f㡰� �矄 鼀矄矄ᨨᆠᨨ鼀矄 �矄�矄ᨨ矄矄�犨    鼀�盐 ᨨ   �  B 㦨 A   �矄 � �   矄 �  ᆠ ᨨ



 æ 꾀 ö � 泐㦨 w 꾀Ἐ - ç ÷ è  ø

 㦨 ҈

p 錐 x t㡰 㦨 a   y t㡰 㦨  w

 ö æ p ÷  鼀�盐 꾀ᆠ 犨�  矄 �  ᆠ  ø è p ᨨ    ᔼ�矄��  矄� 盐矄ᨨ�  �矄ᆠ鼀 x t㡰㦨B 矄� wt 





ᆠ㡰 꾀 t 㦨  x t㡰 㦨  錐 y t㡰 㦨  x t㡰 �矄  矄� 盐矄ᨨ�  盐 ᆠ�ᨨ

A矄�  ç wt +

㝐 �鼀盐鼀ᆠᆠ�ᨨ 꾀鼀 㦨w㦨 �  鼀⏌矄

æ 꾀 ö 꾀Ἐ  - ç ÷ è  ø

q p 㦨

㦨 p  p 

꾀 t 㦨 䰘

�w㦨҈矄҈ �矄ᆠ鼀  �矄��  泐 㦨矄�  w졔p⏌㡰 㦨 㦨� �㦨矄� p⏌ �㦨矄� � Þ㦨 � 



p   

ᔼ  泐ᆠᨨ矄矄ᆠ ᨨ �鼀 

 xy ᆠᨨ矄 d = 矄�  d AB

x㦨A矄�  at졔d㡰 y㦨B矄�  bt졔r㡰 

꾀 �ᆠᨨ ᨨ鼀q㦨 㦨



㦨꾀 㡰 ⼄盐�ᨨ  ᨨ 和㝐x㦨a矄� wt

Þ

p æ p ö æ p ö x = a 矄� ç ÷ ´ t = ҈矄� ç ÷ t  = 矄� t è ø èT ø  Q a㦨҈ᆠ鼀T㦨s ᨨ鼀� 㡰

꾀 ᨨ ᨨᆠ�泐 v =

dx d é æ p ö ù p æ pö = ê矄� ç ÷ t ú = ᆠᨨ矄 ç ÷ t è ø dt dt ë è  ø û 

\ 꾀ᆠᆠ�ᨨ a㦨

dx dt 



æ pö æ pö = - ç ÷ 矄� ç ÷ t è ø è ø

WWW.JEEBOOKS.IN

EBD_8341 PS-144

Physics

꾀 t =

a㦨

= ҈

dx dt 



p  -p p æ pö = - ç ÷ 矄� ´ = 矄�

è ø   ҈ 

Þ

ᔼ 和㝐Y㦨A矄�  w졔j㡰 y҈㦨҈矄�  pt졔p⏌㡰

 ��㡰

Þ A =  x  Þ x =

é҈ ù  ᆠᨨ矄p ú 㦨҈矄�  pt졔p⏌㡰 \y㦨�맔 ê 矄� p + ë û  A҈

�ᨨᨨ 鼀�盐 矄 = = ҈҈㦨҈҈ A

bᆠ㡰 �� ⼄盐�ᨨ

x㦨A矄� wt졔Bᆠᨨ矄wt졔C矄� wtᆠᨨ矄wt  �� � ⼄盐�ᨨ  ᨨ和㝐 矄�  ᆠᨨ矄�  盐 ᆠ�ᨨ 矄 矄 ᨨ盐  � ᨨ犨

A B C 矄�  wt 㡰 +  ᆠᨨ矄  wt 㡰 + 矄� wt ᆠᨨ矄 wt 㡰    A B C 㦨 ᲼҈ - ᆠᨨ矄 wt 桌 + ᲼҈ + ᆠᨨ矄 wt 桌 + ᲼矄� w t 桌    C 㡰 ᨨA㦨 B㦨x㦨 矄� wt 㡰 

 ᨨ ⼄盐�ᨨ  矄 矄 和㝐 㡰 ᔼ A㦨B C㦨B  x㦨B졔B矄� wt

�矄�矄 ⼄盐�ᨨ ᨨ 和㝐 ᆠ㡰 A㦨BC㦨B錐 \ x㦨Bᆠᨨ矄wt졔B矄� wt

犨ᨨ 和㝐矄  矄盐ᨨ矄  ᨨ ��  ᨨ  和㝐 ⼄盐�ᨨ  㡰 A㦨BC㦨\ x㦨A

�矄 ⼄盐�ᨨ  ᨨ矄 ᨨ矄 矄 和㝐  ᆠ㡰 꾀泐� � 矄盐ᨨ矄��ᨨ  � ᆠ� y 㦨y҈졔y졔y 㦨a矄� wt졔a矄�  wt졔� 㡰졔a矄�  wt졔黨 㡰 㦨a᲼矄� wt졔矄�  wt졔黨 桌졔a矄�  wt졔� 㡰 㦨a矄�  wt졔� 㡰ᆠᨨ矄� 졔a矄�  wt졔� 㡰

Þ





Topic-2 : Energy in Simple Harmonic Motion ҈

ᆠ㡰

ᨨ鼀�  ⼄盐�ᨨ ᨨ  和㝐

X = A ᆠᨨ矄 wt ҈㡰

꾀

T  �ᆠ �矄  鼀  ᨨ矄��ᨨ  

\ 꾀ᆠᆠ�ᨨ 㦨 ᨨᆠ㦨

= A ᆠᨨ矄 wt

Þt=

T 

㡰 ⧤� �ᆠ �泐 ├ =

҈ 鼀w 꾀  ᆠᨨ矄  w 

҈ 鼀w  꾀  矄�  w  ├ p ҈ = ᆠᨨ  w = ᆠᨨ  ҈㡰 =  黨  ҈  ᆠ㡰 ᨨ � �泐 㡰 㦨 kx  ҈  ҈  ⧤� �ᆠ �泐 ⧤㡰㦨 kA - kx   꾀ᆠᆠᨨ � �ᨨ ⼄盐矄�ᨨ 㦨├

҈ ҈ ҈ \ kx  = kA - kx     A Þ 㦨꾀ᨨ x = ±  

b㡰 ᨨ�ᆠ  ᆠ盐� �和㝐 꾀鼀 ᨨ矄��ᨨ 錐t㦨wt㦨y㦨V㦨Vmax㦨aw

҈ mwa  T p 꾀 鼀ᨨ矄��ᨨ t㦨 w㦨 y㦨AV㦨Vm�n㦨  

\

K.E. 㦨KEmax㦨

\

K.E.㦨KEm�n㦨

⧤� �ᆠ �泐� SHMKE㦨

҈ ù mA w  ú  û

E矄盐 㦨  +  㡰 E矄� �

\





ᨨ �  �泐  =

ᔴ泐 矄盐 鼀ᨨ�ᨨ  �矄和㝐 ᨨ 鼀�盐  A㦨  + ҈ 㡰a   � �  矄泐�  ᨨ泐黨 �ᨨ  �矄

E矄盐  æ A ö  = ç ÷ =  + ҈㡰  =  +  㡰 è aø E矄� �

A

+A

\x㦨A犨 �ᆠ �矄 ᨨᨨ矄矄� \҈,  ᆠᨨᆠ

㦨  + ҈ 㡰a矄�  wt졔� 㡰 㦨A矄�  wt졔� 㡰

é ë

҈ ҈ k A - x  㡰 = kx   

A㦨鼀�盐 ᨨ 和㝐 x㦨 �矄ᆠ鼀  ᨨ鼀鼀 ᨨ矄��ᨨ

 �㡰

쟼 �泐E� 和㝐µ 鼀�盐 㡰 Q E = ê

T  �ᆠ �矄  鼀  ᨨ矄��ᨨ  矄ᨨ ᨨᆠ�泐 �矄 

鼀 �鼀盐鼀 꾀ᆠᆠ�ᨨ 㦨  㡰 ␔  ⧤쟼㦨쟼

\ x㦨

҈

꾀 t =

㡰

- p  ᆠ鼀 ⏌ s  

y㦨�矄� pt졔 �  ᆠᨨ矄pt

҈҈

㡰 꾀 T �ᆠ��    鼀 ᨨ矄��ᨨ  矄ᨨ ᆠᆠ�ᨨ  �矄 鼀 �鼀盐鼀

 s  ᆠᆠ�ᨨ



㦨 �

҈    mw a y 㡰 

҈ mwaᆠᨨ矄wt 

 ᆠ�  㡰ᆠᨨᆠ泐 �ᆠ矄├� �ᆠ �泐�鼀�  b㡰 和� ᆠ 矄泐矄鼀 �矄矄�矄 �矄  �泐 � 盐泐    ᆠ 鼀�盐 犨�矄ᨨ ᆠ矄矄犨�  �鼀 ᆠᆠᨨ � �ᨨ 㦨⏌鼀  �㡰 Q 쟼 �泐ᨨ ��ᨨ  ᨨᨨ  ᨨ �矄� ��盐 쟼㡰矄 쟼µÞµ 쟼

=

  ҈ -   Þ = =  鼀 ҈ ҈

ᨨ鼀 ⼄  �㡰

 =   -  ҈ 

WWW.JEEBOOKS.IN

PS-145

Oscillations 



҈ =  -  ҈ ᨨ  = ҈     =  \㦨�矄ᆠᨨ 矄 ҈ ҈ ҈    㡰 ⧤쟼㦨 k A - d 㡰  쟼㦨 kd  



é êë

㡰 ෌� U x㡰㦨K ҈ - e - x



ᆠ㡰

҈ - ᆠᨨ矄 wt ö y æ  ҈ - ᆠᨨ矄 wt 㡰  çQ 矄� wt = ÷ø è   y -y Þ y -  =  ᆠᨨ矄 wt   Þ y = A ᆠᨨ矄 wt y \ 꾀鼀�盐  =   Þ y=

꾀鼀 ᨨ矄��ᨨ d㦨꾀  鼀ᨨ矄��ᨨ 矄d㦨 꾀

䰘

҈ k ҈ YA = p m p mL y = y 矄�  wt f =

ù  \F㦨 - dU = kxe - x úû dx

 ᆠᨨ矄ᨨ � � u  x �  ᨨ    ��  u x㡰  㦨K ᲼҈ ex 桌 犨 �ᆠ  �矄   ᨨ  �泐� ᆠ矄� �� ᨨ  u  犨� x �矄矄矄 ᨨ犨 �   ��盐 U(x)

꾀 �盐 ᨨᆠ�泐㦨 w

ky k g = mg Þ = m y  꾀矄ᨨ 矄� � ᆠᨨ 矄  k = m w㡰  k g g ҈ g Þ w = = Þw= = m y  y  y

ᨨ⼄盐���盐鼀 ᨨ 鼀矄矄

C

K

B

A x x=0 ᨨ鼀 � ��矄ᆠ  ᨨ � �泐�矄鼀� �鼀盐鼀 x㦨 ᆠx㦨�矄 矄ᨨ 矄⼄盐���盐鼀ᨨ犨� 犨 �矄ᆠ �ᆠ ᨨ鼀x㦨   ᨨ �矄ᆠ鼀 矄 �ᆠ  矄ᨨ��  ᨨ矄��ᨨ x㦨犨�  ᨨᆠF㦨



黨

kx ex





ᨨ矄鼀盐矄ᨨ x犨 Fµx  ᆠ ᨨ 矄鼀 �矄ᆠ鼀  ᨨ鼀 x 㦨    鼀ᨨ�ᨨ  �矄 矄�鼀 鼀ᨨ �ᆠ ᆠ㡰 盐� � ᨨ  ᆠᨨ鼀 ᨨ矄ᆠ��ᨨ    ├� �ᆠ  �泐 ᨨ �ᆠ ᆠ盐� �和㝐犨�ᆠᨨ鼀鼀 �鼀盐鼀犨�ᆠ

 ᨨ  ⼄盐 ᆠ泐犨�  犨 �ᆠ �矄├� �ᆠ �泐ᨨ矄ᆠ�矄 犨�f

鼀� � � �泐㦨

Þ AἘ = 

ᆠ㡰

A 

T = p

l g

␔  �鼀鼀矄  ᨨ �矄ᆠᨨ盐矄�⼄盐�

g ö ҈� g æ amt = ç g - ÷ = ҈ ø ҈ è l ᨨ犨 T ¢ = p = p  

bᆠ㡰 쟼 �泐ᨨ  ᨨ矄ᆠ�ᨨ

҈  ҈   㦨 kA 㦨 ´  ´ ҈ ´ ҈㡰 = ҈    �

㝐  ᨨ矄��ᨨ

҈ æ ҈ ö ҈  ç kA ÷ø = kA Ἐ è 

A' 㦨犨 �矄 ᆠᨨ ᨨᆠ├ ᨨ鼀鼀  ᨨ矄��ᨨ

҈ ҈ mw  a  = m ´  p  v  a    ҈  � � ´ ´ a  \ a = 鼀 Þ 黨㦨 ´  ´ p ´  p p

쟼 鼀 ᨨ矄��ᨨ

ᆠ㡰

l t = -⧤ ᆠᨨ矄 q 

k=

YA L

Dl ù l úû

=



҈�

T

=

l 

q

b㡰 꾀  矄�ᆠ 犨� ᆠ     矄 矄� �  �矄 矄� � ᆠᨨ 矄 

é F êQ Y = A ë

l

҈� g ҈

ᨨ⼄盐 盐ᨨ矄� � ᨨᆠ

x㦨A x㦨 ⧤쟼㦨 ⧤쟼㦨҈ E㦨҈ E㦨҈ 쟼㦨҈ 쟼㦨 Topic-3 : Time Period, Frequency, Simple Pendulum and Spring Pendulum ҈

҈  kA 

꾀⼄盐���盐鼀ᨨ矄��ᨨ   ᨨ  鼀矄矄ᨨ ᨨᆠ├├矄ᨨ 矄ᨨ �矄 ᨨ �  �泐ᆠᨨ鼀矄  

� ෌� m㦨├�w㦨 ⧤쟼㦨� 쟼㦨 p

ᨨ鼀ᆠ  �ᆠ �泐E㦨҈

҈  kx 

꾀 鼀  ᨨ矄��ᨨ  ᨨ � �泐 =

꾀矄ᨨ 쟼 㦨

҈

ᨨ � �泐ᨨ 矄� � =

x㦨 �矄 ᆠᨨ ᨨᆠ├ ᨨ鼀鼀  ᨨ矄��ᨨ  k㦨矄� �ᆠᨨ 矄 

  ᆠ

 a㦨䁸

쟼㦨⧤쟼졔쟼㦨 �졔㡰㦨黨

㡰

q



⼄盐 ᆠ泐ᨨ  ᨨ矄ᆠ��ᨨ 

WWW.JEEBOOKS.IN

EBD_8341 PS-146

Physics

æ ⧤l  ö Þ t=ç ÷ q = -ᔴq è  ø

é ⧤l  ù ê ᔴ = ú  úû êë

\ f2 =  f1 Þ



㡰

⧤l  = ҈ ⧤ 㝐l  p 㝐 ҈

҈ ᔴ ҈ = p ᔼ p

=

�ᨨ ҈

෌�  y㦨 � éë矄� p㡰 +  ᆠᨨ矄 p㡰 ùû

㡰 꾀ᆠᆠ�ᨨ  盐ᨨ��泐�㦨

㝐 æ  = ç �  㝐  çè 

㝐矄矄ᨨ ᨨ ᨨ鼀ᨨ 矄�㦨

҈҈

 㡰





 ⼄盐���盐  㦨鼀�

҈



҈

盐矄� �㦨w

f =

҈ C p ҈

҈ C  ML ҈ p

p  =

├ 鼀

鼀㦨҈├�

C M Mö æ L ç + ÷  ø è 

꾀矄 ⼄盐 ᆠ泐 盐ᆠ矄 泐奠

=

҈ ├´ ҈ =  p � 

ᆠ㡰

�鼀ᨨ矄⏌��   泐 =

├� ҈ µ Dq ´   矄ᆠᨨ 

꾀矄犨 ├ ᨨ犨�鼀 �ᨨ   = p

ᆠ㡰

l �

␔    ��ᨨ 鼀矄矄㝐�矄   

p  r� 鼀

l + Dl g

TM = p

␔;䰘黨� 矄҈

 =

Þ

҈ ├ = ҈  p 鼀

q㦨q q㦨҈Þ q 㦨� ᔴ



f҈ 㦨

⼄盐 ᆠ泐ᨨ 矄� � 㡰 =

҈ a   q㡰 ´   �㡰  ҈  = a q  㡰 ´   ��㡰    q 졠  �� � �犨�  = q  

( p r� ) 㦨

ᆠ㡰

ᆠ㡰

҈ =

鼀� 쟼 ᨨ泐  ᨨᆠ㦨r꾀 � 졔㦨鼀�졔鼀 \㦨鼀㦨r꾀 �㦨 pr�㡰

黨

)

´҈- ├�

ᔼ ᨨᆠ├ᨨ 鼀矄矄鼀㦨҈├��矄ᆠ     ├㦨p ᨨ犨�  �ᆠ矄� �矄ᆠ  � 犨�  鼀矄矄鼀㦨 ├� ᆠ ├⼄㦨├  ├

ᨨ 盐矄㡰

Þw=

 ´ ҈

和ᨨ� �犨�矄� �ᆠᨨ 矄  ⧤㦨䰘҈⏌鼀

෌㝐 





(

҈

҈ ├ ´  ´ ҈ = ҈҈ p ҈ ´ ҈-

Þ  =   矄 

҈ ├ = ҈҈ p 鼀

犨 鼀㦨鼀矄矄ᨨ ᨨ ᨨ鼀

 ö æ҈ö ҈ ÷÷ =  ç ÷ = èø  ø

 ҈ � 꾀矄ᨨ µ Þ = =  � � 

�

鼀 㦨 䰘 㝐

b㡰 꾀矄犨├ ᨨ犨 ⼄盐 ᆠ泐� 和㝐 㦨

pö æ Þy㦨 ҈矄� ç p + ÷ ø è \꾀鼀�盐 㦨҈ᆠ鼀 p p  㦨 㦨 矄

�鼀�ᨨ  㦨 w p  䰘

 ���㡰

和ᨨ� �⼄盐�ᨨ 矄 �㡰 ��㡰 ���㡰

Þ和ᨨ ⼄盐 ᆠ泐ᨨ 矄盐� �ᨨ矄ᆠ��ᨨ 矄



f =  f҈

㝐 =

 �㡰

l + Dl l 

⏌

⏌





 ��㡰 㝐 

l + Dl æ 㝐 ö = ÷ è ø l

Þç



㝐� æ 㝐 ö = ҈+ ᨨ ç è ÷ø 꾀Ӹ \

 ù 꾀 ҈ éæ 㝐 ö = êç - ҈ú ÷ Ӹ êè ø úû 㝐� ë

㝐�l ù é êëQ Dl = 꾀Ӹ úû

WWW.JEEBOOKS.IN

PS-147

Oscillations ҈

㡰 ᔼ  矄�鼀 鼀ᨨ �ᆠ鼀ᨨ�ᨨ 矄� � ᨨ鼀 矄 꾀t㦨x㦨A x 㦨 꾀ᆠᨨ矄w  �㡰 ␔  t㦨 t x㦨Aa ␔  㦨 t x㦨Aa ᨨ鼀 ⼄盐�ᨨ  �㡰  ��㡰 Aa㦨Aᆠᨨ矄w t Aa㦨Aᆠᨨ矄w t  ���㡰 꾀矄ᆠᨨ矄w t 㦨ᆠᨨ矄 w t ҈ �㡰 ᨨ鼀⼄盐�ᨨ  ��㡰 ���㡰  �㡰

æ P xg ö Mg - ç   g ÷ A = F矄ᨨ� � ç x - x㡰 ÷ è  ø g æ ö x ÷ = F矄ᨨ� � ᲼ x - x » x 桌 P A ç҈ g   ç x - x㡰 ÷  è ø gP Ax F=-  x



\ ⼄盐 ᆠ泐 犨�  犨 �ᆠ  �矄ᨨ   ᆠ盐矄 和㝐

A - a æ A-a ö = ç ÷ -҈ A è A ø A - a  A + a  -  Aa - A = Þ A A Þ

AaA㦨A졔aAa

Þ

a ҈ a㦨aAÞ A㦨aÞ = A 

҈

҈�

ᆠᨨ矄 wt =

A- a ҈ Þ ᆠᨨ矄 wt = ᨨ A 

Þ 㦨 t b㡰 ᨨ鼀� ��矄 ᆠ  犨 

㦨҈鼀 㦨矄 꾀矄 犨 ├ ᨨ犨



\ ҈

p p t=  T

+ ҈㡰 ҈ =



+ ҈㡰 ´ p



æ  ö ҈ æ  ö ÷ ´ =ç ÷ è 䰘 ø  è 䰘 ø  �= = 黨䰘鼀 ⏌ 矄  黨

҈黨

ᨨ

鼀 p 鼀 = p ᨨ w ⧤ ⧤

҈ = �

ᆠ㡰

҈ [Q 鼀 = ҈├�錐 w = �  ⏌ 矄 ] ⧤

� 鼀矄 -҈

 ᆠ�矄ᨨᆠ 犨�  矄 V㦨 � 鼀矄҈ 㡰 ᔼ  矄� �ᨨ 矄� �ᆠᨨ 矄 k҈�矄ᆠᨨ鼀矄矄 泐x҈   ᨨ 矄� �ᆠᨨ 矄 k �矄ᆠᨨ鼀矄矄 泐x  

x҈ = ҈

… ��㡰

ᆠ㡰 ᨨ鼀 ��盐ᆠᨨ鼀矄矄�ᨨ ᨨ  矄� �x㦨

ì î

�矄ᨨ

L q 

L ü qý L  þ

꾀矄ᨨᨨ⼄盐㦨Ia㦨

kL 

æ kL ö ML  a = -ç ÷q ç  ÷ ҈ è ø

L⏌

x q



P Ax g = PA x - x 㡰 g



… �㡰

k A k + k҈

ᨨ⼄盐㦨 í k 㡰 

㝐� 㦨 꾀 … ҈㡰 �矄ᨨ  �矄 �矄ᆠ  泐 �矄 ᆠ x

x - x 㡰g

\ V =

和ᨨ� �⼄矄 �㡰 ��㡰犨�

PV g = PV g

P=

V 矄� �º g

kx  k҈ x҈ = k x Þ x = ҈ ҈ k

Mg = P A

g P x

҈=

V sin q g

x҈ + x = A

ᨨ ⧤㦨�鼀҈

鼀 �鼀盐鼀 ᨨᆠ  泐 矄泐矄鼀ᨨ   ᨨᨨ 㦨㝐�졔⧤ 졔鼀� 㦨맔҈졔�맔҈맔҈졔҈맔҈㦨졔҈졔҈㦨 ҈䰘

\



 l = 㡰 ´ p � �

Þ 㦨҈ \ 졔҈㦨҈졔҈㦨 㡰 �鼀ᨨ  �� ᨨ  ᨨᆠ� T㦨

ᆠ㡰 㝐矄矄ᨨ ���ᨨ 泐㝐㦨 ├� 㝐矄矄ᨨ 矄鼀ᨨ 泐鼀㦨҈ ├� 和鼀鼀矄矄 鼀㦨҈├�㡰 ᆠ盐矄和㝐ᨨ  �盐 ⼄盐 ᆠ泐w 㦨� ⏌矄 꾀鼀�盐  㦨҈ᆠ鼀㦨҈맔҈ 꾀矄 犨 ├ ᨨ犨

= p

 ҈    = p � �

꾀矄 l҈ < l    ᨨ ҈ <  㦨 泐矄矄犨� �� �ᨨ� 和� ᆠ ��鼀�ᨨ 矄  �    矄犨� �� � 犨� ᨨ  �  盐 �矄ᨨ  犨泐矄 졠 泐 犨   盐鼀ᨨ ᆠᨨ鼀 ᨨ矄ᆠ��ᨨ 矄 � 泐  � �  犨ᨨ 盐盐鼀矄犨��� �� ᨨ矄犨� �ᨨ�  ᨨ �  �   盐盐鼀 ᆠᨨ鼀  ᨨ矄ᆠ��ᨨ    矄 ᨨ  �  盐盐鼀ᆠᨨ鼀 졔҈㡰ᨨ矄ᆠ��ᨨ  ᨨ盐 �矄ᨨ 矄犨� �� �

  p 

= p Þ � = �

 㦨  ´ ç

gP A MV

  ҈      �鼀�ᨨ  ᨨ   犨ᨨ  盐盐鼀矄

㡰

҈ = p

ᨨ犨Aa㦨꾀ᆠᨨ矄wt Þ

gP A ҈ x M 㦨 p

҈ p

f =

ᔴ泐�  ᆠᨨ � � � � �矄

҈ æ ö çQ I = ML ÷  è ø

q

L⏌

x

WWW.JEEBOOKS.IN

EBD_8341 PS-148

\ \ 

b㡰 \ ᨨ

Physics

҈ k w = f㦨 p p M

dy d y = v = kt   = a = k dt dt  ay = 鼀 ⏌ 矄   Q k㦨҈鼀⏌矄�� 㡰

l l ᨨT҈㦨 p g g

T҈

\

T

=

g + ay g

\

᲼k桌㦨

 Þ 

k = m+m

T҈ T

=

҈  = ҈ �

\

è m ø

ᨨ

m

æ kA ö kA = mç = è m ÷ø 

Ӹ g  g 矄�  a 㦨ay g 矄� a g 矄� a 矄� a  g ᆠᨨ矄 a 矄�   a 㦨ax



g 䰘

a ax = g 矄� a ᆠᨨ矄a 㦨aᆠᨨ矄a ay = g  g 矄�  a = g ҈  矄� a㡰 㦨 g ᆠᨨ矄 a

 ᆠ�ᆠᆠ�ᨨ  盐ᨨ��泐ᆠ� �ᨨ  ᨨ

㦨

g 矄� a ᆠᨨ矄 a + g ᆠᨨ矄 a

㦨gᆠᨨ矄a 矄�  a + ᆠᨨ矄  a \



T㦨p

L geff

㦨p

L g ᆠᨨ矄 a

kk Ἐ k +kἘ  �㡰

Y, AL

k҈㦨

k

F YA 㦨 l L

YA L

k



m

m

\

ᨨ

k҈㦨

\

T㦨 p

�㡰

YA L

��㡰

  ��㡰

m k + k҈ 㡰 m 㦨 p keq kk҈

YA ö æ mçk + ÷ m YA + kL㡰 L ø è 㦨 p 㦨 p YA YAk k´ L x 㡰  A㦨L q㦨 L 㝐ᨨ 盐盐矄ᨨ ��� �泐h㦨F⏌Aq \ 矄ᨨ� � ᨨᆠ F㦨hAq㦨hLx ᨨ ᆠᆠ�ᨨ  a㦨



keq㦨

ᨨᆠ 㦨k  �

ᨨᆠ YA 㦨  � L

ax + a y 

Þ

F L Y㦨 A l

㡰 꾀矄矄 ᨨ犨  �    ��盐 ᆠᆠ�ᨨ  ᨨ犨      a 㦨 gs�na �矄  矄盐 ᨨ ᆠᆠ�ᨨ  �  泐  ᨨ矄 �    ᆠᆠ  鼀



= ML-҈T -

҈

ᨨ 犨�

k m

�矄 ᆠᆠ�ᨨ  ᨨ   ᨨ犨 ᨨᆠ├ �矄 ᨨ�   泐 �ᆠ�ᨨ

\ 㝐 �鼀盐鼀 ᨨᆠᨨ  �ᆠ�ᨨ



L

ᨨᆠᆠᨨ 矄  ᨨ 矄� �㦨k



geff㦨

MLT -

҈ ҈ ҈ = + keq k k Ἐ

a鼀 = Aw = A æ k ö = KA ç ÷



᲼ x 桌

=

b㡰 盐矄ᆠᨨ 矄�  犨�矄ᨨ矄矄� �ᨨ 矄� �ᆠᨨ 矄  k'   ᆠ矄ᆠᨨ鼀矄 ᨨ 犨ᨨ矄� �ᆠ  � 矄�矄

 ⼄盐�  矄� � ᆠᨨ 矄 

㝐 �鼀盐鼀ᆠᆠ�ᨨ  ᨨ  矄泐矄鼀�  和㝐

f鼀 = ma鼀

᲼U 桌

a 

㡰  ᆠᆠ�ᨨ  �矄矄鼀 ᨨ ᨨ  P   Q 矄 ᨨᆠ├ Q ᨨ矄ᆠ�矄 盐  ᨨ矄  ᨨ 矄�    P  Q㡰 矄泐矄鼀 ᨨ矄ᆠ�矄 犨�  �盐 ⼄盐 ᆠ泐w 矄� ��矄矄ᆠ  泐A 꾀 �盐 ⼄盐 ᆠ泐ᨨ   矄泐矄鼀

w=

෌� U x㡰㦨kx

 ᨨTµ

l g + ay

T㦨 p

㡰

ᨨ犨 �鼀 �ᨨ  鼀泐   ᨨ  T µ 鼀矄矄㡰 x 鼀�盐 㡰y k㡰z \ ᲼MLT桌㦨᲼M桌x᲼L桌y᲼ML҈T桌z 㦨᲼Mx졔zLyz Tz桌 쟼⼄盐� � ᨨ犨矄犨� z㦨҈ᨨz㦨҈⏌ yz㦨ᨨy㦨z㦨҈⏌  ᆠTµ 鼀�盐 㡰҈⏌ µa҈⏌

෌� y㦨kt

␔├ ᨨ犨 T㦨 p



�

æ k ö  ÷q = - w q èMø

a㦨 - ç

x

 q

F hL =x M M

和� ᆠaµx和ᨨᨨ矄ᆠ��ᨨ 矄和㝐  ᨨ�鼀�ᨨ ᨨ 犨 �ᆠ �矄�� 泐

㦨gᆠᨨ矄a ᨨ

T㦨p

�矄ᆠ鼀  x 㦨 p ᆠᆠ�ᨨ

a

T㦨p

M hL

WWW.JEEBOOKS.IN

PS-149

Oscillations 

b㡰 ᔼ x�矄  �矄ᆠ鼀    矄ᨨ� � ᨨᆠ㦨 盐 盐矄졔 矄� � ᨨᆠ \

M w  x = [ rAg + k ] x

é rAg + k ù Þ w㦨 ê ú ë M û

黨

҈⏌

҈ é rAg + k ù  Þ v㦨 p êë M úû

҈⏌

ᔴ泐쟼҈>쟼

㡰 ෌� 鼀 �鼀盐鼀ᨨᆠ�泐v҈㦨v ᨨa҈w҈㦨aw Q V鼀 �鼀盐鼀 㦨 aw Þ

\



æ ö æ 㝐 ö çQ  = ç ÷ ҈ ᨨ鼀 ⼄ �㡰 ÷ 㝐 鼀 + è ø è ø  㝐  ҈ ҈æ 㝐 ö  맔 㦨 ç ÷ ҈ 㝐 + 鼀㡰  è㝐+鼀ø

a҈맔

p p = a ´ T҈ T

a҈ T҈ = = a T

m p k҈ m p k

ᔼ 矄  ᨨ盐矄 矄    ᨨ   ᆠᨨ鼀�   鼀矄矄矄 㦨

=

k k҈



盐

�盐

 ᔴ

         ��㡰

盐



�盐

쟼⼄盐���盐鼀ᨨ矄��ᨨ

 ᨨᆠ�泐 ᨨ   �ᆠ ᆠᨨ鼀矄 �u   �鼀 t 矄� � ⼄盐�ᨨ 㦨鼀 ᆠᨨ矄wt �u㦨uᆠᨨ矄wt

├�ᨨᆠ├犨� ᨨ鼀和㝐 ᆠᨨ�矄�ᨨ 矄ᨨ矄� �盐 矄ᨨ �矄 盐 矄ᆠ  ᨨ矄��ᨨ  ᨨ  �矄 �鼀  

T m  =p = p 㦨҈矄 㦨 p  k 

ᨨ  �矄�鼀㦨t㦨



\

㝐 꾀㦨 꾀 꾀 Þ 㝐+鼀 ҈

㦨

p 

鼀 p + ├ 

㦨

䰘π 

鼀  ├



A = A҈

҈ 꾀矄ᨨ 쟼҈㦨  㝐҈ 

҈ ҈ 㝐졔鼀㡰㦨 㝐졔 鼀㡰  

T 

鼀 p 鼀 \t㦨 ├  ├

鼀 é҈ ҈ ҈ ù 鼀 π 鼀 + =π 졔 졔 ├  ├ ├ êë    úû

 �鼀 ├  ᨨ �ᆠ ᨨ 矄矄  ᨨ盐�    ⼄盐���盐鼀 ᨨ矄��ᨨ  矄ᆠᨨ  �鼀

⧤ 㝐+鼀

M M +m

p 鼀   ├

�鼀├  ᨨ 鼀 �鼀盐鼀ᆠᨨ鼀矄矄�ᨨ

㦨t꾀졔t꾀졔t꾀ᔴ

㝐 ҈㦨 㝐졔鼀㡰  �㡰 㝐 꾀҈ 맔 w҈㡰 㦨 㝐졔鼀㡰 꾀맔w㡰

⧤ 㦨 㝐졔鼀㡰꾀 꾀맔 㝐

t=

 �鼀 ├  泐  �ᆠ ᨨ矄矄  ᨨ盐�    ⼄盐���盐鼀

b 㡰 ᔴ矄  �㡰  꾀泐� � � ᆠ� ᨨ  ᆠᨨ 矄�ᨨ  ᨨ  �  鼀ᨨ鼀 盐鼀

㝐꾀҈맔

Þ

�鼀�ᨨ  =  p

 ´ ҈ 㦨黨㦨黨鼀 

\

p p = ´T  t

\

�矄 ᆠ ᨨ ⼄盐�  矄�ᨨ  犨    ᨨᆠ├矄

 쟼㦨

V = ҈ Þ㦨�u �u

�.e.   �ᆠ ᨨ盐 矄 犨�    矄鼀 矄   ᨨ   �ᆠ 犨�盐  ᨨ �矄 ⼄盐���盐鼀 ᨨ矄��ᨨ  犨�  矄  u

  v㦨 鼀⏌矄v҈㦨 鼀⏌矄  

҈

e=

 v҈ + v

Þ v졔v҈㦨 ᨨ鼀⼄矄 �㡰  ��㡰

㦨v҈t㦨

鼀+㝐 ⧤

꾀矄ᨨ꾀㦨꾀҈  쟼㦨 쟼҈ ᔼ   �矄 ᆠ矄 矄ᨨ � 矄  ᨨ盐矄 矄   ᨨ ᨨ    ᆠᨨ鼀�  鼀矄矄矄 ᆠ矄矄  㡰  �ᆠ ᆠᨨ� 矄 矄�ᆠ泐 犨�  ���  犨 \

ᨨ鼀 鼀ᨨ鼀 盐鼀 ᆠᨨ 矄�ᨨ  � ᆠ� m҈u҈졔mu㦨m҈v҈졔mv 졔҈맔㦨҈v҈졔v  �㡰 ᔴᨨ�矄�ᨨ �矄矄�ᆠ ᆠe㦨҈

t㦨

㝐҈ ҈ 㝐+鼀

ᔴ矄 ��㡰  犨�鼀�ᨨ  㦨

黨㡰 ᨨᆠ��矄ᨨ ҈├� ├�ᨨᆠ├矄盐矄 ᆠᨨ�矄�ᨨ v҈ v 矄ᆠ�泐 盐矄 ᆠᨨ�矄�ᨨ

v v҈ ҈├� ├�

e㦨҈㦨

鼀+㝐 ⧤

 犨�鼀�ᨨ  㦨

éπ

㦨  ê

ë



鼀ù ú졔π ├û

鼀 æ ö � 鼀 鼀 㦨 π ç 졔 ҈÷ 㦨 π ├ è ø  ├ ├

 和㝐a �矄 ᆠyᨨ 鼀 ᨨ矄��ᨨ ᨨᆠ�泐ᨨ ᨨᆠ├ v = w a  - y  꾀  ᆠ � � ᨨ鼀 矄� �  ᨨ犨 犨  ᆠᆠ�ᨨ  ᨨ    ᨨᆠ├㦨g \ �� �  泐 ᨨᆠ├㦨h

WWW.JEEBOOKS.IN

EBD_8341 PS-150

Physics

(

)

w a - y v ᨨ h = y + \ h= y+ g g dh ᨨhᨨ鼀 �鼀盐鼀 =  y = y ã dy  dh w \ = ҈+ ( - y ã) ᨨ  = ҈ - w y ã dy g g

 p 㦨 q

w y ã g = ҈ ᨨ y ã = g w 和� ᆠ aw  > g ( �� )

g

ᨨ盐鼀ᨨ  ᨨ 㦨LS ␔�� ᨨ  ᨨ 㦨LSd҈g  盐矄ᆠ� �ᨨ ᨨ 㦨LSdg 和� ᆠd>d҈ �� 㡰 \  ᨨᆠ ᆠ� �   ᆠ  ᨨ 鼀矄矄 ᨨ    ᨨ   �  ᨨ矄��ᨨ

LSdgLSd҈g㡰

ᨨ⼄盐ᨨ盐 �矄 ᨨᆠᨨ盐P t㦨F맔r҈㦨 LSdgLSd҈g㡰맔PN

L \ t㦨LSg dd҈㡰맔 矄� q  犨   q �矄矄鼀矄� q » q \

t㦨

L Sg d  - d҈ 㡰q 

ᨨ ᨨ

LSd 2g

\ q q

L/2

M

\

LSd 1g P N

=

d2

��㡰

L Sg d  - d҈ 㡰 

Þ Iw 㦨

L Sg d  - d҈ 㡰 

 ��㡰

鼀ᨨ鼀 ᨨ � �Iᨨ  ᨨ ᨨ盐P I㦨

҈ ҈ ML = LSd҈L  

҈ a p q ҈ k ⼄盐 ᆠ泐ᨨ ᆠ   = p m ⼄盐 ᆠ泐ᨨ  ᨨ矄ᆠ��ᨨ  f =

҈  ´ ҈ ҈ = 矄ᆠ -҈  ��㡰 p p ҈ v鼀  ᨨᆠ�泐  鼀  ᨨ矄��ᨨ



L L Sg Sd҈ = d - d҈ 㡰    d - d҈ 㡰 g Sg d  - d҈ 㡰 Þ w㦨 Þ w㦨 d҈ L  LSd҈ w ´

I a = - kR q 犨 a㦨 �盐ᆠᆠ�ᨨ

æ k ö mR㡰a㦨kRq ᨨ a = - ç ÷ q è mø

㦨黨�맔҈

盐� � �矄盐ᨨ I� ⼄ ��㡰 



졠 㝐

 ᆠ �盐 ⼄盐 ᆠ泐ᨨ ᨨ矄ᆠ��ᨨ 

g d - d҈ 㡰 w㦨 d҈ L �



\ ᨨ矄矄� 矄�ᆠᨨ � �泐㦨�� � ├� �ᆠ �泐  é҈ æ pö ù é҈  ù  ê K ç  R ÷ ú =  ´ ê mv鼀 ú  ø úû ë û êë  è K Rp ´ =  p 鼀⏌矄 㦨鼀⏌矄 \ v鼀 = m  é҈  ù ���㡰 ᨨ �泐㦨  ê mv鼀 ú 㦨 ⧤쟼鼀  ᨨ矄��ᨨ 㡰 ë û ҈ é ù 㦨  ê ´ ҈ p㡰 ú ë û

 �㡰

和� ᆠt µ q  ᆠ鼀ᨨ�ᨨ �矄矄�鼀 鼀ᨨ �ᆠ 졠 ᆠᨨ鼀� ��犨� t㦨C q犨� C㦨

q

ᔴᨨ鼀矄矄�ᨨ 㦨Rq㦨ᨨ ��ᨨ 㦨x \ ᨨᆠ  泐ᆠ 矄� �ᨨ ᆠ 㦨kx \ ᨨ ᨨᆠᨨ ᆠ  盐ᨨ犨ᨨ矄� �矄㦨kx \ 矄ᨨ� �ᨨ⼄盐ᨨ盐ᨨ��� O㦨 kx㡰R \ t㦨k Rq㡰R犨 q㦨꾀 �盐 �矄ᆠ鼀  ᨨ t㦨kRq 和� ᆠᨨ⼄盐 t㡰�矄ᨨᨨ�ᨨ ᨨqᆠ   ᆠ盐矄 �盐 和㝐ᨨ盐  ᆠ  O 꾀�� t㦨kRq

\ a > y ã y ã  ᨨ鼀鼀 ᨨ矄��ᨨ a w g  ᆠ yã =  w 

q R



ᨨ

\ a >



�㡰 ෌� 盐 � ᨨ 矄� �l㦨p㦨pR 和� �ᆠᨨ 矄 k㦨҈⏌鼀 㝐矄矄ᨨ ᆠ ᨨᆠ├꾀 m㦨҈├�  �盐矄ᨨ ᆠ�ᆠ 㦨鼀 꾀矄ᨨ  矄 �矄ᆠ 泐  � q = p ⏌   � 犨� 矄ᆠᨨ  �鼀PQᨨ  ᆠ�ᆠ 矄  ᨨ鼀矄ᔼ 矄盐矄 � ᨨ ᆠᨨ鼀矄矄�ᨨ  ᨨ  矄� � �  盐 矄�鼀    

⼄盐ᨨ ��ᨨ ᨨ 矄� �� ᨨ犨矄�鼀 �xPB QA  ᨨx�   ��盐



q -q �





�

턼 ⧤

鼀�

鼀҈�

꾀 ⼄盐���盐鼀

æ ᨨ⼄盐  ⼄ 盐 ᨨ ö æ ᨨ⼄盐   盐 ᨨ ö ç ÷= ç ÷ è �⼄盐� ᨨ  矄�泐 r ø è �⼄盐� ᨨ  矄�泐҈� r ø mg맔QM㦨m҈g맔PN

WWW.JEEBOOKS.IN

PS-151

Oscillations mg R矄�  � 졔 q 㡰㦨m҈gR矄�  �  q 㡰

\

VrgR矄�  � 졔 q 㡰㦨҈�VrgR矄�  �  q 㡰

Þ

矄� � + q㡰 = ҈� 矄� � - q㡰

Þ

矄� �° ᆠᨨ矄 q + ᆠᨨ矄 �° 矄� q  = 矄� �° ᆠᨨ矄 q - ᆠᨨ矄 �° 矄� q 

꾀�� �鼀├ ᨨ ᨨ鼀ᔴ ᨨ  �㡰

和ᨨ� �犨�

 q =

t㦨

\ ᨨ �鼀 ᨨ  ᨨ矄ᆠ��ᨨ

㦨t҈졔t졔t졔t 㦨䰘�졔�졔҈�졔�㦨 꾀ᨨ �鼀泐㡰 

҈ �

㡰  盐矄 ᨨ犨 �矄ᆠ   �⼄盐� 矄 �   �ᆠᨨᆠ├犨�矄  �ᆠ�ᨨ

ᨨ � ᆠ�ᆠ盐鼀  ᆠᨨ 盐 ᨨ盐�   �a \ᨨ⼄盐 t㦨mgR矄�  � 졔 q 졔a㡰m҈� 矄�  �  q a㡰 㦨VrgR矄�  � 졔 q 졔a㡰҈�VrgR �  q a㡰 㦨 VrgR 矄�   q 졔 � 㡰 ᆠᨨ矄 a  졔 VrgR ᆠᨨ矄  � 졔  q 㡰 矄� a ҈� VrgR矄�  �  q㡰ᆠᨨ矄a 졔҈�rgRᆠᨨ矄 � q㡰矄�  a 矄� �⼄ �㡰犨�

m m

1

m

2

2

x҈   矄�ᨨ � ⼄盐���盐鼀犨  ᨨ m҈ m 矄盐矄   \

m҈ + m 㡰 g k

m҈졔m㡰g㦨kx҈Þx҈㦨

t = V rgR éëᆠᨨ矄 ( �° + q ) 矄� a + ҈�ᆠᨨ矄 ( �° - q ) 矄� aùû

x   矄�ᨨ 犨  ᨨ 泐m�矄 

t㦨VrgR᲼ᆠᨨ矄 � 졔q㡰졔҈�ᆠᨨ矄 � q㡰桌矄� a 犨  a�矄矄鼀 �� 㡰 \ 矄� a » a \ t㦨VrgR᲼ᆠᨨ矄 � 졔q㡰졔҈�ᆠᨨ矄 � q㡰桌a 和� ᆠt a ᨨᨨ�ᨨ 鼀ᨨ�ᨨ  �矄 矄�鼀 鼀ᨨ �ᆠ 㝐ᨨ鼀  ᨨ  � �ᨨ盐 O I㦨m҈R졔mR㦨VrR졔҈�VrR㦨�VrR

\

ᨨ犨 ᨨ鼀

ᨨ

T㦨 p

A㦨x҈x㦨

w㦨 黨

g

ᆠ鼀

k҈ 꾀



\

t҈㦨

m

 = 

 ��㡰

M M  = Þ  Þ M㦨҈├� 黨 M + M +

ᆠ㡰 �鼀ᨨ    鼀�盐 �矄㦨s 矄� �A㦨Aekt

A = Ae e - k ´  A = Ae e- kt  ҈

T m  =p =p = 䰘� 矄ᆠ  k 

�矄 ᆠ  = � 㦨 ᨨᆠ�泐 ҈

m  =p = ҈� 矄ᆠ k҈ ҈

M + k

Topic-4 : Damped, Forced Oscillations and Resonance

ᨨ犨�鼀├ ᨨ ᨨ鼀ᨨᔴ

t㦨 p

 �㡰

�� � �⼄ �㡰泐 ��㡰



ᨨ犨   ᨨᆠ├ 犨� ᆠᨨ鼀矄矄     矄� �    

 矄� ��� � 矄�矄 ᨨ鼀 �  �鼀├ ᔴᨨ꾀

M k M  = p k

㦨 p

҈



k m

␔  鼀矄矄�矄� ᆠ矄 泐├�

k

v

m҈ g k

꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ �  鼀矄矄�矄� ᆠ矄 泐├� �ᨨ � ᆠ矄矄 泐҈ 矄 �鼀 �ᨨ  矄� �

ᨨ

T m  㦨 犨 T㦨p  k

ᨨ  �矄 ᨨᆠ矄矄 �鼀 ├

 ��㡰

T㦨 p

҈ö æ çQ  q = ÷ �ø è

҈R

m g k

꾀 �盐 ⼄盐 ᆠ泐犨  m҈�矄鼀ᨨ ᨨ 泐m�矄 

᲼ᆠᨨ矄 � + q㡰 + ҈�ᆠᨨ矄 � - q㡰桌V rgR T㦨p

ᨨ x҈㦨

 �㡰

ᨨ鼀 ⼄矄 �㡰  ��㡰 鼀�盐  ᨨ ᨨ矄ᆠ��ᨨ

和� ᆠ꾀�矄矄鼀ᨨᨨ 和ᨨ ᨨᆠᆠ�ᨨ ᨨ �ᨨ �

 �矄 ��ᨨ 矄ᨨ 鼀ᨨ�ᨨ  ᨨ鼀 ᔴ ᨨ  ᨨ ᔴ �矄 盐 � ᨨ鼀 犨� 矄 ҈鼀⏌矄

 鼀矄矄 犨� 矄�├   ��  矄� � ᆠᨨ鼀矄矄 �   ⧤쟼 ᨨ   鼀矄矄 犨� ᆠᨨ  � ᨨ 쟼 ᨨ    矄� �꾀��    矄� � 犨�盐 ᨨ�矄 ᨨ鼀矄�  泐ᆠᨨ � ��矄쟼ᨨ⧤쟼 ᨨ  ᨨᆠ├

t㦨

kx㦨mg

I C

V r ´ �R  㡰

㦨p

䰘

 = � ҈



 �㡰  ��㡰

�� � � �㡰泐 ��㡰 矄ᨨ� �犨� t㦨矄 b㡰꾀鼀�盐 ᨨ  ��ᨨ   �鼀  㦨 �矄 ��  泐 꾀㦨꾀 ҈맔㦨҈맔꾀㦨꾀 矄ᨨ㦨�  꾀 =

꾀 

WWW.JEEBOOKS.IN

EBD_8341 PS-152

Physics ҈

҈ Þ =  ҈  

㦨҈ ;䰘矄 b㡰 ᔼ  �矄ᆠᨨ�矄�ᨨ 鼀盐鼀ᨨ鼀 盐鼀犨��鼀 ᨨ矄泐矄鼀 �  矄ᆠᨨ  ᆠᨨ�矄�ᨨ  犨   鼀ᨨ鼀 盐鼀 ᨨ  㝐 졔 鼀㡰 �矄 �  ᨨᨨ矄� �ᆠ�ᨨ 鼀盐鼀ᨨ鼀 盐鼀ᨨ �ᆠ犨�鼀├�矄鼀ᨨ鼀 盐鼀 ᨨ 졠 ҈ ᆠᨨ�矄�ᨨ  鼀 ® 㝐 + ҈ 錐 㝐 + ҈鼀 ® 

E҈㦨

鼀盐 盐 = 鼀盐㦨 㝐졔҈ 鼀㡰 Þ  = 㝐 + ҈鼀 ҈� 㦨w꾀 Þ

盐 = ҈�



�

҈ 䰘� ҈ = ҈� ҈ 

Q 꾀 = 꾀 

 鼀

E㦨

-

 �㡰

-

… ��㡰

꾀㦨䰘黨꾀 \a㦨䰘黨 㡰 r r ᆠ㡰 矄盐 ᨨ  矄矄 a t  � a rᆠᨨ鼀ᨨ  ᨨ

ᔼ 

r

 㡰 ᔼ  和㝐 ᨨᆠ�泐ᨨ  �ᆠ矄 �ᨨ矄 ᨨ  ᆠ矄� � ᨨ鼀 鼀 �鼀盐鼀盐ᨨ ᨨ矄 �ᆠ矄 ᨨ鼀鼀 ᨨ矄��ᨨ

ᨨ  鼀 ᨨ矄��ᨨ 

 ᨨ �    �鼀 ├  ᨨ   ᨨ 泐 ᨨ �ᨨ ᨨ鼀 O ᨨ A⏌�矄T҈ ᨨ�ᨨ ᨨ鼀A⏌ᨨA�矄T  ᨨ�ᨨ盐矄泐T҈T

FL æ YA ö ÞF = ç ÷l 㡰 꾀矄犨├ ᨨ犨 Y = è Lø Al

a a 㦨n  㦨n   ᨨ鼀⼄  㡰 b R

w҈ w҈ E҈  㦨  ´ n 㦨 w E w ҈҈

\

꾀 �盐 ⼄盐 ᆠ泐w㦨

n㦨

K YA ᨨ w = m ml

n ´҈ ´ 黨 ´҈ ҈´҈ 黨

E҈ E 㦨 w҈ w

 㡰 꾀泐� � ᨨ⼄盐 t = I a

æl ö 矄� q÷ + Mg l 矄� q㡰 = I A a A è ø

ᨨᆠ矄꾀 mg ç

l/

YA æ YA ö Kl = ç ÷ l  Þ K㦨 L è Lø

ᨨ ҈ =

 �㡰

 㡰

꾀矄ᨨ 㦨Kl

\

 ���㡰

  ᨨ鼀⼄  �㡰



ᨨ

x R

w 㦨n w҈



黨

Ew

E҈ w҈ a 㦨 E w R 

  ᆠᆠ�ᨨ  �矄 矄  泐 a



p

ᨨ鼀⼄ 矄 �㡰  ���㡰

 ҈�㡰 鼀

ᨨ鼀⼄ 矄 �㡰  ��㡰

 䰘

҈ mw R  

a w 㦨 b w҈

… �㡰

꾀 ҈鼀ᨨ矄ᆠᨨ 

꾀 = 꾀 

 ��㡰

p鼀 㦨mv鼀 㦨mwR R㦨mwR Þ mw㦨҈ ᨨ鼀⼄ 矄 ��㡰  �㡰

犨 꾀 㦨鼀 �鼀盐鼀鼀�盐 㡰 꾀ᆠᆠᨨ � �ᨨ ⼄盐矄�ᨨ 矄  � 矄ᆠᨨ 

黨꾀  = 꾀   鼀

x

a

ᨨ 矄ᆠᨨ  鼀ᨨ �ᆠ ᨨ矄ᆠ�ᨨ 㝐矄矄㦨 m 꾀 �盐 ⼄盐 ᆠ泐㦨w 꾀鼀�盐  㦨 R 㝐 �鼀盐鼀鼀ᨨ鼀 盐鼀p鼀 㦨R

ᨨ �泐㦨E

b㡰  ᆠ  � �  �鼀 �ᨨ ᆠᨨ鼀  ᨨ   盐 鼀 ᨨ矄ᆠ�ᨨ � ᆠ矄矄 泐 奠 ᆠ㡰

b

 �㡰

҈ a 㦨 b mw҈

⧤ ´꾀 㝐 - ҈鼀

-

҈ mw҈ a  

E҈w҈

p鼀 㦨mv鼀 㦨m aw҈ Þb㦨m aw҈

盐� �盐ᨨ 㝐鼀盐 ⧤犨�鼀�盐 

꾀=

p

b 㡰 ᨨ �矄 鼀ᨨ �ᆠ ᨨ矄ᆠ�ᨨ 㝐矄矄㦨 m 꾀 �盐 ⼄盐 ᆠ泐㦨w҈ 꾀鼀�盐  㦨 a

ᨨ �泐㦨E҈ 㝐 �鼀盐鼀鼀ᨨ鼀 盐鼀 p鼀 㦨b

 �㡰

q

l/矄� q l/

mg

l矄� q

-䰘

 Q Y㦨黨맔҈黨�� 㡰 Mg

WWW.JEEBOOKS.IN

PS-153

Oscillations

æl ö ᨨᆠ矄 mg ç 矄� q÷ + Mg l 矄� q㡰 = I B a B  ��㡰 è ø ᨨ鼀⼄ �㡰 ��㡰 IA aA㦨IB aB

҈

҈

҈䰘

҈  at  ᨨᆠᨨ 矄 ᨨ矄��ᆠᆠ�ᨨ ᔼ  �矄ᆠ矄犨 

�ᨨ ᨨ矄� � 犨 s矄盐矄t矄矄 ᨨ犨

泐�  矄㡰 㡰�矄盐 ᨨ盐ᆠ盐矄� a�矄 v�矄ᨨ矄�� R S㦨S 졔vt�  㡰

҈

u  矄� q  Þ R ¥ u g

㡰 T㦨 2π ҈

l g

E҈ = E

b㡰 ␔   ᨨ矄��ᨨ ᨨ  鼀矄矄�矄ᨨ  鼀 �   ᨨ矄��矄�   ᨨ鼀ᨨ矄ᨨ� 㡰 鼀ᨨ鼀 盐鼀�矄 ᨨ꾀矄  鼀矄矄鼀ᨨ矄ᨨ犨 矄 鼀 ᨨ矄��ᨨ  鼀ᨨ鼀 盐鼀� ᆠ矄矄 �   �� �ᆠ�ᨨ  꾀矄   鼀矄矄 �矄 ᨨ矄�ᆠ�� � �  犨 �矄 鼀�盐  犨� �ᨨ ᨨ

ᆠ矄� �  鼀�盐 犨� ᆠ矄犨�  �鼀 ᆠ㡰  �ᆠ 犨� ᨨ  ᨨ鼀 ᨨ矄ᆠ��ᨨ 矄 �  �泐£  ᨨ쟼>ᔼ E㦨V ᨨ � �泐犨� ᆠᨨ鼀ᆠᨨ 矄 矄 �ᆠ �  � �� ᔼ  �矄ᆠ矄矄ᨨ   �ᆠ 犨� ᨨ ᨨ矄ᆠ� \ E>V \ VE> b㡰 ᨨ � �泐V㦨µx��

T  ¥ l

҈黨



F=



Q 꾀矄V x㡰㦨ᆠᨨ 矄  ᨨx>X \ F㦨   ᆠa㦨 ᨨx>X 꾀ᨨ�  鼀矄矄 m �矄矄盐矄        ᨨ   鼀矄矄矄矄 犨� ᨨ  � L �� 㡰 ᨨ鼀 �� 㡰 盐ᨨ⼄盐���盐鼀 T㦨mg �㡰

l

꾀®錐®⼄錐ᔴ®錐®⼄ 꾀㡰 ᨨ  矄�鼀 鼀ᨨ �ᆠ 鼀ᨨ�ᨨ  v 㦨 w a - x



 졠



ᆠᨨ鼀� ��犨� v㦨 c҈ c - x  �矄⼄盐�ᨨ �矄和㝐犨� 犨 㦨c҈ a㦨c 㡰 v㦨kx 犨   x �矄 ᨨ矄��錐 v�矄    矄 x ᆠ矄矄 v ᆠ矄矄

 ᨨ ├� �ᆠ  �泐犨� ᆠ矄 ␔   x 㦨  v 㦨 

 ᨨ ᨨᆠ ᨨ矄 ᨨᆠ  ��矄 �ᆠ�ᨨ  ␔  x�矄 ��v�矄ᨨ矄��盐矄x ᆠ矄矄� 鼀� �盐  v矄ᨨ ᆠ矄矄  ᨨ├� �ᆠ �泐 ᆠ矄矄␔  x㦨 v㦨  ᨨ ᨨᆠ ᨨ矄 ᨨᆠ  ��矄 �ᆠ�ᨨ  ᔴ㡰 ␔  a㦨    矄� �    矄�ᨨ  x   k x㦨mg ␔     ᨨ 矄矄 �ᨨ� � 盐犨 矄 犨�   ᆠᨨ 矄  ᆠᆠ�ᨨ 矄矄 泐 ᨨ矄�  ᨨ ᨨᆠ�矄  矄 \ ma졔mg㦨kxἘ Þ ma㦨k xἘx㡰 和� ᆠa�矄ᆠᨨ 矄 㡰 㡰  ᨨᆠ �矄 ᨨᆠ  犨�   矄  �矄

 ᔼ犨�  ᨨ ᨨᆠ  �  �ᆠ�ᨨ ├矄ᨨ 鼀ᨨ� � 犨�  ᆠ矄� � 矄  㡰 ␔     �矄  ᨨ犨  盐犨 矄    ᨨ�  ᨨ   ᨨ犨 졠㡰   �  鼀ᨨ鼀 盐鼀 �矄 �  盐犨 矄 �ᆠ�ᨨ    矄  鼀 �鼀盐鼀 盐 㡰     ᨨ矄��ᨨ  �矄 ᨨ꾀矄   �鼀 矄矄矄  鼀ᨨ矄盐犨 矄 �矄鼀ᨨ鼀 盐鼀 �ᨨ矄ᨨ  ᆠ矄� �     ᨨ矄��ᨨ  ᆠᨨ鼀矄 ᨨ矄��  鼀ᨨ鼀 盐鼀 ᆠᨨ鼀矄 ᨨ    ᨨ鼀ᨨ矄 ᨨ�  꾀矄   �鼀 � ᆠ矄矄    矄矄 鼀ᨨ� � ᨨ犨  犨�  

� ᆠ矄� �� 鼀ᨨ鼀 盐鼀�   ᨨ犨 犨  �ᆠ�ᨨ  ��㡰  ᆠ 矄 ᆠ├ᨨ�矄ᨨ��� ᨨ矄��ᨨ 

M -

ML T -

L =T

-dV x㡰 dx

T⏌A L l⏌ L YAl Þ T㦨  ��㡰 L

ᨨ鼀

Y㦨





l

x

ᨨ鼀⼄ �㡰  ��㡰 mg㦨

YAl L



鼀�

 ���㡰

�� 㡰

�� 㡰

鼀� �� ᆠ㡰

ᨨ鼀 �� ᆠ㡰 矄ᨨ� � ᨨᆠ

é YA l + x 㡰 YA l ù L L úû ë

㦨᲼T'  mg桌㦨 ê

  �鼀矄  

GM e 矄ᆠ矄 Ve㦨   ᨨ ᨨᆠ犨�  Re

= ᲼ ML-T - 桌

҈ m ҈ = A a L

x

=

MLT -

ᨨ犨

T Þ

ᨨ �  �泐

a=

u



҈

\

\



ᔴ㡰 R㦨

ᔼ 和㝐鼀ᆠ  �ᆠ �泐E µ 鼀�盐 㡰 쟼҈ µ 㡰  쟼 µ 

ᆠ㡰

\

和� ᆠ I A > I B \ a A < a B  ᆠ wAwB 꾀®錐 ®⼄錐  矄錐 ᔴ ®矄錐  ®⼄ 꾀㡰  ᨨ �  �泐 ├ 鼀� �鼀盐鼀  鼀  ᨨ矄��ᨨ   鼀 �鼀盐鼀   鼀 ᨨ矄��ᨨ  ᔼ  ᆠ矄 ᨨ   和㝐 犨 �  ᨨ ᨨ ᨨ �  �泐 矄盐矄 �矄ᆠ鼀  �  㡰和㦨盐 ᨨ㦨  ᨨ犨 �矄�� � 矄矄� �  ᨨ盐�  ᨨ���  S㦨ut졔

҈�

㦨

᲼ ᨨ鼀 ���㡰桌

-YAx L

졠 ᆠᨨ鼀� � �矄⼄盐�ᨨ 犨� F 㦨mwx mw㦨

YA YA p =  Þ w㦨  Þ  L mL T

ᨨ ⼄盐 ᆠ泐 f =

YA mL

҈ ҈ YA = T p mL

WWW.JEEBOOKS.IN

EBD_8341 PS-154

Physics

Waves

14

Topic-1 : Basic of Mechanical Waves Progressive and Stationary Waves ҈



҈ æ gRT ö 錐 C鼀矄㦨 ç C鼀矄µ ÷ è M ø m � é ù ê g mᨨnᨨatᨨm�c =   R  T ᆠᨨ 矄  ú ë û C鼀矄҈ æ m ö \ = ç C è m ÷ø

㡰 꾀矄 犨 ├ ᨨ犨

w ´ rV  V é Bù w êQ K =  V = ú rû V ë DP ҈ ҈  鼀= 鼀鼀 » 鼀鼀 Þ S = »  ҈ rV w ҈ ´  ´ ҈ b㡰 ෌� �矄 ᆠ犨 ᨨ ᆠ矄 ᨨ ᨨ盐� 㦨҈�鼀 l = n҈ + ҈㡰  �矄 ᆠ犨 犨ᨨᆠ矄矄㦨�鼀 = n l ҈� n҈ + ҈㡰 = Þ n = ҈n҈ + � �  n n҈ n� � ᔼ n҈ = ҈ n = � \l = ҈ n҈ =  n = ҈� \l = ҈⏌  n҈ = 䰘 n = � \l = ҈⏌ � ҈ ҈ ҈  ᆠᨨ矄矄�犨 � 矄    鼀 ҈  � b㡰 꾀t㦨x㦨y㦨 f㦨p 㡰 矄� �b㦨҈ 矄矄盐 鼀�盐  DP = aKB = S KB = S ´



 

�



䰘

æ I ö ᨨ҈㦨҈ ᨨ�҈ ç -҈ ÷  �㡰 è ҈ ø  P = 꾀矄ᨨI㦨  ��㡰 pr  pr  졠 矄ᨨ� �ᨨ⼄盐�ᨨ 矄犨� r㦨ᆠ鼀 㡰 ᔴᨨ鼀� � �� ⼄盐�ᨨ

泐㦨҈矄� �졔 㡰犨� 矄  ⼄盐�ᨨ  泐㦨矄� w├ 㡰 Þ 犨�矄鼀ᨨ� �ᨨ � 㜠 �矄犨� 矄 w � = � 鼀⏌矄ᆠ  = Þ= ⧤  㡰 ෌� 鼀�盐 㦨҈ᆠ鼀 犨ᨨᆠ�泐㦨 맔鼀 �鼀盐鼀 �ᆠᨨᆠ�泐 � wl =  w p p ᨨ l㦨㦨맔҈㦨ᆠ鼀 㡰 �ᆠ ᨨᆠ�泐 vp �矄   ᨨ   �矄ᆠ鼀  ᨨ    �ᆠ ᨨ鼀   鼀  ᨨ矄��ᨨ  矄 泐 v p = pv A  y   ævö v p = p ç ÷ A   y   èlø

p ˆ p    鼀⏌矄 ´ ҈ ( ҈)  ( �) = � � 和� ᆠ 犨�矄矄� 盐矄ᨨ� 鼀ᨨ� �� ᨨ矄�� 㜠 �矄 ᨨ� 犨� 鼀ᨨᨨ泐㜠 �矄  ᨨᨨ�ᨨ 矄 ᆠ㡰  㡰盐 ᨨ盐꾀矄   犨鼀ᨨ矄 ᨨ犨 �  ᨨ矄��㜠 �ᆠ�ᨨ    ᨨ�  矄 ᨨ盐 鼀ᨨ盐犨 矄��   ᨨ矄��Ӹ㜠 �ᆠ�ᨨ 

㦨

b㡰 和 ᨨ 矄ᨨ盐 � �矄

鼀矄 

黨

҈

҈

dy = - Aw ᆠᨨ矄 kx - w t 㡰 \ v鼀 㦨Aw 㡰 v 㦨 dt 㝐 �鼀盐鼀�ᆠ ᨨᆠ�泐ᨨ  �ᆠ� 和㝐v鼀  㦨 Aw xù é b㡰 y㦨y矄� p ê f t - ú lû ë \ ᨨ

dy é x öù æ = y ᆠᨨ矄  p ç f t - ÷ ú ´ pf dt êë l øû è é dy ù = y ´ pf êë dt úû 鼀

෌� 㝐 �鼀盐鼀 �ᆠᨨᆠ�泐㦨c㦨 f맔T㡰 \

y맔pf㦨 f맔l㡰

l㦨

p y 

҈

҈҈

෌�  y =

҈

꾀t㦨犨�y㦨҈犨  x㦨 ҈ 꾀��  y =  ҈ + ( x - ҈) 和ᨨt㦨y㦨҈犨  x㦨҈

犨盐矄 矄  �矄 ᆠᨨ ҈鼀� 矄ᆠ ҈ -҈ \ ᨨᆠ�泐ᨨ 犨盐矄 v㦨 = � 鼀矄  �ᆠᨨᆠ�泐鼀�盐 㦨鼀 㦨Aw㦨Apn �ᆠᆠᆠ�ᨨ 鼀�盐 㦨a鼀  㦨Aw 㦨pnA v ҈ T  㡰 ␔ � ᨨ 盐矄 l = = ᨨ  µ

f f m ␔  㦨 矄�ᨨ ᨨ 矄� �  ҈>  \ l҈>l

ᨨᆠ��矄ᨨ  犨ᨨ盐矄矄ᆠ

ᨨ矄鼀鼀� 㜠ᨨ� 矄 ᨨᆠ�泐 � � ᆠᨨ ⼄盐 �泐 矄 �ᆠ�ᨨ 

҈

(҈ + x) 

T 矄ᨨ矄  泐ᨨ矄��ᨨ 犨�矄鼀 ᨨᨨ 盐矄矄 m   ᨨ�鼀├ 泐ᨨ 盐矄矄犨�矄鼀� 꾀졠㦨 졠꾀 ᆠ 㡰 ᨨ 犨�  矄�泐� �泐ᆠᨨ矄矄� �盐 � 盐 � �鼀�矄ᆠᨨ 矄 ᨨ� 矄 盐 ᨨ  矄 �ᆠ 犨 �  矄�泐  �矄 ᆠ  ᨨ鼀  ᨨ�  矄ᨨ盐ᆠ ҈ Iµ  r 盐  ᨨ�  矄�y ᨨ    矄 �ᆠ 犨ᨨ   矄 �ᆠ 矄盐 ᆠᆠ   矄ᨨ盐ᆠ鼀� 矄ᆠᨨ 矄 �鼀矄 㦨

҈

ᨨ� 矄ᨨ盐ᆠIµ

҈ 矄 �ᆠ犨�矄 ᨨᨨ 盐ᆠ 泐 �  r

矄ᨨ盐ᆠ

WWW.JEEBOOKS.IN

PS-155

Waves ҈� ҈

bᆠ 㡰ᔼ  犨鼀ᨨ�ᨨ  y = a ( kx - wt )  yᆠ 矄  ᆠ�ᆠ   鼀� �ᆠ � 矄 �  ᆠᨨ鼀� �ᆠ 犨矄  �矄ᆠ鼀    矄矄盐 �  矄ᨨ盐  犨矄 bᆠ 㡰ᔴᨨ鼀� � �� ⼄盐�ᨨ y xt㡰   㦨 =   + �㡰  + � � ù é ҈ ê +  ú + �  û ë ␔�  ⼄盐�ᨨ ᨨ 鼀ᨨ� �盐矄 y㦨f x졔t㡰 � -҈ � -҈ 鼀矄 㦨 鼀矄 =   泐 和ᨨ 犨犨� �矄 ᆠ ҈鼀 ᨨ �鼀� 矄ᆠ

҈䰘

҈

(  x + �t ) + �  = = ҈ 鼀 졠  � \㝐 �鼀盐鼀 �矄ᆠ鼀 �矄҈鼀

矄 ᨨ  盐矄x㦨 t㦨�矄矄矄 ᨨ犨 �  ��盐 � �矄 矄泐鼀鼀�ᆠ ᆠ㡰 ᨨ   矄矄 矄� 盐矄ᨨ � 犨 � � ᨨ   矄� �  鼀 �鼀盐鼀ᨨᆠ�泐v鼀 㦨aw

\l = 

҈

҈ -

=





= v

v҈ = v

T҈ v Þ ´= T v

(Q V µ T )  ´ ҈ T



 ´ ҈ = �҈� ´ ҈ N  Þ T㦨�҈�맔҈N 㡰 ෌� l㦨ᆠ鼀m㦨�A㦨҈鼀鼀v㦨黨鼀⏌矄 Y㦨 ҈맔҈҈҈鼀 Þ T =

�

¶ y

f ( x t ) = f ( x + l  t )  ���㡰 bᆠ 㡰෌�  y㦨҈矄�  t졔x㡰 ᔴᨨ鼀� � �� ⼄盐�ᨨ 犨�  矄  犨⼄盐�ᨨ

y㦨a矄�  wt졔k x㡰 꾀鼀�盐 a㦨҈鼀錐k㦨鼀҈  꾀 w㦨 ⏌矄Þpf㦨 \ f㦨  p p p = l = 㦨p 鼀  k w  和 ᨨ 犨㦨 = 㦨鼀⏌矄 k 

f x � Tx T 黨 = = \ x = = � f z  Tz Tz  b㡰  ᨨᆠ�泐 ᨨ    矄矄 犨 �   矄ᆠ   犨� �矄 ��  泐

\

 �㡰 ¶t  ¶x 

 犨 鼀ᨨ�ᨨ  �矄 ᆠ ᆠ�   泐  犨ᨨ ᆠᨨ ��ᨨ 矄 f ( x t ) = f ( x t + T )  ��㡰



҈ Tx ҈ Tz   f z = l m l m

T m ␔  T㦨  矄�ᨨ �  犨� m㦨 �   矄�泐ᨨ 犨�

҈ ҈�p ҈ ´ 㦨҈�鼀⏌矄 Þ l㦨 㦨鼀 㦨 p � �

¶ y

T҈ ├�

v=

p p  = ҈p = ҈�p   l l

ᨨ

l㦨ᆠ鼀

g l҈ = l҈ = ҈ ᆠ鼀 T҈㦨� ᨨᨨ鼀㡰 g ҈ T  㡰 矄� � f = l m 鼀矄矄 犨 T㦨 矄�ᨨ   m =  � fx =

҈  p

ᆠ㡰 ᨨ 犨 鼀ᨨ�ᨨ    �  � ⼄盐�ᨨ  �矄 ¶ y æ w ö ¶ y é wù = ç ᆠᨨ 矄   ÷   êQ v = k ú ¶t k ¶ x è ø ë û

T T l  =  l҈ M T҈

V = l

҈鼀├�

 =



p ´ ҈  ҈ = p ´ ҈ - 鼀 꾀  l㦨 =  n ҈ ⏌ p bᆠ㡰෌� ⼄盐�ᨨ y㦨A矄�  ҈px졔҈�pt졔p⏌㡰 ᔴᨨ鼀� �  �矄 ⼄盐�ᨨ  犨�   矄   ⼄盐�ᨨ  ᨨ   犨 � �� X �ᆠ�ᨨ

T

T㦨� ᨨ㡰

p é p  ù é p ù t+ x + fú y㦨A矄�  ê t + x㡰 + f㡰 ú Þ y㦨A矄�  ê l l l ë û ë û

҈黨

ᆠ㡰 矄� � V = f l

n=



 ҈ = = ҈鼀⏌矄 ҈ ҈ aw㦨҈ Þ ҈맔2pn㦨҈᲼Q w㦨pv桌

Þ n㦨

 ҈҈ ´ ҈ ´ ҈ = =   ҈� �

V҈ V V = Þ l  =  l҈ l҈ l  V҈ 꾀�� 盐矄� �

෌� 鼀 �鼀盐鼀ᨨᆠ�泐㦨 \

㡰 l҈㦨҈䰘ᆠ鼀 l㦨�ᆠ鼀V㦨鼀⏌矄f㦨䁸 l =  l - l҈ 㡰 =  ´ � - ҈䰘㡰 = ҈� ᆠ鼀 ᨨ犨 ᨨ鼀 v = f l Þ  = l ´ ҈� ´ ҈-

㦨



꾀 x =  t =  y =

Topic-2 : Vibration of String and Organ Pipe

矄� � v =

T mv  ´l ÞT = m I

T DL ⏌ L A Tl mv  ´ l  ´ ҈ ´ 黨  DL = = = =  ´ ҈  m YA l Ӹ꾀㡰 ҈ ´ ҈҈҈ ´ ҈  㦨鼀鼀

꾀��  ᨨ鼀 Y =



b㡰 ␔矄   㦨

m

犨  ᆠ�矄矄㦨

\  =

㝐� m

和�鼀�泐犨   ᆠ�矄鼀ᨨ� �犨�  ᆠᆠ�ᨨ 

WWW.JEEBOOKS.IN

EBD_8341 PS-156

Physics

(

㝐 � 졔   � 㦨

)

鼀 ´ ´�  ��㡰 l ᨨ鼀 ҈㡰  㡰 = � l 

҈

m

Þ � = 

  矄�ᨨ =

� 졔  �



� 졔    æ � ö  㦨҈졔 Þ �  졔   㦨 � 졔 �  맔 çè ҈졔 ÷ø 㦨     �  �  㦨� 㦨 ᲼犨 �ᆠ �矄ᆠᨨ矄矄ᨨ�⏌�桌   䰘

b㡰

-҈⏌ = � 

黨

҈

҈

꾀 l =  Þ l =   l 㦨҈鼀 Q 㦨ᆠ鼀㦨鼀 �� 㡰 矄� �㦨 l

 l⏌

҈�



Þ f =

҈

=

犨  m =

T mù  m = ú lû m

Tl T Y Dl Þ = ADl A l

҈ l

y Dl lr

 �㡰

盐� � 盐ᨨ  l

Dl  r  y� ⼄  �㡰犨� l

 ҈ ´ 䰘  ᨨ f » ҈䰘 㡰 ᨨ � ᨨ  犨�㦨҈҈ᆠ鼀

҈  㦨҈ ҈   � 矄ᨨ   矄 f =

҈ Qr㦨 r҈

꾀矄 µ

҈ 

҈ ҈ ҈   = ҈    ҈  

\

҈㦨

\

æ ҈ ö ҈ = ç ´ ҈҈÷ = 䰘 ᆠ鼀 è ҈ +  +  ø

 �㡰

鼀 鼀矄矄 ᨨ 矄� � =   � ᨨ 矄� �

é êQ v = ë

Dl 㦨҈ l  r 㦨䰘䰘맔҈ ├�⏌鼀 �� 㡰 y㦨맔҈҈҈⏌鼀 �� 㡰

㡰 ␔├ ᨨ犨  ᨨᆠ�泐�  矄� ��矄 ��  泐

m

T Ar

l 㦨҈�鼀



l p  r 꾀矄  l矄鼀 ᨨᨨ  犨�矄

҈㦨  ҈ ҈ =  

v ҈ T ҈ = = l l m l

꾀矄ᨨ Y =

=

 Þ

 l

 盐 鼀  ⼄盐 ᆠ泐� ᆠ矄 㡰�矄   = = f '㦨  l ⏌ 㡰 l ᆠ㡰  � ᨨ �㦨�ᆠ鼀㦨�鼀 ⼄盐 ᆠ泐ᨨ  ᨨ矄ᆠ��ᨨ 矄 ᨨ  �ᆠᨨ盐鼀  �  ᆠᨨ矄  ᨨ�  � �矄 ��  泐 n - ҈㡰u n - ҈㡰u f = £ ҈� Þ f = L L  - ҈㡰 ´  £ ҈� Þn҈҈�» Þ � ´  b㡰 盐 鼀  ⼄盐 ᆠ泐

f =

 �� ´ ҈ Þ = = l ҈ 㦨맔҈  ; �⧤ b㡰 ҈㦨 

®和鼀 ®和鼀 l®和鼀 ⼄盐 ᆠ泐ᨨ  ��ᨨ

҈  =  r҈ r

㡰

 盐 鼀  ⼄盐 ᆠ泐� ᆠ矄 㡰�矄 =

҈

Ӹ 黨䰘 ´ ҈҈ = r 䰘 ´ ҈ 㦨��맔҈鼀⏌矄ᆠ 和� ᆠ ᨨ  �矄 ᆠ鼀   鼀�  盐 鼀  犨 矄 �矄 矄 ᨨᨨ犨

l 㡰

(  - ҈)  =

=

(  - ҈) ҈ l 犨  ҈㦨 盐 鼀  ⼄盐 ᆠ泐ᨨ ��ᨨ 㡰  ᆠ㦨 ҈㡰맔҈� Þ 㦨䰘҈»䰘 \ 盐鼀ᨨ ᨨᨨ 矄㦨 ᨨᨨ 鼀ᨨ ᨨ ��ᨨ 㡰҈ 㦨䰘҈㦨 㡰 ᔼ  矄ᨨ� 矄 ᨨᆠ�泐ᨨ  犨

 l = =  � ҈

f

b㡰 l

l VA u r = B = B =  = A Þ l = l Þ P = ҈ A B lB VB u A rA q  㡰 ᔼ   ᆠᨨ矄  � ��ᨨ  �    鼀ᨨ     ⼄盐 ᆠ泐 ᨨ

=

҈҈



= �´ \  = 

 =  鼀⏌矄ᆠ 

 =    ᆠ㡰 꾀矄 鼀盐矄 ᨨ ᨨ  矄  ᨨ� ᨨ   犨�A B矄ᨨ

��ᨨ 





Þ 

꾀矄ᨨ f҈ = 

l

\ ò -҈⏌ - � ò 

l  =  ᨨl = m  

ᨨᆠ�泐v㦨 f l =  ´



l

WWW.JEEBOOKS.IN

PS-157

Waves æ  ö  = ç ´ ҈҈÷ =  ᆠ鼀 è ҈黨 ø

҈䰘

҈

҈

æ  ö   = ç ´ ҈҈÷ = ҈ ᆠ鼀 è ҈黨 ø  ᆠ � �矄矄 ᨨ盐 ᆠ 䰘ᆠ鼀 䰘졔㦨黨 ᆠ鼀 ᨨ鼀ᨨ   b㡰 ᔴᨨ 矄� � �     ᆠᨨᆠ�ᨨ  ᲼e 㦨  D 犨  㦨 �鼀桌 é v ù f = n ê  l + e ú ᨨ �矄矄ᨨ  ᆠn㦨҈ )û ë ( v v \f㦨  ( l + D ) Þ l =  f  D æ  ´ ҈ ö ᨨ l = ç ÷   ´  = ҈�ᆠ鼀 è  ´ �҈ ø 㡰 ⼄盐 ᆠ泐 ᨨ    鼀ᨨ �ᆠ ᨨ  矄� � 㦨 盐 鼀  ⼄盐 ᆠ泐ᨨ 盐ᆠ  �    �

㡰 ⼄盐 ᆠ泐ᨨ    鼀ᨨ �ᆠ ᨨ  ᨨ  � v v f҈㦨 = l l ⼄盐 ᆠ泐ᨨ    鼀ᨨ �ᆠ ᨨ  ᆠᨨ矄  �

v nv = l l n�矄ᨨ  盐鼀 ᨨ鼀⼄ �㡰  ��㡰

 ��㡰

f㦨

f㦨

 �㡰

n f҈  ᨨ �矄矄ᨨ  ᆠn㦨�  � f҈  ᔼ 矄ᨨ  ᆠ盐

\f㦨 

ᆠ㡰

 l҈ 졔

l 졔

�鼀

ᨨ �矄矄ᨨ  ᆠ

l l҈ + e =  盐 㦨nl  \ 㦨n l  + e㡰 

鼀

æv ö v ç ҈ ÷ =  è l҈ ø Al é ҈ Tù v \ ´ê ú= ë l҈ m û l

҈黨



҈ �  \ = Þ m㦨├�鼀҈ � m  ´   ᆠ 鼀矄矄ᨨ  矄� �m҈㦨ml҈ 㦨맔�├�㦨҈� 㡰 ᨨ 鼀�  矄 ᨨ 矄ᨨ盐 盐矄� �矄ᨨ  ᆠᆠᨨ盐鼀 ᨨ �矄 ᨨ  盐 � � ᨨ├├� �ᆠ  꾀矄矄 ᨨ犨  �    ��盐  � �矄ᨨ  盐 � � ᨨ├├�  �ᆠ  

㡰

⼄盐 ᆠ泐ᨨ  �矄 鼀ᨨ �ᆠ� 꾀㦨f҈㦨

⼄盐 ᆠ泐ᨨ 矄ᆠᨨ  鼀ᨨ �ᆠ� ᔴ㦨f

㦨n l҈ 졔e㡰

\

l + e =



l 

 v  l҈ + e = n

Þ l + e =

 �㡰

Þ

 ��㡰

和盐ᆠ� � �㡰  ��㡰

 = n l  - l҈ 㡰  \ D㦨n Dl  + Dl҈ 㡰 㦨맔�҈맔 ҈졔҈㡰ᆠ鼀⏌矄㦨ᆠ鼀⏌矄  ᆠ鼀 �鼀盐鼀ᨨ矄矄�ᨨ� 矄 Dv㦨ᆠ鼀⏌矄 b㡰 ⼄盐 ᆠ泐ᨨ  �矄 ᨨᨨ  �  ᆠᨨ矄  ᨨ�  �

v P  l҈ r҈ ⼄盐 ᆠ泐ᨨ  �矄 ᨨᨨ  �  ᨨ  ᨨ�  �

n㦨

҈ P l  r v㦨vἘ nἘ㦨

҈ T l m

v P ҈ = l҈ r҈ l

҈ T l m

f҈㦨f �� 㡰

҈ T҈ ҈ T = l m l m ᨨ ҈㦨   �㡰 쟼⼄盐� � ᨨ⼄盐矄 盐 ᨨ T ҈    T   ᨨ盐 O ᨨ ᨨ�ᨨ  ⼄盐���盐鼀 꾀 \T҈x㦨T Lx㡰 ᨨ  矄�ᨨ  ⼄盐���盐鼀 T҈졔T㦨鼀�



҈ ᨨ鼀� �㡰  ���㡰 mg mg 졠 T҈㦨   㦨   � � 㜠 ᨨ犨 ᨨ鼀⼄ ��㡰 \

mg L mg ´x= ( L  x) Þ  x = L  x \ x =  � � �

ᨨ矄ᆠᨨ 矄ᨨ  ᆠ



P r

r  l҈ ҈ r 

\

l =

㡰

盐 鼀  ⼄盐 ᆠ泐f =

P T l m

� 黨g  Mg = Þ M㦨�├� l Ҙ l Ҙ 꾀矄 ⼄ 盐 ᆠ泐 �矄 ᆠᨨ矄ᨨ 矄 ᨨ �        鼀ᨨ �ᆠ P㦨� P㦨矄ᆠ�泐 ҈ æ T ö ҈ æ T ö 㡰 n҈㦨 ç ÷  n㦨 l ç  ÷ l è pr rø è pr rø 㦨

�

n㦨



\

v ҈ = l l

T l ᲼犨  㦨 � ᨨ 矄� �桌 m 

҈ n҈ = ´ =҈ n 

é ù 鼀矄矄 r ´ A ´  � = r Aú êQ m =  � =  � ë û

WWW.JEEBOOKS.IN

EBD_8341 PS-158



Physics

㡰 ᨨbᨨh ᨨ ᨨ� � 盐 鼀  ⼄盐 ᆠ泐

ᨨ ᨨ  ᨨ�  � l

c  �㡰 l ᨨᨨ  ᆠᨨ矄 ᨨ� � ᨨ �  鼀ᨨ �ᆠ ⼄盐 ᆠ泐 æ cö n㦨 çè ÷ø  ��㡰 l  ���㡰 ෌� nn҈㦨҈ ᨨ鼀⼄ �㡰  ��㡰  n ⏌   = =  Þ v҈ = v   �㡰  n҈ ҈⏌   꾀�� 矄ᨨ� �⼄ ���㡰 �㡰犨�n҈㦨  ᆠ㡰 ᔴᨨ鼀� �   ��  ⼄盐�ᨨ  y x t㡰 㦨  ᆠᨨ矄

n2㦨

n҈ =

䰘



pö æ çè �pt + ÷ø ᆠᨨ矄 ҈px㡰  y xt㡰㦨Aᆠᨨ矄 wt졔p⏌㡰ᆠᨨ矄k x ᔼ k x㦨p⏌ ᨨ ᨨᆠᆠ盐矄錐 \ ҈p x㦨p⏌Þ x㦨�鼀 ᔼ k x㦨p  � ᨨ ᨨᆠᆠ盐矄 Þ ҈px㦨pÞ x㦨҈鼀 꾀矄ᨨ 矄  ᨨ  犨 w �p = � 鼀⏌矄  l㦨p⏌k㦨p⏌҈p㦨鼀 v㦨 = k ҈p 㡰 In a�rT㦨鼀�㦨rVg T ҈ rVg = \ f㦨  �㡰 m l m 犨   ᨨᆠ�矄  �鼀鼀矄 � 犨 T㦨 mg盐 盐矄 V Vg 㦨Vrg rw g = r - rw 㡰   Vg r - rw 㡰 ҈ ҈ Vgr r - rw 㡰  \ f Ἐ㦨 㦨 l m l m r r - rw fἘ æ r - rw ö =  f Ἐ = f ç f r è r ø÷

l

Q 



҈

  n1㦨  ᨨ �矄 鼀ᨨ �ᆠ l҈ l1

  l ҈ =  Þ  ҈ = l҈ l  l  ᨨ盐ᆠᨨ矄 

n҈ = n \

\ l = l

lἘ = l 盐 鼀  鼀ᨨ 㡰  c c \ n㦨 = = �҈  l l  nἘ㦨 

\ l Ἐ = l �� 㡰

c c æ cö = =  ç ÷ 㦨맔�҈㦨҈  è l ø l Ἐ l

ᨨ ᆠᨨ矄 ᨨ�  � æ vö f = n ç ÷ 犨 n = ҈� è ҈ø \ l =

nv f

ᨨn㦨҈ l҈ =

(҈)( )

´ ҈ ᆠ鼀 = ҈� ᆠ鼀  ´  ᨨn㦨 l = l҈ = 黨䰘� ᆠ鼀 

ᨨn㦨� l� = �l҈ = ҈�� ᆠ鼀 �㡰  �矄 ᆠ 犨  犨ᨨ 矄盐ᆠᆠ矄矄� ᨨ 矄

� ´  T ⏌m v l = = D㦨 =  f f �

҈⏌ 

黨

2

l = l 盐 鼀 鼀ᨨ 㡰  ᨨ ᨨ  盐

҈⏌ 

é r - ҈ ù 㦨  ê ú  ë r û ᆠ㡰 和�ᨨ 泐犨 �矄 ᨨ 盐ᆠ  犨   犨ᨨ 犨矄  �

ᨨᨨ矄� �ᆠ�ᨨ  ᨨ犨y㦨aᆠᨨ矄 k xwt㡰aᆠᨨ矄 k x졔wt㡰 \ y㦨a矄� kx矄� wt�矄⼄盐�ᨨ ᨨ  矄�ᨨ 泐犨犨 �ᆠ ��矄 ᨨ x㦨 y㦨aᆠᨨ矄 kx wt㡰ᆠ

ᨨ矄 � �ᆠ�ᨨ 矄 ᨨᨨᨨ矄� l ᆠ㡰 ␔  盐犨矄ᨨ ᨨ  矄   = l  v v \ f㦨 = l l lἘ l 犨  盐�矄   � � 犨   = Þ lἘ㦨 l   v v = f \fἘ㦨 = l Ἐ l ᆠ㡰 ᨨ ᆠᨨ矄 ᨨ�  �

㡰

  ᨨ �  鼀ᨨ �ᆠ l 

҈   ´ ҈

=

҈ = �ᆠ鼀 

�㡰 ෌�   �矄泐ᨨ 犨� s = 黨 ´ ҈ - ├�ᆠ鼀 Ӹᨨ盐 �Ἐ矄鼀ᨨ 盐盐矄ᨨ 犨�Y㦨黨맔҈҈鼀 和� 㦨黨맔҈ 和矄矄 T ⏌ A Y= = 和� 和�

T \ = Y ´ 和� 㦨黨맔҈黨맔黨맔҈ A 꾀矄ᨨ鼀矄矄ᨨ 犨� m = Al s m 㝐矄矄盐 � �  m = = As J 盐 鼀  ⼄盐 ᆠ泐�  矄� �

f =  =

҈ T ҈ T = l m l sA ҈ 黨 ´ ҈黨 ´ 黨 ´ ҈ -  ´҈ 黨 ´ ҈

҈ ҈ 黨 ´ ҈黨 -  - = ´ 䰘 = �    ᨨ㡰 l҈㦨 � �� �  ᨨ � l㦨 犨 �  ᨨ �  㦨和 ᨨ 盐 � � ᨨ├  =



ᔼ  ᆠᨨ矄 ᨨ�  � =

 l҈

WWW.JEEBOOKS.IN

PS-159

Waves æ  ␔  盐 � � ᨨ├�矄鼀ᨨ  Ἐ = = ç è  - 

Þ

 æ  ö  ç ÷= l҈ è  -  ø l 

Þ

w 㦨҈鼀矄҈ ├  ᆠ ᨨ�ᨨ 矄 㡰 ᆠ㡰  㡰 矄�矄 泐  ᨨ ᆠᨨ ��ᨨ 矄  bᆠ㡰 泐㦨᲼҈矄�   㡰桌ᆠᨨ矄 㡰᲼෌� 桌

ö  ÷= ø l 

和 ᨨ 犨 v =

 -  l  =  l҈



 - 

-

l l -l -҈ = -҈ Þ  ҈ =   l҈ l҈ ᆠ �ᆠ  �⼄盐� �   � ᨨ  � l  - l҈ - ´ ҈ = ´ ҈ = -�奠  l҈  ᆠ矄鼀矄盐ᨨ ᆠ �ᆠ  �⼄盐� �   � ᨨ ��矄�奠 ᔼ  ��盐 㡰ᨨ  矄ᨨ  盐 � � Þ

䰘



l = l  Þ l㦨 l  c c \f㦨 = l l ᔼ  ��盐 㡰犨    ᨨ   盐 �ᆠ泐 �  �

l 犨 lἘ l = Þ l Ἐ = l   c c = f \ fἘ㦨 = (a) l Ἐ l ҈ T 盐 鼀  ⼄盐 ᆠ泐f㦨 ᨨfµ T l m

 l/2



(b)

f µ 犨�� ᨨ 鼀矄矄 ( w ) f Ἐ µ 犨盐 盐矄 ( F )

u ( x y ) =   x = L y = L [Q 矄� p =  矄� p = ]

fἘ wF w F = ᨨ f Ἐ = f f w w 和盐矄�盐� � 盐矄犨� \

f Ἐ =  黨



( �䰘) g - ( 䰘�) (҈ ) g ( �䰘) g

졠�ᨨ  㡰  u ( x y ) =   y =  y = L [Q 矄�  =  矄� p =  ] u ( x y ) ¹   x =  x = L [Q ᆠᨨ矄  = ҈ ᆠᨨ矄  p = ҈]

=  Hz

和 ᨨ矄 �矄 ᆠ ᨨ鼀   犨  犨 �ᆠ  � �ᆠ矄  � = ҈�鼀 鼀 �鼀盐鼀鼀�盐 ᨨ ��ᨨ 㦨l⏌㦨  c  = � 鼀 Q c㦨vl \l㦨 = v  bᆠ㡰꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ   � ᨨ  �ᆠᨨ盐鼀 �矄 �  泐 ᆠ  �� �    ᨨ  犨 �    矄ᨨ  ᆠ 盐 l 矄ᨨ n졔҈㡰 㦨�䰘졔e  �㡰  l   n졔㡰 㦨黨졔e  ��㡰  �� � �⼄ �㡰泐 ��㡰 ᔼ n㦨҈ Þ \

l ⏌  �䰘 + e = �l ⏌  黨 + e

e㦨҈

p p = ҈鼀 㦨\ l =  l l ҈ = � 鼀  � ᨨ 矄� �l㦨� ´ = � ´  

 鼀� ᨨ�  㝐 �矄    � ᨨ    矄   鼀 �鼀盐鼀 �矄ᆠ鼀 㦨҈鼀  ω⏌├

 盐 鼀  ⼄盐 ᆠ泐v㦨 = l l  = =   ´ � ´  bᆠ㡰 和 � � 犨矄  ᨨ 盐ᆠ 泐 犨ᨨ�  �ᆠ 犨矄 矄盐ᨨ矄� � 犨 � � � �  ᨨᨨ矄� �ᆠ�ᨨ  bᆠ㡰  �矄ᨨ   y ᆠ鼀  矄ᨨ �矄 �矄ᆠ鼀 矄 ᨨ �   x   泐  矄 犨� Q L L㡰 R  L㡰 � �� 盐泐  ᨨ     �矄 졠�ᨨ  㡰  u ( x y ) =  x =L y =L P x u ( x y ) ¹   x = y = 㡰 L㡰 졠�ᨨ  㡰  u ( x y ) =   x =  y =  [Q 矄�  = ] u ( x y ) =   x = L y = L [Q 矄� p = ] 졠�ᨨ  ᆠ㡰  u ( x y ) =   x =  y =  [Q 矄�  =  ] ᨨ鼀 �� ⼄盐�ᨨ ├㦨

�



æ vö b 㡰 ᨨᆠᨨ矄 ᨨ� �v㦨n ç ÷ 犨  㦨҈�䰘 è l ø v v �v \ n㦨    㦨 l l l ҈

ᆠ㡰 ⼄盐 ᆠ泐 n =  ᨨ �矄 鼀ᨨ ᨨ ��ᨨ

l 鼀 ᨨ�nᨨ鼀 �鼀盐鼀�l矄 ᨨ盐 鼀� �鼀盐鼀 和� �㜠҈  =

҈ 

 m

和� �㜠  =

҈ 

 =  m 

和� �㜠  =

҈ 

 =  m 

和� �㜠  =

҈ 

  = m 

\맔黨졔e㦨�맔�䰘졔�e

l 㦨�䰘졔黨㦨�҈ 

\e㦨黨ᆠ鼀 Þ l㦨ᆠ鼀㦨鼀

꾀矄ᨨ矄 ᨨ 矄ᨨ盐 㦨vl㦨�맔鼀矄҈㦨鼀矄҈ ҈ ᆠ 㡰

矄 ᨨ盐  �矄ᆠ鼀  ᨨ x㦨  �矄ᆠ鼀   � ᨨ x㦨鼀  ᨨy㦨x㦨  y = ± A x㦨鼀

䰘

b㡰꾀矄 n =

n l  鼀 

\ = l 鼀 

 m 和� �㜠҈  = l

WWW.JEEBOOKS.IN

EBD_8341 PS-160

Physics ҈ ҈     dE㦨 dm㡰 A w = µdx 㡰 a 矄� k x 㡰  pn㡰   㦨pҘna矄� kxdx Q 㦨nl   T ⏌Ҙ éQ  = T ⏌ m ù \ n㦨 Þ n㦨  =  ë û l l l



和� �㜠  =

æö   ç ÷  ( m ) èø

( )



=  



æ�ö   ç ÷  ( m )  è ø 和� �㜠  = =  ҈ �

\



和� �㜠  = 

æ䰘ö   ç ÷  ( m ) èø

(҈)

\

=  ҈

l

 E㦨 ò dE = ò p Ҙ   

꾀㜠錐 㜠矄錐ᔴ㜠⼄矄錐 㜠⼄ 꾀㡰�ᆠᨨ矄 ᨨ  ␔矄ᨨ 盐ᆠ  ᨨ ��盐 � 

= L 



�҈



lf 

\ l 㦨 㡰 �ᨨ bᨨh 矄 犨矄ᨨ 盐ᆠ  ᨨ ��盐 � 

L

lf

�

= L 



\ l 㦨

lf 

黨

vA  = ᨨr ᨨ vB 

= L 



lf

\ l 㦨  㡰 和ᆠh 犨ᆠ鼀 bᨨh 矄 鼀� ᨨ�  ␔矄ᨨ 盐ᆠ   矄矄 �  盐

ᨨ

l 㦨

æ � ⏌  ö æ ҈ ö ÷ç ÷ 㦨 çè 䰘 ⏌ �ø è 黨 ø

lf

黨 aw =  Þ w㦨 ⏌矄  �㡰  aw 和盐矄�盐� � 盐ᨨ w� ⼄ �㡰犨�  = ҈鼀 a㦨  㡰  p p w   = = = = ᨨ犨k㦨  �㡰  ⏌ n    l ᨨ犨盐� � 盐ᨨ a w k犨�犨 ᨨ鼀  y㦨҈矄� ᲼t᠀ x᠀f桌 

 矄� � �矄 �  盐 鼀  鼀ᨨ    ᨨ l =

p p p = 㦨 l l l 꾀鼀�盐 ᨨ ��ᨨ  �矄 ᆠx ᨨ鼀x㦨A㦨a矄� kx 㝐ᆠ  �ᆠ �泐xᨨ  � dx�矄 ᨨl㦨 l 和� ᆠk㦨

gA gB

g A RTA lB g B RTB MB

=

 

(Q l A = lB )

MB  M g æ ҈ ö = ( 矄TA = TB ) Þ A = A ç ÷ MA  MB gB è 黨 ø

� 䰘ö æ çè g A =  g B = ÷ø  �

M A æ � ö æ ҈ ö  =ç ÷ç ÷ = M B è ҈ ø è 黨 ø ҈黨 㡰 �ᨨᨨ  盐 鼀  ⼄盐 ᆠ泐�  � A   �  � B, 犨 �ᆠ  �矄 ᨨ犨ᆠᨨ矄 ᨨ   矄

矄  犨 ᨨ鼀ᨨ  矄矄 鼀ᨨ �ᆠ �矄盐 ᆠ y㦨a矄�  wt᠀kx᠀f㡰 ෌� 鼀 㦨aw㦨鼀⏌矄  �㡰 A鼀 㦨aw 㦨黨鼀⏌矄  ��㡰 ᨨᆠ�泐ᨨ 犨v㦨鼀⏌矄  ���㡰 �� � �⼄ ��㡰泐 �㡰

\

f A v A ⏌ l A v A = = f B vB ⏌ lB vB g A RTA MA g A MB =  㦨 g B RTB gB MA MB



�

p Ta l ᔼ   盐 鼀 鼀ᨨ  v l l +  r 㡰 = =  Þ v㦨f l +  r 㡰  f r㦨 㜠ᆠᨨᆠ�ᨨ � 盐 r 㦨 �盐矄ᨨ 盐㡰㦨�ᆠ鼀 l 㦨 � ᨨ 盐㡰㦨҈ᆠ鼀 f 㦨 ⼄盐 ᆠ泐ᨨ 盐 � � ᨨ├㡰㦨 \ᨨᆠ�泐ᨨ 矄ᨨ盐 � �v =  鼀⏌矄 㡰 ⼄盐 ᆠ泐ᨨ 矄ᆠᨨ  鼀ᨨ �ᆠ� �Aᨨ ᨨ  矄 㦨 ⼄盐 ᆠ泐ᨨ  �  鼀ᨨ �ᆠ� �Bᆠᨨ矄 ᨨ 

æ vA ö æ vB ö \  ç l ÷ =  ç l ÷ è Aø è Bø

ᆠ㡰 和ᆠh 犨�ᆠ鼀 bᨨh 矄 ␔矄ᨨ 盐ᆠ   矄矄�  盐

lf

T ⏌Ҙ   æ p x ö a 矄� ç ÷ dx è l ø l 

ᨨE 㦨

L

lf

T ⏌ Ҙ   ìæ p ö ü a 矄� íç ÷ xý dx l  îè l ø þ

ᨨ �泐ᨨ  矄� �

dE㦨pҘ

( 矄l A = lB ) (Q TA = TB )

M B ҈黨 � 䰘 和盐矄�盐� � M =  g A =   g B =  A

fA � ҈黨  = ´ = ҈   fB 和 ᨨ 矄ᨨ盐 v㦨鼀⏌矄  l      �  ᨨ  � ᆠᨨ盐鼀  ᆠᨨ矄ᨨ � � ᨨ   盐 鼀  ⼄盐 ᆠ泐 

v v  = ҈� Þ l 㦨 = =  鼀  l   ҈�㡰  ҈�㡰 \

l 

�

WWW.JEEBOOKS.IN

PS-161

鼀

Waves

鼀

鼀

鼀

҈鼀

鼀

鼀

҈鼀

l

矄矄盐

ᨨ 㡰 �矄ᆠ鼀   � ᨨ  x㦨 矄矄盐��ᨨ

�矄 ᨨ

㡰 꾀  泐 ᨨ矄��ᨨ  x   矄矄盐 DP㦨DPᆠᨨ矄kxᆠᨨ矄wt

ᔼ  ᆠᨨ矄  � ᨨ 泐 ᨨ  鼀ᨨ �ᆠ矄  ᨨ�   ᨨ犨  l҈ l   l   l   ᆠ     � 矄 ᆠᨨ矄ᨨ � � ᨨ    鼀ᨨ �ᆠ�  鼀ᨨ �ᆠ䰘  鼀ᨨ �ᆠᆠ 

鼀�盐 A㦨DPᆠᨨ矄kx㦨DPᆠᨨ矄

҈� ҈� L = 鼀 鼀�  ᨨ� 㡰 㦨   ´ ҈  é p ҈� ù DP ´ ú=  꾀鼀�盐 㦨DPᆠᨨ矄 ê  ⏌ 㡰  û  ë ᆠ㡰 꾀ᨨ   ᨨ �矄矄盐�矄犨泐矄矄鼀�⼄盐ᨨ

æ v ö 䰘ç ÷ 㦨҈� Þ l  㦨鼀錐 è l  ø ��

\

æ - dH ö a  gH 㦨 꾀 ç è dt ÷ø 和ᨨᨨ  ᨨ 犨�  �

æ - dH ö a  gH çè ÷= dt ø A 和盐矄�盐� � 盐矄犨�  ´ ҈ ´ H

- dH 㦨 ҈҈҈맔҈㡰 H dt 犨  �矄 犨ᨨ 矄ᨨ  ᆠ矄   犨  矄 ᨨ鼀 鼀ᨨ鼀

Þ

�

\

dH

Þ

ò

Þ

᲼  - 桌 = - ҈҈ ´ ҈- 㡰t

ᨨ 㡰

ᨨ 矄ᆠᨨ  ᨨᨨ  ᨨ    ᆠᨨ矄  �

H 

= -҈҈҈ ´ ҈ - dt

dH H

t

= - ҈҈҈ ´ ҈- 㡰ò dt 

t »  s

æ vö æ ö  ᨨ  = � ç è L÷ø è L ÷ø � ´  ҈� Þ L㦨 Þ = 鼀  ´  ҈

⼄盐 ᆠ泐 f = P ç

鼀 矄矄盐 Q DP =  P鼀 = P鼀� = P 㡰 꾀   ᆠᨨ矄    ᨨ  � 㝐 �鼀盐鼀矄矄盐鼀  㦨P졔DP 㝐� �鼀盐鼀矄矄盐鼀�  㦨PDP px ᆠᨨ矄 ( 黨pt ) �㡰 y㦨矄�  ҈� æ p xö 鼀�盐 A㦨矄�  ç ÷ è ҈� ø At x㦨�ᆠ鼀 꾀鼀�盐  ᨨ 鼀 �鼀盐鼀 �矄ᆠ鼀  æ p ´ �ö A㦨 矄� ç 㦨맔㦨ᆠ鼀 è ҈� ÷ø ��㡰 ᨨ 矄 ᨨ矄��ᨨ 犨 A㦨

æ px ö x㦨҈�

矄� ç ÷ =  = 矄� np \ è ҈� ø 犨  n㦨҈ x㦨҈�ᆠ鼀ᆠ鼀ᆠ鼀 ���㡰 꾀x㦨䰘�ᆠ鼀t㦨�ᆠ鼀ᨨᆠ�泐ᨨ �ᆠ dy æ p xö = 矄� ç v㦨 ᲼黨p矄�  黨pt㡰桌 è ҈� ÷ø dt æ p ´ 䰘� ö v㦨 矄� ç ᲼黨p矄�  黨p맔�㡰桌 è ҈� ÷ø æ pö 㦨 矄� ç ÷ ᲼- 黨 p 矄� p㡰桌 㦨 è ø æ p xö �㡰 y㦨 矄� ç ÷ ᆠᨨ矄᲼黨 p t 桌 è ҈� ø é ù æ p xö 㦨 ê 矄� ç ᆠᨨ矄 黨 p t 㡰ú è ҈� ÷ø ë û é æ p xö p xöù æ 㦨  ê矄� ç 黨 p t + ÷ø - 矄� çè 黨 p t ÷ è ҈� ҈� ø úû ë p xö p xö æ æ 㦨 矄� ç 黨 p t + ÷ - 矄� çè 黨 p t ÷ è ҈� ø ҈� ø 㦨y҈졔y  ᆠ ᆠᨨ鼀ᨨ  矄 犨矄 p xö y҈㦨矄� æç 黨 p t + ÷ è ҈� ø

ᨨᆠ�泐ᨨ  盐 v㦨  gH ᔴᨨ � 盐�泐⼄盐�ᨨ ҈ ��矄

- dH ҈ ´ ҈ - = dt ҈ ´ ҈-

p x l

ᨨ x =

æ v ö ç ÷ 㦨҈� Þ l҈ 㦨҈鼀錐 è l҈ ø æ v ö �ç ÷ 㦨҈� Þ l  㦨鼀 è l  ø

æ v ö 黨ç ÷ 㦨҈� Þ l  㦨鼀 è l  ø ᨨ �� 矄 ᨨ  犨     㡰 鼀   ҈㡰 鼀 㡰鼀  㡰鼀  ᆠ �� 矄ᨨ 犨鼀鼀҈鼀 鼀 A        ᨨ  ᆠᨨ矄矄㜠矄ᆠ�ᨨ 矄 ᨨ    �  ᨨ 矄ᆠ�泐 

A㦨p 맔҈㡰㦨҈맔҈鼀  a㦨p ҈㡰㦨҈맔҈鼀

矄矄盐 � ᨨ 㡰 ᨨ �矄ᆠ鼀  ᨨ  㝐ᔼ졠ᔼ x㦨졠 矄矄盐��ᨨ

x=x �矄鼀 ᨨ鼀�

�

p xö æ   y㦨矄�  ç 黨 p t ÷ è ҈� ø

盐ᨨ  ᨨ   矄  �  ᨨ  盐 l 㦨 ᆠ鼀 㦨 鼀 盐 鼀  ⼄盐 ᆠ泐 f㦨 ᨨᆠ�泐ᨨ 矄ᨨ盐 � �v㦨鼀⏌矄   v㦨 \ 㦨  l +  D㡰   +  ´ D㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-162

Physics

졔D㦨� Þ D㦨  Þ D㦨 ´ ҈ ᆠ鼀㦨ᆠ鼀 �鼀ᨨ 盐㡰 

盐ᆠᨨ矄 ᨨ 

졠矄 O D q

  = ⼄盐 ᆠ泐v㦨 » ҈  l + D㡰   +  ´ 㡰

Topic-3 : Beats, Interference and Superposition of Waves ҈ 

 

㡰 ᆠ㡰  ⼄盐 ᆠ泐 㦨 �  ᆠ �  ⼄盐 ᆠ�矄ᨨ  犨ᨨ犨矄 㦨҈҈黨㦨 㡰 㡰 ᨨ ⼄盐 ᆠ�矄ᨨ 盐 � � ᨨ├n᠀� ҈ ⼄盐 ᆠ泐ᨨ 矄ᨨ ᨨ鼀 犨� n µ l n + � ҈ \ = Þ 黨� n + �㡰 = ҈ n - �㡰 n - � 黨� ᨨ 黨�n졔䰘�㦨҈n�ᨨ�n㦨黨䰘�

黨䰘� = ҈黨�  � 㡰 ␔� � ᆠ矄�  矄�ᨨ   ⼄盐 ᆠ泐ᨨ 盐ᆠ 泐矄� � � ᆠ矄矄꾀矄 矄⏌矄ᆠ ᆠ矄矄  ᨨ ⼄盐 ᆠ泐ᨨ 盐 � � ᨨ├ ævö æ  ö f = ç ÷ +  = ç ÷ +  =  è l ø è  ´ 䰘� ø ᨨ n =

�



b㡰 ᨨ矄� � ⼄盐 ᆠ泐 f =

和ᨨ盐ᆠ V

ᔼ ��泐q犨�矄矄矄ᨨᆠᨨ矄q鼀ᨨ \vᨨ矄  鼀ᨨ  �犨� ᆠ矄



æ v + vc ö æ v + vc ö f = ç ÷ f҈ = ç v - v ÷ f è v ø c ø è é � + vc ù ҈ � + vc Þ  = ê = ú  Þ v � ҈҈ � - vc cû ë

Þ vc = � ├鼀⏌  

҈ F l m

�鼀 �ᨨ  T = l

� ´ ҈ - 㦨҈矄ᆠ ҈

�鼀⼄盐�  ᨨᆠᨨ 矄盐ᆠ��   ᆠ⼄盐ᨨ �鼀 �ᨨ ᨨ 犨盐矄  ᆠD㦨҈矄 ætö b㡰 ෌� ⼄盐�ᨨ y㦨ᆠᨨ矄 çè ÷ø 矄�  ҈t㡰 

\ T 㦨  ´ 

䰘



=   +  +  ´  ´  ´ ᆠᨨ矄

A҈ + A +  A҈ A ᆠᨨ矄 f

p = ҈ + 黨 +  = � 

Topic-4 : Musical Sound and Doppler’s Effect ҈



t æ ö 㦨 ç  ᆠᨨ矄  矄� ҈t ÷ è ø  ᨨy㦨᲼ᆠᨨ矄t졔҈桌矄� ҈t  ҈㡰 ᨨy㦨ᆠᨨ矄t矄� ҈t졔矄� ҈t  㡰 ᨨy㦨矄� ҈҈t졔矄� 黨黨黨t졔矄� ҈t  㡰  ᆠ ᨨ �� �ᨨ �ᆠ鼀ᨨ�ᨨ  �    鼀ᨨ �ᆠ 鼀ᨨ�ᨨ 矄  矄盐ᨨ矄  �㡰    矄 �  ᆠ犨    犨ᨨ犨矄 f㦨 p  矄盐  鼀�盐  A =

b㡰 ⼄盐 ᆠ泐   泐  ᨨ矄

vᨨ矄

æ ö v矄ᨨ盐 =ç ÷ v v q  ᆠᨨ矄 è 矄ᨨ盐 ø

㡰 ᨨ鼀  ᨨἘ矄 ᆠᨨ 矄ᨨ盐  ⼄盐 ᆠ泐  犨  fw = ×f  �㡰  - v v㦨矄 ᨨ 盐矄 f㦨ᆠ盐 ⼄盐 ᆠ泐ᨨ 矄ᨨ盐ᆠ ⼄盐 ᆠ泐    ᆠ�ᨨ  ᨨ鼀犨 f'㡰 �矄

 + v  + v × fw = ×f   - v  + v Þ 黨 = ×   - v  ´ 䰘 Þv= » � 鼀⏌矄 㦨 黨҈├鼀⏌矄 黨҈ ᆠ㡰 ᨨ鼀ᨨ矄 ᆠ ⼄盐 ᆠ泐ᨨ 矄ᨨ盐    f҈㡰犨 

矄ᨨ盐ᆠ�矄 ᨨᆠ � � c f҈ = f cv c 㦨 ᨨᆠ�泐 ᨨ  矄ᨨ盐 v㦨 ᨨᆠ�泐ᨨ 矄ᨨ盐ᆠ ⼄盐 ᆠ泐ᨨ 矄ᨨ盐    f㡰犨  矄ᨨ盐ᆠ�矄ᆠ � � c f = f c+v  ⼄盐 ᆠ泐㦨f҈f ҈ ù é ҈ Þ  = f҈  f  = f c ê  ë c  v c + v úû v = f c é v ù c  ê҈   ú ëê c ûú ᨨ c>>v c c � ҈ Þ v= = = = 鼀⏌矄 f  ҈   f

f Ἐ=

m F ҈ - 鼀矄矄 = � ´ ҈ - F㦨҈ m = 㦨   �

\

æ v ö 㡰 f҈   ⼄盐 ᆠ泐  泐犨 f҈ = ç ÷ f è v - vc ø v㦨ᨨᆠ�泐ᨨ 矄ᨨ盐  vc㦨ᨨᆠ�泐ᨨ ᔴ f㦨ᆠ盐 ⼄盐 ᆠ泐ᨨ ᆠ ᨨ

f  ⼄盐 ᆠ泐  泐 �  ᆠ�ᨨ  ᨨ鼀犨

�

ᆠ㡰 f҈㦨 f

v - v v + v  f㦨 f v v

盐 ⼄盐 ᆠ泐

v ff҈㦨 f ´ v



L

u

S

WWW.JEEBOOKS.IN

PS-163

Waves u  \ u㦨�鼀⏌矄 b㡰 ⼄盐 ᆠ泐ᨨ 矄ᨨ盐 矄ᨨ盐ᆠ 㡰 㦨 �  ␔   ᨨ矄�矄鼀ᨨ� �犨泐 ᨨ鼀 矄ᨨ盐ᆠ æ n - n Ἐ ö 꾀  ⼄盐 ᆠ泐 ҈ =  =  ç  �㡰 ÷ ç n ÷ è ø 꾀 犨   ᨨ矄�矄 鼀ᨨ� �ᨨ犨 矄  矄ᨨ盐ᆠ æ n - n³ ö  = � =  ç ÷  ��㡰 ç n ÷ è ø ᨨ鼀 ⼄盐�ᨨ  �㡰 æ  -  Ἐ ö  = � ç ÷ ç  ÷ è ø  㦨҈鼀⏌矄 ᨨ鼀⼄盐�ᨨ  ��㡰 æ  ἘἘ ö � = � ç҈ +  ÷ \ 㦨҈鼀⏌矄 ç   ÷ø è v - v 㡰 f '㦨 f v + vs ᨨ



䰘

é v ù  f = f ê Hz ú= f´ + v v  sû ë

҈㦨  ´

҈

҈

�矄  ᔴ矄҈␔   矄ᨨ盐ᆠ �矄鼀ᨨ� �ᨨ犨 矄矄�ᨨ 泐�矄 

 -  \f㦨�   +  b㡰 꾀ᆠᆠᨨ � �ᨨᨨ矄 ᆠ犨  矄ᨨ盐ᆠ�矄鼀ᨨ� �盐 ᨨ矄  矄 ᨨ  = f



é V ù  㦨  ê ú Þ  㦨  ëV  Vs û

é  ù ê ú ë    û

é  ù    㦨  ê ú ë  ҈䰘 û

҈

  ҈䰘  ҈黨 = 㦨 ᨨ ҈ =       ҈ 㡰 ⼄盐 ᆠ泐 ᨨ    矄ᨨ盐  ᨨ 盐ᆠ  泐ᨨ  盐

\

黨

æ v ö  ´  f = ç ÷ = =  Hz è l ø  ´ � � � m⏌s = ҈ 黨 꾀矄 矄ᨨ盐ᆠ�矄鼀ᨨ� �ᨨ犨 矄 ᨨ矄  ᨨᆠᆠᨨ � � ᨨ ᨨἘ矄  ᆠ \ ⼄盐 ᆠ泐 ᆠ  泐ᨨ矄 é � ù é v + v ù ê 黨 +  ú Ἐ㦨 ê ú f 㦨 ê ú  ë v û ê  ú ë û 黨黨� ´  ᨨ Ἐ㦨��� ;  㦨 黨 ´  㡰 ␔ ├ ᨨ犨       ⼄盐 ᆠ泐 æ  -  ö Ἐ= ç ÷  ᨨ鼀 ᨨἘ矄  ᆠ è  - 矄 ø 犨 㦨矄㦨鼀⏌矄ᨨᆠ�泐ᨨ ᨨ矄 矄ᨨ盐ᆠ 和 ᨨ 矄ᨨ盐 㦨鼀⏌矄 ᨨᆠ�泐ᨨ  ᨨ矄㦨 ҈ ´

҈

 졔   � 㦨   㜠  Q ⼄盐 ᆠ泐ᨨ 犨 �矄 㡰㦨�  é v ù  Hz 㡰 f҈ = f ê ú= f´  ë v - vs û

æ f ö æ  ö - ҈ ÷ ´ ҈ ; ҈奠 ç - ҈ ÷ ´ ҈ = ç f è  ø è ҈ ø 㡰 ෌�  ⼄盐 ᆠ泐 ᨨ  矄ᨨ盐  ᨨ 盐ᆠ  泐 矄�  f㦨 和 ᨨ ᨨ矄u㦨鼀⏌矄 ᨨᆠ�泐ᨨ 矄ᨨ盐 v㦨鼀⏌矄 ᨨᨨ 矄  矄ᆠᨨ 㦨䁸 ᨨᨨ  犨矄ᆠ� 泐 ᨨ矄矄ᆠᨨ 㦨졔l \ ᨨᨨ 矄⏌矄ᆠ æ  æ ö  Vö ´  㦨 - ç - ÷ = 㦨  çQ l = ÷ f ø l è lø l è   ´  ´  = ҈ 㦨  㦨� ᆠ㡰  꾀 鼀⏌矄 ᔴ

҈�

҈

æ  ö æ  ö   ⼄盐 ᆠ泐 h Ἐ = h ç ÷ = � ç ÷ 㦨�   è 矄 ø è  ø ᔴ矄␔  矄ᨨ盐ᆠ�矄鼀ᨨ� �犨泐 ᨨ鼀 矄�ᨨ 泐�矄  æ  ö æ  ö h³ = h ç ÷  = � ç ÷ 㦨黨 è  ø è  + 矄 ø ᔼ ᆠ矄҈ 盐鼀ᨨ 矄  �矄 � ᆠ矄 盐鼀ᨨ 矄  �矄҈  ᨨ ⼄盐 ᆠ泐ᨨ  矄ᨨ盐ᆠ㦨�҈ 㡰 꾀  ⼄盐 ᆠ泐ᨨ  矄�   泐 ᆠ � f¢ é v + vᨨ ù 㦨 f ê ú ë v - vs û 㦨鼀⏌矄 �� 㡰 � vᨨ㦨v矄㦨  ´ 㦨҈鼀⏌矄 ҈  é  + ҈ ù ᨨ f ¢ =  ê ú =  ´ ҈ » � ├ ë  - ҈ û b㡰 f҈㦨 ⼄盐 ᆠ泐 ᨨ    ᨨ�ᆠ ᆠ   泐鼀ᨨᨨᆠ泐ᆠ�矄 f 㦨 ⼄盐 ᆠ泐 ᨨ    矄�    泐鼀ᨨᨨᆠ泐ᆠ�矄  - v  + v ´ ҈䰘錐 f㦨 ´ ҈�錐 f҈㦨  -   Q f҈f㦨\ v㦨鼀⏌矄

æ v + vö b㡰 矄� �  ᨨ鼀盐f' = f ç A è v ø÷ v A + v �� VB + V  v = \ B =  =   � � v V v A

҈䰘

҈㡰꾀  ⼄盐 ᆠ泐  泐ᨨ矄 盐 ᨨ矄ᨨ盐ᆠ和

 é  +  ù é  + ҈ ù  v҈ = v ê ú = ҈ ê  ú = ҈ ´  = ҈   ë û ë û

鼀矄҈ 䰘 和

ᆠᨨ矄䰘

\ Ἐ㦨

҈҈

҈

҈鼀⏌矄

� ҈ᆠᨨ矄�

WWW.JEEBOOKS.IN

EBD_8341 PS-164

Physics

꾀  ⼄盐 ᆠ泐   泐ᨨ矄 盐 ᨨ 矄ᨨ盐ᆠ 和

æ v + v҈ ö f҈ = f  ç è v  v҈ ÷ø



é  +  ù é  + ҈ᆠᨨ矄 �° ù v = v ê ú = ҈ ê ë  -  ᆠᨨ矄 䰘° úû ë  - 矄 û

҈鼀

꾀  ⼄盐 ᆠ泐 �졠 盐ᨨ矄ᨨ盐ᆠB

A

q 鼀矄

q

q

v é ù nB = n ê úû + ҈ᆠᨨ矄 q v ë \

҈ᆠᨨ矄 q



é

v

ù

é

v

ù

 ⼄盐 ᆠ泐vb = n êë v - ᆠᨨ矄 q úû - n êë v + ᆠᨨ矄 q úû

҈ ҈ ù é = n vê ë v - ᆠᨨ矄 q v + ᆠᨨ矄 q úû ҈ ҈ é ù = ҈ ´  ê � �ú  + ú ê  -  ´ ҈ ҈ û ë ҈ ҈ é ù = ҈ ´  ´ ҈ ê ë  ´ ҈ - ҈  ´ ҈ + � úû ҈ ù é ҈ = ҈ ´  ´ ҈ ê » �  ë  黨� úû ҈黨

㡰

 -  l   æ  ö  Þ = ç ÷= l҈  l҈ è  -  ø l  l l  - l҈ -

 - 

Þ -҈ = -҈ Þ =   l҈ l҈

ᆠ �ᆠ  �⼄盐� �   � ᨨ  �

- l  - l҈ ´҈ = ´҈ = -�奠 l҈ 

ᆠ



ᨨ 㦨�鼀矄㜠҈

和ᨨ盐ᆠ  㦨黨

 ⼄盐 ᆠ泐ᨨ 矄ᨨ盐  ᆠ  ᨨ鼀 犨

é  +  ù é  + � ù  ;   ú  Þ vἘ㦨 ê ë  - � úû ë  - s û

nἘ㦨n ê

矄盐  ᨨ 鼀�盐  꾀

p p é ù = I  ê矄� O + 矄� + 矄�

+ 矄� p ú   ë û é  ù  = I ê + ú =  I   ë û

\ IR㦨AR㦨I \ n 㦨 䰘㡰 �矄泐 ᆠ 犨�    矄   ᨨ矄 犨 �ᆠ  �矄 ᨨᆠ � � 矄ᨨ盐ᆠ  �犨� 矄矄ᨨ盐ᆠ犨 �ᆠ �矄鼀ᨨ� ��   �ᆠ�ᨨ ᨨ 矄ᨨ盐  ⼄盐 ᆠ泐ᨨ  矄ᨨ盐  ᆠ  泐 ᆠᔴ҈

矄㦨�鼀矄҈ �鼀�ᨨ  盐矄 ᨨ鼀 泐  犨 矄矄矄ᨨ盐ᆠ㡰

é v ù é  ´  ù 黨 ´  = u ê c ú = 黨 ê ú =  =   ë    û ë v  vc û

҈

 ᆠ矄鼀矄盐ᨨ ᆠ �ᆠ  �⼄盐� �   � ᨨ ��矄�奠

ᨨ矄 矄ᨨ盐ᆠ鼀ᨨ� �ᨨ犨 矄ᆠ ᨨ  �鼀� ᨨ  矄ᨨ盐ᆠ矄矄矄矄ᨨ盐ᆠᨨ  ᆠ 矄ᨨ盐   � 矄 矄 ᨨ矄㡰

vc㦨鼀矄҈

é v + vc  v + vc ù é v + vc  v + vc ù = u ê ú = u ê ú v  vc v  vc ë û ë û

㡰

ö  ÷=  l ø

Þ

⼄盐 ᆠ泐ᨨ   ᆠ 矄ᨨ盐 矄ᨨ矄   矄ᨨ盐ᆠ



æ

  

è

æ v + vc ö v ÷ø



 l҈

␔  盐 � � ᨨ├�矄鼀ᨨ  Ἐ = ç

u҈㦨 u çè

\ ⼄盐 ᆠ泐㦨vv

ᨨ㡰 l҈㦨 � �� �  ᨨ � l㦨 犨 �  ᨨ �  㦨和 ᨨ 盐 � � ᨨ├ ᔼ ᆠᨨ矄 ᨨ�  � =

⼄盐 ᆠ泐 ᨨ矄   ᆠ

æ v ö æ v + vc ö u㦨 u҈ ç ÷ = v ç ÷  è v  vc ø è v  vc ø

ᔴ

 ( v҈  v ) æ ҈ ö \ç f= f è ҈ ÷ø v v  ҈  ´ ҈ = = ҈黨 鼀矄 ҈ = 䰘├鼀 ҈ ᨨ ( v҈  v ) =  

҈鼀矄 ҈ B

�鼀

�鼀



vv҈㡰㦨 vv㡰»v 矄v҈ v泐泐矄矄  v

҈鼀 和�ᨨ 泐㡰





æ v + v ö f  = f ç ÷ è v  v ø é v + v҈ v + v ù æ ҈ ö  ÷ø f  = f  ê ú \ f҈  f  = èç ҈ ë v  v҈ v  v û v ( v҈  v ) æ ҈ ö f ÷ø f = ᨨ çè ҈ ( v  v҈ )( v  v ) 

\ ⼄盐 ᆠ泐v 㦨҈҈҈䰘҈㦨҈� b » ҈  �㡰 꾀  ⼄盐 ᆠ泐 졠 盐 ᨨ 졠矄⏌�矄  和�ᨨ 泐 矄ᨨ盐ᆠA

v é ù nA = n ê  ᆠᨨ矄q ë v - ᆠᨨ矄 q úû



꾀  ⼄盐 ᆠ泐ᨨ 矄ᨨ盐  ᆠ 泐 ᆠᔴ

é  + ҈ ´  ù é  ù \ v = ҈ ê = ҈ ê ú ú = ҈҈䰘  ë  -  ´  û ë  û

҈

ᔴ҈



\ ⼄盐 ᆠ泐ᨨ  矄 㦨 nἘn㦨㦨  矄�  矄ᨨ盐 ᆠ 矄 ᨨ矄  � � ᆠ  ᨨ鼀 矄�ᨨ 泐 矄盐 ᆠ     鼀 �盐鼀 �矄 矄ᨨ 졠矄 ҈ 矄�ᨨ 泐 �鼀�ᨨ  矄ᨨ盐ᆠ犨� 和 和 ᆠᨨ鼀 矄ᨨ盐ᆠᨨ  ᆠ 矄ᨨ盐 

盐矄�  ᨨ    ᆠ矄矄ᨨ  矄ᨨ盐 ᆠᨨ鼀� � �ᆠ泐 ᨨ鼀 矄ᨨ盐ᆠ  ᨨ ᆠᨨ鼀� �  ᆠ�ᨨ 犨�    矄鼀   ⼄盐 ᆠ泐 ␔  ᆠ ᨨ矄犨�  

WWW.JEEBOOKS.IN

PS-165

Waves �

矄 �  矄�泐 ᨨ ᨨ盐 矄矄 ᨨ  矄ᨨ盐 

I㦨

҈ r V w  A 

æ v + vm ö f ἘἘ = ç ÷f è v  vb ø

꾀矄ᨨ �  矄�泐�矄 矄 �矄 ᆠ ᨨ鼀   ᨨ�  矄ᨨ盐ᆠ 矄

҈



䰘

 ᆠ  ⼄盐 ᆠ泐   泐鼀ᨨᨨ�矄

Iµ  r 꾀矄 ᨨ ᨨ  鼀矄ᆠ  �� �� ᆠ矄ᨨ ᆠ �� ᨨ ᆠ 泐矄ᨨ �  矄�泐犨�鼀�  矄鼀 꾀® ⼄錐® 錐ᔴ®  꾀㡰 �ᆠ ⼄ ⼄盐 ᆠ泐 㡰 ⼄盐�泐  犨 ᨨ鼀 ᔴ㡰 ᨨ盐 矄矄  �  矄�泐 泐 ᨨἘ矄 ᨨ鼀盐

æ v + vm ö æ v + vm ö fb = f ἘἘ f Ἐ = ç ÷ f ç ÷f è v + vb ø è v  vb ø ᨨ fb =

vb ( v + vm ) v   vb 

é  + 鼀 ±  ù ú ë  +  鼀 ± 矄 û



和�� ᆠᨨ  �ᨨ  ᨨVm�矄矄 ᨨᨨ犨矄 ᔼ 鼀 �盐鼀�矄鼀ᨨ� � ᨨ鼀sᨨO  졔 �ᆠ矄 和�鼀�泐v vsᨨ矄���  矄 �ᆠ  ᨨ鼀SᨨO  �ᆠ矄 㡰

 ᆠ 犨

鼀

nἘ㦨n ê

B = r

ᨨᆠ�泐ᨨ 矄ᨨ盐 � 犨v㦨

 ´ ҈黨

졠 黨



 犨 �矄 犨 �ᆠ  �矄 鼀�� � 矄ᨨ盐  �矄 � � ᨨ  �   ᆠ�ᆠ

ᨨ矄�矄� �矄 ᆠ ᨨ鼀 犨 �矄�졠 矄㦨w㦨鼀⏌矄

҈



㦨҈�鼀⏌矄

҈鼀⏌矄

㦨 ҈�鼀

鼀⏌矄

S  矄鼀�㡰

�  ␔



O ᆠ�㡰

w㦨 㜠҈

ᨨ㦨

⼄盐 ᆠ泐ᨨ 矄ᨨ盐 � 犨 v㦨

v犨 ҈� = = ҈�   T犨 ҈� ´҈

  㦨w 矄 㦨鼀⏌矄

෌� r㦨҈�鼀 w㦨 矄҈ 和 ᨨ 矄ᨨ盐ᆠvs㦨rw 㦨҈�맔㦨鼀矄҈ ␔   矄ᨨ盐ᆠ�矄 ᨨ矄��ᨨ A     ⼄盐 ᆠ泐  泐 ᨨ矄犨�鼀 �鼀盐鼀

⼄盐 ᆠ泐�矄�   ᨨ 鼀 �盐鼀\v犨㦨v� 鼀㦨졔鼀⏌矄錐㦨錐矄 㦨҈鼀⏌矄

é v + vm  v ù ú ë v + vm  vs û

꾀泐� � ᨨἘ矄 ᨨ鼀盐 vἘ 㦨 v ê \

(

)

 ù =  é  ù =   êë  -  úû ú  ë  - s û

é

nἘ㦨 n ê

� é ҈� +  -  ù \nἘ㦨҈䰘맔҈� nἘ㦨 ҈ ´ ҈ ê ë҈� +  - ҈ úû 

␔   矄ᨨ盐ᆠ�矄 ᨨ矄��ᨨ B     ⼄盐 ᆠ泐  泐 ᨨ矄犨�鼀� �鼀盐鼀

b㡰 ᔼ  �ᨨᆠ�泐ᨨ 矄ᨨ盐

g RT 㦨 㦨 M

é  ù  ù ú  =  ê  +  ú =  ë û ë  + 矄 û é

(҈) ´ ( ҈) ´ 黨 =  鼀⏌矄

nἘἘ㦨 n ê

 ´ ҈ 

 ᆠ    � ᨨ  ⼄盐 ᆠ�矄   泐   ᨨ矄 㦨 ᨨ 

vm㦨�鼀矄㜠҈ S



O ҈鼀⏌矄

= ҈  ⏌ 矄

ᆠ�㡰

æ v  v m  v ö ÷ è v  vm  vs ø

꾀泐� � ᨨἘ矄 ᨨ鼀盐 vἘ㦨 v ç \ 

(



nἘ㦨 ҈ ´ ҈

 �盐 ⼄盐 ᆠ泐ᨨ   ᆠᨨw㦨pn =  p ´

 - � -  ù 㦨҈맔҈  ) éêë  - � - ҈ úû

� p

 �盐 ⼄盐 ᆠ泐ᨨ   ᆠᨨ  矄ᨨ盐ᆠᨨ 矄ᨨ盐 ⼄盐 A w㦨҈ ⏌矄 ҈



鼀ᨨᨨ�矄 矄  ⼄盐 ᆠ泐矄 ᆠ�矄犨ᨨ �   ⼄盐 ᆠ�矄 ᨨ  �ᆠ泐 ᨨ鼀  矄ᨨ盐 矄ᨨ盐ᆠ ᨨ   f'  ᨨ  ᆠ  ᨨ鼀 犨 꾀  ⼄盐 ᆠ泐犨   �ᆠ矄ᨨ盐 ᨨ  �矄  泐  鼀ᨨᨨ�矄

æ v + vm ö f Ἐ= ç ÷f è v + vb ø 꾀��   ⼄盐 ᆠ泐犨     ᨨ  �ᆠ  ᆠ 矄ᨨ盐  泐  鼀ᨨᨨ�矄

鼀

A A

B

鼀 C

D

A

Þ ␔    ᆠᨨ�矄C鼀ᨨ� �ᨨ犨 矄D 矄ᨨ盐ᆠ�矄 A҈鼀ᨨ� � 犨 矄ᔼ�矄�  �矄矄�盐�ᨨ    ⼄盐 ᆠ泐  �矄鼀� �鼀盐鼀

WWW.JEEBOOKS.IN

EBD_8341 PS-166

Physics

é  -  ù  - 㡰 = �䰘  n鼀� 㦨n ê ú =  ´ + + 㡰    矄 ë û Q㦨꾀w㦨맔҈㦨鼀⏌矄 矄㦨 w㦨맔҈㦨鼀⏌矄㡰 꾀�� 犨    ᆠᨨ�矄C鼀ᨨ� �ᨨ犨 矄B 矄ᨨ盐ᆠ�矄 A鼀ᨨ� ��� 犨 ᔼ�矄�  �矄矄�盐�ᨨ    ⼄盐 ᆠ泐  �矄鼀 �鼀盐鼀

v㦨�鼀⏌矄

é  +  ù  + 㡰 = 䰘  ú =  ´    - 㡰 ë 矄û

矄

犨

é c -  ù nἘ㦨 n ê ú ë c - s û

矄

s졔�  泐 �ᆠ  ᨨ鼀矄ᨨ盐ᆠᨨ ᨨ矄 �  泐 �ᆠ  ᨨ鼀ᨨ矄ᨨ矄ᨨ盐ᆠ

é  - -�㡰 ù ú =   ë  - � û

nἘ㦨� ê



҈ 졠矄 ᨨ ᨨ├ ҈ 鼀ᨨ� � ᨨ犨 矄 ᨨ矄

\ ⼄盐 ᆠ泐㦨 vἘv㦨�㦨

v f Ἐ= f ( v  vs ) 犨 vs㦨ᨨᆠ�泐ᨨ  ᨨ├

Topic-5 : Miscellaneous (Mixed Concepts) Problems

ᨨ ᨨ├ 鼀ᨨ� �犨泐 ᨨ鼀 ᨨ矄

f ἘἘ =

v f v + vs 犨 v㦨ᨨᆠ�泐ᨨ 矄ᨨ盐 

҈

 = l

 n =

g

㝐 ´ ҈

-

´

҈ Þv㦨vl㦨n맔l l

v 㡰맔맔l㦨䰘鼀⏌矄ᨨ�鼀⏌矄 ᲼\l㦨�졔�桌 ᨨ鼀ᨨ ᨨ鼀�ᆠ�矄g㦨҈䰘

vf vf é ( v + vs )  ( v  vs ) ù  ᨨ  = vf ê ú v  vs v + vs êë ( v  vs )( v + vs ) úû vf ´ vs vf ´ vs ᨨ  = ᨨ  = 矄vsv   v v v s v  v  ´  v = = = ҈�鼀⏌矄 ᨨ vs = ᨨ s vf  f  ´ 

ᨨ  =

\  =

g

-

㝐 ´ ҈

= ҈ g ´

҈ 㝐

҈ ҈ =  㝐 㝐 䰘 ᨨNᨨ 㝐㦨\  =  ´ 㦨鼀矄҈ ҈ ҈䰘 㦨鼀矄҈ ᨨ꾀�ᨨ 㝐㦨 \㦨  ´  㦨 ҈䰘 ´

\和 ᨨ 盐 � � ᨨ├㦨҈�鼀⏌矄

ᆠ鼀㦨l

ᨨ �ᨨ鼀�ᆠ�矄g=҈

l⏌

l҈㦨�ᆠ鼀 l

㡰 Þ

\ ⼄盐 ᆠ泐㦨f'  f''㦨



ᔼ 和ᨨ盐ᆠ㡰

和 졠矄㡰

n鼀  㦨 n ê ҈

v㦨�鼀⏌矄

 = ҈



҈ ҈ = �黨 ´ 㝐 㝐 黨 㦨҈䰘鼀矄҈ ҈  \  = �黨 ´ 㦨�鼀矄҈ �

ᨨ졠 y� M㦨\  = �黨 ´ 泐 ᆠ矄� �  矄�ᨨ �  矄� � ⼄盐 ᆠ泐�矄 ᆠ矄� � \ �矄ᨨᨨ  ⼄盐 ᆠ泐ᨨ 矄� � 盐 鼀  ⼄盐 ᆠ泐ᨨ ᆠᨨ矄  � 㦨 

æ v҈ ö æ v ö é v ù ÷ç ÷ =  ᨨ v҈ = l҈ ê + ú \  ç l  û è l҈ ø è l ø ë 和盐矄�盐� � 盐犨 

 ù é = �m ⏌ s v҈ = � ê + ë  ´  úû ᨨ犨 v҈ =



T \ T = mv҈ m

 æ m ö  æ � ´҈ ö ÷ �㡰 = 䰘  ᨨT = ç ÷ v҈ = ç ç � ÷ èl ø è ø

ᨨN�ᨨ� M㦨 

b㡰 x  ᆠᨨᆠ�ᨨ 

l ᨨ l =  l҈ + x㡰  l  l  + x 㡰 = ᨨ l = l  + x㡰         = = \ n҈ 㦨 \n㦨 l҈  l҈ + x 㡰 l   l  + x 㡰 l҈ + x =

҈鼀㦨l҈

l҈ +x

�鼀㦨l 

l +x

ᔼ    矄ᨨ盐 ᆠ 矄   ᨨ矄   � �  ᆠ  ᨨ鼀  矄�ᨨ 泐矄盐 ᆠ  鼀 �盐鼀�矄矄ᨨ矄�ᨨ 泐 �鼀� ᨨ  矄ᨨ盐ᆠ ᔼ㡰�   ᆠ� �矄盐 ᆠ犨�ᆠᨨ鼀 矄ᨨ盐ᆠ ᨨ    ᆠ 矄ᨨ盐 

WWW.JEEBOOKS.IN

PS-167

Waves ෌� n҈㦨n \ 



�

  = ᨨ  l҈ + x 㡰  l  + x㡰

\  x㦨�鼀

v dn æ -҈v ö Vc 矄� a = - c 矄� a ´ ç  ÷= dt v è x 矄ᆠ  a ø x  矄ᆠ  a vc 矄� a dn = vc 矄�  a 꾀a㦨黨 \ dt = ҈ ᆠᨨ a 㡰  矄ᆠ  a

ᆠ㡰 꾀矄ᨨ w㦨pn Þ w µn E �鼀 =҈꾀鼀�盐 㦨A n҈㦨n E �鼀 =꾀鼀�盐 㦨A n㦨n

E A n = =  \ E㦨E҈ E҈ A n҈

dn = max dt

b㡰 矄 ᨨ ᆠ  盐矄�矄ᆠ鼀⏌矄 � ��泐犨ᨨ盐矄矄 ᆠ鼀 鼀ᨨ� �ᨨ犨 矄ᆠ ᨨ 



꾀  犨ᨨ 矄ᆠᨨ 矄 盐矄矄 犨� ᨨ ᆠ  ᨨ  꾀ᆠᆠᨨ � � ᨨ 矄盐ᨨ矄��ᨨ  � ᆠ�   矄� � 犨� ᨨ   泐 �矄ᨨ�ᨨ    犨�  矄��   ᆠ 犨� ᨨ쟼 ᨨ �泐犨�ᨨ 泐├� �ᆠ

黨

ᨨᆠ�泐ᨨ  矄ᨨ盐 泐 矄ᆠ  矄� �㦨

矄ᨨ  ᆠ �矄矄ᨨ鼀犨  矄 ᨨ  

 +e=

和 ᨨ  矄ᨨ盐  犨矄 �  犨 �矄 �    �  � 矄ᨨ 犨   矄  鼀 �盐鼀    ᆠ 矄ᨨ盐  犨 犨�  ᆠ � ᨨ犨 犨泐 ᨨ鼀   ᨨ鼀 bᆠ㡰

é v + vc ᆠᨨ矄 q ù é v + vc ᆠᨨ矄 q ù n P = V  V鼀 㡰 ê ú = ҈҈ - ҈҈ êë úû v v ë û n Q = ( vN  vM ) = ҈҈ - ҈҈ =  é v + vc ᆠᨨ矄 q ù é v - vc ᆠᨨ矄 q ù n R = ( vN  vM ) ê ú = ҈҈  ҈҈㡰 êë úû v v ë û \ n P + nR = nQ  vᆠᆠᨨ矄q q vᆠ 꾀 a Vx ᆠ ҈҈ ҈҈ ҈ 턼  㝐

ᔼ � 犨   ᆠ�矄矄矄� � ᨨ盐� 꾀

é v + vc ᆠᨨ矄 a ù n = ê úû v ë \

… �㡰

dn é v 矄� a ù d n = - ê c  �矄鼀 犨  矄� a㦨҈ da ë v úû d a

�a㦨黨  턼㡰

d n vc da =  矄� a㡰 … ��㡰 dt v dt ҈ dx ҈  da =-  꾀矄ᨨ  a = \ 矄ᆠ a dt x x dt

ᨨ鼀⼄ �㡰

҈  

ᨨ  犨 � ᨨ  矄ᨨ盐 � � 盐ᨨ  ᆠᨨᆠ�ᨨ  㡰

TἘ ҈�x T  = \ Ἐ㦨v 㦨v 㦨҈ T x Ἐ TἘ

䰘

b 㡰 ␔   矄ᨨ盐  盐矄�矄  ᆠ  ᨨ鼀 ᨨ    ᨨ  �  矄 ᆠ  �矄泐҈ 꾀 �� 矄矄盐盐矄�ᆠᨨ鼀矄矄�ᨨ �矄 ᆠ 矄ᨨ犨矄矄盐盐矄� ᆠ�ᨨ  ␔   矄ᨨ盐 盐矄�矄 ᆠ  ᨨ盐� ��� ᨨ盐 泐 ᆠᨨ矄  ᨨ �㡰 ᨨ 矄ᆠ  �ᨨᆠᆠ盐矄矄ᨨ �� 矄矄盐盐矄 �矄 ᆠ 矄 �� 矄矄盐盐矄 e  㡰

 � ᨨ  �ᆠᨨ盐鼀   �矄

T m

ᨨ鼀ᨨᨨ├Ἐ矄犨 矄�ᨨ � 矄� �T µ   矄�ᨨ x



… ���㡰

ᨨ鼀⼄ ��㡰 ���㡰

쟼 �泐 EµAn犨 A㦨鼀�盐  n㦨 ⼄盐 ᆠ泐

㡰

da -҈v =  dt x 矄ᆠ  a

҈

҈҈

҈

l 

Þ

 =

l -e 

 ᆠ矄ᆠᨨ 矄ᨨ  ᆠ  �  ᨨ �ᆠᨨ盐鼀 �矄鼀ᨨ矄 ᆠᨨ鼀 ᨨ �矄矄ᨨ  ᆠᨨ犨ᨨ �  � ᨨ �ᆠᨨ盐鼀  鼀ᨨ �矄   矄ᨨ�ᨨ  ᨨ   �泐  矄矄 �矄   �  矄�泐 ᨨ 矄ᨨ盐    b㡰 矄 ᨨ 矄ᨨ盐   矄ᨨ   鼀ᨨ   ᆠᨨ   ᨨ矄 和꾀㦨졔㦨鼀⏌矄  和㦨㦨҈鼀⏌矄 㡰 �矄 ᨨ�鼀ᨨ�ᨨ 犨 矄ᨨ盐ᆠ ᨨ矄 ᨨ  矄矄 �矄�  � 꾀和� ᆠ 矄矄 �矄� � A  鼀ᨨ� �犨� ᨨᆠ�泐ᨨ 鼀⏌矄  ᨨ  �矄�盐�ᨨ ᨨ 矄ᨨ盐 �  矄�泐ᨨ  犨 �矄 泐  矄矄 �矄� �  A�矄盐 � ᨨ鼀 㡰 ᨨ   矄矄 �矄 �  �   矄ᨨ盐ᆠ �矄 ᨨᆠ � � 犨� ᨨᆠ�泐 鼀⏌矄   ᨨ矄 �矄 ᆠ � � 犨�  ᨨᆠ�泐 鼀⏌矄

é v - v ù ҈ é  -  ù n Ἐ = n҈ ê ú  =  ê  -  ú =  ´  v v ë û ë sû é v - v ù ҈ n ἘἘ = n ê ú = ҈҈ ´  ë v - vs û \

n ἘἘ- n Ἐ 㦨 ҈҈㡰맔

҈ ҈ =  ´ = ҈    

҈ 㡰 ҈ ᆠ㡰 ҈� 㡰  ��  ⼄盐�ᨨ 矄 y҈ 㦨 A ᆠᨨ矄 � px  ҈ pt㡰  y 㦨 A ᆠᨨ矄  px  黨 pt㡰 矄 矄 犨ᨨ ᨨ�矄矄� 犨 � ��  矄鼀 �ᆠ�ᨨ ᨨ �x㜠 �矄犨� 矄��  �  ᆠ �   ⼄盐 ᆠ泐 ᔴᨨ鼀� ��犨�  矄  ⼄盐�ᨨ

y㦨Aᆠᨨ矄 kxwt㡰犨� w҈㦨҈p Þ pf҈㦨҈p Þ f҈㦨�  K҈㦨�p Þ

p = �p  Þ l҈㦨鼀 l҈

WWW.JEEBOOKS.IN

EBD_8341 PS-168

Physics

␔ᨨᆠ�泐㦨l҈f҈㦨鼀⏌矄᲼꾀 �泐盐矄v㦨 w㦨黨p Þ pf㦨黨p Þ f㦨

 ᨨ ⼄盐 ᆠ泐㦨f҈f㦨 

w 桌 K

 p = p Þ l㦨 K㦨p Þ  l  ␔ᨨᆠ�泐㦨 맔㦨鼀⏌矄 

v㦨

ᨨ

é

ì ax + bt 㡰 + ax - bt 㡰 ü ý  î þ ë ì ax + bt 㡰 - ax - bt 㡰 ü ù 矄� í ý ú Aᆠᨨ矄 ax졔bt㡰桌  î þû Þ y㦨҈A矄� ax矄� bt졔Aᆠᨨ矄 ax졔bt㡰

= A ê - 矄� í

�鼀� 犨 犨ᨨ矄盐ᆠᆠ矄矄�鼀 �鼀矄�矄p맔҈矄ᆠ ��㡰  ᆠᨨ ᆠ  ᆠ �  矄盐  �  矄�泐> A \ 矄盐  鼀�盐  >  A

犨  ҈A矄� ax矄� bt㡰�矄 ⼄盐�ᨨ ᨨ 矄 � �犨  Aᆠᨨ矄 ax졔bt㡰�矄 ⼄盐�ᨨ ᨨ � �犨

犨�矄� �� x �ᆠ�ᨨ  꾀 � ᨨ 矄 ᨨ� 矄犨   鼀�盐 �矄鼀 �鼀盐鼀

 A ᆠᨨ矄 p n҈ - n 㡰 t ³  A ҈ ᨨ ᆠᨨ矄 p n҈ - n 㡰 t ³ ᨨ  ҈ é w - w  㡰t ù ᆠᨨ矄 ê ҈ ú³   ë û ᨨ

é w҈ - w  㡰t ù

 ᆠᨨ�矄� 犨   盐矄ᨨ  ᆠᨨ矄 ê ú �矄  ë û ҈ 犨  

\

 p p w҈ - w  㡰t �矄犨      

dy 㦨Ab矄�  ax졔bt㡰Ab矄�  ax bt㡰 dt

㦨Ab᲼矄�  ax졔bt㡰졔矄�  axbt㡰桌 㦨Ab᲼矄� axᆠᨨ矄bt졔ᆠᨨ矄ax矄� bt 졔矄� axᆠᨨ矄btᆠᨨ矄ax矄� bt桌 v㦨Ab᲼҈矄� axᆠᨨ矄bt졔ᆠᨨ矄ax矄� bt桌

 鼀 �鼀盐鼀 ᨨᆠ�泐 犨� ᨨᆠᆠ盐 犨   矄�  ax 㦨 ҈  ᆠᨨ矄bt㦨҈盐  矄ᆠᨨ ��ᨨ ᆠᨨ矄ax㦨 矄� bt㦨 \ v鼀  㦨҈Ab 꾀矄ᨨv鼀�   㦨  㡰 y㦨᲼Aᆠᨨ矄 ax졔bt㡰桌᲼Aᆠᨨ矄 axbt㡰桌 㦨᲼Aᆠᨨ矄 ax졔bt㡰졔Aᆠᨨ矄 ax졔bt㡰桌 ᲼Aᆠᨨ矄 axbt㡰桌 㦨᲼Aᆠᨨ矄 ax졔bt㡰Aᆠᨨ矄 ax bt㡰桌 졔᲼Aᆠᨨ矄 ax졔bt㡰桌

w҈ - w  㡰 np t = np ᨨ t㦨  w҈ - w 

p p  np  n - ҈㡰p 矄 = ᨨ w҈ - w  w҈ - w  w҈ - w ҈

b p

b㡰 犨�矄 ᆠ 泐 ᨨ矄ᆠ�犨�矄盐  矄 �  ᆠᨨ p �  矄�泐ᨨ   ᆠ 犨�矄�鼀矄 ᨨ  � ᆠ�  犨 ᔼ  矄�泐ᨨ ᨨ��� 犨Iµ꾀 ᔼ  矄�泐ᨨ  ᆠ 犨I Ἐ㦨I Þ I ἘµAἘ Þ IµAἘ Þ AµAἘ Þ 꾀ἘµA 和ᨨ ⼄盐�ᨨ ᨨ  ᆠ 犨 y㦨Aᆠᨨ矄 ax bt졔p㡰㦨Aᆠᨨ矄 axbt㡰 ᆠ㡰  矄盐  犨 ⼄盐�ᨨ

y㦨y�졔y 㦨Aᆠᨨ矄 ax졔bt㡰졔᲼Aᆠᨨ矄 axbt㡰桌 �ᆠ ᨨᆠ�泐

㦨A矄� p n҈졔n㡰tᆠᨨ矄p n҈n㡰t 犨  鼀�盐 AἘ㦨Aᆠᨨ矄p n҈n㡰t ᨨ犨 �  矄�泐 µ 꾀鼀�盐 㡰 Þ IµAἘ IµAᆠᨨ矄p n҈n㡰t ᔼ  矄�泐犨�鼀 �鼀盐鼀 犨 

ᆠᨨ矄p n҈n㡰t㦨҈ ᨨ ᆠᨨ矄p v҈v㡰t㦨҈ ᨨ p n҈n㡰t㦨np

�鼀� 犨 犨ᨨ矄盐ᆠᆠ矄矄�鼀 �鼀

㡰 ᔴᨨ鼀 �� ⼄盐�ᨨ y҈㦨Aᆠᨨ矄 ax졔bt㡰犨�   矄  ⼄盐�ᨨ ᨨ   ᨨ�矄矄�犨

\ ⼄盐 ᆠ泐ᨨ  � ᆠ�  犨 n㦨

pn҈ + pn  㡰t pn҈ + pn  㡰t ᆠᨨ矄  

\

p p p p -  㦨 㦨 ´ ҈ 矄  w҈ - w   w҈ - w  㡰  w҈ - w  㡰

꾀矄ᨨpn㦨b

\ᔼ ҈矄ᆠᨨ y҈졔y㦨x㦨 ᨨ黨�鼀矄    犨ᨨ  �ᨨ 犨矄  矄   泐  ⼄盐�ᨨ 矄 y҈㦨A矄� pn҈t y㦨A矄� pnt 和� ᆠA҈㦨A㦨A   ᆠᨨ�矄x㦨

 ⼄盐�ᨨ  ᨨ  矄盐  犨 ᆠᆠᨨ � � ᨨ 矄盐ᨨ矄��ᨨ

� ᆠ� y㦨y҈졔y㦨A矄� pn҈t졔A矄� pnt 㦨A᲼矄� pn҈t졔矄� pnt桌

Þ

�鼀�㦨t҈t

p p æ p ö = a  Þ l㦨 x + pn t÷ Þ l a è l ø

n + ҈ 㦨ᆠᨨ矄᲼ n졔҈㡰p 黨pt Þ t㦨 ҈黨 ҈ ҈黨҈ = 黨� 犨  t㦨n㦨 -  犨  t㦨҈n㦨  

㦨A맔矄� 

\

y㦨Aᆠᨨ矄 ç

꾀x㦨 y҈졔y㦨 Aᆠᨨ矄҈pt㡰졔 Aᆠᨨ矄黨pt㡰㦨 Þ ᆠᨨ矄҈pt㦨ᆠᨨ矄黨pt㦨ᆠᨨ矄 黨pt㡰

҈

t҈㦨

㦨 ҈䰘

p p  t㦨 w҈ - w   w҈ - w  㡰

\

é

n



� 矄� ax㦨҈㦨矄�  ê np + -҈㡰  úû ë

é ë

ᨨ ax = ê np + ( ҈) ҈

n

pù  úû

ᨨ

é

x㦨 ê n +

êë

-҈㡰n ù p ú  úû a

�㡰  ⼄盐 ᆠ泐ᨨ  犨 �矄  泐ᨨ矄ᨨ   �

é

v + vw ù é ҈ +  ù = �黨黨  ú 㦨� ê v v v + ë҈ +  -  úû ë w sû

nἘ㦨n ê

��㡰 ᆠ ᨨ ᨨ鼀  ��矄  泐  �B犨 �ᆠ �矄  �矄 ᆠx ᨨ鼀  �矄ᨨ盐 ᨨ 盐ᆠ 泐�  �矄 ᆠ҈

WWW.JEEBOOKS.IN

PS-169

Waves ├鼀 ᨨ鼀  �

�鼀├ 泐  �ᨨᆠ  ᨨ鼀AᨨB

k x - y㡰 n + ҈ = p    n + ҈㡰 p 犨  㦨졔҈졔ᆠ xy㡰㦨 k

Þ

x 꾀

 ҈├鼀

҈- x t҈㦨 

ᨨ �



 �㡰

�鼀├ 泐 ᆠ ᨨᨨᆠ  ᨨ鼀 � t㦨tAH졔tHB

҈ x + t㦨 ҈ + 㡰 ҈ - 㡰

 ��㡰

n㦨

é v - vw 㡰 + vs ù ú ë v - vw 㡰 - v û é ҈ - 㡰 +  ù 㦨 � ê ú ë ҈ - 㡰 -  û

҈

nἘἘ㦨n ê

҈黨

Þ k x㦨

Al r ù T é ê 犨  m = 鼀矄矄  盐 � � = l = Ar ú M ë û YAaDq Y aDq = = Ar r

v=

㦨҈

\v = 

x - y㡰 é k x + y 㡰 - wt ù ᆠᨨ矄 ê úû   ë

 矄盐  �  矄�泐犨�  ᨨ 犨 

k x - y㡰 k x - y㡰 =   Þ  ᆠᨨ矄 =  

黨 ´ ҈

҈ 鼀ᨨ �ᆠ

㦨䰘鼀⏌矄

 鼀ᨨ �ᆠ



n + ҈  n + ҈㡰 p p  Þ x㦨 犨 n㦨҈  k

Þ z㦨Aᆠᨨ矄

҈ ´ ҈҈҈ ´ ҈䰘 ´ ҈ -� ´ 

꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ    � �鼀矄 A   B  矄 � ᨨ ��ᨨ 矄ᨨ 矄鼀 ⼄盐 ᆠ泐� �鼀 C�矄  ᨨ  和ᨨ A  B � ᨨ 矄 ᨨ鼀 

n + ҈㡰 p 

��㡰  矄矄犨z҈� �� 졔x㜠 �矄 z� � � 졔y㜠 �矄 z҈㦨Aᆠᨨ矄 k xwt㡰 z㦨Aᆠᨨ矄 k ywt㡰 ᔴᨨ鼀� ᨨᨨ 盐ᆠ犨� ��   �ᆠ�ᨨ 鼀├� �

 �ᨨ � 犨�   ᨨ矄��x ᨨ矄��y 矄

矄盐 犨z㦨z҈졔z z㦨Aᆠᨨ矄 k xwt㡰졔Aᆠᨨ矄 kywt㡰

 A ᆠᨨ矄

҈  ´ ҈҈҈ ´ ҈ - ´ ҈҈ ´ ҈ -� ´  㦨҈҈  ´҈ ҈ F A Dl  Dl㦨l a Dq 㡰 矄� �y㦨 l \ F = YAaDq 和  ᨨ   矄矄 犨

�㡰  ␔   犨ᨨ �  �ᆠ犨矄 � � �  ᨨᨨ矄�  �ᆠ�ᨨ

矄盐�鼀ᨨ矄 犨 � 矄 � � 犨矄  ᆠ ᨨᨨ犨� �犨ᨨ⼄盐�ᨨ 矄 犨�ᨨ 盐ᆠ矄 � �犨 z҈㦨Aᆠᨨ矄 k xwt㡰 z㦨Aᆠᨨ矄 k x졔wt㡰

矄盐 犨�矄�� 泐z㦨z҈졔z Þ z㦨Aᆠᨨ矄 k xwt㡰졔Aᆠᨨ矄 k x졔wt㡰 㦨Aᆠᨨ矄k xᆠᨨ矄wt

 矄盐  �  矄�泐犨�  ᨨ 犨 

Aᆠᨨ矄k x㦨

Þ ᆠᨨ矄k x㦨ᆠᨨ矄

҈ T ҈ YA a Dq = l m l m

㦨

҈- x ҈ x = +  ҈ +  ҈ - 

Þ x㦨黨�├鼀

 ⼄盐 ᆠ泐ᨨ ᆠ ᨨ矄  泐  �

Y㦨

⼄盐 ᆠ泐ᨨ  盐 鼀 鼀ᨨ ᨨ ��ᨨ

犨  tAH 㦨 �鼀 ├  泐矄ᨨ盐  ᨨ鼀 A ᨨ � 犨�  ᨨᆠ�泐 ҈졔㡰 tHB㦨�鼀├ 泐矄ᨨ盐  ᨨ鼀 �ᨨB犨� ᨨᆠ�泐҈ ᨨ鼀⼄ �㡰  ��㡰 t҈㦨t Þ

矄矄矄 꾀

\T㦨YAa Dq = = 矄� Dl l a꾀Dq Dl = a Dq 㡰 (Q Dl = la Dq Þ l 矄� �

졠 ᨨ  ᔴ

꾀 � ᨨ  꾀 �鼀

v҈ v ´ p҈ =  ´ p Þ l l

꾀 � ᨨ   �鼀

p҈ v҈  = = ᨨ҈҈p҈㦨p p v ҈҈

�  �  鼀ᨨ �ᆠ� AC�矄⼄盐ᨨ҈҈  鼀ᨨ �ᆠ� CB ᨨ犨  盐 鼀  ⼄盐 ᆠ泐� AC 㦨

v҈ ҈҈ = = ��  l  ´ �

   盐 鼀  ⼄盐 ᆠ泐� CB 㦨

v  = = ��  l  ´ �

\ ⼄盐 ᆠ泐� AC㦨맔��㦨҈�   ⼄盐 ᆠ泐� CB㦨҈҈맔҈�㦨҈�

WWW.JEEBOOKS.IN

EBD_8341 PS-170

Physics

Electric Charges and Fields

15

ÞF 㦨Fᆠᨨ矄q

Topic-1 : Electric Charges and Coulomb's Law

Fnet =



҈

æ y + a ö ç ÷ è ø q æ ö kq ç ÷ y  Fnet =  è ø ⏌ y + a 㡰



㡰  졔턼



⏌

 =

ᨨᆠ 盐ᨨᆠ �⼄

졔턼

⏌

 =

ᨨᆠ 盐ᨨᆠ �졔턼

⧤턼턼

 ⧤턼⼄

æ ö ç ÷ èø

Þ





ᨨ ⼄盐���盐鼀

r r  +  =  

b㡰

Þ

├턼턼

├턼⼄

+

㦨  ( ⏌  ) 꾀 턼 = ò r  = ò    ⏌ ( p   )  

æ ç  ⏌ =  p꾀 ò   =  p 꾀 ç  ç  è  턼 㦨 p꾀 ҈ ⏌㡰

⏌





\⼄ = -

㡰

q

a

a

Þ F矄� q

q

x

y + a

Qya㡰

和ᨨFµy

㡰 q l

 ⼄ = 鼀� p Î  ´ 鼀�

矄� q ⼄ ⏌ 矄ᨨ  q » 矄� = l ⼄ ⼄  l  Þ =  ᆠ l = p Î 鼀�  p Î  ´ 鼀�

q

ᆠᨨ矄q





鼀�

҈⏌

䰘



æ ⼄l ö ÷÷ \ = çç è p Î 鼀� ø ҈⏌

 ᨨ µl

ᆠ �㦨 㡰 ␔    ᨨ矄�� ᨨ�  ᆠ � �矄 ᆠ  ᨨ盐矄�   ᆠᨨ 盐ᆠ� �矄   +  �鼀 ᨨ ᆠ �├矄ᆠᨨ

+ +  矄盐 ᆠ矄矄 ᨨ犨 �   ��盐盐 +

 ᆠ � ᨨ    矄  �矄 ᨨ 矄 ᨨ 졔⼄ + ᆠ � 矄   ᨨ      矄  b㡰 ᔴ � q 矄ᨨ �� ᨨ⼄盐���盐鼀  ҈ ҈ ҈ 졔턼 ҈ ⼄ l

 

졔턼 l

ᔴᨨ 矄� � �⼄盐���盐鼀ᨨ ᆠ �q졔҈ F҈㦨F҈

KQ ´ Q l㡰 黨



=

KQ ( - q ) l



\q㦨 -

Q 

æ ҈ q ö çç ÷ ÷ è p Î L ø ᨨᆠᨨ  ⼄㡰 盐ᨨᆠ �犨� �ᆠ ᆠ ᨨ盐泐 ᨨᆠᨨ  ⼄㡰 盐ᨨ ᆠ  �ᨨ 꾀和�鼀�泐 ᨨᆠᨨ ⼄ 盐 ᨨᆠ �쟼犨��ᆠ ᆠ ᨨ盐 盐ᨨ ᆠ �ᨨ  和ᨨ   ᨨᆠ 犨� ᆠ盐矄 ᨨ  ᆠ � ⼄ ᨨ  ᔴ ᨨ 泐 �

F矄� q F ᆠᨨ矄q

y 

 q =

ö ÷ æ  ö  ⏌  ҈) ÷ = p꾀 ç   ÷ (  è ø ÷ ø 

F

a

×

鼀� = ᆠᨨ矄 q



ᆠ㡰 ᔼ 矄�    ᆠ�泐  ᆠ � �矄 ᨨ \ Q҈ 㦨    s1 㦨 

�矄 ᨨ ᆠᨨ ᨨ� ᆠ �矄졔QQ � 盐ᆠ ᆠ � ᨨ  �

 矄盐 ᆠ ᨨ    ᨨ盐 矄盐 ᆠ \ Q 㦨    s2 㦨  y

kq  y



ᔼ ⼄盐���盐鼀  = 矄� q

턼 

æ ö ç ÷   ҈ = ᨨ� ç ÷  ç҈ 턼 ÷ p꾀 ø è 㡰 和 矄꾀 ᆠ泐⼄盐ᆠ �矄泐Ἐ⼄Ἐ ├⼄⼄ \ ᨨᆠ犨  鼀 =  ⼄ ␔  꾀 ᔴᨨ盐ᆠ  ᆠ �ᨨ ᨨ  ⼄ 꾀 = ⼄ ᔴ = 

 犨   ᔴᨨ盐ᆠ  ᆠ �ᨨ  ⼄ +⼄ ⼄ ⼄ =  =   ᨨ犨  ᨨᆠ犨 ᆠ �⼄꾀 ⼄ ⼄ ⼄ ├⼄ 꾀 ⼄  ├ ´  ´   ├⼄   Ἐ = = = =     

F �

æqö kq ç ÷ èø

F=

҈ q  犨ᨨ   ᆠ��  盐 p Î L

WWW.JEEBOOKS.IN

PS-171

Electric Charges and Fields

҈

҈°

Y”

KQ 



҈҈

FR㦨Fᆠᨨ矄 q

㡰ᨨ 泐ᆠᨨ矄�ᆠ ᨨᆠᨨ 盐矄�ᨨ �矄ᆠ� �  L 犨 �ᆠ 犨�├ 犨ᨨ矄矄 矄ᨨ矄矄�  �犨

 犨ᨨ矄� �矄犨�҈ 

 矄�ᨨ � ᆠ 矄� �犨�⼄盐ᨨ ᆠᨨ矄�ᆠ ᨨᆠ ᨨ  盐矄�ᨨ

졠 ҈ 턼 턼 턼҈㦨턼㦨턼  㦨

㦨맔

㦨

\

҈ pe

(R

Qx 

)

 ⏌

+x

=

҈Q ´  R  ù⏌

pe é R + (  R) ë û 

=

QR

pe  � � R

҈�

ᨨᆠ㦨qE

-QR

҈

҈

�.e.  ᨨᆠ�矄 ᨨᨨᨨ�ᨨ ᨨ �矄ᆠ鼀  pe  � �R  ᆠᆠ ��ᆠ犨� ᨨ ᆠ盐矄�鼀 鼀ᨨ �ᆠ鼀ᨨ�ᨨ  T盐

鼀�ᆠ矄 犨 �ᆠ �矄 ��泐ᆠ � �� 矄ᆠᨨ 矄    ᆠ�矄鼀矄矄� ᆠ矄矄

鼀�ᆠ矄 犨 �ᆠ �矄ᨨ矄��泐ᆠ � ᨨ矄矄ᆠᨨ 矄    ᆠ�矄鼀矄矄 ᆠ矄矄  ᆠ㡰   ᆠ�ᆠ ᨨᆠ ᨨ  泐 矄  �矄 q 矄矄盐泐ᔴᨨ盐ᨨ鼀犨   ᨨᆠ 盐 ᨨ ᨨ 

矄  ᨨ  ᨨ  鼀�

ᆠᨨ矄  q  矄鼀 q ᔼ ⼄盐���盐鼀

矄�

 q 졠

ᆠᨨ矄q㦨鼀� 鼀�   矄� q㦨  \  q =  �㡰 鼀� 꾀矄 ᨨᆠ犨 犨ᨨᆠ �ᨨ �矄ᆠᆠᨨ � �ᨨᆠᨨ盐ᨨ鼀Ἐ矄犨 ᨨ矄 ᨨ   盐ᨨ    鼀 �盐鼀  ᆠ ᨨᆠ 犨   鼀 鼀� 矄鼀  ᆠ �鼀鼀矄 �  �ᆠ�ᆠ鼀 �盐鼀 꾀矄��  ᨨᆠ  ��  �q

e

æ r ö   Ἐ ᆠᨨ矄 q= 鼀� ç ҈ -  ÷ è r矄 ø \  q = e r   ��㡰 鼀� ҈ -  㡰 r矄 ᨨ犨⼄盐� �⼄  �㡰 ��㡰 r ҈  ҈ ҈-  = Þ҈= ҈ r矄 e  r矄 \ r矄㦨├�⏌鼀  ᆠᨨ�ᨨ  ᆠ㡰�矄ᆠᨨᆠ

Ἐ 矄� q=

꾀  矄�ᨨ  Ἐ =

҈

x + a 㡰

㜠q

´

F矄� q 

㡰 F

x

x + a 



k Q q x

a㡰 턼

q q

 ᆠᨨ矄q F 㜠q

x  + a  㡰 ⏌ 

 㜠a㡰

F 矄� q 



Q´Q Q ҈ ҈ T㦨 ´ = ´  p e  L㡰   p e   L 矄 쟼ᆠ�ᆠ � ᨨ � �矄ᨨ � � E=

kQq



= e  ҈

 ᆠ ᨨ�ᨨ  㡰 �矄 � ᆠᨨᆠ 㡰 盐矄ᆠᨨ 矄�  ᨨ矄��ᆠ �Q �矄 ᆠx ᨨ鼀  ᨨ���  ᨨᆠ犨 Q qF졠 矄ᨨ� � �矄 ᨨᆠF矄� q ᆠ ᆠ矄ᨨ盐 矄盐  ᨨᆠ

҈

和� ᆠFR�矄 ᨨᨨᨨ�ᨨ ᨨx 鼀ᨨ�ᨨ �矄 ᨨ矄�鼀 鼀ᨨ �ᆠ

ᆠ �Q犨�ᆠᆠ� ᨨ���  �� ᨨᆠ�泐꾀  ᨨ���    ᨨᆠ�矄 ᨨ盐 盐ᨨ鼀ᨨ鼀 盐鼀�犨�ᆠᨨ矄矄 ᨨ���

 鼀ᨨᨨ犨 矄 꾀矄� ᆠᨨ鼀矄 ᨨ  �� x㜠 �矄   ᨨᆠ�矄 �� ᨨ犨 矄 ᨨ���   ᆠᆠ �턼犨� ᆠ盐ᨨ矄ᆠ�ᨨ泐盐 ᨨ矄�鼀 鼀ᨨ �ᆠ 鼀ᨨ�ᨨ  㡰 ᔼ Q҈QQ Qᨨ矄��    ᨨᆠ犨� ᨨ �졔y㜠 �ᆠ�ᨨ 矄ᆠᨨ鼀ᨨ  矄ᨨ  ᨨᆠ矄ᨨ �x㜠 �矄ᆠ ᆠ ᨨ盐ᆠ  ᨨ  ᔼ Q҈Qᨨ矄�� QQ ��  ᨨᆠ犨�ᆠ ᨨ � 졔 x㜠 �ᆠ�ᨨ  矄 ᆠᨨ鼀ᨨ  矄 ᨨ  ᨨ矄 ᨨ � y㜠 �矄ᆠ ᆠᨨ盐ᆠ ᨨ  ᔼ  Q҈ Q  ᨨ矄��   Q Q  ��    ᆠ� ᨨᆠ犨� ᨨ鼀� 盐矄� ᨨᆠ   ᨨᆠ犨�ᨨ � y �ᆠ�ᨨ  ᔼ  Q ҈ Q ᨨ矄��   Q  Q  �� ᆠᨨ鼀ᨨ  矄 ᨨ  ᨨᆠ矄 ᨨ �y㜠 �矄ᆠ ᆠᨨ盐ᆠ ᨨ 和ᨨ  ᨨᆠᨨ ᆠ �qᨨ � x㜠 �矄 쟼ᆠ  �ᆠ犨�  �  ⼄盐���盐鼀 盐   ᆠ ᨨ   ᨨᆠ  矄�ᨨ ᨨ 矄� �T犨�� � �矄盐  ᆠᨨ矄�ᆠ ᨨᆠFᨨ   犨ᨨᨨ ᆠ �矄 ᨨᆠF 鼀� �ᆠ盐

矄ᨨ� � T �    �ᆠ�ᨨ  ᨨ  mg   F   泐� �   ᆠᨨ ��ᨨ  ᨨ  ⼄盐���盐鼀 Tᆠᨨ矄 q 㦨mg錐 T矄� q 㦨F F \  q 㦨  �㡰 mg   F㦨 FCA + FCB +  FCA FCB ᆠᨨ矄 a

\

   + FCA +  FCA ´ F㦨 FCA

F㦨 FCA =  ´

kq 

҈ 

 ��㡰 ur ur  a㦨 桌  F CB  =  F CA  T鼀├  � q 犨�  �ᆠ  㡰 - ҈�㡰  㦨҈䰘鼀 OC㦨  \ OM㦨黨黨黨䰘 OC ҈䰘 = \ q 㦨  ���㡰 OM 黨黨黨䰘 ᨨ鼀⼄ �㡰 ��㡰  ���㡰

CA㡰 

҈䰘  ´ 黨 ´ ҈黨 ´ ⼄  = 黨黨黨䰘 㡰  ´ ҈- ´ 黨

\q㦨҈맔҈黨ᔴ

WWW.JEEBOOKS.IN

EBD_8341 PS-172

෌� 㝐矄矄ᨨ �ᆠm㦨黨맔҈├� ᔴ �ᨨ �ᆠq㦨҈ᔴ Q + + r㦨҈鼀錐 + + Q㦨҈�ᔴ + r +

ᆠ�ᆠ �  盐盐 � ᨨ鼀泐 + + ᆠ � � �ᨨ  �盐矄rᨨ�  + �矄 x ᨨ鼀�矄ᆠ ᨨ �矄 �矄 x

Qx

E㦨 k

 r  + x  㡰 ⏌  \ ᨨᆠᨨ   ��ᆠ � qF㦨qE

\ ᨨ

- kQq

´x ᨨ r  + x  㡰 ⏌  Qq A㦨k ´x  m r + x  㡰 ⏌ 

F㦨

ᨨ xr A = -

kQq 

+

+ + + +

҈䰘

Physics

+

+ + + +

 ᨨᆠᨨ ᆠ �q├A 盐ᨨᆠ �矄├B C F҈㦨Fᆠᨨ矄

æ q ö F҈㦨  ´ ç 黨 ´҈黨 ÷ ç a ÷ø è

 ᨨᆠᨨ q 盐ᨨᆠ � q㡰├D q ö 黨 æ ´ ç 黨 ´ ҈黨 ´ ÷ a ⏌ 㡰   çè a  ÷ø ᔴ泐 犨ᨨ ᨨᆠ矄 ᨨ⼄盐꾀矄ᨨ矄F>F҈ ᆠ �矄 犨�鼀ᨨᨨ犨 矄 ᆠ 

q

F㦨黨맔҈黨

Fixed ring

-k Q q

mA㦨

r  + x  㡰 ⏌ 

w㦨

\

p = T

kQq mr



´x

kQq mr 

B

kQq mr 

é 㦨  ê K ëê

é 黨 ´ ҈- ´ ҈ ù T㦨맔҈ ê 黨 -� - ú ëê 黨 ´ ҈ ´ ҈ ´ ҈ ûú 㦨᲼҈桌҈⏌㦨᲼҈桌㦨矄 ᔼ  ᆠ �矄q҈ q矄�鼀��  盐  ᆠ�ᆠ ᨨᆠ qq F = ҈  犨�盐矄� �矄ᨨᨨ矄�ᨨ 矄�ᨨ  ᨨᆠ T' l 꾀

⼄҈

P

a  㡰

 

҈黨

q a

+K

q

C

é q ù   q´q ù +  êK ´ ú ú 黨 a ⏌ 㡰  ûú a ûú ëê

Topic-2 : Electric Field and Field Lines ҈

ᆠ㡰 쟼ᆠ�ᆠ �  盐ᆠ �Q E = 쟼ᆠ�ᆠ �  盐ᆠ �Q҈ E҈ = Q҈ A



mg

ᨨ⼄盐���盐鼀ᨨ  P mg ᆠᨨ矄 㦨 TF㡰ᆠᨨ矄a  �㡰 N҈㦨mg ᆠᨨ矄 졔 TF㡰矄� a  ��㡰 和�鼀�泐 ᨨ ⼄盐���盐鼀ᨨ   Q mg 矄�  㦨 TF㡰矄� a  ���㡰 N㦨mg ᆠᨨ矄 졔  㡰ᆠᨨ矄a  �㡰 �㡰�� � �⼄盐�ᨨ  ���㡰泐 �㡰犨�  㦨 a �a 㦨  㡰 ᨨ犨 ��㡰 ᨨ鼀⼄盐�ᨨ  ���㡰TF㦨mg ᨨ 㦨 졔mg㦨 q҈q⏌l㡰졔mg  �㡰 ���㡰 ᨨ鼀⼄盐�ᨨ  ��㡰N҈㦨mg ᆠᨨ矄 졔  㡰矄�  N҈㦨mg ᆠᨨ矄 졔mg矄�  \N҈㦨 mg  ��㡰 ᨨ鼀⼄盐�ᨨ  �㡰N㦨mg ᆠᨨ矄 졔mg ᆠᨨ矄 㦨mg ���㡰 꾀�� �   ᆠ ᨨ �矄 ᆠ盐   T ᆠᨨ鼀矄 ᨨ  ᆠ ᨨ鼀 ⼄盐�ᨨ  �㡰 q҈q㦨mgl  � 㡰

�矄矄 ᨨ犨矄 q҈ q鼀盐矄 盐 �├ᆠ �矄 ᨨ 矄ᨨ 鼀�  矄�ᨨ 泐 �㡰  ᆠ �矄ᆠ ᨨ 盐qᆠ  ᆠᨨ 矄 ᨨ   ⼄盐�� �  ᨨ盐  ᆠ �Q�矄ᆠ   ᆠ ᨨ  � �矄矄 ᨨ犨 �   ��盐

kQ x

kQ҈ x҈



ᔴ mg

F

Aq

a



 

 㡰

 

q q q 㦨K맔  +   K  㦨   + 㡰 K  a a a

�矄�矄 鼀ᨨ盐 ᨨ 犨ᨨ├   ᨨ鼀ᨨ ᆠ �矄ᨨ� � �泐

 Q ⼄

黨 a

F

qQ 黨  q  q =Q 맔 K  ´ 㦨 ´ K ´  Þ    黨 a a

ᆠ �턼矄 ᨨ盐  �� ᨨ � �泐ᨨ    矄泐矄鼀

mr  ÞT㦨p kQq



q

F ᆠᨨ矄  a

��㡰 ᨨ ᆠ �矄 ᨨ 鼀�  矄�ᨨ 泐

҈⏌ 

҈

a  D Q

a

´x

ᨨ w㦨

=

A q

r  ᆠ 鼀ᨨ�ᨨ �矄矄�鼀 鼀ᨨ �ᆠ�  盐 ᔴᨨ鼀� � ᨨ⼄盐�ᨨ 犨�  A = -w  x \

q

q E

x

q E 

ᨨ鼀 ��盐 E x  q =  = ҈ Þ E҈ x



q

黨q

O

B

Q



kQ x = ҈ kQ҈ x ´  x҈  Q x x Q x Q x Þ  ҈ = ҈ Þ  =  ᨨ ҈ = ҈  x Q҈ x҈ Q x Q҈ x ᆠ㡰 ᨨ 矄 �ᆠ 矄  ҈ Q E= �  r ³ R 㡰 pe  r  㦨 � rR㡰 ᨨᆠᨨ ᆠ �� ᆠ�  � F㦨qE ᨨrR㡰 \F =  ҈ Qq F= ᨨr  R㡰  pe  r  x

WWW.JEEBOOKS.IN

PS-173

Electric Charges and Fields 

ᆠ㡰 ᆠ�ᆠ � ᨨ 盐ᆠ  盐ᨨ盐 � ᨨ鼀泐ᆠ � � � �  �矄盐 � ᨨ鼀和ᨨᨨ�ᨨ  㡰  㡰犨ᨨ � 꾀  졔 ᆠ �  矄�泐s졔 �矄 ��� �  鼀� �盐  矄ᨨ �矄 � ᨨ �Y �ᆠ�ᨨ 犨����   � ᨨ ᆠ �  矄�泐s � X �ᆠ�ᨨ  ᆠᨨ�ᨨ  ᆠ㡰�矄ᆠᨨᆠ s E҈ ER ER s E

E A ҈ ´ � æ 黨 ö 黨  ҈ = =ç ÷= ´ =  ´ ҈䰘 è ҈䰘 ø ҈䰘   EB ᆠ㡰



쟼ᆠ�ᆠ �  E = E ҈ - x 㡰

b㡰 矄� � vu㦨aS  �㡰 u㦨s㦨x 꾀矄ᨨ Fᆠ�ᆠ 㦨 ma

\ ᨨᆠ F = qE = qE ҈ - x  㡰

ÞqE㦨ma Þ a =

E E E ҈

E

E

ᆠ㡰 ෌� 

꾀矄ᨨ F = ma = mv

dv dx

dv ö æ çèQ a = v ÷ø dx

v = 黨

qE ҈ - x  㡰dx Þ v dv =  m ᔼ �� �ᨨ  矄� 矄犨� v



qE ҈ - x  㡰 dx 黨x ö v  qE æ x Þ = ç ÷= ò m m çè   ÷ø  x

ax =

  ᆠᆠ�ᨨ  ᨨ �ᆠ�矄ᆠᨨ 矄  � �� ᨨᆠ�泐�矄 ᨨ   ᨨ   �矄 矄��  �  ay = g



 쟼

졔s  졔s



r s  ᆠᨨ矄 ° xˆ  矄� ° yˆ 㡰   E = e 

s æ ҈  ö yˆ ÷ çç  xˆ  e  è   ÷ø 쟼ᆠ�ᆠ � �  ��ᨨ 矄 ᨨ犨 �  ��盐 㡰

E m

r r r æ s é ҈ ö ù EP = E҈ + E = ê  xˆ + çç҈  ÷ yˆ ú e ëê   ÷ø úû è 

a=

æ E ö  çè ÷ +g mø

҈

Rö æ b㡰 쟼ᆠ�ᆠ � 꾀 ç R Ἐ = ÷ ø è q E A ds = e



A 3R 



r s ( R ⏌  ) æ sR ö =ç ÷  Þ E A = e  è e  ø æ Rö e  × p ç ÷ èø 쟼ᆠ�ᆠ � 矄�B

r Þ EA =



=

r F = qE�ˆ + mgˆ

 æ Rö r´ p ç ÷  èø

쟼҈



ᨨ鼀 ��盐 r s E҈ = yˆ e 

Þx=





qE x m



 a 㡰  ᨨᆠ ᆠ� � ᨨ

  �ᆠ

)

qE qE Þ a= m m 和盐矄�盐� � 盐矄�  �㡰犨�

dv \ mv = qE ҈ - x  㡰 dx

Þ ò v dv =

r r E 鼀盐矄 �ᨨ p \ Eˆ �矄ᨨ �ˆ +  ˆ -  kˆ

(

졔s

졔s

E

�

r r

和� ᆠ r × p = 

䰘

҈



r ҈䰘 æ sR ö sR sR Þ EB = Þ EB = ç ÷ e �e � è e ø





 æRö  k ´ r´ pR k ´ r´ p ç ÷ r  èø  EB =  R  æ Rö ç ÷ è  ø

 r sR æ ҈ ö ( s ) p æ R ö Þ EB = -ç ÷ ç ÷ e è pe ø æ R ö  è  ø ç ÷ è  ø

⏌

r xˆ ù s éæ ö ᨨ EP = êç҈  ÷ yˆ  ú e ëêçè  ÷ø  ûú ᆠ㡰 ᔼ     �ᆠ�ᨨ

Fx㦨qE Þ ma x㦨qE E q Þ ax =  m ᨨ 矄  ᨨ  ᨨ盐

v + vx = v 㡰  Þ v x =  v = a x t Þ v =  + ®

®

®

®

®

qEt Þ t= m

v m E q

҈҈ 㡰 E = E + E 㡰 + E + E 㡰 ҈    ᨨE㦨Eᆠᨨ矄aEᆠᨨ矄b –q d q d d q d –q

E3 a D

E1

WWW.JEEBOOKS.IN

EBD_8341 PS-174

㦨

Physics  kq 



D + d 㡰

D

´

D + d 

kqD

=



 ⏌

D + d 㡰 ᨨ 



D 

-

-

 kq 

D + d 㡰



D

´

D + d 㡰

kqD 

᲼ D + d 㡰 桌⏌

ᆠ㡰 �  � 矄 ᨨ���   �ᆠ盐 ᨨ鼀 ᨨ矄�� ᆠ �  鼀�  �ᆠ盐 ��ᆠ � 盐  �矄矄泐矄鼀 ᆠ   矄 ᆠ�ᆠ �ᨨ ҈ 㡰 쟼ᆠ�ᆠ �  盐 ᨨᆠᨨ鼀 �矄ᆠ R 㦨 a㡰   �矄 ᆠ x   ᨨ  �矄  �矄 ҈�

é ù x s ê҈  ú  E҈ = e  êë R  + x  úû s é h ù é x 㦨h ù ҈ = e êë a úû ëê   R = a ûú E҈ =

҈

µ

D D ҈ 㡰 꾀⼄盐���盐鼀矄盐  ᨨᆠᨨ ᨨ鼀盐矄  ᨨ矄ᨨ Tᆠᨨ矄q㦨mg  �㡰 T矄� q㦨qE  ��㡰 Y 和ᨨ� � �㡰  ��㡰犨�  q =

qE mg

 -

� ´ ҈ ´ 

҈ =  q = -   ´ ҈ ´ ҈

҈

T

X q mg ᲼q㦨�맔҈ ᔴ 쟼㦨⏌鼀鼀㦨맔҈├�桌

 ᆠ c =



҈ Q · 錐 pÎ R  Q⏌ ҈ Q ҈ E = E = · · pÎ R  錐 pÎ R 

҈

쟼Ἐ =

\쟼Ἐ = 

é R R ù é R ù =  pr ê - ú = pr ê ú  úû êë  êë ҈ úû

=

pr R 

æ pr R ö Epr = ç  ÷ è  Î ø \

쟼ᆠ�ᆠ � ᨨ盐矄�   E =

s  Î

r R  ҈ Î r 

ö ÷ ÷ ø

æ ç҈ ç  +  è

ö ÷ ÷ ø

s æ  - ö  ç ÷÷  = 쟼  Î çè  ø ҈

 ö æ çè 쟼 - 쟼÷ø ´ ҈ ҈ ҈ 奠 ; 䰘䰘奠 = = 쟼 ҈ 㡰 Wh  h ᆠ�ᆠ �  �矄 ᨨ

ᔼ ⼄盐���盐鼀 ᨨᆠ 盐ᨨᆠ�ᆠ � 㦨犨��  qE㦨mg Þ qE㦨



æ ç҈ ç  +  è

\奠 盐ᆠ�ᨨ �  盐ᨨ ᆠ�ᆠ �

҈黨



s  Î

ᨨ鼀⼄盐矄�ᨨ  㦨   �盐矄ᨨ  �矄ᆠ㡰

ò çè҈ - R ÷ø r dr  = pr ò r dr - rR dr R

s �� 㡰  Î

쟼ᆠ�ᆠ � ᨨ �  �矄 泐 �矄 ᆠ  ᨨ鼀 ᆠ ᨨ   �矄ᆠ

éé  ù R é  ù R ù ù é  ê ê r ú - ê r ú ú =  pr ê R - R ú =  pr     êê  ú ê R ú ú êë   R úû ë ë û ë û û

q=

ᔴ泐E>E҈>E 㡰 쟼ᆠ�ᆠ � �  矄�泐 ᆠ  ᨨ   �矄ᆠ

쟼=

Qdv㦨p 㡰 

s ae 

E҈ =

҈䰘 ᆠ㡰

ò



a ᨨ

h ù s é hù s é ҈  ҈   㦨 sh e êë a úû e êë a úû e a

q�n = dq = rdv

 =  pr

a

s æ hö ç҈  ÷ e  è a ø 쟼ᆠ�ᆠ �  盐 ᨨ ��  �矄ᆠ E 㦨 E҈  E

)

rö æ = r ç҈ - ÷ pr  dr è Rø

ù ú úû

E =

)

(

é h ê҈   êë a + h

和�鼀�泐 ᆠ�ᆠ �  盐 ᨨ  �矄ᆠ  R 㦨 a㡰

q

æ҈ö Þ  -҈ ç ÷ èø b㡰 쟼ᆠ�ᆠ � ᨨ   �矄ᨨ � �ᨨ  �盐矄  �矄 ᆠ  ᨨ鼀  ᆠ  ├턼 쟼= ⏌  +  쟼 = ᔴᨨ ��ᨨ  ᨨ鼀 �鼀盐鼀 ᆠ�ᆠ �  é ù d ê kQh ú Þ ú =0 dh ê   ⏌ ê R +h ú ë û 泐盐矄� � ᆠᨨ ᆠᨨ 鼀 �鼀 鼀� �鼀犨� =  rö æ 㡰 ᔴ �  矄�泐 r = r ç ҈ - ÷ è Rø dq㦨rdv

(

҈

q qE

s e 

  pR rg pR rg  \ q =  E

 �㡰

Wh  h ᆠ�ᆠ �  �矄 矄犨�ᆠh  ᨨ ␔�� ᨨ   ᨨ㦨 �矄ᆠᨨ盐矄 ᨨᆠᨨ   ᨨ 鼀�㦨 phRvt

WWW.JEEBOOKS.IN

PS-175

Electric Charges and Fields

  pR rg = phRvt \ R = 

黨hvt rg

é s s $ s s ù $ + + ú - k 㡰 㦨 - e k  ë e  e  e  û

㦨 ê

 ��㡰



 é 黨hvt ù  rg ´ ᨨ鼀⼄ �㡰 ��㡰 q = p ê  ë rg úû E



 ᆠ �矄 ᨨ    矄盐 ᆠ矄 ᨨ    鼀�ᆠ 矄 矄 

矄 ᨨ犨  �    ��盐 ᆠ �  矄�泐 σ㦨 ⼄盐矄�ᨨ

Q҈  pR =



=



Q҈ + Q p  R 㡰

 p R 㡰



 졔



Q҈ + Q Þ Q = Q҈ 





Q҈+ Q㡰 졔







 –Q҈







졔 Q҈ 

R



















Q҈+ Q+ Q 











�









R





R 





 졔

Q҈ + Q + Q = Q҈ 黨





  졔

 䰘

졔 졔

b㡰    ᆠ �  盐 � ᨨ盐鼀 s O ᆠ ᨨ 盐 � ᨨ鼀矄 ᆠ � 矄ᨨ� 矄  盐矄ᆠᨨ 矄�  盐 � ᨨ鼀泐ᆠ � 矄 ᨨ  �� ᆠ �   矄�泐s � ��矄ᆠ  OἘ꾀矄ᨨ OOἘ⼄盐ᨨa



ur s uur E = r Ἐ \  ᨨ ᆠ�ᆠ � e  ur ur ur s E = E҈ + E  = a e   ᆠᆠ�ᆠ � 犨�  � �盐犨 �ᆠ 犨�盐 � ᨨ鼀 ᆠ㡰  �ᆠ�ᨨ ᨨ ᆠ�ᆠ � 矄ᆠᆠᨨ � �ᨨ ᆠ � ᨨ  矄 矄�ᨨ � ��z㜠 �矄 E1 E3 Z=a

E2

2 -2s

 ᨨᆠ�ᆠ � ᨨ�  P

ur ur ur ur E = E҈ + E  + E  㦨E҈ - k$ 㡰 + E - k$ 㡰 + E - k$ 㡰

3 -s

E

+ R

E E

S



\E㦨

rR pR r ҈ pR r ⏌  rR =   㦨  e ´  ´ e 黨 ҈ pe  R pe   R 

\k㦨 㡰  矄 �ᆠ矄 ᨨ  �盐矄x  �ᆠ├ 矄矄dx ᨨ盐鼀ᨨ  �矄矄 㦨px dx㡰ᔴ � ᆠᨨ矄 �  �矄矄   dq = px  㡰 dx ´ kx a ᨨ dq = pkx  + a dx  ᨨr=R 

ᨨᆠ � ᆠᨨ矄 �   矄 ᨨ  �盐矄R R

Q=

\

ò

E҈ =

 pk x  + a dx = pk

dx x

R + a + a 

쟼ᆠ�ᆠ � r㦨R

҈ pkR + a ҈ pk ҈+ a = R  pe   + a 㡰 R  pe   + a

ᨨr=R⏌

ᨨᆠ � ᆠᨨ矄 �  矄 ᨨ  �盐矄R⏌ R⏌

Z = –a

O

E

Q ҈ pe  (  R ) 

lᆠ泐� 㦨 pR r

꾀矄ᨨ ᆠ�ᆠ �  盐ᨨ矄鼀矄 

P

pe  (  R )



 졠¢



Z = 3a

g



ur s ur E҈ = r҈ e 

1 -s

r

+T

pR  r  æ Rö 턼矄 㦨 p ç ÷ r =  è ø 

 盐矄 ᆠᨨ 矄�    �泐 ᨨ�  P �    矄鼀矄   ᆠ�ᆠ �  盐ᨨᆠ �ᨨ ��矄 盐矄� �෌盐矄矄Ἐ矄 ᨨ鼀



-



r҈ 

E U

㡰 ᆠ�ᆠ� 矄ᨨ  ᨨᆠᆠ

ᨨ  鼀�ᆠ矄 矄 쟼 㦨  � 矄�    矄ᨨ� 鼀�ᆠ 矄 꾀矄ᨨ   ᆠ�ᆠ � 矄 ᨨ ᨨᆠ ᨨ  鼀�ᆠ矄盐 ᆠ ᨨ鼀泐 ᆠ㡰 쟼ᆠ�ᆠ �  泐犨  � 矄�    鼀�ᆠ ᨨ�ᨨ  � ᆠᨨ 盐ᆠᨨ ᨨ 矄 �矄 ᨨ 쟼ᆠ�ᆠ � � 矄犨泐矄 ᨨ鼀ᨨ矄盐 ᆠ ᆠ㡰 쟼ᆠ�ᆠ� 矄ᨨ  ᨨᆠ ᨨ ᨨ ᨨ鼀ᆠᨨ矄 ᨨᨨ矄 㡰 鼀� �盐 ᨨ  ᆠ�ᆠ �  ᨨ� P犨 �ᆠ  �矄  �矄 ᆠR ᨨ鼀  �矄ᨨ  ᆠ泐�  쟼㦨쟼ᨨ쟼ᆠ�泐 㦨

ÞQ҈Q㦨Q ÞQ҈Q҈㦨�Q҈㦨Q \ Q҈  Q  Q = ҈   � ҈

E

ur ur E졔 E 㦨 E 



  Q҈+ Q㡰

 졔

Q҈ + Q + Q

\ Q҈ =

ᆠ �   矄   졔

r

和�鼀�泐 쟼ᆠ�ᆠ �  盐 ᨨ Q ᨨ O�矄ᆠ ᆠ 泐ᆠ�ᆠ � 盐ᨨT O

ᆠ�ᆠ �  盐ᨨRᨨ O�矄 �  矄鼀 �ᆠ�ᨨ 矄 ᨨ U ᨨ O ᆠ  ᆠ�ᆠ �

ᨨq㦨䰘맔҈҈黨ᔴ b㡰

Kq

쟼ᆠ�ᆠ �  盐ᨨPᨨ O�矄ᆠ ᆠ 泐ᆠ�ᆠ �  盐ᨨS ᨨ O P+Q



é 黨 ´ ҈ ´ ҈-� ´  ´ ҈- ù  黨 ´ 黨 ´ 䰘  = ´pê ú ´   ´ 黨 ´ 黨 ҈p ´ ҈� ë û 

ur

쟼ᆠ�ᆠ �   E =

ᆠ㡰

QἘ =

\

ò

pk x  + a dx =

 pk R ⏌ 㡰+ a + a

ᆠ�ᆠ � r = R⏌

E =

҈ pk R ⏌ 㡰+ a ҈  pk æ R ö = ç ÷   pe   + a R ⏌ 㡰 pe   + a è  ø

҈+ a

WWW.JEEBOOKS.IN

EBD_8341 PS-176

Physics

҈ E  ҈ ҈+ a ҈  pk æ R ö ҈ ҈  pk ҈+ a = ´ R çè ÷ø  pe  + a 㡰  pe   + a 

Q  E = \

盐 矄� q =

�鼀ᨨ  ��  ҈ = 泐

=

Þ ҈졔a㦨\a㦨 黨

⼄E꾀㡰和� ᆠᆠᨨ矄�ᆠ � �矄ᆠᨨ 矄� � \ WPQ 졔 WQR 졔 WRS㡰졔WSP㦨 ᨨ WPS졔WSP㦨ᨨ WPS㦨WSP \

(

=

)



҈





(



�鼀



E

B � � A

E

KP R

P O

⧤ 

⧤ 

�   �ᆠ�ᨨ  ᨨᨨ矄� ᨨ   �ᨨ    ᆠ�ᆠ � 矄 ᨨ盐 ᆠ ᆠᨨ盐 �矄 � �EB㦨 ®

r - ⧤

ᆠ�ᆠ � 꾀

q

E

ᨨ  ᆠ�ᆠ �ᨨ ᆠ�ᆠ �   盐ᨨ �ᨨ�矄

®

⼄ 㦨鼀  㦨⼄쟼\泐 = 쟼 泐 㦨  맔҈҈ 鼀 é ⼄ ù ҈ ᔴ├� -҈ ҈ �� 㡰 ú Q = êë 鼀 û



  ´҈҈

�ᆠ  ᨨ鼀졠ᨨ꾀㡰矄ᨨ� 꾀�矄ᨨ   �� ᨨ ᆠ�ᆠ �ᨨ   ᆠ�ᆠ � 쟼矄 ᨨ盐 矄ᨨ�   �ᆠ�ᨨ

ᨨ 졠ᨨ꾀 ᨨ犨ᆠᨨ 矄� � �ᨨ� 犨 �ᆠ �矄ᨨ� ᨨ  ⼄盐�ᨨ�� 

 � 㦨�鼀

盐 =  ҈ ´҈ 鼀矄 -҈

 

ᨨ犨ᆠᨨ 矄� � �ᨨ� 꾀 ᆠ�ᆠ �  盐ᨨ �ᨨ

盐  쟼  =

Þq㦨 ᨨ҈Þ q㦨 ᨨ �ᆠ �矄 �� q㦨 ᨨq㦨

)

ᆠ�ᆠ �矄 ⼄盐�ᨨ � 꾀矄ᨨ KP/R ᆠ�ᆠ � �矄 ᨨ鼀ᨨ矄盐ᆠ  E ⼄ �    �矄   �ᆠ�ᨨ  ᨨ ᆠ�ᆠ �  �矄 �   � ᨨ   鼀� �盐  ᨨ  ᆠ�ᆠ � 矄 ᨨ盐  ᨨᨨ� 矄ᨨ    ᆠ�ᆠ



 Þ 矄� q = 

 ´  ҈ ´҈ ´

P ˆ ˆ � +    

ᔼ ��矄 ᨨ  ᆠ � �ᆠ 盐 =  ҈ ´ ҈ 鼀⏌矄

盐  矄� q  ´ ҈҈ 矄� q Þ�=  � 㦨 泐   ´ ҈҈

  ´ ҈҈

b 㡰 ෌�  �ᨨ鼀ᨨ鼀 ᨨ ᆠ�ᆠ �ᨨ P =

\ WPS㦨WSP㦨qEa \␔ᨨ├ ᨨ 泐 � ᨨ �ᨨᆠ矄矄PQRS㦨qEa 矄 ᨨ�ᆠᨨ鼀ᨨ�  ᆠ�ᆠ盐鼀ᨨ�ᨨ 犨  ᆠ � ᨨᆠ犨 �ᆠ �矄 ᨨ� T盐

 ᆠ�ᆠ �  ᨨ 盐ᆠ  犨     ᆠᆠ�ᨨ �矄 盐 � ᨨ鼀  ᨨᆠ ᆠ� � ᨨ  ᆠ �  �ᆠ ᆠ  �  

ᆠ�ᆠ � �矄�� 泐F㦨qE  ᆠ   ᨨᆠ矄 ᨨ    犨ᨨ ᨨᨨ 矄  �  �ᆠ � � ⼄盐 ᆠ � 盐 � ᨨ鼀ᆠ�ᆠ �  T盐 ␔   ��  �泐X㜠泐鼀 矄 �犨�├ ᨨᆠ├ᨨ盐 ᆠᨨ 矄 ᨨ鼀   矄鼀鼀 盐ᨨ ᨨᨨᆠ�ᆠ  ᆠ 鼀├� �� ᨨ矄��泐ᆠ �   ᆠᨨ矄�ᆠ ᨨᆠ�    �ᆠ�ᨨ ᨨ ᆠ�ᆠ � ᆠ矄  ᨨ 犨�   ᆠ �   �ᆠ�ᨨ ᨨ ᆠ�ᆠ �  r -҈ bᆠ㡰෌� ᆠ�ᆠ �  쟼 泐 = -  ᔴ

҈ 

� m矄 ᨨ q= ° 㡰 

ur

WSP = qEa



� m矄 ᨨ q = ° 㡰 

盐 矄� q =

�鼀ᨨ  ��   = 泐

r uur ␔ᨨ├ ᨨ 㦨 qE SP (\ F = qE ) r r WSP = qE�ˆ ( rP  rS ) (Q E ҈҈´  �矄 )

WSP  qE�ˆ a�ˆ + bˆ

 ´  ҈ ´ ҈ ´

쟼꾀 =

r ⧤

 �㡰

R ®

®

®

®

+ 쟼  㦨 - 쟼 + 쟼  = - 쟼    ҈ ´  꾀��  ᨨ鼀⼄ �㡰쟼㦨 pÎ  R  㡰 \ �

 㦨 p Î 쟼  

҈⏌

é  ù \ 㦨 ê ú  쟼 pÎ   û ë

㡰 盐矄ᆠᨨ 矄� ᨨ� 㝐� 矄�  ᆠ�泐犨 ᆠ�ᆠ � 矄ᨨᆠᆠ盐 꾀矄矄盐鼀 ᆠ�泐ᨨᆠᨨ � 矄�鼀�ᆠ � �矄�盐�ᨨ ᨨ ᨨ矄��  ��ᆠ � 矄 矄ᨨ 矄  쟼ᆠ�ᆠ � M 盐ᨨ盐 � ᨨ鼀泐 �矄�盐 ᆠ �ᨨ  犨 ᨨ 矄  ᨨ  �盐矄R҈

r r r E҈ = r e



쟼ᆠ�ᆠ �   㝐 盐 ᨨ  

�� ᆠ � �矄�盐�ᨨ  �    ᆠ�泐

ur r uuur E = MP e

㝐 

  졠



\ ᨨᆠ�ᆠ � 㝐� 矄�    ᆠ�泐

ur ur ur r r r uuur E = E҈ + E  = r+ MP e e

WWW.JEEBOOKS.IN

PS-177

Electric Charges and Fields

ur r r r r r r uuur r a  r éQ r + MP = a ù E= r+ ë û e e ur r r \ E= a e ur  ᆠ� 矄�   ᆠ�泐 E  �矄 盐 � ᨨ鼀  ᨨ  �矄 鼀� �盐  r   �ᆠ�ᨨ   ᨨ  a 

(

\

)

r



ᆠ㡰

҈

쟼ᆠ�ᆠ � 쟼҈ 盐ᨨ矄鼀矄 �꾀

҈ E҈ = pe

 꾀

Q

E҈㦨 pÎ r  

졔Q 졔 졔 졔

r

졔졔 졔졔 졔졔

r

E㦨

҈

l pÎ r

҈ 턼 s = Þ 턼 = ps  pÎ  Î

㡰

쟼ᆠ�ᆠ � E 盐ᨨ���矄 �B

  p R r R r R ҈  ( )  E = =   pe e ( R ) E҈ = E 

쟼 r㡰㦨쟼 r㡰

҈ l s l = Þ  = pÎ  Î sp ᆠ㡰

= Q

쟼҈ ⏌㡰㦨

҈ 턼 p Î 

 ´ l ҈ ҈ l ´ =  p Î  p Î   E҈ r㡰㦨E r㡰

\ Q㦨lr

黨

é ҈ l ù ҈ l ú= ë pÎ  û  pÎ 

꾀 E r⏌㡰㦨  ê

҈ 㡰 E r⏌㡰㦨 p Î s s = E r⏌㡰㦨  Î Î 䰘

  p R r ҈  ( )  E = pe ( �R ) E҈졔E㦨

҈ pe \

    pR r҈ p (  R ) r ҈   + =   pe   R ( ) ( � R )

r҈  = r �

r҈ R r R =   Î ´   Î

Þ

r҈ = r

 㡰 ᔴ泐 ᨨ鼀 ��盐ᆠ�ᆠ � � 矄ᨨ�� � � ᨨ鼀Q҈ 鼀� � �ᨨ Q \ Q҈�矄ᨨ矄�� Q �矄 �� 盐鼀ᨨ  ᆠ�ᆠ � � 矄ᨨ��� � � ᨨ鼀 Q҈�矄 鼀ᨨ 

鼀� � � Q \Q҈>Q 和� ᆠ � � �矄 ᆠᨨ �� ᨨ Q ᆠ�ᆠ � �矄 ᨨ

ᆠ�ᆠ � ᆠ 泐Q�ᆠ盐ᨨ� 犨�ᆠ ᆠᨨ盐  ᆠ�ᆠ � ᆠ 泐Q҈盐   � � �矄 ᆠᨨ    ᨨ Q҈ ᆠ�ᆠ � �矄 ᨨ 㜠 ᨨ ᆠ㡰

ᆠ�ᆠ � � 矄�  矄 

҈ Qq r  pe  R 

E

ᨨEµr졠盐矄�  矄  Rr¥㡰E㦨 ᨨEµ

҈ Q  pe  r 

A

E

҈

B r

r

O r=R  ᆠE� ᆠ矄矄 ᨨrR  ᆠ矄矄 ᨨR¥

b 㡰 쟼ᆠ�ᆠ � E҈ 盐ᨨ矄鼀矄 ἘAἘQ

쟼ᆠ�ᆠ � E 盐ᨨ���矄 ἘBἘQ

\

rR㡰E㦨

l l ҈ l = =  ⏌  p Î  pÎ  l  = ´ Î p

  pR r҈ ҈  E҈ = pe (  R ) 

졔 졔 졔 졔 졔  졔 졔 졔 졔 졔 졔 졔 ® ® 쟼  쟼҈ 졔 졔 졔 졔 졔 졔 졔 졔  졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 r

s E㦨 2Î

쟼҈ r㡰㦨쟼 r㡰

\

졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔 졔  졔 졔 r҈



E҈ r㡰㦨E r㡰㦨E r㡰 ෌� 㡰 㡰

 r҈ ´ pR r pR r҈ R ҈  ´ ҈ = 㦨   p Î   Î  R㡰   ´



b㡰

ᨨᨨ� ᆠ �쟼㦨

쟼 µ

҈ d

kp



d

�

  ᨨ �ᨨ

a

k l r

҈

쟼㦨  �쟼 µ  d d ᨨ � � �ᨨ �� ᆠ � 쟼㦨

kQ

k l ҈ �쟼 µ d d

k l r





졔l l ᨨ犨ᨨ� � �犨�矄ᆠ泐� �盐 � ᨨ鼀� ᆠ �  矄�泐

쟼㦨

l

l k l k l l k l ´ = ᆠᨨ矄 a 㦨     r d  + l d +l d +l

WWW.JEEBOOKS.IN

EBD_8341 PS-178

Physics

ᨨ E µ

҈ d

Q l s  ) e

rr  =  쟼

盐  ᨨ盐�  ᆠ矄㦨

␔ᨨ├ ᨨ  泐ᆠ�ᆠ � W㦨qv㦨 ( q E ) a ᆠᨨ矄 �o

\

W㦨

 q s҈ - s  㡰 a  e

Topic-3 : Electric Dipole, Electric Flux and Gauss's Law ҈

b㡰 v 矄 ᨨ  �ᨨ 矄� �  �泐ᆠᨨ 矄�ᨨ

K� + U � = K f + U f Þ -

k × p҈ r

҈ ҈ p ᆠᨨ矄 ҈°㡰 = mv  + mv  +   

qE md

㦨쟼ᆠᨨ矄q ᲼␔ q㦨 �犨  �ᨨ  �ᆠ盐ᨨ  � 桌 㦨 ҈黨㡰 ҈㡰ᆠᨨ矄� 㦨䰘䰘맔҈ 㦨䰘맔҈䰘 b㡰 ␔  ᆠ盐�矄ᨨ 矄�  ᨨ� ᆠ �턼�矄 ᆠ  ᨨ    ᆠ盐      ᨨᆠ�ᆠ 盐  盐 ᨨ  �矄 ᆠ � 犨� 矄矄  泐 ᨨ盐�    矄�  ᆠ矄 ᨨ    ᆠ盐 和ᨨ   ᆠ�ᆠ 盐   ᨨ盐�  ᨨ  ᆠ犨�⼄盐ᨨ ҈⏌ ᨨ   ᨨᆠ�ᆠ 盐  盐ᨨ �矄ᆠ �

\ᆠ�ᆠ � E㦨E҈E



=

b㡰



㦨qE맔



�

ᔼ  ᨨ盐鼀ᆠ �  矄�泐�矄ᆠᨨ 矄   쟼µ

㦨

Q ҈ Q ÞE= r³R pe  r  e

b㡰 t㦨PE矄� q ᨨ Ia㦨PE q㡰

a=

ö æ 4π     \ ⼄㦨 çè - ÷ø  ᨨ㦨 ò π    ò

S E㦨

q҈l e

E맔pr㦨



ᔴ ��  矄   鼀  ⼄㦨맔 



®

Ñò E  d A = ᨨ



和盐 ᆠᆠ �  矄�泐  矄ᨨ 泐 盐ᨨ Q꾀矄ᨨ

®



 ᆠ㡰

㡰 b㡰

p ҈ a p Î ma

\ 䰘

턼 Îᨨ

盐  ᨨ盐� ҈ ᆠ㦨

턼  Îᨨ

㡰 T㦨쟼矄� q ᨨ⼄盐 � ᆠ 泐  �ᨨ�  ᆠ�ᆠ r r r �  T = P ´ E

r p 㦨pᆠᨨ矄q �ˆ 졔p 矄� q ˆ r r E҈ = E� r r r T҈ = p ´ E҈ 㦨 pᆠᨨ矄q �ˆ 졔p矄� q ˆ 㡰맔E �ˆ 㡰 t kˆ 㦨pE矄� q  kˆ 㡰  �㡰 r ˆ E =  E҈  r T = p ᆠᨨ矄 q�ˆ + p 矄� qˆ 㡰 ´  E҈ ˆ  ��㡰 tkˆ =  pE҈ ᆠᨨ矄 qkˆ

ᨨ鼀⼄ 矄 �㡰  ��㡰 pE矄� q㦨  pEᆠᨨ矄q  q 㦨 

\

q㦨

WWW.JEEBOOKS.IN

PS-179

Electric Charges and Fields 

黨

(c)   盐 � ├ 犨� ᆠᨨ矄 矄盐 ᆠ矄和҈和和和

҈

҈ ⼄㡰 ᨨ矄盐 ᆠ和҈ f҈ = e ҈ ҈ ⼄ + ⼄ + ⼄ - ⼄㡰 = ⼄ ᨨ矄盐 ᆠ和 f  = e e ҈ ҈ ⼄ + ⼄㡰 = ⼄㡰 ᨨ矄盐 ᆠ和 f = e e ҈ ҈ ⼄ - ⼄ - ⼄㡰 = ⼄㡰 ᨨ矄盐 ᆠ和 f  = e e  ᆠ f҈ 㦨 f 㦨 f 㦨 f �   ᆠ�ᆠ  盐 �矄 矄鼀  ᨨ  矄盐 ᆠ矄 ⧤� 鼀�  ᆠ�ᆠ �  盐ᨨᆠ �ᨨ盐矄�  和 和㡰 ෌盐矄矄� 矄盐 ᆠᆠᨨ �盐矄 ᨨ  盐  ᨨ盐�   矄盐 ᆠᆠ盐矄矄鼀 泐� 矄 盐ᨨ ᆠ �  矄盐 ᆠ 矄� ᆠ㡰 꾀泐� �෌盐矄矄矄 犨 r uur Q Q +  pAr  -  pAa  Ñò S E × ds = Î \ E맔pr㦨 Î

dr dV Q㦨rpr r=

෌盐矄矄�鼀 矄盐 ᆠ



r

A  Q㦨 ò pr dr 㦨pA᲼ra桌 r a

E㦨

ù ҈ é 턼 -  p꾀  +  p꾀 ú ê  p Î ëê  ûú

ᨨEᨨ�   ᨨ �r QpAa 㦨 \A㦨

҈

҈

ᆠ㡰

҈҈

҈ ҈   p Î   ur ᆠ㡰 ෌�  E = E xˆ

졔⼄

� ᆠ � 졔졠 q

  ⏌  ⏌

Nm C f҈f҈҈㦨

⼄

f҈҈ = 

ur  A 㦨a´  a = a

E  a  㡰 ´

҈ 

҈

㡰 盐矄ᆠᨨ 矄� � �鼀 ᨨ  �盐矄  �ᆠ├ 矄矄  和盐 ᆠᆠ �  矄�泐ᨨ  �矄ᆠᨨ  �盐矄 

ö æ s 㡰 = s ç҈ - ÷ è ø

 ö æ s 矄㡰 = s ç ҈ - ÷ è ø

ᔴ �ᨨ  �矄ᆠ鼀 







㡰 쟼 q 꾀 㡰

2





f =



ö æ ⼄ = s ç҈ - ÷ p  è ø

 ö æ ⼄ = s ç҈ - ÷ p  è ø ᨨ犨 ᨨ鼀෌盐矄矄Ἐ矄 ᨨ鼀쟼ᆠ�ᆠ 盐  ᨨ盐� �矄 �ᆠ 矄盐 ᆠ  ᆠᨨ矄矄 ᆠ �  �矄ᆠᆠᨨ鼀泐

q㦨�

㡰

q

\ f҈҈ = é  ´ �ˆ  y  + ҈㡰 ˆ ù �ˆ = ҈ x ë û

ur

㡰

ᆠ泐� 

r uur ᨨ矄盐 ᆠBCGF fn = ò E  dA 

Q 꾀 �犨 쟼 꾀턼㦨� 㡰

҈ a⏌ = a ⏌  

\ f҈ = ò E  A ᆠᨨ矄 黨° = 

� ᆠ�ᆠ �  E  ᆠ矄 ᨨ � 졔 x �ᆠ�ᨨ    �矄 ᆠᨨ 矄 

 ᨨ   ᆠ�ᆠ 盐   ᨨ盐�    矄   ᨨ�ᨨ  犨 ᨨ矄 

㦨Ea

䰘C

\쟼ᆠ�ᆠ 盐 矄矄� � ᨨ盐� 꾀 ᔴ ᆠ泐� �ᆠ矄盐 ᆠ� ᨨ lL  �㦨  ᆠ 㦨 e  ҈� 㡰 r r 盐 ᨨ ᆠ�ᆠ �  E  ᨨ盐�  泐 A �矄  �  矄 f = ò E  A ᆠᨨ矄 q q㦨 �犨 ᆠ�ᆠ �  ᆠᨨᨨ 矄盐 ᆠ ᨨ矄盐 ᆠABCD꾀 �q㦨黨



r r f = E A = EA ᆠᨨ矄 q= E  a  㡰 ᆠᨨ矄 �  㦨

ᨨ鼀 ��盐 q㦨

( ␔  L =  � ᨨ ᆠ泐�  )

=

⼄

C

\ q㦨 쟼ᆠ�ᆠ 盐  ᨨ盐�   ᆠᨨ鼀ᆠ泐� 泐 ෌盐矄矄矄  ᨨ鼀 q �n lL 㦨 fᆠ泐� 㦨 e  e

졔⼄



X C

㡰  盐  ᨨ盐�  ෌盐矄矄� 矄盐 ᆠ�矄 盐ᨨ ᆠ �矄 � 矄�  ෌盐矄矄� 矄盐 ᆠ盐 ᆠ�ᆠ � ᨨ  ෌盐矄矄�

矄盐 ᆠ�矄 ᆠᨨ矄盐鼀ᨨ ᆠ�ᆠ � 矄 盐ᨨ ᆠ �矄 �.e.⼄҈⼄҈ ⼄

҈ 㡰

Q

 pa  ᨨᆠ ᨨ  � ᆠ�ᨨ

Z

q -C f = �n = e e

  턼

Y

㡰 ᨨ鼀   ��盐 ᨨ ᆠ � ᆠᨨ矄 �  ᆠ盐�ᆠ 矄盐 ᆠq� 㦨C졔C䰘C㦨 C 꾀ᆠᆠᨨ � � ᨨ ෌盐矄矄Ἐ矄  ᨨ鼀   ᆠ�ᆠ 盐  ᨨ盐�  ᆠ盐

ò ⼄ = e

æ

 ö

ò s çè҈ - ÷ø p 



e

WWW.JEEBOOKS.IN

EBD_8341 PS-180

Physics

쟼ᆠ�ᆠ 盐  ᨨ盐�  ᨨ 矄 �ᆠ矄盐 ᆠᨨ  �盐矄 ⏌

҈黨

⏌

ö æ s ç ҈ - ÷ p  ø ò ⼄ =  è f= e e

ò

҈䰘

æ  ö   s  p ò ç  - ÷  ç ÷ f ø è   =  =  \ = = ⏌ æ f �    ö s p ò ç  - ÷  ç ÷   ´  ø  è bᆠ㡰 R 㡰 ᨨh>R r㦨

Q  e

 矄ᨨ�  � 矄盐  泐     矄盐 ᆠ  P

R �  = = 䰘° R � é ù Q q�n = Q [҈ - ᆠᨨ矄䰘°] = Q ê҈ - ú = ë �û �

R R �

 ᨨ鼀෌盐矄矄Ἐ矄 ᨨ鼀Q㦨

㡰

҈ ö æ = p (҈  ᆠᨨ矄 q ) = p (҈  ᆠᨨ矄 �° ) = p ç҈ ÷ è ø \ 盐 矄矄� � ᨨ盐� ᆠ盐 矄盐 ᆠ

q�

e

Q \ f = � Î  ᨨh>R r>R



졔Q h

R

f=

R

q�n Q = Î Î

r

ᆠ㡰 ᨨh

R



  R r㦨 R � � q�n = Î

q

R

R �  = =  Þ q = �°  矄� q = R �



é  ù Q q�n = Q [҈ - ᆠᨨ矄 q ] = Q ê҈ - ú = � ë �û \  f =

q  �矄ᆠᆠᨨ � �ᨨ෌盐矄矄Ἐ矄 Î

 ᨨ鼀 졠�ᨨ  㡰   㡰     ᨨ    ᆠ盐盐 犨 �ᆠ  �矄 �  ᨨ� 矄A  Bᆠ盐矄ᆠ�泐�矄��ᆠ ᆠ㡰 쟼ᆠ�ᆠ �  �矄 ᆠ r ᨨ鼀  �矄ᨨ ᆠ泐�  + + l + + E㦨 + + l  pe 

҈ \Eµ  l㦨ᆠ �盐 � � 㡰 

Q � Î

b㡰꾀ᆠᆠᨨ � �ᨨ෌盐矄矄Ἐ矄犨 쟼ᆠ�ᆠ 盐 f

҈ ö æ  p ç҈ ÷ ҈ ö QἘ è Q æ ø ==҈÷ e p e  çè ø ᆠ 㡰 盐ᨨ矄泐鼀鼀泐  ᆠ�ᆠ 盐 矄矄� � ᨨ盐� a x =+   a a z 㦨 + �矄矄鼀 x㦨   꾀ᆠᆠᨨ � � ᨨ ෌盐矄矄Ἐ矄  ᨨ鼀  ᆠ�ᆠ 盐   q�

ᆠ�ᆠ 盐  ᆠᨨ矄矄� �  ᨨ盐�   泐 ᆠᨨ矄  矄盐 ᆠ f 㦨 e - q + q - q q = 㦨  e e ᆠ 㡰

 ᨨ �ᨨ  ᨨ� 矄 � ᨨ   ᆠᨨ 盐ᆠᨨ �矄矄鼀 盐矄 ᨨ �A㦨ᨨ �B

ᨨᆠ�ᆠ 盐  ᨨ盐� ᆠ�泐 =

 ᨨh>R r> R � R �

҈

҈

f=

R R � �

� q

  

矄� q =

q

 졔턼

 ᆠᨨ鼀ᨨ   ᨨ ᆠ�ᆠ �  㜠  �ᆠ盐ᨨ   쟼 쟼ᆠᨨ矄q 矄盐 ᆠ�矄Eᆠᨨ矄q E矄犨矄qᆠ  �矄 ᨨ �  ᨨ� ᨨ   矄盐 ᆠ

ᨨ 盐  ᨨ盐�  ᆠ盐   矄盐 ᆠ矄 ᨨ盐 矄矄





 㡰 ᆠ�ᆠ盐鼀㜠  ᆠ ᨨ     矄盐 ᆠ �矄 

⼄盐�ᨨ �ᆠ盐矄  ᆠ�ᆠ盐鼀  ᆠ �矄 ⼄盐� �矄  ᨨ鼀졔턼

-

+ r

+

+

+

-

Topic-4 : Miscellaneous Problems z

l

҈ ҈ 㦨 ⼄ 㦨 ᲼l맔 矄�  桌 Î � Î



l R 㦨 Î 꾀㦨 矄�  ᨨ꾀ᔴ㦨 矄�  꾀矄ᨨᆠ�ᆠ � �矄 �ᆠ盐ᨨ  犨�   ᨨ �矄 㜠ᆠᨨ鼀 ᨨ   犨� ᨨ

 ᔴ

҈

㡰

 ⼄盐 ᆠ泐ᨨ  和㝐  ᨨ鼀  泐犨ᨨᨨ   ᨨᆠ├





҈

n㦨

҈ p

k  m

졔턼

�矄 盐 ᨨ  ⼄盐 ᆠ泐 犨� 鼀�  盐 ᆠ  � ᆠ盐矄 犨 

ᆠ�ᆠ � �矄矄犨�ᆠ  ᨨ  盐ᨨ ├ 鼀�矄 ᨨ ᆠ QE  鼀  ᨨ矄��ᨨ  ᨨ  和㝐矄 � 矄 ᨨ犨 矄��  泐l㦨 k 盐ᨨ ᨨᆠᆠ� �F㦨qE

WWW.JEEBOOKS.IN

PS-181

Electric Charges and Fields 

㡰  ᆠᨨ矄�ᆠ ᨨᆠ  盐 �  ᆠᨨ矄�ᆠ 矄矄盐   ᨨ�  ᨨ    矄盐 ᆠ ᨨ   盐 � ᨨ鼀泐 ᆠ �



s ҈ e E  =   Î s ´ p  \  ᨨᆠᨨ  鼀�矄 �ᆠ矄 F㦨  Î s R  ᨨ F µ e 矄  =



é kq ҈ ù ᆠᨨ =  +  ê  ´ ú =  ûú a ëê a 和盐 ᆠ 矄�ᨨ  ᨨᆠF矄㦨ga ᔼ ⼄盐���盐鼀

q



a

q

æ q ö a k = ç ÷ \ ç g ÷ è ø ҈㡰 y



├⼄

l Fnet㦨 pe x�fµx 



├⼄





´ ᆠᨨ 矄  㦨 ga

l x \Fnet㦨 pe    d x ␔  xd 

´ ᆠᨨ 矄 

a







├⼄ 

҈⏌ 



x

l éd + x  d + xù \Fnet㦨 pe êë d  - x  úû

㡰 ᆠᨨ矄�ᆠ ᨨᆠᨨ ᨨ ᆠ � 盐ᨨ鼀� � �  ᆠ �矄

kq 



\ N㦨

䰘

p



q x

㡰 l 졔 x0

 ⧤ d 鼀 ᔼ  �ᨨ 矄  ⼄盐���盐鼀 ⧤ ⼄㦨⧤ 졠���  ⼄盐 ᆠ泐 =





 �㡰

l +  㡰 ␔   �矄ᆠ ᨨ犨 矄�� 泐 �    =

⧤ l +  + 㡰

× ⼄ ⧤ 졔 㡰 

鼀 =

x ù ⧤⼄ é ҈+ ú ⧤ x졔x㡰  ê x û l  l + x 㡰 ë 

⧤⼄ é x ù = ҈ú ⧤ x졔x㡰 ê x û l + l + x 㡰 ë

=

⧤⼄ l + x 㡰



⧤ =

é  x ù x + ҈ú ⧤x⧤x = - ⧤ ê l + x l + x  ë û

-⧤ 鼀 ҈ ⧤ ҈ ⧤ 犨 ⼄盐 ᆠ泐 Ἐ = =  = p 鼀 p 鼀 \ d 㦨p㦨҈ 矄 쟼ᆠᨨ矄�ᆠ ᨨᆠ�矄ᆠᨨ 矄��  盐 ᆠ犨ᨨ├ ᨨ �矄   �    꾀矄ἘlἘ�矄 ��鼀㦨⧤  Þ  =

�

ᆠ㡰  ᨨᆠᨨ ᆠ �q犨  ��矄�� 矄鼀 �矄ᆠ鼀  x l l Fnet㦨F҈F 㦨 l l ҈ ҈  졔q F pe d  x pe d + x F҈



x dx d

d � ᆠ �҈

l

� ᆠ �

l

�矄ᆠ鼀    ᨨ q  ᆠ �졔q犨� ᆠ盐和㝐 F ᔼ ᆠ矄ᨨ ᆠ � q㡰F> F҈ F ҈  �.e. ᆠ �  q �矄 盐 矄   ᨨ   ᆠ � q ᆠᨨ � 盐矄 ᨨ 鼀ᨨ�   �ᆠ�ᨨ ᨨ �矄 � ᆠ �҈ � ᆠ � �矄ᆠ鼀  v 㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  盐   � 盐 ᆠᨨ  ᆠᨨ盐ᨨ鼀 ⼄ � ᨨ ᆠ �졔턼ᆠ �q�矄 鼀ᨨ� � ᨨ盐  � �    ��ᆠ 졔Q ᨨ�    �矄 矄�盐�ᨨ  �矄 矄 ᨨ犨

�   ��盐犨 �ᆠ �矄矄�鼀�ᨨ   ᨨ� �ᨨ盐  矄盐   �矄 ᆠᨨ   q ᨨ鼀 졔 Q �矄 ᆠ  �� �  ᨨ ᨨᆠ犨  ᆠ �矄犨�ᆠ  �  矄 ᨨ  ᆠ �q犨��犨   ᆠ ��矄  ᨨ졔Q矄ᆠᨨ鼀 ᨨ犨  ��矄  ᆠ  �盐ᨨᆠ�泐 ᨨ ᆠ �q�矄 ᨨᆠᨨ 矄   �ᆠ�ᨨ ᨨ  ᨨᆠ�泐ᆠ  �矄 ᆠᨨ � 盐ᨨ盐矄泐   ᨨ�  鼀ᨨ鼀 盐鼀�矄 ᨨᆠᨨ 矄    �盐鼀ᨨ鼀 盐鼀ᨨ ᆠ �  q㡰ᨨ盐Q�矄ᆠᨨ 矄 ᆠ盐矄  ᨨ⼄盐ᨨ盐ᆠ �졔Q�矄 ᨨ y ᆠ㡰 Q ᆠ �ᨨ

 � �  ��ᆠ � x Q q �矄矄  ᨨ鼀ᨨ�  P   㡰  ᆠ�ᆠ �   P E 盐ᨨ ᆠ � � �犨� q O z ᨨ � ᨨ矄�� z㜠 �矄   �矄 P  㡰 鼀� �盐 犨� R  Qz ҈  E㦨 pe R + z 㡰⏌

 ᨨ ᨨᆠᨨ ᆠ � P犨�ᨨ犨 矄ᆠ 矄 矄 ᨨ犨   �矄鼀� �盐 �矄 ҈ Qq  Fe㦨qE㦨   ҈㡰 pe R  + Z  㡰⏌  和�鼀�泐 犨  �ᆠᨨ矄矄矄 ᨨ���    ᨨᆠ�矄��  ᨨ犨 矄 ᆠ  O

盐矄   鼀ᨨ�ᨨ  ᨨ    �ᆠ �矄 �ᨨ �ᆠ ᨨ  盐矄 ᨨ  Z  泐� �犨  ¥ 和ᆠᨨ 泐�  ZR R졔 Z  㡰⏌ » R

҈ Qq  Z ᲼ ᨨ鼀⼄盐�ᨨ ҈桌 pe  R   �.e. 矄ᨨ� � ᨨᆠFe µ Z ᆠ 鼀ᨨ�ᨨ ᨨ  �ᆠ 犨�  矄�鼀 鼀ᨨ �ᆠ  �� 矄��  �鼀�矄     ᨨᆠ �矄 ᨨ犨 矄 �矄鼀  ᨨ矄��ᨨ 㡰 Fe㦨

WWW.JEEBOOKS.IN

EBD_8341 PS-182

Physics

Electrostatic Potential and Capacitance

16

ᔴ �ᨨ  �

矄  Q҈ = s pr  ᔴ �ᨨ  ᨨ盐矄  Q = s pR 

Topic-1 : Electrostatic Potential and Equipotential Surface ҈

\ ᨨᆠ � Q = s p r  + R  㡰

KQ  ᆠ㡰 ᨨ � ᆠ  VC = QQ  =  \VC = 

Þs=

ᨨ � ᆠᨨ鼀鼀ᨨ ᆠ 

æ ҈ ö KQ҈ KQ ç 犨  K = ÷ + pe ø r R è K s pr  K spR  + = K sp r + R 㡰  = r R KQp r + R㡰 ҈ r + R 㡰Q =  =    pe  r  + R  㡰 p r + R 㡰 VC =

Eᆠ�ᆠ � ᨨ 盐ᆠ 泐ᆠ ᆠ � ᆠ  

矄盐 ᆠ�ᆠ � 犨� EC 㦨  矄� ᆠ ⼄盐ᆠ�ᆠ � ᆠᨨ矄ᆠ� �⼄盐 �矄ᨨ �矄盐 �矄⼄盐ᨨ ᨨ E

䰘

E

䰘

䰘

E

�

䰘



㡰 ᨨᆠ � Q҈ + Q = Q Ἐ҈ + Q Ἐ

 鼀� �鼀盐鼀 ᨨᆠ�泐 㡰 矄 ᨨ盐  盐矄矄盐 �ᆠ�  ᨨ ᆠ    ᨨ� ᆠ � ᆠ   ᨨ

é ⧤⼄ ⧤⼄ ù ҈ 鼀  = ⼄ ᲼ᔴ -  桌 = ⼄ ê  ë  � úû ⧤⼄   ҈ ⼄  = = ҈�鼀 ҈� pe  鼀

KQ Ἐ҈ KQ Ἐ = 㦨҈㦨黨Ҙᔴ R  R   Q Ἐ҈ = Q Ἐ Þ Q Ἐ + Q Ἐ = 黨mC \ Q Ἐ҈ =  mC   Q Ἐ =  mC

kQ kQ VA = ҈ +  R R

R R

æ

kQ҈ kQ + R R

 ç ├㦨

è

ᨨ � �  ᆠ

DV = VA - VB = 

҈

㡰 ␔ �� 犨ᨨ鼀�ᆠ ᨨᨨ犨矄 矄ᨨ  ��R R � �ᆠ �矄Q҈ Q矄ᆠ�泐 ᨨ �ᨨ  矄盐 ᆠᨨ �

 Q Q҈ 矄   A㡰

VB =



B

ᨨ犨犨  ᆠ �턼�矄 ��  ᨨ ᨨᨨ犨 矄  쟼ᆠ�ᆠ �  犨

矄盐 ᆠ鼀� 盐 ᆠ  � 

҈ ö ÷ pe ø

졔턼 턼

졔턼



졔턼 턼

턼

r KQ E=  r

矄 �  � 矄�   ᨨᨨ犨 矄 �ᆠ 矄 㦨  \ᨨ � �  ᆠ犨  鼀鼀� 盐 ᆠ  �

s

ò

r r

� Edr = V 䰘

C r

㡰 ␔  ᆠ �턼�矄ᨨ  �

矄ᨨ� ᆠᨨ 盐ᆠ� �矄  쟼ᆠ�ᆠ �  犨  矄 �ᆠ矄盐 ᆠ

r KQ r r E =  Sᨨò Edr = V g�ven r

A

㡰 s 矄盐 ᆠᆠ �  矄�泐ᨨ  矄 矄

R

ö  æ ⼄  ç ÷ 鼀 è ҈� ´ pe   ø

Þ  =

Q  kQ҈  × = × ҈ ҈p Î R  R

s

 + 

l =  +  = �

\ V҈ = V =

ᨨ �ᨨ   矄盐 ᆠᨨ ᨨ盐 矄   B㡰

⧤⼄

㦨 㦨

E

 = ҈mC - mC = 黨mC

犨ᨨ�矄ᨨ ᆠᨨ 盐ᆠ� �矄 矄S҈ S ᨨ犨ᆠᨨ

ᆠ 泐 ᆠᨨ 盐ᆠ� �犨�



ᆠ㡰 ᨨ � 泐ᨨ�  ᨨ  ᆠ � � �

 =

䰘 E

Q

p r  + R  㡰

uur

ᆠ㡰 ෌�  E = ( Ax + B ) �ˆ ᨨ E㦨x졔҈

ò

矄� �V = Edx 犨  ҈

VV҈㦨

ò ( x + ҈) dx

-�

㦨҈ᨨ V҈V㦨҈

WWW.JEEBOOKS.IN

PS-183

Electrostatic Potential and Capacitance  黨

b㡰 쟼ᆠ�ᆠᨨ ��矄ᆠᨨ 矄 � 矄� ᆠ � 矄 �ᆠ矄  㡰  �矄 ᆠ�  ᨨ鼀ᨨ� ᨨ   �ᨨ矄ᨨ 盐ᆠ 矄鼀 ᨨ �

⼄

⼄

⼄ ⼄ \ =  ( + )

( )

Þ

 = + Þ =



҈

 ҈

 ᨨ �矄 ᆠ ᨨ鼀꾀犨 �ᆠ  ᨨ  ᨨ  鼀 ᨨ 盐ᆠ  矄鼀 ᨨ �

= ҈

 ҈

+ =

  ҈

b㡰  Q    ᨨᆠ � ᨨ    矄盐 ᆠ ᨨ    矄 �ᆠ 矄   矄盐 ᆠᆠ �  矄�泐�矄

҈

Q 꾀 ᨨ�矄 ᨨ犨ᆠ盐  pR 

ᨨ a p 㡰 ᆠ �ᨨ  �矄 ᨨ矄泐q

⧤⼄ 꾀 ⧤⼄  ⧤⼄ᔴ + +   ᆠ

 =

҈ p Î

 =

s Î

s ᔴ s  s  꾀

é s p  s p  s pᆠ ù + ê ú  ᆠ ûú ëê 

 ᆠ

é   -  ù + ᆠú ê úû ëê 

ᆠ㡰 ᨨ �� �  �矄��  泐 D㦨쟼 㦨쟼  鼀 㡰 D㦨쟼 ᆠᨨ矄q㦨맔ᆠᨨ矄㦨  ᆠ鼀 �鼀盐鼀ᨨ �ᨨ� ᨨ   矄  㦨�黨

-  = ҈    -  S = = ҈ 

b㡰 S҈ =

ᆠᨨ 矄 쟼㡰

\ 矄ᨨ盐ᆠ �矄 � � �泐� ᨨ ᆠᨨ 盐ᆠ� � �ᆠ├ᨨ  �ᆠ├ 矄矄鼀

q Q = \q㦨a턼 Q   a pR 㡰 pR 

r×꾀 µ  e r  㦨 ҈  ᨨ   £ ҈鼀  dv 㡰 꾀矄 犨 ├ ᨨ犨 쟼 㦨  dx \҈ ×҈꾀 =

ᆠ�ᆠ ᨨ � 盐 ᨨ盐 � ᨨ鼀泐ᆠ �  � 矄 �ᆠ 矄  r>R㡰 V =

 =

KQ R ҈

ᨨ �    ᨨ�   㦨 鼀 泐 㦨 鼀 �矄 �� 泐  V

R⏌ P

ò dV = 

M A R



B R ҈�

ᨨ犨  ᨨ �

KQ K aQ KQ 꾀ᨨ� A VA = = ҈ - a 㡰 R R R VP ҈ - a = \ V A ҈ - a

҈

ò

�dx + dy 㡰



ᨨ  矄ᨨ� � 犨 �  㦨  ҈҈ ᨨ ᆠ㡰 ᨨ � �  ᆠ 犨   泐犨ᨨ ᨨ� 矄 �    ᆠ�ᆠ � �矄��  r uur泐 㦨  E × dx VA

KQ K aQ KQ 꾀ᆠ   VP = = ҈ - a 㡰 R R R = V ҈ - a 㡰 = V - aV

 



ò

dV = - ò  x  dx

VO



V A - VO = -᲼҈ x  桌 = - ⏌ ᔴ

ᆠ㡰



ᆠᨨ矄q q ᔴ 矄� q ⼄ x  q



Eᆠ�ᆠ �

KQ  R㡰  KQ K aQ㡰 KQ = - aV ( EB ) �  = R 㡰  R 㡰 R K aQ㡰 aV ( EP )� �� =    ( EP ) �  = R  = R ⧤턼 b㡰 ᨨ � ᨨ盐矄�    矄  ᨨ盐矄�  = 

( EB )� �� =

҈҈

犨 �矄 �矄 ᆠᨨ ᨨ�  ᨨ鼀 ᆠ ᨨ 矄  ᨨ �� 矄�   矄  � 矄�  犨 � �矄 �盐矄ᨨ  矄 

⧤턼 =

鼀� ᔼ ⼄盐���盐鼀  = 矄� q 鼀�㦨 ᆠᨨ矄 q

 q =

 ⼄ = = 鼀� p Î  ´ 鼀� \

⼄ p Î  q 鼀�

쟼ᆠ�ᆠᨨ � ᆠ ᨨ  � 

= ҈䰘

├⼄ ├⼄ + =  ├鼀� ⏌  q ⏌ ⏌

㡰 꾀ᆠᆠᨨ � � ᨨ ෌盐矄矄Ἐ矄  ᨨ鼀 ᆠ�ᆠ � 犨  犨ᨨ

l  �矄ᆠ�ᆠ � 犨�ᨨ 盐ᆠᨨ � peurr r �  ᆠ矄dV㦨 Ed r ␔  ᆠ �  矄�泐�矄�� ᨨ 

ᆠ泐� 矄 E =



 ᆠ泐�  ᨨ � ᨨ �矄 矄盐 ᆠ�矄 �  

WWW.JEEBOOKS.IN

EBD_8341 PS-184

҈

Physics

ᨨ鼀   ᨨ    ᨨ盐 ᆠ泐�  �矄 �矄 ᆠ盐矄  ᨨ � ᆠ矄矄犨�  �矄 ᆠ ᨨᆠ � ᆠᨨ 盐ᆠ� �ᆠ泐� 犨 

  ᨨ�  ᨨ  ᆠᨨ 矄� �ᨨ  �矄 ᨨ盐矄�    ᆠ泐�  盐犨  ᆠ �  矄�泐�矄�� ᨨ ᨨ盐ᆠ泐� �犨� ᆠ  � �矄 ᨨ � 泐  矄鼀 鼀ᨨ盐  矄   ᨨ    �

 ᆠ泐�  ᆠ ᨨᨨ � �  ᆠ犨�ᨨ 盐ᆠ 犨

  ᆠ泐� 矄 b㡰 꾀矄犨鼀ᨨᨨ �  �ᆠ�ᨨ ᨨ ᆠ�ᆠ �  ᨨ � ᆠ矄矄 \ VA>VB  VA㦨VCᨨ ⼄盐�ᨨ �矄盐 ᆠ



dv dt qEdt q 矄� ҈t �ˆ dt Þ 㦨 㦨 m m  Q 쟼㦨矄� ҈  �ˆ �� 㡰

㡰

v

\ ò dv = 



҈㡰







҈㡰 



\

㡰  ᨨ � �  ᆠ ᆠᨨ矄矄 ᆠᆠ�ᨨ 矄 鼀� 矄 盐 ᆠ  � 犨  矄犨�ᆠ S�矄ᆠᨨ矄 ␔�  ᆠᨨ矄� �ᨨ 矄犨�ᆠ S   S ҈   �� ᆠ � ᨨ  C  犨� ᆠ   ᨨ矄�� ᆠ �ᨨ C 泐鼀� � � �  ��ᆠ �ᨨ C҈ 

��ᆠ �ᨨ C҈犨�ᆠ ᨨ矄��ᆠ �ᨨ C҈ᨨ  矄 ᨨ ᆠ �犨�├ᆠ  ᨨ ᆠᨨ矄矄C҈ C 犨� 矄ᆠ�泐 㡰 ᨨ � ᨨ��� 犨���  泐

�



  㦨맔҈⏌鼀 = ҈

p⏌ w

҈ ҈

´ 

᲼ᆠᨨ矄҈t 桌p ⏌ w ҈

é ë



p ù  ᆠᨨ矄  ú 㦨᲼҈҈桌㦨鼀矄҈ ҈ û

d  x  㡰 -dV = - x  Þ Ex㦨 dx dx

ᆠ�ᆠ � ᨨ�  ҈㡰 x㦨҈㡰 Ex 㦨⏌鼀

鼀� �盐 ᨨ ᆠ�ᆠ � �矄�矄ᨨ� Bᆠ盐矄B   ⼄盐�ᨨ � 矄盐 ᆠ矄  ᆠᨨ矄矄 ᆠ 㡰 쟼ᆠᨨ矄�ᆠ � P �矄 P

r ᔴ҈

ur ur ur r uuuur (  r) uuuur E p = E҈ + E  = C҈ P + C P e  e  r uuuur uuuur r uuuur uuuur r uuuuur = C҈ P  C P = C҈ P + PC = C҈C e e e bᆠ㡰uuur uuur uuur  E D  uuur uuur  E A  uuur =  EB  =  EC  = =  E E  =  EF  = K   

(



\

)

(

졔q F 졔q A

㦨҈鼀

E q

(

)

҈ ҈ 졔 ⧤졔⧤㡰맔 㦨⧤  

q D

O

鼀� q

졔q B

C

EB 졔 EE

 꾀矄⼄㦨   鼀 = p r  \ 맔҈맔҈҈黨맔맔҈

p 맔҈䰘㡰맔黨맔҈    ´҈ -䰘 㡰 ´ 黨 ´҈ Þ = p´ \ 㦨   ´ ҈  ´ ҈ ´ ҈ -҈黨

)

EO㦨EA졔ED 졔 EF졔 EC㡰ᆠᨨ矄º졔 EB 졔 EC㡰ᆠᨨ矄º

㦨⧤졔⧤졔 ⧤졔⧤㡰맔

和犨�ᆠ

–r ᔴ 

҈

쟼⼄

=

㦨 

 ᆠ鼀 �鼀盐鼀 矄 �  泐 �ᆠ ෌�  ᆠ�ᆠᨨ �V 㦨 x ᨨ矄

 ᨨᆠ�ᆠᨨ �ᆠ  �矄 ᨨ 泐ᨨ �x㜠 �矄

␔   鼀� ᨨᆠ�泐�矄ᆠ � ⼄쟼㦨鼀�

㦨

T p ù é 矄� ҈t dt ê 鼀  矄 �矄  =  w´  úû ë

㦨  êᆠᨨ矄҈ ´

␔├ ᨨ犨Ex㦨

䰘

㡰  ᨨ �� 矄�   矄 �矄⼄盐ᨨ  ᨨ �ᨨ  �矄 矄盐 ᆠ␔  犨 Qᆠ �ᨨ  矄盐 ᆠ ᨨ �ᨨ   矄盐 ᆠᆠ  �矄泐 矄鼀鼀ᨨ盐  矄 � 矄�   ᨨ   ᨨ � �  ᆠ鼀� 矄 矄鼀 v㡰 b㡰 ᆠ�ᆠᨨ � 矄盐 ᆠᨨ  ᨨᨨ犨ᨨᆠᨨ 盐ᆠ� � 矄  �矄 矄鼀 矄   ᨨ �    ᆠ  ᨨ    矄    泐 ᨨ�  � 矄�    矄   ᆠ ᆠ�ᆠ ᨨ � 矄盐 ᆠ ᨨ    矄  㦨 ᨨ � ᆠ ᨨ  矄 㦨҈ 㡰   ᨨ ᨨ ᆠᨨ 矄矄 �   ᨨ� ᨨ 쟼ᆠ�ᆠ �  쟼 =

ò

æQ m = ҈ kg  q = ҈C  E = ҈NC ҈ ö ç ÷ ç and w = ҈  矄҈ ��

÷ è ø

ù ҈ ҈ ҈ q é҈ + + ú V㦨 ê pe  ë x  x x  x û q  㡰 V㦨 pe  x ҈

p⏌w





҈黨

q m

q é ᆠᨨ矄҈t ù \ 㦨  ê m ë ҈ úû 



㡰 꾀

Q  㦨鼀\⼄쟼㦨 m

º O

º

EA

ED

EF 졔 EC



WWW.JEEBOOKS.IN

PS-185

Electrostatic Potential and Capacitance

( )

쟼ᆠ�ᆠ ᨨ � O

 \ pR = pa t Þ R = a t 

҈ VO㦨 ᲼q졔q졔qqqq桌㦨 p e L

黨



҈ QA ҈ QB \ = =V p Î RA p Î RB Q RA>RB\ QA>AB

sA s   EB = B Î Î E A s A RB = = < ҈ \ 쟼 쟼 꾀  EB s B RA V

졔졔졔졔 졔 졔졔 졔



졔졔졔졔졔졔졔 졔

R

R

r

졔졔졔졔졔 졔졔 졔 졔

ᨨ �ᨨ  �⼄盐� 盐 V =

㡰 Pᨨ� �  X㜠Y 犨� ᆠᨨᨨ � 矄 x, y㡰 犨 �ᆠ    ᨨ � 盐 ᨨ ᆠ �矄  Q ᨨᆠ   a㡰 졔Q ᨨᆠ 졔㡰 ᨨ Y

P x y㡰

y

y A 㜠Q X' 㜠a㡰 O x a 졔x㡰

Y'

K Q 㡰 

V 㦨 a �a  黨ax  a

B 졔Q C X a㡰 �a㡰 a㜠x㡰



=

K +Q㡰 a - x㡰  + y 

K -Q㡰 K +Q㡰 ҈ + 犨 k㦨 x + a x - a㡰 pe  ù é ҈ \ V x㡰㦨KQ ê  ᨨx>a ë x - a x + a úû V x㡰㦨

졔졔졔졔 졔 졔졔 졔



Q Q = C pe  R



ᨨ � M

㡰 ᨨrR ᨨ ��矄 E ᆠᨨ 矄   ᆠ�ᆠ�  矄�泐 �矄 ᨨ 졠�ᨨ盐矄泐   ᆠᨨ矄�ᆠ �泐�矄 ᨨ ᨨr R  R r b㡰  �矄盐矄 矄  ᆠ ᨨᨨ �� ᆠ�ᆠ ᆠ�ᆠ盐�矄 ᨨ ᆠ�ᆠ 盐ᨨ矄矄 ᨨ 矄 �ᆠ ᆠᆠ�ᨨ ᆠᆠ� ᆠ ᔴ 㦨 peR   ᆠ�ᆠ ᨨ � V =



҈

�矄�矄 ⼄盐�ᨨ ᨨ ᆠ�ᆠ犨� ᆠ  �a㡰  �盐矄a b㡰 ᨨxa 盐矄 ᆠᨨ 矄�  ᨨ�  �泐㡰 M  �矄 ᆠ x ᨨ鼀   ᨨ��� ᨨ x㜠 �矄

RB RA

㡰 E A =





æ aö =Vç ÷ è t ø

Þ  a - x㡰 + y  = a + x㡰  + y  Þ x�a㡰졔 y㡰㦨 a㡰

A

b 㡰

�� V㜠r� �矄ᨨ ᆠ � ᆠᨨ 盐ᆠ� �矄  ᨨ   �盐矄  㡰 犨 ᨨᆠ � Q 犨�   ᆠᨨ矄  �   矄  ᨨ �鼀R 㡰 쟼ᆠ�ᆠ � E 㦨 ᨨ� 矄�    矄   ᆠ ᆠ�ᆠ � �矄 �矄ᆠᨨ � 盐 r㦨R ᆠ㡰 ᔴ  �矄 �     E  ᆠᨨ � 盐ᨨ盐矄泐矄  ᨨr>R  졠�ᨨ  ᆠ㡰 �矄 � ᆠᨨᆠ



(a t )

҈

a + x㡰 + y

QA

҈

æ Va ö Kç ÷ è kø

Kq V҈ = = R

\

 R R  pÎ 꾀V  pR A Q s = B´ A= B´ ᆠ㡰 꾀矄 A = 㦨  Q sB B R QB R   p Î RBV A



ᨨ � ᨨ    ᨨ

ᨨ �ᨨ� 矄ᨨ  �  �矄矄鼀 ᨨᨨ � 和  PR �矄  �ᆠ盐 �矄ᆠᨨ   ⼄盐ᨨ�� 㡰 ᨨ   ᆠ�ᆠ �ᨨ矄ABFE BC  ᨨ  ᆠ�ᆠᨨ �犨� ᨨ  泐ᨨ� ᨨ  PR ᆠ 㡰 㡰 ෌盐矄矄Ἐ矄犨 �矄�  ᨨ 泐犨   쟼 µ  㡰 ෌盐矄矄Ἐ矄犨ᆠ

ᨨ盐矄 ᨨᆠᆠ盐  �  �矄�盐�ᨨ

ᨨ盐   ᆠ�ᆠ �ᨨ ᆠ㡰 �矄 ᆠᨨᆠ 矄 犨  犨ᨨ ᨨ�  ᆠ �矄 犨 犨� �  ᨨ� 犨  ᆠ�ᆠ �  盐ᨨ 犨ᨨᨨ� ᆠ �矄ᆠ ᆠ ᨨ盐ᆠ ᨨ ᔼ 犨ᨨᨨ� ᆠ �矄ᨨ ᨨᨨ矄�矄��     犨ᨨ � 矄ᨨ �   �ᆠ�ᨨ   ᆠ 泐ᆠ

ᨨ ᨨ 㡰 WAB㦨q DV㡰㦨҈ VBVA㡰 ᨨWAB㦨VBVA bᆠ 㡰 㡰 쟼ᆠ�ᆠ � � 矄� 矄 �ᆠ鼀�ᆠ矄 犨� ᆠ �ᨨ

 矄盐 ᆠ�矄犨泐矄 ᨨ �.e.EA� 矄� 㦨 㡰 ␔    矄 矄ᆠᨨ

ᆠ 犨�   � 鼀犨� 

ᆠ�ᆠᨨ �矄犨�⼄盐�.e.VA㦨VB㦨V

  pRB

҈

和�鼀�泐 ᨨxa

 ù é ҈ ë a - x a + x úû

V x㡰㦨KQ ê

和� ᆠᆠ�ᆠᨨ  ᨨᨨ �ᆠ盐矄 x㜠 �矄 a㡰  黨a㡰  ᆠV x㡰㦨x㦨ax㦨黨a 掸 ᨨ鼀   ᨨ  矄矄�ᨨ 矄 V x㡰®¥x®a V x㡰®¥x®a 掸 V x㡰®矄x® ±¥ 掸

V x㡰�矄

҈ � �  x

盐 ᆠ�ᨨ  x㡰ᨨ  犨 ᨨx �矄矄矄 ᨨ犨 ᨨ犨 V

a a

a

黨a

x

kq Va Þq= a K

␔  q 㦨ᆠ �ᨨ  �⼄盐� 盐    ᆠᨨ矄� �    �盐矄 ᨨ  ᨨ ᆠᨨ鼀矄 R 盐  ᨨ盐鼀 鼀� 矄 ᆠᨨ 矄 

WWW.JEEBOOKS.IN

EBD_8341 PS-186

Physics \ ᨨᨨ �  ᆠᨨ鼀鼀ᨨ ᆠ �졠

ᆠ㡰 ᨨ鼀  �泐ᆠᨨ 矄�ᨨ  � ᆠ� v  矄 ᨨ �ᆠ ⧤쟼졔쟼㡰ᆠ 㦨 ⧤쟼졔 쟼㡰ᆠ�ᆠ盐鼀  ᆠ

V㦨V�졔V㦨

é Qq Qq ù ҈  é Qq Qq ù = mv + K ê 졔K ê ú  a  a  ë û ë a ҈a úû ҈  KQq \ v㦨 mv =  a �

KQq =  ma

҈ æ Qq ö ç ÷  pe  è  ma ø

҈

KQR 

R +r

 㦨

kq A kqB kqC + + a b c

q



kq A kqB kqC s + + ᨨ VB㦨 b b c e

é a ù ê - b + cú êë b úû

矄�� 矄 ᨨ犨矄  �泐ᨨ  ᆠ ��矄 ᆠ矄� � ᆠ㡰 꾀ᆠᆠᨨ � �ᨨ犨ᨨ├ �泐 ᨨ鼀�� � ├� �ᆠ �泐�矄 ⼄盐ᨨ犨ᨨ├ ᨨ �  �矄ᆠ鼀 ᨨ ᆠ �

\



m



v  = =  ҈ v ҈ é ù ê ҈ - q 㡰Q ú q - q㡰 qQ ê ú 㡰 U = + + dö æ dö ú  p Î ê d æ çè D + ÷ø çè D - ÷ø ú êë   û  é ù  q qQd ҈ = -  ú ᔼ� ᨨ� � d êp Î ëê d D ûú 



b㡰  ᆠᨨ矄�ᆠ  �泐 ᨨ   矄泐矄鼀

pR 

qR㦨Qrqr

æ q = ᆠ �ᨨ �

矄  ö \ q㦨    çè Q q 㦨ᆠ �ᨨ ᨨ盐矄  ÷ø R +r

é ⼄ 턼⼄ 턼⼄ ù  = ⧤ê + + =     úú ëê û

Qr 

ᨨ �O 盐ᨨ�

矄 



é ҈ ù Þ ⼄ = -턼 ê҈ + ú    ë û

æ ö q = K ç Qr ÷    ç r è R + r ÷ø r Qr 

V�㦨 K

҈

\

qö æ çè 和盐 ᆠ ᆠ �  矄�泐s = ÷ø A

V�㦨 K

҈  mv = q DV 

㝐矄矄ᨨ  泐 ᨨ�  �ᨨ 鼀 㦨҈ 㝐矄矄ᨨ  �盐鼀�ᨨ 鼀 㦨

Q-q

ᨨ qR㦨 Qq㡰r ᨨ

Þ턼=

R + r 

ᨨ � O 盐 ᨨ ᨨ盐 矄   ù é Q - q㡰 = K êQ - Qr ú V㦨 K  R  R + r  ûú ëê R

-⼄  졔҈

졠㡰 턼

�

 ù  é  KQR K ( QR ) K ëQR + Qr - Qr û = 㦨 㦨   R + r  R R + r 㡰 R R + r 

(

d

DV㦨ᨨ � �  ᆠ犨 犨ᨨᨨ矄��ᨨ 矄ᨨ ᆠ �q ᨨ矄鼀q DV.

ᨨ acbc졔c㦨ab졔cᨨc㦨a졔 b ෌� 矄盐 ᆠᆠ �  矄��矄⼄盐

pr 

d⏌

q  æ k q k q ö Du = q ç =÷ è d ⏌  d ⏌  ø pe  d

kq A kq B kqC + + c c c   ù é s a -b +c ᨨVC㦨 ê ú e  ëê c ûú 㡰 Q VA = VC  �� 㡰 s s é a  - b + c  ù a - b + c 㡰 = ê ú c e e  ëê ûú

=

R + r 

X

q

O

d⏌

꾀 VC㦨

q

KQ R + r 㡰

q

s ᲼ a - b + c桌 e

和�鼀�泐VB㦨

\

+

Y

҈  pa  ҈ pb  㡰 ҈  pc  㡰 ´s´ s + ´s 㦨 a b c pe pe  pe 



R +r



㡰 ᔴ  �� ᨨ � �泐 Du = q V f - V� 㡰 ᨨ �ᨨ  q�矄矄鼀矄� ��  � ᨨ� ᨨ   

 k s  p a  㡰 k ( -s )  pb 㡰 k s  pc  㡰 + + 㦨 a b c

㦨



Topic-2 : Electric Potential Energy and Work Done in Carrying a Charge

ᨨ � 泐矄 �矄 盐ᆠ �矄 矄 꾀 ᔴ ᨨ �ᨨ 矄 A VA 㦨

KQr

) (

)

졔⼄

  

졔⼄

턼 졔㡰

b㡰 졠㡰 턼

턼 㡰

ᨨ �  ᨨ���

WWW.JEEBOOKS.IN

PS-187

Electrostatic Potential and Capacitance

⧤턼 ⧤턼 ⧤턼 ⧤턼 + + +     ҈ ö æ  ᨨ �¥㦨㦨⧤턼 ç ҈+ ÷ �ø è

㦨

q

�   �泐

\ ␔ᨨ├ ⼄盐� ᨨ 盐   �  ᆠ � 턼  ᨨ��� ␔ 㦨 턼

ᆠ㡰 犨ᨨ├ ᨨ � 鼀ᨨ� �ᆠ �ᨨ �  ⼄盐�ᨨ � 矄盐 ᆠ �矄 犨泐矄 ᨨ

 �ᆠ�ᨨ ᨨ ᆠ�ᆠ � �矄 �ᆠ盐ᨨ ⼄盐�ᨨ � 矄盐 ᆠᨨ� 矄

䰘

ᆠ㡰 㡰 ᆠ�ᆠ �  盐ᨨᆠ �

æ q ö çè ÷  ø

꾀矄ᨨ

º

⼄  

҈



҈҈

ᔴ 꾀 㦨矄� ºÞᔴ㦨 㦨  꾀 

é( ⼄ ⏌ )( ⏌ ) ù é ( ⼄⏌)( -⼄ ⏌ ) ù é( ⼄⏌)( -⼄ ⏌ ) ù ú+⧤ê ú +⧤ê ú   ë û ë û ë û ├⼄  é ҈  ù -㦨 ú ¹ 黨 êë  û ê

ᆠ㡰 㝐� �盐 ᨨ  ᨨᆠ犨  ᔴ

(

)

҈

é +q ⏌  ù é +q ⏌  ù é -q ⏌  ù 졔⧤ ê 졔⧤ ê 㦨 ú ú ë û ë û ë úû

)

)

)

Qq q  Qq + + = a a a 

ᨨ

Q  + q  + Q =  \ Q㦨 -

q   +҈

=-

q

+ 

b㡰 㡰 ᨨdxd ᆠ�ᆠ � �矄ᨨ �졔x㜠 �矄 ᨨᨨ ᨨ� 矄쟼�矄ᨨ � ��x㜠 �矄 泐 쟼  ᆠ쟼犨� ᨨ 矄鼀 �ᆠ�ᨨ

졔q㡰 ᨨ � �x㜠 �矄  쟼 㡰 쟼ᆠ�ᆠ � Pᨨ� ᨨ

쟼 q㡰 泐㜠 �矄 �矄 ᨨ x㜠 �矄 ᔼ �矄 ᨨ ᨨ �x㜠 �矄�矄  ᆠ㡰 쟼ᆠ�ᆠ ᨨ �  q 졔q x ᨨ��� 㦨 ᨨ d㡰 㡰 d㡰 ᨨ犨ᨨ├ 矄ᨨ ᨨ � � �� �矄ᆠ � ᨨ鼀� � �泐ᨨ  ᨨ���  㡰  �ᨨ鼀ᨨ鼀 �矄 �ᆠ  ᨨ鼀qᆠ �ᨨ졔qᆠ � ᨨ � �� �ᆠ�ᨨ ᨨ x㜠 �矄 \�ᨨ鼀ᨨ鼀 㦨qdᨨ �x㜠 �矄 b㡰 犨ᨨ├ ᨨ � 鼀ᨨ� �ᆠ �q ᨨ鼀ᆠ ᨨ ᨨ � � ᨨᨨ 㦨ᆠ  �� ᨨ � �泐 Q҈

㡰 ᨨ �졠㦨⧤ ê 

(

\



⼄ ҈ ( ⼄ ⏌ )( ⼄ ⏌ )  㦨  4π Îᨨ �π Îᨨ  

ax � 泐

b㡰 和� ᆠ ᆠᨨ矄�ᆠ �泐㦨



㡰 ᨨ �  �泐ᨨ    矄泐矄鼀 ⧤



Qq pe 

(

 졠 犨�� ᆠ ᆠ  ᆠ�ᆠ �  O 盐ᨨᆠ �

q ҈ q ⏌  㦨  4π Îᨨ R   π Îᨨ  꾀ᔴ - ⼄ ᔴ ᔼ D꾀ᔴ 㦨矄� º 꾀  º 꾀 꾀 ⼄ Þ꾀ᔴ㦨 㦨   

x a졔x 

(

q q 꾀 ᆠ �   

쟼=



q

Qqa ҈ ù+ ҈ q = é ҈ êë a + x + a - x úû pe  a pe a  - x   é ù Qq ê ҈ a ú U - Uf = \ � pe  ê a a  - x  ú ëê ûú é   ù Qq ê a - x - a ú -Qqx = = pe  ê a a  - x  ú pe a  ëê ûú  犨   x ҈桌 犨ᆠ �㦨KCV 犨 ᨨ �  �泐 㦨

V d

҈ KCV 

E㦨

矄鼀ᆠᆠ� ᆠᨨ   ᨨ ᨨ�ᨨ 

V d

�㡰  ᨨ盐 ᆠ � ᆠᆠ�ᨨ 矄 ᔴ �ᨨ ᆠᆠ�ᨨA qA㦨맔҈맔҈㦨맔҈ᔴ ᔴ �ᨨ ᆠᆠ�ᨨ B qB㦨맔҈맔҈㦨맔҈ᔴ ␔  盐 ᆠ � ᆠᆠ�ᨨ 矄  ᆠ �ᨨ ᆠᆠ�ᨨAC B  q҈ q   q 矄ᆠ�泐 泐ᆠ � ᆠᨨ 矄�ᨨ 

҈ ҈ ҈ = + dC dC҈ dC

犨 dC҈㦨 ᆠᆠ� ᆠᨨ ᆠᆠ�ᨨ犨�  �ᆠ�ᆠK҈ dC 㦨ᆠᆠ� ᆠ ᨨ  ᆠᆠ�ᨨ 犨�  �ᆠ�ᆠ K + + +

A

m q҈

҈

+ + +

K҈ bdx 㡰 e  dἘ d é xù d'㦨dx = d ê҈ - ú l ë lû

dC҈㦨

B

m q ҈

\

dC҈㦨

K҈ A e ( dx) K҈b ( dx) e  K҈bl ( dx) e = d l - x 㡰 d l - x 㡰 é xù d ê҈ - ú ë lû

WWW.JEEBOOKS.IN

PS-197

Electrostatic Potential and Capacitance

和�鼀�泐dC㦨

K  e  bdx 㡰 K  e bdx = xd d -dἘ d -d + l

㦨

㦨

K  e  bldx K  e Adx = xd xd \

҈ d l - x 㡰 xd = + dC K҈ Ae  ( dx ) K  Ae  ( dx )

Þ

K҈K  A e dx = dC K  ld + d K҈ - K  㡰 x

l

dx

ò K ld + d K҈ - K 㡰 x

CAἘ㦨

l

é ᨨ�᲼ K  ld + d K҈ - K  㡰 x桌 ù ú d K҈ - K  㡰 ë û

�

Ae  ´ � ´ ҈ -҈ = 㦨맔҈黨F d � ´ ҈-

q㦨CAV㦨맔҈黨맔҈҈㦨맔҈䰘C \

K҈ K  Ae K ᨨ� ҈ d K҈ - K  㡰 K

W㦨

ù  ´ ҈-䰘 㡰 é ҈ ҈ ê -黨 -黨 ú   ´ ҈ û ë  ´ ҈

ᨨW㦨맔҈�

e  e r AB d

  矄泐矄鼀 矄矄 ᨨ犨  �    ��盐矄 �矄 ⼄盐� ᨨ 犨ᨨ ᆠᆠ�ᨨ矄� ᨨ 犨� � ᨨ 犨� ᨨ�犨�  �ᆠ�ᆠ C㦨C҈졔C

���㡰 ᔴᆠ� ᆠᨨ B㦨

k e  x ´ ҈㡰 e ᲼ ҈ - x 㡰 ´ ҈㡰 + 㦨  d d

㦨

e ᲼kx + ҈ - x桌 C㦨 d

ᔴ �ᨨ AqA㦨맔҈䰘 C�矄 �矄�盐 � ᨨ犨ᨨ矄 \ q҈졔q㦨맔҈䰘C 꾀矄ᨨ ᨨ � �  ᆠᆠᨨ矄矄A㦨  ᆠᨨ矄矄 B

 �㡰

x㦨矄� ᨨ   �ᆠ�ᆠ㦨҈m d㦨҈m

和ᨨ I =

\

A ᨨ犨ᆠᆠ� ᆠ CA㦨C҈졔C

 ´ ҈-䰘 㦨҈맔҈䰘C ҈

ᨨ �泐矄ᨨ  㦨

㦨

+

+ - A⏌ A⏌ -

 ´ ҈-黨 CA q 㦨q q㦨 CB ҈ ´ ҈-黨 

Þ q҈㦨맔҈䰘C

A ᆠᆠ�ᨨ矄�   ᨨ  � � �ᆠ�ᆠ 矄     A  ᨨ ᨨ �矄犨� ᨨ盐 �ᆠ�ᆠ矄    +

㦨҈맔҈黨F

q졔q㦨맔҈䰘

Þ q㦨

�㡰 ᆠᆠ�ᨨA犨�  �ᆠ�ᆠ矄ᆠ ᆠᨨ 矄�  矄犨ᨨ

҈҈

� ´ ҈-

Þ q҈㦨

� ´ ҈ ҈ ´ � [҈҈  ҈] ´ ҈ = � ´ ҈ 黨 A ҈

+ + +

� ´ ҈-҈ ´ 黨 ´ 

q҈ q =  C Ἐ A CB

e V \ q = CV =  ëé҈ + x ( K  ҈)ûù ҈ dq e V dx = [ K  ҈] \ᔴ盐  I = dt ҈ dt

�䰘

҈ ҈ C V 㦨 맔맔҈黨맔 ҈҈㡰  A 

q q W㦨 C A Ἐ C A

㦨K҈KAe ê

ᨨC㦨

᲼҈ + 黨桌 㦨맔҈黨F

㦨҈҈맔҈� ��㡰 ␔ �├� �ᨨ盐  �ᆠ�ᆠ ᆠ �ᨨ  ᆠᆠ�ᨨ  鼀� 矄   矄鼀 盐 ᆠᆠ� ᆠ ᨨ 꾀犨� � ᆠ  �   ᆠ �泐犨�ᆠ  � �矄ᆠ  ��  �泐�矄⼄盐ᨨ犨ᨨ├ ᨨ 

ò K ld + d K҈ - K 㡰 x

㦨K҈KAe

 ´ � ´ ҈-

UA㦨

K҈ K  Ae  dx

l

 ´ � ´ ҈-҈

쟼 �泐矄ᨨ �  �矄ᆠᆠ�ᨨ犨  ᆠᨨ

ᆠ ᨨV㦨҈҈ᨨ 泐

 ᆠᆠᆠ� ᆠ ᨨ   犨 ᨨᆠᆠ�ᨨ C㦨

A ⏌ 㡰 e A ⏌ 㡰 e  er A e  + = ᲼҈ + e r 桌 d d  d

 ´  ´ ҈-҈  ´  ´ ҈-黨

+

q҈ q +  C Ἐ A CB

҈ ´ ҈ ´ ҈-҈  ´ ҈ ´ ҈-

㦨맔҈�졔黨맔҈�㦨҈҈맔҈� �

ᨨ � �  ᆠᆠᨨ矄矄ᆠ ᆠᆠ�ᨨ�矄V矄ᨨ ᆠᆠ�ᨨ矄 � 

ᨨ �泐㦨 �泐� A졔 �泐� B

WWW.JEEBOOKS.IN

EBD_8341 PS-198

㦨

Physics

҈ ҈ CV  + CV  㦨CV  

 �㡰

␔   矄犨�ᆠ ᨨ    �ᆠ�ᆠ�矄� 矄 犨   矄 ᨨ  ᆠᆠ�ᨨ矄   犨 ᆠᆠ� ᆠ �矄 ᔴ 盐 ᨨ � �  ᆠᆠᨨ矄矄��矄V 쟼 �泐� A㦨

҈  C 㡰V   = CV   

쟼 �泐� B㦨

CV  ҈ q ҈ CV 㡰  = ´ 㦨  KC  C 



ᆠ �ᨨ ᆠᆠ�ᨨB鼀� 矄矄鼀犨  矄犨�ᆠ �矄ᨨ  㡰  ᨨ �泐㦨 �泐� A졔 �泐� B \

ᨨ �泐㦨

 ҈ � CV  + CV  = CV    

 ��㡰

ᨨ  �泐 � ��泐  CV  = = �

ᨨ  �泐 � 泐 � CV  

\ \

V=

쟼ᆠ�ᆠ �  盐ᨨ �

鼀ᨨ矄ᨨ矄��  ��ᆠ �矄

é

qù ú ᨨ犨 矄  ë r û

M E҈ =  ê k

é q ù E =  ê k  ᨨ犨 矄 ��  쟼ᆠ�ᆠ �  盐 ᨨ ú ëê r 㡰 ûú  ᨨ盐鼀ᨨ矄ᨨ矄��  ��ᆠ �矄 M

ᆠ㡰 꾀ᆠᆠᨨ � �ᨨ ⼄盐矄�ᨨ ᨨᨨ  �矄矄 矄鼀� 㜠 犨泐犨    犨ᨨ矄  �矄 ᨨ盐 ᨨ 鼀ᨨ  �  矄ᨨ

 ᨨᆠ �矄 �  ᨨ鼀 �ᆠ 犨ᨨ ᨨᆠ矄ᆠ� �ᨨ   qE 졔 ᨨᨨ 盐矄   矄矄 q 㦨� 矄 ᨨ犨 �   ��盐 qE㦨mg

æV ö q ç ÷ = mg èdø

 졔  졔  졔 㝐 턼

쟼ᆠ�ᆠ �  盐 ᨨ   ᨨ矄��  �� ᆠ �矄M

Topic-4 : Miscellaneous (Mixed Concepts) Problems ҈

ᆠ�ᆠᨨ � 盐ᨨ ᆠ �矄M �矄 ᨨ �㦨㝐 ␔     矄泐矄鼀 ᨨ  ᆠ �矄 �矄 ᨨ  ᨨ盐 �  PM    ᆠ盐 犨� ᨨ  ᆠ鼀� �ᆠ � B㦨M. ␔  B㦨  m㦨 ⼄㡰 㝐 �矄   鼀� 㜠ᨨ�  犨    犨ᨨ �

鼀ᨨ矄 ᆠ �矄

v

mg

mgd ҈䰘 ´ ҈-䰘 ´ ҈ ´҈ - = ҈-黨  㦨 -҈黨 q ҈ ´ ҈

é r r r r q ù E =  ê k ᨨ犨 矄 � E҈ + E + E = d  ú  ëê r 㡰 ûú

ᆠ�ᆠᨨ � 盐ᨨ ᆠ �矄M

é +q -q q q q q ù + - + = ë r r r r r r úû

V =kê

ᆠ盐  盐ᨨ �

鼀ᨨ矄ᨨ矄��  ��ᆠ �矄�矄 ᨨ 和�鼀�泐   ᆠ盐  盐 ᨨ ᨨ  ᆠ �矄 �  �矄 �矄 ᨨ  ᨨB㦨\m㦨 㡰



 ᆠ�矄 泐҈맔҈黨  

ᨨᆠ�ᆠ 盐  ᨨ盐� ᆠ�泐 =





ᆠ 㡰 ᨨ �ᨨ ᨨ� 矄�ᨨ  ᆠᨨ 盐ᆠᨨ�矄矄鼀

盐矄ᨨ �A㦨ᨨ �B

q  �矄ᆠᆠᨨ � �ᨨ෌盐矄矄Ἐ矄 Î

 ᨨ鼀 졠�ᨨ  㡰   㡰     ᨨ    ᆠ盐盐 犨 �ᆠ  �矄 �  ᨨ� 矄A  Bᆠ盐矄ᆠ�泐�矄��ᆠ 㡰 턼�矄 �ᆠ盐ᨨ  ᨨ    �ᨨ 









㝐 졔





ᔴ泐ᆠ�ᆠ �   ᆠ  Mᨨ    �ᨨ  盐ᨨ   ᆠ �矄 ᆠᨨ 矄ᨨ �盐  �ᨨ �矄 ᨨ

쟼

쟼 쟼졔 ҈ ҈ 쟼졔 ҈ 쟼졔   E+  =  E-   쟼

� E㦨M 泐矄泐鼀鼀泐㡰



 㝐 







 ᆠ�ᆠ �  盐ᨨ ��ᆠ �矄쟼�

㦨和�鼀�泐   ᆠ�ᆠ �  盐ᨨᨨ矄��ᆠ �矄쟼ᨨ盐㦨 \쟼㦨

ᆠ�ᆠᨨ � 盐ᨨ ��ᆠ �矄M�矄 �   ᨨ鼀  ᆠ�ᆠᨨ � 盐ᨨ ᨨ矄��ᆠ �矄 M \¹㝐 ␔     矄泐矄鼀 ᨨ  ᆠ �矄 ᨨ 犨 �  ᆠ盐  I҈ 盐 ᨨ

��ᆠ �矄   ᨨ  ᆠ盐  I 盐 ᨨ ᨨ矄�� ᆠ �矄

 鼀� �盐  ᨨ  B  M 盐 ᨨ   ᆠ盐 矄 �矄 �   \B¹ m ¹ ᆠ�ᆠ �  盐ᨨ �  ᆠ �矄ᆠ ᆠᨨ盐� �矄 \쟼㦨 矄㡰

a







a

M

P 





Q

ᆠ�ᆠ � M 盐ᨨ ᆠ �矄�矄 ᨨᆠ盐矄

ᨨ �M 盐ᨨ ᆠ �矄

WWW.JEEBOOKS.IN

PS-199

Electrostatic Potential and Capacitance

é +q q æ q öù V = kê + - ¹ ç �a ÷ ú a⏌ a⏌ ê ú ç ÷ è  ø úû ëê



㡰

 졔



㝐

҈  ���㡰 

᲼Q 턼µ 桌

ᨨ鼀⼄ �㡰 ��㡰   ���㡰

␔     犨 ᨨ 矄泐矄鼀 �矄 矄 � ᨨ ᨨ�ᨨ  犨�   ᆠᨨ 矄   �盐ᨨᆠ�泐ᨨ盐  � PQ犨 � ᨨᨨ矄� 犨 �ᆠ ᆠ盐 �矄 ᨨ犨� �

 鼀� �ᆠ �  盐 ᨨ  矄 ᆠ盐 矄 ᨨ 盐ᆠ  矄盐  鼀� �ᆠ �  M犨 �ᆠ  �矄 ᨨ⼄盐ᨨ ᨨ  ᨨ  鼀� �ᆠ �ᨨ鼀ᨨ鼀 犨�ᨨ 盐ᆠ  \B¹ m¹



 µ

\

ᔼ µ  

 㦨ᔼ µ  ҈ 

P 泐ᨨ�  �矄 ᆠx ᨨ鼀 ᨨ��� 꾀矄矄 ᨨ犨 �

  ��盐    犨ᨨ ᨨᆠ矄 ᨨ  盐矄�ᨨ  ᆠ� � 盐 ᨨ 犨ᨨ ᆠ �矄ᨨ 졔鼀ᔴ   ᨨᆠ�矄Fᆠᨨ矄aᨨ犨 矄��  和�鼀�泐 犨ᨨ ᨨᆠ矄ᨨ ᆠ�ᨨ  盐ᨨ犨ᨨᆠ �矄ᨨ ҈鼀ᔴ   ᨨᆠ 盐ᨨ 矄 ᨨᆠ�矄FἘᆠᨨ矄bᨨ犨 矄 







쟼¹矄 犨� ᆠ�ᆠ �  盐ᨨ  �鼀  ᨨ ᆠ �矄Mᨨ犨 矄 �� 矄�  쟼ᆠ�ᆠᨨ �V㦨M 盐ᨨ矄泐鼀鼀�ᆠ �鼀 ᨨ ᨨ矄��  ��ᆠ �矄 ᆠ盐  �矄 ᨨ 犨     矄泐矄鼀ᨨ  ᆠ �矄 ᨨ矄 ᨨ盐 PQ 盐ᨨ矄泐鼀鼀�ᆠ �鼀 ᨨ ᆠ �矄\B㦨 m㦨  㡰 ᔼ ᨨᆠ矄矄҈犨ᨨ├ ᨨ 泐泐犨㦨⼄맔㦨ᔴᨨ맔ᨨ㦨 ᔴᨨ

҈  쟼 �泐矄ᨨ �  泐쟼ᔴ㦨 ᔴ 

K ´  ´ ҈ - ´ ҈ ´ ҈-

 �矄矄�  ᆠᨨ矄矄 矄�矄 ᆠ 쟼㦨␔쟼ᔴ㦨ᔴ �

   V ö ù V ö ҈ éæ Vᨨ ö æ V æ - ÷ + ç ᨨ - ᨨ ÷ + çVᨨ - ᨨ ÷ ú C êç ø è  è  ëè  ø  ø û



䰘

҈ CVᨨ  

㡰 꾀�ᆠ盐 ᔼ µ 턼µ 

턼 

x +

´



䰘 

x

 x + 

 Þ x㦨᠀

� 

� m ᨨᆠ�矄盐矄�ᨨ犨 矄졔vex㜠 �矄  ᨨx 

 ´ 黨 ´ ҈黨 ´  ´ ҈ - � 䰘 +  

é ë

-

҈ù

 ´ 黨 ´ ҈黨 ´ ҈ - �  +   

㦨맔黨맔҈黨맔҈ ê - ú = 䰘 ´ ҈   

û

⧤� �ᆠ  �泐�矄 ⼄盐�  ᨨ ᨨᆠᨨ鼀   ᨨᆠ ᨨ  盐矄�ᨨ

 �㡰  ��㡰

҈    F qE ö ҈ 턼쟼  ҈ æ 턼 ´  ö  æ  㦨 ç 㦨 ÷ ÷ ´  çèQ a = = m mø  鼀  è 鼀 ø ᨨ鼀和㦨盐졔

æ  ö ç x + ÷ è ø

x

´

� m ᨨᆠ�矄 ᆠ�ᨨ犨 矄 �� x㜠 �矄  � 쟼ᆠ�ᆠᨨ �ᨨ   ᨨ盐ᆠ �矄x㦨  V㦨

ᆠ㡰 꾀  ᆠᨨ� � �   ᨨ     犨� ��  �� ᆠ � � 泐 ᨨ ᨨ盐 ᆠᆠ├ᨨ  ᨨᨨ鼀  盐 ᨨ ᨨ  ᆠ盐 矄�鼀 鼀ᨨ �ᆠ 鼀ᨨ�ᨨ

矄 ᨨᆠᨨ �µx



K ´ ҈ ´ ҈- ´ ҈ ´ ҈-

꾀x>

\ ᨨ  �泐 �矄矄�  ᆠᨨ矄矄   矄�矄 ᆠ

ᨨEd㦨

㦨

҈ ᔴ   � 㡰  

҈  㦨 ᔴ   � 㡰 

ED =

æ  䰘 ö ç x +  ÷ è ø

҈ ҈ ᔴ  = ᔴ   

\쟼ᔴ㦨쟼 ᆠ㡰 �   � ��  � ᨨ�� ᆠ 矄ᨨ ᨨᆠ矄矄  

쟼 �泐 �矄矄� 㦨␔泐  D 㦨 ᔴ   � 㡰 

ᨨ  ᨨᆠ ᨨᆠᨨ鼀 ᨨ Fᆠᨨ矄a㦨F'ᆠᨨ矄b

ᨨ鼀µᨨx㦨

�  

犨ᨨ├ ᨨ �  �矄ᨨᆠ矄矄W㦨q V㡰 \ W㦨҈맔҈맔䰘맔҈㦨䰘맔҈ 泐 �泐ᆠᨨ 矄�ᨨ 

҈ mV 㦨䰘 맔҈ 

WWW.JEEBOOKS.IN

EBD_8341 PS-200

Þ

Physics

҈ ´  ´ ҈- V = 䰘 ´ ҈- Þ V㦨鼀⏌矄 

K.E. at the ᨨr�g�n ᨨ �  ᨨ���

Vx 㦨㦨

҈

 ´ 黨 ´ ҈黨 ´  ´ ҈ - 䰘 

-

 ´ 黨 ´ ҈黨 ´ ҈-

㦨맔҈ 꾀��  泐 �泐 ᆠᨨ 矄�ᨨ

 

ë

r

黨

졠   �  ᆠᨨ ᆠ

é R

sa e 

ᔼ  ෌ 

Sn = ᨨ

a 

qs a  + x - x㡰 e 



\ U 鼀� =  鼀� ᨨ鼀 ⼄盐�ᨨ  ��㡰 �  犨

U x㡰 xᨨ�矄矄矄 ᨨ犨

ᨨ犨

҈

QR é æ R ö ê҈  ç ÷ r êë è R + r ø



ú úû

qn qn = C  (  pe R )



 ��㡰

U( A) = mgH + mg é a  + H  - H ù ëê ûú

H㦨

) 犨 r �矄ᆠᨨ鼀鼀ᨨ �ᨨ

é QR ìï æ R ö n üï ù ҈ ҈ ᨨ U n = ´ ´ê í҈  ç ÷ ýú  pe  R ê r ï è R + r ø ï ú î þû ë 㡰 �鼀�� �盐ᨨ  �泐矄 n ® ¥ 盐矄ᆠᆠ盐qn犨  n 矄ᨨ ¥ a ᨨ෌ S ¥ = 犨  r҈ = ᆠᨨ鼀鼀ᨨ  �ᨨ ҈ - r҈ QR é QR ҈ ù ᨨ q¥ = \ q¥ = R ú R+r ê r ê҈ ú ë R+r û   q¥ ҈ æ QR ö \ U¥ = =ç ´ ÷ C è r ø  ´ ( pe  ) ´ ( R )

b㡰 ᨨᨨ � �泐ᨨ   �ᆠ ��  H U x㡰㦨mgx졔qV x㡰



(҈  r҈ )

qn =

Un =

mgH㦨mg ᲼a - { a + H 㡰 - H 晤桌

= mg é  a  + H  - H  ù êë úû dU ᨨ⼄盐���盐鼀 = dH a

(

a ҈  r҈n

쟼ᆠᨨ矄�ᆠ �泐ᨨ S  n 矄盐ᆠ  ᆠᨨ ᆠ矄



㦨mgx졔mg ᲼ a  + x 㡰 - x桌

û

n  é R æ R ö æ R ö ù +ç + +  qn = Q ê ÷ ç ÷ ú R+r è R+r ø è R + r ø ûú ëê

盐� � �矄盐� ⼄盐�ᨨ  �㡰

㦨mgx졔

 æ R ö ù

ë

s mgH㦨q ᲼a { a  + H  㡰 - H 晤桌  �㡰 e   e  g = Þ  sq = mg ᨨ鼀 �� �ᨨ  m s e 

H㦨



졠    ᆠᨨᆠ

␔     �ᆠ �矄 ᨨ  ᨨ �    �矄 ᨨ  �矄  �泐 �矄 ᆠᨨ 矄 ᨨ矄矄ᨨ ���ᨨ ᨨ � �泐㦨�� � ᆠ�ᆠ ᨨ �  �泐 mgH㦨qDV㦨q᲼V 㡰V H㡰桌

ᨨ

æ R ö

q㦨Q ê R + r + çè R + r ÷ø + çè R + r ÷ø ú ê ú

s ᲼ a + H  - H 桌 e 



=

æ R ö ᨨ rq = RQ  Rq + RQ ç è R + r ÷ø éæ R ö æ R ö  ù ᨨq㦨 Q ê ç ÷ +ç ÷ ú êë è R + r ø è R + r ø úû

꾀x㦨H

꾀 V O㡰㦨

kq҈ ҈ æ R ö 犨  k = ᨨ q҈ = Q ç ÷ R pe è R+r ø

kq r R ᨨ rq = RQ  Rq + Rq҈

s ᲼ a  + x - x桌  e

V H㡰㦨

=

k éëQ  ( q  q҈ ) ùû

⧤쟼㦨҈맔҈᲼䰘맔҈맔҈桌 㦨҈맔҈맔맔҈㦨맔҈ 㡰 ෌�  a 㦨  �盐矄 ᨨ  �矄ᆠ s 㦨 矄盐 ᆠ ᆠ �  矄�泐 q⏌m㦨eg⏌s ᨨ � 盐 ᨨ  ᆠ �  �矄ᆠ   泐 � ᨨ�  矄�盐    �矄 ᆠx ᨨ鼀O V x㡰㦨

�矄 矄 ⼄盐���盐鼀 ᨨ矄��ᨨ 

졠  矄ᆠᨨ ᆠᨨ ᆠ 矄�鼀�泐

û





㡰 S҈ᆠᨨ � ᆠ �Q ᨨᆠᨨ ᆠ犨� S 졠 ᆠᨨ ᆠᆠ �q҈矄 �  ᨨ鼀S҈ᨨS

k (Q  q҈ )

V - Vx =  ù ⧤쟼㦨q é x= � ê ú \

a

 ᆠ H =

 ���㡰

ᨨ ҈҈

U¥ =

Q R 

r  ´  ´ pe R

ᨨ U ¥ =

Q R  ( pe ) r 

㡰 꾀ᆠ � �矄 盐 � ᨨ鼀泐 �矄�盐  ᨨ  ᨨ 㜠ᆠᨨ 盐ᆠ� � 矄 �ᆠᨨ盐鼀ᨨ  �盐矄R盐矄ᆠᨨ 矄� 矄 ᨨ   �ᆠ├ 矄矄 dx �矄 ᆠx ᨨ鼀 ᆠ ᨨ 矄  ᨨ盐鼀ᨨ  矄 㦨

 é  ù p ê x + dx 㡰 - p x  ú  ë  û

WWW.JEEBOOKS.IN

PS-201

Electrostatic Potential and Capacitance

ᆠ㡰 ᔼ    矄鼀ᆠ � ᨨ  Q ᆠᨨ ᨨ鼀 �矄 ��  ᨨ  矄 �ᆠ ᆠᨨ 盐ᆠᨨ ᨨ    矄鼀  �盐矄    C = pe  R    �泐

   㦨 p éë x + dx㡰 - x ùû   ù   é æ dx ö p ê ҈ + x 㦨 çè ÷ø - ҈ú x  ëê ûú 㦨

E= ҈

  é dx ù p x ê҈ + - ҈ú  x ë û

=

҈

r ᆠ �盐 �ᨨ盐鼀ᨨ  矄  \ ᔴ �ᨨ  矄 㦨dq㦨pxrdx  �㡰 ᨨ � 矄盐 ᆠᨨ  矄 ᨨ  �盐矄x

҈ 㦨 ´ pe 

 r ´ px   x

㝐� �鼀盐鼀 �鼀 ᨨ   �ᨨ ᨨ ��  ᨨ �   �ᆠ�ᨨ  ᨨ ᆠ�ᆠ � t㦨

  dx px ´ 㦨pxdx x 

҈ Q ҈ Q =  pe  R  C

T p ML p ML  = =   qE  qE

쟼ᆠ �ᆠ犨�� ⼄盐���盐鼀盐  ᆠᨨ   ᨨᆠ  矄�ᨨ  ᨨ 矄� � T 犨�� � � 矄盐  ᆠᨨ矄�ᆠ ᨨᆠ F ᨨ  犨ᨨᨨ ᆠ �矄 ᨨᆠF 鼀� �ᆠ盐

qù é êëQ V = k r úû

\ ᨨ �    矄盐 ᆠ ᨨ    矄  ᨨ   �盐矄

x㦨

rx  e 

␔ᨨ├ ᨨ � � �� � ᆠ �dqᨨ  矄 ᨨ  �盐矄 xdW

rx  rx  㦨 맔dq Þ dW㦨 맔p xrdx e  e 

\ ␔ᨨ├ ᨨ  �  ᆠᆠ盐鼀盐� �   ᆠ � Q ᨨ  矄 �ᆠ ᨨ盐鼀ᨨ  �盐矄R R pr

pr x dx = W㦨 ò  e e   

R

é x� ù pr R� ê ú = e  � ëê � ûú 



 p æ Q ö R� Q  = 㦨 ç ÷ e  è  ⏌ pR ø �  pe R

矄ᨨ� � T �    �ᆠ�ᨨ  ᨨ  mg   F   泐� �   ᆠᨨ ��ᨨ  ᨨ  ⼄盐���盐鼀

F \  q 㦨 mg

Q  KQ  ҈ = 犨 K㦨 � ´ pe  㡰 R �R pe  ҈ ᆠ� � ᨨ⧤泐G Q泐 M  pe

\ g㦨

E㦨

GM �R

\

gR

 Þ G㦨 M R 



E =



F㦨 FCA =



´

҈ 

kq 

 ��㡰

CA㡰  ur ur  F CB  =  F CA   a㦨 桌

T鼀├  � q 犨�  �ᆠ OC㦨 \

 㡰 - ҈�㡰 㦨҈䰘鼀 

OM㦨黨黨黨䰘

\ q 㦨

 gR M   ҈ 㦨 gMR = ´ ҈ ´ � ´ ҈ � M R � � = ҈� ´҈ 

\



F㦨 FCA + FCA +  FCA ´



GM

 �㡰

  F㦨 FCA + FCB +  FCA FCB ᆠᨨ矄 a

�矄犨ᨨ├ ᨨ �矄 ⼄盐ᨨ   �泐矄ᨨ �   矄泐矄鼀 b㡰 ᆠᨨ矄ᨨ � � �泐   ᨨᆠᨨ鼀泐 �矄矄矄鼀       �� 矄   ���ᨨ 盐 E㦨

T矄� q 㦨F

Tᆠᨨ矄 q 㦨mg錐

OC ҈䰘 = OM 黨黨黨䰘

 ���㡰

ᨨ鼀⼄ �㡰 ��㡰  ���㡰

҈䰘  ´ 黨 ´ ҈黨 ´ ⼄  = 黨黨黨䰘 㡰  ´ ҈- ´ 黨 \q㦨҈맔҈黨ᔴ

WWW.JEEBOOKS.IN

EBD_8341 PS-202

Physics

Current Electricity

17

Topic-1 : Electric Current, Drift of Electrons, Ohm's Law, Resistance and Resistivity ҈



҈�

黨 ´ ҈ ´҈ ´ ҈-҈黨 ´ � ´ ҈ - ҈

ᆠ㡰 꾀鼀鼀  ᔼ  矄�矄 ᆠᨨ

ᆠ�ᨨ   矄鼀ᆠ盐  ᨨ犨矄  ᨨ盐�    ᆠᨨ鼀ᨨ  矄 ᔼ �鼀矄 鼀矄盐� �   ᆠ盐  ᨨ犨� � ᨨ盐�  ᆠ�ᆠ盐�   ᆠ��矄ᆠᨨ

ᆠ � 矄�矄 ᨨ鼀꾀ᨨ鼀鼀矄盐矄ᨨ�ᆠ  �犨 犨ᨨ ᨨ� 矄� ᆠ�ᆠ盐�和ᨨ犨 ᨨᆠ ᨨ鼀�  犨�   ᆠ�ᆠ盐� ᆠᨨ鼀ᨨ   b㡰 rM = 黨 ´ ҈-

r A = � ´ ҈- rC = ҈䰘 ´ ҈- rT = �� ´ ҈- \rM > rT > r A > rC

 

㡰 㡰

 쟼

҈҈

Þ m=

쟼 쟼꾀 ᔼ r㡰 = Þ 쟼=  ᔼ 꾀

  꾀 = = 쟼 ᔼr

(

҈҈ ´҈  ´ p ´ � ´҈ 

)



҈

dR =

� ´ ҈䰘 ´҈ 

px

䰘



dx  px

b

 Þ

R=

r é -҈ ù p êë x úû a

æ r ö æ҈ ҈ö R = ç ÷ ç - ÷ è p ø è a b ø m ᆠ㡰 r =  ne t 黨҈ ´ ҈-҈ = � ´҈ ´ ҈ ´҈-҈黨 㡰 ´ � ´ ҈ -҈� 㦨҈W㜠鼀 㡰 盐鼀�矄矄矄ᨨᆠ� 犨�   ᆠᨨᨨ盐 �矄ᆠᨨᨨ盐�矄 ᆠ  泐 �  Q ᔴᨨᨨ盐ᆠᨨ  ��盐 ᨨ� �矄� \犨矄�矄 ᆠ㦨�W 㡰 ᔴ泐 ᨨ鼀 � ᔴ盐 ᔼ㦨

黨

㡰

෌�  ҈㦨҈WἘ㦨⏌ 㦨䁸

ᨨ a =  ´ ҈

r

-

°ᔴ - ҈

rl Q꾀맔 � 㦨ᨨ盐鼀 꾀

꾀

⼄ =   = 矄 ᲼和� ᆠ⼄�矄ᆠᨨ 矄 桌 

矄� �ᔼ㦨 꾀

\�  矄  =

҈

꾀

µ

҈

ᆠ㡰

쟼ᆠ�ᆠ �  �矄 ᆠr ᨨ鼀� ᆠ �



ᨨ µ

҈

Q꾀㦨p

꾀   = ҈ Þ  = ҈ ´ ҈ = ҈ W 矄�矄 ᆠᨨ  犨犨� ҈





b



㡰

 ᆠ =

r㡰 dx㡰

ò

a

҈ ҈ ´ �

和� ᆠr ®ᆠᨨ 矄  ®ᆠᨨ 矄 

 R = dR

ò dR = rò

a=

矄�矄��泐ᨨ 犨� =

鼀 m = ҈ 矄 㡰

  = = ҈҈W ᔼ 

㦨҈ �� 㡰鼀盐ᆠᨨ �ᆠ� ᨨ 矄�矄 ᆠa㦨䁸 盐矄� � 㦨  ҈졔a㡰 ҈҈㦨҈ ҈졔a�㡰



�

矄�矄 ᆠ   鼀盐 � ᆠ矄矄 泐� ᔴ �

ᆠ㡰

 =

[ ␔  = � ᨨᆠ�泐 ]

  矄�矄��泐 ( r ) =

㡰 ᔴᨨᨨ盐ᆠᨨ  ᨨᆠᨨ  矄�矄ᨨ  졠Ӹ෌盐෌␔ ҈�䰘黨 矄�矄 ᆠ 㦨꾀맔ᔴ᠀  矄꾀   �矄犨ᨨ矄�� � �ᆠ  ��盐矄ᨨ 矄�矄 ᆠ  ᔴ� �ᆠ矄  ᆠ�鼀鼀盐��ᨨ  盐鼀ᨨ  ᨨ矄   ᨨᨨ犨꾀   �矄ᨨ ᆠ෌ᨨ 㦨᠀�奠 和�㦨᠀҈奠ᨨᆠᨨᨨ盐㦨᠀奠

= � ´ ҈ ± �奠 = �├W ± �奠

␔  �㦨V㦨e㦨҈�ᨨ ᔴ � 鼀ᨨ��泐

m㡰 =

㦨鼀鼀矄҈

҈

dV l =  per dr l dV =  dr per E=

l㦨� ᆠ �  矄�泐ᨨ 犨�㡰

ᔴ盐  ᨨ盐�  鼀 矄 

l dr lsl  dV  per I= = = dr ҈ dr e ´ s prl Q = r

l  ҈ dr 㡰 \ = r = 꾀 prl s prl

�矄 ᆠ盐  �矄  �泐 ᨨ盐犨 矄

d  lsl \ ( ll ) = Þ dt e  ( s ⏌ e )t

l

ò

l

t

dl æ sö =  ç ÷ dt è eø l

ò 

Þ l = l e lsl ls I \ J= = = prl perl per

WWW.JEEBOOKS.IN

PS-203

Current Electricity

æ l  s ö  ( s ⏌ e )t e Þ J = J  e ( s ⏌ e ) t per ÷ø l b㡰 V = IR = neAvd 㡰r A  \ r㦨   

҈

ᨨ J = ç è

҈

和ᨨᨨ �  㦨





 ´ ҈



´ ҈ ´ ҈

-҈黨



´ � ´ ҈- ´ ҈

ᆠ㡰

� 㦨 neAVd   Vd µ

E  ෌� 㡰

ᨨ � µ E � µ E � µ V  ᆠ�  ᆠ㡰ᆠᨨᆠ泐 ��ᆠ矄 V㜠I�  ᨨ犨�鼀  ᨨ  矄盐ᆠ  泐 ᨨ  鼀� ҈

\ R=

҈䰘

L

 ᆠ R�矄�   ᨨ  L  � 矄泐ᨨᨨ�ᨨ ᨨ t ᆠ㡰 꾀ᨨ鼀�矄鼀 泐ᆠᨨ

ᆠ� � �� 矄�矄 ᆠR҈ �

矄�矄犨�  � ᨨ鼀G҈



꾀 鼀鼀�矄鼀 泐ᆠᨨ

ᆠ� �ᨨ犨矄�矄 ᆠR�  犨�  � ᨨ鼀G



ò



G

҈

pr æ ö l ç  ÷ è ҈ ø

҈黨







I V

҈  s

ᔼ ᆠᨨ 盐ᆠ� �矄ᨨ�  ᆠᨨ�矄�ᨨ 矄ᆠᨨ鼀鼀ᨨ ⼄盐 犨� � ᆠ矄ᨨ  鼀盐

R

҈

æ ö   l ç  ÷  è ҈ ø Þ ᔼ=  = pr

 ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ ᆠ㡰  ᆠᨨ 盐ᆠ��泐 s㡰 ᨨ   矄鼀�ᆠᨨ 盐ᆠᨨ � ᆠ矄矄 犨� � ᆠ矄 �  鼀盐 �   矄�矄��泐 f㡰 ᆠ矄矄 犨� � ᆠ矄� 鼀盐矄P㦨

ᨨ鼀 �矄ᆠᨨ

ᆠ  �  犨�    矄 矄�矄ᨨ RT  �

ᆠ�ᆠ盐� 꾀鼀鼀�矄ᆠᨨ

ᆠ � 矄�矄犨�  矄矄�矄ᨨRT�  ᆠ�ᆠ盐� 꾀� ᨨ�矄ᨨ盐ᆠ V�矄ᆠᨨ

ᆠ �  矄�矄犨�  矄 矄�矄ᨨRT �  ᆠ�ᆠ盐� 㡰 ᔼ  ᆠ�ᆠ ᆠ�ᆠ盐� 鼀鼀 �矄 ᆠᨨ

ᆠ  �  矄�矄 犨� 矄�矄 ᆠ   ᨨ鼀  犨�     矄�矄 ᆠ ᔼ ᨨ 鼀Ἐ矄犨犨ᆠ ᆠ├V㦨IR 泐泐� � 矄�矄 ᆠᨨ   ᆠ�ᆠ盐� 㡰 ᔴᨨ �矄 鼀犨 矄 ෌鼀 �盐鼀�矄 和鼀�㜠ᆠᨨ 盐ᆠᨨ 矄�矄 ᆠᨨ 鼀 ᆠ矄矄 矄鼀�㜠ᆠᨨ 盐ᆠᨨ� ᆠ矄矄犨� ᆠ矄�  鼀盐 㡰 矄�矄 ᆠ � ᆠ矄矄 犨�  鼀盐 矄 졔  ҈졔µ㡰 R҈㦨R ҈졔a t҈㡰Þ҈㦨 ᲼҈졔҈�맔䰘桌 R㦨R ҈졔a t㡰Þ㦨R᲼҈졔҈�맔 t桌 和ᨨ� �犨� T㦨� ᔴ㦨� ᔴ졔䰘 ᔴ㦨҈҈䰘⧤

T2

 ҈  æ  ö Þ = l ç ÷ pr è ҈ ø rp

r r 鼀  鼀  = ⼄쟼 Þ 쟼 =  ⼄ R҈ r 鼀ᔼ 쟼= 

 꾀 ⼄ I ᔼ ö æ Q �  ᨨᆠ�泐  = çè ÷

꾀 ø r uur D = ò 쟼  ᨨ D µ    \D µ ᔼ

t



҈ 矄ᨨᨨ �

 ᆠᨨ�ᨨ  㡰�矄ᆠᨨᆠ 꾀  ᨨᆠ�ᆠ盐鼀ᨨ�ᨨ ᨨ ᆠᨨ D ᨨ矄 ᔼ

 矄盐 ᆠ  ��  ᨨ � 矄ᨨ   ᆠ�ᆠ �  ᨨ矄  �泐 ᨨ盐犨  R 和ᨨ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ DV

L

rL r = L´t t

҈ =

矄�矄 ᆠ  =

l ᆠ㡰 ␔├ ᨨ犨矄�矄 ᆠ R = r a  l㦨L a㦨L맔t

T1 I

和ᨨ㡰T 和ᨨ㡰T҈\ 矄�矄 ᆠ㡰T> 矄�矄 ᆠ㡰T ҈ V ᨨ  鼀�ᆠ 犨� 矄�矄 ᆠ � ᆠ矄矄 犨�  鼀盐 \T>T҈ 矄盐ᨨ 鼀 �泐ᆠᨨ 矄� ᆠᨨ 盐ᆠᨨ    鼀ᨨᆠ��矄 ᆠᨨ 矄 鼀ᨨ�ᨨ �  ᨨ鼀 �ᆠ�ᨨ 矄  �  矄 ᆠᨨ ᨨ � �  ᆠ ᆠ 㡰 矄�矄 ᆠ ᨨ  鼀 泐矄�矄



㦨҈맔҈� W鼀 ҈�

I ҈ = V R

Þ 矄�矄 ᆠ R =

 㦨ᨨ � �  ᆠ 㦨 � ᨨ 犨�

 㦨 ᨨᨨ ᆠᨨ 矄盐 �ᨨ盐鼀ᨨ ᆠᨨ 盐ᆠᨨ 㦨 ᨨᨨ ᆠᨨ 矄 ᆠ� � 盐ᨨ ᨨ鼀矄 犨�矄�矄��泐

r=

T盐 ᨨ鼀 �� ᨨ�ᆠ盐 �

�

l A V 꾀  V = Al Þ A = (V = ᨨ盐鼀 ᨨ 犨� ) l rl rl  \R = = V ⏌l V  r Vᆠᨨ 矄  \R µ l DR ´ ҈ =  \ ᆠ � ᆠ  � �  矄�矄 ᆠ R 奠ᆠ  �� l㡰㦨 ҈奠㡰㦨奠 꾀矄犨 ├ ᨨ犨矄�矄 ᆠ R = r

Topic-2 : Combination of Resistances ҈

b㡰

ᨨ鼀ᆠ�ᆠ盐� ��鼀

҈ ҈ ҈  = + Þ R҈ = R҈ ҈  � ҈ ҈ ҈  = + Þ R = R   �

WWW.JEEBOOKS.IN

EBD_8341 PS-204

Physics









䰘

R = R҈ + R =

�=  

ᆠ㡰 ᆠ㡰

  + = W � �



 ´ ҈ � = W ҈ 







⼄ 㦨 











㡰 ᔼ  矄 泐矄 ᨨ犨 ᨨ ᆠ盐   ᨨ盐�  ᆠᆠ�ᨨ 犨�  ᨨ ᔴ盐  ᨨ盐�    ᆠ�ᆠ盐�

E r + r

Vc = 

R㦨맔㦨҈W R⼄㦨







ᨨ � �  ᆠ  ᨨ盐�  ᆠᆠ�ᨨ

␔    �  ᆠᨨ鼀矄 ᨨ盐 �矄 矄�矄 ᆠ ᆠᨨ鼀矄

R Ҙ l  㡰



�=

� � � v  = = ҈ A \ I BC = - = =  A � � � R 







黨

æ E Q = E - �r 㦨 E - ç C è r + r

ö r ÷ r \ Q = CE r + r ø

b㡰  ᨨ � �  ᆠ�  ᆠ ᨨᨨ�矄 ᨨ \ᨨᆠ盐 犨� ᨨ犨ᨨᆠ盐 � ᆠ 矄�矄 ᆠ�矄ᨨ b㡰

꾀矄矄�矄 ᆠᨨ 犨�R㦨

òA l

rFe ´ lFe ҈䰘 ´ � ´҈  � = = ´҈ RFe㦨   AFe  ´ ҈

ᆠ㡰 RR R�� 矄�矄矄ᨨ �⼄盐�  R㦨졔�졔�㦨�W

�矄 �矄 犨�  R  矄ᨨ 矄�矄 ᆠᨨ   ᆠ�ᆠ盐�

r Al ´ l Al 䰘 ´ ҈  ´ � ´ ҈  䰘 ´ � = = 맔҈� RAl㦨 AAl 黨  㡰 ´ ҈  �

㦨맔҈ 꾀矄ᨨ � �  ᆠᆠᨨ矄矄ᨨ  矄�矄ᨨ矄�矄 矄鼀矄ᨨ 泐 �   ᆠᨨ鼀� �ᨨ 

\ RPQ㦨 ҈

矄�矄 ᆠ犨   턼

� ´  æ  ö  = � 턼㦨  P ç + ÷ = è  ø � ҈҈ +  

҈ æ ҈ ´ � ö W ÷ + ҈� +  =  è ҈ + � ø e ҈� 黨 = = A 和ᨨ � = R⼄ (҈ ⏌ ) 

R⼄ = ç

�

b㡰

RFe ´ RAl ҈� ´҈ ´  ´ ҈ ҈䰘� = = mW  RFe + RAl ҈ ´҈

矄�矄 ᆠ犨 턼 

  ´     턼 = P  + 㡰 =   =      +  ҈҈  

㡰

矄�矄 ᆠ犨  

矄�矄 ᆠ  µ l 矄ᨨ 矄�矄 ᆠ ᨨ  ᆠ  矄�  ᨨ    ⼄盐� � �㦨W 矄�矄 ᆠ ⼄ 犨   泐犨ᨨ �ᆠ矄

҈ ҈ ҈ 㦨 졔 Þ ⼄ =  W ⼄ ҈  

㡰

矄�矄㦨 ҈졔 졔졔

҈ ҈ ҈ ҈ = + +  +  ҈ 

  ´   æ ö    =   = P ç + ÷ =  è  ø  +   ҈҈   ҈҈

 ᆠ��矄ᆠ 턼�矄鼀 �鼀盐鼀 㡰 ᆠ盐 � W矄�矄ᨨ㦨 ᨨᆠ盐矄��矄 ᨨᨨ  泐ᆠᨨ矄  ᨨᨨ ҈

�W

 ҈W

W

WWW.JEEBOOKS.IN

PS-205

Current Electricity ෌�  矄�矄 ᆠᨨ ᆠ  矄�矄ᨨἘ Ἐ

ᆠ㡰

RPQ ҈

҈

㡰

�   R RQR = R  RPR = R = ҈҈ ҈҈ ҈҈

\ 턼�矄鼀 �鼀盐鼀 㡰  ᆠ�ᆠ盐� ᨨ   ᨨ犨   �矄 POQ 矄泐鼀鼀�ᆠ   矄 矄  ᆠ  犨 矄ᨨ  � �  ᆠ   ᆠ  矄�矄 ᆠ �矄�  ᆠ� R

R

R

R

r

r

R

R

R r

 矄�矄 ᆠ ᨨ  W �矄 �   犨�  R �  ᆠ� 矄�矄 ᆠ

r

P

Q R

R

P

2R

Q

҈ ҈ ҈ = + R Ἐ  R  R RἘ =  + R

 ᨨ  ⼄盐� ᆠ�ᆠ盐��矄 犨  矄 ᨨᨨ犨矄

r + r + R ҈ ҈ ҈ + + 㦨  Rr RPQ  R  R r  Rr ᨨ RPQ㦨 R+r

҈

\

҈

ᆠ㡰

=

꾀矄ᨨ  㦨 ᔼ

R Ἐ = ҈� =

V  㦨 㦨҈꾀鼀 ᔴ盐 �  ᆠ�ᆠ盐�I = R  ҈㡰

҈䰘

ᔼ   ��盐 㡰 ᨨᆠ盐  ᨨ犨矄 ᨨ盐� W矄�矄 ᆠ

W

W

W

W

W

�

҈W ҈W

 ᆠ 犨 矄ᨨ  � � ҈ ҈ ҈ = + ⼄  

W

\ ⼄ =

´  = W + 

I㦨

҈

æ Rö ç ÷ 꾀  矄�矄 ᆠ矄 R R   R�  矄 èø

矄 ᨨ犨 �  ��盐

R ҈ ҈ ҈ ҈  = + + = ᨨRAB㦨  R AB  R  R R R R

 ᆠ

R

A

 ´ ҈ 黨 = W \R⼄㦨  

B

R

W W

W

 ᆠ 犨 矄ᨨ  � �

҈黨

 㡰 I

2k W

҈W

R

W

㡰

 ᨨ ᆠ盐  ᨨ盐�  矄�矄ᨨR㦨W

V � � = = = ҈A 黨 � R + 



V

҈W

k W

I=

矄� � �㡰

  = � 꾀 ҈ W

꾀��   ⼄盐� 矄�矄 ᆠᨨ   ᆠ 犨 矄ᨨ � � �� 㡰 ᨨᆠ盐  ᨨ盐� ҈W矄�矄 ᆠ

�

 R  + R

 ᆠᨨ鼀 � � V㦨EIR 㦨 �㡰 �꾀㡰 W㡰 㦨��㦨

㡰



 ´  R Ἐ+ �

Þ졔R㦨R Þ R㦨W 㡰�  ᆠ�ᆠ盐��矄ᆠ ᨨ �  ᨨ 鼀 ᨨ  ᆠ�ᆠ盐�㦨 �㡰㦨V ᔼ  矄�矄 ᆠᨨ ᆠ ᆠr㦨W 矄�矄 ᆠ�  ᆠ�ᆠ盐�㦨 W㡰㦨҈W \ ᔴ盐  ᨨ犨� � ᨨ盐�  ᆠ�ᆠ盐�

҈W W



Þ ҈ =

Þ R Ἐ+ � =  Þ R㦨҈�

ᔼ  �� ᆠ�ᆠ盐�

黨 ҈ ҈ ҈ = + = ÞR⼄㦨W R⼄    ´ 

҈�

 �㡰

Rp =

I RL 㦨҈�kW

҈



V Rp

R ´ RL  ´ ҈� 黨 = = kW R + RL  + ҈� 䰘�

\Rᨨ㦨R҈졔Rp㦨졔 () I =

黨 㦨kW 䰘�

V  = 鼀꾀 = 䰘� 鼀꾀 R 

WWW.JEEBOOKS.IN

EBD_8341 PS-206

Physics

I㦨IR

҈

\

æ RL ö æ ҈� ö IR  = ç ÷I = ç ÷ ´ 䰘� = ҈� mA è ҈� +  ø è RL + R ø

Þ R 졔졔R㦨R졔R Þ RR㦨 Þ RR졔R㦨 Þ R R㡰졔҈ R㡰㦨 Þ ᲼R졔҈桌᲼R桌㦨 Þ R㦨W

\IR 㦨IR IR 㦨䰘�҈�㦨鼀꾀 

㡰

҈



ᨨ � �  ᆠ ᆠᨨ矄矄 ᨨ ��㡰

VRL = ( IRL ) RL =  ´҈� = 黨V ᆠ㡰



\

҈







␔  R҈ R� ᆠ  �  

R҈P =

 kW 䰘

6W

6W

3W

6W

6W

3W 3W

3W

6W



W

W

6W

3W

W

W

D

3W

3W 2W

Topic-3 : Kirchhoff ’s Laws, Cells, Thermo e.m.f. & Electrolysis ҈

ᆠ㡰

�W

�

A

B

D

W

҈W W ᨨ¥

E �҈

҈

W W

� �

C

 W

W

F

矄� �⧤�ᆠ ᨨ Ἐ矄 ᨨᨨ犨 � ᨨᨨ ABCD

´R  R+

C ҈W

6W

҈W

  W W W ᨨ � �  ᆠ犨 A B VAVB㦨黨҈ 졔㡰㦨V㦨�҈ \�҈㦨�꾀 \�㦨҈�҈㦨�꾀 和�鼀�泐ᨨ � �  ᆠ犨  ᔴ  VCVD㦨 VAVB㡰� 졔㡰 㦨�㦨 �㡰㦨V㦨� \�㦨�꾀 \ �㦨��㦨��㦨�꾀 �㡰 ᔼ  ᆠ矄 ᨨ   � � �   ᨨ  矄�矄 ᆠ矄    ᆠ� 矄�矄 ᆠ 鼀� 矄 矄鼀 犨   ᨨ  �  �ᆠ�鼀 �矄    ᨨ 鼀ᨨ  ᨨ鼀� 쟼 ᆠ�矄�矄 ᆠ犨  ᨨ� 矄C D  R  

 ᆠ�ᆠ盐�ᆠ  犨 矄矄 ᨨ犨

쟼 ᆠ�矄�矄 ᆠ犨 A  B

A ҈W

3W

6W

3W

�҈ 졔 �

�

�҈

Req㦨҈졔

3W

6W

 ᆠ矄�矄 ᆠ犨 A BRAB㦨W

 ҈ =    ᨨ ᨨ犨 黨 



�

黨

3W

3W

 黨 = = ҈꾀 㦨ᆠ盐  ᨨ盐� W矄�矄ᨨ 黨 W

3W

Þ

6W

3W

3W

Þ

3W 3W

3W

V ᨨPµV犨� ᆠ矄泐 ᆠᨨᨨ 黨 R

҈꾀

B

6W

3W

6W

3W

6W

㡰  矄�矄 ᆠᨨ  ᆠ�ᆠ盐�㦨黨W \ᔴ盐  犨  ᨨ鼀 泐



Þ

3W



҈

6W

3W

� ᨨ犨 ᨨ � ᆠᨨ鼀矄

�㦨

3W 3W

3W

æ ⏌䰘 ö =  ç = V è  + 䰘 ÷ø

�矄矄� 㦨

 㦨꾀 

 = ҈�꾀 꾀 

3W 3W

3W

ᨨ犨  ᆠᨨ矄矄RL Ἐ VRL

�CD 㦨�EF 㦨

6W

R RL  ´ ҈�  = = kW R + RL � 䰘

RἘᨨ㦨졔R ἘP㦨졔

RAB㦨҈W졔҈W㦨W\IAB㦨

�CD 㦨�EF 矄矄�矄 ᆠ矄RCD 㦨REF

�ᨨᨨ ᨨ犨矄 �矄矄�  �  R҈   R

 PR҈ ( I R ) R҈ ( 䰘�) ´  � = = =    PR ҈� ´  ( ) I R (R ) 



´R 㦨 R+

҈졔

-�� - ҈ �҈ + � 㡰 - � +  =  Þ - ҈�҈ - ҈䰘� +  = 

 �㡰

矄� �⧤�ᆠ ᨨ Ἐ矄ᨨᨨ犨 �  ᨨᨨBEFC

Þ -҈ + �҈ + ҈ �҈ + � 㡰 =  Þ ҈�҈ + ҈� + ҈ = 

 ��㡰

㝐盐�泐� �⼄盐�ᨨ  �㡰泐҈ 犨 

҈�҈ + ҈䰘� = 㡰 ´ ҈ Þ ҈ �҈ - ҈䰘 �  = 

 ���㡰

㝐盐�泐� �⼄盐�ᨨ  ��㡰泐҈䰘犨 

҈�҈ + ҈� = ҈㡰 ´ ҈䰘 Þ �҈ - ҈䰘� = ҈䰘

 �㡰

졠 矄ᨨ� �⼄盐�ᨨ 矄 ���㡰  �㡰犨� A 

B

-҈�҈ =  Þ �҈ = -

1W C

R

2W D

F

 = -҈䰘 ҈

�҈ �矄 �� � 鼀 矄 ᆠ盐  ᨨ犨矄 ᨨ鼀 ᨨ矄�� ᨨ �� 鼀� 

WWW.JEEBOOKS.IN

PS-207

Current Electricity 





D

E ҈꾀

�

B



ᨨ犨 �  ᨨ 

W

҈꾀㦨�҈ �



�㦨꾀



A

æ e ö P㦨� R㦨 ç ÷ R è R+r ø dP = ᨨ鼀 �鼀盐鼀 dR

F



C 꾀 ҈ 盐矄矄矄盐鼀 ᨨ �A㦨VA㦨 矄� �⧤�ᆠ ᨨ Ἐ矄盐 ᆠ�ᨨ 盐C犨�

�҈ + � = � ҈꾀 + � = 꾀 Þ � =  A

ᨨ

ᨨ犨盐矄� �⧤�ᆠ ᨨ Ἐ矄ᨨᨨ犨ᨨ �ACDB

VA + ҈ + � 㡰 -  = VB Þ VA + ҈ + � ҈㡰 -  = VB  Þ VB - VA =  -  = ҈ ᨨ 

䰘

ᆠ㡰 ⼄盐� ᆠ�ᆠ盐�ᆠ  犨 矄 W

A

�

� ҈ W

C

꾀

쟼҈ 쟼  쟼  ҈   + + + + ҈   ҈ ҈ ҈  = ᔴ = = ҈ ҈ ҈ ҈ ҈ ҈ = =  + + + +  ҈   ҈ ҈ ҈

ᆠ㡰

ᔴ盐 矄矄� � ᨨ盐� 矄�矄 ᆠ ҈

W

W



 d éæ e ö ù êç ÷ Rú =  dR êè R + r ø ú ë û

ᨨ R㦨r b㡰 ෌� 쟼҈㦨҈쟼㦨쟼㦨҈㦨҈W 㦨҈W 㦨҈W

W W

æ e ö �=ç ÷ èR+rø



 ҈ = = �꾀  �㦨 ҈  ҈ ҈W  b㡰

҈ W  和 ҈ 턼   ҈W

�҈ =

 ᨨ�ᆠᨨ矄矄AC㦨 矄�矄 ᆠRAC㦨졔㦨W

�҈ = 

b㡰

黨

V  = = ҈ 꾀鼀 RAC  + 

ᨨ �� ᆠ�ᆠ盐�

矄� �⧤�ᆠ ᨨ 矄犨P犨�

 - ҈  - ҈  -  + + = ҈  ҈ ᲼ᨨ �턼㦨  㦨

�=

   ҈ ҈  Þ + + = + + ҈  ҈ ҈  ҈ ҈ + � + ҈  + ҈ æ ҈ ö 䰘 Þ = Þ ç ÷ = ҈  è ҈ ø  䰘 ´҈ 䰘 Þ= = = ҈҈� ᨨ ҈ ´  

  + 

ᨨ犨ᨨ�ᆠᨨ矄矄꾀

�´ =

 ´ =   + 

Þ黨㦨졔



҈ Þ= W  �



҈

㡰 ᨨ鼀 ⧤ 졔ᔼ҈졔҈ ᔼ�ᔼ㡰㦨



꾀泐� �  ᆠᨨ鼀� �ᨨ  ᨨ  �矄

E҈ E E + + ҈+҈  ҈ +҈ ҈ ҈ ҈ + + ҈ +҈  ҈+҈    + +    = �´  ҈ ҈ ҈  + +    ҈ = 㦨ᨨ 

 W 黨 ҈W

W

q

W

㦨ᔼ҈졔ᔼ҈ᔼ 錐ᔼ҈ᔼ㦨  ҈㡰 黨졔ᔼ ᔼ҈ᔼ㡰졔ᔼ㦨 ᔼ҈졔ᔼ㦨黨  㡰 졠 矄ᨨ� � ҈㡰  㡰 ᔼ҈㦨҈꾀

WWW.JEEBOOKS.IN

EBD_8341 PS-208

Physics

�ᆠ�ᨨ 턼 ᨨ矄� ᆠᔼ҈>ᔼ ᆠ㡰 꾀矄 ᨨ ᆠ盐  ᨨ犨矄  ᨨ盐�  鼀 EB  

 㦨  쟼 㦨   㦨  꾀㦨� 和ᨨ ᨨ � �  ᆠ 犨    ᨨ� 矄 A   D VA  VD 㦨 �

҈҈

҈

b㡰



�m

W

ᔼ

ᔼ҈

R

R

黨W

҈

ᔼ  矄 泐矄 ᆠᆠ�ᨨ �矄 盐泐ᆠ �   ᆠ ᨨᆠ盐  犨� ᨨ犨 ᨨ盐� �  泐 矄�鼀泐 � �   ᆠ�ᆠ盐�

ᨨ鼀 �鼀盐鼀ᨨ犨R  㦨R�   R㦨W \ R㦨W �㡰  �    ᆠ盐  ᨨ犨� � �    ᆠ�ᆠ盐� 꾀泐� � ⧤�ᆠ ᨨ 矄 犨⧤�   ᨨᨨᔴ쟼 ᔴ �� 졔㦨 Þ�㦨 \�㦨҈꾀 v ᨨ犨 ᨨ盐ᨨᨨ犨 ҈W ᔴ �

꾀졔҈맔҈㦨

\

҈

҈

盐矄ᆠ盐  ᔼ = ҈

b㡰

W �҈ A

æ V 㡰 V ö t÷ ´ t çQ H = R R ø è 

҈҈W

黨V  ´ t  Q 盐Q㦨mcDT㡰 R



 �㡰

ᔴ盐  ᨨ盐� AB �҈ =

 =   + 

ᔴ盐  ᨨ盐� AD � =

 ҈ = 黨 + ҈҈ �

矄� �⧤� 꾀ᨨᨨ

NV 㡰 㦨 ´ t (Q R µ l ) R

VB + �҈ 㡰 - � 黨㡰 = VD ҈  Þ VB - VD = 黨㡰 - 㡰 Þ VB - VD = ҈ - ҈ =   � ҈

꾀矄ᨨHἘ㦨m'cDT㦨 m㡰CDT

N V  ´t R

 ��㡰

҈䰘

㡰 W

�� � �⼄ �㡰泐 ��㡰

A

C

mcDT 黨V  ´ t ⏌ R ҈ 黨´  =   = ᨨ mc DT N V t ⏌  R  N

�

ᨨ N 㦨҈맔\N㦨 b㡰 ⼄盐� ᆠ�ᆠ盐�矄矄 ᨨ犨 �   ��盐

҈

C

� 黨W

RἘ 矄�矄 ᆠᨨ  犨�ᨨ  ᨨ盐 � �l \ ᨨ犨 �泐矄 � 㜠矄ᆠᨨ 矄'

鼀ᆠD 㦨

D

B

W W

�҈

W

�

F

E �

W



҈

R

R



D 

꾀矄ᨨH㦨mcD 㦨



W

R 矄�矄 ᆠᨨ 犨�

쟼 �泐矄 � t矄ᆠᨨ H㦨

W

v

B

㡰

    = 㦨 ᨨᔼ㦨 㦨䰘꾀   + 黨 ҈

B 

꾀㦨�

 ᆠ 矄盐  ᨨ � �  ᆠ ᆠᨨ矄矄 矄�矄 ᆠ矄 犨�  



A

ᨨ꾀맔҈㦨

黨W



R 4W E

\꾀㦨�

W

R

҈ ҈ ҈ R 㡰  R㡰 = + = R Þ Req = Req R  R R㡰 + R㡰

҈�



R

E 4W

� 

� 

� ҈

R

R

꾀矄ᆠᆠ�ᨨ�矄 盐泐ᆠ �  ᨨᆠ盐 犨� ᨨ犨 ᨨ盐� �

R E

W

R

R R

R

W

R

R

R

҈꾀

R

A

҈꾀 E W  ᆠ ␔ 矄ᨨ  � �

 ᆠ�ᆠ盐� 矄 矄  ᆠ  ␔ 矄ᨨ  � �  ᆠ ᨨ ᆠ盐 犨� ᨨ犨ᆠᨨ矄矄 W 矄�矄 ᆠ

W W

E 꾀

꾀

҈

B W

WWW.JEEBOOKS.IN

PS-209

Current Electricity ␔  ᆠ盐  �矄�盐�ᨨ 矄矄 ᨨ犨 �   ��盐

҈V  VP = V ᨨ VP = V

æ  ´ ö + 쟼⼄盐� 矄�矄 ᆠ ⼄㦨 ç è  +  ÷ø

VA  VQ = I ´ W = (҈A)( W)

҈V  VQ = V

҈ ҈ ´  = =  꾀鼀  ҈ + 

VQ = ҈V  V = V

�҈㦨꾀 �= ҈꾀 VAEB㦨҈맔졔맔㦨 ҈ 矄ᔼ    ᆠᨨ泐�ᆠ 矄ᨨ盐�ᨨ    ᆠ�ᆠ ᆠ盐  �矄 鼀� 泐 盐ᨨ 鼀ᨨ鼀 ᨨ �ᨨ 矄 ᨨᆠᨨ 矄 ҈黨 b 㡰 ᨨᆠ盐 �矄 ᨨ犨� � ᨨ盐� 矄�矄 ᆠR 꾀泐� � ⧤ �  ᨨᨨ

\ � =

҈ +   �㡰 ҈ + 

V  VS = V Þ VS = V

\VsVQ ҈

졔 II҈㡰졔҈졔҈맔I졔I㦨

Þ I҈�I㦨҈ A

1V



R

ᔼ

W

҈

矄�矄 ᆠᨨ  盐鼀

I

R⼄

I҈㦨⏌҈꾀 I㦨 �㡰

҈V \ I҈ = = A W æ ҈ ö I = ç ´  = A è  + ҈ ÷ø I = I҈  I = ҈A

ᨨ � �  ᆠᆠᨨ矄矄A P

VA  VP = I  ´ W = (  A)( W)

ᨨ � �  ᆠ犨 B D

 é� ù - ú ´  = VD \VB  BD㦨  ҈ ҈ ҈ ë û

VB졔 ê

W



( W )(҈W ) = W RR = ҈  = R҈ + R W + ҈W

 ��㡰

� 꾀 ҈

 ᆠᨨ矄矄G 㦨  -

 ᆠᨨ矄矄 H㦨҈졔҈맔

҈W

쟼⼄盐� 矄�矄 ᆠᨨ   ᆠ�ᆠ盐�

ᔼ҈

ᔼ㜠ᔼ҈

Þ I҈I㦨҈ 和ᨨ� �⼄ �㡰  ��㡰犨�

��㡰

R҈ = W + W + W = W



3W

҈ H

 黨 - ҈ ҈  ´= = ҈ ҈ ҈

᲼Q  ᆠ�矄�  �矄ᆠ �� �鼀ᨨ 桌

矄�矄 ᆠᨨ  ᨨ犨鼀

R = W + W + W = ҈W

1W

D

W



1W

C G ᔼ҈  꾀泐� �⧤�ᆠ ᨨ Ἐ矄 犨⧤�  ᨨᨨ BCDB 犨 �  II҈㡰졔҈졔I҈졔I҈㦨

F

W

B

E

F

V

A \ ҈ ҈졔҈ 㦨҈ ҈졔 ҈ Þ ҈ 㦨 ҈ ᔼ ҈㦨   ҈㦨 㦨  ᔼ ҈㦨   ҈㦨 㦨  ᔼ ҈㦨   㦨 ҈ ᔼ ҈㦨   㦨 ҈㦨   bᆠ 㡰 矄�矄 ᆠᨨ 鼀PQ STᆠᨨ鼀矄�  ᆠ�矄PQ S  T     矄鼀 ᨨ �  ⼄盐�  ᆠ�ᆠ盐� �矄 矄 矄 ᨨ犨 �   ��盐 W  和  W W I





ᔼ

2W

E

B

҈ ҈ +  = ҈ ҈ + 



 �㡰

R

 ҈ - � ҈ =  \ � =  ��㡰 ҈



꾀泐� �⧤�ᆠ ᨨ Ἐ矄 犨 ⧤ �  ᨨᨨ BDAB





꾀泐� �⧤� ᨨᨨᔴ쟼

ᨨ鼀⼄ �㡰 ��㡰

VP  VS = (  A)( W ) = V

D �

C

҈ - � ҈ +  - �  = 

ᨨ � �  ᆠᆠᨨ矄矄P S

2W

ᆠ盐  � =

ᨨ � �  ᆠᆠᨨ矄矄A Q



I

҈

�㡰

 ҈黨 =  ҈ ҈ ᲼Q ᆠ�矄� ᆠ �� �鼀ᨨ 桌

和� ᆠ ᨨᆠ盐 �矄├  ᨨ鼀 泐

E҈ E E + + r҈ r r SE ⏌ r = \ VAB㦨E⼄㦨 ҈ ҈ ҈ ҈ S + + r r҈ r r

( ҈ + ҈ + ҈҈ ) = V 㦨 ҈ ( ҈ ) + ( ҈҈ ) + ( ҈҈ ) ᔼ  矄�矄 ᆠ ᨨ ⼄盐� 泐㦨

�҈ =

҈ W 

VB  V A + E҈  +  = = ҈A r҈ ҈

WWW.JEEBOOKS.IN

EBD_8341 PS-210

Physics

� =

VB  V A + E  +  = = r ҈

 � =

VB  VA + E  + ҈ = = ҈A r ҈



b㡰

�

㡰

��㡰 ᔼ  r �矄 矄 ᨨ㜠ᆠ�ᆠ盐�     矄�矄 ᆠ ᨨ   �矄  ᆠ  �

ᨨ r҈ Q P I҈ E҈ A

R U

E

I I

I҈졔I졔I

T

r

E

R

҈ = �  ҈ =

B

S

꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 �  PQRUP 矄� � ᨨ鼀 P 鼀ᨨ� � ᆠᨨᆠ├犨�矄 I҈r҈ E҈졔E㦨ᨨI҈졔㦨 \I҈㦨҈꾀 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 �  URSTU 矄� � ᨨ鼀 U 鼀ᨨ� � ᆠᨨᆠ├犨�矄 E졔EIr㦨ᨨ졔҈I㦨\I㦨҈꾀    矄��  ᨨ  I � �ᆠ矄     �ᆠ�ᨨ  ᨨ  ᆠ盐  �

 ᆠ  UTSR �矄 ᨨᨨ矄�ᨨ   矄矄盐鼀  꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 �   AURBA 矄� � ᨨ鼀 A 鼀ᨨ� � ᆠᨨᆠ├犨�矄 I҈졔I졔I㡰RE㦨ᨨ



䰘



黨 ҈

æ ҈ ö ´ Pᨨ矄矄 = I  R = ç è  ÷ø

P ᨨ犨P㦨VI Þ I = V ҈� ´҈�� +  \ I 鼀� = = ҈黨 A »  A  

b㡰

R ´ R  R ´҈ R +R+ + R 㦨R졔R졔R졔R㦨R R + R  R + ҈ R

V ҈ 矄� �P㦨 R Þ㦨 ⼄ R R㦨

҈ 㦨W ´

 ҈ Þµ

ᆠ㡰   �泐 犨�  鼀 �鼀盐鼀 犨   矄�矄 ᆠ 犨�  鼀� �鼀盐鼀 ᆠ㡰 ᨨ ᨨ犨 ᆠᨨ 矄盐鼀  泐 ᆠ�ᆠ � ᆠ矄 �    盐� � �ᨨ㦨�␔ ␔㦨 ᨨ맔 鼀 �㦨V맔IÞ�㦨IÞ I =

� = ҈҈ »҈꾀 

㝐� �鼀盐鼀 ᆠᆠ�泐ᨨ  鼀�  盐矄㡰 ҈҈

ᆠ㡰

ᔴ盐 � ᆠ 盐㦨

ᨨ犨 ҈ = �꾀 㦨 ᨨ� 

ᔴ盐  ᨨ盐� 鼀鼀㦨�맔㦨҈�꾀

㦨 W 턼㦨W ҈

b㡰

ᔼ҈ 꾀 ᔼ

쟼⼄盐�  矄�矄 ᆠ

R⼄㦨

\

ᆠ㡰 ᨨ鼀  �� ᆠ�ᆠ盐� 矄�矄 ᆠ矄 ᔼ㦨҈W ᔼᔼ㦨҈⏌W ᔼᔼᔼ㦨⏌W ᔼ�矄ᆠ  > ҈>   ᆠ҈

Þ

҈ ´ ҈ = 黨奠 \쟼 �ᆠ� ᆠ泐 = ҈ + Pᨨ矄矄

e ⏌㡰

 ҈҈ ҈҈ ´ ´҈  =҈҈´҈ � ␔ 㦨 ҈҈ ҈҈

꾀矄ᨨ犨 㡰 =



㡰 ᨨ犨P 㦨҈�맔�졔҈�맔҈졔҈�맔҈졔맔҈ 㦨҈�맔҈��졔␔

e e = ⼄ 

ᨨ'㦨㦨␔ Q㦨␔㡰 㡰 ᨨ犨㦨ᔼ 㦨맔҈맔 Þ 㦨҈҈맔҈W ␔  矄盐泐ᨨ ҈҈�矄ᆠᨨ

ᆠ ᨨ犨㦨

R = W V =  



 㦨҈␔ �

和�鼀�泐㦨� 㦨  ␔ b㡰 ␔   犨ᨨ矄�矄 ᆠ矄ᆠᨨ

ᆠ � 矄�矄 ⼄㦨

犨 ᨨ犨  ¢ =

b㡰 ෌� ᨨ犨P㦨҈├␔㦨҈␔

P ҈ = V 

æ   ö ç � + ҈ ÷ è ø

´

ᔼ ᆠᨨ ��ᨨ  ⼄ 㦨 ⏌

Topic-4 : Heating Effect of Current

ᔴ盐  I =



ᨨ犨ᆠᨨ 矄盐鼀   =

҈졔I҈㡰R 㦨\I㦨꾀

 ᆠᆠ盐  ᨨ盐� R㦨I҈졔I졔I㦨꾀

҈

    矄ᨨ ҈ =    =  � ҈  ᔴ盐  ᨨ犨 � = ҈ +  꾀矄 =



㦨҈W 和㦨W ҈㦨졔턼㦨W졔W㦨W 㦨 졔和㦨҈W졔W㦨W ᔼ҈ ҈㦨ᔼ 

ᔼ҈ =

 ᔼ  ᔼ = ᔼ =  ҈  

ᨨ ᔼ = ᔼ҈  ᨨ犨㦨ᔼ 

WWW.JEEBOOKS.IN

PS-211

Current Electricity

æ R ö ÷ 㦨䰘IR  ø

ᔼ   ᨨ턼  턼 = ᔼ҈ 턼 =  ´  = ᔼ  

ᨨ犨 �矄矄��ᨨ P㦨I çè



   ᨨ和  和 = ᔼ  和 = ᔼ  ×  = ᔼ  

R

\ ෌矄鼀ᨨ盐 ᨨ  �  泐和 ҈

㡰 ␔├ ᨨ犨ᨨ犨 P =

ᔼ �矄 ��      ᨨ犨矄 ᨨ    盐矄  �    ᨨ  ҈␔>␔>␔

\

R҈

ᔴ矄 �㡰

1W 1W



㡰 \

2W

2W

1W

V V \ R㦨 P R   V V  R = = R 錐 R҈㦨 ҈ 

꾀矄犨├ ᨨ犨P㦨

R



V V㦨 VR  R ҈졔R 

V҈㦨 VR ҈ R ҈졔R 

�矄�矄ᆠ矄ᨨ  ᆠ ␔ 矄ᨨ � �R҈㦨҈W ᔴ矄 ��㡰

R

1W

�

1W

�㡰 W㦨 V 㦨 R3 R

2W 1W

1W

㦨�

҈

҈ ҈ ҈  = + + Þ R = = ҈  �   ҈   R

W҈㦨

V҈

=



ᔴ矄 ���㡰

1W

  W =

1W

2W

2W

ᨨ

1W

1W

㦨

盐矄R㦨W 和� ᆠRR҈R\P>P҈> P 꾀矄犨├ ᨨ犨P㦨IR ᔼᆠᨨ 矄 \P µ R

I

R R R ᨨ犨 �矄矄��ᨨ  P҈ 㦨 I  R㡰 㦨 I  R R

ᨨ

�㡰  V

R ҈䰘

V R

´  

R 

�㡰  �㡰  R �㡰 R R҈  R R҈ + R 㡰 R҈ + R 㡰 �㡰  

´

�㡰V  V    é ҈ ҈ù  êë҈ +  úû V ´ ҈

҈ ´ ҈ ´  ´  ҈ ´ ҈ ´  ´   ҈ ´ ҈ ´  ҈ ´ ҈ ´ ҈

㦨�҈�

 ᨨW҈WW ᆠ㡰 I҈맔�㦨I 졔㡰

I I

V V  R = R R҈ + R 㡰 



҈ù  é ҈ êë҈ +  úû V WWW҈

R

I

R҈ + R 㡰

 W㦨 

WWW҈

㦨

I

V  R҈

WWW҈㦨

1W

㡰





2W

1W

҈�



1W

1W

1W

æ ö R÷ 㦨҈� IR  ø

\ᔼᔼᔼᔼᔼᔼᔼ

1W 1W

1W

҈ R ҈

1W

R⏌

ᨨ犨 �矄矄��ᨨ  P㦨 I  çè

꾀 V�矄ᆠᨨ 矄 �  ᆠ矄矄 \ P µ

1W

I

R

R

V ␔ ├ ᨨ犨ᨨ犨 P = R

҈ ᆠ㡰

R I

҈ ҈ > R R

>

R/3

R ᨨ犨 �矄矄��ᨨ  P㦨 I ( R ⏌ ) 㦨I  R

҈ \ ᨨᆠᨨ 矄 �ᆠ盐鼀盐 P µ R

҈

I

R

I

V R

W

W

I

I

R



�W

WWW.JEEBOOKS.IN

EBD_8341 PS-212

Physics

I҈ \I҈㦨IÞ I  =

 �  � �W 矄�矄 ᆠ矄ᆠᨨ I҈ ´ � = �  � W 矄�矄 ᆠ矄ᆠᨨ I҈ ´  

Þ

҈

�矄犨ᨨ盐 ᨨ矄矄�ᨨ 泐犨  R㦨W�矄� 矄�矄犨�   盐矄�矄 ᆠ R盐㦨W㡰ᆠ盐矄�  ᆠ矄ᨨ 矄�矄 ᆠ矄 犨�矄 ⼄盐 ᨨ ҈ᆠ  ҈

҈ ҈ = � Þ H� W = =  ᆠ⏌矄 H� W �

犨  = r

\ �  �  W矄�矄ᨨ㦨ᆠᨨ�矄⏌矄 b㡰  ᨨ 盐ᆠ   矄ᆠᨨ

H=



V  R = R ö

ò

é rl ù 㦨  ´ = ú   ë p û

ᨨ矄�矄 ᆠ㦨 ҈졔 㦨  ê

æ ö rl \ H = V ç pr ÷ l =  è rl ø A pr 

\  =

æ pV r r H =ç ᨨ H µ ÷ l l r è ø

ᨨ



㡰

 ´  ⏌

ᨨ矄�矄 ᆠ 㦨

ᔴ矄ᆠᨨ

ᆠ � 矄�矄 R

R

\  =

 r

E

r

æ E ö J҈ = I  R = ç R è r + R ÷ø R

R

矄�矄 ᆠᨨ   ᆠᨨ�R 㦨

\

E

r

ᔴ盐 �  ᆠ�ᆠ盐�㦨 I 㦨

r 

A



æ E ö J = I R = ç ´R r÷ çR+ ÷ è ø  E 㡰



r + R 㡰 Þ

R = �

 r + R 㡰

=

rö æ çè R + ÷ø 

R



҈



\

R盐㦨

㡰 ᨨ鼀ᨨ 矄�矄 ᆠ҈├W�矄ᨨ 矄�矄 ᆠ ᨨ W和ᨨ �⼄盐� 矄�矄 ᆠ�矄

᲼Q = ҈W桌

V ҈ ´ ҈ = =  W P �

҈ ҈ ҈ ҈ ҈ = + = + R Ἐ ҈ k W W ҈ 

R

盐

V ᨨ犨P㦨 R

R

V Ἐ = I  ´ R Þ �㦨�맔R \R㦨�W

Þ R졔�㡰㦨҈� 졔R㡰\R㦨W W W㡰␔ ├ ᨨ犨 



Topic-5 : Wheatstone Bridge and Defferent Measuring Instruments

Þ ᲼ R + �桌 = �᲼ + R桌 

V 䰘� = = 䰘� A R ҈

҈ ᨨ鼀 졠 鼀Ἐ矄犨 矄�矄 ᆠ ᆠᨨ矄矄矄�矄ᨨ R



r R + 㡰  �

B ҈W

෌� 㡰

E

V  ҈ ´ ҈ = 㦨҈W P ҈

�矄 ᆠ盐  �� 矄 � ᨨ 犨ᨨ 矄  I҈    ᆠ盐    矄矄矄  ᨨ盐�     \V'㦨I҈ Þ�㦨I҈맔҈\ I҈㦨�A

盐矄ᆠ盐  ᨨ盐� 矄�矄 ᆠἘRἘI㦨䰘��㦨�꾀

I r

\҈㦨�

 ���㡰

\ V'㦨 ´  Ἐ = ҈ ´ � = � = � 和� ᆠ   ᨨ� ᨨ ᆠᨨ矄矄    �矄 �V  ᆠ ᨨ� ᨨᆠᨨ矄矄҈W矄�矄ᨨ�矄 ҈�㡰㦨䰘�V

ᔴ矄ᆠᨨ

ᆠ � 

E

 ´  ⏌

ᨨ� ᆠᨨ矄矄   ᆠᨨ� ᨨ   �  � ᨨ矄 犨�   ᨨ犨 P Ἐ㦨�␔

E r



E

҈   ⏌  = ҈ = = ҈ +   ҈  

ᨨ鼀⼄ �㡰  ���㡰㦨�鼀�

I

E

 ��㡰

ᨨ鼀⼄ �㡰  ��㡰㦨鼀�  ␔   矄�矄 ᆠᆠᨨ

ᆠ � 

盐矄  ᨨ  H㡰�矄 ᨨ盐 � ᨨ  �  l㡰  �盐矄 r㡰 ᨨ盐  ҈黨

l rl =  꾀 p

␔   矄�矄 ᆠ矄ᆠᨨ

ᆠ � 矄�矄





æ  ö   = ´   �㡰 ÷ è ø

b 㡰 ᨨ 盐ᆠ   = ç

Þ 

҈ ҈ + �  ҈ = = Þ RἘ = W R Ἐ ҈ ҈ 

矄� �졠 鼀Ἐ矄犨ᆠ盐 �  ᆠ�ᆠ盐�

I=

ᨨ�  =  矄�矄 ᆠ ҈ +  

WWW.JEEBOOKS.IN

PS-213

Current Electricity ᨨ � �  ᆠ 鼀矄盐 泐ᨨ鼀

҈�  ҈ ÞV = 㦨҈黨�ᨨ V = IR Ἐ = ´ ҈  䰘䰘 +   

b㡰 㝐盐�鼀 矄 ᨨ犨矄  ᆠ�ᨨ  �  ᨨ  ᆠ矄矄 �  ᨨ   矄� � ᨨ矄�  ᆠ ᨨ矄  ᆠᨨ鼀ᨨ  �矄ᆠᆠ�ᨨ



㡰 ᨨ �� �  x =

黨

҈



b㡰

ᨨ ᆠ 鼀� �

 Ӹ ÞӸ㦨黨�㦨맔 ҈黨�㡰 = 黨� ҈ - 黨�㡰 ҈� ´ 黨� ᨨ  = = ҈ W �

ᨨ � ᨨ  �

҈ =  ᨨ⏌ᆠ鼀 ҈ - 黨

矄� � ᨨ鼀盐 �  矄�矄 ᆠ

æ l -l ö � -  ö r = ç ҈  ÷ s = æç ÷ ´ � = ҈�W l è  ø è  ø

ᨨ � ᨨ㦨҈  ᆠ� � �  ᨨ鼀㦨҈黨

\x =

b㡰

҈҈

␔      Ӹ  � ᆠ  �  l҈   ҈  l҈㡰 犨� 矄ᨨ � ᆠ  �矄ᨨl㦨�ᆠ鼀 㡰  �矄 ᨨ ᆠ  � �  盐ᨨ�  �    ᆠ    � ᨨ鼀 ᆠ  � �  ᆠ 犨 矄ᨨ � �



   矄�矄 ᆠᨨ  犨 ᨨ犨� ᨨ � � �  ᨨ  ᨨ �ᨨ鼀 犨�

졠  ᆠ� �ᆠᨨ ��ᨨ 

dV I ´ R é  ´ R ù = = ê ú mv ⏌ m dl l ë l AB û æ dV ö  ´ R =ç lAP = ´ ҈mV ÷ d l ҈ è AB ø

꾀  ᆠ  �

Ἐ AB Ἐ = V AP

R҈ R = R R

ÞVAP㦨� mV 꾀矄ᨨVAP㦨�V ᨨ ᆠᨨ� P㡰

\R = �

V AP � ´ ҈ 

=

� = ҈W � ´ ҈ 

 矄�矄 ᆠ ᨨ  ᨨ �ᨨ鼀 犨� 㦨҈맔㦨W ᔴ盐 �  犨� ᆠ㡰

�=

 ҈ V = = A RT  + � + �䰘 + ҈ 

҈ ᨨ犨V㦨�R 꾀㦨 맔 ҈맔�㡰㦨�   䰘

㡰 ᆠ㡰    � 꾀犨 �ᆠ � ᨨ鼀矄 ᨨ犨矄 盐  ᆠ�ᨨ  ᆠ盐 

�=

 e æ ö e = ᨨ � ç ҈ ÷ = ҈ +  ҈ è ø 

e é e é ù e ù e ҈ Þ ·҈ ú =  Þ ê ·҈ ú =  ᨨ 㦨  ҈ êë   ҈ û ë û 

졠  ᆠ� �ᆠᨨ ��ᨨ 

㡰 ෌� ᆠᨨᨨ盐 ᆠᨨ ᨨ  矄�矄 ᆠ ҈㦨졠 �   ᨨ犨

\ ҈㦨맔҈㦨 盐矄� �  ᆠ  犨 矄ᨨ  � � � ᆠ�

҈    = Þ =    

\ 㦨҈�ᆠᨨᨨ盐ᆠᨨ  ᨨ ᨨ犨 盐 ᨨ犨

҈

R҈ R = R R

ᆠ㡰 꾀矄   犨ᨨ ᆠ矄 ᨨᨨ矄 ᆠ  ᨨ   ᆠ    ᆠ� 鼀 � ᆠᨨ矄 ᆠ�ᆠ盐� �矄 ҈�  ҈ 㦨 �     矄�矄 ᆠ �矄 ҈ 졔  㦨 ҈ W ᆠ盐矄 �    ᆠᨨ矄  ᆠ�ᆠ盐�   �   矄�矄 ᆠ ᨨ  犨ᨨ ᆠ矄  �  矄�矄 ᔴ盐  �    ᆠ�ᆠ盐� I 㦨

 ᆠ� 鼀 � A = ᨨ 矄�矄 ᆠ ҈

 ᨨ � �  ᆠ ᆠᨨ矄矄 ᨨ鼀 犨�  矄鼀 矄   鼀�  ᨨ� ᨨ  �  ᆠ 和� ᆠ   ᆠ盐  �矄 犨  ᨨ鼀   ᆠ ᨨ   ҈�  \ V҈ 㦨 E҈  Ir҈     㦨 ҈�  ҈ ᆠ㡰

� ´  = ҈҈  ҈

ᔼ ᆠ矄ᨨ  ᆠ 鼀� �

R X = ෌� X㦨黨Wl㦨ᆠ鼀 l ҈ - l 黨 ´  Xl = = W \ R =  ҈ - l DR Dl D (҈ - l ) = + \ ҈ - l R l DR ҈ ҈ = + \ DR = �W Þ   

 ᨨ R = (  ± � ) W

WWW.JEEBOOKS.IN

EBD_8341 PS-214

҈

Physics

b㡰

҈W



R҈ A

x R

G C

R R

B

ᔼ   �盐矄ᨨ    犨� �矄 ᨨ盐       矄�矄 ᆠ ᨨ  AC 犨�

R ᆠ  � 矄ᨨ 矄�矄 ᆠᨨ CB 犨�ᆠ  �盐矄� ᆠ ҈ ᨨ矄





�ᆠ鼀

ᆠ鼀

P R = 꾀泐� �  ᆠ  犨 矄ᨨ  � � ᆠᨨ ��ᨨ  Q S X ҈ = l҈ l   l҈ 㦨�졔 ᆠᨨᆠ�ᨨ 㦨�졔҈㦨�ᆠ鼀

R

ᨨᆠ  �矄ᨨ ҈

l  㦨졔 ᆠᨨᆠ�ᨨ 㦨졔㦨�ᆠ鼀 ᨨ ҈�

X ҈ � = \ X = = ҈W � � �

P R = 꾀泐� �  ᆠ 犨 矄ᨨ  � �ᆠᨨ ��ᨨ  Q S R㦨W

l

҈㜠l



G

҈黨

S

R



꾀矄␔ 矄ᨨ � � ᆠ ᆠᨨ ��ᨨ 

҈ R Ἐ Þ�졔�R㦨҈R ҈� ҈ R Ἐ  Þ �= = + ҈ R Ἐ ҈ + R Ἐ ҈ �  \ RἘ = = ҈W �

␔     矄�矄 ᆠ矄  � ᆠ  �    ᨨᆠ├泐 矄 � 矄 ᆠ鼀

 X = ÞX l X㦨 l 졔 l +   - l æ  ö ᨨ X㦨 l X졔㡰졔㦨 çè ÷ X + 㡰 +  X + ø  ᨨ X㦨 㦨W 

\

\



E ҈ = k �㡰 r + ҈

G

r + ҈ � = Þ�r졔�㦨� ҈ � N  Þ r = W = W ÞN㦨҈ � ҈ Þ

S

矄� �IgG㦨 IIg㡰S

æ G ö = ҈ ´ ҈- æ ҈ + ҈ö +҈ çè ÷ è S ÷ø  ҈ ø

I㦨ᔼ� ç ҈䰘

 ��㡰

�� � � �㡰泐 ��㡰犨� I㜠Ig

ᨨ 㡰

҈㡰 ␔ ├ ᨨ犨  

E µ l 犨 l�矄  ᆠ� � � \쟼㦨k �㡰  �㡰 ␔    ᆠ� � � ᆠ  �矄泐ᆠ鼀

 Ig 㦨҈맔҈A錐 G㦨҈W; S㦨҈W I

P S = Q R

 矄�矄 ᆠ  �矄 ᆠᨨ

ᆠ  �   犨�  矄�矄 ᆠ 和 ᨨ ҈W

 ᨨ ҈RR l 㦨 l X ᨨ  l 㦨 l Xᨨ l 㦨 X +

Ig

B

҈㡰

B

㡰

G

㜠l

l졔

R X = l ҈ - l

҈

Q

P

㦨W



X

 ᨨ� C ᨨ矄 ᨨᆠ  � 㡰 和� ᆠ ᨨ � �ᨨᆠᨨ矄� �  矄犨�ᆠ �s ᨨ矄 ᨨ ᨨ矄 ᨨᆠ  �   � �ᨨ � ᨨ鼀�鼀 矄  �  ᨨ  ᆠ矄矄 �矄 ᨨᆠ盐  矄矄� � ᨨ盐�  S ᔼ �矄   ᆠ矄 ᨨ  ᆠ  犨  矄ᨨ  � � 盐矄 ᨨ �A �矄⼄盐ᨨᨨ �B

\ IP㦨IQ IR㦨IG

␔   � ��矄 ᆠ x>W

㡰

AC 矄 ᨨ盐 矄ᨨ ᨨᆠ  � 盐ᨨ�   ᨨ A CB

I㦨҈맔҈맔҈҈㦨҈҈鼀꾀 ᔼ ᆠ矄ᨨ 鼀� � 盐ᨨ� 

R҈ R AC AC = = = R R CB ҈  CB

҈

䰘㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  矄�矄 ᆠ  矄 鼀盐 ᆠᨨ �ᆠ� a 㦨 ᔴ҈ 꾀 鼀盐�矄� ᆠ矄 泐҈ ᔴ �D 㦨҈ ᔴ Ἐ㦨  ҈졔aD 㡰㦨 ҈졔aD 㡰 \ Ἐ㦨҈W

WWW.JEEBOOKS.IN

PS-215

Current Electricity

R҈㦨W

ᔼ

ᔼ

R㦨҈W

QV = IR 㡰

黨㦨I 졔㡰ÞI㦨҈A

 m

 m





�

 �  � =  ᔼ = = ҈ +  䰘  +  

W

W

� � - � ´ 㦨҈黨҈䰘㦨䰘 䰘 

 ᆠᨨ� ᨨ 犨 和  㦨䰘ᨨ  㡰 ␔     鼀盐 ᨨ 鼀 � ᆠ矄矄錐 �矄 矄�矄 ᆠ � ᆠ矄矄Rt㦨R ҈졔µt㡰  ├ ᨨ犨 矄�矄 ᆠ㡰 和  矄�矄 ᆠ㡰 X S

黨 ᨨ � �  ᆠᆠᨨ矄矄W矄�矄 ᆠ 㦨V ᨨ � �  ᆠᆠᨨ矄矄W矄�矄 ᆠ 㦨 \  ᆠᨨ矄矄ҘFᆠᆠ�ᨨ㦨V   ᆠᨨ矄矄ҘFᆠᆠ�ᨨ㦨V \ ᔴ �ᨨ ҘFᆠᆠ�ᨨQ҈㦨맔㦨黨ҘC ᔴ �ᨨ ҘFᆠᆠ�ᨨQ㦨맔㦨ҘC \ ᔴ � ᨨ犨矄 ᨨ鼀yᨨx㦨黨㦨䰘ҘC b㡰 꾀矄ᨨ 犨�ᨨ 矄鼀鼀�\ᔼ꾀㦨ᔼᔴ \

和 㦨҈ᔼ҈�ᔼ 㦨 ҈ ´

졔턼 턼

R㦨�W

RἘ = ҈W  ᔼ = ҈

졔턼҈ 턼҈



r









N

 l⏌

l⏌

r l

҈

l

㡰

J G

\V AB =

ᨨ鼀� � 盐ᨨ� ᨨ ᆠ ᆠᨨ ��ᨨ

X S X l = = ᨨ l ҈ - l S ҈  l ᨨ 盐ᨨ� ἘἘ矄鼀ᨨ�  ᨨ 盐 ᆠ  �  

l҈ ᨨ鼀�

҈ - l �

\

� ᆠ矄� �  矄   矄�矄 ᆠἘsἘ矄 ᨨ盐 矄ᨨ� ᆠ矄 ᨨ矄��ᨨ 㜠ᨨ  盐ᨨ� ��矄鼀ᨨ矄ᆠᆠ盐 � �盐ᨨ�  �矄鼀ᨨ矄 ᆠ ᨨ 矄�矄 ᆠ犨�犨 矄ᨨ � � �矄鼀ᨨ矄ᆠᆠ盐犨    ᨨ盐矄�矄 ᆠ矄ᨨ   ᨨ盐鼀矄 ᨨ  矄鼀ᨨ ᨨ 鼀� �盐 

ᆠ㡰

P X =  Q R

㡰 ᨨ  ᨨ ᨨ矄��   �� 鼀� 矄 ᨨ    � ᨨ鼀␔     �矄 ᨨ ᆠ盐    ᨨ�  ᨨ    � ᨨ鼀�矄 ᨨ 㡰 C  X A D Ý ҈W ᆠ㡰Q � ��矄 ᆠ 

R AJ  r ҈ W = = \ X 㦨W RJB  r X

犨 r�矄 矄�矄 ᆠ盐 � � 

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈

㡰

X 矄 ᨨ盐 矄ᨨ鼀� 盐 ᆠ  �  ᆠ� X�矄 S

G

VBC  

ᔼ ᆠ矄ᨨ  ᆠ 犨 矄ᨨ � �ᆠᨨ ��ᨨ  

VAB I AB R AB R = = AB = VBC I BC RBC RBC

ᆠ㡰 ␔   矄犨�ᆠ 和�矄ᨨ ᨨᆠ �Q҈졔Q㦨CV҈졔 CV㦨맔졔 맔㡰㦨␔   矄犨�ᆠ �矄ᆠᨨ矄  矄 泐矄�矄ᆠ   ᆠ盐 I ᆠᨨ鼀� � ᨨ鼀 泐�矄







PBC I RBC = = PAB I  RAB

r

l ᲼p ´ r  桌 ҈ = l  r ᲼pr  桌

l ᲼p ´ r  桌 ҈ = l  r ᲼pr  桌

PAB㦨PBC

I J AB p ´ r  ҈ = = 錐 \JBC㦨JAB I J BC   p´r éV AB ù E AB êë l ⏌  úû ҈ = = 錐 \쟼ᔴ㦨EAB E BC é VBC ù  ê l⏌ ú ë û

b㡰 ᆠ  �� �   �泐㦨 矄盐� � 㦨DU = Q = I2Rt 㦨҈맔҈맔҈맔�맔㦨㦨├ 㡰 꾀  泐 � 矄  ᨨ  �鼀 t 盐� � ᆠ �� � ᨨᆠ矄矄    矄� ᆠ盐 �  ᆠ�ᆠ盐�

V -t ⏌ RC e \ ᨨ � �  ᆠᆠᨨ矄矄矄�矄ᨨ R é V -t ⏌ RC ù VR = ê e ú´R ëR û

I㦨

= Ve - t ⏌ RC

\

Q

ᨨ � �  ᆠᆠᨨ矄矄 C Vc㦨VVet/RC 㦨V ҈et/RC㡰

Vc = VR

 �㡰  ��㡰

WWW.JEEBOOKS.IN

EBD_8341 PS-216

\

Physics

(

)

\ �鼀ᆠᨨ 矄  t 㦨RC㦨矄ᆠ ᨨ �ᆠᨨ矄矄 m  ᆠᆠ�ᨨ -t ù  泐�鼀� é

V ҈ - e -t ⏌ RC = V e - t ⏌ RC

Þ ҈et/RC 㦨et/RC  Þ ҈㦨et/RC

V = V êë҈ - e t úû

├� �ᨨ�ᨨ ᨨ 矄� 矄

æ t ö ᨨ�e҈㦨ᨨ�e졔 ç è RC ÷ø t Þ 㦨맔ᨨ�҈ RC Þ t㦨᲼맔ᨨ�҈桌맔�맔҈맔맔҈ᨨt㦨҈矄 �

b㡰

é

Þ  = ҈ ëê҈ - e Þt㦨矄 Þ e

 ҈

ᔴᨨ鼀� �犨� y㦨mx 졔C

҈ æE ö ᔼ ᆠ㦨ln ç  ÷  矄ᨨ㦨 è Rø RC



䰘 

和ᨨ犨   x �矄 ᆠ  � ᨨ x    矄ᨨ � ᆠ矄矄   ᆠ盐  ᆠᨨ鼀矄矄矄 ᆠ 犨� �矄Q b㡰 ᨨ矄ᨨ �ᆠ ᨨ �矄矄ᨨ犨ᨨ├矄 ᨨ  � ᆠ� ᨨ  ᆠ 犨  矄ᨨ  � � 盐矄 ᨨ鼀矄盐 盐 ├ ᨨ犨  矄�矄 ᆠ ᨨ   矄�矄 ᆠ犨� ᨨ矄�矄 ᆠᨨ 犨 ᨨ � ᨨ ᨨ ᔼ矄 ᨨ盐 ᆠᨨ

ᆠ 犨 A D ᆠ㡰 꾀矄  ᆠ盐 ᔼ�矄�    ᨨ  R �  ᨨᨨ犨矄     矄�矄 ᆠ R ҈ R   R  R    R  鼀盐矄 ᨨ鼀    ᆠ ␔ 矄ᨨ � �\R҈R 㦨RR b㡰 R 矄�矄 ᆠᨨ 犨� 쟼 �泐矄 � t矄ᆠᨨ H㦨 꾀矄ᨨH㦨mcD 㦨

҈ �㡰

æ I - Ig ç Ig è

ᨨ鼀 ç

҈

⼄ 㦨

ᔴ ҈ - 

҈ 錐V µ 錐V µ r  r r

-

ᔴ

ᔴ



 �҈ =

㡰

  - ᔴ    - ᔴ  

㡰

 �  =

Ҙ   㦨 ᔴ

㦨�KW



 ᔴ㦨Ҙ

- ᔴ҈ é ᔴ ù 㦨 ê҈ -  úû 㦨 ë ᔴ

�ᨨ 

҈ V ᨨr  P µ (Q V = ᆠᨨ 矄  ) R R

꾀矄 ᨨ�ᨨ �矄 ᨨ 㜠盐 � ᨨ鼀 ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ 犨�  �    �   ᆠᨨ矄矄㜠矄ᆠ�ᨨ   ᨨ 鼀盐 �矄�盐�ᨨ  犨�  ᨨ 㜠盐 � ᨨ鼀  �鼀  犨�├    ᨨ� 犨   鼀盐�矄鼀 �鼀盐鼀



ö V -R ÷S = ÷ I g ø

㡰 ⼄盐� ᆠ�ᆠ盐�ᨨ  �� ᆠ�ᆠ盐��矄矄矄 ᨨ犨 ᨨ犨 R㦨҈㝐WC㦨m

-

盐 꾀    ᨨ � �鼀 ᨨᆠ盐  ᨨ犨矄 矄� ᆠ ᨨ  ᆠᆠ�ᨨ  ᨨ鼀 ᨨ ᨨ ᨨ犨 ᆠ盐  ᨨ ᨨ犨 ᆠ 㡰 ␔�  盐矄ᨨ  �鼀   ᨨ�ᨨ � ᨨ   �鼀  犨�ᆠᨨ鼀 �

 泐 ᆠ矄� � ᨨ ᆠᨨ矄矄㜠矄ᆠ�ᨨ

 � ᆠ矄� � 矄�矄 ᆠ  ᨨ  �鼀 犨�ᆠᨨ 矄盐鼀 矄矄ᨨ犨ᨨ犨 矄  ᨨ �  꾀矄 ᨨ犨 P =

҈

黨 ҈� -   n  =� ´ = - 黨黨 \ n = 黨  黨  ҈҈

ᔴ ҈ - 

éQ � = �  -  t ù ᨨ ëê ûú ҈ �꾀  ҈矄ᆠ盐  �  鼀鼀ᆠᨨ鼀矄 ᨨ    � �� e

N 㦨҈맔\N㦨

ᔼ  矄�泐ᨨ ��  Iµ

⼄҈ 㦨

�꾀 �鼀 㦨  矄ᨨ鼀犨� �矄泐 � �졠

mcDT 黨V  ´ t ⏌ R ҈ 黨´  =   = ᨨ mc DT N V t ⏌  R  N

㡰

bᆠ 㡰 꾀 㦨 � 矄 矄ᨨᨨ 矄   ├泐 �矄 矄矄  ᔴᆠ�ᨨ矄 ᆠ 矄 矄 ᨨ ᆠ�ᆠ盐�   ᨨ鼀 �矄泐  � �� 꾀㦨µ� ᨨ ��鼀ᨨ ├泐矄矄ᔴᆠ�ᨨᆠ矄矄 ᨨ  ᆠ�ᆠ盐�   ᨨ ᆠ盐  ᨨ犨矄  ᨨ盐�  ᨨ鼀 Q 泐 ��  矄�矄 ᆠ ᨨ  ᨨ鼀㡰 矄ᨨ � �矄泐졔�

꾀t㦨҈矄ᆠ�㦨

�� � �⼄ �㡰泐 ��㡰

Þ t =  ( l �  l ) = �

\  D 㦨�맔 졔

 �㡰

 ��㡰

҈

 �

�

꾀矄ᨨHἘ㦨m'cDT㦨 m㡰CDT

黨

t = l   l � 

�├W

NV 㡰 ´ t (Q R µ l ) R

N V  ´t 鼀ᆠD 㦨 R

=  =

�



ᨨ

t

V 㡰  æ V ö t÷ ´ t çQ H = ç R R ÷ø è

黨V  ´ t  Q 盐Q㦨mcDT㡰 R

t ù û ú

�҈

RἘ 矄�矄 ᆠᨨ  犨�ᨨ  ᨨ盐 � �l \ ᨨ犨  �泐矄 �  㜠矄ᆠᨨ 矄' 㦨

-

├� �ᨨ�ᨨ ᨨ 矄� 矄

ᔴ盐 � RC ᆠ�ᆠ盐� I㦨Iet/RC

æ -t ö t + lnI  ᨨ lnI㦨lnI ᨨlnI㦨 ç è RC ÷ø RC æE ö æ -t ö + ln ç  ÷ lnI 㦨 ç è RC ÷ø è Rø

m

҈㝐W

æ è

␔    �鼀 鼀盐�矄 ��  ç l n µ ҈

҈ö ÷ �鼀�矄��  Tø

ᨨ ᨨ犨犨 � ᨨ ��  ᨨ  ⼄盐 ᆠ�矄 b 㡰  ᆠ ᆠ盐  矄矄� �㜠 ᨨ盐�    � 矄盐ᨨ  矄鼀�ᆠᨨ 盐ᆠᨨ졠⧤�矄 ᨨ犨  ᨨ � �  ᆠ�矄  꾀⧤ � 矄盐ᨨ ᨨ矄 ᨨ鼀� 泐ᆠ盐 ᨨ ᨨ犨 ᨨ盐� � 꾀⧤矄鼀�ᆠᨨ 盐ᆠᨨ 矄矄 � 矄盐ᨨ

WWW.JEEBOOKS.IN

PS-217

Current Electricity

C

҈�

ᔼ 矄�矄� �K矄鼀 � �ᆠ盐  ᨨ犨矄 ᨨ盐�  p㜠n 盐 ᆠ�ᨨ  �ᨨ  ᔼ ᆠ矄ᨨ 鼀 ᆠ盐  ᨨ犨� �犨�泐㜠泐 �� ᆠ盐矄 鼀ᆠᨨ鼀矄矄盐ᆠᨨ 盐ᆠᨨ⧤ b 㡰ᔼ  ᔴᆠ�ᆠ盐� �矄ᆠ �� �ᆠ盐  I 㦨 Iet/RC C҈

ᔼ ��ᆠ盐 I㦨

҈黨



C

V  R 



꾀矄V   R ᨨᨨ  ᆠᆠ�ᨨ矄  矄鼀 矄ᨨ� �� �矄ᆠ �� � ᆠ盐 犨�矄鼀盐 ᨨ 㜠 ᨨ 꾀矄ᨨq 㦨 qet/RC

҈䰘

\�҈㦨

M

e 졔 t/RC 㦨Þ t㦨RCᨨ�e\tµC

\

t҈ C҈ ҈ = 㦨 = �  t  C

V 㦨�҈R 졔

q q    㦨qet/RC   ᨨ t҈ 㦨�t

 ᆠᆠᆠ�ᨨC҈ᨨ矄矄矄�奠ᨨ �矄� ��ᆠ �矄ᨨᨨ  

Cᨨ矄矄矄�奠ᨨ �矄� ��ᆠ � 꾀®s �鼀�ᆠ矄��矄矄 ᨨ  鼀  矄�ᨨ ᨨ 矄ᨨ� 矄�l㦨l ҈졔µt㡰 ®q 和鼀 �� �矄矄 ᨨ  �泐ᆠᨨ 矄�ᨨ  ᔴ®p, q ᔼ ᆠ 矄ᆠ 鼀�矄矄 ᨨ  �泐ᆠᨨ 矄�ᨨ �ᆠ�ᆠ �泐 � ᨨ��  �泐  ��ᨨ  ᨨ鼀 ᨨᨨ 泐 ®q, r 쟼ᆠ�ᆠ 盐矄 �矄 矄 ᨨ  鼀� � ᨨ    盐矄 鼀� 犨 �ᆠ  �

盐   矄ᨨ   � � ᆠᨨ ᆠ盐  ෌� Q㦨Q᲼҈eat桌 Q㦨鼀 �鼀盐鼀ᆠ �

Q + �R C

T

B

ᨨ

a㦨

 ��㡰

쟼�鼀� � �� ᨨ鼀⼄盐�ᨨ  �㡰  ��㡰犨� V㦨�҈R졔 ᨨ

�҈㦨

Q ᨨ C

�҈R㦨V

҈ æ Q ö çV ÷ ᨨ R è C ø

Q C

dQ ҈ æ Q ö = çè V ÷ dt R Cø Q t dt dQ ò æ Q ö = ò R çè V ÷ C ø

dQ dt ᨨ = Q ö  R æ çè V ÷ Cø CV ᨨQ㦨 ҈et⏌RC㡰  ù dQ d é CV ҈ - e-t ⏌RC ú = ê 㡰 �҈㦨 dt ë  dt û V -t ⏌ RC CV  e = ´ ´ e -t ⏌  RC  = R   RC ᨨ

(

҈ ҈ = t c C  q

ᨨ犨 鼀 �鼀盐鼀ᆠ � Q㦨C᲼V桌犨 V㦨鼀 ᨨ � �  ᆠᆠᨨ矄矄C

é

ù V ´ R ú ë R҈ + R û

)

ᨨ鼀 ⼄盐�ᨨ  �㡰

= C ê

V+

V -t ⏌RC e  \ ᔴ盐  ᨨ盐� AB R

 ç

V + �҈R �㦨 = R

\ a =

V -t ⏌  RC e V  - e -t ⏌  RC �㦨��҈㦨 R R V V -t ⏌  RC V e Þ �㦨 ᨨ �㦨 矄t® ¥ R R R

æ

ö V ÷ �矄  矄 泐矄 ᆠ盐  ᨨ盐�  R è R҈ + R ø é R҈R ù 꾀  t c = C Req  = C ê ú ë R҈ + R û (Q R҈  R � ᆠᨨ鼀� �ᨨ )

҈

R

dQ dt

㡰 꾀泐� �⧤ �    ᨨᨨ MNABM V㦨 ��҈㡰R 졔�R ᨨ V 㦨�R�҈R  �㡰 和�鼀�泐 泐� � ⧤ �  ᨨᨨ MNSTM

␔  q㦨

҈

ᨨ  ᨨ矄 ᨨ   �├  ᨨ � B A ��  泐 矄 ᨨ盐   ᆠᨨ

ᆠ R ᆠᨨ矄矄A  B졠盐盐ᆠ ├ ᆠᨨ矄矄  鼀� 矄A  C ᨨB  C V 꾀ᆠᆠᨨ � �ᨨ ⼄盐矄�ᨨ ᆠᆠ�ᨨ �矄� ��泐 盐 ᆠ �     矄犨�ᆠ s�矄ᆠᨨ矄 �鼀矄t㦨  泐�鼀tᆠ �ᨨ ᆠᆠ�ᨨ R A �҈ S C Qᆠ盐 矄矄矄 ᨨ犨 N � �㜠�҈㦨� �  ��和� ᆠᆠ �Q 犨�� ᆠ矄 Q+ 犨� �鼀 ἘtἘ R C V

R + R ҈ = ҈ tc CR҈R

҈

ᨨ� 泐ᨨ 鼀Ἐ矄犨 ᆠ�ᆠ盐� ��鼀�矄矄矄 ᨨ犨 ᨨ犨 꾀 鼀鼀�矄ᨨ犨矄�矄 ᆠ� ᨨ鼀犨 �ᆠ �矄ᆠᨨ

ᆠ ᨨ 犨�  矄�矄 ᆠ ᨨ鼀�矄 �� 矄�矄 ᆠ � ᨨ鼀犨 �ᆠ �矄ᆠᨨ

ᆠ � 矄�矄犨�   矄�矄 ᆠ 꾀鼀鼀

ᨨ鼀





҈ W

G



�ᔴᨨ�

V+

҈ W

҈W

␔ᆠ   犨 ᆠ�ᆠ盐�矄 ᨨᨨ犨矄 �矄�矄 ᆠ 犨  矄ᨨ  � � E

쟼⼄盐�  矄�矄 ᆠ 犨

G  D

 ´  =  W RGD 㦨  +  RGE REB =  RGD RDB

G

æ ᆠᨨ ��ᨨ ᨨ  ᆠ ö ç ÷ è 犨 矄ᨨ � � ø

҈W

W I⏌

I⏌

҈W

M W V W

D

B

҈W

҈

WWW.JEEBOOKS.IN

EBD_8341 PS-218

Physics

E⼄盐� 矄�矄 ᆠᆠᨨ矄矄G  B RGB 㦨

҈ ҈  ´  V = ҈� W \ ᔴ盐 I㦨 = =  +  RGB ҈� ҈�

ᔴ盐 

ᔼ  盐   �� 矄 � ᨨ 犨ᨨ ⼄盐 矄  㝐 

 ᆠ ᨨ � �  ᆠ ᆠᨨ矄矄   ᨨ鼀 ෌㦨ᔼ =  �m 㦨C E

�

 = ҈� 꾀 ҈ +   Q P  d �矄 矄鼀 \  I҈ =  I Þ I  =   I҈ + I  = I҈ + I҈ = ҈� \ I҈ = ´ ҈� = 黨 A �

ᆠ盐   ᨨ盐�  泐㦨

҈   I = ´   = ´ 㦨䰘 ҈�   

෌�  ᆠᨨ矄矄 W矄�矄 ᆠ㦨V \Pdᆠᨨ矄矄 W矄�矄 ᆠ㦨V㦨V 꾀矄   ᨨ鼀 �矄 �     犨�     W 矄�矄 ᆠ  � ᆠᨨ鼀�   矄�矄 ᆠ

R ҈=W

RἘ =

E҈=

G �

R 㦨W 㦨E 

D E 㦨 

�

A

�҈ �+�҈

 R' 㦨 W矄  ᨨ � �  ᆠᨨ   V �矄 ⼄盐泐 矄  犨  W W矄�矄 ᆠ

�҈ B F R㦨W �

R㦨W

�

\  =

C

�㦨 -

R ἘἘ =

҈ A �

I=

㦨V㦨IR'' =

 ᆠᆠ盐 � R㦨�҈졔�㦨҈䰘㦨҈�A 꾀ᆠᨨ矄矄   ᆠᆠ�ᨨ ᨨ � �  ᆠ VE맔㦨VG\ VEVG 㦨V

㦨 

꾀泐� �⧤�ᆠ ᨨ Ἐ矄 �矄犨盐 ᆠ�ᨨ  M Pᆠ盐 �҈㦨 A  �㦨 ҈꾀矄ᆠ�泐

鼀  A



҈ CV  

҈ 맔�맔҈맔 㡰 㦨 ҈맔҈�   ҈A W 4V W M �҈ �W

V  V A \ ᨨ鼀 � � = = R W 

㦨ᨨ � �  ᆠᆠᨨ矄矄  W 矄�矄 ᆠ

æ ҈ö �

�҈㦨҈� ç - ÷ 㦨҈䰘A è ø

쟼 �泐矄ᨨ � ᆠᆠ�ᨨ㦨

R  ´ ҈ = = W  + R 㡰  + ҈㡰

\ ᨨ矄�矄 ᆠ�  ᆠ�盐�㦨졔㦨W \ᔴ盐 �  ᆠ�ᆠ盐�

和盐矄�盐� � �矄盐� ⼄ �㡰犨�

\

䰘





q q - + ҈ =  Þ q㦨҈�ҘC   m F

҈ ҈ CV  = 맔맔҈맔맔㦨맔҈  

矄�矄 ᆠᨨ W  W� 

mF

҈mF

mF

N

҈mF

mF

҈mF

҈mF ҈mF

C mF ҈W ҈W P � W O W W ҈A

´ = ҈ W Req㡰AB 㦨 +

 ´  = �V 

ᔼ 矄�    泐 ᆠ盐  ᨨ犨矄 ᨨ鼀   ᨨ矄�� 鼀�  ᨨ   ��鼀� ᨨ  泐 盐� � ᆠ �� �   ᨨ � �  ᆠ 犨    犨ᨨ 鼀� 矄 ᨨ    泐 V㦨E 졔Ir 㦨졔�맔҈㦨� V 꾀泐� � ⧤�ᆠ  ᨨ Ἐ矄 犨 KVL �  ᨨᨨ AQBRC

҈mF

W

҈W

҈W W

҈

mF

꾀 矄 泐矄矄 ᨨᆠ盐  ᨨ犨矄  ᨨ盐�  ᆠᆠ�ᨨ 㝐ᨨ� � ᨨᨨᨨ �MNO ᨨP \ VM �맔�҈҈맔I҈맔�㦨VP \ VM VP㦨�҈졔�㦨맔졔맔҈㦨V \ V㦨맔졔맔҈㦨V 쟼 �泐矄ᨨ  �    ᆠᆠ�ᨨ 㦨

 R Þ R㦨҈W  + R 㡰

�  矄�矄 ᆠ ᨨ    ᨨ�鼀  㦨 ҈W␔     ᨨ鼀�矄ᆠᨨ

ᆠ ᆠᨨ矄矄 W矄�矄 ᆠ �ᆠᨨ鼀�  矄�矄 ᆠ

꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 �  ᨨᨨ ABFGA  �҈졔�㡰㦨  �㡰 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 �  ᨨᨨ BCDEFB �맔졔�졔 �졔�҈㡰㦨  ��㡰 盐� � 盐ᨨ  �҈졔�㡰㦨� ⼄ ��㡰 ��졔�졔㦨 \

 R  R㦨矄�矄 ᆠᨨ ᨨ鼀㡰  + R 㡰

Q 졔q 㜠q

҈ mF

B

졔q 㜠q

A

҈ D

\

҈mF

R C

E

ᨨ � �  ᆠ 犨  AB V㦨

q ҈� = �V VAB㡰 㦨 C 

\ ᨨ � �  ᆠ 犨  BC VBC㦨҈�㦨䰘�V

WWW.JEEBOOKS.IN

PS-219

Moving Charges and Magnetism

Moving Charges and Magnetism

18

Topic-1 : Motion of Charged Particle in Magnetic Field ҈

�

r

m㦨鼀矄矄ᨨ ᨨᨨ

q㦨ᆠ �ᨨ ᨨᨨ

B㦨鼀� �ᆠ �  �  �矄 ᆠ   �  ᨨ  ᨨ盐�ᨨ  p㦨T v ᆠᨨ矄q㡰 v㦨 ᨨᆠ�泐ᨨ ᨨᨨ 㡰 \ � ᨨ ��ᨨ  l = ҈ ´ v ᆠᨨ矄 q㡰T

ᆠ㡰 E =  ˆ ⏌ᆠ鼀 =  ´ ҈ ⏌鼀

r V =  ´ ҈ �ˆ E E =  

y x

⏌ᆠ鼀 =  ´ ҈ ⏌鼀 e V $ V =  ´ ҈ �

pm qB pmv  ´ ҈ ´ ҈䰘 ´ ҈ -䰘 ´  ´ ҈� Þl= = qB ҈ ´ ҈ -҈黨 ´  Þ l =  鼀

E = VB

E  ´ ҈ = = � ´ ҈- T V  ´ ҈  ᆠ鼀� �ᆠ � B㦨�맔҈ ᨨ �졔z �ᆠ�ᨨ  ᆠ㡰 ᔼ 盐 � ᨨ鼀鼀� �ᆠ � �ᆠ鼀ᨨ矄�  ᆠ�ᆠ盐  �   �盐矄ᨨ  ᆠ�ᆠ盐 �矄'r'�ᆠ犨� ᨨ �   矄ᆠ  \ B=



鼀  �㡰 ⼄   �矄 矄��  �   

⼄쟼㦨⼄ 쟼 쟼㦨 Þ  =  ��㡰  ᨨ鼀⼄盐�ᨨ  �㡰  ��㡰

é mv  ù mv = qvB ú êQ qB r ë û  ᆠ鼀� �鼀盐鼀盐ᨨ v ᨨ犨 �ᆠ  �ᆠ犨� ᨨ �   矄ᆠ  qB d v= m 㡰 ᲼෌�  q = ҈mC = ҈ ´ ҈- C錐 r V = �ˆ +  ˆ + kˆ㡰 鼀⏌矄  r B = ��ˆ +  ˆ - kˆ㡰 맔҈  桌

䰘

r r r F = q V ´ B㡰 = ҈ - ´ ҈ -

= -�ˆ +  ˆ - 黨kˆ㡰 ´ ҈-黨

�  - r  \ F = -�ˆ +  ˆ - 黨kˆ㡰

pm qB

pm \ �ᆠ  = V ᆠᨨ矄 q㡰 qB p æ ҈䰘 ´҈-䰘 � =  ´ ҈ ᆠᨨ矄  ° 㡰 ç   çè ҈黨 ´҈-҈黨

´ ( �) ´ � ´҈  ҈

b㡰 꾀矄鼀㦨⼄Þ  =

҈ ᲼꾀矄  鼀 = ⧤쟼  Þ 鼀   = 鼀 ⧤쟼



鼀 = ⼄

鼀⧤쟼 ⼄

Þ 鼀 = 鼀 ⧤쟼桌 ᨨ ᨨᨨ  ᆠᨨ    a㜠�ᆠ 鼀㦨鼀 鼀>>鼀 꾀矄ᨨ㦨⼄ ⼄㦨⼄ \ 꾀矄⧤쟼ᨨ  �ᆠ矄�矄矄鼀   鼀 ⼄ \㦨> a

kˆ 

�ˆ ˆ  

㡰 �ᆠ  = v ᆠᨨ矄 q㡰T   T =

҈黨

⼄ ҈ ´ ҈ = 쟼 \鼀㦨맔҈├� 鼀=

r=



㡰 꾀矄 �ᆠ�矄 鼀ᨨ� �ᨨ �ᆠ�ᆠ盐

\ =

d



pm qB

Þ l = ҈ ´ v ᆠᨨ矄 ° ´

z

r B 鼀盐矄� 졔z �矄 r r r qE + qV ´ B = 



ᆠ㡰 �鼀 �ᨨ  ᨨ  ᨨ  ᨨ盐�ᨨ  ᨨ  ᨨᨨ  T =



㡰  �盐矄ᨨ  ᆠ�ᆠ盐 犨�  =

鼀 ⼄

鼀⧤쟼 Q  = 鼀 = 鼀⧤쟼 㡰 ⼄ Q⧤쟼㦨⼄D Þ =

鼀⼄D 鼀 Þµ ⼄ ⼄  ҈ \ = a 

\ = ö ÷÷ 㦨ᆠ鼀 ø

WWW.JEEBOOKS.IN

EBD_8341 PS-220

黨

Physics

㡰  �盐矄ᨨ    㡰�矄�� 泐  =

=  =

(

鼀├  鼀 

鼀 ⼄

Q  = 鼀 = 鼀├

҈

)

꾀  犨 ├ ᨨ犨 Þ R 㦨

Q ├ = 㡰  ´ 黨҈ ´ ҈ -҈

=

鼀   = 

=

黨҈ ´ ҈ -҈  ҈ = ´ ҈ - -҈  ҈

鼀  ⼄

=  㡰



⏌









⼄ é - � -  ù ê ú 鼀 ë  û  �矄 ᨨ�ᨨ  �矄 ᨨ ��  �     ᨨ ᨨ盐 ᆠ ᨨ�ᆠ矄 b㡰 꾀矄犨├ ᨨ犨 �盐矄ᨨ ᆠ�ᆠ盐 � 鼀� �ᆠ � =

҈҈

=

⧤鼀 ⼄

ᨨ ᆠᨨ   = ᨨ ᨨᨨ   = ᨨa�ᆠ a =

҈

҈

⧤鼀 

 �㡰



⧤鼀   ⧤鼀 ⼄a 

 ��㡰 =

⧤鼀 

=

 \ 㦨a Q 鼀鼀㡰 b㡰  ᨨᆠ �矄  ᨨ  �ᆠ�ᨨ

ᨨ ᆠ盐 � 鼀� �ᆠ �  r  ᆠ = ⼄  ´ 㡰 ᔼ 꾀ᆠᆠᨨ � � ᨨ 鼀� �Ἐ矄     盐

犨    �ᆠ�ᨨ  ᨨ  鼀ᨨ�ᨨ  ᨨ ᆠ ��矄 ᨨ犨 矄   犨� b㡰 턼  㦨⼄쟼  㦨⼄ \쟼㦨 꾀 ෌盐矄矄Ἐ矄犨 � 쟼ᆠᨨ矄�ᆠ矄 쟼 㦨

s 㦨  Þ s 㦨 e   e σ҈㦨  σ  쟼㦨

R a d

dqB mv

쟼 ҈ = = ҈ 犨 ⏌ 鼀   ҈ ҈ 㡰 矄   ᆠᨨ ᨨ鼀 ᨨ  B   v �    ᨨ鼀盐 ur r ur F = q v ´ B㡰  ᨨ �   � 矄  ᨨ盐矄 �ᆠ�ᨨ  ᨨ  ᨨᆠ x㦨a x㦨a ᔼ  ��ᨨ axa ᨨᆠ鼀盐矄�   �ᆠ�ᨨ  �ˆ ´ ˆ �.e. 졔z㜠 �ᆠ�ᨨ  矄ᨨ �ᆠ泐盐犨 꾀  �    ��ᨨ

axa� z㜠 �ᆠ�ᨨ �ᆠ泐 ᨨ犨 犨  ҈䰘 b㡰 㝐� �ᆠ ᨨᆠ ᨨ    ᆠ �  �ᆠ ᨨ矄 ᨨ ᆠ  � �矄 矄 \ u㦨v

 ᨨᆠ ᆠ� � ᨨ

X B y ᆠᨨ  犨�   �ᆠ盐 ᨨ   �ᆠ�ᨨ  ᨨ ᨨᆠ�泐� e u x   ᆠᨨ  鼀� 矄 �

  鼀� �ᆠ �  和ᨨ  ᆠᨨ  犨� ᨨᨨ犨   矄�� ᨨ犨  ᆠᆠᨨ ᆠᨨ鼀矄ᨨ盐 犨� 矄  v㦨u y r ҈ b㡰 ␔   E 㦨   ᨨ  ᆠ � �ᆠ泐ᨨ P犨� �   ᆠᨨ�ᨨ  㡰  ᆠ㡰� ᆠᨨᆠ  ᨨᆠ�泐 P�矄 �   X㜠 �ᆠ�ᨨ  �� 㡰 r  v = k�$ 꾀  ᨨ矄��泐ᆠ � �ᆠ�矄  ᆠ �   x y ᨨ犨 y �ᆠ�ᨨ    �矄 ᨨ 㜠ᆠ�ᆠ盐 ur r ur ᨨ犨 F = q v ´ B㡰 ur Þ F = q ᲼k�$ ´ ckˆ + a�$㡰桌  ᨨᨨ�ᨨ  㡰 Þ=

 

㡰

a

q éQ qV = ҈ mv  ù ê ú  û mV ë ҈� ᆠ㡰 和� ᆠ �ᆠ �矄 鼀ᨨ� � 盐  ᆠ 和ᨨ ⼄ 쟼 = ⼄

 = 䰘� ´ ҈ 졠N和㡰 꾀矄矄盐鼀� � �ᆠ 矄 ᨨ鼀  㡰

=

mv   㦨 qvB R

矄�  a 㦨 Bd

-

҈

mv qB

\ 矄�  a =

�㡰

҈ ´ ҈ -҈黨 ҈ ´ ҈-

㡰 ᨨ鼀 ��盐 矄�  a 㦨 d⏌R

s e

⧤鼀  

 ���㡰

ˆ $ ´ $� 桌 㦨kcq - $ 㡰 㦨 q ᲼kc�$ ´ kˆ + ka�



 Ä

҈黨

ur

和� ᆠ �  ᨨ�ᨨ  㡰 ᆠ�ᆠ �  �矄 矄ᨨ 矄  E = a�$   ᨨ�犨�矄ᨨ  ᨨᆠ�  졔X �ᆠ�ᨨ  

矄盐 ᨨ  犨ᨨ ᨨᆠ矄 犨� ᨨ 㜠ᆠ�ᆠ盐  졠 泐ᨨ�ᨨ  㡰 �矄 ᨨ  ᨨ ᨨ��ᆠ b㡰 ␔    ᆠ �  �ᆠ �矄 鼀ᨨ� � �   盐 � ᨨ鼀 鼀� �ᆠ �  ᨨ鼀 ᨨ�矄鼀ᨨ�ᨨ

qvB㦨

q x=a

mv  R X v

x=b

WWW.JEEBOOKS.IN

PS-221

Moving Charges and Magnetism ␔�  ᨨ  鼀� �ᆠ � ��ᨨ  ba㡰R錐犨 ἘRἘ�矄 �矄  �盐矄 ᨨ ᆠ盐盐 � 矄�  鼀� �ᆠ � 

mv b - a 㡰 qB ³ ba㡰 Þ v鼀� 㦨 qB m  b㡰 ␔    ᆠ �  �ᆠ �矄 鼀ᨨ� � ᨨ鼀 ᨨ   鼀� �ᆠ �     ᨨᆠ ᆠ矄 ᨨ  � 犨 �ᆠ   矄 矄  ᆠ � ᨨᆠ 鼀ᨨ矄 �ᆠ� ᆠ�ᆠ盐鼀ᨨ�ᨨ  \ R㦨



㡰 㝐� �ᆠ �   ᆠ  盐 ᨨᆠ盐 � ᆠAB m  I҈ q B҈㦨 犨 矄㡰 p r C

I

 p㜠q q

A



mv mv  Þ r㦨 \ F㦨qvB㦨 qB r ᔼ q B矄鼀 ᨨᨨ   rµmv

B

I҈ I

B

E

㝐� �ᆠ �     ᆠ  盐 ᨨ ᆠ盐  �  ᆠ ACB

B

和� ᆠrA>rB Þ ҈



mAvA  mBvB

r

ᆠ㡰 ෌�  ᆠ�ᆠ �  ᨨ � 졔x �ᆠ�ᨨ  E = E �ˆ   r 鼀� �ᆠ � ᨨ �졔z �ᆠ�ᨨ  B = Bkˆ ᨨᆠ�泐 ᨨ    �ᨨ �矄  �ᆠ 犨�  ᨨ � �ᆠ�ᨨ

r 鼀�   泐 qE r ᨨᨨᆠ�泐 v = AqE�ˆ 犨  A �矄  ᨨ矄�� ᆠᨨ 矄   A E   B  ᨨ矄�� ᆠᨨ 矄 矄 ᔴ � ᨨ �ᨨ 矄 q㡰 鼀泐 ᨨ矄�� ᨨ �� r r r 㝐� �ᆠ ᨨᆠ F = q v ´ B 㡰 r \ F = q᲼ AqE�ˆ㡰 ´ Bkˆ㡰桌 㦨q AEB �ˆ ´ kˆ 㡰 㦨q AEB - ˆ 㡰 㦨 ᠀q㡰AFBᨨ � ��y㜠 �ᆠ�ᨨ  꾀矄 鼀� �ᆠ ᨨᆠ�矄 ᨨ � ��y㜠 �矄  ᆠ�ᨨ 矄 犨   ᨨ矄��ᨨ �� 犨�  ᆠ ᨨ犨 矄 �� y㜠 �矄 ᆠ㡰  �盐 鼀ᨨ鼀 盐鼀 ᨨ  �ᆠ L㦨mvr㦨mrw犨 w㦨pn ᲼Qv㦨rw桌

q w wq 錐  盐 �㦨 㦨q 맔n㦨 t p p wq qr  w ´ pr  Þ M㦨 㝐� �ᆠ鼀ᨨ鼀 M㦨�A㦨 p 

\ ⼄盐 ᆠ泐n㦨

\ 

Ҙ I  ( p - q) ᨨ犨 犨 矄㡰 p r \ 鼀� �ᆠ �    ᆠ  m  I҈ q m  I  p - q㡰 B㦨  p r p p r E E EA é lù QR =r ú = = 꾀矄ᨨI҈㦨 R rl ⏌ A rr q ëê Aû B㦨

A

M q wqr  = = L  mr  w  m

r r 㡰  � ᨨ鼀 ᆠ�ᆠ �  E    鼀� �ᆠ �  B    ᨨᆠ  ᨨ  FE㦨qE ᨨᆠ 盐 ᨨᆠ�ᆠ � 㡰 FB㦨evB矄�  q 㦨qvB矄� 㦨 ᨨᆠ 盐 ᨨ鼀� �ᆠ � 㡰 E 졔q

B 和� ᆠ ᨨᆠ 盐 ᨨ鼀� �ᆠ � �矄 ᨨ 和ᨨ ᨨᆠ 盐 ᨨ ᆠ�ᆠ �  犨� 鼀├   ᆠ �  �ᆠ ᆠᆠ ᨨ ᆠᨨ�矄 � 矄�� � 

҈

 I㦨

҈

E E EA = = R rl  ⏌ A rr p - q㡰

m é EA q EA p - q㡰 ù ´ ´ ê ú= p ë r r q r rr p - q㡰 r û � ᆠ㡰 꾀   � �   鼀� �ᆠ �   鼀� �ᆠ ᨨᆠ ᆠ矄 ᨨ    ᆠ �  �ᆠ 犨 �ᆠ  鼀ᨨ矄   ᆠ � �ᆠ� ᆠ�ᆠ盐 \ B㦨

mv m K mv  㦨qvB Þ R㦨 ᨨ R = qB qB R KqB⼄盐 \ Rµm \

m҈ R҈ = m R   盐 �    ᔴ �矄 ᨨ ᆠ �矄矄 �ᆠ 盐ᨨ  꾀ᆠᆠᨨ � �ᨨ 鼀� �Ἐ矄   盐  ᨨᆠᨨ ᆠᨨ 矄 ��ᆠ �㡰犨�ᨨ犨 矄�� �.e.ᆠ├D 꾀矄ᨨ泐 矄鼀盐犨 �    ᨨᆠᨨ ᨨᨨ  a㜠�ᆠ�.e.졔 㡰泐ᆠ � �ᆠ�矄ᨨ犨 矄 ᨨ犨 矄� ᆠ 鼀� �ᆠ ᨨᆠ犨�  矄 ᆠ � ᨨᆠ  m \ mv = qvB ᨨ µ q r ҈  ᨨᨨᨨ rµ = ҈ 錐 ᨨa㜠�ᆠ r µ =  ҈  �.e. (r㡰a> r㡰p \ a㜠�ᆠ犨�├ B 䰘 矄 ⧤� �ᆠ �泐⧤ᨨᨨ 㦨⧤ᆠᨨ 㦨⧤  ᆠ



mv  = qvB r

Þ

r㦨

 mK mv Þ r㦨 qB qB

᲼Qmv㦨P㦨 mk 桌 \ rµ m ᲼ ᨨᆠᨨ 矄  qK  B桌 \ rµ m 和� ᆠ 鼀矄矄 ᨨ ᨨᨨ  > 鼀矄矄 ᨨ ᆠᨨ    ᨨ  �盐矄 ᨨ ᨨᨨ 犨�鼀ᨨ

WWW.JEEBOOKS.IN

EBD_8341 PS-222



Physics

矄

  ᨨ  �ᆠ�矄  ᆠ�ᆠ犨   �  矄 ᨨ鼀 ᨨ   鼀� �ᆠ �   ᨨᆠ�泐 ᆠᨨ鼀ᨨ   v  犨�  矄ᨨ 矄��  鼀ᨨ� �  ᆠ � �ᆠ�   ᆠ�ᆠ



B v v㦨v矄� q

q

)



v҈㦨v ᆠᨨ矄q

ᆠ㡰ᔴ  �� 鼀ᨨ鼀 盐鼀㦨  p

黨

 ᨨᆠ�泐ᆠᨨ鼀ᨨ   v҈ 犨�  矄ᨨ 矄� �  鼀ᨨ� �   ᆠ �  �ᆠ �  ᨨ� ᨨ  �ᆠ�ᨨ   ᨨ   ᆠ � �ᆠ犨��  �ᆠ  T盐

 鼀� �ᆠ ᨨᆠ ᆠ� � ᨨ   ᆠ �  �ᆠ �矄 �   �ᆠ�ᨨ   �ᆠ盐 ᨨ   �ᆠ�ᨨ  ᨨ  ᨨᆠ�泐   ᆠ � ᆠ

ᨨ ᆠ  �   矄  ᨨ   ᆠ �  �ᆠ

æ ҈ ö 鼀 ÷ ᨨ矄 ᨨᆠ  � è  ø 꾀矄犨ᨨ├ ᨨ 泐 �矄 ᨨᆠ�矄 ᨨ矄ᨨ  �泐ᨨ 鼀ᨨ� � ᆠ  �  �ᆠ矄 鼀� 矄 盐 ᆠ  �   b㡰 㡰 ᨨ ᆠ �졔턼ᨨ盐 ��ᨨ ҈

 ᨨ ├� �ᆠ �泐 ç =

 ù p é mv  = QB  ê  �盐矄r = R ú = QvB Þ ë  û R R ⏌ 㡰 p \ B = QR p

 ᨨ ᨨB³  �ᆠ犨�㜠 ��ᨨ ҈ QR p ҈QR mv  æ p ö = Qv ç ÷ r è ҈QR ø

mv mv  = qvB \ r = \ rµm qB r �.e. �矄 ᆠ �矄 �ᆠ泐ᨨᨨ�ᨨ  ᨨ 鼀矄矄 ҈ bᆠ㡰 㝐� �ᆠ ᨨᆠᆠ� �ᨨ ᆠ盐 ᆠ泐� �犨�ᆠ �

盐 � ᨨ鼀鼀� �ᆠ �  r r r F = I l ´ B 㡰 r  l 㦨 �矄ᆠ鼀 ᨨ  犨�㦨 L졔R㡰 xˆ r r \ F =  I L + R 㡰 xˆ ´ B 㡰 r ᔼ  B = Bxˆ  

r F =  I L + R㡰 xˆ ´ xˆ 㡰 B㦨 㡰 盐 

泐 㝐

㡰␔   B =

\ r =

҈ R 

盐矄ἘᔴἘ�矄 ᨨ  ᆠ ᨨ ᆠ�ᆠ盐 ᨨ  �盐矄

҈R 

Ӹ



 









r ᔼ  B = Byˆ  

r F =  I L + R 㡰 xˆ ´ yˆ 㡰 B 㦨IB L졔R㡰 zˆ ᨨ Fµ L졔R㡰 r ᔼ  B = Bzˆ  

r F =  I L + R 㡰 xˆ ´ zˆ㡰 B =  IB L + R 㡰 yˆ ᨨ Fµ L졔R㡰 ᆠ㡰 꾀ᆠᆠᨨ � � ᨨ 鼀� �矄     盐 鼀� �ᆠ � 矄 ᨨ盐  �     �ᆠ�ᨨ  vy  = ᨨ鼀 ��盐  q = vx   泐





�R 





R ⏌ 



҈ 졔턼

\ q = 

꾀矄ᨨ CP = CO + OP 



æ � R ö æ R ö = ç ÷ ÷ +ç è  ø è  ø



҈ R 

盐矄  �ᆠ 犨�  ��ᨨ    ᨨ盐�   ᨨ�  ҈ ᨨ 㜠 �矄 \ᔴ㦨

p 

맔 맔 맔 맔 턼㝐맔졔 맔 맔

q





맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 盐� = 盐 = �ˆ 맔 맔 맔 맔

盐 㦨

맔 맔 泐 㦨 맔 q 맔 맔  = 맔   맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 맔 맔 맔 맔 맔

ᆠ 矄 맔�鼀 =  �盐矄  �盐矄 㝐 ù é p  ´҈ ´ ҈- =  êQ  �盐矄 = 턼 úû  M ´  ⏌ QB ë

꾀 �ᨨ 泐 �ᆠ =

\ B =

�pM Q

WWW.JEEBOOKS.IN

PS-223

Moving Charges and Magnetism 

ᆠ 㡰 ᔼ  q 㦨 º   ᆠ � �ᆠ �矄 ᨨᆠ  ᨨ � x㜠 r  �矄 盐ᨨ鼀� �ᆠ �  B   ᆠ �  �ᆠ 犨�  ᨨ鼀ᨨ� ᆠ�ᆠ盐 � y㜠 z  盐 盐 ᨨ ᨨᆠᨨ



y

r ᆠ�ᆠ �  E  �ᆠ犨� 鼀ᨨ�  �ᆠ 犨� � ᆠ矄� � �ᆠ  ᆠ ᨨ�ᨨ 矄 꾀㡰   㡰  犨ᨨ �

x

ᔼ  q 㦨 ҈º 犨 ᆠ  矄ᨨ ᨨᆠ�泐� ᨨ 犨ᨨ ᆠ �盐 ᆠᨨ鼀ᨨ  矄졠 ᨨ �x㜠 �矄 vᆠᨨ矄҈º㡰 ᨨ ᨨ �y㜠  �矄 v矄� ҈º㡰盐ᨨvᆠᨨ矄҈º �ᆠ犨�鼀ᨨ�

ᆠ�ᆠ盐     盐 ᨨ v 矄�  ҈º 盐矄   ᨨᆠ 盐 ᨨ ᆠ�ᆠ �  �ᆠ犨�盐 �ᨨ �ᆠ鼀ᨨ�ᨨ 犨� �矄 �ᆠ  � ᆠ矄� �



⼄l 鼀 Þ= 鼀 ⼄ 掸  �鼀 ├  泐  �ᆠ ᨨ 鼀ᨨ �  ��ᨨ  ᔼᔼ  ᨨᆠᨨ鼀� �ᆠ├� ��ᨨ ᔼ

p鼀 = = 犨 �ᆠ �矄 �   ᨨ v�.e. �鼀 矄 �矄  ⼄ 矄鼀�  ��ᨨ 㜠ᔼᔼ�矄矄鼀 ᨨ 泐ᨨᆠ�泐   ᆠ㡰 ␔    ᆠ �  �ᆠ矄   鼀� �ᆠ �    ᨨᆠᆠ矄ᨨ  �ᆠ犨 �ᆠ 犨�ᆠ矄ᆠ � ᨨᆠ \

B

E

×

×

×

×

×

×

×

×

×

×

×

×2q

×

×

×

×

×

×

×

×

×

2q

q   q q

B

鼀 꾀矄ᨨr㦨 ᨨµ鼀 ⼄ Q鼀鼀\  p鼀   㦨 ᨨ µ鼀 ⼄



 \  㦨  㦨   ᨨ  �  ᆠ 㡰 꾀矄  ^    ��ᨨ ᔼ ��ᨨ ᔼᔼ 盐 � ᨨ鼀矄ᨨ ᨨ  ᆠ � 맔맔맔맔 �ᆠ �  ��ᨨ 㜠ᔼᔼ �矄 ᆠ�ᆠ盐 맔맔맔맔    �盐矄ᨨ  ᆠ�ᆠ盐  맔맔맔맔 鼀 r = 맔맔맔맔 r ⼄ 掸 ᨨ   �ᆠ ᨨ   맔맔맔맔 ��ᨨ ᔼᔼᔼr> l   矄 ᨨ犨

맔맔맔맔 泐 �矄   � 㡰 ⼄l 鼀 > l Þ> 鼀 ⼄

맔맔맔맔 맔맔맔  맔맔맔맔 l



��ᨨ ᔼᔼᔼ

\ rµ

m q

r㦨

mv qB

᲼⧤� �ᆠ �泐�k �B矄鼀桌

҈  ҈ 錐r +µ 錐 r ++ µ ҈ He ҈ O  Þ r + µ ҈錐  r + µ 錐  rO+ + µ  H He

䰘

×

Þ

mk qB

H+

×



mv  r

ᨨ r㦨

r

A

×

l=

qvB㦨

ᔼ  q 㦨 黨º   ᆠ � �矄 鼀ᨨ� � ᨨ �  鼀� �ᆠ � 

 ᨨ  ᨨᆠ 盐ᨨ鼀� �ᆠ � �矄 ᨨ盐  ᨨᆠ 盐ᨨᆠ�ᆠ � 犨�ᆠᆠ �ᆠᨨ �y㜠 �矄 b 㡰

  泐   � ᨨ ᆠᨨ   ᨨᨨ  �    鼀� �ᆠ � 鼀├矄 矄鼀 �犨� 꾀矄矄 ᨨ犨 

 ᨨᨨ  犨� ᆠᨨ鼀ᨨ盐 � � �   矄 q ×

ᨨ鼀 �鼀盐鼀h �h� ��ᨨ ᔼᔼ㦨l

黨

µ

 ᆠ졔  졠졔졔犨�  ᆠ ⼄盐泐 졔犨�  ᆠ  鼀ᨨ矄 矄� ᆠ�矄 �盐矄 �矄矄鼀矄 b 㡰

 �矄 ᨨ ᆠ  � �  ᨨᆠ�泐 ᔼ ᆠ   ᨨ矄矄� 犨 

掸 쟼ᆠ�ᆠ 鼀� �ᆠ � 矄矄 �.e.쟼㦨㦨 和ᨨ   鼀ᨨ  ᨨ 掸 졠犨  ᆠ�ᆠ 鼀� �ᆠ � 矄矄 盐 ᨨᆠ 盐ᨨᆠ�ᆠ � �矄⼄盐 ᨨᨨ矄�ᨨ 鼀� �ᆠ ᨨᆠ�.e. 졔 鼀㦨 �.e.E¹B¹㡰 掸 졠犨  쟼㦨B¹ᨨ�  F㦨qvB矄� q㦨 矄� q 㦨�.e. q 㦨Þv Bᨨ �㜠 㡰 ᨨ   �ᆠ ᨨ 鼀ᨨ �  矄��  � 犨�  ᆠᨨ 矄  ᨨᆠ�泐 r r Fe + FB = 

r r FE = -eE = -e - E xˆ 㡰 = eE xˆ r r éE ù FB = q v ´ B㡰 = -e ê  yˆ ´ B zˆ ú ë B û r FB = -eE xˆ

㡰

S㦨

E xˆ B

FB B = B zˆ



E = E zˆ Ӹ

 ᨨᆠ 盐 ᨨ 鼀� �ᆠ �  㡰  犨� ᨨ�   

ᆠ矄矄泐ᆠ � ᨨᆠ ᨨ ᆠ�ᆠ盐 鼀ᨨ�ᨨ  犨 �ᆠ  犨�

WWW.JEEBOOKS.IN

EBD_8341 PS-224



Physics

� 㜠Ӹ   ᨨᆠ 盐ᨨᆠ�ᆠ �  쟼㡰 쟼犨� ᆠᆠ ᨨᨨ  �  㜠 �ᆠ�ᨨ  盐矄     犨�  �ᆠ 犨�  � ᆠ矄� � �ᆠ 

mv ᨨ鼀⼄ �㡰  ��㡰㦨 qB 

b㡰 �ᆠ犨�鼀ᨨ� 矄�� � ᨨ �㜠 yˆ

㡰 ᨨ犨 鼀� �ᆠ �   矄 盐ᨨ҈҈





- v �ˆ E = - E ˆ

㦨



v �ˆ

X ҈ mv ⏌qB

B = B ˆ

Ӹ

ᔼ   ᆠ�ᆠ �  犨� 泐 ᨨᆠ ᨨ  Ӹ  �矄  泐 ᆠᆠ� �  ᆠ � ᨨ �Ӹ  �矄 꾀 鼀� �ᆠ ᨨᆠ 㦨⼄矄� q 㦨 q㦨҈ ҈

mv mv  㦨qvBÞr㦨  �㡰 qB r ᨨ �  �泐㦨 ├� �ᆠ  �泐



҈  qv mv ᨨ 㦨  ��㡰  m ᨨ鼀⼄ �㡰  ��㡰 qV㦨

r㦨

m qV ´ qB m

ᨨ rµ

ᨨ r㦨

qVm qB

m q

T맔v҈㦨GS Þ

҈ qa ҈  ´ 㦨 㦨  ma qp  ҈ rq   ᆠ � �ᆠ �졠 鼀�ᨨ盐 ᨨ鼀   ��ᨨ  ᨨ  鼀� �ᆠ �   ᨨ�  P     ᨨᆠ�泐 r ᆠᨨ v 鼀├矄  � 犨� x㜠 �矄  �ᆠ盐 ᨨᆠ�ᆠ盐 P� 矄ᆠ矄  ��y㜠 �矄ᨨ� A \

rp

㡰

B

㦨



和ᨨ 犨��ᨨ ᨨ 鼀� �ᆠ � ҈R >R 㦨 

盐矄  ⼄盐�  � ᨨᆠ�泐㦨 -v $� ᨨ鼀 ��盐   ᆠ �  �ᆠ ᆠᨨ矄     ᆠ�ᆠ �

 ��ᨨ  ᨨ 鼀� �ᆠ �  和� ᆠ �鼀�ᨨ  ᨨᆠᨨ鼀ᨨ盐�ᨨ T㦨pm⏌qB

 ᨨ �鼀├ 泐 �ᆠᨨᆠᨨ矄矄 ��ᨨ

T ᨨ 鼀� �ᆠ � �.e.   ᆠ�ᆠ㦨 㦨pm⏌qB  㡰  ᨨᆠ�泐 ᨨ ᆠᨨ 鼀├矄   �  犨� 鼀� �ᆠ � v҈ᆠᨨ鼀ᨨ  ᨨ ᨨᆠ�泐鼀ᨨ ᆠ � �ᆠ �    �ᆠ�ᨨ  ᨨ   鼀� �ᆠ �  犨 矄 v  ᆠᨨ鼀ᨨ   ᨨ ᨨ� �   ᆠ �  �ᆠ �  ᆠ�ᆠ盐 鼀ᨨ�ᨨ   ᨨᨨ   �矄 �ᆠ �ᆠ矄 犨� ��矄犨� 鼀� �鼀盐鼀盐ᨨ � �ᆠ ᨨ  � 

mp

맔 A 맔  M 맔 맔 맔 O 맔 맔 맔 맔 맔 맔 X=

´

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔 맔

맔 맔 vᨨ 맔 P 맔 맔 B = B kˆ 맔 X 맔 맔 맔 맔 맔 맔 X=L

\AO㦨AP㦨R㦨 �盐矄ᨨ ᆠ�ᆠ盐 

mv mv = B qv ÞR㦨  �㡰 qB R L R = L  ��㡰 ᔼ DAPM 㦨矄�  ÞR矄�  㦨L Þ R 

p m 맔vᆠᨨ矄 㦨҈ qB

B㦨

 p mv ᆠᨨ矄 ° q ´ ҈

盐

҈  E mv 㦨E Þ v㦨  m



S

r 㦨҈鼀 v҈㦨v ᆠᨨ矄

pm E ´ ´ ᆠᨨ矄 ° \ B㦨 q ´ ҈ m 㦨

B

v G

v㦨 v 矄� ᨨ

p  ´ ҈ ´ mE ´ ᆠᨨ矄 ° 㦨 q ´ ҈ ҈ ´ ҈-҈黨 ´ ҈

㦨  ´ 黨҈ ´ ҈ -҈ ´  ´ ҈ ´ ҈ ´ ҈ -҈黨 ´

҈ 

҈黨

맔҈맔҈㦨䰘䰘맔҈ ҈-҈黨 ᨨ B㦨䰘䰘맔҈

 꾀 鼀 ᨨ  ᨨᨨ 矄  矄  盐 � ᨨ鼀 鼀� �ᆠ � 㦨

  �q㦨 犨�  ᨨᆠ�泐㦨맔҈�鼀⏌矄 㦨

҈ᨨ� 矄 ᨨ� ᨨ 鼀ᨨ�ᨨ  ᆠ�ᆠ盐鼀ᨨ�ᨨ

ᨨ  鼀 ᨨ ᨨᨨ 矄 矄ᨨ ᨨᨨ 矄 ᨨᨨ犨  �ᆠ  

WWW.JEEBOOKS.IN

PS-225

Moving Charges and Magnetism

mv = qv B r mv ҈䰘 ´ ҈-䰘 ´  ´ ҈� ´  = 㦨҈鼀 r 㦨 qB ҈ ´ ҈-҈黨 ´  ´  �ᆠ ᨨ  � 㦨v҈맔T

B

\

犨 T㦨

p r p r = v v 矄� q

qvB㦨ma Þa㦨

㦨

҈ ´ ҈

-҈黨

qvB m

q ´

´ ´

O

-䰘

V V2= ¾ Ö

´ ´

x

x

x x

x

x x

E

x x

v x x x E

�

´

B㦨

 ⏌  ´ ҈- 

 ´ ҈

=



 ´ ҈

-

´  ´ ҈

㦨҈矄

Topic-2 : Magnetic Field Lines, Biot-Savart’sLaw and Ampere’s Circuital Law

´ ´



V ¾ E´ V 1=Ö

㦨҈҈�鼀⏌矄

x x

 �ᆠ�ᨨ ᨨ  ᨨᆠ 盐ᨨᆠ�ᆠ �  ⼄쟼㡰�矄ᨨᨨ矄� ᨨ鼀� �ᆠ � ⼄ 맔㡰 쟼�矄 � ᨨ矄�� �ᆠ�ᨨ

\맔矄 ᨨ盐 �  ��x㜠 �ᆠ�ᨨ ᨨ矄 ᨨ盐  �  㡰z㜠 �ᆠ�ᨨ  ^ ᨨ� 犨 矄

´

b

G

´ ҈ ´ ҈

҈ ´ ҈

\

F ´ ´

x -

෌� V㦨㦨맔҈鼀⏌矄  㦨鼀鼀 㦨맔҈鼀

´



x x

+ x

p r v 矄� q 㦨prᆠᨨq㦨맔҈맔҈맔ᆠᨨ 㦨鼀 m㦨҈맔҈䰘├�q 㦨҈맔҈҈黨ᔴ B㦨҈

v㦨҈䰘鼀⏌矄 F㦨qv B矄� a ᆠ� �ᨨ犨 矄O泐 鼀� �Ἐ矄     盐㡰 Þ F㦨qvB ᲼Q a㦨黨 桌 \ �ᆠ ᨨ  � 㦨 v ᆠᨨ矄 q ´

�

+ x x

҈



v

´

ÐOEF㦨� Q OEᆠ矄 �盐矄㡰 泐矄泐鼀鼀泐Ð OFE 㦨� \ ÐEOF㦨黨 泐 �ᨨ鼀泐㡰

�矄 �矄   ᆠ � ᆠᆠ�ᨨ



҈҈ v = ҈҈�  Þ r㦨 ҈� = ҈鼀 r ҈ ҈ \쟼 㦨rᆠᨨ矄� 㦨맔 ҈ ´ 㦨҈҈鼀  꾀 �q㦨� ᔼ  鼀� �ᆠ � �矄�  ᨨ盐犨  �ᆠ�ᨨ   �ᆠ  矄�  矄鼀犨泐E  ᆠᆠᨨ � �ᨨ 鼀� �Ἐ矄    盐  �ᆠ犨� 盐  ᨨ犨 矄 ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ

 ᆠᨨ⏌ ᨨ ᆠ�ᆠ矄矄 ᨨ犨 �   ��盐 \ ac㦨

졔q

 �  ᨨ  ᆠ�ᆠ盐  l = pr

q qv = T  pr 㝐� �ᆠ鼀ᨨ鼀 M㦨ᔴ盐 맔꾀 qv  ´ pr   = � ´ pr =  pr ҈ M = q×v×r  ᔴ盐  � =



�

 �盐矄ᨨ ᆠ�ᆠ盐 � 鼀� �ᆠ �  r =

E

mv qB

mv mv  ҈ qv ´ ÞM =  qB B r r �ᆠ�ᨨ  ᨨ  M  �矄 ᨨᨨ矄� ᨨ  B    ᨨ r r - mv  B M = B  泐鼀盐�泐� � ᨨ  盐鼀ᨨ    ᨨ鼀� ᨨ 泐B㡰 \M =

O 졠

� �졠

F

  æ p ö  é p r ù \ �鼀⼄盐� 㦨 T = ç ÷ 㦨 ´ ê  è w ø  ë v úû 

㦨䰘҈맔҈矄 꾀矄 ᆠᨨ  矄矄矄 盐 �  \ ᨨᆠ 盐ᨨᆠ�ᆠ � 㦨 ᨨᆠ 盐ᨨ鼀� �ᆠ �  eE = evB \ B 㦨

E V ⏌d = v v

Vù é êëQ E = d úû



㡰 ෌� IA㦨꾀RA 㦨ᆠ鼀 q A = p -

p p =  

p �p =   m I q 矄� �鼀� �ᆠ �  B = 4pR IB㦨꾀RB㦨ᆠ鼀 q B = p -

WWW.JEEBOOKS.IN

EBD_8341 PS-226

Physics

B A I A q A RB = ´ = BB I B qB RA



p ´   = �p � ´ ´   ´



Ҙ �  矄� a + 矄� b㡰 p r

b㡰 B㦨

r㦨 � -  㦨ᆠ鼀 a㦨b㦨䰘

� ´ 矄� 䰘° 㦨҈�맔҈�

 ᆠ㡰 ᔼ ᆠ盐 � ᆠ 犨� �ᆠ � 犨 矄㡰 㝐� �ᆠ � �졠 盐ᨨ 턼㝐犨� ᨨ �㦨和졔턼 m � m � \鼀� �ᆠ �   =  +   p  p m �  ´ ҈ -䰘 ´ � ᨨ ҈ - =  +  p  ´ ҈ - \  � 㦨  꾀     �ᆠ�ᨨ  ᨨ  鼀� �ᆠ �  �矄  �ᆠ盐 � ᨨ    㡰 \ B㦨 ҈

ᆠ㡰

 

䰘

a

ᔼ a 

㝐� �ᆠ �  盐ᨨ ᨨ  矄�  ᨨ   �ᨨ

m I 矄� ° + 矄� °㡰 B= a p 



m I æ ҈ ҈ ö m I çè + ÷ø =    a  ap ᨨ犨鼀� �ᆠ �  盐ᨨᨨ   �ᨨ ᆠᨨ� m I B = ´   ap 꾀�� 鼀� �ᆠ �  ᆠ ᨨ   �ᨨ 矄 ᆠᨨ� ᨨ �盐 矄

ᨨ B =

m I

҈�m  I  ´ ҈ ´ p

㦨p

= � 

m I p

㦨맔p

ᨨᨨ㦨

\ 黨

m� m  � m  � m   � = = ᆠᨨ�㦨   æ ö  ç ÷ è ø  ҈

 = ᔴ  

ᆠ㡰 㝐� �ᆠ �   ᆠ ᨨ ᨨᨨ ҈ =



(

㡰

鼀  = ᔼp  m ᔼ  =  

(

m I m I m I =  [ 矄� 黨°  矄� �° ] +  +  ᲼矄� � 졔矄� 黨 桌 pR  R  pR mᔼ æ ҈ ö m ᔼ mᔼ æ ҈ ö ҈ + + ҈+ ç ÷ ç ÷ è ø è  p  p  ø

e uuur m ᔼ æ ҈ ö e =  ç p + ÷  p è ø

�

®

®

®

㡰 B = B + B ҈ 

=

( )

µ æ � º ˆ � º ˆ ö  ç k + -k ÷ =  ø d p è d

 \ ҈ =   ҈

)



= ᔼp  = 鼀҈

)

B㦨B҈졔B졔B졔B

=

m ᔼ 

�ᨨ鼀ᨨ鼀 ᨨ ᆠ�ᆠ盐ᨨᨨ�矄鼀㦨ᔼ꾀 鼀҈㦨ᔼ꾀㦨ᔼp { 㦨  �盐矄ᨨ  ᨨᨨ晤 ᔼ 鼀ᨨ鼀  �矄 ᨨ盐  ├� � ᆠ盐  ᆠᨨ 矄 㡰  㜠 ᆠᨨ鼀矄



ᔴᨨ�

㦨Þ㦨 

҈ é ù êëQ a = ҈ = ҈ 鼀 úû

 ap





ᨨᨨ

ÞB=

B = � ´  ´

-䰘

(

m ᔼ  m ᔼ 

= 

)

b㡰 ᨨ� P�矄矄�盐  鼀� 㜠ᨨ� ᨨ  � ᨨ� � �  ᆠ 矄ᨨ  ᆠ�ᆠ盐犨�矄犨 �ᆠ  矄鼀 �� 㡰

r

 鼀� �ᆠ � 矄 B 㡰   盐 ᨨ   ᆠ盐 矄 �    犨�矄� 矄鼀 �ᆠ�ᨨ  㝐� �盐 ᨨ 鼀� �ᆠ �  ᨨ�  P

ì ü m NIR  m NI m  NIR  B㦨  ï ïï 㦨  ⏌  㦨 ⏌  ï ⏌  � R � í æ  R ö ý ïç R + ï ÷   ø þï îï è

WWW.JEEBOOKS.IN

PS-227

Moving Charges and Magnetism ҈� ҈҈

㡰 ᨨ鼀 ��盐

b㡰 ᔴ矄 㡰 ᔼ D졠꾀ᔴᆠᨨ矄 㦨

Ҙ ᔼ Ҙ ᔼ ´ p Qp 㦨฀l㡰 꾀㦨  ´  p =  p  p l ⏌ p Ҙ ᔼ ´ p㡰  㦨 p l � ᔴ矄 b㡰  







㦨  ´

҈

  矄� q㦨

҈ =a  㝐� �ᆠ � Ἐ졠Ἐ 盐ᨨ鼀 꾀 㦨

ᆠᨨ矄q

m I é  ҈ ù m I ҈ - ú= ´  - ҈㡰 ê p a ë   û pa  \ 㝐� �ᆠ �     ᆠ  盐 ᨨᆠᨨ鼀 ᨨᨨ

 ll㡰�

é FB m  I ´ I ù m  ᔼ ´ ᔼl =  êQ p l 矄� q úû  p 2 矄� q ë l

m I é m I ҈ ù ´  - ҈㡰 ú ´҈ =  ´   - ҈㡰 㦨 ê p a ë p a  û ҈

B=

m ᔼ

  ҈ = 

m  ᔼ  꾀  p   ᆠ  㦨 �盐矄ᨨ ᨨᨨ m ᔼ m  ´  ´ ( ᔼ ⏌ ) ´ p (  ⏌  )  =   㦨   p (  ⏌ ) 

҈   = ҈  ҈ b㡰 ෌�   �盐矄㦨 �矄 ᆠ =   ⏌

 = 黨㡰⏌ = 䰘

B=0

R £ r < R 

µ0 

R

é R ù êr úJ r ûú ëê

 B

⏌

r

R

æ aö



é



N㦨҈A㦨a졔p ç ÷ 㦨a ê҈ + ú ë û èø ᨨ鼀 和ᆠ犨 犨 �ᆠ�ᨨ  ᨨ  m �矄 ᨨ盐犨  ᨨ �  졔 㜠 �ᆠ�ᨨ  \

æ   㡰 ö = çç҈ + ÷  ÷ø è

r P

R 

R r   ᆠ �  d㡰 ᆠᨨᆠ泐 �ᆠ矄  B   矄盐矄 r �  r r ҈䰘 b㡰 㝐� �ᆠ鼀ᨨ鼀 ᨨ ᆠ盐 ᆠ泐� �ᨨᨨ M = NIA

҈ m ᔼ ⏌  =   m ᔼ ⏌ 

ö ÷÷ ø

R  

µ i ᨨ r>R B = 0 pr ҈ �.e. B µ r

ᨨ犨 ᨨᆠᨨ�  =

ᆠ  æ  = çç҈ +   �矄 è

㡰 ᨨ r < ᨨ

m ᔼ b㡰 ᨨᨨᨨ  =  犨 �矄  �盐矄ᨨ ᨨᨨ

\

m I [ 矄� ° - 矄� °] p a

=

pl�

 ᨨ ᔼ = 矄� q 盐  ᆠᨨ矄 q ҈



\졠ᔴ㦨 a ´



矄� q

矄� q

矄� q



  a

᲼a㦨桌

p B Þ A = BB   㡰  盐矄 ᆠᨨ 矄�  ἘlἘ  �  ᨨ ᆠ盐  ᆠ泐� � 犨� 꾀⼄盐���盐鼀  ᆠᨨ矄q㦨l�l







Ҙ ᔼ  Ҙ ᔼ  m ᔼ   ´ ´ = ´ = p l ⏌   p l  pl

q

 ᔴ

⏌

Ҙ ᔼ 㦨맔 ᲼矄� � 졔矄� � 桌 p  ⏌ 

OC OC 㦨 OA a

҈ ҈黨

r a é pù M = Ia  ê҈ + ú kˆ  ë û

a a

a 㡰 㡰  犨� ᆠ�矄  ᆠ盐  I �    �� z㜠 �ᆠ�ᨨ ␔ ᨨᆠᨨ 矄�    鼀� �ᆠ ᆠᨨ � ur B  xy㡰�  z㦨 

WWW.JEEBOOKS.IN

EBD_8341 PS-228

Physics

ur

ur ҈ B= $� + k$ 㡰   ᆠ㡰 㝐� �ᆠ � M 盐ᨨPQ QR

㝐� �ᆠ �  B �矄 �ᆠ盐ᨨOP ur \ B = B 矄� q�ˆ - B ᆠᨨ矄 qˆ

y x  ᆠᨨ矄 q = B = r r ur m I B= y�ˆ - xˆ pr 

矄� q = \

ᨨ 

(

(

)

)

ur m I y�ˆ - xˆ  B= p x  + y 

(

m I    x 졔y 㦨r  pr y

P(x, y) r O맔

)

m I ҈ é m I ù +=  ê ú  ë  pR û pR ᲼Q㝐� �ᆠ � B㦨 泐ᨨ� ᨨ  ᆠ盐 ᆠ泐� � 矄��  ᆠᨨ 盐ᆠᨨ桌 H҈㦨

q

q y

x

®

M

B

x

R ᨨ µ P

ᆠ㡰 盐矄ᆠᨨ 矄�  鼀 ᨨ  �ᆠ├ 矄矄dxᨨ 犨� � �矄 ᆠx ᨨ鼀 ᆠ O

I⏌ I

Q

ᨨ µ S

I⏌

dx

R

ᨨµ

ᨨ犨犨  犨�QS�矄ᨨ�   H㦨 㝐� �ᆠ � M 盐ᨨPQ㡰졔 鼀� �ᆠ � M 盐ᨨQR㡰졔 㝐� �ᆠ � M 盐ᨨQS㡰

x

a O

҈ é m I ù ҈ é m I ⏌  ù m  I ++ ê  = 㦨 ê ú  ë  pR û  ë pR ûú pR  m I m I H҈ 㦨 㦨 \  pR  pR  H

b

N b-a N \盐鼀ᨨ 盐 矄�  �ᆠ├ 矄矄dx㦨 b-a 㝐� �ᆠ �  盐ᨨ �矄矄鼀鼀 O m  NI dx dB㦨  b - a㡰 x b m  NI dx m NI =  B㦨 ò a  b-a x  b - a 㡰 b dx m NI b òa x =  b - a 㡰᲼ᨨ�e x桌 a 盐鼀ᨨ 盐 矄盐 � � 㦨

m NI b 

\ B㦨  b - a 㡰 a ҈ 㡰 ᨨᨨADEFA� y㜠z  ᨨᨨABCDA�   xy  Z 泐ᆠ ᨨᨨ矄� �   ᨨᨨ矄 犨 Y E �   � ᨨ  ᨨᨨ 犨  ᨨ ├ ᆠ盐  ᨨ鼀 I AᨨD �  ᨨ ᨨ  I ᨨ鼀 D ᨨ A 쟼 ᆠ�泐 C D   �矄 ᨨᆠ盐  � 꾀 F  ᆠ  矄 犨ᨨ ᆠ ᆠ X ᨨ盐  ᆠᨨ ᆠ ᨨ  I 矄 矄ᆠ� �鼀� �ᆠ �     ᨨ�  P �矄 A B ᆠᨨ 矄�  

ᨨ�  㡰�矄�  X㜠Z 

鼀� �ᆠ �  盐ᨨᆠ盐 � ABCDA犨�� 졔 Z㜠 �ᆠ�ᨨ  盐 ᨨ 矄泐鼀鼀泐   y㜠ᆠᨨ鼀ᨨ  矄   x㜠ᆠᨨ鼀ᨨ  矄 犨� ᆠ ᆠ ᨨ盐 ᆠ  ᨨ  和�鼀�泐 鼀� �ᆠ �  盐ᨨᆠ盐 � ADEFA犨� �  x㜠 �ᆠ�ᨨ  \  �ᆠ�ᨨ ᨨ 矄盐 鼀� �ᆠ � P aa㡰



b㡰 ᆠ盐  ᨨ犨� �ᨨ盐ᨨ   ᨨ 矄ᨨ鼀� �ᆠ � ᨨ� 矄ᨨ �� ᨨ  犨�犨�盐犨 矄 ᨨ    犨� ᨨ犨 犨 矄 盐矄ᆠᨨ 矄�  ᆠ�  ᨨ� 矄 ᨨ� ᔴ 鼀� ᨨ� b犨 A B㡰 鼀� �ᆠ � ur  C 盐 ᨨ A BCA 㡰 �矄 �  盐犨  �ᆠ�ᨨ  盐 鼀� �ᆠ � C 盐ᨨB�矄�  ᨨ犨 犨  �ᆠ�ᨨ  � �矄 ᨨ ᨨ� E㝐� �ᆠ �  盐ᨨA�矄盐犨  鼀� �ᆠ

ur

ur

�  盐ᨨ�矄 ᨨ犨 犨 盐  B 쟼A  <  B 쟼B   \鼀� �ᆠ � �矄�  ᨨ犨 犨  �ᆠ�ᨨ  ur ur ᨨ�     B DA  >  B DB     �  盐犨 矄 和�鼀�泐 ᨨ  ᨨ� 矄 ᆠ   ᆠᨨ 矄�   BDA

BGB

BCA BEA

FB

FB

A D BDB

BFA

C

E

B

BGA G

BCB

BEB



 ᆠ �  㡰 矄�矄 �矄  矄 ᆠᨨ ��ᨨ  㡰 㝐� �ᆠ �   ᆠ  盐 ᨨᆠ盐 � ᆠAB m  I҈ q B҈㦨 犨 矄㡰 p r C I

 p㜠q q

A

B

I҈ I

E

WWW.JEEBOOKS.IN

PS-229

Moving Charges and Magnetism 㝐� �ᆠ �     ᆠ  盐 ᨨ ᆠ盐  �  ᆠ ACB

\

Ҙ I  ( p - q) B㦨 ᨨ犨 犨 矄㡰 p r \ 鼀� �ᆠ �    ᆠ  m  I҈ q m  I  p - q㡰 B㦨  p r p p r E E EA é lù QR =r ú = = 꾀矄ᨨI҈㦨 ê R҈ rl҈ ⏌ A rr q ë Aû  I㦨 \ B㦨 �

꾀矄ᨨ ᆠᨨ矄 q҈ =

B=

E E EA = = r ⏌ r  l R r p - q㡰  A

m é EA q EA p - q㡰 ù ´ ´ ê ú= p ë r r q r rr p - q㡰 r û

… �㡰 … ��㡰

m I ém I ù m I ´ [  + ]  = p ´  x ´ ҈ = 䰘 êë px úû  p  x

é m I ù ú 犨�├㦨䰘 ë p x û

䰘

m I c æ ö p ç a ÷ è ø

 鼀� �ᆠ �   ᆠ  C 盐 ᨨ ᆠ盐  ᆠ泐� � 犨�矄PQ RS�矄 ᨨ 㝐� �ᆠ �  盐ᨨᆠ盐 � 矄鼀�㜠ᆠ�ᆠ盐ᆠQAR ҈ é m I ù ҈㦨  ê  R ú ᲼^ ᨨᨨ盐犨 矄桌 ë ҈û ᔼ B ᔼ A

æ æ pa  ö ö I t J pa = 㡰 Ic J ç = ç  ÷÷ è  øø è m é pa  J pa  J ù  㦨  ê ú ҈ û pa ë  �maJ ᨨ  㦨 ҈ N ᔴᨨ鼀� ��犨�  maJ ҈ ␔�N㦨�  䰘㡰

鼀� �ᆠ �  盐ᨨ犨�矄  턼㦨졠 泐犨� 턼 犨�ᨨ 盐ᆠ鼀� �ᆠ �  ᨨ鼀ᨨ� 㝐^턼 Q a m é It I c ù  pa êë   úû



… 㡰

ᔴᨨ鼀� ��犨� 㦨 k ê

ᆠ盐  I 㦨 ÞI㦨꾀  A 㝐� �ᆠ �   鼀ᨨ� �ᆠ�泐 ᔴ㡰  㦨ᨨᆠ�泐

㦨

a ҈ x = =  x x

� x - a � x - ҈ x  = = =  ᆠᨨ矄 q = x x 

 ᨨ ᨨ鼀⼄ �㡰 㡰 �㡰  ��㡰

�㡰 ᔴ盐   矄�泐J㦨

m I t  pa

 PM = 黨 x  -  x  = �䰘 x =  x

Q P S R 㝐� �ᆠ �  盐ᨨᆠ盐 � 矄鼀�㜠ᆠ�ᆠ盐 ᆠSBP

҈ é Ҙ I ù 㦨 ê ᲼^ ᨨ � 犨 矄桌 ú  ë  R û \ 㝐� �ᆠ � 㦨҈ ҈ é m I ù ҈ é m I ù 㦨 ê ú- ê ú  ë  R҈ û  ë  R û m I é ҈ ҈ ù ê - ú  ë R҈ R û �ᆠ ᨨ犨 矄   �ᆠ盐ᨨ ᨨ    㡰 ᔼ  ��ᨨ    鼀� �ᆠ � �矄 盐 ᨨ ᆠ盐  �  矄ᨨ ᨨ�  ᨨ 㦨

M

�x  a㡰

I x

q P x 㝐� �ᆠ � � 盐ᨨ犨� 턼 m I ᆠᨨ矄 q҈ + ᆠᨨ矄 q 㡰 B=  p PM  ᔼ D턼㝐黨x 㦨PM졔a ᔼ D 㝐 ҈x㦨PM졔 �x  a㡰 Þ 䰘 x  = � x  - ҈ xa Þ ҈xa㦨҈x Þ a㦨҈x ᨨ鼀⼄ ��㡰 �㡰 



黨 x = PM + ҈ x㡰



… ���㡰

ᔼ  ��ᨨ r>   鼀� �ᆠ � �矄矄  盐ᨨ   ᆠ盐  �    ᆠ泐�  ᨨ ��ᨨ  r  鼀� �ᆠ � �矄 � ᨨ �  ᆠᨨ鼀鼀ᨨ  �矄 ᨨ � �ᨨ ᆠ�ᆠᨨ  �盐矄r b㡰 鼀� �ᆠ � 泐ᨨ�  � 矄�    ᨨᨨ �矄 ᨨᔴᨨ 矄�  泐 ᨨ� � 矄�   � 犨 � P 盐矄 ᆠᨨ 矄�   ᆠ�ᆠ盐 ᨨᨨ   盐矄� � 꾀鼀Ἐ矄ᆠ�ᆠ盐�犨

… �㡰

Ñò B × d l = Ҙ I

R … �㡰 … ��㡰

黨

r r

和� ᆠᆠ盐  � 矄�   ur ᨨᨨ �矄 ᨨ \ 㝐� �ᆠ �  B 㦨

WWW.JEEBOOKS.IN

EBD_8341 PS-230

Physics ¥

Þ pR  IBq =



� Q

¥

M

L R �

P

O

S



Qm㦨IA 鼀ᨨ鼀 ᨨ � �ᨨ ᆠ�ᆠ盐ᨨᨨ I =

¥



Þ pRIBq = ᨨ¥

\ 㝐� �ᆠ �  盐ᨨᆠ盐 ᆠ泐� �ᆠᨨ 盐ᆠᨨP  ᨨ�  O

Ҙ � ᲼^ ᨨᨨ盐犨 矄桌 p OR㡰 㝐� �ᆠ �  盐ᨨᆠ盐 ᆠ泐� �ᆠᨨ 盐ᆠᨨQ ᨨ� O Ҙ � B㦨 ᲼^ ᨨᨨ盐犨 矄桌 p OS 㡰 㝐� �ᆠ �  盐 ᨨ ᆠ盐  ᆠ泐� � ᆠᨨ 盐ᆠᨨ矄 L  MO�矄 ᨨ \ 矄盐 鼀� �ᆠ � O B 㦨B҈졔B 꾀矄҈ �  矄鼀 �ᆠ�ᨨ 㡰 m � m � m é ҈ ҈ ù +  =  �ê + B㦨 p OR p OS p ë OR OS úû

mR  a 

B҈㦨



mR  㡰 

mR  wq 

Þ w=

pIB Þ m

Þ T=

pm IB

p = T

pIB m

r

r

b㡰 ᨨ⼄盐 � ᆠ 泐ᆠ�ᆠ盐ᨨᨨt㦨 㝐 ´  㦨㝐 矄� q᲼q㦨p⏌桌

r

犨  鼀� �ᆠ鼀ᨨ鼀  㝐  㦨 �꾀 㦨 �p ᲼  㦨  �盐矄 ᨨ ᆠ�ᆠ盐ᆠᨨ�桌  鼀� �ᆠ � 㦨 \ t 㦨㝐矄� q 㦨�p ᲼㦨 ᨨᨨ 盐 矄桌

D Þ D 㦨 鼀� �盐  ᨨ  �盐㡰 D 鼀ᨨ鼀 盐鼀��  㦨tD㦨�p D㦨p턼  ᲼Q�D㦨턼桌

꾀矄ᨨᨨ⼄盐 t =

҈ ù é ҈  + úû 㦨҈     ë

㦨҈䰘맔҈맔 ê

Topic-3 : Force and Torque on Current Carrying Conductor ҈

ᆠ㡰 ᨨ⼄盐 ᨨ    ᨨᨨ

�



t = M ´ B = MB 矄� q = MB 矄� 黨° 㝐� �ᆠ �  B =

m I pd

꾀矄  ᨨᆠᨨ   � 犨�ᔴ�矄 ᨨ

æm I ö \ t = I҈ a㡰 ç   ÷ 矄� 黨° è pd ø

m I҈ I  m I  a  ´ a =  pd pd b㡰 㝐� �ᆠ鼀ᨨ鼀  ᨨ ᨨᨨ ABCD M҈㦨ᨨ ᨨᨨ맔ᆠ盐  r ab㦨ᨨ ᆠ �㡰 M҈ = abI 㡰 ˆ 㡰 㝐� �ᆠ鼀ᨨ鼀 ᨨ ᨨᨨ DEFA r M = abI 㡰 �$㡰  =







 鼀� �ᆠ鼀ᨨ鼀  r r r r M = M ҈ + M  Þ M = abI $� + $ 㡰

䰘

r Ҙ ᔼ Ҙ ᔼ Þ =  ҈ + = p p - 㡰 Ҙ ᔼ҈ Ҙ ᔼ = p p - 㡰 ᔼ҈ ᔼ҈ 㦨ᔼ ᔼ = ҈ ᔼ҈ - ᔼ

犨ᨨᆠ矄矄鼀泐ᨨ矄矄�� ᔼ҈>ᔼᨨᔼ>ᔼ҈ m  æ �� � �҈� ö m �� ´a = ҈ ᆠ㡰 F =  p çè a  a ÷ø p r r r b㡰  t = m ´   ᲼m㦨ᔼ꾀桌 㦨ᔼ꾀맔矄� 黨ᨨ ᲼꾀㦨p桌  Þ t 㦨ᔼp 

æ ˆ kˆ ö abI ç + ÷ ø è  ᆠ㡰 ᨨ⼄盐ᨨ ᆠ�ᆠ盐ᨨᨨt㦨MB矄� q 犨  M㦨鼀� �ᆠ鼀ᨨ鼀  B㦨鼀� �ᆠ � ᨨ犨盐矄� �t 㦨Ia \ t 㦨MB矄� q㦨Ia r Þ M  =



WWW.JEEBOOKS.IN

PS-231

Moving Charges and Magnetism 

㡰 㝐� �ᆠ 鼀ᨨ鼀  m = ᔼ꾀 =

҈

⼄ p  㡰  p

⼄w  ҈ p 㡰 = ⼄ w  p  ᆠ㡰 㝐� �ᆠ鼀ᨨ鼀 ᨨ ᆠ盐 ᆠ泐� �ᆠ �盐ᨨᨨ ᨨ 꾀�矄�� 泐㝐㦨ᔼ꾀 鼀� �ᆠ鼀ᨨ鼀  ᨨ ᆠ盐  ᆠ泐� � ᆠᨨ� �矄  ᆠᨨ  �矄 �ᆠ�ᨨ  �矄 ��  泐 ��     盐鼀 盐 ᨨ r ᆠ �盐 ᨨᨨ    ᆠ  盐 ᨨᆠ盐  �  ᨨᨨ  r 㝐 犨泐矄 ᨨ m =

黨

ᆠ㡰  ᨨᨨ 犨� 鼀ᨨ ᨨ犨 矄   犨� AB  ᨨ   ᆠ �盐ᨨᨨ犨��ᆠ ᨨ ᨨ �矄�� 犨�矄  ᆠ盐 矄   �   矄鼀 �ᆠ�ᨨ  犨 矄 CD  犨�    ᆠ盐矄 ᆠ盐 矄  �  ᨨᨨ矄� ҈ �ᆠ�ᨨ 盐矄� ᆠ �矄 ᨨᆠ F µ 犨 r�矄  �矄 ᆠ r 犨   犨�矄  ᨨ  犨�  ᆠ� ᨨᆠ ᨨ    ᆠ �盐 ᨨᨨ ᨨᆠ ᨨ  BC �矄 ⼄盐  ᨨᨨ矄�ᨨ ᨨ AD矄ᨨ 矄 ᨨᆠ矄犨�ᆠ ᆠᆠ ᨨ  I

B

C

I

A  㝐 Ä ᔼ 犨 矄

 㝐

D



҈

 ᆠ ᆠ㡰 ᆠᨨ矄ᨨ 矄 ᨨ矄 ⼄盐���盐鼀 r r ᆠ㡰 ҈ =  =  ᆠ盐矄 ᨨ  ᆠ�ᨨ    ᆠ�ᨨ  �

҈҈

㡰 ᨨ矄⼄盐���盐鼀 㝐  

mv mv 㦨qvBÞ R = R qB ҈ ᨨ R µ ᲼mqv 矄鼀桌 B R B \ ҈ =  R B҈

ᨨ盐 矄⼄盐���盐鼀 㝐  㡰 㡰 I҈ I 㦨 ᨨ矄�� ᆠ㡰 F 㦨 �� I҈ I㦨 �� 㡰 F 㦨 ᨨ矄��  ᆠ ᨨ�ᨨ  㡰 �矄   ᆠᨨᆠ  矄犨 㡰 I҈ 㦨꾀 I 㦨҈꾀 I 㦨꾀

é ҈ ù Ҙ ҈ ´ I ê + ú  X X X p R҈  ҈û ë ҈ = ᨨ R Ҙ é ҈ ù ҈ ´ I ê ú p ë X҈ X  - X҈ û X é ù X  - X҈ + X҈ X = 㦨 ê ෌�  X = ú X  - X҈ - X҈ X  -  X҈ ë ҈ û

e 졠盐犨 矄

҈

҈

r

r

҈䰘

r

r

ᆠ鼀

\

�ᆠ鼀 

҈

҈�



㡰



꾀矄ᨨ �� 錐  �  ᨨ 犨�턼 㦨�ᆠ鼀㦨�鼀 ᨨᆠᨨ 犨�턼 盐ᨨ犨�  ´  ´ ҈ ´ � FQR㦨҈䰘 ´ � � 㦨맔҈  ᨨ犨 矄 㡰 ᨨᆠᨨ 犨�턼 盐ᨨ犨�  ´  ´ ҈ FQP㦨҈䰘맔 ´ �  㦨�맔҈� ᨨ犨 矄�� 㡰  ᆠF 㦨 FQP FQR 㦨�맔҈�맔҈� 㦨맔҈ᨨ犨 矄��  b㡰 ᔼ 盐 � ᨨ鼀鼀� �ᆠ �   ᨨᆠᨨ  ᆠ盐 ᆠ泐� � ᨨᨨ�矄 ᨨ ᆠᨨᨨᆠ

ᨨ鼀ᨨ 鼀� �Ἐ矄   盐 犨 �   ᨨᆠ�矄ᆠ� � �   �泐ᨨ盐犨  �ᆠ�ᨨ

 ᨨ盐� ᨨ盐   ᆠ�ᆠ盐鼀  ᆠ ᨨ  ᆠᨨ 盐ᆠ� � ᨨᨨ b㡰 꾀矄 犨├ ᨨ犨  ᨨᆠ盐 � �  ⏌ ҈  犨 犨ᨨ犨�矄 ᆠ泐� �ᆠ盐 矄 I҈  I矄  泐 �矄 ᆠr � �

P m I I m � 㦨  ҈  =  ᲼QI҈㦨I㦨� r㦨b桌 l  pr  pb

b

X X҈

R҈  = = = X R -   - X҈

҈

  ᨨᆠᨨ  ᨨᨨEDCBE犨� ᨨ꾀矄ᨨ ᨨᆠ 盐 ᨨ 矄�鼀  FE   BA 犨�   ᨨ  ᨨᆠ  盐 ᨨ 矄�鼀  EB ur F = I ᲼ L�$ ´ B $ 桌 㦨 ILBk$ �  ᨨ矄��z �ᆠ�ᨨ 

҈黨

T盐 꾀 ᆠ盐  ᆠ泐� � ᆠᨨ� �矄  鼀� �ᆠ �ᨨ   鼀� �ᆠ ᨨᆠ ᨨ   鼀� �ᆠ �ᨨ ᆠ  �   盐 � ᨨ鼀 鼀� �ᆠ � �矄 ᨨ �㡰㝐� �ᆠ �  盐ᨨ � � �泐ᨨ �ᆠ盐 ᆠ泐� � 犨� �矄 ᆠ�矄�� 泐



B㦨

m æ � ö ç ÷ p è r ø Y

C

� A

B

P O Z d

x

X

d

ᔼ ᆠ矄ᨨ  �  �ᆠ犨�矄 矄盐  � ᆠ   ᨨ ᨨ 泐 �    ᨨ�  P �矄 犨    犨ᨨ 犨�矄 ᨨ 犨�矄

WWW.JEEBOOKS.IN

EBD_8341 PS-232

Physics

� B 盐ᨨ 犨�矄犨��  矄鼀 �ᆠ�ᨨ  矄ᨨ矄盐 B ᆠ

ᨨ  ᨨ  ᆠ � ᨨ�  P �矄   �矄 ᆠ  ᨨ鼀 ᆠ 犨�矄矄 ᨨ犨  �  ��盐   ur ur ur ur B P = B PA + B PB + B PC ur 犨  B PA 㦨鼀� �ᆠ � P 盐ᨨA ur B PB 㦨㝐� �ᆠ � P 盐ᨨB ur B PC 㦨㝐� �ᆠ � P 盐ᨨ C �ᆠ�ᨨ ᨨ B�矄�� 泐��   鼀盐

ur m ҈ ҈ ù $ é ҈ B P =  � ê + - k 㡰 p ë d + x x d - x úû ur ᨨ B P =  ҈ ҈ ҈ + 㦨 d+x x dx d 和ᨨ� �犨�x㦨 ±  ��㡰  ᨨᆠ盐 � � 犨 犨ᨨᆠ盐  ᆠ泐� � 犨�矄 m  �҈� 㦨f 矄泐㡰 p r 꾀ᆠ� � ᆠ盐 矄 �    矄鼀 �ᆠ�ᨨ  d

d B

A r

X

Z

f

҈

␔  犨�꾀�矄矄�� 泐 矄矄  ᨨᆠᨨ 盐矄�ᨨ  盐 ᨨᆠ盐 ᔼ �ᨨᨨ矄�ᨨ 犨�ᔴ犨�盐矄 �盐犨 矄  꾀 鼀泐� ᔼ  ᨨᆠᨨ ᆠ�ᨨ   �矄矄 ᔴ 犨� ᆠ�ᨨ 꾀 ��ᨨ ᨨ 꾀犨� ᨨᨨ矄矄� ␔   ᨨ �矄 矄矄 泐 �矄 ᆠx    ᨨᆠᆠ� � ᨨ  盐犨�� ᆠ矄矄  矄矄矄ᨨ� � ᨨᆠ Fmag I҈㦨A

A' r 㦨҈鼀

mg

C

I㦨A

mg m  I҈I  㦨 r p r

㝐矄矄盐 � � 㦨

zù m � � F z é =  f ᆠᨨ矄 q =   ҈  ´ ê 矄 ᆠᨨ矄 q = ú r p r l r ë û ᨨ

F m �  z = ×   l p d + z 㡰

᲼矄I҈㦨I r㦨d졔z桌





l w㦨

m �  Þ f㦨 pl pd

ᨨ鼀⼄ �㡰  ��㡰

m   I҈I  m I҈I  = ´ w   Þ  p r p rg Þ

g r

w㦨

p g 㦨

r

҈ r = p =  矄 g 黨     鼀� �ᆠ �  盐 ᨨ ᆠ盐 矄� A BPB҈   B   矄ᆠ�泐 �    �ᆠ�ᨨ 矄 �ᆠ盐ᨨ꾀  矄 矄 ᨨ犨 �  ��盐 Ð BPO㦨ÐAPO㦨 q ur ur m I  B҈  =  =  B    Z p a  + x  \ T㦨p

Y B a

xq O

㜠a A

P

B 矄� q

B

q

B҈矄� q

C

q

Bᆠᨨ矄q B҈ᆠᨨ矄q

X



졠 矄ᨨ� �B҈ B犨�  矄� q  ᆠᨨ鼀ᨨ  矄 ᆠ ᆠ ᨨ盐     ᆠᨨ矄 q  ᆠᨨ鼀ᨨ  矄   盐 \ B㦨B҈ᆠᨨ矄 q



Ҙ� m � ´  Þ w㦨 p d  pd  l

� Þ p f㦨 d

 ��㡰

 x 졔

F m �.e. = - w  z l l 㦨l wz犨�

F㦨mwz

m  I҈ I  p rg

 Öa

m æ � ö F = -  ç ÷ z ᲼矄d>>z F�矄ᨨᨨ矄�ᨨz桌 �㡰 l p è d ø

 ᆠᨨ鼀ᨨ  矄 ᨨ  ᨨᆠᨨ � x㜠 �矄 犨�  ᆠ ᆠ  Fµz 鼀ᨨ�ᨨ �矄矄�鼀 鼀ᨨ �ᆠ ᔴᨨ鼀� �⼄ �㡰犨�  矄  ⼄盐�ᨨ ᨨ 和㝐

ᨨ

D

m   I҈I  mg x 㦨  r p r 和� ᆠFµx  �ᆠ ᨨ⼄盐���盐鼀ᨨ矄��ᨨ 

 ᨨ   鼀ᨨ�ᨨ  �矄 矄�鼀 鼀ᨨ �ᆠ m   I҈ I  \ 㦨 鼀矄矄盐 � � 㡰w Qa㦨lw㡰 �㡰 p r 

B

ᔼ  犨�B�矄 �矄ᆠ ᨨ �Z㜠 �矄泐矄鼀 �矄 ᆠ F Z 矄ᨨ� � ᨨᆠ盐 � �  ᨨ  犨�B 盐 l ᨨ犨�矄A C犨�

B'

矄ᨨ� � ᨨᆠ⏌ � F㦨

꾀⼄盐���盐鼀

Z

x

m   I҈ I  m  I҈ I  矄ᨨ� � ᨨᆠ⏌ �  㦨 p r - x p r m ҈ ù m I I x é ҈ - ú 㦨  ҈   I҈I  ê 㦨 p ë r - x r û p r r - x㡰 ␔  x�矄矄鼀�.e.xr  r㦨x»r

f

q q

B

A

m pl

㦨

m p

I 

a +x



´

x 

a +x



=

m  Ix p a  + x  㡰 ᨨ犨 矄  Y �ᆠ�ᨨ 㡰

WWW.JEEBOOKS.IN

PS-233

Moving Charges and Magnetism 盐矄 ᆠᨨ 矄� 矄鼀ᨨ�ᨨ ᨨ 犨�OC P ᨨ  � dx ᆠ盐矄 鼀� �ᆠ �  ᨨ 盐ᆠ   �   ᨨ� 矄 ᨨ 졠ᔴ犨� �  㡰 矄鼀鼀ᨨ盐 ᨨ  ᨨᆠᆠ� � ᨨ    矄鼀 ᨨ�ᨨ

黨 黨 ´ ҈҈ I B ´ ҈҈ = 㦨꾀 Þ IB㦨   ҈ ��㡰  �鼀 矄�ᨨ 矄 ��  矄 ᨨ犨矄   SA졔SB㦨AB\ ÐASB㦨黨 泐泐 �ᨨᨨ盐矄  ᨨ鼀㡰 㝐� �ᆠ �  盐ᨨAS m  I A m  ´ 黨 × = ´ BSA㦨 �ᆠ Sᨨ B㡰  p rSA  p ҈ 㝐� �ᆠ �  盐ᨨB S m  I B m  ´  × = BSB㦨 �ᆠ Sᨨ A㡰  p rSB  p ҈ 和� ᆠBSA BSB鼀盐盐泐 �ᆠ盐 \  鼀� �ᆠ �  Þ

ur ur ur dF = I dx ´ B㡰 \dF㦨I dx B矄� 黨

m  Ix Þ dF 㦨I dx맔  ´  p a + x  㡰

xdx m Þ dF㦨   I   p a + x  㡰 \

ᨨ ᨨᆠF㦨

L m xdx ´ Iò   p a + x  㡰

L

m é҈ ù ´  I  ê ᨨ� e a  + x  㡰 ú 㦨 p ë û



é m a + L ù ´  I  êᨨ�e ú p a ûú ê ë ur

 �ᆠ�ᨨ ᨨ  F �矄ᨨ犨 矄Z �ᆠ�ᨨ 矄 鼀� �矄矄     盐 ␔   �ᆠ�ᨨ  ᨨ  ᆠ盐  �  B �矄 矄   鼀� �ᆠ �  �矄 ᨨ �   ᆠ盐   ᆠ ᨨᆠ F㦨IlB矄� q q㦨҈ �矄 ᨨ  犨ᨨ犨�矄 �ᆠ盐ᨨ  ᨨ    犨�꾀ᆠ�矄ᆠ盐  �ᆠ � ᨨ  ᨨ 

ᆠ盐 � 犨�B矄 ᨨ盐 � 盐犨  �ᆠ�ᨨ 矄ᨨ矄 ᨨᆠ ᆠ 鼀� �ᆠ �  盐ᨨA P 泐��  

盐鼀 盐㡰

m æ 黨 ö æ  ö   B 㦨 BSA + BSB =  ç ÷ +ç ÷  p è  ø è  ø 㦨҈䰘맔҈㦨҈맔҈

���㡰 ᨨᆠ盐 � �  ᨨ 犨�B

Þ F 㦨



m I A I B p rAB ҈-䰘 ´  ´ 黨 ´  㦨 㦨맔҈䰘⏌鼀 

㦨

Topic-4 : Galvanometer and its Conversion into Ammeter and Voltmeter ҈

A ´

㡰 ෌ ᨨ鼀 ᨨ  矄�矄 ᆠ ෌㡰 ᆠᨨ   � ᨨ  ᨨ鼀ᨨ  �㜠҈ R҈ ෌ �g

V = ҈ = �g G + R҈ 㡰

鼀 ҈

鼀

෌ R҈

10 m 11

S

҈鼀

 �㡰

ᨨ� ᆠ矄  �ᨨ ᨨ鼀㜠

 = �g R҈ + R + G㡰

 M BA

P

BB N

�㡰 鼀� �ᆠ � P 盐ᨨᆠ盐 � 犨�A

m  I A m  ´ 黨 = ´  �ᆠ�ᨨ PᨨM㡰 �㡰 ҈ ö p rAP p æ çè  + ÷ø ҈҈

鼀� �ᆠ � P 盐ᨨᆠ盐 � 犨�B BA㦨

I m m  ´ 黨 ´ = ´ B ҈ ö p æ ҈ ö p æ çè  + ÷ø çè ÷ø ҈҈ ҈҈

 ��㡰

�� � �⼄ �㡰泐 ��㡰 G + R҈ ҈ Þ =  G + R҈ + R

B

m I B ´ BB㦨 p æ ҈ ö çè ÷ø ҈҈ ᨨ鼀⼄ �㡰  ��㡰

R



Þ G + R҈ + R = G +  R҈ \ R = G + R҈ 㡰 ෌�  ᔴ盐 矄矄� � ᨨ盐�  � ᨨ鼀 I 㦨  鼀꾀  ᆠ�ᨨ q㦨 ��盐 ᨨ 鼀� ᨨ � ᨨ鼀 I  ´҈- = =  ´҈- 꾀⏌ �  q ᨨ 盐矄㡰㦨�� 졔෌㡰 Þ�㦨҈ 맔҈졔 㡰 㦨҈黨�맔҈W ᆠ㡰 㦨�� ෌졔 㡰㦨맔҈ �졔�㡰㦨 㡰 Cq㦨NB�A矄� 黨 æ p ö = ҈䰘�B ҈- 㡰 ´ ҈- ᨨ ҈- ç è ҈ ÷ø \B㦨҈

=

 ��㡰   �

WWW.JEEBOOKS.IN

EBD_8341 PS-234



Physics

b㡰 ␔   ├泐⧤҈ �矄 ᆠᨨ矄   ├泐⧤ �矄 ᨨ

쟼 �� = = ᔴq   + � ␔   ᨨ    ├泐矄  ᆠᨨ矄

 �㡰

ᔴq  쟼 � æ ö ´ = ç � � ÷ � + �㡰 � ç  + ÷ + � è �ø ᔴq  �쟼 Þ =  ��㡰 � � + ҈҈ � 쟼 = ᔴq  �㡰  + � �� � � �㡰泐 ��㡰犨� � � + ҈҈ Þ =� ҈҈ + � � Þ��졔� �㦨� �졔҈҈  �㦨 �㦨W b㡰 ෌ ᨨ鼀 矄� ��矄�ᨨ 矄ᔼ�㦨맔҈맔�㦨҈꾀 ෌ � � �� =

䰘

�W 



黨

҈

҈ ´ ҈ ´ 䰘 ´ ҈-  和= = ҈҈ W æ ö -ç ÷ è ø ҈҈ ᆠ㡰 ෌�   ᔴ盐   ᨨ盐�    � ᨨ鼀 �g㦨�맔҈A ෌ ᨨ鼀矄�矄 ᆠ G 㦨 ҈�W 矄�矄 ᆠ Rᨨ盐� 矄�矄 犨�  � ᨨ鼀 ᨨ ᆠᨨ  � � ᨨ  ᨨ鼀 V㦨�g R졔G㡰 ҈㦨�맔҈ R졔҈�㡰 \ R㦨҈�㦨҈黨�㦨҈黨�맔҈W ҈ ᆠ㡰 ᔼ�෌㦨 ᔼᔼ�㡰矄 \҈맔҈㦨 ҈҈㡰맔和 \和»҈W  ҈ 㡰 꾀ᆠᆠᨨ � �ᨨ졠 鼀Ἐ矄犨 ᔼ =  ᔼ� 㦨 졔 ෌ 犨 ᔼ�㜠෌ ᨨ鼀ᆠ盐 ෌㜠෌ᨨ ᨨ鼀矄�矄 ᆠ ᔼ෌ ෌ ҈҈ ´ ҈ ´

㦨ᔼ� 







�

␔   矄 盐  ᨨ  矄�矄 ᆠ 和 �矄 ᆠᨨ

ᆠ   ᨨ   ෌和 ෌ ᨨ鼀    ෌ 㦨 ෌졔 和  \ ᔼ㦨 ෌和 졔 ෌졔 和 ᔼ෌  ෌

㦨ᔼ� ෌졔 㡰 �㦨 �졔 㡰҈\ 㦨W ᆠ㡰  ᆠ�ᨨ  ᆠ盐  㦨ᔼ�鼀 㦨 ├㦨�맔 ␔  㦨盐鼀ᨨ  ��矄�ᨨ 矄㦨 ├㦨�鼀⏌ ��矄�ᨨ

㦨҈�맔҈㦨҈� 㦨ᔼ�᲼졔 桌 ҈�㦨҈�᲼졔 桌 ҈㦨졔 㦨W 㡰 ෌�  矄�矄 ᆠᨨ � ᨨ鼀 G㦨҈W ᔴ盐 ��㦨҈mA 꾀 � ᨨ鼀 ᆠ   ᆠᨨ   � ᨨ ᨨ鼀 泐 ᆠᨨ

ᆠ� �  � 矄�矄 ᆠ  �  矄�矄 犨�  �

ᨨ矄�矄 ᆠᨨ   ᆠᨨ鼀� �ᨨ 㦨 G졔 R 꾀ᆠᆠᨨ � �ᨨ졠 鼀矄犨V㦨�� G졔R㡰 \҈㦨҈맔҈ ҈졔R㡰 Þ҈҈㦨黨黨W㦨  Þ 㦨黨黨├W b㡰 ��盐ᨨ 鼀�ᨨ � ᨨ鼀�矄 ᆠᨨᆠ⼄盐� ᨨᨨ 盐ᆠ  ᆠ�ᨨ ᨨ ᨨ  ��矄�ᨨ �  � ᨨ鼀 ᔼ � ��盐ᨨ 鼀� = q e ҈ ᔼ=  ෌ = ⧤W +෌ 黨 ҈ e 和 ҈ e和 = ´ Þ =  + ෌和 和+ ෌  和 + ෌㡰 + ෌和 和 ෌+和 ෌



҈ ᔼ  和= + ෌㡰ᔼ  e ෌ ´

和 쟼⼄盐 ᨨ � �  ᆠ �矄 ��  泐

ᔼἘ� ෌ 㦨 ᔼ 㜠 ᔼἘ� 㡰和 ᔼ Ἐ� ෌ + 和㡰 = ᔼ和





=

Þ ෌ + 和 + ෌和 = 和 + ෌㡰 Þ ෌ = 和 + ෌㡰 - 和 + ෌㡰 \ ෌ = 和 + ෌㡰

ᔼ⏌

҈

ᔼ�

ᔼ和  ෌+和   和 Þ = ´  + ෌ 㡰 + ෌和 ෌+和 ෌ +和 ҈ 和 Þ =  + ෌㡰 ෌ + 和㡰 + ෌和 Þ ෌ + 和㡰 + ෌和 = 和 + ෌㡰 Þ

��㡰  ҈ q㦨 㦨�

᲼෌� 㦨 ᔴ㦨҈鼀

WWW.JEEBOOKS.IN

PS-235

Moving Charges and Magnetism 꾀㦨맔҈鼀桌 ␔├ ᨨ犨ᔴq㦨꾀ᔼ�

҈䰘

Cq ҈   ´  㦨҈꾀 㦨 NBA � ´  ´҈  ´ 

ᨨᆠᨨ � ᨨ鼀ᨨ鼀鼀矄 盐 矄�矄盐矄 �

 ᨨ   � ᨨ鼀 ᔼ�맔෌㦨 ᔼᔼ�㡰和 \ ᔼ�㦨

҈ ´ � � \ 和㦨 㦨 㦨 㦨��W I  Ig ҈  ҈ 黨 ҈� b 㡰  ෌ 㦨 ҈W錐 ᔼ� 㦨  맔 ҈꾀  㦨 ҈ 鼀 㦨҈ᔼ㦨҈꾀 矄� �㦨ᔼ� ෌졔 㡰᲼  㦨 矄�矄 ᆠᆠᨨ

ᆠ � 矄�矄 犨�  � ᨨ鼀桌 Þ҈㦨맔҈  \ 㦨�맔҈ W  矄�矄 ᆠᨨ ᨨ鼀㡰 꾀矄ᨨᔼ�෌㦨 ᔼᔼ�㡰矄 맔҈맔҈㦨 ҈맔҈㡰矄 \和㦨맔҈W 矄�矄 ᆠ ᨨ  鼀鼀㡰 I gG

bᆠ㡰 ᨨᆠᨨ 鼀鼀� ᨨᨨ鼀 �� 矄�矄 ᆠ �矄 ᆠᨨ

ᆠ  �  矄�矄   ᨨ犨 矄�矄 ᆠ�矄 ᆠᨨ

ᆠ  �

ᨨᆠᨨ � ᨨ鼀� ᨨ 鼀鼀 ᨨV㦨Ig G졔R㡰㦨�맔҈�᲼҈졔桌㦨҈

æG ö é҈ ù + ҈÷ = � ´ ҈-� ê + ҈ú 㦨�鼀꾀 èS ø ë ҈ û

ᨨI㦨Ig ç ҈

θ NBA ᆠ㡰 和 矄���泐ᨨ 鼀ᨨ� �ᆠᨨ�� ᨨ鼀㦨 㦨  ᔼ C θ ᔼ � ᆠ矄矄泐盐矄� ��ᨨ ᆠᨨ �.e.錐矄 矄���泐� ᆠ矄矄 ᔼ 和ᨨ  �ᨨ ᆠ  矄�泐鼀� �矄   鼀� �  

Topic-5 : Miscellaneous (Mixed Concepts) Problems ҈

ᆠ㡰 盐矄 ᆠᨨ 矄�   鼀  �  dl 矄盐 � � 

 � dq    ᆠ  ᨨ    ᆠ�ᆠ �졠  FB    鼀� �ᆠ ᨨᆠ ᆠ� � ᨨ   �矄  � 

Tᆠᨨ矄  q 

෌和 ҈ ´  꾀 = = » W ෌ + 和 ҈ + 

ᔼ=

T

쟼 쟼 = � ´ ҈ +  黨҈ �҈

 =

 q 

 쟼 黨黨 = ´ = 黨黨W ᔼ 黨҈ 쟼 ⏌ 黨҈ 

T矄�  q  T矄�  q 

 q  q  

I

쟼 � ´ ҈ 쟼 ´ = ´ 黨黨 黨҈ �҈ 黨҈

\ 鼀矄盐 =

Tᆠᨨ矄  q 







é ᆠ dl 㡰 ù êQ  � q㡰 = ú  �盐矄 R û ë

꾀⼄盐���盐鼀 T 矄� ç

\ E㦨黨黨黨鼀 和� ᆠ�A㦨҈꾀

҈

I

L æ q ö q ÷ = BI p   è ø

E æ ҈ ö  ´ç ÷ ´ � ´҈ 黨 è �҈ ø

\ 㝐 �鼀盐鼀 � �ᨨ R㦨

R

Lù é æ Lö = BI ç ÷ d q êQ pR = L Þ R = p ú è p ø ë û T  矄�ᨨ �  犨�ᆠ� �ᨨ �ᨨ  矄ᨨ   鼀   � 

ᔼ    ᨨ鼀 矄 ᨨ犨矄 盐 矄ᆠ  ᆠ�ᨨ   

҈㦨

T

\ FB 㦨BI dl㡰 盐犨 矄㡰 㦨BI Rdq㡰

 ҈W 

 q 

Þ T

黨黨黨 ´҈  ҈ ´ ҈

㦨黨黨黨W

 ᆠ㡰   � ᨨ  ᨨ鼀 V㦨Ig Req졔G㡰 \ 㝐 �鼀盐鼀 ᨨ� ᆠ   ᨨ�   �  ⼄盐�  矄�矄 ᆠ ᨨ  ᆠᨨ鼀ᨨ  矄 �矄 鼀 �鼀盐鼀 �.e. 犨      ᆠᨨ鼀ᨨ  矄  ᆠᨨ

ᆠ  �  矄�矄

 �ᨨ 鼀鼀

G ö æ I㦨 I g ç ҈ + ÷ è S eq ø \ 㝐 �鼀盐鼀ᆠ盐  �ᆠ ᨨ�  � ⼄盐�  矄 盐 矄�矄 ᆠ�矄鼀� �鼀盐鼀�.e.犨   ᆠᨨ鼀ᨨ  矄  ᆠᨨ

ᆠ  �  

dq L = BI dq  p

é dq ù êëQ  泐㜠泐矄鼀 úû

BIL p 㡰 鼀� �ᆠ� 矄ᨨ  ᨨᆠᆠ  盐ᨨᆠ盐 犨�  �  矄盐ᆠ   犨泐  ᨨ  x  y    矄 � 矄 犨�   �ᆠ盐 矄� 矄犨�� ᆠ�ᆠ盐ᨨᨨ矄  盐鼀 ᨨ � 矄 鼀ᨨ� � ᨨ犨 犨 矄 �  x  y   犨�  矄鼀 �

盐鼀ᨨ ᆠᨨ鼀� �盐犨 矄ᨨ  x  y   ᨨ ᨨ鼀� �ᆠ 盐  ᨨ盐� xy 犨� ᨨ 㡰   鼀� �ᆠ �  盐 ᨨ ᨨ    犨�矄 犨�  ᨨ犨 犨  矄 矄 ᨨ犨  ᨨ犨 �    ��盐 和� ᆠ  � ur r 犨  v   B �矄҈  ur r ur

 ᨨ 鼀� �ᆠ ᨨᆠ F m = q v ´ B㡰 =  \ T =





WWW.JEEBOOKS.IN

EBD_8341 PS-236

Physics Z

v

 Y

I

㜠I

X ␔�矄� X㜠Y     ᨨᆠ�泐� Z㜠 �ᆠ�ᨨ

B

d



㡰 꾀�矄 ᨨ �x㜠 �矄vx㦨

y mv mv r҈㦨  r㦨 qB҈ qB

d҈ + d  t҈ + t

v r҈

Q҈㦨

�

B 

\

䰘

r҈㦨r

r B҈

r B

r

x

 p r  LR

  ⏌ 䰘㡰 ҈㡰 㦨�黨ᨨ;  ҈㡰 �㡰

R )

Z

BR B



I҈ 졠

P

Z

I Y



æ m pr  ö dI ᨨ M㦨  ç  ÷×  �㡰 è LR ø dt ෌� I㦨Iᆠᨨ矄 t㡰

N㦨

(

X

æ m pr  ö dI df = ç  ÷× è L ø dt dt

æ  p  r  ö ÷ m I  矄� t 㡰 M㦨 ç è LR ø

P

r m I ⼄盐ᨨ B =  - kˆ㡰  R

æ m I ö  f㦨BA㦨 ç ÷ pr 㡰 è L ø

dI 㦨I矄�  t㡰 dt

I

R Y ᆠ㡰 ᔼ I҈ I>   � 鼀� �ᆠ � ᨨ���

犨�  � Z �ᆠ�ᨨ     鼀� �ᆠ � r 盐 ᨨ I  ᨨ��� 犨�矄ᨨ� Z �ᆠ�ᨨ   ᨨ B   ᨨ���

ᆠ

ᨨ  ᨨ 㡰 ᔼ I҈㦨I   矄盐 ᨨ  鼀� �ᆠ �   P�矄ᨨ �졔X �ᆠ�ᨨ   ᨨ 鼀� �ᆠ � �矄 ᨨ 泐 盐 ᨨ   ᆠ盐  ᔼ 犨 �ᆠ  �矄 �  Z �ᆠ�ᨨ    �矄

Iù m I é Q n� = ú ê ë L û L 盐 矄矄� �  ᨨ盐�    ᆠ�ᆠ盐 ᆠᨨ�

\

I 졠

\ 㦨

æ m pr  ö dI e ᔼ 盐ᆠ ᆠ盐 �㦨 =  ç  ÷× R è LR ø dt 㝐� �ᆠ鼀ᨨ鼀 M㦨�A㦨�pr

 �ᆠ�ᨨ ᨨ  ᨨ犨ᨨ ᆠᨨ 矄�矄ᨨᨨ矄�ᨨ ᨨ ᆠ盐  盐ᨨ �矄 ᨨᆠ ᨨ犨� �ᨨ  ᨨ �ᨨ   ᆠ 꾀ᔴ 矄 ᆠᨨ  ᆠᨨᆠ    �矄 ᆠ b 㡰 㡰 ᔼ I҈㦨I   鼀� �ᆠ � 矄 盐ᨨI҈  Iᨨ��� Ἐ졠Ἐ犨�ᆠ ᆠᨨ盐ᆠ ᨨ 盐 鼀�㜠

�ᆠ � Ἐ졠Ἐ 盐ᨨ � �犨�矄   ᨨ ᆠ

ᨨ  ᨨ ᨨ���  㡰 ᔼ I҈> I   鼀� �ᆠ �  盐ᨨᨨ ᆠ盐  犨� �  졔 Z �ᆠ�ᨨ     㜠盐 鼀� �ᆠ �  盐ᨨᆠ盐 ᔼ犨��  Z �ᆠ�ᨨ  � �矄鼀�㜠

�盐  �矄 ⼄盐 ᨨ   ᆠᨨ鼀�   鼀� �盐 矄 ᨨ  I҈   I   ᆠ  ᨨ ᨨ���  X I҈ R

pm

�鼀矄 泐ᆠ � �ᆠ� B҈t҈㦨 qB҈ pm

�鼀矄 泐ᆠ � �ᆠ� Bt㦨 qB

ᨨ �矄 ᆠ ᨨ � x㜠 �矄 d҈졔d㦨r҈졔r㦨 r҈졔r㡰㦨 �r㡰㦨҈r ҈ r mv qB 꾀�矄 㦨 �t 㦨  qB ´ pm   㦨鼀矄҈ Qv㦨p鼀矄҈㡰 㡰 ᔴᨨ 矄�  ᆠ�ᆠ盐盐矄ᨨ �矄ᨨ ᨨ�  犨�矄  ᆠᨨ矄泐犨ᨨ盐  㝐� �ᆠ �  � 矄�   矄ᨨ ᨨ� 㦨mn�

ᔼ 盐ᆠ 鼀 e㦨 

ur r ur

 ᨨᆠ  � ᆠ 泐鼀ᨨ� � ᆠ � F = q v ´ B㡰 㦨 - e㡰 - v�$ ´ B $ 㡰 㦨evB k$

黨

I

df  ᨨ�  �ᆠ� �矄� 盐ᆠ 鼀 dt 犨�矄鼀盐ᆠ盐 矄犨� �  ෌� hA>hg æ v ö  ᆠVA>VB矄 çç h =  g ÷÷  è ø ᔼ rA>rB  IAIBᔼ  �矄ᆠ矄�� ᆠᨨ ��ᨨ ᆠ  盐 � � mAmB ᔼ rArB  IA>IBᔼ  �矄ᆠ矄�� ᆠᨨ ��ᨨ ᆠ  盐 � � mA£mB 꾀⼄  盐ᨨ盐犨��  ᨨ犨 犨  �ᆠ�ᨨ   盐ᨨ ᨨ犨犨�� 盐犨  �ᆠ�ᨨ   ᆠ q �矄 ᆠᨨᆠ 꾀矄P�矄 鼀� ᨨ�  犨ᨨ鼀� �ᆠ � 矄ᆠ ᆠᨨ盐 ᆠ  ᨨ   ᨨ r �矄 ᆠᨨᆠ   盐ᨨᆠ盐 � ᨨᨨA�矄ᨨ �  �� ᨨ犨 矄 ��    盐 ᨨ ᆠ盐  �  ᨨᨨ B �矄 矄ᨨ ᨨ �    � �  ᨨ犨 矄 ��  b 㡰ᔼ 盐ᆠ 鼀  e = 

WWW.JEEBOOKS.IN

PS-237

Moving Charges and Magnetism

҈

҈҈

҈

 ᆠ   盐ᨨ ᆠ盐 矄 �   犨�矄 �    矄鼀 �ᆠ�ᨨ  ᔴ⼄

鼀� �ᆠ �  盐ᨨᆠ盐 � ᨨᨨAP�矄⼄盐 ᨨᨨ矄�ᨨ 鼀� �ᆠ �  盐ᨨᆠ盐 � ᨨᨨBP ⼄矄 �P 盐ᨨᆠ盐 � �

ᨨᨨ�矄 �ᆠ盐ᨨ    ᨨ   �ᆠ  �ᆠ泐盐犨 矄 �P 盐ᨨᆠ盐 � ᨨ盐ᨨᨨ�矄 �ᆠ盐ᨨ    ᨨ   �ᆠ  �ᆠ泐 ᨨ犨 犨  꾀矄   ᆠ盐   �  ᨨᨨ矄� �ᆠ�ᨨ    犨�矄  ᆠ  ᨨ 盐  ᨨᆠᨨ  ᆠ  犨��矄 ᨨ 꾀⼄

鼀  �泐�矄 �   �   犨� 犨    ᆠ � ᆠᆠ�ᨨ �矄 ᆠᨨ

ᆠ  ᨨ   矄 ᨨ    犨�  � ᆠ盐  ᆠ矄� �� 鼀� �盐 犨� �鼀㡰矄矄矄 ᨨ盐�   犨� 矄 ᨨ犨  矄 矄�矄ᨨ㡰  ᨨ � �  ᆠ ᆠᨨ矄矄   犨� 矄ᨨ ᆠ矄矄 犨�  �鼀  ᆠ � ᨨ

  ᆠᆠ�ᨨ  矄ᨨ ᆠ矄矄 犨�  �鼀 矄

 犨� �矄 鼀ᨨ   �ᆠ盐 ᨨ�矄  �  l㡰 犨�   ᆠᨨ 矄  ᨨᆠ�泐 v㡰�   盐 � ᨨ鼀鼀� �ᆠ �  㡰^ ᨨ   ᨨ 鼀ᨨ�ᨨ e 㦨Blv ␔  B l v  ᆠᨨ 矄   �矄 ᆠᨨ 矄  꾀 ᆠᨨ 矄  ᨨ � �  ᆠ ᨨ矄 ᆠᨨ矄矄    矄 ᨨ    犨�   ᆠ �矄 ᨨ ᆠᨨ 矄  鼀� �盐      矄 ᨨ   犨� ᔴ矄 ␔   犨� �矄 ᆠ  鼀 ᆠᨨ 矄  ᆠ�ᆠ �   矄  �ᆠ�ᨨ  ᨨ �    �  ᨨ    犨�   ᆠᨨ 矄 鼀ᨨ 盐    � 盐 ᆠ ᨨ ᆠ�ᆠ �  ᨨᨨ矄� ᨨ   �ᆠ�ᨨ  ᨨ ᆠ�ᆠ �  �矄 鼀ᨨ鼀  ᨨ e ᆠᨨ � 盐矄 �   ᆠ�ᆠ �  � 矄�    犨� �矄 ᨨ ᔴ �矄 ᨨ ᆠᨨ 矄  鼀� �盐       矄 ᨨ   犨� ⼄ 和� ᆠ emf ᨨ   泐 E R  ᆠᨨ 矄   ᆠᨨ 矄  ᆠ盐  ᨨ犨矄 �  犨�盐ᨨ � � ᆠᨨ ᆠ盐   鼀  �泐 �矄 �   �    犨� 꾀矄ᨨ  ᆠᨨ 矄  ᨨ � �  ᆠ ᨨ矄犨   矄ᨨ  犨� 꾀錐⼄矄錐ᔴ⼄矄錐⼄矄 꾀㡰 ᔴ �ᨨ  �ᆠ�ᆠ� � 犨�ᆠᆠᨨ矄�ᆠ � 犨 �ᆠ  �矄 �鼀 �    㡰 ᨨ� �ᆠ ��矄�├ᆠ盐  �矄犨�ᆠ 鼀� �ᆠ �  鼀� �ᆠ鼀ᨨ鼀  ᔴ㡰 ᔴᨨ 矄  ᆠ盐  �  � � 矄ᨨ  ᆠ � �矄 ᨨ   犨�  ᨨ �鼀 �    ᆠ�ᆠ �   ᆠ盐  ᨨ 盐ᆠ矄 鼀� �ᆠ �    鼀� �ᆠ 鼀ᨨ鼀  㡰 � 㦨 �  ᆠᨨ矄 wt錐꾀 ᆠ  �� � 鼀� �ᆠ �  犨�  ᨨ 盐ᆠ  �矄 犨� ᆠ  � 盐ᆠ  ᆠ�ᆠ � 꾀矄ᨨ  ᆠ  �� � 鼀� �ᆠ 鼀ᨨ鼀  犨�  ᨨ 盐ᆠ   㡰␔   鼀� �ᆠ ᨨᆠ ᆠ矄 ᆠ�ᆠ ᨨᆠ FB㦨FE Þ q vd B㦨q E \ vd B㦨

V w

᲼Q V㦨E맔w桌

é I ù ú´B ë newd û

\ V㦨wvdB㦨 w ê \ V =

I ´B ned

ᨨ V µ

҈ d

Þ

V҈d҈㦨Vd

I I ù é êvd = neA = newd ú ë û

ᔼ d҈㦨dV㦨V҈  � d҈㦨dV㦨V҈ ҈

ᆠ㡰 Q㦨

I ´B ned

Vn V n B Þ ҈҈=   n B҈ B ᔼ B҈㦨B n҈㦨nÞV㦨V҈  vfB҈㦨B n҈㦨nÞV㦨�V҈ ҈ ᆠ㡰 B҈矄� q  B矄� qᆠ ᆠ  ᆠ ᨨ  \ V µ

B B矄� q

P

q q 黨ºq㡰 B

B҈矄� q B҈

q B q B҈ᆠᨨ矄졔ᆠᨨ矄 

a +h



h q ␔�҈ a a ␔� ᨨ ᨨ鼀� �ᆠ � �P 㝐� �ᆠ �  盐 ᨨ ᆠ盐  ᆠ泐� � ᆠ�ᆠ盐 ᨨᨨ 㦨 㝐� �ᆠ �  盐ᨨ矄��  犨�矄 B㦨B҈ᆠᨨ矄q졔Bᆠᨨ矄q㦨B҈ᆠᨨ矄q

é m I  ê 㦨  ⏌  êë  p a  + h   a + h

m Ia 

(

҈�

)

ù a ú´  úû a + h

和ᨨ� � 犨 � h»҈a

ᆠ盐 �矄 ᨨ鼀PᨨQ RᨨS� 犨�҈ 犨� 矄ᆠ�泐 b㡰 ␔ ├ ᨨ犨 ᨨ⼄盐 r r r t = M ´ B 㦨MB矄� q

(

)

m Iù é 㦨 I ´ pa  ´ ê ´  ú 矄� °  pd û ë

҈ ҈䰘 ҈ ҈黨

m I a \ t㦨  d 㡰 ��ᨨ ᨨ  � �矄 盐ᨨ鼀� �ᆠ盐矄�ᨨ 

 鼀� �矄  ᆠᨨ�矄 盐

� � ᨨ �   ᆠ├  � 鼀� 矄 ᨨ    � Ἐ矄 盐  ᆠ�� 㡰 �� � ��ᆠᨨ矄 b㡰 㝐��矄 ��ᨨ ᨨ 鼀� �ᆠ��ᨨ   鼀� �ᆠ ᨨᆠ犨�盐 鼀�� 矄 㡰 ᨨ⼄盐ᆠ� �ᨨ ᆠ �盐ᆠᨨ�ᆠ � 盐 � ᨨ鼀 鼀� �ᆠ � r uur ur t = M ´ B  Þ t = MB 矄� q M㦨N � A  q 㦨黨  ᨨ鼀ᨨ� �ᆠᨨ�� ᨨ鼀㡰 \ t㦨N � A B矄� 黨 㦨N � A B t㦨k � �� 㡰 \ k �㦨N�AB Þ k㦨NAB 㡰 ᨨ矄�ᨨ  ᆠᨨ 矄  ᔴ 㦨

t N�AB = q q

WWW.JEEBOOKS.IN

EBD_8341 PS-238

Physics ᨨ鼀⼄ ��㡰  ���㡰

෌� �㦨� q = p ⏌   N � A B \ C㦨 p ᆠ㡰

T҈㦨

 �㡰

ò tdt 㦨 ò N�AB dt 㦨NAB ò � dt  Qt㦨N�AB㡰

㦨NABQ

ò t dt = I w NABQ I  盐矄 泐   犨 ᨨ   �泐 ᆠᨨ 矄�ᨨ  ᨨ �     � ᨨ  ᨨ�ᨨ  ᨨ�ᨨ  ├� �ᆠ  �泐 ᨨ  ᆠᨨ� 㦨 ᨨ �  �泐  鼀 �鼀盐鼀  ᆠ�ᨨ

҈  ҈  I w = C q 鼀 l   ҈ æ  NIAB ö  ҈ æ NABQ ö Iç ÷ q鼀 ÷ 㦨 ç è p ø  è I ø

pBNA I ␔     犨  �矄 ᨨ ᨨ� � ␔ ᨨ 犨 㦨  矄�ᨨ � 矄� � mg㦨T

\ T㦨

mg 

 �㡰 d



T w

P

O

B

␔    犨  �矄 ᨨ� �   鼀� �ᆠ �  �矄 � 鼀� �ᆠ鼀ᨨ鼀 

Q Q 맔pr㦨 w맔pR T p ᨨ犨  矄�ᨨ 矄�   矄� �矄 犨�ᆠᨨ鼀盐 ⼄盐    矄�ᨨ 矄�    矄� �矄 T҈  T ᨨ 矄�ᨨ ⼄盐��b�盐鼀 T҈졔T㦨鼀�  ��㡰

ᨨ⼄盐 ᆠ� � ᨨ    � � ᨨ盐   ᆠ  ᨨ � � r uur ur t= M ´B t㦨M맔B맔矄� 黨 M㦨�A㦨

Q QwBR  w ´ pR  ´ B = p  ᨨ ᨨ�ᨨ  ⼄盐���盐鼀   ᨨ⼄盐 ᨨ盐   ᆠ  ᨨ � � 矄 ᨨ盐   ᨨ t㦨

QwBR  d

dT

BQR  ҈ 㝐� �ᆠ �  ᨨ 盐ᆠ  泐   ᆠ�ᆠ盐�  �矄 ᆠ  B㦨B�

ᆠ矄졔Bᨨ盐ᆠ矄 矄 矄��   ᨨ   ᆠ�ᆠ盐� 犨� ᨨ 盐ᆠ ᨨ 鼀� �ᆠ �    ᆠ  m� m� + \ B㦨  r҈ r ᲼෌� �㦨҈꾀r҈㦨鼀 r㦨҈鼀桌

҈ ö m æ ҈ ´ ҈ ´ ç + ÷  è  ҈ ø \ B㦨 �맔҈�㡰T ᲼^ ᨨ    ᨨ盐犨 矄桌 ᨨ鼀��    盐鼀盐㡰 㡰 ᨨᆠ ᆠ� � ᨨ   ᆠ盐  ᆠ泐� � ᆠᨨ 盐ᆠᨨ ᆠ � 鼀� �ᆠ � ur r ur F = I l ´ B㡰 = I lB 矄� q ᨨ ᨨᆠᆠ� �ᨨ h犨�hᆠ  ᔼ h�矄ᆠ矄q㦨҈ \ F㦨IlB矄� ҈ 㦨 졠 ᆠAC 盐ᨨᆠ盐 hᆠ  ur m I  B  ᨨ ACB㦨  p r҈

 �ᆠ�ᨨ ᨨ  �矄 鼀� �ᆠ � ᨨ  泐矄鼀矄�鼀  ᨨ AC犨� � � \ q = ҈° ÞF㦨 졠 矄�鼀 CD m I 㝐� �ᆠ �  �矄 ᆠx 盐ᨨᆠ 犨�B㦨  px

r㦨҈鼀 D

dx

D

O



r҈㦨鼀

x

C

B

ᨨᆠᨨ 矄鼀矄�鼀  dx �矄 r ᨨ鼀O dF㦨I dxB

m I �m  I dx 㦨 p x p x 졠  � �� �

㦨҈맔dx맔

d d QwBR  \ T҈맔 - T ´ =    Þ T҈T㦨

mg ù é êëQ T =  úû

Qw鼀 BR  T = T +  d

\ w鼀 㦨

T 

ᨨ B㦨

\ q鼀 㦨 Q 

盐 鼀 �鼀盐鼀 矄�ᨨ ᨨ├� � 矄�ᨨ 㦨 \

\ ᔼw㦨NABQ Þ w㦨

mg QwBR  +  d

 ���㡰

\ F㦨

�m I p

r

òr҈

dx x

\ F㦨

� m I [ ᨨ� e x ] rr҈ p

WWW.JEEBOOKS.IN

PS-239

Moving Charges and Magnetism

� m I �m ´ ҈ r æ ҈ ö ᨨ� e  =  ᨨ� e ç è  ÷ø p p r҈ 㦨҈맔҈ � 犨 矄㡰 泐 鼀� �  盐㡰 ur  㡰 㝐� �ᆠ �  B㡰  ᨨ��� 㦨鼀� �ᆠ �  盐ᨨ 矄鼀�ᆠ�ᆠKLM졔鼀� �ᆠ �  盐ᨨᨨ 矄鼀�ᆠ�ᆠKNM ur m I m I \ B =  -�$㡰 +  $ 㡰 R R ᲼Q⧤㝐�矄�  y㜠z  ⧤㝐�  x㜠z 桌 ur m I m I m I ᨨ B = -  $� +  $ =  -$� + $ 㡰 R R R \ 㝐� �ᆠ ᨨᆠ ᆠ� � ᨨ   �ᆠ ur r ur m Iü ì F = q v ´ B㡰 = q í - v �$㡰 ´ -$� + $ 㡰 ´  ý R þ î \ F㦨

-m  qv I $ k ᨨ F㦨 R ur ur ur 㡰 F KLM = F KNM = F KM ur  F KM = BI  R㡰$� =  BIR�$

ur

ur

M 

㡰 I

y v  x

N �㡰 ᔴ盐  I  ᨨ盐�    ᆠ MN   矄��  犨� NM 矄盐鼀� �ᆠ �   ᆠ P

 ᆠ �  �ᆠ �矄 ᆠ  盐ᨨ  泐  鼀� �ᆠ ᨨᆠ 盐 ᨨ  矄 � 矄  鼀� �ᆠ ᨨᆠ ᨨ 盐ᆠ矄 

� 矄  ᨨ盐矄 ᆠᆠ�ᨨ  �    ᆠ �  �ᆠ � 盐ᨨᆠ MN ҈ m I B҈㦨 ᨨ盐犨 矄  a ҈ m I m I ᨨ B҈㦨 ᨨ盐犨 矄㦨 ᨨ盐犨 矄 a a

҈ m  I ˆ r k B҈ 㦨 a �  盐ᨨ矄�� 犨�NM m I 矄�  졔矄�  㡰犨 r㦨aᆠᨨ矄 B㦨  pr m I ᨨ B㦨 矄�  㡰 p a ᆠᨨ矄° m I ´  � 犨 矄㡰 ᨨ B㦨  pa 䰘 m I ˆ r k ᨨ B 㦨  a r r r \ Bnet 㦨 B҈ + B ᨨ

҈҈ m  I ˆ r k Bnet 㦨  a r v 㦨vᆠᨨ矄  �ˆ 졔v矄�   ˆ

v ˆ r v  v 㦨 �ˆ +   \ 㝐� �ᆠ ᨨᆠ r ҈҈m IQv ˆ r r   �ˆ㡰 \ Fm 㦨 Q v ´ Bnet 㡰 㦨 a r Fm r \ 꾀ᆠᆠ�ᨨ 鼀矄矄 a 㦨 m m IQv ҈҈ r  ( ˆ  �ˆ ) ᨨ a 㦨 ma ��㡰 ᨨᆠ   ᨨ⼄盐 ᨨ    ᨨᨨ r ᔼ 盐 � ᨨ鼀鼀� �ᆠ �  B = B�ˆ  ᨨᆠᨨ ᆠ盐 ᨨᨨ�矄 ᨨ r r

ᨨ⼄盐ᨨ ᨨᨨ㦨 M ´ B r M = IA㡰 kˆ ᨨ

pa  a   矄� ҈ ᨨ꾀㦨҈a   r r \ M 㦨 ҈Ia㡰 kˆ B = B�ˆ r r r r \ t 㦨 M ´ B ᨨ t 㦨 ҈IaB㡰 kˆ ´ �ˆ 㡰 r ᨨ t 㦨 ҈Ia  B 㡰 ˆ  �㡰 㝐� �ᆠ �  盐ᨨᆠ盐 � 犨�PR m  I p m  ´ � Ҙ ´ = ´ 㦨 ҈㦨 p p rPR p � ᲼�     ᨨ  ᨨ犨 犨 矄桌 ᨨ A㦨

 ᨨ F҈ = F  = BIR�$ r r r r \ ᨨ ᨨᆠᨨ  ᨨᨨ F = F҈ + F Þ F 㦨BIR �ˆ

a v  졔Q r  a P

ᨨ

�꾀 맔 

ᔼ꾀 맔 턼

�  v㦨҈ 鼀⏌矄 졔

鼀  㦨�鼀

和�鼀�泐 鼀� �ᆠ �  盐ᨨᆠ盐 � 犨�QR Ҙ  ´ I Ҙ I ᲼�   ᨨ  ᨨ犨 犨 矄桌 = 㦨  ´ p  p

ᨨ鼀� �ᆠ � R᲼ 盐ᨨP Q桌 Ҙ  Ҙ Ҙ + I =  ҈ + I 㡰 B 㦨B҈졔B㦨 p  p p ᲼�     ᨨ  ᨨ犨 犨 矄桌 ᨨᆠ  � ᆠ  泐   ᆠᨨ

F 㦨qvB矄� q Ҙ 㦨pvB矄� 黨 㦨҈맔҈҈黨맔맔҈�맔 ҈졔I㡰 p \ 맔҈㦨҈맔҈҈黨맔맔҈�맔҈䰘 ҈졔I㡰 ᨨ I㦨꾀 ��㡰 ᨨ  � Rᨨ ᨨ鼀� �ᆠ �  盐ᨨ � 犨�ᆠ泐� �ᆠ盐 ᨨ �꾀矄 ᨨ盐  B㦨҈䰘 I졔҈㡰㦨�맔҈䰘

r  �矄 ᆠᨨ  �矄犨� ᨨ鼀 m  ´ � ´ ᨨ r㦨҈鼀 \ �맔҈䰘㦨 p r �.e. �    ᨨ ��  ҈鼀 ᨨ鼀  �ᆠ�ᨨ  ᨨ ᆠ盐  ᨨ盐犨 矄   � 犨 矄 矄ᆠ�泐

WWW.JEEBOOKS.IN

EBD_8341 PS-240

Physics

Magnetism and Matter

19

Topic-1 : Magnetism, Gaus's Law, Magnetic Moment, Properties of Magnet ҈





ᆠ㡰  q = ° t㦨҈㜠鼀B㦨

ᨨ⼄盐ᨨ 鼀�  t = MB 矄� q ҈ = M ´  ´ 矄� ° ҈ Þ ҈ = M ´  ´ Þ M = 꾀㜠鼀   ᨨ矄��ᨨ ᨨ 矄⼄盐���盐鼀 q㦨 㡰 ᨨ矄��ᨨ ᨨ 盐 矄⼄盐���盐鼀 q㦨҈ 㡰 㝐� �鼀盐鼀犨ᨨ├⼄盐� ᨨᨨ鼀�  ᨨ鼀矄 ᨨ盐 矄⼄盐���盐鼀 DU = U f - U � = -MB ᆠᨨ矄҈° - - MB ᆠᨨ矄°㡰 W = MB =  ´  ´  \ W = 䰘 ´ ҈-  㡰 ෌�  㝐ᨨ鼀 ᨨ � �ᨨ ᆠ�ᆠ盐ᆠᨨ�I㦨├�鼀 㝐� �ᆠ鼀ᨨ鼀 ᨨ ᆠ�ᆠ盐ᆠᨨ�M㦨꾀鼀 ᨨ�ᨨ ├� �ᆠ �泐ᨨ ᆠ�ᆠ盐ᆠᨨ� ҈  ⧤쟼 = I w  w㦨 �盐矄 ᨨ ᆠᨨ� ᨨ � �泐ᨨ 鼀� 㦨MBᆠᨨ矄f ᨨ鼀 �泐ᆠᨨ 矄�ᨨ

҈  I w = U � - U f = - MB ᆠᨨ矄 ° - - MB 㡰  MB ҈  Þ = Iw    ´  ҈ Þ = 㡰w     Þ ҈ = w Þ w = ҈ 

b㡰 B҈ =



�



䰘

 黨

µ  K  p ( d ⏌  )

҈

  B =

꾀 �盐鼀ᨨ鼀 盐鼀L㦨Iw㦨 mR㡰w

µ M p ( d ⏌  )  µ M p ( d ⏌ ) 

B = 㦨҈ \  q = B҈ µ M p ( d ⏌ )  ᨨ q㦨�º

uur

矄盐  � �矄�º ᨨ鼀҈  �犨  B uur   v  ᨨ矄ᨨ ᨨᆠᨨ  �ᆠ�矄 ᨨ ᆠ㡰 ␔ᨨ├ ᨨ ␔㦨鼀· 㦨맔҈맔҈ᆠᨨ矄 ҈�㡰㦨 b㡰 ␔├ ᨨ犨 鼀� �ᆠ �ᨨ鼀ᨨ鼀  㝐 = �꾀 ᆠᨨ矄 θ � 㝐 µ ᆠᨨ矄θ ␔  犨ᨨ鼀� �ᆠ � 矄� ᆠ�    �ᨨ 䰘�  ⼄盐���盐鼀犨� 矄ᨨ ҈ ᆠᨨ矄 θ 㦨 ᆠᨨ矄 䰘� 㜠  㡰 㦨 ᆠᨨ矄 � 㦨  ҈� 㦨 \ » ҈҈   r N�A ᆠ㡰 M 鼀�鼀ᨨ鼀 ⏌ᨨ盐鼀㡰㦨 Al N� �㡰҈� 㦨 㦨 㦨꾀鼀 꾀鼀҈ l � ´ ҈  uur ur 㡰 ᨨ � �泐 U㦨 - M  B 㦨MBᆠᨨ矄q ᔼ ᆠ矄ᔼ q 㦨҈ U㦨졔MB ᔼ ᆠ矄ᔼᔼ q 㦨黨 U㦨 ᔼ ᆠ矄ᔼᔼᔼ q 㦨ᆠ盐U 㦨졔 矄矄  졔MB㡰 ᔼ ᆠ矄ᔼ q 㦨ᨨ盐矄U㦨 \ ᔼ>ᔼᔼᔼ>ᔼᔼ>ᔼ 㡰 㝐� �ᆠ� 矄ᨨ  ᨨᆠ ᨨ鼀ᆠᨨ矄 ᨨᨨ矄 ᔼ 矄�  鼀�  矄 �ᆠ  ᨨ鼀矄ᨨ盐 ᨨ ᨨ ᨨ ᨨ盐矄�  鼀�  ᨨ鼀 ᨨ ᨨ矄ᨨ盐  ᆠ㡰  �盐鼀ᨨ鼀 盐鼀ᨨ  �ᆠ L㦨mvr㦨mrw犨 w㦨pn ᲼Qv㦨rw桌 q wq w \ ⼄盐 ᆠ泐n㦨 錐  盐 �㦨 㦨q 맔n㦨 t p p wq qr  w ´ pr  Þ M㦨 㝐� �ᆠ鼀ᨨ鼀 M㦨�A㦨 p  M q wqr  \ = = L  mr  w  m qw æ wö q 㡰 ᔴ盐 �㦨 㦨 ⼄盐 ᆠ泐㡰 ᆠ �㡰㦨 çè ÷ø q㡰 =  p p t 㝐� �ᆠ鼀ᨨ鼀  æ qw ö   w M㦨 �㡰 A㡰㦨 çè ÷ø pR 㡰 = qwR 㡰 p

M qw R  q R R = =  L  mR 㡰 w m (q,m) (q,m) ᆠ㡰 ᔼ 盐 � ᨨ鼀鼀� �ᆠ � 鼀� �ᆠ ᨨᆠᨨ ᆠ盐  ᆠ泐� �ᨨᨨ�矄 ᨨ 鼀� �ᆠ � �矄 �ᆠ盐ᨨ   ᨨ  盐矄ᆠᨨ 矄� 犨ᨨ �鼀�ᆠ泐ᨨᨨ矄� 鼀 矄泐 鼀� �Ἐ矄   盐ᨨ 鼀 AB ᨨᆠ dF 㦨 I ( d l ) B 矄� 黨° = I ( d l ) B   犨 矄㡰

\

҈҈

WWW.JEEBOOKS.IN

PS-241

Magnetism and Matter X

X

X

X

dF X

X

B A

X

X

X

X

X

ᔴX

l X

X

X

l

D

X

X

X

dF

X

X

X

X

X

X

ᨨᆠᨨ ADFAD㦨IdlB҈矄� 黨 IdlB҈ B҈ D

d

ᔼ X

҈

҈

҈

҈�

X

X

X

졠 鼀 CD ᨨᆠ dF 㦨I dl㡰B ᲼ �� ᨨ   ᨨ 桌

矄犨ᨨ ᨨᆠ矄犨�ᆠ ᆠᨨ盐 和�鼀�泐 ᨨᆠ矄ᆠ� �ᨨ   �鼀�ᆠ泐ᨨᨨ矄� 鼀 矄犨�ᆠ ᆠᨨ盐� � ᆠ   ᨨᆠᆠ� � ᨨ  ᨨᨨ犨� ᨨ ur B 㡰  ᨨᆠᨨ  ᨨ ᨨ㦨 mB҈ ur

 ᨨᆠᨨ 矄ᨨ盐 ᨨ㦨 mB  N 和� ᆠ 犨ᨨᨨ矄ᨨ  鼀� �ᆠ

 犨�ᆠ 盐ᨨ 泐 S �   ᨨᆠ矄�  �   �ᆠ�ᨨ 矄  ᨨ  鼀� �ᆠ   � ᆠ矄 ᨨᆠ矄犨矄ᨨ⼄盐 q ne � 㦨 = 㦨ve㦨҈҈맔҈맔҈҈黨㦨҈맔҈꾀 t t 㝐� �ᆠ鼀ᨨ鼀  M㦨�맔A㦨�맔pr 㦨҈맔҈맔҈맔�맔҈҈맔�맔҈҈ 㦨҈�맔҈꾀鼀 ␔�ᨨ  � L�矄 �   ᨨ鼀ᨨ ᆠ�ᆠ \ �鼀ᨨ  ᆠ�ᆠ㦨 � ᨨ 犨� L Þ pr 㦨L Þ r㦨 p pL L \ 꾀ᨨ  ᆠ�ᆠ㦨pr㦨  = p p 㝐� �ᆠ鼀ᨨ鼀 ᨨ ᨨᨨ� 犨 �ᆠ ᆠ盐 � ᨨ犨矄 �L ᨨ M㦨�A㦨  p ᆠ㡰 ᨨᆠᨨ AB 鼀� �ᆠ �  盐ᨨᆠ盐 I҈�矄ᨨ � AB \ F㦨IdlB矄� qAB 㦨I d l ´ B ´ 矄� °㡰 =  C B

I

O

O' I҈ A

D

ᨨᆠᨨ CD和�鼀�泐 鼀� �ᆠ �  盐ᨨᆠ盐 I҈�矄 ᨨ �DCᆠ盐矄q㦨҈    ᨨ ᨨᆠᨨ DC�矄 ᨨ ᔴ㦨IdlB矄� q㦨Idl矄� ҈ 㦨 ᨨᆠᨨ BC ᔴᨨ 矄� 矄鼀鼀 dl B҈

I

C

B

FBC㦨IdlB҈矄� 黨 Þ dF㦨IdlB҈ 泐 鼀� �Ἐ矄   盐  �ᆠ�ᨨ ᨨ  �矄 ᨨᆠ�矄  �ᆠ盐ᨨ  ᨨ   �ᆠ ᨨ盐犨 矄

I A 泐 鼀� �Ἐ矄   盐  �ᆠ�ᨨ ᨨ  �矄 ᨨᆠ�矄  �ᆠ盐ᨨ  ᨨ  �ᆠ � 犨 矄和� ᆠ  ᆠ盐 鼀 矄ᨨᆠ 矄泐鼀鼀�ᆠᨨᆠ盐  I҈  ᨨ ᨨᆠᨨ BC犨�ᆠ ᆠᨨ盐  ᆠᨨ  ᨨᆠᨨ AD  ᆠ  ᨨᆠᨨ ᨨᨨABCDF 㦨

 ᨨᆠᨨ BC AD犨�ᆠᨨ⼄盐ᨨ ABCD� ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ ᨨ盐OOἘ �矄矄矄 泐 ᨨ矄O ҈ ᆠ 㡰 졠 泐� 盐ᆠ ᆠ�ᆠ �  鼀� ᨨ矄�ᆠ �  ᨨ鼀 ᆠᨨ矄 ᨨᨨ矄ᨨ  � � 矄 ur ҈䰘 㡰 꾀矄 鼀� �ᆠ �  B �矄 �ᆠ   �ᨨ � ᨨ x㜠 �矄� xy ᆠᨨ鼀ᨨ  矄ᨨ  鼀� �ᆠ � Bx㦨Bᆠᨨ矄� 㦨 B ⏌   By㦨B矄� � 㦨 B ⏌  Iᨨ

S

Y

R B

t

A



�

P

X

Q

和ᨨ� ᆠᨨ ᨨ鼀 ur uur æ B ö $æ B ö B = �$ ç + ç M = �A㡰kˆ = I  L k$  ÷ ÷ è ø è ø

 ᨨᨨ⼄盐ᆠ� �ᨨ  ᨨᨨ r uur ur æ B $ B �+ t = M ´ B = I  L k$ ´ ç è  

 $ ö = I  L B ( ˆ - �ˆ) ÷ø 

I  L B  �矄 �ᆠ ᨨ �� QS ᨨ鼀QᨨS

㡰  ᨨ⼄盐�矄�  ˆ  �ˆ  �ᆠ�ᨨ �.e.ᨨ턼和  ᆠ ᨨᨨ犨�ᨨᨨ盐  �矄矄矄� � ᨨ盐� 턼  和꾀ᆠᆠᨨ � � ᨨ  ᨨ鼀ᨨ  �ᆠ盐  矄鼀ᨨ鼀 ᨨ � �ᨨ   鼀ᨨ盐 QS ҈ ҈ æ  ö   IQS㦨 I z = çè ML ÷ø = ML     꾀矄ᨨᨨ⼄盐t㦨Ia

t I  L B ´   I  B = = I  M ML a�矄ᆠᨨ 矄   ᨨ ᨨ鼀

\ a㦨

҈ q = w t + a t   w㦨  ҈  ҈ æ I  B ö Dt 㡰  \ q = a t = çè    M ÷ø

ᨨ

q=

 IB Dt 㡰   M

WWW.JEEBOOKS.IN

EBD_8341 PS-242

҈

Physics

�㡰㝐� �ᆠ鼀ᨨ鼀 M㦨IA 犨  I ᆠ盐  盐 ᨨᨨ� 鼀ᨨ�ᨨ  ᨨ ᆠᨨ   A㦨ᨨ ᨨᨨ鼀 泐ᆠᨨ  M㦨IA㦨



w e㜠

R



҈黨







  I ´  =  ´  Þ I  = = 䰘� 꾀⏌鼀    b㡰 ␔   鼀� �ᆠ �  �矄 �  ᨨ  �鼀� �ᆠ 矄盐矄 ᆠ�ᨨ 盐ᆠ矄鼀� �ᆠ � � ᨨᨨ矄� �ᆠ�ᨨ

矄ᨨ 鼀� �ᆠ � � 矄�  ᆠ�泐ᨨ 矄 犨� ᨨ 和ᨨ �  � 矄�    鼀� �ᆠ 矄盐矄 ᆠ ├ � 矄�  ᆠ�泐�矄 ᨨ 㡰 鼀  鼀� 矄 P㡰鼀 ᨨ 鼀�矄犨� �  ��泐 �ᆠᨨᆠ��泐  矄 ᨨ鼀ᆠᨨ矄 T㡰 鼀 ᨨ 鼀�矄犨� ᨨ犨 ��泐 ᨨ犨ᆠᨨᆠ��泐 Þ





�





㡰 꾀ᆠᆠᨨ � �ᨨᔴ盐�犨 ᨨ鼀� �ᆠ矄盐矄 ᆠ



Þ

҈ 㦨�䰘꾀㜠鼀 � ෌� l㦨�ᆠ鼀㡰

m㦨

㦨pm맔B맔矄�  㦨҈맔�맔

 

c㦨 䰘



 ´ � ´҈  㦨맔҈ 

㡰 㝐� �ᆠ矄盐矄ᆠ���泐 c=

ᔼ 

犨  ᔼ =

Topic-2 : The Earth Magnetism, Magnetic Materials and their Properties b㡰 ෌�  ᨨ盐鼀ᨨ �ᨨ ᨨ  V = ҈- 鼀 �鼀��泐 m r = ҈ 盐鼀ᨨ 盐 矄盐 � � n㦨҈ 㝐� �ᆠ鼀ᨨ鼀 ᨨ  �ᨨ ᆠᨨ矄ᨨ ᨨ� 



 ´ ҈   㦨 c �

ᨨ⼄盐 盐ᨨ  ᨨᆠ㦨F맔҈

 ᨨ⼄盐���盐鼀F맔҈㦨҈맔�맔  Þ F㦨�黨 ᔼ   ᨨᆠ �矄鼀ᨨ    ᨨ⼄盐 盐ᨨ鼀� �ᆠ � 犨�鼀ᨨ 鼀� ᔼ犨�矄ᨨ矄ᆠ�� �ᨨ盐 鼀

r r ᨨ矄��ᨨ 犨   �犨  pm   B �矄 ᨨ

c

҈

c µ Þ ҈ 㦨

c ᔴ҈ ᔴ

ᨨ⼄盐 盐ᨨ鼀� �ᆠ �

҈

҈ ´ � ´ ҈ - = 黨黨� » � ҈ - 㡰 ᨨ鼀� �ᆠ鼀�꾀ᆠᆠᨨ � �ᨨᆠ盐�矄犨 ҈ cµ T ᨨ犨ᨨ鼀盐矄T҈ T c҈T҈ = cT I 盐 c = B I I \ ҈ T҈ =  T B҈ B





P㦨m맔l㦨҈

V N Þ M = mr - ҈㡰 ´ �V l l

Þ M = 黨黨黨 ´

nh nh Þ Rw㦨 QV㦨Rw㡰  pm p e nh nhe eh = = \M㦨 ´ Q n㦨҈ ᨨ�ᨨ盐 矄㡰  pm pm pm �ᆠ�ᨨ ᨨ 鼀� �ᆠ鼀ᨨ鼀 盐鼀m �ᆠ盐ᨨ   ᨨ ᨨ�  B nˆ ��㡰 ␔├ ᨨ犨 ᨨ⼄盐 t ᨨ  r r r Þt㦨MB矄� q t = M ´B 犨 q�矄  �犨 M B q㦨 he heB e ´ B 矄� ° = \ t㦨MB矄� q㦨 pm pm �ᆠ�ᨨ ᨨ ᨨ⼄盐ᆠ  ᨨ盐 泐��    盐鼀盐

 �ᆠ�ᨨ ᨨ ᨨ⼄盐�矄 �ᆠ盐ᨨᨨ 㝐 

Þ mRw㦨



Þ M = mr - ҈㡰 ´ N�

eö e ew æ ´ pR   Þ M㦨 ´ pR  çQ҈ = ÷ è sø p T

҈  \ M㦨 ewR  盐ᆠᆠᨨ � �ᨨᨨ Ἐ矄 ᨨ泐 mvx㦨nh⏌p



M = m r - ҈㡰 ´ N�A

㝐� �ᆠ 鼀ᨨ鼀   ´҈ 㦨⏌鼀 =  ᨨ盐鼀 ҈

 ҈ = ´҈ =  ´҈ ´҈   ö æ b㡰 ᔴᨨᆠ��泐  = m    = m  � çè = ÷ø l 

ᨨ犨 c =



ᨨ㦨

 ҈ � 㦨 맔�㦨꾀⏌鼀 l 

WWW.JEEBOOKS.IN

PS-243

Magnetism and Matter

黨

҈ ҈҈ ҈

҈ ҈

҈�

b㡰 ෌� 盐鼀ᨨ 盐 矄

㦨҈盐 矄⏌ᆠ鼀㦨҈맔҈盐 矄⏌鼀 ᔴᨨᆠ��泐ᨨ  ᨨ鼀� 㦨҈꾀⏌鼀 ᔴ盐 ᨨ 鼀� �矄  ᨨ鼀� ᔼ㦨䁸 矄� � 㦨 ᔼ ᨨ 100 = 10�맔ᔼ ҈ \ ᔼ = � = ҈ 鼀꾀 ҈ b㡰 ෌ ᲼꾀桌�矄 ᨨ鼀�盐矄  ᨨ鼀├� �鼀   鼀� 矄 �� ᆠᨨᆠ��泐㡰 ෌ ᲼桌�矄 ᨨ鼀├� �ᆠᨨ鼀� 矄  矄 ᨨ鼀矄 㡰 㦨l㦨맔�맔҈�ᆠᨨ矄 q㡰맔�㦨䰘鼀 泐��   盐 ᆠ �鼀ᨨ矄ᨨ  ᨨ �ᨨ ᆠ㡰 㝐� �ᆠ � � 矄ᨨ ᨨ� B㦨mn� B = n�  ␔ n㦨 盐鼀ᨨ 盐 矄盐 � � 㡰 Þ m B N� ҈� = Þ  ´ ҈ = Þ m L ҈ ´ ҈- Þ �㦨꾀 b㡰 �鼀� �ᆠ鼀�矄    �       鼀� �ᆠ �  B矄 矄 �鼀� �ᆠ鼀�矄 㡰 ᔼ 鼀� �ᆠ �ᨨ ҈ ᨨᆠ µ  ᔼ  �� ⼄盐矄�ᨨ  ᨨᆠµ 

 ᆠ 㦨 b㡰 ෌� M҈㦨҈Am  M㦨҈Am錐 r =

 cm = ҈鼀 

 㦨҈졔졔

Bnet =

҈

 ҈  졠

和 

-䰘

҈ ҈ + ҈㡰 ҈㡰

TµI \



ᨨ







҈ ⏌ 鼀  㝐 ᔴ泐 㦨 ᆠ ᆠ㡰 ෌� 㝐� �ᆠ鼀ᨨ鼀 M㦨䰘맔҈Am 㝐� �ᆠ � 㦨҈T 㝐ᨨ鼀 ᨨ � �I㦨䰘�맔҈⧤�鼀

矄� � T = p

I MB

䰘� ´ ҈-

p ´ ҈ s 䰘 ´ ҈ ´ ҈ ҈

�鼀├  ᨨ҈ᆠᨨ鼀ᨨ矄ᆠ��ᨨ 矄 t㦨҈T㦨p맔҈ 㦨� » �矄 = p

-

=

Topic-4 : Miscellaneous Problems ҈



T

B  æ ö ´ çè ÷ø = B҈   B҈ 黨 \ B = = 0.46    㡰 矄� ��鼀⏌ᨨ矄ᆠ��ᨨ �ᨨ 

ᆠ㦨p



X

B ᆠᨨ矄 �° B ´  æ ö = çè ÷ø = ҈� B҈ ᆠᨨ矄 °  ´ B҈ ´ 

鼀 

㦨p ( 㝐)

+  ´ ҈ -� = � ´ ҈ - 犨⏌鼀

꾀 �矄ᨨ ᨨ�ᨨ

Bx҈

ᔼ 㝐 ␔ 㝐㦨鼀� �ᆠ鼀ᨨ鼀 ᔼ鼀ᨨ鼀 ᨨ � � 㦨 鼀� �ᆠ �



MR   = MR   

Bx 

㦨 p

㡰 ෌� 㝐㦨맔҈꾀鼀 㦨 㦨맔҈鼀 m 㝐 쟼 矄鼀� �ᆠ � 㦨   p  p ´ ҈ -䰘  ´  ´ ҈ = ´ @  ෌盐矄矄 p  ´ ҈ 㡰

I  = MR  +

T

=





㡰 I҈ I 鼀ᨨ鼀 ᨨ � ��  �矄 矄ᆠᨨ ᆠ矄 矄ᆠ�泐 I҈ =  MR 

I҈ = I



Topic-3 : Magnetic Equipment ҈

T҈

I mgd

MR   =   MR   I ␔ T㦨 p MB x

T҈ = T

ᨨ 盐矄㡰 \



r

r

m M҈ + M  㡰 =  + BH p r

�鼀�ᨨ  T = p

㡰 ᔼ�矄ᆠ ᨨ鼀 �� �  犨� � ᆠ矄ᨨ   鼀� �盐  ᨨ  鼀� �ᆠ �  B㡰   ᆠ��ᆠ 鼀盐TC B㡰 ᆠ矄矄 ᔼ  B > B҈    ᨨ    鼀盐  犨 �ᆠ    矄�矄 ᆠᆠᨨ鼀矄 ᨨ矄 ᨨ盐 矄矄 b㡰 ෌� 㦨TC㦨҈⧤  㦨䰘�TTC㦨䰘�⧤ ␔� � ᆠ矄� TC ᆠ矄矄 \꾀㦨�TTC矄 ᨨ盐 犨 䰘�⧤ ҈⧤

WWW.JEEBOOKS.IN

EBD_8341 PS-244

Physics

Electromagnetic Induction

20

Topic-1 : Magnetic Flux, Faraday's and Lenz's Law ҈



b㡰 ᔴ矄 㡰␔  鼀� �矄 � �犨� ᆠᨨ 矄  矄  盐  f㡰 犨� ᆠ  �     鼀  �矄 � 盐ᆠ  矄ᨨ � ᨨ鼀 犨�  ᆠ �  ᨨ矄�� �ᆠ�ᨨ  ᔴ矄 b㡰␔  鼀� �矄ᆠᨨ鼀泐� 矄�  盐  f㡰犨�

ᨨ ᆠ  � 矄ᨨ � ᨨ鼀 犨� 矄 ᨨ犨 盐  ᆠ�ᨨ  ᔴ矄 ᆠ㡰␔  鼀� �矄鼀├� �ᨨ  ���  盐  f㡰 犨� ᆠ  �     鼀  �矄 � 盐ᆠ  �  ᨨᨨ矄� �ᆠ�ᨨ

矄ᨨ � ᨨ鼀 犨�  ᆠ �  �� �ᆠ�ᨨ  � 矄 �ᆠ�ᨨ  㡰 꾀矄犨├ ᨨ犨鼀  e = NABw ᆠᨨ矄 wt N㦨҈ 꾀� ᨨ犨

�

㡰 꾀矄 鼀� �ᆠ � � 矄 ᨨ鼀 ᆠᨨ矄ᨨᨨ  ᆠ泐 鼀� �ᆠ � � ᆠ� �鼀� �ᆠ 盐  ᨨ盐�  �

 ��ᨨ  f�㡰 鼀盐矄  矄矄� �  ᨨ盐�    ᨨ盐 ��ᨨ  和� ᆠ 盐  �  犨ᨨ ��ᨨ 矄  �  ᨨᨨ矄� ��ᨨ  \ f�㦨f



㡰 꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ  I t㡰㦨It ҈t㡰 \ I㦨ᔼIt f=B.A f㦨 m nI㡰맔 p 㡰

Q B = m ᔼ and A = pR  㡰  f VR = dt VR = m npR  I  I t 㡰

A B w æ ҈ö A B  w  ᆠᨨ矄 wt e > 㦨 < > 㦨 çè ÷ø R  R R

 ᨨ�ᨨ犨ᨨ矄矄�  ᨨᨨ 盐ᨨᨨ盐 � � 





=
㦨





҈ s  b㡰 ␔ �� �鼀�ᨨ T㦨҈矄 p p = \ 꾀 �盐 ᨨᆠ�泐 w = ҈ � 㝐� �ᆠ 盐 f 㡰㦨BAᆠᨨ矄wt d f = BAw 矄� wt = BAw 矄� ( wt ) 쟼鼀 � 盐ᆠ  E = dt p ᔼ 盐ᆠ 鼀 e �矄鼀 �鼀盐鼀犨  wt㦨  p Þ t = = � 矄  p � ᨨ� 盐ᆠ 鼀 ᨨ鼀� �鼀盐鼀� ᨨ p wt = p Þ t = = � s p � \ᔼ 盐ᆠ 鼀 �矄 ᨨ㦨�矄 㡰 Q㦨BA 㦨 mn�㡰A 㦨m n kt eat㡰A d dQ -a t e= = -m  nAk te 㡰 dt dt Þ VR =   t =



䰘



= -m nAk᲼t -҈㡰e- at + e -at ´҈桌

꾀A㦨ᨨ  X ᨨ D㦨 ҈맔맔꾀ᨨ � �㡰ᆠ鼀

҈ æ ö = ç    ´ ´  ´  ÷ ᆠ鼀  㦨�맔҈鼀  è ø dB \ e� 盐ᆠ = A = � ´ ҈ ´ ҈ = � ´ ҈ V = �mV dt

黨

= - m nAk ᲼e -at ҈ - t 㡰桌 e - m nAk -at �= = ᲼e ҈ - t 㡰桌 R R 꾀t㦨�Þ b㡰 꾀ᆠᆠᨨ � � ᨨ  泐矄 犨 ᨨ  ᆠᨨ鼀� �ᆠ - f � 盐ᆠ�ᨨ   =  � � ҈�  ´ = � Þ  ´ = � ᨨ  =   ҈ 

WWW.JEEBOOKS.IN

PS-245

Electromagnetic Induction ᔴ  � �     �泐ᨨ   � 盐ᆠ ᆠ ҈ ҈ � D쟼 =  �҈  �  = ´ ´ � ҈ 㡰    � = ´ �� = 䰘�   ᲼ᨨ 盐矄桌 ᆠ � 턼 = Df = ҈ 꾀  -  㡰 = ҈ ´ � ´ ҈ - � ҈ ҈

(

҈

҈

)

dq dt dq ҈ d f BA ҈ = \  Þ ò dq = ò d f \ q = dt R dt R R ҈黨 㡰 �鼀ᆠᨨ 矄  㦨 ᔴ ᔼ鼀  ᆠ㦨

҈ � ´҈- 㡰  - 㡰 㦨҈맔҈ ҈ ᨨ ᨨ�ᨨ  鼀ᆠ 矄 和ᨨ� 矄 ᨨ盐    ᨨ 盐矄 ҈҈ 㡰 꾀ᆠᆠᨨ � � ᨨ  泐Ἐ矄 犨 ᨨ  ᆠᨨ鼀� �ᆠ df � 盐ᆠ�ᨨ  e = dt 꾀矄ᨨe 㦨�R df Þ ò d f = R ò �dt \ �R = dt 㝐� �盐 ᨨ ᆠ  ��  盐  f㡰㦨R맔盐 ᆠ盐  矄 �鼀 � ҈ ҈ ᨨdf 㦨 ҈ ´ ´ ´ ҈ 㦨�␔   ҈ b㡰 쟼ᆠ�ᆠ 盐 �矄�� 泐 f㦨꾀

æ ҈ ö ÷ wC ø

 \ R ҈� 㦨 R + ç è

\ ᔴ㦨 

턼  㦨 㜠 ⏌ t 㡰

�㡰 ᨨᆠᨨ�C҈ᨨᨨ 盐 矄N҈㦨�  �盐矄r㦨҈ᆠ鼀 ᨨᆠᨨ�Cᨨᨨ 盐 矄N㦨  �盐矄R㦨ᆠ鼀

 d f æ m N  ö  d� æ m  N҈ N  pr ö =ç pr N҈ = ç ÷ ÷ ҈t - 㡰 dt è r ø dt è R ø 꾀t㦨҈矄

æ m N N pr  ö m  N҈ N  pr    e=ç  ҈  = ÷ R R è ø



 =

 p㡰҈ -䰘 ´  ҈ - ´ � ´ - p  ҈

 =  ´ p  ´ ҈-䰘 ´ ҈ ´ ҈ ´ ҈- -  =  ´ ҈ ᨨ㦨鼀㦨

҈

 Þ x = �

҈�㡰 B㦨맔҈� R㦨҈ᆠ鼀㦨҈鼀

p p = T  r r 盐 矄 盐 ᆠ�ᨨ ᨨ �鼀 f = B × A = AB ᆠᨨ矄 wt 㡰

㡰 꾀矄犨├ ᨨ犨㝐� �ᆠ 盐  f = B A

w=

m 㡰  ´ ҈ - 㡰 

҈䰘

  = ´ ҈ 鼀矄 \ ᔴ㦨鼀矄 w �

e=

㡰 꾀ᆠᆠᨨ � � ᨨ  泐矄 犨 ᨨ  ᆠᨨ鼀� �ᆠ � 盐ᆠ�ᨨ  Ld� ᔼ 盐ᆠ  鼀  e 㦨 dt æ � ö � ´ ҈ � � = L ç =  㦨 ҈䰘  ÷ Þ L = è ҈矄ᆠ ø   㡰 ᔼ 矄�  矄  � �矄 � 泐�쟼µ犨� ҈ �矄 ᆠ   ᨨ盐矄�  �矄 ᆠᆠᨨ � � ᨨ 쟼 µ   ᆠ   ��ᨨ  �矄 矄 ᨨ犨  泐ᆠ盐 㡰

´ p  ´ ҈ - 㡰  ᲼ 㡰 + ҈�㡰  桌 졠  矄ᨨ� � 㦨黨҈맔҈҈҈㦨黨맔҈҈҈犨 c I ҈ 㡰  鼀� �ᆠ �  �矄 a I � ᆠ矄� � �    ᨨ犨 犨 ҈ �ᆠ�ᨨ   ᨨ ᆠᆠᨨ � � ᨨ 矄犨 ᆠ盐 I҈犨� ᨨ犨�   �ᆠ�ᨨ  ab  I �   �ᆠ�ᨨ  dc



dI = ҈t - 㡰 dt æ m IN ö f矄鼀 = BA = ç   ÷ pr  㡰 è R ø ᔼ 盐ᆠ 鼀 � 矄鼀ᆠᨨ�

f  p  -  ⏌ t  =  t ¥  p     e  = ò = t

҈�



I = �t  - t + 㡰 Þ

ᔼ 盐ᆠ 쟼鼀  e =

҈

æ ҈ ö R + ç è wC ÷ø

෌� 㦨 R ҈�

=

҈

e ҈ df Þ �= R R dt

盐 � =

p æ ö ç 矄� -  ÷  è ø

f =  p   -  ⏌ t

b㡰 ᔴ盐  � 盐ᆠ  � =

-d f = ABw 矄� wt 㡰 dt 㝐 盐ᨨ 쟼鼀 㦨ABw㦨pRBw p = ҈ ´ ҈ ´ ҈ ´  ´ ҈-� ´  쟼鼀 � 盐ᆠ  e =

d b

ᆠ㡰 ᨨ�泐ᨨ 鼀 犨�ᨨᨨ矄�犨   鼀�  矄   矄   ᆠᨨ� 졠 泐�  ᆠ㡰 矄 ᨨ犨矄  矄 ᆠ ᆠ�矄�ᆠ

= ҈� ´ ҈-  = ҈� m 

҈㡰 ෌� dI㦨�㦨�꾀 dt㦨�鼀矄 ᔼ 盐ᆠ  ᨨ� E�nd㦨҈ 和 㜠� 盐ᆠ ᆠ㦨 䁸

WWW.JEEBOOKS.IN

EBD_8341 PS-246

Physics

L �  㡰 Df  Þ ҈ = Dt � ´҈- Þ㦨҈㦨҈鼀 ҈䰘�㡰

Dq =

矄� � E� =



Df L�҈  R R

 ��㡰 x = x

 Df = f f  f� =

ò

x =  x

µ I  µ I l ldx =   ᔼ (  ) p x p

和ᨨ ᨨ鼀쟼⼄ ��㡰ᆠ � ᨨ犨  ᨨ盐�  矄�矄 ᆠ盐ᨨ �鼀t㦨 犨  ᆠ盐 �҈�矄

Dq =

҈ é µ I  l ù ᔼ (  )  L�҈ ú ê R ë p û

� 㦨 �et⏌tL

L �  � = ҈  � = �҈ t = ( T  T ) = T  t L =  R 和盐矄�盐� �  矄 盐矄 � 㦨 �et⏌tL L T � = � e  T ⏌ L ⏌ R㡰 Þ t L = = R In  

盐  ᨨ盐�  ᨨᨨ꾀ᔴ쟼 꾀

r r ˆ ˆ + �├㡰 ˆ f = 꾀 = �ˆ + ├㡰 ��



�



Þf= 맔�㡰졔 맔�㡰㦨҈䰘�犨 ␔     矄ᨨ盐ᆠ�矄 矄犨�ᆠ   ᨨ    ᆠ盐    ᨨ ��  ᆠ矄矄 ᨨ ᨨ  � 盐ᆠ  ᆠ盐  ᨨᨨ矄矄   ᆠ盐矄 ᨨᆠ  �矄 Ἐ矄犨  ᨨ � 盐ᆠ ᆠ盐  犨� ᨨ鼀 ᨨ��  矄  ᆠᨨ� ᨨ 鼀 犨��矄 ├ 矄�ᨨ 泐�   ᨨ 㜠 盐 � ᨨ鼀鼀� �ᆠ � 꾀  ᨨ� 盐ᆠ 鼀 ᨨ ᨨ�

ᆠᨨ� 鼀� �ᆠ 盐  ᨨ盐�  ᆠᨨ�鼀盐矄 ᆠ  � 盐�  �矄 ᆠ矄鼀� �ᆠ 盐 � ├ 犨�  ᆠᨨ��矄 ᨨ ᆠ  �� � T盐犨   犨��矄� 鼀ᨨ�ᨨ  ᆠᨨ 矄 

 ᨨᆠ�泐�    �ᆠ�ᨨ  ᨨ  鼀ᨨ�ᨨ  꾀ᆠ � �ᆠ鼀ᨨ� �� 鼀� �ᆠ �  � ᆠ矄

r r ur  ᨨᆠ = ⼄ n ´ 㡰

䰘



 矄ᨨᆠ  ᆠᨨ   � ᆠ矄  ᨨᆠ     ᨨ ᆠᨨ 矄 犨� 鼀ᨨ ᨨ犨 矄 ᨨ   ᆠ� �  鼀 犨    犨ᨨ 矄 ᨨ  矄��  ᆠᨨ 犨� ᆠ㡰  ᔼ   ᆠ盐  �矄 ᆠᨨ 矄    鼀 � 盐ᆠ  �    ᨨᨨ ᨨ쟼鼀 犨�� 盐ᆠ �   I ᆠ�ᆠ盐犨�ᨨᨨ犨   盐  ᨨ盐�  � ᆠ  �矄 犨�  �鼀 ® Df B e=Dt ® 犨     ᆠ盐  �矄 ᆠᨨ 矄  B   盐 ᆠ  �� �  ᨨ盐�  � Circular 犨� ᨨ loop 꾀矄ᨨ �    ᆠ盐  ᆠ矄矄  矄 泐   鼀  � 盐ᆠ  �    ᨨᨨ �矄 ᨨ ␔     ᆠ盐  �矄 ᆠ矄� �   矄 泐      ᆠ  ��   盐  ᆠ矄� �� 犨 矄㡰ᨨ  ��   ᨨ  犨��矄⼄盐ᨨ ᆠ  ��  盐  ᆠ矄� �ᨨ盐犨 矄㡰 ᨨ     ᨨ  犨�矄盐ᆠ  Df ᨨ盐�  ᆠ�ᆠ盐 ᨨᨨ �矄 ᨨ d� df 㡰 ᨨ �   �ᨨ 鼀ᨨ � �   dt dt 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 矄ᆠᨨ  犨 df d�  �R  L =  dt dt df d� = �R + L  �㡰 ᨨ dt dt b㡰 쟼 矄矄�ᨨ  ᨨ  ᆠ � ᨨ盐� R ᨨ鼀t㦨ᨨ t㦨T

d f = �Rdt + Ld� ( ᨨ鼀 ⼄ ( � ) ) ᔼ �� � 犨 �

Df = R Dq + L�҈

黨

  �ᆠ�ᆠ盐� �矄 ᆠ  �  矄 �泐� ᆠ矄� � 盐 � ᨨ鼀 鼀� �ᆠ �  �ᆠ � ᨨ  ᨨ   ᨨ鼀 ᨨ� � 盐ᆠ 鼀 犨�ᨨ 盐ᆠ �  AEFD矄犨 矄�  ᆠ�ᆠ盐�EBCF矄盐ᆠ   ᆠ盐  ᨨ犨� ��   ᨨᨨᆠ矄鼀� �ᆠ� 矄ᨨ  ᨨᆠ�  盐犨  �ᆠ�ᨨ

ᨨ   ᨨ 㡰

 ᨨ   ᆠ盐  矄 ᨨ盐  ᨨ犨 �     �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  �  ᨨ    ᨨᨨ矄 ᔼ 盐ᆠ 鼀 � ᨨᨨ AEFD

df d dB = - BA = - A = -҈ ´ ҈ = -҈ dt dt dt ᔼ 盐ᆠ 鼀 �  ᨨᨨ EBCF df d dB = - BA Ἐ = - A Ἐ e㦨 㦨�맔҈㦨� dt dt dt 꾀泐� �盐 ᆠ�ᨨ 犨 F犨�ᆠ盐 �  ᆠ  FE �҈  �㡰 꾀泐� �⧤�ᆠ ᨨ 矄 犨 � ᨨᨨ EADFE ҈맔�҈҈맔�҈졔҈҈맔�҈҈ �҈�㡰㦨 Þ �҈�㦨҈  �㡰 꾀泐� �⧤�ᆠ ᨨ Ἐ矄 犨 �  ᨨᨨ EBCFE 졔��҈�졔҈�졔��҈ �҈�㡰㦨 �҈졔�㦨�  ��㡰 和ᨨ� �⼄ �㡰  ��㡰 䰘 A ҈҈�҈㦨� Þ �҈㦨�⏌҈҈ =   A 꾀矄ᨨ҈҈�㦨 Þ �㦨⏌҈҈A =  䰘  \ᔴ盐 � 矄�鼀  AE = �҈ = A 錐 BE = � = A   ҈ A  EF = �҈ - � 㡰 =  e= -

WWW.JEEBOOKS.IN

PS-247

Electromagnetic Induction 

҈

Ӹ矄 ␔     ᆠᨨ� A 鼀ᨨ矄 ᨨ犨 矄 B   盐鼀 ᨨ 鼀� �ᆠ � 矄 ᨨ  ᨨᆠ 矄矄� �  ᨨ盐�  B ᆠ  �矄

 ᨨ   � 盐ᆠ  鼀     ᆠ � 盐ᆠ  ᆠ盐  �矄 ᨨ 盐ᆠ  �  B

 �ᆠ�ᨨ  ᨨ ᆠ盐 � B犨�矄盐ᆠ 矄 ᨨ ᨨᨨ矄   � ᆠ  � �  B    ᨨ犨��   ᨨᨨ矄� �ᆠ�ᨨ ᨨ A

 �ᆠ�ᨨ  ᨨ  � 盐ᆠ  ᆠ盐  �    ᨨᨨ 矄 矄 ᨨ犨

ᨨ犨 꾀矄   ᆠ盐  � ᆠ矄矄   盐鼀 ᨨ  鼀� �ᆠ � 矄 ᨨ  ᨨᆠ 矄矄� �  ᨨ盐�    ᨨᨨ � ᆠ矄矄 �  ᨨ盐犨  �ᆠ�ᨨ  ᨨ ᨨᨨ矄  �矄 ᆠ  �   ᆠ盐  犨� ᨨ犨 �    ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  矄   Ἐ矄犨

F = -kx - �IB = -kx -

B I  ´v R 꾀ᨨ  矄矄�ᨨ  矄 ᨨ犨矄   � �矄 ᆠ矄 ᨨ  鼀 ᨨ矄ᆠ��ᨨ  矄ᨨ �矄 鼀�盐 ᆠ   ��  泐

F = -kx -

Þ A = A e

Þ t=

m I Þ f =  l dr pr

 䰘

V r



 �



m N  A L ᆠ㡰 ᨨᆠ ᨨ    矄� 犨   � �矄  矄ᆠ   ᨨ矄��ᨨ  x ᨨ鼀鼀  ᨨ矄��ᨨ  �矄

҈ 桌 



ᨨ犨�� ᆠ矄 ᨨ� 和ᨨ矄 � 盐ᆠ ᆠ犨�ᆠᨨ鼀�鼀矄 ᆠ㡰

㝐� �ᆠ鼀ᨨ鼀 㝐㦨ᔼ꾀 턼㦨r

dQ w p 㝐㦨 ᔼ맔꾀 ᔼ㦨

w r   x p x  dx 㦨 p l

e � ´҈- = ; ҈䰘0 m 꾀 R 

㡰 ᔼ 盐ᆠ ᆠ 㦨





µµ᲼矄㦨⏌Þµ

 ´  + ҈䰘 㦨 + ҈䰘 ;  W + 

ᔴ盐 �㦨

m ; 矄 k 矄ᨨ ⼄盐�  盐鼀 ᨨ  ᨨ矄ᆠ��ᨨ 矄 ҈ N= = �  㡰 ᔼ 盐ᆠ 鼀 e㦨vl 㦨맔҈맔�맔҈㦨҈�맔҈ ᆠ㡰 꾀矄ᨨ � ᨨ  犨�犨�鼀� ᆠᨨ 矄  㦨 㡰 㦨ᨨ盐 矄㡰   � ᨨ 犨� � �㦨 㡰

æ   ö 㦨m  ç ÷  è  ø

dr

e m  Ivl = × R p Rr b㡰 盐 ᨨ 鼀ᨨ�ᨨ  ᨨ  鼀�  ᨨ   �矄ᆠ    鼀ᨨ矄 ᨨ盐�  鼀� �ᆠ 盐  盐ᨨ犨 �ᆠ  쟼㝐 �矄 �   �        泐 ᆠ盐 矄  � 盐ᆠ 

矄ᆠ盐 矄矄盐ᆠ  �ᨨᨨ矄矄 �鼀ᨨ�ᨨ

矄ᨨ �矄ᆠ犨�ᨨ�  矄鼀 �ᆠ�ᨨ 矄  �ᆠ�ᨨ ᨨ 鼀� Ἐ矄 鼀ᨨ�ᨨ 

�矄 盐矄 �矄 ᆠ  꾀�ᨨἘ矄 �矄├      ᆠ 犨矄 �矄ᆠᨨ  �  ҈ 泐꾀�ᨨ b㡰 ᔼ 盐ᆠ  鼀  e㦨Bvl㦨҈맔҈맔�㦨�맔҈ 쟼⼄盐�  矄�矄 ᆠ R㦨

 ´ � ´ ҈- ´ ҈ ҈´ ҈

 㦨 �鼀ᨨ 犨�㡰 矄  � 盐ᆠ ᆠ 㦨 m 꾀l

ᔼ 盐ᆠᆠ盐  �  ᨨᨨ � =



=

A 桌 e

�鼀�ᨨ  T = p

m I pr 㝐� �ᆠ 盐  ᨨ矄鼀 �矄ᆠ鼀 dr, f = B × A = Bldr ᲼Q A = l dr B.A㦨BAᆠᨨ矄 桌

I

m

᲼矄  ⼄盐矄�ᨨ  A =

æ B I  ö çç R ÷÷ è ø ෌� m㦨�맔҈├� 㦨҈

l㦨҈鼀  㦨҈W ├㦨�

B=

d f m  Il dr = × dt  pr dt m  Ivl ×  Þ e = p r

bt m

bt

㡰 㝐� �ᆠ �  �矄 ᆠr ᨨ鼀 犨�

쟼鼀  e =

-

A Þ  = A e  m e

Topic-2 : Motional and Static EMI and Application of EMI ҈

BIv ´ IB  R

黨

l

r  Þ㝐㦨 l n p ò x dx 

p  㦨  nrl  b㡰 ᨨ鼀  泐矄 犨 ᨨ ᆠᨨ鼀� �ᆠ� 盐ᆠ�ᨨ  d f d BA㡰 d Bll 㡰 Bdl ´ l = = BVl e= = = dt lt dt dt

WWW.JEEBOOKS.IN

EBD_8341 PS-248

Physics ҈

B l V æ BV ö  l B 㡰 = 꾀矄ᨨ F = �lB = ç ÷ è R ø R 꾀⼄盐���盐鼀

®

B

l

BlV mgR 矄� q mg 矄� q = ÞV = R R B l  ҈

q

b㡰 ᔼ    ��  ⼄盐矄�ᨨ  ᔴ盐  ᨨ犨� � ᨨ盐�  犨�ᔼ㦨҈꾀

Speed of the frame, v = 10 ms҈ 和� ᨨ 矄⼄盐ᨨᨨl㦨҈ᆠ鼀 �矄 ᆠ ᨨ  矄⼄盐 鼀 ᨨ鼀 ᆠ盐  ᆠ泐� � 犨�矄 㦨҈ᆠ鼀 ␔ ᨨ � 鼀 � 盐ᆠ 㦨䁸 꾀ᆠᆠᨨ � � ᨨ�ᨨ㜠和矄 犨

=

҈҈

m  ᔼ 矄� q p´҈ 㦨 p  p

-䰘

´

҈´ ҈

҈䰘

(҈ )

µ I 矄� a + 矄� b㡰 pR 꾀泐� � ᨨ ᨨ鼀盐 ᨨAB ᨨ � � � 鼀� �ᆠ �  ᆠ O ᨨ  ᨨᨨ µ I 矄� �° + 矄� �°㡰 㦨 µ I B= p L ⏌ 㡰 pL I I ᨨ B µ ᨨB = K ( K = ᆠᨨ 矄  ) L L

㦨҈

ᔼ 盐ᆠ 鼀 㦨 㦨҈맔҈҈맔҈㦨҈m 㡰  � 盐ᆠ  鼀  w l l

l





᲼ l㡰  l㡰 桌 �Bl w =   l ҈ 㡰 ␔  ᆠ盐  ᨨ犨矄�  泐ᨨ  ᆠᨨ�矄  盐 � ├ 犨�  ᨨ ᆠᨨ��矄鼀 �鼀盐鼀犨  矄盐 ᆠᨨᆠ� 盐 �矄鼀 �鼀盐鼀ᔴ泐  盐 � ├��矄鼀 �鼀盐鼀� ᆠ矄 㡰 盐ᨨ 矄� �鼀 ᨨ  犨ᨨᆠ�ᆠ盐ᆠᨨ�矄 e=

ò wx㡰 Bdx = Bw

B A 꾀 鼀ᨨ�ᨨ  鼀   㦨  �矄 � 盐ᆠ  �    ᨨ  졠 犨 ᆠ  矄泐  ᨨ � �  ᆠ �矄 � 盐ᆠ l v 犨  犨ᨨ 矄ᨨ   ᨨ  꾀 犨�  꾀  ��  ᨨ �     ᨨ犨 B ᨨ � 盐 ᨨ  �矄 ᨨ � �  ᆠ  �矄  ᆠ�ᆠ � �  ᨨ  b㡰 ␔├ ᨨ犨鼀� �ᆠ �  盐ᨨᆠ盐  ᨨ犨� ��  犨�ᨨ  � � �  鼀� �ᆠ

B=



-҈ 

b㡰 ᔼ  �矄ᆠ矄 �矄  ᆠ�ᆠ � �  ᨨ 

㝐� �ᆠ 盐  � ├  犨�    KI  l 矄鼀 ᨨᨨ f = B A = L



꾀  f = ME

犨  M 㦨 㝐盐盐 � 盐ᆠ ᆠ KI  l l \M µ  \ MI = L L

df �矄 ᨨ dt  ᆠ� 盐ᆠ  鼀 ᨨ ᆠ盐  �   ᨨᨨ �矄 ᨨ ҈黨  ᆠᨨ� �矄 ᨨ├  � ᨨ 犨ᨨ�  �ᆠ ᆠᨨ�矄   ᆠᨨ

ᆠ � 

҈

㡰 和� ᆠ ᨨ ᆠ  �ᨨ 鼀� �ᆠ 盐 

L ⏌  ´ L ⏌  L ҈ ´ ҈  = = 㦨�맔҈ L⏌+ L⏌    R⏌´R⏌ R  = = = ҈� W \ Req㦨 R ⏌ + R ⏌    Leq � ´ ҈ -

�鼀ᆠᨨ 矄 t㦨 㦨맔҈矄 = R q ҈� E ҈� = 和 泐矄ᆠ盐   ᨨ盐�  泐 I㦨 㦨҈꾀 Req ҈�  T盐꾀ᆠᆠᨨ � �ᨨ 鼀� �Ἐ矄   盐犨  ᆠᨨ 盐ᆠ�ᨨ ᨨ 꾀 B  鼀ᨨ矄ᨨ 㜠 �矄� 盐 � ᨨ鼀 Fm  鼀� �ᆠ �  ᨨ� � � �    e v ᨨ矄�� z㜠 �ᆠ�ᨨ       ᆠᨨ 矄 犨�  � ᆠ  ᨨᆠ ᨨ犨 矄   ᆠ     꾀 犨� 졔 졔 A ᆠᨨ鼀 ᨨ矄�� 盐 ᨨ  �ᆠ� ᆠ泐 ᨨ  ᆠᨨ 矄 꾀 \ Leq㦨

҈

҈

҈�

㡰 쟼ᆠ�ᆠ �  犨�  A B � 盐ᆠ 矄ABCD 鼀ᨨ矄�

ᨨ  AD   BC  鼀�ᆠ 矄⼄盐 ᨨᨨ 鼀ᨨ矄 v � �矄ᨨ犨  犨� ᨨᆠ�泐 v� 盐 � ᨨ鼀鼀� �ᆠ � C  �ᆠ盐ᨨ  ᨨ D  矄⼄盐ᨨᨨAD   BC   �ᆠ盐 ᨨ  ᨨᆠ�泐矄 犨 矄  �ᆠ盐 ᨨ �  �  㡰 矄� �ᆠ盐 㜠�鼀⼄盐�ᨨ �  LR ᆠ�ᆠ盐� I㦨I ҈et/t㡰 V L 盐 I  =   t = R R - ù V ҈ é \  I = ҈ - e - Rt ⏌ L 㡰 = ҈ - e -t ⏌ ´҈ ú 㦨҈ �� 㡰 ê R  ë û \ t㦨黨䰘맔҈矄 »҈鼀矄 㡰 ᔼ 盐ᆠ  鼀 ᨨ 盐ᆠ  ᆠᨨ矄矄 MNQ 犨�  矄鼀 矄  � 盐ᆠ  鼀 ᨨ 盐ᆠ � 矄��  犨�MQ \ eMNQ =eMQ㦨 Bvl 㦨Bv맔R犨� 턼 �� ᨨ �

҈

é æ y ö f ù ur b 㡰 ෌�  B = B ê҈ + ç ÷ ú Kˆ V = V�ˆ êë è L ø úû ␔ ᨨ犨 ᆠᨨ 矄�   � � � 矄鼀  �  ᨨ  犨� 泐  �矄 ᆠ 泐 ᨨ鼀   ᨨ��� 

WWW.JEEBOOKS.IN

PS-249

Electromagnetic Induction 쟼鼀  � 盐ᆠ  ᆠᨨ矄矄    �

泐 Df =  ( 泐 ) 

é æ 泐 ö ù Df =  ê҈ + ç ÷ ú  泐 è ø ú ëê û







\ ᔼ 盐ᆠ 鼀 ᆠᨨ矄矄   ᆠᨨ鼀 ᨨᆠ�ᨨ

é b æ 泐ö ù é ҈ ù Df =   ò ê҈ + ç ÷ ú  泐  =     ê҈ + è ø β + ҈ úû  ë úû ë ê ᨨ β =  Df = ᔴ泐DfµL

 BV L  ᨨ矄�� 犨�ᨨ  �   ᆠ ᨨ �泐㦨  

 盐ᨨ  Df 犨�鼀�  矄鼀矄�矄 ᨨᆠ�ᨨ ᨨ 泐㜠 �矄�矄矄鼀L矄 ᨨ �ᨨ盐矄 ᨨb㦨Df㦨



b㡰

�㦨

e  㦨  �㡰᲼ᔴᨨ盐 ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ

R 犨 �  � � ᨨ 犨   ᆠᨨ鼀泐 � 矄�  ᆠᨨᆠ├犨�矄犨 � �� �桌

㦨�㦨

     ��㡰 ᲼ ᨨ犨    犨 �  � �    �� �   ᨨ犨   ᆠᨨ鼀泐� 矄� 桌

\ - 鼀

     =



\

 







ᨨ - 矄ᆠᨨ e ᨨ  泐 = 鼀 d� ⏌ dt 㡰 ҈  ᆠ㡰 쟼 �泐 U = L�  ᨨ盐 U ᨨ  泐 = \ L=  鼀㡰 � ҈   㡰 U = L� = � Rt  \ L㦨 ᨨ  泐㦨ᨨ 鼀㜠矄ᆠᨨ  � ᆠ㡰 \ L = -



d�҈ dt

= ᆠᨨ 矄  = m say㡰





   ���㡰 \ 㦨 鼀 ᲼ ᆠ矄矄 ᨨ鼀 㦨ᨨ 㦨鼀� 矄 ᆠᨨ 矄  ᨨ 㦨ᨨ 㦨��  ᆠ矄矄 ᨨ鼀 㦨ᨨ 㦨  ᆠ�  㡰�矄ᆠᨨᆠ桌 ᨨ鼀 �㡰  ���㡰

 é   ù  ê  ú �㦨 ë 鼀 û ᲼� ᆠ矄矄 ᨨ鼀 㦨ᨨ 㦨�ᆠᨨ鼀矄 ᨨ ᨨ鼀 㦨ᨨ 㦨�ᆠ  �矄 �ᆠ�ᨨ   ᆠ矄矄 ᨨ鼀 㦨ᨨ 㦨桌  ᆠ �  㡰 �矄 ᆠᨨᆠ   㡰

 盐 矄矄� �  ᨨ盐�    � �盐 犨� �  � ᆠ盐  ᨨ犨矄  ᨨ盐�    � � � �泐ᨨ � ᆠᨨ 盐ᆠ� � 犨� 꾀  ҈ m � x df㦨 ò px ´ pdx  dx ҈ᆠ鼀 x x m� f= = M�  ҈p � � m \ M = ҈p

æ d� ö ÷ dt ø

㡰 ᔼ 盐ᆠ emf e = - L ç è

꾀ᆠᆠᨨ � � ᨨ ⼄盐矄�ᨨ   ᨨ  ᆠ  � ᨨ  ᆠ盐 

ò  = - 鼀 ò Þ㦨  



m d� m  = ´ ҈ =  V p dt ҈p

 犨�  ᨨ   � 盐ᆠ  鼀 �    犨� ᆠ盐矄  �矄 ᨨᆠ  � �   鼀� �ᆠ 盐  盐 ᨨ ᨨ�ᨨ  ᨨ ᨨᨨ 꾀矄   ᆠ盐  �    � �盐 犨� �矄 ᆠ矄� �   � 盐ᆠ ᆠ盐 � 꾀�矄�  矄鼀 �ᆠ�ᨨ 矄 ᆠ盐  �    泐ᨨ 盐矄 ᨨ    � �盐 犨�  ᨨ ᨨᆠ 犨�盐矄�  bᆠ 㡰 犨 f 㡰 ᔼ 盐ᆠ ᆠ L =  ᨨ  泐 = � 鼀 ᔼ 盐ᆠ 鼀 �  犨�e㦨 M

æ dI ö -҈ çè dt = ҈ AS �� ÷ø

꾀  ᆠᆠᨨ � � ᨨ  泐Ἐ矄 犨

d� ᔼ 盐ᆠ 鼀  V҈ = - L҈ ҈ = -  ´ ҈ - ´ m dt

V L  ´ ҈  ҈ = = = V҈ L҈  ´ ҈   和� ᆠᨨ犨 ��  ᨨ 犨ᨨᆠᨨ�矄 ⼄盐 \ V҈�҈㦨V� � V ҈ Þ ҈ =  = � V҈  ҈ 쟼 �泐 W = L�  

\

 �㡰

҈  L� W    ҈ = = ´´  =  \ W҈ ҈ L �   ҈҈  æ yö  ෌�  b = B ç ÷ kˆ  矄� ᨨ 矄⼄盐ᨨᨨ㦨 a è aø 和盐ᨨ矄t㦨y㦨 t㦨ty㦨y ur ur 㡰 ᨨ鼀� �ᆠ 盐 f㦨 B  A

B y  a = B ya a df dy = - B a = - B av t 㡰 鼀  e = dt dt

\

f=

WWW.JEEBOOKS.IN

EBD_8341 PS-250

Physics 盐ᨨ �矄ᆠ盐  ᨨ �   � B犨� � ᆠ ᨨᆠ

 e  B av t 㡰 = [ 꾀 �ᆠᨨᆠ├犨�矄] R R 꾀矄ᨨᨨ�ᨨ矄 ᨨ犨 鼀� �ᆠ 盐 � ├ 犨� �� ᆠ矄矄  ᆠ � 盐ᆠ  ᆠ盐  ᨨ犨矄 �  矄盐ᆠ   �ᆠ�ᨨ  矄ᨨ 矄 ᨨ  盐ᆠ 鼀� �ᆠ 盐 � ├ 犨� �  ᨨ� 盐ᆠ ᆠ盐  ᨨ犨矄 �   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  㡰 쟼ᆠ 矄� 犨� � ᆠ ᨨᆠ矄矄 ᨨ犨 �  ��盐 꾀 ᆠ盐 ᆠ泐� �矄�鼀 � 鼀� �ᆠ �  � ᆠ矄 ᨨᆠ㡰 ur r ur B y ö æ F ҈ = � l ´ B 㡰 = � ç - a�ˆ ´  kˆ÷ = B y �ˆ ´ ˆ 㡰錐 è a ø ur B y + a 㡰 æ ö F  = � ç + a�ˆ ´  kˆ÷ = �B y + a 㡰 ˆ è ø a ur ur F  = - F      ᆠ 犨� X F҈ ᆠ ᆠ ᨨ盐 ᆠ  ᨨ  y  ᨨᆠ \�㦨

ur ur ur ur ur F = F҈ + F  + F  + F 

和ᨨ  ᨨᆠ �    矄泐矄鼀 T  F = 맔 a�T㦨F

mgR B  L vT =  � vT =   錐 mR B L ��㡰␔   ᨨᆠ�泐ᨨ  ᨨ �矄  ᨨ �矄鼀� ᨨᆠ�泐 v mgR v= T =   B  L 和盐矄�盐� �  �矄 盐 ᨨ ᨨᆠ�泐�  ⼄ ��㡰

F

g-

F Y

ᆠ㡰  ᨨᆠ ᨨ    ᨨᨨ

ur é B  a  v t 㡰 ù ˆ F = mg ˆ + F = ê mg -  ú 錐 R ëê ûú \

B  a v t 㡰 dv m = mg -  dt R

꾀ᆠᆠ�ᨨ  a = g -

dv

v

ᔼ �� ��犨� ò

B  a  v t 㡰 g-  mR

v 㡰t é B  a v t 㡰 ù ᨨ� ê g -  ú mR ûú ëê 

- B a  mR

=



t

ò dt

w

v

=

v t 㡰 =

)

X

t

B a  v t 㡰錐 mgR

(

q

O B

A dx

L

- Ba t mR ù mgR é ҈ e ê ú B a  ëê ûú ␔  鼀� ᨨᆠ�泐�矄 �  v t㡰 ᨨ矄 ᨨ  ᨨ  t mgR \ v t㡰㦨   B a �㡰 v ᨨᆠ�泐ᨨ  ᨨ   泐�鼀t \ᔼ 盐ᆠ 鼀 e㦨BvL 矄ᨨ� 盐ᆠ ᆠ盐 �  ᨨ ᔼ 盐ᆠ 鼀  BvL I= = R R

\

䰘

)

x

R

( Bat ) mR

(

㡰 �㡰 盐矄ᆠᨨ 矄� 矄鼀鼀 ᨨ  � dxᨨ 鼀 ᨨ OA  �矄 ᆠx ᨨ鼀 ᨨ��� 和鼀鼀ᨨ盐 ᨨ 鼀 � 盐ᆠ �  �矄矄鼀 �  盐ᨨ盐 � ᨨ鼀鼀� �ᆠ �  de㦨B dx㡰v … �㡰 犨 v�矄 ᨨᆠ�泐ᨨ 矄鼀 � dx v 㦨xw … ��㡰 Y

S

B a  v t 㡰 =e ҈ ᨨ mgR - B a t mR

B  L ҈ mgR g ҈ ´ = g- g=   mR  B L  

=t

é B a v t 㡰 ù   êg ú mR ú = - B a t ᨨ ᨨ� ê g mR ê ú ê ú ᨨ ë û

ᨨ ҈ - e

᲼Q ᨨ �矄鼀矄矄矄矄桌

T B  Lv = g … ��㡰 m mR 和ᨨᨨ 犨�ᆠ⼄盐�鼀� ᨨᆠ�泐犨  �矄ᆠᆠ�ᨨ

�矄 ᨨ�

F

 

… �㡰

Þ mg  T㦨maÞa㦨 g -

y졔a

B a v t 㡰 ˆ   = -�B aˆ = -  R �  盐犨  �ᆠ�ᨨ 

B  L v  ᨨᨨ矄� ᨨ �矄 鼀ᨨ�ᨨ 㡰 R

F = BIL =

\ ᨨ 鼀 ᆠᨨ矄矄  犨 ᨨ鼀�ᆠᨨ OA r

é x ù Br  w e = ò Bxw dx = Bw ê ú =   êë  úû  㡰 �㡰 ᨨ ��鼀 ᆠ   ᆠᨨ 矄盐ᆠ  矄 ᨨᨨ犨矄 和犨�ᆠ s�矄ᆠᨨ矄 �鼀t㦨 ᆠ��矄ᆠ矄ᨨ �ᨨ犨 ᨨ ᆠ盐 � L㜠Rᆠ�ᆠ盐�  ᨨᆠ盐  泐�鼀ἘtἘ I 㦨I ҈et⏌t㡰  I S e B wr  I = = O R R R A L  t = R æ Rö -ç ÷ t L Bwr  \ I = ᲼҈ - e è L ø 桌 R r

WWW.JEEBOOKS.IN

PS-251

Electromagnetic Induction ��㡰 ᔼ  矄 泐 矄

=-

æ Rö B wr  ᲼Q t 矄�盐  - çè L ÷ø t ® 桌 I= e R 和� ᆠ ᨨ �矄ᨨ� �� �ᆠ 犨ᨨ├  矄ᨨ  ᨨ  ᨨ ├ �  ᆠᨨ 矄   �盐 矄  꾀 ᆠᨨ 矄   �盐 矄   ᨨ⼄盐 㦨  t㦨t ᨨ犨 ᨨ矄矄 盐ᨨᆠ盐  I

d é æ҈  öù B ç r q÷ ú = - ҈ Br  d q = - ҈ Br  w [Q q = wt ] øû dt êë è    dt

\ ᔼ㦨

E ҈ Br  w ҈ Br  w =Þ I = R  R  R



æ Br  w ö P= I R= ç ÷ R è R ø ᔼ ᨨ⼄盐⼄盐�  ᨨ  �矄 ᨨ犨 �矄 t1  

r⏌



q

r  ᆠᨨ矄q

t 㦨

mg

B  r w R

ᨨ⼄盐 ᨨ  犨��  鼀�㡰 ᨨ盐 ᆠ  r t  = mg ´ ᆠᨨ矄 q 

 ᨨ ᨨ⼄盐 t㦨t҈졔t ᔴᨨᆠ├犨�矄㡰

P = t҈w  Þ  t҈ =

B  r  w mgr + ᆠᨨ矄 wt R 

 ⼄盐� ᨨ⼄盐 犨�  ᨨ 矄鼀 鼀� �盐   �

 �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ    ᨨ⼄盐 犨�     ᨨ    �盐矄 ᨨ  ᨨ 犨�鼀� �  ᆠᨨ 矄  黨  �ᆠ�ᨨ  ᨨ  � 盐ᆠ  ᆠ盐  R҈ ᆠ   ᨨ盐  犨�     ᨨ A C �҈  矄犨 ᨨ � �  ᆠ ᆠᨨ矄矄 B �҈+�)l  ᆠᨨ鼀� �ᨨ 矄 鼀� 矄 e   矄鼀 꾀矄ᨨP҈㦨e�҈㦨䰘␔ E L �҈+� F  P㦨e�㦨҈␔ mg � ҈䰘 ҈䰘 � � … ��㡰 Þ �҈ = \ ҈ = D B ҈ � ҈ R

 ᨨ� ᨨ 鼀�ᆠL鼀ᨨ矄犨� 鼀� ᨨᆠ�泐 �   ᨨᆠᨨ  �矄 ᨨ \ B �҈졔�㡰㦨mg mg  ´ 黨 黨 Þ �҈졔�㦨 鼀  ���㡰 = = Bl  ´ ҈ ҈� ᨨ鼀⼄ ��㡰  ���㡰 ҈䰘 黨 � + � = ҈ ҈� ҈黨 䰘 Þ �㦨꾀 Þ  �҈ = 꾀  Þ  e = = V ҈� ҈黨 ⏌҈� ᔼ 盐ᆠ  鼀 ᆠᨨ矄矄 L 盐 ᨨ  鼀ᨨ鼀  ᨨ  L �  鼀� �ᆠ � e  = = ҈鼀⏌矄 e㦨BvTL Þ vT㦨 BL  ´ ҈ 꾀矄ᨨ ᨨ鼀⼄ �㡰  e e  = 䰘W   R = = R҈ = = =  W �҈ ҈黨 ⏌҈� �   �㡰 ᔼ 盐ᆠ  鼀

��㡰 ␔   ᨨᨨ�矄 � ��  鼀� �ᆠ � ��

��ᨨ ᔼᔼ鼀� �ᆠ� 矄ᨨ  ᨨᆠ矄矄� � ᨨ盐�  ᨨᨨ �矄� ᆠ矄� ��   ᨨ犨 犨  �ᆠ�ᨨ   ᨨ矄   Ἐ矄犨ᆠ盐 犨� ᨨ犨�  ᨨᨨ� 矄盐ᆠ  �ᆠ�ᨨ

犨 �ᆠ 犨�ᨨᨨ矄 ᆠ  � ᆠ ᆠ盐 犨� ᨨ犨 �     �㜠ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  ���㡰 ෌  犨  � 盐ᆠ  鼀   �ᨨ  ᨨ ᨨ�ᨨ  ᨨ �矄  ᨨ�ᨨ  t㦨 T⏌㡰 犨     ᨨᨨ  矄   �    ᆠ盐  �矄 �   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  㝐� �盐 ᨨ ᆠ盐 鼀� 矄ᆠᨨ 矄  I = Bwr  ⏌  R  ᨨ     ᨨ�ᨨ  犨     ᨨᨨ ᆠᨨ鼀矄 ᨨ盐 ᨨ    �  ᆠ盐  ᨨ  矄鼀鼀� �盐  �矄 矄 盐 ᆠᨨᆠ├犨�矄 꾀 �ᆠᨨᆠ├犨�矄 ᆠ盐  �矄 矄盐ᨨ矄  ᨨ  ᨨ矄��  I㜠t �  ᨨ 犨ᨨ�ᨨ 矄 ᨨ ᨨ�ᨨ  矄 矄 ᨨ犨  ᨨ犨 I Bw r  R

t=

E=-

df d = - B ´ A㡰 dt dt

T⏌ T T⏌ T

҈

t

 犨ᨨ├  矄 �├   ᆠ  犨 矄ᨨ  � � 和ᨨ ᨨ ᆠ盐  ᨨ犨矄  ᨨ盐�  AC

\쟼⼄盐� 矄�矄 ᆠᨨ  ᆠ�ᆠ盐�R㦨졔҈㦨W

鼀 � 盐ᆠ e㦨BVl IR e㦨IR㦨BVlÞV㦨 Bl ҈ ´ ҈  ´  ᨨ V = = 鼀⏌矄  ´ ҈

  ᆠᨨ 矄 �    ᨨ�ᨨ  MN ᨨ   ᨨ    ᨨᆠ�泐 v �    ��  �ᆠ�ᨨ 꾀泐� � 鼀� �矄    盐犨 �    ᨨᆠᨨ ᆠᨨ 犨�ᨨ犨 矄 N ᆠM犨�졔 N犨� ��ᔴ盐  犨� ᨨ犨� ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ 

WWW.JEEBOOKS.IN

EBD_8341 PS-252



Physics

B㦨맔҈wb⏌m l㦨҈鼀 I҈(t)

180 km/h=50m/s

B (t) I t㡰B t㡰

1m ᔼ2 (t)

�鼀

鼀  ᨨ  盐ᨨ 鼀ᨨ�ᨨ  鼀  㦨 l 㦨�맔맔҈맔҈㦨҈㦨҈鼀

 � �ᨨ 鼀��ᨨ鼀�矄҈mv

�

Topic-3 : Miscellaneous Problems ҈





Þ E pr 㡰 = pa 

㡰 꾀矄 ᆠ泐�  �矄 ├  ᨨ   盐 � ᨨ鼀 鼀� �ᆠ �  矄ᨨ ᨨ ᆠ  � �  鼀� �ᆠ 盐     ᆠ � 盐ᆠ ᆠ盐 犨� ᨨ 



҈ a  dB ÞEµ r r dt  ᆠ鼀� �盐 ᨨ  � 盐ᆠ ᆠ�ᆠ �  �矄 ᆠ

l 桌 A



ᨨ P㦨

pr    æ dB ö N r  N A ç ÷  Þ  P µ è dt ø l rl  N 㡰 r ⏌ 㡰 l

P ҈ = \ᨨ犨鼀� 矄 矄鼀 rἘ ҈ 㡰 ␔  矄犨�ᆠ S�矄ᆠᨨ矄 鼀� �ᆠ � �矄矄㜠盐�

  矄ᆠᨨ盐  P  �  � 矄   � � Q � ᆠ矄矄 �   �ᆠ�ᨨ  ᨨ鼀�� ᨨ 꾀ᆠᆠᨨ � �ᨨ Ἐ矄犨 IQ҈  犨�  ᨨ犨 矄ᨨ 矄 ᨨ ᨨᨨ矄   ᆠ盐矄 ᨨ ᆠ �  ᨨ犨 �   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  矄 矄  泐E 졠ᨨ矄� �矄  ᆠ矄犨  S �矄 ᨨ   IQ 犨�ᆠᨨᆠ├犨�矄 b㡰 꾀ᆠᨨ 盐ᆠ� �� ��矄ᆠ ᆠᨨ �泐犨� � ᆠᨨ�  ᆠᨨ� 矄� 盐ᆠ ᆠ矄犨矄矄�矄 ᆠ 鼀� �ᆠ �     ᆠ  ᨨ    ᆠᨨ� B t㡰㦨ҘnI҈ 꾀矄 ᆠ盐 � ᆠ矄矄B 犨�矄ᨨ� ᆠ矄犨� �鼀� � ᆠ 矄  鼀 �鼀盐鼀 盐 犨     ᆠ盐  ᆠᨨ鼀矄 矄 泐㡰 ᔼ 盐ᆠ 鼀 �  � � df d ur ur d e= = - B A㡰 = - A µ nI҈㡰 dt dt dt \ᔼ 盐ᆠ ᆠ盐 �  � �  e  µ nA dI҈ I  t 㡰 = = R R dt dI҈ ᲼  ᆠ矄矄犨� �鼀   ᆠI矄ᨨ ᆠ矄矄犨� dt �鼀桌 ␔ I҈㦨Imax ҈et⏌t㡰

   � 矄  矄 ᨨᨨ犨矄



䰘

\





҈  r ᆠ㡰 ᨨᨨ㜠꾀ᆠ�矄  ᆠ盐 꾀      ᆠ盐  �    ᨨᨨ A � ᆠ矄矄 犨�  �鼀   鼀� �ᆠ � 矄 ᨨ  ᨨᆠ �

ᨨᨨB 矄ᨨ� ᆠ矄矄矄ᨨᨨA �矄ᆠ  ᨨᨨB �矄 � 盐ᆠ矄 鼀 � B � 矄盐ᆠ  �ᆠ�ᨨ  ᆠ盐  ᨨ犨矄 ᨨᨨ矄�� B 矄ᆠᨨ鼀 ᨨA  ᆠ ᨨᨨB �矄 泐ᨨᨨ A  b ᆠ㡰  꾀  㦨  � 盐ᆠᨨ矄 L҈   L 犨� ᨨ  � � � 矄�矄 ᆠ  ᆠ ᆠ盐   ᨨ盐�  ᆠ�ᆠ盐� �矄 ᨨ 꾀 ᨨ ��鼀 ᆠ盐  ᨨ盐�  矄�矄ᨨ�矄ᆠᨨ 矄  ᔼ犨� �� � ᨨ犨ᨨ矄҈ 犨 �ᆠ �  \ᔼ҈҈㦨ᔼ᲼ᔼ㦨ᔼ҈졔ᔼ桌 r ᨨ鼀 ᆠ  ᨨ ᆠ�ᆠ盐 ��ᨨ  ᆠ矄矄 矄

␔   盐鼀 ᨨ 盐 矄 ⼄盐 盐      犨�  �盐矄   ᨨ犨 r Ἐµ

dB fᨨr r ³ a dt

Þ E=



b㡰 ᨨ犨 P = E = pr çæ d f ö÷ = pr é d NBA㡰 ù úû R rl è dt ø rl êë dt ᲼E㦨� 盐ᆠ 鼀   R = r

�鼀

 ᆠ 矄  盐 ᆠ�ᨨ  ᨨ �鼀 >㡰   ᨨ 盐ᆠ I t㡰  t㡰 ᆠ矄矄 犨�  �鼀 ur uur d f d ur ur d dB b㡰 Ñ ò Ed l = dt = dt B A㡰 = dt BA ᆠᨨ矄 °㡰 = A dt

I҈ =

V é L҈ ù R êë L҈ + L úû 꾀矄ᨨ �ᨨᨨ ᆠ盐 矄 ᨨ盐� ҈ �矄 �    �鼀矄꾀㦨 I »  b 㡰  鼀� �ᆠ 盐  ᨨ盐�  ᨨᨨ矄�鼀t f㦨BA ᆠᨨ矄wtBAᆠᨨ矄wt 㦨B AA㡰ᆠᨨ矄wt㦨BAᆠᨨ矄wt df = BwA 矄� wt \ dt 



V é L ù R êë L҈ + L úû I =

df �矄鼀 �鼀盐鼀犨  f㦨wt㦨p⏌ dt

鼀 � 盐ᆠ �  矄鼀ᨨᨨ 和ᨨ

d ( BA ᆠᨨ矄 wt ) = BwA 矄� wt dt \꾀鼀�盐 ᨨ 鼀 �鼀盐鼀 鼀 � 盐ᆠ � ᨨ  ᨨᨨ矄 㦨꾀鼀�盐 ᨨ 鼀 �盐鼀鼀 � 盐ᆠ �  矄鼀ᨨᨨᨨ  dQ =I = ᆠ 㡰 ᨨ鼀 �鼀盐鼀ᆠ �ᨨ  ᆠᆠ�ᨨ dt I㦨Iᆠᨨ矄wt㦨ᆠᨨ矄�t

e矄鼀 = 

黨

WWW.JEEBOOKS.IN

PS-253

Electromagnetic Induction I

ᨨ鼀⼄ �㡰  ��㡰

҈

D㝐㦨 -g 鼀 ç

p w

 æ 턼 ö  - g턼 = ÷ è 鼀 ø 

䰘p w

p w

t

2p w

҈ ҈ D

B A

�

C㦨m F

R㦨҈W

҈

䰘p p

�  =  ᆠ �犨�鼀 �鼀盐鼀 w w p ⏌ w

턼¢ =

ò



p ⏌ w

é 矄� �t ù ᆠᨨ矄 �t  㦨 ê ú ë � û 

҈ p ö ҈ æ 矄� ç � ´ ᔴ 㦨 ÷= � è  ´ � ø � ҈ c =  ´ ҈  C �Qmax㦨 �

\

ᨨ鼀   �  � �矄 ᆠ   盐矄  ᨨ t = ᆠ盐  �矄 �   �ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ  ᔼ鼀鼀 �泐 A�矄 ᆠᨨ

ᆠ  ᨨD 꾀 t = 䰘p w

æ

䰘p

dfù é êQ e =  dt ú ë û

ö

pµ na  �w ᆠᨨ矄 wt e =   pRp 㦨 矄�矄 ᆠ Ld

҈ ҈ ´ = -҈ - ᔴ  = �  ᨨ犨泐� �⧤

҈

҈҈

ò \

҈

- � ´ ҈ =  Þ�㦨҈꾀

 ´ ҈ -

鼀 �鼀盐鼀ᆠ �ᨨ CQ㦨CV 㦨맔҈맔�㦨҈ᔴ

 ᨨ ᨨᆠ � ᨨ犨  ᨨ鼀 泐㦨맔҈ᔴ ҈ bᆠ㡰  R⏌L   ҈⏌ LC    �鼀 矄�ᨨ 矄 ᨨ RC ⼄盐 ᆠ泐�᲼M L  T҈桌 b㡰

® ®

쟼   㦨

L

pl A r ´ pR pRr \ 矄�矄 ᆠ R = ᨨ 矄�矄 ᆠ㦨 L´d Ld \ᔼ 盐ᆠ ᆠ盐 � 矄 ᔼ



҈ -

d

矄�矄 ᆠᨨ 矄  R =

ò ᆠᨨ矄 �t  = � 矄� çè � ´  ´ � ÷ø

� +

df = pµ na  � wcᨨ wt dt

ᨨ e =  pµ n a  � w ᆠᨨ矄 wt

䰘p    w

䰘p    ᆠ � ᨨ    盐 ᨨ ᆠᆠ�ᨨ w

҈

  㡰 矄��  矄 ᨨ犨矄   ᆠ  � �矄 ᨨᨨ矄� ᨨ   �ᆠ�ᨨ ᨨ 鼀� �ᆠ �  㡰 �矄   ᆠᨨᆠ ᨨ�ᨨ  㡰  ᨨ� ᨨ  ᆠᨨ鼀ᨨ   F I ᨨ    鼀� �ᆠ �    I � ᆠ矄 犨�    � 盐ᆠ ᆠ盐  ᨨ 盐ᆠ  �    ᆠᨨ 盐ᆠ� � � � 犨 �ᆠ BH ᨨ 盐ᆠ矄   � ᨨᆠ �

  盐犨  �ᆠ�ᨨ  �矄 �矄 ᔴᨨ 盐ᆠ� �� �   ᆠᆠᨨ  ᆠ 犨�  鼀� �Ἐ矄     盐 꾀 ᆠ泐� �ᆠ 矄  ᨨ  �    �ᆠ├ 矄矄     �盐矄 矄盐ᨨ盐 矄  ᆠᨨ � 矄ᨨ ᨨ�  ᨨ  �盐矄 a  ᆠᨨ� ᨨ   矄ᨨ ᨨ�  ᆠ�矄  �ᆠ盐  �㦨 �矄�  wt 졠盐矄�   矄ᨨ ᨨ�   鼀� �ᆠ �  �矄 ᨨ 㝐� �ᆠ � � 矄�  矄ᨨ ᨨ� 㦨Ҙn�矄� wt \㝐� �ᆠ 盐 � ├ 犨� 矄ᨨ ᨨ� f㦨BA R ᨨf㦨 Ҙn�矄� wt㡰 pa㡰 a

 - f = - p  㡰 = -p    

\ᔼ 盐ᆠ ᆠ盐 㦨 ҈�

µ na  Ld � w ᆠᨨ矄 wt  rR

㡰  盐矄 ᆠᨨ 矄�   矄鼀 矄� ᨨ   �ᆠ├ 矄矄 dx   �矄 ᆠx ᨨ鼀  犨�꾀矄 矄 ᨨ犨 �   ��盐  鼀� �ᆠ �  �矄矄� 盐ᨨᨨ 犨�矄 B㦨BA졔BB  �ᆠ盐 ᨨ     ᨨ   �ᆠ  盐犨 矄㡰 B㦨

m I m m I é ҈ I ҈ ù + + 㦨 ê p x p a - x 㡰 p ë x a - x úû

 = - p   dx

쟼맔p 㦨p 

-  \ 쟼㦨  b㡰 ෌� 㝐㦨g  \ 㝐㦨g 鼀w  \ 㝐㦨g 鼀 Dw㡰  턼맔 盐Dw㦨 鼀

I

x

 ҈㡰  㡰

和鼀鼀ᨨ盐 ᨨ 鼀� �ᆠ 盐 矄矄� � ᨨ盐�  矄�ᨨ  �ᆠ├ 矄矄 dx

WWW.JEEBOOKS.IN

EBD_8341 PS-254

Physics

ᨨ⼄盐 ᨨ盐 PQ 泐 �矄 ᨨᆠ r r ur $ $ $ t RS = r ´ F 㦨 � a㡰 ´ k - � 㡰 IbB 㦨 I abB  $ 㡰

m  Ia ´ a dx  p x a - x 㡰

ᨨ 盐  ᨨ盐�    矄⼄盐 ᨨᨨ df㦨B맔adx㦨

f㦨 ò

a a

 ��㡰 

ᨨ⼄盐ᨨ盐PQ 盐 ᨨ犨�� ᨨ  犨�PQRS

m  I ´ a  m Ia dx =    x a - x㡰 p p

m  a  㡰  I矄� wt㡰 p m aI w df =    㡰 ᆠᨨ矄 wt

鼀 ᨨ 盐ᆠ e㦨 dt p ᔴ �矄ᨨ  �    ᆠᆠ�ᨨ m  aI  w q㦨C맔e㦨C맔   㡰ᆠᨨ矄wt  �㡰 p \ ᔴ盐  �   ᨨᨨ ᨨf 㦨

dq C ´ m aI  w  =  㡰矄� wt �㦨 dt p

æ aö  ���㡰  㡰㝐� �ᆠ ᨨᆠᨨ  矄 ᨨ鼀⼄ �㡰FRS㦨ᔼ ékˆ  �ˆ ù ë û ᆠ㡰 ᨨ 犨�ᨨᨨᨨ ᨨ� ᨨ  t㦨mg ç ÷ è ø

a mg Þ I㦨  �㡰  bB 꾀矄 ᆠ盐矄 ᨨ⼄盐 盐 ᨨ鼀�   ᆠ盐  �  ᨨᨨ矄� �ᆠ�ᨨ 矄  ᨨᆠ盐 �矄 ᨨ鼀 Pᨨ Q ҈䰘 �㡰 꾀矄矄 ᨨ犨 �  ��盐� ᨨᆠF�矄� ᨨ ᨨ MN矄盐ᆠ  矄 ᨨ 鼀ᨨ矄�  盐 � ᨨ鼀鼀� �ᆠ � 꾀 ᆠᨨ 矄 ᆠ盐  ᨨ犨矄  ᨨ盐�  R ᔴᨨ 矄�  ᨨᨨ MPQN. MN �矄 ᆠx ᨨ鼀PQ.  � ᨨ �矄� ᨨᨨ㦨x IabB㦨mg

m  aI  w  C  㡰 p 㡰 ᨨ鼀⼄ �㡰 � 犨 ᆠ � �鼀 q  t㡰 �矄 矄 矄 ᨨ犨  ᨨ犨 \ �鼀 㦨

q

q

p/w p/2w

2p/w

t

3p/2w

 q

ᔴ �ᨨ 盐ᨨ ᆠᆠ�ᨨ q㦨 qᆠᨨ矄 wt

C ´ m  aI w  㡰 p ҈ 㡰 盐矄ᆠᨨ 矄�  ᆠ盐 �  ᆠᨨᆠ├犨�矄 �ᆠ�ᨨ

� ᨨᨨPQRS �PᨨQ�  犨�PQ ᨨᆠᨨ 犨�QR ur r ur F = I l ´ B㡰 㦨 I ᲼ a�$㡰 ´ �$ + k$ 㡰 B 桌 q㦨



QR

㦨 I B ᲼a�$ ´ �$ + a�$ ´ k$ 桌 㦨 I B᲼졔a  $ 㡰桌㦨 -aB I $ Z

\ 矄�矄 ᆠᨨ �矄� ᨨᨨ㦨xl \ ᨨ矄�矄 ᆠᨨ ᨨᨨ R 㦨R졔lx V ᨨᆠ�泐ᨨ ᨨ  �矄� 矄    盐ᨨ  鼀ᨨ�ᨨ ᨨ  ᨨ 鼀 � 盐ᆠ e㦨Bvd \ ᔼ 盐ᆠ  ᆠ盐  I㡰 =

e Bvd = Rnet R +  lx

R + lx 㡰 I  �㡰 Bd 꾀  盐 ᨨ � 盐ᆠ  ᆠ盐  I   犨� 犨�  � ᆠ  ᨨᆠ FM 㦨 BId ᨨᨨ矄� ᨨ �矄 鼀ᨨ�ᨨ    ⼄盐�ᨨ  ᨨ 鼀ᨨ�ᨨ ᨨ  犨� F  FM = ma Þ F = FM 졔 ma 盐矄 FM = BId  ᨨ鼀⼄盐�ᨨ  �㡰 和ᨨ ᨨ ᆠᨨ 矄  I

v=

dv  lI dx  lIv  lI  = = = R + l x 㡰 dt Bd dt Bd Bd 㡰   lmI  \ F = BId + R +  lx 㡰 Bd 㡰  ��㡰 꾀矄   犨ᨨ├ ᨨ  泐 ᨨᆠ F  矄ᆠᨨ  é ù é R +  lx ù lmI  dW P Fv BId R + l x 㡰 ú ê Iú = = = + ê  dt  û Bd 㡰 ëê ûú ë Bd

a=

B

>

k 졔 �

>

>

P

k

Q

Y

X S

R

ᨨᆠᨨ 犨�PS ur r ur F PS = I l ´ B 㡰 = I ᲼a -$� 㡰 ´ $� + k$ 㡰 B 桌 㦨 aB I $ � ᨨᆠᨨ  QR �矄 ⼄盐   ᨨᨨ矄� ᨨ   ᨨ  PS   ᆠ ᆠ  ᨨ  ᨨᆠ ᨨ  RS ur r ur F RS = I l ´ B 㡰 = I ᲼b - $ 㡰 ´ $� + k$ 㡰 B 桌 㦨 I bB ᲼k$ - �$桌



 �㡰

é

� P = ê I  R + lx 㡰 +

êë

lmI   

B d

ù R + lx 㡰 ú úû

   ᨨ 盐ᆠ   矄ᆠᨨ 

H = I  R + lx 㡰 \

f =

H é  lmI R + lx㡰 ù = ҈+ ú P êë B d  û



WWW.JEEBOOKS.IN

PS-255

Alternating Current

Alternating Current

21

Topic-1 : Alternating Current, Voltage and Power ҈

㡰 꾀矄V t㡰㦨矄� ҈p

Topic-2 : AC Circuit, LCR Circuit, Quality and Power Factor ҈

 矄ᨨI t㡰㦨 矄� ҈p � �I㦨Im㦨矄�  ҈p㡰 ᨨI㦨Im t҈ =

Þ



Im 

Im ҈ p = Im 矄� ҈ pt 㡰 Þ = ҈ pt  Þ t  = s   

҈ ҈  ҈ = = s =  鼀矄     㡰 ᨨ 犨ᨨᆠᨨ ᆠ �ᆠ ᆠ�ᆠ盐 ᆠᨨ� \ t⼄ =



㝐盐盐 ᔼ 盐ᆠ ᆠ㝐 =

m  p҈    

҈㦨㦨҈

m  p   �㡰   �� ᔼ㦨ᔼᆠᨨ矄w  ��㡰 ᨨ犨 ᆠᆠᨨ � � ᨨ  泐Ἐ矄 矄ᆠᨨ  犨 � 盐ᆠ  鼀

 ᆠ㝐 =

ᔼ  ᨨ鼀⼄ ��㡰  = -㝐

-m  p  = ᔼ ᆠᨨ矄 w 㡰  

=



҈ L ҈  ´ ҈ - = R C ҈  ´ ҈- ҈   ´ ҈ = =  = ҈ ҈ 㡰 ᨨ �  �泐 矄ᨨ  �    � 盐ᆠᨨ ҈ U = LI   盐� � �ᨨ犨  ᨨ ᆠ盐  �㦨I鼀  ҈eRt/L㡰 I U ᨨUᨨ 鼀 錐� 矄ᨨ 鼀 n n I 鼀 \ = I 鼀 ҈ - e - Rt ⏌ L 㡰 n ҈ n -҈ Þ e - Rt ⏌ L = ҈ = n n æ ö L æ n ö Rt n -҈ Þ - =  çç Þ t =  çç ÷÷ ÷ L R è n - ҈ ÷ø è n ø 㡰 R㦨҈XL = Lw㦨҈맔䰘�맔p 㦨�W, ҈ ҈ XC = = -� = ҈W C w ҈ ´  p ´ 䰘� Q=

p ҈ ҈ 矄ᆠ ´ =  ҈ p 

  ᨨ I =

㡰 턼盐�泐 ᆠᨨ



ᔼ鼀  ᆠZ㦨 R  + X L - X C 㡰  

㦨 ҈ + � - ҈㡰  㦨䰘䰘 ; �





æV ö  H = �鼀矄 Rt = ç 鼀矄 ÷ RT è Z  ø

m  p  ᔼ 矄� w  w 㡰 

pm ᔼ    =    w 矄� w    b㡰 ᔼ 盐� 盐ᆠ�ᆠ�ᆠ盐�ᆠ盐 犨泐矄�矄  � p  鼀  泐   ᔼ   (  ) =  矄� w pö æ    ᔼ = ᔼ 矄� ç w - ÷ è ø ᨨ犨��  㡰㦨҈矄�  �㡰 쟼 ҈   ᔼ =  =  [Q  =  ] w � ´  pö æ ᔼ = ҈矄� ç � - ÷ ø è ᔼ = -҈ᆠᨨ矄 ( � )

҈W

҈

҈m

㦨 ms㡰Dt

  ⏌䰘� ´ ´ ҈t = 㡰 ´ ҈ � � QV鼀矄 =    D㦨҈ ᔴ \ �鼀t㦨҈矄 㡰 ෌�  ᆠ ᆠᨨ � 盐ᆠ ᆠᆠᨨ�Z 㦨 ҈W ⼄盐 ᆠ泐ᨨ 꾀ᔴ矄�� v㦨҈  矄 �f㦨� X  f = L =  �° = ҈ Þ X L = R R

Þ



ᆠ ᆠ Z = ҈ =

Þ ҈ =

X L + R 

R + R

Þ  R = ҈ Þ R = �  \ X L = � 

WWW.JEEBOOKS.IN

EBD_8341 PS-256

Physics

Q X L = wL㡰

Þ Lw = � 

ÞL=

�  p ´ ҈

=

Q w = pv㡰

�  鼀㦨҈҈맔҈ p e -t ⏌c 㡰 b㡰 ␔ �㦨� ҈et⏌c㡰㦨 ҈ - e R  =

�

҈҈

t

ᔴ �q㦨 ò �dt

e

t



EL 㡰dt 㦨 E t 㦨 E ´ L ⏌ R 㡰 㦨 Re R e 䰘 R   æ d� ö d� �  = ᆠ㡰 � R = çè t ÷ø � Þ dt dt t 㦨 R ò ҈ - e



䰘

-t ⏌t

e e  ´ ҈� = = = 꾀 � æ ´ ö  çè ÷ + ø ᨨ 盐矄㡰 ᔴᆠ�� ᆠ ᆠ



Xc 㦨

҈  ´ ҈ 㦨  㦨 wᔴ  ҈ ´  ´ ҈



ᔴ

XL㦨wL㦨 ҈ ´ R҈㦨҈

黨









 ᆠ盐  犨� �ᨨ犨 ᨨ   �鼀  㦨  ᨨ  㦨        ᆠ泐ᨨ ᆠ盐  ├矄 ᆠ 㡰 ෌� ᔼ 盐ᆠ ᆠL㦨鼀 ᔴᆠ� ᆠC㦨҈mF ᔼ鼀  ᆠZ㦨XCXL

҈  wL wC

ÎL

=  kx  bv dt  md  x dx Þ + b + kx =   �㡰  dt dt q Ld�  �R  = ᔼ ᔴ ᆠ�ᆠ盐� C dt d dq q L  + R + =   ��㡰  dt C dt



 q㦨  Þ q㦨  ҈ 㡰 q㦨 和ᨨ  矄 �  ᆠ ᆠᨨ鼀矄 � ᨨ盐黨 졔 㦨҈� ᔼ  �矄⧤W    矄 �  ᆠᆠᨨ鼀矄ᨨ盐ᨨ졔㦨黨  b㡰 ᔼ

Þ Z=

\q =

md  x

q2



҈

tc Îé t + tC e  t ⏌ tc ù ë û  R t Îé ù Þ q = êtC + C  tC ú  Þ q = Î L Rë e R  û

 

)

R e ҈ 㡰 ᔼ  鼀  鼀ᨨ �ᆠ ᨨ矄ᆠ��ᨨ 

q1

 q㦨 ҈

(

E ҈  e  t ⏌ tc dt R

Þq=



 㦨 ҈  ҈

ò �dt

Þ ò dq = ò



҈

 q҈㦨 㦨   q҈�矄ᆠᨨ矄ᨨ黨 ᨨ㜠 ᆠ�ᆠ盐�

Tc 



e

V 矄� wt + p ⏌ 㡰 ᔴ盐  � = Z ҈ Þ �= ᆠᨨ矄 wt 㦨�ᆠᨨ矄 ҈㡰 ҈黨 㡰 ᨨ 矄�矄 ᆠᨨ

ᆠ�ᨨ  ᨨ  矄�矄ᨨ  � 盐ᆠᨨ �鼀 ��ᨨ ᨨ ᆠ盐 �矄 I = I ҈  e  t ⏌Tc 㡰 L  TC = R q=

L  é ù = ú Þ㦨t l 㦨l  ê 矄t = = R ҈ ë û 㡰 ᨨ � �鼀  矄犨�ᆠ  �矄 ᆠᨨ矄    � 盐ᆠᨨ 犨� � 矄ᨨ ⼄盐�  ��鼀犨�矄ᨨ犨 ᔼ=

҈  ҈ ´  ´ ҈  㦨҈黨W ҈ ´ ҈ ´ ҈ 

҈ æ ö  X L = wL÷ çèQ X c = ø wC

҈

ᔴᨨ鼀� �⼄盐�ᨨ 矄 �㡰 ��㡰 ҈ L « m C «  R « b k 㡰 ᆠ盐  ᔼ㡰�  矄�矄ᆠ�ᆠ盐��矄�� 泐 tR æ  ö V I = ç҈  e L ÷ ÷ Rç è ø 꾀t㦨¥ ¥ ö æ  ç L I¥ = I  e ⏌R ÷ =   �㡰 ÷ � ç è ø 꾀 t㦨矄

 ´ � ö æ =  ҈  e  㡰 çè҈  e  ÷ø ҈ ´ ҈ �� � � �㡰泐 ��㡰犨�

 ��㡰

I¥ ҈  = I  ҈ e  ҈ b㡰 꾀矄犨├ ᨨ犨�ᨨ犨�㦨鼀矄ᔼ鼀矄ᆠᨨ矄q Þ

æ  öæ ᔼ ö æ ҈ ö æ  ö = ç  ÷ ç  ÷ ᆠᨨ矄 q = ç ÷ç ÷ ᆠᨨ矄 �° Q q 㦨� 㡰 è  øè  ø è  øè  ø

WWW.JEEBOOKS.IN

PS-257

Alternating Current � =

҈



犨

 ␔矄矄ᆠ盐 ᔼ㦨 ᔼ鼀矄 矄� q ᔼ  矄� �° = ҈꾀 =  矄� q =   w w  =  ҈� 㡰 턼盐�泐 ᆠᨨ 턼 = Dw ҈ b㡰 ෌�  㦨ᨨw㦨 㦨�W㦨�鼀ᔴ㦨҈Ҙ 㦨w㦨맔�맔҈㦨W ҈ ҈ ᔴ = = = ҈ W wᔴ  ´ ҈ ´ ҈ -

ᨨ�鼀  ᆠᨨ  ᆠ�ᆠ盐�

҈䰘

 =  +   - ᔴ 㡰  = � + 黨㡰  = 䰘 W  矄 �  ᆠ 犨    ᨨ�   ᆠ盐   - ᔴ  f =  黨  f = » ҈ Þ f = �° � b㡰  �㦨

e 

R +

e 

 

R +w L



҈㦨

҈

=

X L

҈�´҈

q d� - �R - L =  c dt







�  

�

 졔  ⼄ ᆠ

dq q dq Ld  q = � =- Þ + R+ dt c dt dt 

R dq q + = L dt Lc dt ᨨ鼀 鼀  鼀ᨨ �ᆠ ᨨ矄ᆠ�ᨨ  鼀�盐 �矄 ��

dt 泐꾀 = Aᨨ e m ᨨ盐 �  � ⼄盐�ᨨ



d x dt



+

+

b dx k + x= m dt m -

Rt



-

Rt

 = Qᨨe L Q鼀 = Q ᨨe  L Þ Q 鼀  ᆠ 鼀� �犨�  矄 ᨨ 矄矄矄 � 盐ᆠ ᆠ

w L 





 

VR = -҈ VC



ᆠ㡰 ෌� ᔴ 㦨҈ 㦨҈  㦨䁸 꾀矄犨├ ᨨ犨

 =   + (  - ᔴ )



和ᨨ� �犨�  ; 黨 ᆠ㡰 ᔴ � ᨨ   ᆠᆠ�ᨨ   泐 �鼀  �矄 ��

by q㦨ᔴ ҈et⏌t㡰 t㦨t q㦨ᔴ ҈e㡰 㡰 ᨨ犨 ᆠᨨ ᨨ 㡰 㦨

R

= ҈

҈  w LC

ᆠ㡰 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 ᨨ ᨨ� �  ᆠᨨ矄 꾀 ᨨᨨVRVC㦨 Þ



I t㡰㦨҈ e  = 䰘mA ᆠ㡰 ᨨ鼀⧤ 泐�鼀t

d q

҈



+ � ¥㡰



 ᆠ ᨨ�ᨨ  ᆠ㡰 �矄   ᆠᨨᆠ  矄犨

R + p v  L

I t㡰㦨҈ e L ⏌ R = ҈ e L

҈黨

CἘ=

  㦨桌 ᲼Q 㦨 = ᔼ ҈

t L I t㡰㦨᲼ᔼ 㡰ᔼ ¥㡰桌 e ⏌ R t

é ù ҈ R  + ê wL  ú Ἐ㡰 w C + C ë û 졠  矄ᨨ� � 犨 � ҈ wL = w C + C Ἐ㡰



 + p �㡰   졠  矄ᨨ� �犨 � 㦨� ҈� ´ ҈ = ҈A b㡰 I 㡰 = ҈� ´ ҈ I ¥㡰㦨

R

ᆠᨨ矄 f =

e

=

ᆠ㡰 ᨨ犨 ᆠᨨ





=





=



� +  +  㡰 ᨨ犨 ᆠᨨ 犨㡰 = 㦨 㦨      +   - ᔴ 㡰 +  - 㡰 犨ᨨ犨 ᆠᨨ  = � \ 㦨 졠 ᨨ犨 ᆠᨨ  � � 㡰 V Vrms  b㡰 I rms = rms = 2 Z æ ҈ ö R + ç ÷ è wC ø 꾀矄w� ᆠ矄矄Irms ᨨ盐�  盐� ᆠ矄矄 ᆠ  盐 �ᨨ犨矄 ��  䰘 b㡰 �鼀ᆠᨨ 矄 ᨨ R C ᆠ�ᆠ盐�t㦨Req Ceq �㡰 R҈R� 矄�矄 C҈C�  t҈㦨 졔҈㡰 졔㡰㦨҈Ҙ矄 ��㡰 R҈R�  C҈C� 矄�矄 æ  ´҈ ö æ  ´  ö  t = ç ÷ç ÷ = Ҙ矄 è  +҈ø è  +  ø 黨 ���㡰 R҈R�  C҈C�  æ  ´҈ ö t = ç ÷ ´  + 㡰 = Ҙ矄 è  +҈ ø

WWW.JEEBOOKS.IN

EBD_8341 PS-258



黨

Physics

㡰 ᨨ鼀e㦨E矄�  ҈t㡰\ w㦨҈ ᨨ鼀 ��  �  ᆠ盐   矄 鼀   ᆠ �矄�矄 RC ᆠ�ᆠ盐� X  f = C R p \ XC㦨R f㦨� 㦨  ҈ = R ÞRCw㦨҈ wC ҈ -҈ s \R㦨҈kWC㦨҈mF ᨨ RC㦨 ҈ 㡰 꾀㦨ᔼ鼀� 㦨

� ҈

꾀㦨¥ � � ҈ = = ᔼ鼀 㦨 Req  ⏌  





��㡰 ෌� 㝐盐盐� 盐ᆠ ᆠ㝐㦨�鼀 ҈㦨҈鼀҈㦨�㦨鼀㦨

҈ �   = = ҈꾀錐 ᔼ =  = = 꾀 ҈ �  ҈ 꾀  ᨨ    矄犨�ᆠ 矄  ᆠᨨ矄  矄�鼀盐 ᨨ盐矄泐   ᨨ 犨ᨨ├ ᨨ  泐   �矄 �� 矄   � 盐ᆠ 쟼㝐 㦨 � ᆠ矄� 鼀� �ᆠ �泐

ᔼ҈ =

҈ ҈ ҈ᔼ҈ +   ᔼ  + 㝐ᔼ҈ᔼ    ҈ ҈ = ´ ҈ ´҈- 㡰҈ + ´  ´҈- 㡰 ´    졔 �맔҈㡰맔҈맔 㦨 �졔졔҈㡰맔҈ \ ␔㦨��鼀  b 㡰 ᔼ졔ᔼ㦨ᔼ҈ \ ᔼ㦨ᔼ҈ᔼ \ ␔ = D =

҈鼀

W

鼀

W

҈W

҈ ҈ ҈ ù é ҈ ê R =  +  + ҈ = ҈ ú � ë eq û I 鼀 ҈ ҈ = ´ = \ I 鼀�

 � 㡰 L㦨�鼀㦨�맔҈錐I㦨҈꾀R㦨W

dl -  + RI = VQ dt Þ VP - VQ = � ´ ҈ - ´ ҈  +  - ҈ ´  㦨�졔㦨 㡰 ෌� ᨨ犨P㦨␔ᨨ�V = � P = Vm × I 鼀矄 × ᆠᨨ矄 f Þ  = � ´ I 鼀矄 ´  Þ I 鼀矄 =  꾀  矄� � P = I 鼀矄 R  I 鼀矄 㡰 × R = P Þ  ´ R =  Þ R = ҈W ᨨ犨 ᆠᨨ �矄

\  I =

Þ I=

- Rt ù - Rt ù é é Vê V ҈ - e  L ú - ê҈ - e L ú Rê ú Rê ú ë û ë û

- Rt ù é - Rt Vê L e - e L ú ú Rê ë û L

R

VP - L

҈

ᆠᨨ矄 f = Þ  =

҈  + X L



Þ XL =

æ ҈ ö -҈ + ç Þ X L = 䰘�W è  ÷ø

␔   ᨨ犨 ᆠᨨ �矄 盐 �泐 ҈ = 䰘� X C = X L = 䰘� Þ wC ҈ ҈ F ÞC= = 䰘� ´ p ´ � 䰘�p æ ҈ ҈ö  = ´ ÷ mF = mF  ç p è � p ø N㦨



V

V

I

dI = dt

ᨨᔼ鼀 

- Rt - Rt ù é V ê -R L æ - R ö L ú \ -ç = e ÷e R ëê L è L ø ûú - Rt

L ҈ æ Rö   \ t= Þ ç ÷ t =   R  è L ø

�矄�矄 �鼀犨  ᔼ�矄鼀 �鼀盐鼀 盐� � �矄盐ᨨ �鼀� ⼄ �㡰 \ e L =



æ ҈ ö Þ ҈  + X L = ç è  ÷ø

L

R

I

R

R + X L ҈

 �㡰



-R æ L ö öù é - R æ L ç l ÷ V ê L çè R l  ÷ø L è R øú e e 盐 ᔼ鼀 ú Rê êë úû V é҈ ҈ù V Þ I 鼀 = ê - ú = R ë   û R  bᆠ㡰  ⼄盐 ᆠ泐犨 �ᆠ  ᆠ盐 �矄�  矄犨�   ᨨ� �矄 矄ᨨ  ᆠ ⼄盐 ᆠ泐

=

wr =

҈

=

҈

= ҈  矄 ҈ LC ҈ ´ ҈ - 㡰҈⏌

�矄 ⼄盐 ᆠ泐 �矄 �    ᨨ  ' ' -

꾀 w »   ᆠ盐  � =

V R  + w L -

҈  㡰 wC

WWW.JEEBOOKS.IN

PS-259

Alternating Current

�

� ᆠ盐   ᨨ盐�    ᆠ�ᆠ盐� 泐ᆠᨨ鼀矄 ᨨ If w>>wXL>XC矄ᨨᆠ�ᆠ盐� 矄�├ � 盐ᆠᨨ ᆠ㡰ᔼ鼀  ᆠᆠᨨ矄矄 AB, RC  ᨨ   ᆠ�ᆠ盐�

䰘



Z ҈҈ ҈ R p = \f㦨  矄 ᆠᨨ矄f㦨 = Z ҈҈    ᔼ  L㜠R ᆠ�ᆠ盐� ᨨ�  矄   ᆠ盐  ᔼ� 矄  ᨨ盐矄 㦨 

 V = Z҈ ҈  ᲼ 矄鼀 泐f҈桌 ҈ ҈ R = = 犨 ᆠᨨ矄f҈㦨 Þ q㦨�º Z҈ ҈   I҈㦨

A

(

҈00 W

I҈ 0.5 H

50 W

I O

 0V

ᔼ鼀  ᆠᆠᨨ矄矄 CDLR  ᨨ   ᆠ�ᆠ盐� 㦨 X L + R = wL㡰 + R 㦨 � ´҈㡰 + �㡰 = �  W

I

5º

0V

I

R � ҈ = = Þf = �º Z �   ᔴ盐 I ᨨ鼀 ᆠ�ᆠ盐�

犨  ᆠᨨ矄 f =



I =

R æR ö ҈ + R÷ ´ 졔҈졔㦨 졔r҈졔r è ø  

Req㦨 ç

R

A

B

R



r

R R

R

L

R

C

S

e+e e e = Þ I㦨 I 㦨 Req Req R ⏌ 㡰 + r҈ + r 矄�矄 ᆠἘ Ἐ ᨨ犨 �ᆠ ᨨ � �  ᆠᆠᨨ矄矄 泐 A�矄 ᨨ e r҈ eI r҈㦨 Þ e㦨 R ⏌ 㡰 + r҈ + r  Þ r҈㦨r졔R⏌ᨨR㦨 r҈ - r 㡰 

A

é d êE dt ê R ë

C



L

E R҈

R

G

F

dI df d = - ᲼ LI  桌 = - L  V㦨 dt dt dt 㦨 - L

I

B I

R - tù E éê ᨨ I  = ҈ - e L ú  R ê ú ë û 꾀矄ᨨ犨├ ᨨ犨  鼀 V㡰 ᨨ 盐ᆠ  ᆠᨨ矄矄   � 盐ᆠᨨ



+

㦨ᔼ҈졔ᔼ ; 꾀 꾀 ҈  �   꾀 ᨨ ��鼀ᆠᆠ�ᨨ犨� 盐泐ᆠ �   ᆠ ᨨ ᆠ盐 犨� ᨨ犨 ᨨ盐� ᆠᆠ�ᨨ  ᆠ盐 犨� ᨨ犨 ᨨ鼀 � 盐ᆠᨨ 盐矄 矄�矄 ᆠ ᆠᨨ矄矄 ᆠᆠ�ᨨ ᆠᨨ鼀矄 � � �   ᆠᨨ矄矄   � 盐ᆠᨨ ᆠᨨ鼀矄 ᨨ \

dI  - I  R =  dt 12V

5º

᲼ 矄鼀 泐f桌

\

t

෌� R҈㦨R㦨WE㦨҈V L㦨鼀

 ᆠ�ᆠ盐� ��  �矄   R㜠L ᆠ�ᆠ盐� �  犨 �ᆠ    ᆠ盐  �ᨨ犨矄 矄 矄ᨨᨨ  矄 ᆠ盐  �矄 矄犨�ᆠ   ᨨ  꾀泐� �⧤�ᆠ ᨨ 矄 犨�  ᨨᨨ꾀ᔴ ෌꾀 犨�矄� � ᨨ鼀෌鼀ᨨ� �ᆠᨨᆠ├犨�矄

E-L





 V = I㦨 Z  � 

I= I 矄� w t- p ⏌㡰

D

~



V = V 矄� w t

V

I

\

)

矄�  wt  p   ᆠ盐 �鼀� 矄 矄 ᨨ犨 ᨨ犨

B

C

V  =  A \ I㦨 rms

V㦨V鼀矄 

㦨 ҈㡰 + ҈㡰 = ҈ 

҈00 µ

V鼀矄㦨 n㦨� L㦨�鼀R㦨҈҈W

  ᔼ鼀  ᆠZ㦨 wL㡰 + R = ҈҈  W V 꾀矄ᨨᆠ盐 鼀�盐 I㦨 Z

æ ҈ ö  ҈㦨 X c + R҈ 㦨 ç ÷ + R҈ è wC ø

\

෌� 

D

- R ö ù æ t ç҈ - e L ÷ ú ç ÷ú è øû

R t - L V㦨E e

  ��矄�� 矄 ᨨ犨矄 ᨨᨨ矄��ᨨ

ᨨ  �ᨨ犨  ᨨ  ᆠ盐  -



t

\ V㦨 ҈ e  ´҈ - 㦨҈ e� ␔     矄犨�ᆠ  �矄 ᨨ    ᆠ盐  ᨨ犨矄  ᨨ盐�    ᆠ�ᆠ盐�ᔴ ᨨ 泐�   �ᆠ�ᨨ 矄 矄 ᨨ犨 �  ��盐 B C 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 I æ L dI ö = I R҈졔 R㡰 ç è dt ÷ø L R R R + dI æ ҈ ö \ dt = -ç ҈ è L ÷ø I \ 졠  � �� � R I dI R + R 㡰 t òI  I = - ҈ L  ò dt \

-

R҈ + R 㡰t L

F

D

WWW.JEEBOOKS.IN

I㦨I e

EBD_8341 PS-260

Physics

R + R  ҈ = L

+

��㡰 �ᨨ犨 ᨨ ᆠ盐 � LRᆠ�ᆠ盐�

= ҈

 ´ ҈-

R - tù I㦨I é êë҈ - e L úû

E ҈ = = 꾀 R҈ + R  I㦨e҈tAᆠᨨᆠ├犨�矄

 I㦨 \ 黨

꾀矄 犨├ ᨨ犨 �泐 U =

R é - tù I = I  ê҈ - e L ú  ê ú ë û -R R t - t ҈ ҈ Þ  = ҈ - e L  Þ e L =  

├� � ᨨ� ᨨ  ᨨ  矄� 矄

҈  L� � U µ �  

҈   ᨨ �矄 鼀 �鼀盐鼀 盐 犨   ᆠ盐  �矄  ᆠ    ᨨ �矄鼀 �鼀盐鼀盐 ᔼ L㜠R ᆠ�ᆠ盐� ⼄盐�ᨨ  ᨨ ᆠ盐  �ᨨ犨 �㦨� ҈e⏌tL㡰 �㦨㝐 �鼀盐鼀盐ᨨ ᆠ盐  ҈H = �s tL㦨 �鼀ᆠᨨ 矄 㦨L⏌R = W \ �㦨�⏌㦨� ҈e⏌�㡰 ҈ ҈ ᨨ = ҈  e t ⏌� Þ e t ⏌� =   æ ҈ö ᨨ⏌�㦨ᔼ  çè ÷ø Þ t ⏌ � = ᔼ ( ) = 黨  \ t = ( �)( 黨) ᨨr t = �s 㡰 �㡰 ␔   矄犨�ᆠ 和�矄�  ᨨ矄��ᨨ Ἐ҈Ἐ ᔼ  矄 泐矄 ᆠ盐   ᨨ盐�    ᆠᆠ�ᨨ �矄 ᨨ  犨� ᆠ 



R

F



G I

1W

A

C

҈V D E I

V

R W

矄� �⧤�ᆠ ᨨ 矄犨� ᨨᨨ꾀ᔴ෌꾀 졔 I맔҈졔I҈맔㦨 Þ I҈I㦨黨 꾀泐� �⧤�ᆠ ᨨ 矄犨� ᨨᨨ쟼 ෌ I҈졔҈ I҈졔I㡰㦨 Þ I҈졔I㦨

҈ ᨨ鼀⼄ �㡰  ��㡰I҈㦨 A 

\ ᨨ鼀 ��㡰I㦨҈A ᨨ � �  ᆠ 犨  A   B VA졔 ҈㡰맔㦨VB  Þ VAVB㦨�V ᨨ ᨨ 盐ᆠ�ᨨ  ᨨ  �  R҈ 

æ ҈ö  PR҈ = I҈ R҈ = ç ÷ ´  = �W è ø b㡰 �㡰␔   矄犨�ᆠ �矄 盐 �  ᨨ矄��ᨨ    

  ᆠ�ᆠ盐� �矄 矄 矄 ᨨ犨

ᨨ犨 ␔     矄 泐 矄 ᆠ盐  �矄 ᆠ    

 � 盐ᆠᨨ泐矄 ᨨᨨ �  ᆠ�ᆠ盐� E㦨I R졔R㡰

Þ

I=

E  = =  꾀 R + R �

R - t L

= ᨨ� e

҈ 

R L 黨 ´ ҈ ´҈- t = 黨 Þ t = 黨 = L R  + 㡰 犨  R㦨R졔R \t㦨҈맔҈矄 쟼 �泐矄ᨨ  泐  � 盐ᆠᨨ

Þ



E=

҈  ҈ æ  ö LI = ´ ҈ ´ ҈- ´ ç ÷  = � ´ ҈ -  è ø  

Topic-3 : Transformers and LC Oscillations



W

ᨨ�  e

m

E W

I҈졔I



I I =       矄 泐 盐  



␔  

B

҈

㡰 ␔   �矄 盐矄 �矄 �    ᨨ � ᆠᨨ矄矄 ᆠᆠ�ᨨ ҈ ö æ V t 㡰 = V� ç҈ - e RC ÷ è ø

꾀 t = �ms = � ´ ҈- s  �㡰

 ��㡰

҈m

�

 㡰

�´҈- æ ö  -黨 ҈ V t 㡰 = � ç ҈ - e ´҈ ´҈ ÷ = � ҈ - e -� 㡰 = V ç ÷ è ø

␔   ᨨ盐矄 �矄 �  ᆠᆠ�ᨨ 犨� �矄ᆠ � ᨨ犨V� 㦨鼀 矄 �矄ᆠ �� � ҈

V t 㡰 = e RC = e -� = ҈҈  ᨨ犨 ᨨ  �m矄

V t 㡰 =

҈ RC � - 䰘黨e

꾀 �m矄��  V t 㡰 = 䰘黨 ᨨ »    ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄

WWW.JEEBOOKS.IN

PS-261

Alternating Current 

ᆠ㡰 ᨨ犨ᨨ盐盐 ᔼ㡰㦨├␔

\  =



├␔ =  ᨨ矄 (҈꾀 )

b㡰 ␔   ᆠ �� � �矄 ᆠᨨ鼀   ᨨ � �  ᆠ 犨  ᆠᆠ�ᨨ矄犨�V  ᆠ �矄ᨨ �  �矄ᆠ矄犨�鼀 �鼀盐鼀 \Q㦨CV

é

\ ᔼ 盐 ᨨ� ᨨ 矄㜠 ᨨ犨   矄 ᨨ鼀

҈ ҈ = =    

V

� 盐㦨맔ᨨ盐盐㦨맔 㦨 꾀矄ᨨ



R

S

ᔼ҈ =

L 

 ´ ᔼ矄  Þ ᔼ矄 = 黨 ´ � = �꾀  ´ � 졠盐盐 ᆠ盐  㦨 �꾀 ᆠ㡰 ෌� 㦨矄㦨ᔼ㦨�꾀 㦨黨奠㦨黨 矄 Þ 矄 = 黨  쟼 �ᆠ� ᆠ泐 㦨黨 = 

㡰 ᔼ 矄  ᨨ盐矄 ᆠ � ᨨ  矄   泐�鼀 t 盐� � �矄ᆠ �� � Q� 矄㦨Qᆠᨨ矄wt \ ᔼ 矄  ᨨ盐矄 ᆠ盐 

Þ 黨 =





C

ᔼ҈   = ᔼ ҈

҈ ´ ҈ = �꾀   ᔼ b㡰 쟼 �ᆠ� ᆠ泐 h= ᨨ盐 = 矄 矄 � ᔼ \

- t ù

␔  t㦨tQ㦨CV êë҈ = e t úû 㦨ᔴ᲼҈桌

I� 矄 㦨

dQ = Q w 矄� wt dt 힘 C 졔

I

S

矄ᔼ矄㦨黨맔ᔼ Q㦨ᔼ㡰

ᔼ矄 =

黨 ´  ´ � = �꾀  \

Topic-4 : Miscellaneous Problems

҈

 æ ҈ ö ᆠ㡰ᔼ RC㜠ᆠ�ᆠ盐��鼀  ᆠ㦨 R + ç è WC ÷ø

Q㦨CV w㦨



 ᆠᆠ� ᆠ �  ᆠ矄  �矄 ᨨ盐 �鼀矄   ᆠᆠ� ᆠ�

ᆠ矄 꾀 \ᔼ鼀  ᆠ� ᆠ矄�矄矄矄   ᨨ ᆠ矄꾀 꾀㡰 ᨨ犨ᔼ㦨



VRA

�

VCA

᲼Q ᔼ �矄 � ᨨ � �  ᆠᆠᆠ矄矄 矄�矄 㜠ᔴ ᆠ�ᆠ盐�   V = 

VR

+ VC



꾀㜠矄錐㜠⼄矄錐ᔴ㜠⼄錐㜠⼄矄 ᨨ ᔴ ᆠ�ᆠ盐� �  矄 泐矄   ᆠ盐  I  ᨨ盐�    ᆠᆠ�ᨨ ᆠ㡰 �矄 ᨨ ᔼ  ᆠ矄 ᨨ  㜠ᔴ ᆠ�ᆠ盐�   ᨨ � �  ᆠ 㡰ᆠᨨ矄矄 � 盐ᆠᨨ 㡰�矄 ᨨ  ᆠᨨ矄矄  ᆠᆠ�ᨨ㦨� ᨨ � �  ᆠᔼ ᆠ矄ᨨ 㜠 ᆠ�ᆠ盐� 㦨 㡰 ᆠᨨ矄矄 � 盐ᆠᨨ 㡰 㦨 ᆠᨨ矄矄 㡰 㦨 � ᨨ� ᨨ 꾀ᔴ ᆠ�ᆠ盐� � 矄 泐矄 I鼀矄ᆠ盐  ᨨ犨矄 ᨨ盐�    ᆠᆠ�ᨨ ᆠ㡰 � 盐ᆠᨨ 㡰   㡰   矄�矄ᨨ 㡰  ᨨ � �  ᆠᆠᨨ矄矄 矄�矄ᨨ� 盐ᆠᨨ  ᆠᆠ�ᨨ I 꾀  ᨨ ᆠ  �� � ᆠ盐    ᨨ � �  ᆠ ᆠᨨ矄矄 㡰� 盐ᆠᨨ 㡰ᆠᆠ�ᨨ ᆠ㡰ᨨ矄�矄ᨨ 㡰µᔴ盐  ᔼ㡰



LC

I鼀 㦨CV맔

Þ Q㦨LC

> VCB

҈

҈ C 㦨V L LC ᆠ㡰 꾀泐� � ⧤�ᆠ ᨨ Ἐ矄 犨 Q dI Q dI = L -L =  Þ C dt C dt \

V \I RA < I RB  Z < VRB  Þ

L

I鼀 㦨Qw

d æ dQ ö d Q çè ÷ø = - LC  dt dt dt

㡰 和 盐  矄 ᨨ鼀

矄 矄 矄 ҈ Þ = = ҈    

\ 矄㦨 和 ᨨ犨  矄 ᨨ鼀 䰘

b㡰 ᨨ犨㦨맔ᔼ

 矄

=

 矄

㦨

  =  ҈

  ´ ҈ = 㦨҈�꾀 꾀  

ᨨ矄�矄 ᆠ㦨맔㦨W \ ᨨ犨  �矄矄� 矄   㦨 ᔼ  㦨 ҈�㡰 맔  㦨҈␔㦨҈├␔ ҈ ´ ҈ = 奠 \ 奠ᨨ矄矄㦨  Þ

ᔼ㦨

WWW.JEEBOOKS.IN

EBD_8341 Ps-262

Physics

Electromagnetic Waves

22

Topic-1 : Electromagnetic Waves, Conduction and Displacement Current ҈

㡰 �ᨨ 犨 ᆠ�ᆠ � E 鼀� �ᆠ � Bᨨ 

ᆠᨨ鼀� �ᆠ犨�矄�� 泐

E c㦨和 ᨨ �� 㡰 B Þ E = B ´ c = ҈ ´ ҈-䰘 ´  ´ ҈ =  c=

꾀矄  犨�矄 ᨨ�� � ᨨ � x㜠 �ᆠ�ᨨ  鼀� �ᆠ �  �矄 ᨨ � z㜠 �ᆠ�ᨨ

 r Eˆ ´ Bˆ 㡰  Cˆ \ E 矄 ᨨ盐 ᨨ �y㜠 �ᆠ�ᨨ  r r 和ᨨᆠ�ᆠ �  E = E 矄� E × x t 㡰

V = ᲼ - 矄� � ´ ҈ x + ҈� ´ ҈ t 㡰 ˆ 桌 m 



҈҈

ᆠ㡰 ᔼ ᆠᨨ鼀� �ᆠ犨



䰘

E =C B

qV E C

盐 �ᆠᨨ Cˆ �矄 �ᆠ盐ᨨᨨ  Eˆ   Bˆ

ur

E C

෌� V㦨҈ᔴ E㦨㡰 ҈ ´ ҈ -҈黨 ´ ҈ ´  ´ ҈ ´  = =  ´ ҈ -҈黨   ´  ҈ r 㡰 E = E xˆ + yˆ 㡰 矄� kz - wt 㡰 �ᆠ�ᨨ ᨨ ᨨ��ᨨ ᨨ  鼀犨 = + kˆ





 �ᆠ�ᨨ  ᨨ  ᆠᨨ鼀� �ᆠ 犨 �矄  �ᆠ盐 ᨨ ᨨ ᆠ�ᆠ 鼀� �ᆠ � 

\ kˆ = Eˆ ´ Bˆ æ �ˆ + ˆ ö ˆ -�ˆ + ˆ Þ kˆ = ç ÷ ´ B  Þ Bˆ =  è  ø r E \B = - xˆ + yˆ 㡰矄� kz - wt 㡰 c ˆ 㡰 ෌�  B =  ´ ҈- 矄� ᲼p y + ct 㡰桌�T - \ B =  ´ ҈ E = CB Þ E =  ´ ҈ ´  ´ ҈ - = 黨 ⏌鼀

黨

҈

E = c Þ E = Bc B  ÞE㦨�맔҈ 맔맔҈㦨҈�N⏌C r Þ E = ҈��ˆ Vr ⏌ m b㡰 ෌�  B =  ´ ҈ - 矄� ҈ ´ ҈ x +  ´ ҈҈ 㡰 矄� � E = B ´ C =  ´ ҈  ´  ´ ҈ = 黨 V⏌m \ 쟼ᆠ�ᆠ �  r  E = 黨矄� ҈ ´ ҈ x +  ´ ҈҈ t 㡰 ├ˆ V ⏌m

҈҈

ᆠ㡰 꾀t㦨z㦨

\

E ´ B 㡰  C Bˆ = �ˆ   Cˆ = - ˆ \ Eˆ = - kˆ \ E = E 矄� ᲼p y + ct 㡰桌 - kˆ㡰 ⏌鼀 ᨨ E = -黨矄� ᲼p y + ct 㡰桌kˆ ⏌鼀

ᔼ  矄ᆠ �矄矄  c =

E  c

 m 㦨 矄ᨨ盐 鼀��泐 e 㦨 矄ᨨ盐 鼀���泐

\ B =

E E = = E m  e  c ҈⏌ m  e 

r E E E =  �ˆ + ˆ 㡰 ᆠᨨ矄᲼ p 桌 =   �ˆ + ˆ 㡰  

ᨨᆠ 盐ᨨ ᆠ�ᆠ � 犨��    �ᆠ�ᨨ 

҈ m e

p k

r r FE = qE

ᆠ㡰 �ᨨ  犨  ᆠ�ᆠ �   鼀� �ᆠ �  ᨨ 

ᆠᨨ鼀� �ᆠ犨� ᆠ盐盐鼀�矄 B =

kˆ �ˆ + ˆ �ˆ + ˆ Þ Cˆ = ҈ =   

㡰 �ᆠ�ᨨ  ᨨ  ᨨ�矄�ᨨ  㦨 Eˆ = kˆ $ $ µ´B µ = �+  �ᆠ�ᨨ  ᨨ  ᨨ��ᨨ  㦨 E  ˆ-  r r � 盐 EB =  \ Bˆ =  㡰 꾀鼀�盐 ᨨ ᆠ�ᆠ �  E㡰 㝐� �ᆠ �  B㡰ᨨ 

ᆠᨨ鼀� �ᆠ犨 泐 �ᨨ

�ᆠ�ᨨ ᨨ  犨 ᨨ��ᨨ

�

ur

෌�  E = k$  B = $� -  $ �ˆ ˆ ҈   \  Cˆ = Eˆ ´ Bˆ =  ҈ -҈

�ˆ + ˆ  �ᆠᨨ�   �ᆠ�ᨨ ᨨ ᆠ�ᆠ �  Eˆ =



\ B =  ´ p ´ ҈ -䰘 ´ ҈ ´ ҈ - = ҈ ´ ҈ -黨 㦨҈

㡰 쟼ᆠᨨ鼀� �ᆠ 犨 犨� ᨨ�  �ᆠ盐 ᨨ   �ᆠ�ᨨ ᨨ 쟼ᆠ�ᆠ  㝐� �ᆠ � 矄

Cˆ = Eˆ ´ Bˆ

\㝐 �鼀盐鼀盐ᨨ 鼀� �ᆠ �  B =

F鼀 = qVB鼀 矄� 黨° =



꾀矄 ᆠᨨ鼀� �ᆠ犨�矄ᨨ�� �ᨨ �x �ᆠ�ᨨ  ᆠ�ᆠ � �矄ᨨ �y �ᆠ�ᨨ  \ Erˆ ´ Bˆ  Cˆ   Cˆ 㦨 �ᆠ�ᨨ ᨨ ᨨ��ᨨ ᨨ 犨㡰 \ B 矄 ᨨ盐 �  kˆ  �ᆠ�ᨨ  \ 㦨 쟼  m e ᆠᨨ矄 w├ 㡰 ├ˆ 꾀㦨 㦨 쟼  m e ᆠᨨ矄 ├ 㡰 ├ˆ ҈ B b㡰 쟼 �泐  矄�泐 = Þ B =  ´ m  ´ 쟼 �泐  矄�泐  m ҈ m  =  =  p ´ ҈ -䰘 C e

҈

- �ˆ + ˆ 㡰

ᨨᆠ 盐 ᨨ鼀� �ᆠ � �矄 �  �ᆠ�ᨨ

r r r r r q v ´ B㡰   v  k   ᨨ � �矄 ᨨ E  r r r �ˆ + ˆ Þ F  = FE + FB �矄  �ᨨ  ˆ + kˆ ˆ +  kˆ   ᆠ㡰 Sˆ = = �  + 



WWW.JEEBOOKS.IN

PS-263

Electromagnetic Waves ҈

E  = C  ´ ҈ 㦨맔҈ 㦨맔҈䰘

w pf p ´ 黨 ´ ҈黨 = K㦨 = 㦨� v v  ´ ҈

҈  ��㡰 ├ Î m  �� � �⼄盐�ᨨ  �㡰泐 ��㡰犨� ᔴ \ = ├=

 ҈ ҈ Î 쟼ᔴ 㦨 �  矄�泐㦨 Î ├쟼     ᔼ 鼀 �盐鼀  =

b㡰 B㦨

®

 ᨨ B = B 矄� kz - wt 㡰

㦨맔҈䰘 矄� � ´ ҈ z - ҈� ´ ҈҈҈ t 㡰� ҈

ᔴᨨ矄ᨨ � �泐

҈�

\ 쟼 ᔴ = ├쟼  

쟼 쟼 㡰 = ᔴ Þ  = ᔴ  r ෌�    쟼 = 쟼  ᆠᨨ矄 ├ 㡰 ᆠᨨ矄 w 㡰 �ˆ r 쟼 쟼 =  éëᆠᨨ矄 ( ├  w ) ˆ�  ᆠᨨ矄 ( ├ + w ) �ˆùû  r   =  éëᆠᨨ矄 ( ├  w ) ˆ  ᆠᨨ矄 ( ├ + w ) ˆùû  r  = ´ 矄� ├ 矄� w  r æ쟼 ö  = ç  矄� ├ 矄� w ÷ ˆ è ᔴ ø I ᆠ㡰 矄矄盐 P = C F I IA Dp I Þ =  Þ F = Þ Dp = ADt = A C C Dt C � ´ �㡰 ´ ҈ ´ ҈ ´  ´  㜠矄 =  ´ ҈



Þ

҈䰘

҈





r 쟼  ˆ = ᔴˆ = = ҈ ´ ҈-   쟼ˆ ´    = ᔴ  ´ ҈ ˆ = �ˆ [Q EM 犨矄ᨨ �졔 㡰x㜠 �ᆠ�ᨨ 桌 ˆ ´  r ˆ \  ˆ = ├ˆ ᨨ  = ҈ ´ ҈  ├

IA b㡰 F = ҈ + r 㡰 C ҈ + �㡰 ´ � ´ ҈ ;  ´ ҈-  =   ´ ҈ 㡰 �ᨨ  犨 鼀�盐 矄ᨨ ᆠ�ᆠ  鼀� �ᆠ � �  矄ᆠ �矄��  泐

�

uur uur

uur

uur

 ᨨ �ᆠ�ᨨ ᨨ  E ® ( - �ˆ +  ˆ )

҈

  · ᔴ Þ  = ᔼҘ Ҙ  ᔴ  ᔼҘ ҈ p ´ ҈-䰘 ´ = ; 맔҈

Þ 鼀矄 = ᔴ  ´ ҈ ␔ �ᆠ �矄ᆠᨨ矄矄ᨨ҈ ᆠ㡰 矄 ᨨ ᆠᨨ鼀� �ᆠ犨�  矄ᆠ�矄�� 泐 ҈ ᔴ=  �㡰 m Î

㡰 ᔼ =





(

)(

)

ᆠ㡰 ᨨᆠ�泐ᨨ 쟼㝐犨 �矄��  泐 v =

�ˆ + ├ˆ = ᆠˆ �

҈ mÎ

w =C k C ᨨᆠ�泐� 鼀 �盐鼀㦨  m҈㦨m㦨҈矄鼀 �盐鼀�矄 ᨨ 㜠鼀� �ᆠ ҈ Îr҈ ҈ Îr҈ C \ = = = Þ ҈ C æ ö Îr  ç ÷ Îr è  ø

ᨨ - K Þ E ´ �ˆ + ˆ 㡰



b㡰 矄� � ᨨ鼀盐쟼㦨맔ᔴ 㦨҈맔҈맔맔҈ 㦨맔҈ ⏌ᔴ  犨 矄矄盐鼀    㦨҈맔҈�矄�  矄 㡰盐 �矄 r b㡰 쟼 = ҈ˆᆠᨨ矄 éë �ˆ + ├ˆ  �ˆ + ├ˆ ùû

ᨨᆠ�泐� �㦨

꾀矄ᨨ S Þ E ´ B

uur

҈ ´ 黨 ´ ҈ ҈ ´ 쟼  ´  ´ ҈ 

( ├ˆ  �ˆ ) ᆠᨨ矄 (  +  ҈ᆠ )

\ 鼀� �ᆠ � ᆠᨨ鼀ᨨ  犨�ᨨ �z �ᆠ�ᨨ  ᆠ㡰 쟼㦨ᆠ㦨맔҈맔҈맔҈ 㦨맔҈⏌鼀

uur

=

犨矄  � �ᆠ�ᨨ ᨨ �ᆠ �ˆ + ├ˆ ᔴˆ ´ 쟼ˆ = � r 쟼 ҈ = =  ᔴ ᔴ r ҈ æ �ˆ + ├ˆ ö æ �ˆ + ├ˆ ö \ ç = ÷÷ çç ᔴ ÷÷ ᔴ çè � ø è ø r ҈ ᨨ鼀� �ᆠ �   (    ) = ᔴ

B =

҈黨

҈ ´҈



r r 㦨 ҈ ˆᆠᨨ矄 éë ⧤   ùû 쟼 ҈ ˆ㡰 r ˆ  �ᆠ�ᨨ  ᨨ \ ⧤ = �ˆ + ⧤錐

㦨�맔҈ 㜠矄 b㡰 꾀矄 r犨 ├ ᨨ犨

E  = =  ´ ҈ - T c  ´ ҈ ᨨ��ᨨ  �ᆠ�ᨨ  = Eˆ ´ Bˆ �ˆ = ˆ ´ Bˆ Þ Bˆ = kˆ

䰘 ´ ҈ 

Þ 쟼  =  ´҈ ├ ⏌ 鼀 =҈├ ⏌ 鼀



҈

쟼  ├  쟼  = = Þ =

쟼 ᔴ

쟼 矄�鼀�泐  ᔴ    ҈ = Þ = m  m  

㡰 쟼㝐 犨 �  矄�泐 ᨨ犨 ҈ = e  쟼ᆠ Þ ᔼ = 꾀  ᲼犨 쟼㦨鼀 �鼀盐鼀ᆠ�ᆠ � 桌 Þ



㡰 꾀� �泐  矄�泐ᨨ  鼀� �ᆠ � 

盐 =



m 



WWW.JEEBOOKS.IN

EBD_8341 Ps-264

Physics

꾀�  �泐  矄�泐 ᨨ  ᆠ�ᆠ �  e 쟼 盐쟼 =    ҈ ᨨ犨쟼㦨ᔴ ᔴ㦨 m  Î e  ҈ e   ´  =  = 盐  盐쟼 㦨  ´ ᔴ    = ´  m  e m   \ 盐쟼㦨盐 和� ᆠ  �泐  矄�泐ᨨ  ᆠ�ᆠ   鼀� �ᆠ �  �矄矄鼀 矄ᨨ  �泐矄矄ᨨᆠ� 犨� ⼄盐ᨨ盐鼀犨�⼄盐� 盐쟼㦨盐 䰘

ˆ ´ ˆ 矄 ᨨ盐 ��  �ᆠ�ᨨ ᨨ 犨ᨨ��ᨨ

ᆠ㡰 쟼 ˆ ˆ ˆ ˆ ˆ ˆ ˆ ) æ ˆ ˆö ˆ ˆ P�´Þ⧤ ˆ ´ � +  =  - - �㡰 = � +  P � +  Þ ⧤´ ç ÷     è ø 졠�ᨨ  㡰 ᨨ�ᨨ  㡰   ᨨ�ᨨ  㡰 ᨨ矄 ᨨ 矄�矄 泐 ˆ� + ˆ   ᆠ㡰 ෌� 쟼ᆠ�ᆠ � ᆠᨨ鼀ᨨ  ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ ��ᨨ 

ˆ 矄 ᨨ盐 ᨨ � ␔ᨨ��ᨨ ᆠᨨ ⧤



ᨨ 쟼  =





҈

쟼ᆠ矄矄

 �㡰  

├ 矄� ├ 矄� w w

�

␔矄ᨨ├ ᨨ犨   쟼 w = =ᆠ  ├ 㝐� �ᆠ �  ᆠᨨ

r 쟼  ˆ 矄� ├ 矄� w = ᆠ



㡰 ␔� 㜠 �ᆠ�ᨨ 鼀 矄쟼 矄 ᨨ盐  盐 ᆠ�ᨨ ᨨ   

҈



uur ur uur ur b㡰 꾀矄 犨 ├ ᨨ犨 E  B =  Q  ᲼ E ^ B 桌 uur ur   E ´ B  矄 ᨨ盐   ᨨ �  �ᆠ�ᨨ

꾀矄 $�   $ 㡰 ´ $�   $ 㡰 = � k$  ᆠ ᨨ�ᨨ  㡰 �矄   ᆠᨨᆠ  矄犨 ҈ ᆠ㡰 E㦨CB  C = m e ҈  쟼ᆠ�ᆠ �泐  矄�泐㦨 e E = m E  ҈ Bᨨ  = mB 㝐� �ᆠ  �泐  矄�泐㦨  m

盐矄mE㦨mB 쟼 �泐�矄⼄盐泐 ��  犨 ᆠ�ᆠ 鼀� �ᆠ �  b㡰 ␔ � ᨨ 鼀ᨨ ᨨᆠ ᨨ鼀�ᆠ� ��  㦨��맔҈�ᆠ鼀 ҈ ´ (  ⏌҈ ) ᨨ犨  ␔鼀 - ᔼ  矄�泐ᔼ㦨 㦨 㦨  꾀 ҈ p p ( � ) ᨨ犨  ᨨ  �矄�  矄�泐 ᔼ㡰ᨨ �矄ᨨᆠ�ᆠ �    ᨨ  ᨨ鼀� �ᆠ �   ᨨ ᔼ ҈ = e 쟼  ᔴ  

ᆠ㡰

g㜠泐矄㜠泐矄盐㜠泐矄 �矄�泐矄 ᔼ 泐矄  �ᨨ ᔼ෌Ӹ졠 㝐�ᆠᨨ犨矄 犨矄

 �ᨨ犨泐ᨨ犨 ��  盐��  㜠泐矄 ᔼ ᆠ矄� �ᨨ ᨨ  �泐㡰 ᆠ㡰 㝐�ᆠᨨ犨ᨨ  ᆠ矄ᨨ  � ᆠ�ᨨ ��� ���ᨨ   �泐ᨨ犨 鼀ᨨᆠ盐矄 ᆠ㡰 ෌鼀鼀 泐矄  㜠泐矄   �ᨨ  �矄� 泐矄  ᔼ   泐矄  㝐�ᆠᨨ犨矄   �ᨨ 犨矄 㡰 쟼 = Þ l =

) ) ) ) 泐- ^ 泐+



b㡰 ᨨ 泐 �鼀 ᨨ  �  矄ᨨ 쟼㝐 犨�

ᆠ矄� �ᨨ ᨨ 犨 �  �矄矄 ᨨᨨ犨矄

l  �ᨨ犨矄 > l 鼀�ᆠᨨ犨矄 > l �矄� > l 㜠泐矄



 = +쟼  ├ 矄� ├ ò ᆠᨨ矄 w 

黨

)

Topic-2 : Electromagnetic Spectrum

㝐� �ᆠ � �矄�� 泐

= +쟼 

æ  ö p÷ ´ç  è ҈ ø 㦨 ´  㦨 䰘 㦨 æ ö ҈ �  ´ ´  ҈ ç ÷ è p´ 黨 ´ ҈黨 ø \ 쟼㦨⏌鼀 b㡰 ᨨ鼀 ⼄盐矄�ᨨ  B㦨nT㦨맔҈黨T 鼀矄҈㡰 Qᨨᆠ�泐ᨨ �� � ᆠ盐盐鼀C㦨맔҈ r r r E = B ´ C r r r  E =  B  × C =  ´҈ -黨 ´  ´҈ 㦨⏌鼀 b㡰

(

r 쟼㡰 = 쟼ˆ� ᆠᨨ矄├ ᆠᨨ矄 w

쟼  ␔├ ᨨ犨  =  쟼  = -쟼  ├ 矄� ├ ᆠᨨ矄 w  =  㦨졔쟼├矄� ├ ᆠᨨ矄w  ᔼ �� �⼄  �㡰犨 

ᔼ e ᔴ

䰘



黨 ҈

ᆠ ᆠ Þ l = l 쟼  ´҈- ´  ´҈

҈҈´҈ ´҈ ´҈-҈黨

ᔼ ᆠ矄� �ᨨ ᨨ  ⼄盐 ᆠ泐

㜠泐矄 盐㜠泐矄 �矄� ᔼ  㦨҈处 犨 �  �ᨨ �矄���ᨨ �矄处ᨨ䰘处 㡰 쟼 �泐矄⼄盐 ᆠᨨ  ��ᨨ 矄�矄

Eg 㜠 泐矄 > E㜠 泐矄 > E鼀�ᆠᨨ犨 > E꾀㝐  �ᨨ犨矄 \ l g 㜠 泐矄 < l 㜠 泐矄 < l 鼀�ᆠᨨ犨 < l 꾀㝐  �ᨨ犨矄

ᨨ鼀 ᨨ矄⼄盐 ᆠ犨  㡰 㝐�ᆠᨨ犨 ® ҈- 鼀  �㡰 㡰 ෌鼀鼀 泐矄 ® ҈-҈� 鼀  ��㡰 ᆠ㡰 꾀㝐  �ᨨ 犨 ® ҈ 鼀  �㡰 㡰 㜠 泐矄 ® ҈-҈ 鼀  ���㡰 ᆠ㡰 졠�ᆠ �ᔴᨨ鼀鼀盐 �ᆠ�ᨨ  ᔼ  ��     �ᨨ␔矄 和ᨨ  矄ᨨ盐 㝐ᨨ�  ᨨ 矄  㝐�ᆠᨨ犨矄 㡰 ҈㡰 ᔼ  泐矄盐矄 ᨨ鼀盐矄ᆠ盐矄� ᆠ盐矄 矄   泐矄 㡰  �ᨨ犨矄盐矄  ᨨᨨ ᆠ矄� �ᆠ盐矄 矄犨矄 泐ᨨ �犨 �  �� � ᨨ鼀 犨ᆠ �鼀矄ᨨ 犨 盐   ├�ᨨ鼀矄 㡰 㜠泐矄  盐矄  ᨨ ᆠ ᆠ盐 ᨨ  ᨨ 矄 ᆠ盐矄  泐  ��   � � ᨨ犨 盐  泐 ᆠ Ἐ    ᨨ盐�  矄鼀 �盐鼀�├ ᨨ 矄 㡰 �ᨨ 泐矄  矄ᨨ  泐ᨨ ᨨ  ᨨ    鼀ᨨ矄  㡰 ␔ � 鼀� 泐ᨨ鼀�ᆠ 泐 ᨨ� � � 矄矄ᆠ 㜠 ᨨ 矄 ᨨ �ᨨ犨ᨨ ᆠᨨ鼀� �ᆠ矄ᆠ盐鼀 ᨨ盐 ᨨ  矄ᨨ �盐鼀 㜠�矄�  ��ᨨ  㡰 ��ᨨ ᨨ ᨨ鼀矄 鼀ᨨᆠ盐矄䰘 鼀ᨨ҈鼀鼀  �ᨨᆠ� ᆠ泐ᨨ   盐ᆠ盐矄҈ 鼀 㝐� ᨨ ҈鼀鼀ᨨ҈鼀

WWW.JEEBOOKS.IN

P-265

Ray Optics and Optical Instruments

Ray Optics and Optical Instruments

23

Topic-1 : Plane Mirror, Spherical Mirror and Reflection of Light ҈



㡰 졠ᆠ�矄ᆠ 泐ᨨ  �盐矄ᨨ ᆠ盐盐 R㡰ᨨ ᆠᨨ ᆠ 鼀�ᨨ  ᆠ �鼀� ᨨ鼀  �矄  �     �鼀� �矄   ᨨ 盐 鼀� � � 

ᔼ鼀�  =

h C h�

O

F ᔼ鼀�

P

䰘

h� < h 

␔  ᨨᆠ�矄ᆠ鼀 ´ 盐 �´  ᔼ鼀� ҈ = ᆠ鼀 = =盐 - -�  ␔  ᨨᆠ�矄҈ᆠ鼀 ᆠ㡰

´ 盐 � ´ ҈  = =ᆠ鼀 盐 - ҈ - � 䰘

  ҈ 和�ᨨ  = ҈ -  = ᆠ鼀 =  䰘 ҈ 和ᨨ꾀ᔴ ᆠᨨᆠ矄鼀 矄 ᆠ㡰 ᔴᨨ   鼀ᨨᨨ �矄 盐矄  矄  矄 � � 鼀�ᨨ 졠



v ᆠ㡰 +� = - Þ v = -�u u ҈ ҈ ҈ ҈ ҈ ҈ + = 矄� � + = ᨨ v u f -�u u 

҈ᆠ鼀

\ 盐㦨鼀 ᨨ鼀 ⼄盐矄�ᨨ   v 㦨 ҈� ᆠ鼀 u 㦨  ҈ ᆠ鼀  �盐矄 ᨨ  ᆠ盐盐 R 㦨 f 㦨 䁸 ҈ ҈ ҈ 矄� � 鼀�ᨨ ᨨ鼀盐 + = v u f

 



和



ᆠ㡰

  



ᨨ �矄 ᆠ = 



  + =   

b㡰 M1

q

ᨨ鼀 ��盐  �㦨

黨 O

q

q 턼

M2

 �犨  犨ᨨ鼀�ᨨ矄q 泐턼 P 鼀�ᨨ㝐҈  矄 P 鼀�ᨨ㝐 \ 㝐҈ 矄㦨Ð졠 턼㦨Ð㝐҈졠㝐㦨 q 和�鼀�泐 Ð㝐턼㦨 Ð졠턼 㦨Ð㝐졠㝐҈㦨 q

�

҈⏌

=

҈





ᔼ D졠 턼q㦨҈ Þq㦨

ᆠ㡰

矄� �鼀�ᨨ ᨨ鼀盐鼀� � �ᆠ�ᨨ �矄�� 泐

҈ f = u  f ҈ u f 꾀 ᨨᆠ盐矄 鼀� � �ᆠ�ᨨ  �矄 ¥ 꾀 u㦨f 鼀� � �ᆠ�ᨨ �矄҈  ᆠ �  㡰 ᆠᨨᆠ泐 �ᆠ矄 �m 矄盐矄 �矄 ᆠ ᨨ ᨨᆠ�x� 

b㡰 꾀矄矄 ᨨ犨 �   ��盐犨   ᨨᆠ O㡰�矄ᆠ 犨

F C �鼀� I㡰�矄 ᨨ鼀 泐ᨨ Cᔼ�矄�  �矄ᆠᨨ ��ᨨ   犨   矄盐  矄 � 矄 �矄泐矄ᨨ犨 矄  �鼀�矄ᨨ  �� ᨨ  ᨨᆠ� 졠ᆠ졠�矄犨  ᨨᆠ盐矄 f 㡰 ᆠ  ᨨ ᆠ盐盐 f㡰f xf 㝐ᨨ鼀 ᨨ犨 矄 

F

҈ 㦨 

\

m=

҈ � 

⏌  \ �㦨  꾀 �ᨨ � ᆠ�  ᆠ㡰

 q

҈ ҈ ҈ + =  Þ  f 㦨   ᆠ鼀 ҈� -҈㡰 f

 ᨨ  �盐矄 ᨨ  ᆠ盐盐 R 㦨 f 㦨   ᆠ鼀 㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ 泐 ᨨ  ��  �矄 � � �

҈ ᨨ鼀 � +   㡰  �ᆠ�ᨨ  � ᆠ�    ᔼ ᆠ�   � ᨨ  鼀�ᨨ 泐



q



҈�ᆠ鼀

I

҈

C

P

O

V

㡰 泐 ��鼀�矄矄 ᨨᨨ犨矄 ᨨ鼀 ��盐WX㦨PQ㦨d

d ZS㦨RS 㦨 

Q

PW㦨PS

\

d VW㦨RS㦨 㦨d 

P

q

R q S

d

W

Z 턼

X

T L

U

和�鼀�泐 XY㦨d \ VY 㦨VW졔WX졔XY㦨d졔d졔d㦨d

L

Y

WWW.JEEBOOKS.IN

EBD_8341 P-266

҈҈

㡰 \

Physics ᨨ鼀鼀�ᨨ ᨨ鼀盐

҈ ҈ ҈ dv du ᨨ鼀鼀�ᨨ ᨨ鼀盐 + = \ = v u f v u    æ f ö dv - v  æ f ö =  = -ç Þdv㦨 çè  - f ÷ø dx ÷ du u èu- f ø 

æ f ö ᔼ鼀�矄� 㦨 ç 맔b è u - f ø÷ 㡰 矄� �鼀�ᨨ ᨨ鼀盐 ᨨ �矄ᨨ矄��ᨨ

� æ Rö ᆠ鼀 f = +҈ᆠ鼀 ç = ÷ u҈ = 䁸 v҈ = è ø  ҈ ҈ ҈  ҈ ҈ + = + = v҈ u҈ f  � u҈ ҈ \u҈㦨�鼀 矄� �鼀�ᨨ ᨨ鼀盐 ᨨh矄ᆠᨨ ᨨ矄��ᨨ

\

҈

u㦨䁸v㦨

҈

҈

҈

҈ ҈ ҈ + = v u f u v盐矄ᨨ ᨨ�ᨨ 矄 㡰  㡰鼀ᆠ 犨�  鼀�ᨨ ᨨ鼀盐 ␔ 矄ᨨ�ᨨ  ᆠ㡰  㡰 ᨨ ᨨ鼀ᆠ 犨� 鼀�ᨨ ᨨ鼀盐 ᨨ 㡰

꾀泐� � 鼀�ᨨ ᨨ鼀盐

Þ

�  f㦨҈ᆠ鼀 䰘

҈ ҈ ҈ 䰘 ҈ ҈ ҈ ҈ 䰘 + = Þ + = Þ = v u  f � u  ҈ u ҈ � u㦨�鼀 u҈ - u � ҈ ´ =  ├鼀 -҈ 和 ᨨ ᨨᆠ㦨 㦨 �鼀  � ҈㡰 �矄 ᆠᨨ ᨨᆠu㦨ᆠ鼀 �矄 ᆠᨨ �鼀�v㦨҈ᆠ鼀 -v -҈㡰 ҈ = = 㝐� � �ᆠ�ᨨ  m =  u - ҈ 和 ᨨ �鼀�㦨m맔矄 ᨨ ᨨᆠ = ´ 黨 㦨҈ᆠ鼀矄҈ 黨 和� ᆠ   �鼀� ᨨ鼀  �矄    ᨨ �    ᨨᆠ �矄 犨  ᨨᆠ盐矄    ᆠ  ᨨ  ᆠ盐盐 ᔴ   矄�盐�ᨨ  �矄 矄 矄 ᨨ犨 �   ��盐和� ᆠ �鼀�ᨨ B�矄 ᨨ鼀 BἘ�矄

A

҈䰘

f⏌

҈ ҈ ҈ Þv㦨䰘 + = v -䰘 -

矄ᨨ盐ᨨ�矄黨䰘㦨犨 �ᆠ �矄�   ᆠ鼀 ᆠ㡰  ᨨ鼀盐 ᆠᨨ

ᆠ� �u v   f ᨨ  矄 �ᆠ 鼀�ᨨ

҈

㡰 꾀   

B�矄矄�盐  ᆠ ᨨ ᆠ盐盐 �矄 �矄 ᆠ ᨨ f ᨨ鼀 ᨨ

\



҈ ҈ ҈ ҈ ҈ ҈ + = Þ  + = -� f v - f u v f  ҈ ҈  \v㦨�f Þ =- + v f �f ᔼ鼀� � ᨨ ᨨ 㦨� f f㦨�f

�f v = 䁸 

ᨨ鼀 ᨨ鼀盐





t҈ t h h  h h + = + = =  m҈ m       ෌� 

ᆠ㡰

 ᆠ��   m =

 

 矄� q = ҈矄� 黨°   䰘 Þ 矄� q㦨 錐 ᆠᨨ矄 q =   和ᨨ�  �W㦨p ҈ᆠᨨ矄q㡰 = p ҈  䰘 ⏌ 㡰 ᆠ�ᨨ  ᨨ   �泐 矄鼀�



p ҈  ᆠᨨ矄 q㡰 ҈  䰘 ⏌  = = ҈䰘 p  ᆠ �ᨨ �� 鼀�矄ᨨ盐ᨨ 矄盐 ᆠ 㦨҈䰘맔҈㦨҈䰘奠 b㡰  ᨨ鼀 ⼄盐矄�ᨨ  � 鼀���泐 =

B

A



D=

v � f fù é \ 㝐� � �ᆠ�ᨨ  M = = = ҈� êG�ven u = ú û u f  ë 㡰 �矄 ᆠᨨ ᨨ� 꾀 ᨨ鼀 鼀�ᨨ�矄f⏌



m҈ =

m =  

f �f PA =  f - =  

盐矄 �  �鼀�ᨨ A ᨨᨨ� A u = -

҈�

v=-

҈ ҈ ҈ + =  �矄 �  ᨨ 泐 ᨨ 鼀�ᨨ矄 ᨨ  矄鼀盐矄 犨  u v f   矄�  ᨨ  盐 �矄 泐矄鼀矄 ᆠᨨ鼀  ᨨ    �盐矄 ᨨ ᆠ盐盐ᨨ  鼀�ᨨ 犨矄 ᨨ 鼀�ᨨ  �  ᨨ   矄犨 矄 � 矄 �ᆠ 矄盐 ᆠ矄 犨矄ᨨ  ᆠ�ᨨ � 犨   �� �矄  ᆠ  Topic-2 : Refraction of Light at Plane Surface and Total Internal Reflection

B

\

҈ ҈ ҈ ҈ ҈ - +  - = - = + = = v f u -   ´   ´ 

 ´  = -䰘䰘  盐 盐ᨨ v㦨 矄ᨨ盐ᨨ�矄䰘䰘㦨䰘ᆠ鼀 犨 �ᆠ �矄�  ᆠ鼀  ᨨ犨ᨨ � � � ᨨ 䰘黨㡰犨  u㦨䰘 

Þ

A'

B' P

҈ ҈ ҈ ҈  ҈ ҈ + = Þ = - = \ v㦨f v f ⏌ - f v f f f ᔼ鼀�A¢B¢ᨨ � AB矄 ᨨ盐 ᔼ� ᆠ� �矄ᔼ鼀�ᨨ F犨�  ᨨ鼀   � � �泐 꾀矄ᨨ ��  泐 ᨨ鼀 � � �泐ᨨᨨ犨 矄� � �泐矄鼀矄ᨨ  � ᆠ� �矄 ᨨ  鼀�ᨨ ᆠ 㡰 ෌� f㦨ᆠ鼀

F



er =

e =  Þ e =  e e

WWW.JEEBOOKS.IN

P-267

Ray Optics and Optical Instruments  m  � 鼀��泐 m r = m =  Þ m =  m  

矄� 꾀 矄� 黨° - 꾀㡰 矄� 꾀  矄� q ᔴ = ᆠᨨ矄 꾀

ᨨ鼀⼄  �㡰 矄� q ᔴ =

\ me = m e m  e v ҈ æ = = çQ c = c  çè me

ö ÷ m e  ÷ø ҈

 矄� q ᔴ =  꾀 黨

 ´ =  

n = mr er =



�

ᆠ㡰

҈ ҈ ҈  Þ 矄� qc = = n  矄� qc ᔴ��ᆠ �qᆠ㦨

Þ 矄� ᔴ =

æ  ö -҈ ç Ҙ  ÷ ᨨq鼀 㦨 矄� ç  - ҈ ÷ Ҙ ҈ è ø æ Ҙ ö -҈  ᨨT҈Rq 矄� ç  - ҈ ÷ ç Ҙ҈ ÷ è ø 㡰 ᨨ鼀 ��  ��盐 꾀矄矄� ᨨ㦨m 矄� ᨨ

҈





=

䰘



҈҈



  = ´ ҈�ᆠ鼀 䰘 䰘

n ҈҈�鼀鼀  q

P

҈҈�⏌

 n㦨 ᆠ��  ᨨ �⼄盐� ҈ + ҈҈�⏌㡰  ҈҈� ⏌  n = 䰘 ´ \n㦨҈ \   æ ҈҈� ö (҈) + ç ÷ è  ø 㡰 꾀 ᨨ� 꾀泐和 矄 犨 

矄� �° ҈ Þ 矄�  = … �㡰 矄�  m  꾀 ᨨ�   ᨨ ᨨ�    ᆠ�ᨨ  m=

 -

 ´҈ ´ ᆠᨨ q

矄� �҈ =

= �䰘䰘� » �䰘

 ´  ᆠ㡰 꾀矄奠 ᨨ ��  �矄 ᆠ  矄ᨨ ᨨ 泐 ҈   㦨 黨奠㡰 ᨨ �� ᆠᨨ鼀矄  ᆠ�ᨨ 矄ᨨ 黨 黨  ᆠ = ᔼ  Þ ⧤ 꾀  = ⧤҈꾀� ҈ ҈ 黨 ҈ 黨  ´ ´ 㡰 ҈꾀�  Þ 꾀  = Þ  꾀  = ҈  ҈    꾀 ´ 㡰 =  ҈ 㡰

m 矄� �  �㡰 = m  矄�  Q Ð� = 꾀  Ð = 黨° - 꾀㡰 m ␔矄ᨨ├ ᨨ犨  矄� qᔴ = m

ᨨ鼀和 Ἐ矄犨

 

ᆠ㡰

矄� q㦨

㡰 矄� �和 矄犨ᨨ  ᆠ�ᨨ  ҈맔矄�  㦨҈҈矄� q  Þ 矄� q = = 黨 » � ҈҈ Þq㦨 x㦨Ҙ鼀맔ᆠᨨq

 ´ ҈

䰘 㦨黨 ᨨ =

=

꾀泐� � 和 矄 犨  ᨨ�  P n҈矄� q㦨n矄� 黨

=  + 

\盐鼀ᨨ  ᆠ�ᨨ 矄 =



ᨨ

҈鼀鼀 n҈ q

졠�ᆠ   � 㦨 꾀졠 졔 m졠

=  + 㡰



+ ҈ 㦨黨 졔黨 

�⼄盐�

 = ᆠᨨ矄 ᨨ Þ 꾀졠 =  꾀졠   = ᆠᨨ矄 ᨨ Þ 졠 = 졠 



҈ = m

Þ

= 

矄� ᨨ



矄� 黨° =m 矄� ᔴ

-҈ 矄� �矄�  q鼀 㦨 Ҙ҈ Ҙ  - Ҙ҈ 㦨 Ҙ҈

Þm=





Ҙ

矄� ᨨ

 

㦨҈�ᆠ鼀 㦨䁸

꾀  n = \

㡰 ෌� Ҙ㦨

ᨨ꾀㦨 ҈ 矄� qᔴ㡰

ᔼ ᆠ�  泐  矄 꾀 꾀 Ҙ㡰 黨  Ҙ 㡰



҈ m

�

꾀�

ᨨ鼀 ��盐 �҈ = 黨° -  \ 矄� 黨° - 㡰 = Þ ᆠᨨ矄  =

҈ m

� 

҈ m

… ��㡰

ᨨ犨 ᆠᨨ矄  = ҈ - 矄�   = ҈ -

ᨨ鼀⼄矄 ��㡰  ���㡰

꾀 �҈ 黨 m

҈ = m

҈ m 

=

m  - ҈

… ���㡰

m 

m  - ҈ m 

和⼄盐� �ᨨ 矄� 矄   矄ᨨ� �犨� m =

 

WWW.JEEBOOKS.IN

EBD_8341 P-268

҈

Physics

ᆠ㡰  � �PᨨQ 꾀泐� �v u㦨 gh

v  -   =  ´ ҈ ´ 䰘 Þ v = ҈ 鼀⏌矄鼀 ᨨᆠ�泐ᨨ  矄 ᆠ�  泐 �矄



矄� �° � = 矄� �  꾀泐� � 和 Ἐ矄 犨  A 矄� � Ҙ ҈ Ҙ = = 矄� r҈ Ҙ҈ ҈ Ҙ= 

҈ v

 ´ ҈ = ҈ 鼀⏌矄 

v Ἐ = wm ´ v =

ᨨ鼀⼄ �㡰  ��㡰

u 㦨  g 㦨҈鼀⏌矄 h 㦨䰘鼀





꾀�

҈鼀



m

m

␔

 泐 

҈ q



泐 

B

㡰 �矄 ᆠᨨ �盐�鼀� ᨨ鼀矄盐 ᆠ㦨ᆠ鼀

泐矄ᆠᨨ鼀� � ᨨ鼀 ᨨ� ᨨᆠ ᨨ  �矄矄㜠��  ᆠ

ᨨ鼀泐   ᆠ矄矄盐 �   ᨨ� 犨ᆠ   ᨨ   ᆠ 泐矄ᆠ├犨 矄 �鼀�犨� ᨨ鼀    ᆠ  ᨨ 泐 b㡰 ᨨ鼀 矄 Ἐ矄犨 Ҙ� 矄� � = m a�r 矄� 黨°

b㡰

㝐 �鼀盐鼀 盐鼀ᨨ  ᆠ�ᨨ  =

犨 x㦨  = 

  x ҈黨



l㦨  x

m =

\ ҈䰘

30° 30°

㝐 �鼀盐鼀 盐鼀ᨨ  ᆠ�ᨨ 㦨

b㡰 ᨨ �鼀�ᨨ ᨨ�  P ᨨ    ᨨ  PQᨨ矄  泐  ᨨ矄�矄 ᨨ盐  ᨨ鼀  ᨨ�  Q ᔼ DQNS NS㦨QS㦨h \ ÐNQS㦨� Q \ r㦨� ᨨ犨� DQMA h ÐMQA㦨� \ MA㦨QA㦨h P 矄� r 矄� �° ҈ m= =  矄� � 矄� � ᔼ DPMB PM㦨h졔h㦨�h \

矄� � =

h

�h

=

҈ �

  ⏌ 

P qC n ҈

Q a

C

n n҈矄� qC㦨nᨨ 矄� qC =  n҈ 꾀泐� � 和 Ἐ矄 犨  Q n矄� a㦨n҈ᆠᨨ矄qC

r

2h

Þ



S 2h

ᨨ 

B h

n

黨 q C

B

M

A

D

꾀泐� �和 Ἐ矄犨  P ᆠ꾀ᨨ 矄

㦨 N

�

 ���㡰

m 㦨҈ \ m҈㦨m m҈ ᔼ    鼀�  泐�矄 ᨨ � ᆠ�   泐  � � 

盐鼀ᨨ �  ᆠ矄    ᆠ��  ᨨ   �矄   矄鼀 �盐鼀�矄犨泐矄矄鼀 � ᆠ�  泐�矄鼀 �盐鼀㜠҈졠꾀ᔴ鼀� 泐� 鼀 �盐鼀㜠 \m҈㦨m 㡰 ᨨ鼀   ��鼀   泐 犨� ᆠᨨ鼀 ᨨ盐 ᨨ鼀 CD �  � 矄盐 矄 ᨨ�   ᆠ�ᨨ  矄盐 ᆠ AD � � 矄�├矄   矄盐 ᆠADᆠ��ᆠ �qC  �鼀�� �ᆠ矄㡰 A

鼀

 ��㡰

\

҈ 矄� �

mg =

m =

矄� r m  = m 矄� � 㝐盐�泐� � ⼄ �㡰 ��㡰   ���㡰 m  m m  矄� � 矄� r҈ 矄� r ´ ´ = ´ ´ m҈ m  m 矄� r҈ 矄� r 矄� �

 ᆠ 



ᆠ�



  

 泐

泐 

҈

矄� r҈ m  = 矄� r m  꾀��  泐� �和 Ἐ矄 犨  C 

\

� C

꾀泐� � 和 Ἐ矄 犨  B



҈�

r2

B

O

␔

A

҈

 泐 

P 꾀�

O q q

ᆠ

A r҈

�҈

ᆠ㡰 � ᆠ�   泐�矄 泐 ᆠ    泐 ᆠ  ÐMOB㦨҈ q >Ð졠  �犨  ᆠ   ᆠ  泐 M

m D r



�矄

҈

 �㡰

ìï æ n ö üï n҈ ᆠᨨ矄 í矄� -҈ ç  ÷ ý n è n҈ ø þï ïî é æ n ö ïü ù n ïì a = 矄� -҈ ê ҈ ᆠᨨ矄 í矄� -҈ ç  ÷ ý ú è n҈ ø þï ûú îï ëê n 矄� a =

b㡰

n҈ n

 �㡰

 a⏌

a ⏌ ᔴ



졠Ἐ 

 ��㡰



꾀 a⏌

a⏌







WWW.JEEBOOKS.IN

P-269

Ray Optics and Optical Instruments

҈

� ᆠ�   鼀� 泐졠꾀ᔴ졠쟼 ᨨ �矄矄矄   ᨨ  �� ᆠ �鼀� 矄 矄鼀 㡰 꾀泐� � 和 Ἐ矄 犨

矄� r Ἐ 矄� 黨 - r 㡰 = ᲼Q � 㦨 r錐 r' 졔 r㦨黨 桌 矄� � 矄� r ᆠᨨ矄 r ҈ m= \  矄� r æ 矄� r ö æ҈ö ᔴ��ᆠ � qc = 矄� -҈ ç ÷ 㦨 矄� -҈ ç ÷ è ҈ ø è ᆠᨨ矄 r ø \qc㦨矄� ҈  r㡰 㡰 ⼄盐 ᆠy 㡰 ᨨ矄 ᨨᆠ  �犨� 鼀 �盐鼀 ෌矄矄 矄 �矄   ᨨ�ᆠ泐  矄 鼀 �盐鼀   ᨨᆠ�泐 ᨨ  ��  ᆠ矄矄   ᨨ 犨 � � �矄矄 ᆠ矄矄 㡰 n矄� q㦨 nmDn㡰矄� 黨 Þ n맔矄�  㦨᲼nm맔҈桌矄� 黨 \ ҈맔矄�  㦨҈m맔҈\m㦨 㡰 ᨨ   ᆠᨨ   矄 �ᆠ  ᆠ� � 矄盐 ᆠ � �㜠ᨨ� �  ᆠ 䰘 u㦨ᆠ鼀v㦨䁸u҈㦨҈m㦨  R㦨ᆠ鼀  -m҈ m  m  - m҈  + 㦨 u v R ᆠ鼀 ҈ 

  

\

m=

䰘 -҈ -҈ 䰘⏌   + = -㡰  v

䰘

Q

r' P



҈�

҈�㡰 ᨨ鼀 ��盐 矄� � =

҈� +  

C m=

҈� ҈� +  



= ҈ ´ 矄� �° =

r

ᆠ鼀

҈矄� ° =

҈

 矄� r  Þ 矄� r =  Þ r = °

ᨨ鼀�ᨨ鼀泐CP = CQ

\ r Ἐ = °

꾀��  泐矄 Ἐ矄 犨  Q



 矄� r Ἐ = ҈矄� e  Þ  = 矄� e Þ e = °

ᨨ鼀 �ᨨ鼀泐

r Ἐ+ q + e = ҈°  꾀矄 �矄�矄ᨨ 矄�� � 㡰 Þ ° + q + ° = ҈° Þ q = 黨° 

�㡰 ἘᔴἘ ᆠ��ᆠ � ҈�矄� ᔴ㦨҈矄� 黨 Þ

矄� ᔴ =

҈ ҈� B C

q

A

鼀 �盐鼀

꾀 꾀 꾀 ҈ \ = 꾀 ҈�

盐矄� ᔴ =

\

  矄� r = 矄� �°

꾀 =

҈� 꾀 ҈

ᔼ  犨 ᆠ꾀 泐 黨     ᨨ  �    泐��  㦨

҈� ´ 黨 = ҈鼀 ҈

҈

㝐 �鼀盐鼀�鼀├  泐泐ᨨ �  



=   ᔴ⏌  ҈ \ = = � ´ ҈ 矄 = � ´ ҈ -黨 矄  ´ ҈ ⏌ ҈�

� ҈�ᆠ鼀 P ҈�ᆠ鼀

ᆠ鼀

n D

黨鼀

=

҈�ᆠ鼀





꾀泐和 Ἐ矄 犨  P

ᨨ鼀和 Ἐ矄犨 m ´ 矄� � = ҈ ´ 矄� r

Þm´

e q S r' R  ᆠ 泐

r



ᨨ�

\ v㦨҈ᆠ鼀 V¢ ҈ᆠ鼀

�矄�鼀�犨� ᨨ 矄ᨨᆠ 犨 ᨨ   犨㜠ᨨ��  ᆠ I 䰘  u㦨҈ᆠ鼀v㦨v¢m҈㦨 m㦨  R㦨¥   -䰘   +  㦨 +҈ V ¢ \ V¢ 㦨҈ᆠ鼀

 ᨨ  �矄 ᆠᨨ  �鼀� ᨨ鼀 ᨨᨨ鼀ᨨ   ├ 㦨҈҈㦨ᆠ鼀 㡰 ᔼ   ��盐C㦨ᆠ��ᆠ �  R 졠㝐 R = ᔼ D졠㝐  C = 㝐  ᔴ ᔴ  ҈  ᔴᔴ Q 矄� C = =  \  C =  m � 㝐 졠 R   R = \ R = ´  =  ᆠ鼀 \   

黨㡰 ᔼ   ��盐QR�矄  ᆠ 泐 QS�矄 ᆠ 泐CQ �矄 ᨨ鼀

t㦨ᆠ 鼀

�

҈  = ҈� ´ ҈ - = N \m = ҈� ҈ ҈҈�  ᆠ盐ᨨ  N ; ҈� 

�ᆠ鼀

黨

ᔴᨨ鼀� ��犨� 맔҈黨矄犨�㦨� ⼄盐 ᆠ泐 ᨨ矄 ᨨᆠ  �犨� 鼀 �盐鼀

 ´ ҈ c = = � ´ ҈҈  l  ´ ҈ -҈ l 处 ␔ � � 鼀 �盐鼀l1 = = = 处 Ҙ ҈� f =

WWW.JEEBOOKS.IN

EBD_8341 P-270

æ ҈ ö ÷ ᨨS ç � ns =  ҈� ø è

V V  ´ ҈ f鼀 �盐鼀 = med�um = a�r = = � ´ ҈҈  l med�um l a�r  ´ ҈-䰘 c ᨨᆠ�泐ᨨ �� �  鼀 �盐鼀 V = m

NA =



v  ´ ҈ =  ´ ҈-䰘 m ␔ �  l = = f � ´ ҈҈ ᆠ 㡰 ᨨ鼀 和 Ἐ矄犨 n҈ 矄� q� = n 矄� q f  ᲼Q ҈    �  ᆠ矄

꾀�

 桌 l  矄ᨨ   ᆠ��  ᨨ  矄 矄n z㡰盐 ᨨ ᨨ nᔼ  ᆠqf  矄ᨨ n ᆠ盐矄  �矄ᆠ鼀  l㡰 �矄ᨨ矄矄� 盐 m ᨨ 矄   �ᨨ � ᆠ�  ᆠq� ᆠ 㡰 ᨨ 泐盐 �ᨨ矄ᨨ�   ᆠ�ᨨ

n \ n҈

æ n ö ᆠᨨ矄C㦨 ҈ - ç ÷ è n҈ ø



҈

n n҈

ns

� 黨   = NA㦨 ҈  

 � 黨 黨  = NA㦨   ҈  ҈

҈� � 黨 NA㦨  ҈ 

 ҈� 

ᨨ 㦨҈�m졔҈

҈�m㦨

ᨨ m㦨

Y

 NA = 

X

O 6Ö 3�

 黨  � �



��㡰

  黨 ҈� ҈�  =  NA = � � � 

҈�

>

X

 8Ö 3 O �+ 6 Ö3 -10K M

꾀㦨Ö � + Ö 10k ��b㡰

M

 ҈�  �

ᨨS � n矄=

Y

Z

M¢  Ö3 +8 � 3 6Ö 8Ö3 

ᨨS � 犨㡰

=

ᨨS � �㡰

҈� � = R ҈� m + ҈㡰 R

>

è

 ö ÷ ҈� ø

ᨨ

>

æ

҈ ҈� ҈ - ҈� = ¥ - ҈�mR + R㡰 -R

 

x㜠y �矄 ᨨ盐 泐犨 鼀 �盐鼀㜠҈ 鼀 �盐鼀㜠 

䰘

n҈  n

ᨨs҈ ç � n矄 =

ᨨ

ᨨ

ᨨS҈ � 犨㡰

NA =

R

ᨨ v҈㦨 ҈�mR㡰

 ᨨ ᆠ盐 矄盐 ᆠ

ᔴᨨ

ᨨS҈ � �㡰

=

҈� ҈ ҈� - ҈ = ¥ v҈ - mR

\

m҈ m  m҈ - m  犨 u㦨v҈졔Rv㦨¥ = v u r

n҈ n҈ NA㦨矄� �m㦨 n ᆠᨨ矄 C = n s s NA =

m 㦨҈�

P ҈�mR v҈

ᨨ犨 ᨨ鼀⼄ �㡰 盐鼀�ᆠ 盐

\

R

N

�m

꾀矄ᨨ矄� C㦨

m  m҈ m  - m҈ = v u r

�矄 ᆠ�ᨨ ᨨᆠᆠ盐矄ᨨ  矄盐 ᆠ ᨨ犨 �ᆠ r㦨¥



ᔴ 黨 ᔴ





>

n矄

m㦨҈� mR

n

ᔴ � �

꾀�

P

꾀 �ᨨ � ᆠ�  ᆠ�>ᆠ��ᆠ � q ᆠ ҈ ҈ ҈ ᨨ 矄� �° > ᨨ > ᨨ n >  ᨨ n > ҈҈ n  n ᆠ㡰 矄� �和 矄犨P錐 ns矄� �m㦨n҈矄�  黨 ᔴ㡰 �㡰 n矄㦨  ᆠ��  ᨨ 矄盐ᨨ盐 � � 턼

n҈  n

>



҈ ns

NANA҈ \ 盐鼀�ᆠ盐ᨨ ᆠᨨ鼀�  矄盐ᆠ盐�矄⼄盐ᨨ  矄鼀盐ᨨ  犨ᨨ 盐鼀�ᆠ盐矄 꾀泐 ᨨ鼀盐 ᨨ  ᆠ�ᨨ    矄 �ᆠ 矄盐 ᆠ 犨   ��  矄 ᨨ鼀� m҈㦨҈㡰ᨨ鼀 �盐鼀 m㡰



 ´ ҈ =  ´ ҈ 鼀 ⏌ 矄 錐 ҈�

盐鼀�ᆠ盐 NA =

>





 黨 黨  = � � ҈

>



�

 ҈� ҈

>

=

l med�um =

>

҈

l a�r  = = 处 m ҈� ⼄盐 ᆠ泐 ᨨ矄 ᨨᆠ  �犨�  鼀 �盐鼀

\

>



Physics



 黨  =  � � 

��盐 㡰矄 ᨨ犨矄ᆠᨨOM Ἐ㦨  � +   $

ur

��盐 㡰矄 ᨨ犨矄 ᆠᨨ A =  $� +   $ - ҈ k$

 �ᆠ盐ᨨ� MOMἘ�矄Z㜠 �矄犨 �ᆠ  矄盐 �ᆠᨨ ᨨ  k$ 

WWW.JEEBOOKS.IN

P-271

Ray Optics and Optical Instruments

uuur

uuur

ᨨ鼀盐ᨨ  ᆠ�ᨨ   矄 �ᆠ矄盐 ᆠ ᨨ AB 矄 ��鼀 ᨨ犨

꾀 �犨 ᆠᨨ MP   OP ᆠ  ᨨ盐 泐 ᨨᨨ 盐ᆠ

uuur uuur MP  OP 㦨 MP㡰 OP㡰ᆠᨨ矄�

(

Ҙ  Ҙ҈ Ҙ҈ - Ҙ - ⏌  ҈ ҈ -  ⏌  + = Þ + = u v R -¥ v  \ v㦨鼀鼀

�矄 �矄   ᨨ矄��ᨨ  ᨨ    �鼀� 盐 ᨨ ᆠ�ᨨ     �矄 矄盐 ᆠ�鼀鼀 ᨨ  �矄矄盐 ᆠ �矄�鼀�犨�  矄�盐ᨨᆠ ᨨ  ᆠ�ᨨ  矄ᆠᨨ 矄盐 ᆠ u㦨㦨҈鼀鼀 꾀��  盐矄� �  ᨨ鼀盐ᨨ  ᆠ�ᨨ   矄 �ᆠ矄盐 ᆠ ᨨ CD -

)

 $� +   $ - ҈ k$  - k$ 㡰

= ᆠᨨ矄 �  㡰 +  㡰 + -҈㡰  + -҈㡰  Þ �㦨  �ᆠᨨ�   �ᆠ�ᨨ ᨨ MOMἘ ᨨ鼀 �� 㡰   $� +   $ $ $  $ n$ =  n = � +  � � ᲼  㡰  +  㡰  桌҈⏌ 

ᨨ �   �ᨨ  ᆠ�ᨨ 犨盐矄和 Ἐ矄犨 

矄� � 矄� ° = Þ r 㦨� 矄� r 矄� r

=



 -҈ Ҙ҈ Ҙ +Ҙ - Ҙ҈ ҈  ⏌   - + =  - + = u Ἐ vἘ R ҈ v Ἐ - \ vἘ㦨�鼀鼀 � � �鼀��矄 ᨨ鼀 �鼀鼀ᨨ  ᨨ 矄ᆠᨨ 矄盐 ᆠ ��㡰 泐 ��鼀矄 ᨨ犨� � ᨨ矄��ᨨ 矄 ᨨ ᨨ   �鼀�矄

ᔼ ᆠ�  泐 A x㜠y  

� M



^r

M'

O

矄� r㡰 n^

^  ᆠᨨ矄r㡰 k C



A

 ᆠ 泐

V'

I'

ᨨ犨 r$ = 矄� r 㡰 n$ - ᆠᨨ矄 r 㡰 k$



é  ù 㦨 矄� � 㡰 ê $� + $ ú - ᆠᨨ矄 �°㡰 k$ ë� � û ҈ ᲼�$ +  $ - �k$ 桌 \ r㦨 � 

 �ᨨ � ᆠ�  ᆠ ᆠ盐 矄盐 ᆠᨨ  ᆠ泐� �ᆠᨨ �矄�� 泐 黨 b㡰

��  � � ᨨ  ᨨ矄 ᨨ鼀� ᨨ鼀 ᆠ盐 矄盐 ᆠ ᨨ  ᨨ �   � 黨  b㡰�矄�   ᆠ��ᆠ � ᔴ

I

V

A

b

鼀鼀



�鼀鼀

�㡰 x�矄 � ᆠ�   � ᨨ ᆠ�ᨨ  ᆠAC ᨨ   �矄鼀 ᨨᨨ�   ᆠ�ᨨ  x>�ᔴ ᆠ��ᆠ �㡰

A

x

y

x

黨 x

y

y

B

黨 y

M

C

N

y � ᆠ�   �ᨨ  泐ᨨ  ᆠCB ᨨ  �矄鼀 ᨨ ᨨ �    ᆠ�ᨨ

y>�C \ x졔y>�C 盐 x㦨ÐA y㦨ÐB ᨨ鼀 �ᨨ鼀泐㡰 \ x졔y㦨黨 Þ 黨>�C Þ �C� \ 㝐� �鼀盐鼀盐ᨨ  ᆠ��  nᨨ  鼀 �盐鼀 ᨨ �矄 ᨨ  ᨨ矄矄�

҈ 犨 C�矄 ᆠ��ᆠ � 矄� C C㦨黨 b ҈ ҈ Þ Ҙ 矄� 黨° - b㡰  Þ Ҙ ᆠᨨ矄b ҈ 꾀矄�鼀�� �ᆠ矄Ҙ㦨  �㡰 ᆠᨨ矄b 꾀泐� � 和 Ἐ矄 犨  A 矄� a 矄� a Ҙ㦨  Þ 矄� b㦨  ��㡰 矄� b Ҙ ᔼ a㦨p⏌矄�鼀�� �ᆠ矄ᨨ   ᨨ ᨨ 矄� a 矄� p ⏌  ҈ \ 矄� b㦨 㦨  Þ Ҙ㦨  ���㡰 m 矄� b Ҙ ᨨ鼀⼄ �㡰  ���㡰矄�  b㦨ᆠᨨ矄b ᨨ b㦨� ҈ ҈ = \ Ҙ㦨 ᨨ Ҙ㦨  ᆠᨨ矄 �° ҈⏌  \ 矄盐ᨨ   ᆠ��  ᨨ ᨨ  ᨨ��  � � � Ҙ

黨

D

␔꾀 쟼

黨 b

 ᨨ   ᨨ� �� ᨨ鼀 ᆠ盐 矄盐 ᆠ�矄   �㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ 鼀ᨨ �� �矄� � � 犨泐矄 �ᆠ盐ᨨ  �盐矄 鼀 ᔼ ��泐  ᨨᆠ �矄 �   矄 鼀 �盐鼀   u 㦨 ¥ 盐矄� �  

鼀鼀 꾀ᔼ 쟼

B

B a

鼀鼀

n㦨 ��㡰

҈ ҈ = =  矄� �C 矄� �°

ᨨ n㦨

� 

҈ ҈  = =  Þ �CἘ㦨䰘 Ҙ �⏌  � y㦨  ෌� 㡰\x㦨 x>�CἘ 盐 y�CἘ \ ᨨ�   ᆠ�ᨨ 犨�├ᆠᨨ  ᆠAC盐 ᨨᨨ

CB 矄� �CἘ㦨

Topic-3 : Refraction at Curved Surface Lenses and Power of Lens ҈

㡰 ᨨᆠ � ᨨ  ᆠᨨ   矄f㦨�鼀 졠ᆠ�矄f矄ᨨ�鼀� I҈㡰犨�矄ᨨf ᔼ鼀�ᨨ I҈�I犨�҈鼀 � 鼀�ᨨ

WWW.JEEBOOKS.IN

EBD_8341 P-272

Physics

ᨨ犨I犨�ᨨᆠ ᨨ 矄 ҈鼀

҈鼀

졠ᆠ

�

҈鼀

҈鼀

I

I҈ 㝐�ᨨ

f㦨�鼀

\ u = -҈㡰 + -҈㡰 + -҈㡰 = - 鼀 ҈ ҈ ҈ - = v u f ҈ ҈ ҈ ҈ ҈  = + = + ᨨ v = =  鼀 v f u +� - �  ᆠ �矄 ᆠᨨ �鼀� ᨨ鼀鼀�ᨨ 㦨졔㦨鼀  㡰 ෌� 盐矄� � 矄鼀├Ἐ矄 ᨨ鼀盐

矄� � 矄 ᨨ鼀盐





æ ҈ ҈ ҈ö = k - ҈㡰 ç - ÷ f è R҈ R ø R҈㦨R㦨R ᨨ ᨨ盐ᆠᨨ   矄㡰 ҈ ҈ ö æ҈ \ = m - ҈㡰 ç ÷ è f R -R ø

҈  Þ P = = m - ҈㡰  �㡰 f R ᨨ ᨨᆠᨨ   矄 R҈ = R Ἐ R = ¥ 矄� � 矄鼀├Ἐ矄 ᨨ鼀盐�� 犨  æ ҈ ҈ö ҈� P = ( m - ҈) ç - ÷  ��㡰 è RἘ ¥ø



k k ҈ ҈ = k҈ +  �� � � ᨨ  矄� 矄泐㡰 Þ  -  k҈ u v v u ҈ ҈ ҈ ᔴᨨ鼀� �犨�  矄 ᨨ鼀盐 v - u = f  犨� Þ

k҈ = 䰘

 m -҈ Þ P=  RἘ ᨨ鼀 �㡰  ��㡰 R  RἘ = Þ RἘ =  R  㡰 ᨨ鼀 矄 ᨨ鼀盐

҈ b ҈ \ f= =   f  ├㦨҈ c 矄ᨨᨨ m - v �

҈  = f҈ fl f҈㦨҈ᆠ鼀ᨨf҈㦨黨ᆠ鼀 ҈  和ᨨ 黨 = f ᨨfl㦨҈ᆠ鼀 l 㡰

҈ ҈ æö æö = m - ҈㡰 ç ÷ ᨨ = ҈� - ҈㡰 ç ÷ fl ҈ èRø èRø \R㦨҈ᆠ鼀 犨  �⼄盐� �矄盐 犨  

҈   ҈   = + ᨨ 䰘 ⏌ 㡰 = ҈ + f f fl f ᨨf㦨�ᆠ鼀 ҈ ҈ æ ҈ ö = m҈ - ҈㡰 ´ = m҈ - ҈㡰 ´ ç ᨨ犨 ÷ � R è -҈ ø ҈  \m҈ = + ҈ =    ´  ᨨ盐 矄㡰 v҈ = (    ) =  cm 矄� �

uf ҈ ҈ ҈ - = Þv= v u f u+ f



㡰 ᨨᆠ �  ᨨ   ᨨ㜠ᆠᨨ    矄㜠 ҈ ҈ ö m҈  ҈ æ҈ Þ ҈ = = ( m҈  ҈) ç  ÷= ( m҈ ҈) ҈ è ¥  ø ᨨᆠ �  ᨨ  ᨨ㜠ᆠᨨ ᆠ 矄㜠  ҈ ҈ ö m ҈ æ ҈ Þ  =  ÷=  = ( m  ҈) ç ( m  ҈)   è  ¥ ø ᨨ   ᆠᨨ鼀� �ᨨ ᨨ 犨ᨨ  矄㜠 ҈ ҈ ҈ m ҈ m   ҈ m  m ҈  Þ =  = + = ҈ ⼄  ⼄ ҈  = m ҈  m 㡰 ᨨ鼀 ⼄盐�ᨨ ᨨ �  鼀㦨├҈졔├ Qy㦨mx졔c㡰 v vö æ Þ = k҈v + k çQ m = ÷ u uø è

ᔴ矄㜠ᔼᔼ v㦨u Þ f + u = f Þ u =  ᔴ矄㜠ᔼᔼᔼ  u = ¥   v = f  ᆠ ᆠᨨᆠ u 矄盐矄 v �    矄�矄 �矄  �矄 ᆠᨨ ��ᨨ  �矄 㡰 b㡰 矄� � 矄鼀├矄 ᨨ鼀盐



盐㦨㦨ᆠ鼀

öé ҈ ҈ æ mg ҈ ù =ç ҈ ÷÷ ê  ú f çè ma R R û øë ҈  mg    ma     ᆠ� �   ᨨ  �矄矄   � 矄ᆠ�泐

æ ҈ ҈ ҈ ö Þ = ҈�  ҈㡰 ç  ÷ f è R҈ R ø ␔  �鼀鼀矄 � �⼄盐�

 �㡰

\v =

黨

 ´҈ =  cm  ( ҈ )

\ᔼ鼀�ᆠ矄ᆠ├ᨨᨨᆠ�矄 矄�鼀� ᨨ鼀 泐 矄�矄 ᆠ ᨨ ᆠ盐盐ᨨ 鼀�ᨨ ᆠ㡰 ᨨ  矄

öæ ҈ ҈ æ mg ҈ ö = çç ҈ ÷÷ ç  ÷ fl è ml R R è ҈ ø ø ᲼ml㦨 ᆠ��  ᨨ �⼄盐� 桌

҈ æ ҈� öæ ҈ ҈ ÷ ç  =ç fl è ҈ ø è R҈ �� � � �㡰 泐 ��㡰 fl ҈�  ҈㡰҈ Þ = = f  Þ

҈ ö ÷ R ø

 ��㡰

҈ ҈ = »黨 ҈ ҈

҈ ҈ ҈ - = ᨨ v u f \ v㦨졔ᆠ鼀

҈ ҈ ҈ = v - 

WWW.JEEBOOKS.IN

P-273

Ray Optics and Optical Instruments

҈

҈҈

҈

꾀ᆠᆠᨨ � �ᨨ ᆠᨨ ��ᨨ �鼀� ᨨ鼀 泐 矄矄 ᨨ盐   ᆠ ᨨ ᆠ盐盐ᨨ  鼀�ᨨ  矄ᨨ f㦨ᨨf㦨҈ᆠ鼀 ҈ ҈ ҈ 㡰 泐 矄矄 ᨨ鼀盐 - =  盐 ᨨ �矄 矄᲼盐҈㦨桌 ҈ ҈ ҈  = Þ ᔼ = ҈ - �  ᔼ鼀� ᨨ鼀 泐 �矄 矄犨� 矄  ᨨᆠ ᨨ矄ᆠᨨ  矄  ҈ -= 矄ᨨ 盐  =   ҈ ҈ ҈ = Þ  = 䰘 ᆠ鼀  ҈ -�  㡰 꾀ᆠᆠᨨ � �ᨨ 矄鼀├Ἐ矄 ᨨ鼀盐

҈�

矄� � 矄 ᨨ鼀盐 ҈ ҈ ҈ ҈ ҈ ҈ - = Þ = Þ = �ᆠ鼀  盐 ҈ -҈ æ ҈ö 和 �  盐ᨨ矄 =  ç҈ - ÷ �   �ᆠ�ᨨ ᨨ � ᆠ�  泐 è mø

æ ö ᨨ = ҈� ç ҈ - ÷ = � è ø ᨨ犨盐㦨黨�

æ ҈ ҈ ö ҈ 㦨 m  ҈㡰 ç  ÷ è ҈ ø

꾀�� 盐矄� � 矄 ᨨ鼀盐矄

ᨨᆠ � ᨨ  矄犨�ᆠ  � 盐ᨨᆠ  ��  ᆠ��  m 和ᨨ �鼀� 犨�  ᨨ鼀   犨 ᨨ矄��ᨨ   ᆠ �鼀� �矄矄 㡰 泐  矄 ᨨ鼀盐 ҈ ҈ ҈ ҈ ҈ ҈ = - = 錐  -㡰   盐

Þ

҈ ҈黨䰘  ҈ ҈ ҈ = 錐 = = 錐      ҈黨䰘 㝐� � �ᆠ�ᨨ ᨨ  矄 鼀㡰�矄��  泐

҈

҈ f 鼀�ᨨ㦨¥㡰 f



�� � �

҈ ҈ ҈ ҈  = [Q盐 = ¥]  ¥ 䰘 \㦨䰘鼀鼀㦨䰘ᆠ鼀;҈ᆠ鼀

҈ æ m  ҈ö = ç ÷  è R ø

ᔴ矄㜠

҈ ҈ö æ ҈ = (Ҙ - ҈) ç - ÷  è - ¥ ø

Þ

㦨

 Qᨨ犨P㦨

æ ҈ ҈ ҈ ö ҈ ҈ ö ҈ æ҈ = (Ҙ҈ - ҈) ç = (Ҙ - ҈) ç ÷ 錐 ÷= ¥  è ø è ҈ ø ҈  和�鼀�泐 ᨨ ᨨ㜠ᆠᨨ ᆠ  矄

m҈㦨1 m㦨҈



㦨҈졔 Þ



҈

b㡰 ᔴ矄㜠҈

҈ æ m ҈ö =ç ÷ f҈ è R ø

æ  ´ ҈ ö ᔼ⏌ = ç �㡰 è ҈黨䰘 ´  ÷ø 㦨҈҈맔҈鼀⏌矄ᨨ犨 矄  矄 b㡰 ᨨ鼀 矄鼀├矄 ᨨ鼀盐

҈ ҈ 泐 犨� ҈  (Ҙ҈ - ҈) ( Ҙ - ҈) = ᨨm҈Ҙ㦨҈  m m҈ m  m҈  㦨䰘鼀鼀 㡰 盐矄� �  =  盐

҈ ҈ ҈ =  -黨� �

҈ ҈  黨 = - =  � ҈黨 黨� 黨� = ҈��ᆠ鼀 ᨨ  = 黨

盐矄 矄ᆠ  �矄矄 �  泐 �矄 ᆠ 㦨҈��҈㦨��ᆠ鼀犨泐 ᨨ鼀  矄

æ  ö ç ÷ æ  ö è ҈黨䰘 ø 鼀= ç ÷ = è 盐ø  ᨨᆠ�泐ᨨ �鼀�犨ᨨ 矄�矄��  泐 ᔼ⏌㦨鼀졠⏌ �ᆠ�ᨨ ᨨ ᨨᆠ�泐ᨨ �鼀��矄矄鼀矄 ᨨ ᨨᆠ 졠⏌㦨�鼀⏌矄

҈



҈䰘

R ҈ æ m ҈ ö f㦨҈ᆠ鼀 f =  =ç ÷  f҈ è R ø ҈ æ m ҈ö  = ç 㦨҈졔2Þ ÷+ ҈ è  ø R ҈ ҈  = + Þ  = ҈ -  = ҈ ᨨ ҈  R R ҈    ᨨ = ᆠ鼀 黨 ҈ � æ m ҈ ö = ç ᨨ ÷ 黨 Þ m҈㦨  è  ø 黨 � ҈ \ m㦨 ҈ + = 㦨҈�� 黨 黨 㡰 ෌�  ᨨᆠ � ᨨ  矄 㡰㦨҈�ᆠ鼀 ᨨᆠ�矄ᆠ  �矄 ᆠ 盐㡰㦨ᆠ鼀 泐 矄 ᨨ鼀盐 ҈ ҈ ҈ = -   盐 ҈ ҈ ҈ ҈ ҈ = + =  盐 ҈�  ҈  - = ᨨ㦨ᆠ鼀  

㦨҈�ᆠ鼀

㦨�ᆠ鼀

WWW.JEEBOOKS.IN

EBD_8341 P-274

҈

Physics

�鼀�ᔼ�矄 ᨨ鼀 ᆠ鼀ᨨ �� ᨨ   矄 � 犨�  �  

泐矄 ᨨ鼀 �鼀� ᔼ㡰 ᨨ鼀  盐  矄ᨨ  ᆠᨨ  鼀�ᨨ ᨨ鼀矄 ᨨ �鼀� �矄�鼀�矄 ᨨ盐  ᨨ鼀 � 矄盐ᆠ  犨泐 �ᆠᨨ� ᆠ� 犨� ᨨᆠ 矄鼀ᨨ�  盐ᨨ ᆠ�ᨨ

├矄ᆠ 泐ᆠᨨ  鼀�ᨨ �矄 ᆠ犨  矄 鼀�ᨨ犨� 㦨�鼀� �矄 ᆠ 㡰 �盐矄ᨨ ᆠ盐盐ᨨ ᆠᨨ  鼀�ᨨ �㦨 ᨨ  㦨� �� = = 䰘� ᆠ鼀 ᆠᨨ  鼀�ᨨ㡰  b㡰 ෌�  �盐矄ᨨ  鼀�矄 �ᆠ�矄矄 㦨҈ᆠ鼀

҈ 㦨�ᆠ鼀  盐㦨 ҈㡰㦨ᆠ鼀 泐盐矄� �鼀�ᨨ ᨨ鼀盐 ҈ ҈ ҈ ҈ ҈ ҈ + = Þ + = Þ㦨ᆠ鼀  盐  - -� m ҈ =  ᆠ鼀  ᨨ犨  꾀  ��  ha = hr ҈ =  ´ ҈� m 矄盐 ᆠ ҈ ҈ ҈ = 㡰  Ἐ矄 ᨨ鼀盐�矄��  泐  盐 \ ᨨᆠ �  㦨

҈黨



æ ҈ 1 ö ҈ = ( 鼀 m l - ҈) ç ÷ 鼀 è ҈  ø ᔼ  �矄  ᨨᆠ � ᨨ  矄� � 

æ ҈ 1 ö ҈ 鼀 (  ml - ҈) = (  ml - ҈) ç ÷ Þ =  è ҈ ø  ( 鼀 ml - ҈) ᔼ m҈> m   鼀    ᨨᨨ矄� 矄�� 矄    盐 ᨨ  矄ᆠ  �矄�ᆠᨨ   矄 ��矄 �� 泐矄 ᆠᨨ ᆠ  矄ᆠᨨ �矄 �� 泐矄 盐矄�� ᨨ�ᨨ  㡰�矄ᆠᨨᆠ





҈ ҈ ҈ ҈ ҈ = Þ = -҈     �盐ᨨᆠ҈ᆠ鼀 �  鼀�ᨨ  ᆠ�鼀�҈ᆠ鼀� ᨨ ᨨ 鼀�ᨨᨨᆠ鼀 ᨨ鼀ᆠᨨ   矄 㡰 ␔   ᨨᆠ �矄 ├   �矄 ᆠ �a ᨨ鼀  �  ᆠᨨ   矄

泐  矄 ᨨ鼀盐 

҈ ҈ ҈  = v u f

҈ ҈ ҈ =  V  a 㡰 f

\ =

ᨨᆠ�泐 ᨨ ��  � ᆠ盐盐鼀 ᨨᆠ�泐 ᨨ ��  � 鼀 �盐鼀

 

졔 鼀鼀㡰㦨  Þ 졔  鼀鼀㡰졔 鼀鼀㡰㦨  Þ »҈�ᆠ鼀 ҈ æ  öæ ҈ ö = ç ҈ ÷ ç ÷ Þ 㦨ᆠ鼀 è  ø è ҈� ø 㡰 ᔼ 矄� ᨨ ᨨᆠ矄⼄盐㦨l  矄� ᨨ �鼀�矄⼄盐㦨l¢

㦨ᆠ鼀 鼀鼀

l Ἐ lἘ =黨 = ᨨ l l �鼀� � �ᆠ�ᨨ 鼀㦨 盐㦨ᆠ鼀 㦨맔㦨҈ᆠ鼀 㦨䁸 ҈ ҈ ҈ ᨨ鼀 ᨨ鼀盐 - =  盐 ҈ ҈ ҈ ҈ ҈ ҈ ҈+  = + = ᨨ = ҈ - ҈  ҈ \ 㦨ᆠ鼀 l� ҈  = = = ҈� ᆠ㡰  Ҙ = l鼀 �盐鼀    ᨨ鼀⼄盐矄�ᨨ 

和�鼀�泐 ᨨᆠᨨ ᆠ 矄



ᆠ㡰

\ =

҈ ҈ ҈ ҈ ҈ = + Þ =     

ᨨᆠᨨ   矄

㡰 ᔼ  矄ᨨ  ᆠ��  m�矄�鼀鼀矄 � 鼀 �盐鼀ᨨ  ᆠ��  m҈  �矄 ᨨᆠ � � 鼀 �盐鼀�矄�� 泐

O I҈ v

�

҈ ҈ ҈ a =   �㡰 v f a 㝐�ᨨ ᨨ鼀矄 �鼀�  ⼄盐 �矄 ᆠ ᨨ鼀 鼀�ᨨ

꾀矄ᨨ 鼀 =

ᨨ

 ҈ = - Qv㦨m㡰 盐 

\ 盐 = - ᆠ鼀

ᨨ ᨨ㜠ᆠᨨ   矄 I҈

v

v

҈ Ҙ - ҈㡰 ҈ ҈ ҈� - ҈ ҈ æ ҈ ö ҈ ҈ ҈ = = - ᨨ = -ç = ÷= +  è - ø     盐

I

\ 㦨鼀

ᨨ犨 ��  ᨨ鼀  矄 ᨨ鼀盐  I

I

⏌ v

҈

ᆠ㡰 Þ \

Fᨨr cᨨnvex lens

҈ ҈ ҈ =  -�  㦨䰘�ᆠ鼀

ᨨ m L҈ =

  f҈ =  R 

� ᨨ m L  =  f  = -� R Þ f㦨 㡰 

Qv㦨�ᆠ鼀f㦨ᆠ鼀㡰

� ᆠ� �矄ᨨ 鼀�ᨨ ᔼ¢

 ҈ ҈  ҈ ҈ ҈  =  + =    ᨨ ᲼ ᨨ鼀 ⼄  �㡰桌 a V f a f a f  ᆠ a 㦨 f b㡰 泐 矄鼀├Ἐ矄 ᨨ鼀盐 ᨨᆠᨨ   矄 öæ  ö ҈ æ m =ç - ҈÷ ç ÷ f è mL øè R ø

҈ ҈ ҈ - =  盐

� 

�ᆠ鼀  ᔼ

 � 꾀 � ᆠ�  �矄ᨨ   矄



㝐�ᨨ

�鼀� ᨨ鼀 泐ᆠᨨ   矄ᆠ矄矄 ᨨᆠ ᨨ鼀�ᨨ

WWW.JEEBOOKS.IN

P-275

Ray Optics and Optical Instruments ҈ ҈ ҈ ҈ ҈ ҈ + = \ + = \㦨�ᆠ鼀  盐  � �

�鼀�ᔼ犨ᨨ盐   ᨨ鼀 矄矄 ᨨ犨    鼀�ᨨ

矄�� 盐  鼀�ᨨ�矄� 泐   ᨨ �鼀� 犨�� 泐  犨� ᨨ鼀 꾀 㝐꾀㦨�ᆠᨨ矄 㦨�ᆠ鼀 x㜠ᆠᨨᨨ � ᨨ  �鼀�㡰  ᔼ¢꾀㦨�矄�  㦨 �  ᆠ鼀 y㜠ᆠᨨᨨ � ᨨ  �鼀�㡰  ᆠ ᆠᨨᨨ �  ᨨ    ᨨ�   犨 �ᆠ  �鼀� �矄 ᨨ鼀  � �  㡰 b㡰  ᨨᆠ  �  f ҈㡰 ᨨ     ᨨ㜠ᆠᨨ    矄 犨� n㦨҈�盐矄� � 矄㜠鼀├ ᨨ鼀盐

䰘

҈ ҈ ҈ ҈ ҈ ҈ � - = + = Þ = \ v㦨ᆠ鼀 v ҈ ҈� v ҈� ҈ ҈�

 ᨨ � �鼀��矄 ᨨ鼀  �矄 ᆠᨨ ҈ᆠ鼀 ᨨ鼀   鼀�ᨨ ᆠ㡰 ᨨ鼀 � u㦨҈ᆠ鼀錐v㦨҈ᆠ鼀Du㦨Dv㦨҈ ҈ ҈ ҈ ҈ ҈ ᨨ鼀 矄 ᨨ鼀盐 = - 㦨 ҈ -҈ f v u \ f 㦨�ᆠ鼀 Þ

Fᨨr m�nᨨr



҈ vᆠ鼀 

é҈ ҈ ҈ ù é҈ ҈ù ҈ = n҈ - ҈㡰 ê ú  = ҈� - ҈㡰 ê - ú = f҈ R R ë҈ ¥ û  û ë ҈

 ᨨᆠ �  f㡰ᨨ   ᨨ㜠ᆠᨨ   矄犨� n㦨҈

҈

é҈ ҈ ҈ ù ҈ ù ҈ é҈ = n - ҈㡰 ê ú  = ҈ - ҈㡰 ê ú= f ë ¥ -҈ û 䰘 ë R҈ R û ᨨᆠ �  ᨨ  ᆠᨨ鼀� �ᨨ

҈ ҈ ҈ ҈ = + = F f҈ f   ᨨ犨泐� �  矄 ᨨ鼀盐 ᨨ  ᆠᨨ鼀� �ᨨ  ᨨ  矄



\ b㡰

ᨨ鼀  ��盐� DABC  b =

Þ

҈ ҈ ҈ = V - 

Þ AB㦨AC b Þ r㦨f  b \ r㦨 \

᲼෌� Ҙ㦨ᆠ鼀桌

AB AC

f  b 

꾀ᨨ �鼀� ᨨ鼀 泐矄盐 㦨pr 㦨 p

  b  f µ f 

和盐

  泐矄 ᨨ鼀 ᨨᆠᆠ � � �泐

ᨨᆠ  

ᔼ鼀� ᨨ鼀 ᨨ  ᨨᆠ 



b

a

r

C

B

黨

I

҈ ҈ ҈ Þ v㦨҈ᆠ鼀 = v - -҈� ⏌  ��矄�� � �ᆠ矄  �鼀��矄҈ᆠ鼀�  ᨨ ᨨ ᨨ 鼀�ᨨ  㡰 ᨨᆠ � ᨨ ᆠᨨ ᆠ 矄f㦨 - f҈  f ҈㦨 ᨨᆠ � ᨨ ᆠᨨ   矄 ҈ ҈ ҈ ҈ ҈  Þ = =  f҈  f҈ f f҈ f 



f҈㦨҈ᆠ鼀 f㦨 -

 ´ ҈ 㦨҈�ᆠ鼀 

b㡰 �鼀� ᨨ鼀 泐ᆠᨨ   矄I҈ᆠ矄矄�盐ᨨᆠ ᨨ ᆠᨨ ᆠ 矄ᔴᨨ ᆠ 矄 ᨨ鼀矄 �鼀�ᨨ I҈I 和� ᨨ  �鼀� I҈㦨ᆠ鼀 I҈

I



ᆠ鼀 ᆠ鼀

ᨨ鼀 �鼀盐鼀ᨨ�  㡰

M

L

O

 黨졔黨㡰

҈ ҈ Df = + Þ Df㦨�맔҈맔맔҈㦨� � ҈㡰 ҈㡰  \ ᨨᆠ �  f᠀Df㦨 �᠀�㡰ᆠ鼀 b㡰  ᨨᆠ  �  f ᨨ    ⼄盐�  鼀�ᨨ 犨    矄 �矄 矄�  ҈  ҈  ҈ ҈� = + = +  Þ = ᆠ鼀 f f҈ f m ҈� ¥  和� ᆠ  矄  ᨨ矄�� 盐   ᆠᨨ鼀� �ᨨ   矄 矄  ᆠᨨ �� �鼀�ᨨ ҈� u㦨ᆠ鼀 f = - ᆠ鼀 v㦨䁸  ҈ ҈ ҈ 꾀ᆠᆠᨨ � �ᨨ鼀�ᨨ ᨨ鼀盐 + = v u f

\

�ᆠᨨ   矄

b㡰 ᨨᆠ � ᨨ  �ᆠᨨ   矄L�矄҈�ᆠ鼀꾀矄鼀ᨨᆠ �矄ᆠ  �矄 ᆠᨨ ᆠ鼀 ᨨ鼀  矄� �矄 ᆠᨨ    ᨨ �鼀�矄 ᨨ盐  ᨨ鼀ᆠ鼀 ᨨ鼀  矄I҈

҈

Þ

f

A



Þ

҈

҈ ҈ ҈ - = V U F V㦨ᆠ鼀



uᆠ鼀҈

�  �� �  矄 ᨨ鼀盐 ҈ ҈ ҈ Df Dv Du = - Þ = + f v u f  v u

҈ᆠ鼀

ᆠ鼀

ᆠ鼀

ᆠ鼀

�鼀� I҈ᆠ矄 矄�盐ᨨᆠ ᨨ  鼀�ᨨ 鼀�ᨨ ᨨ鼀矄 �鼀�I �矄 ᆠᨨ ᆠ鼀�  ᨨ ᨨ �

�鼀�Iᆠ矄矄 ᨨᆠ ᨨ  矄 u㦨졔҈ᆠ鼀f㦨졔҈�ᆠ鼀 ҈ ҈ ҈ 꾀泐� �  矄 ᨨ鼀盐 - = v u f

I

ᨨᆠᨨ ᆠ 矄 ᨨ ᨨ

҈ ҈ ҈ - = v u f

҈ ҈ ҈ ҈ ҈ ҈  ҈ - == ᨨ = - + =     � v  v v㦨�ᆠ鼀㦨�矄 ᆠᨨ I ᨨ鼀ᆠᨨ ᆠ 矄

WWW.JEEBOOKS.IN

EBD_8341 P-276

\

Physics 㝐� � �ᆠ�ᨨ m㦨

v 矄�  ᨨ �鼀� � = = u 矄�  ᨨ ᨨᆠ 

\

矄�  ᨨ �鼀� = ҈�  \ 和� ᨨ �鼀� 盐ᨨᆠᨨ ᆠ 矄㦨�ᆠ鼀 㡰  矄鼀├ ᨨ鼀盐 ᨨ



�

҈ ҈� + ҈ � ҈ = = = ҈� ҈�  v v㦨ᆠ鼀

\

꾀 鼀� � �ᆠ�ᨨ m҈㦨 -

҈ æ Ҙ ö æ ҈ ҈ ö = -҈ f èç Ҙ҈ ø÷ èç R҈ R ø÷ m ҈ m  m ᔼ  m > m҈   ᆠᨨ ᆠ 矄 鼀� � 矄 �矄

盐 ᨨ 犨�矄   盐 ᨨ     矄 犨�  矄  和ᨨ  矄矄 ᨨ盐  � 犨�  L �鼀鼀矄� L҈ 㡰 ᨨᆠᨨ ᆠ 矄矄矄 ᨨ犨 �  ��盐�  �矄ᆠ矄 R҈㦨R R㦨졔R

鼀 㦨҈ᆠ鼀

l 㦨졔҈ᆠ鼀

҈�ᆠ鼀

ᆠ鼀 �ᆠ鼀

gm

mm

- v =㦨 -҈� u

ᨨ犨 ᨨ ᆠ�ᨨ  ᨨ鼀 矄u㦨 �㡰㦨ᆠ鼀

҈ ҈ ҈ ҈ ҈ ҈ - = Þ = v u f҈ v - ҈

R2

R1

㝐쟼ᔼ㝐 mm

҈ ᨨ鼀 矄鼀├ ᨨ鼀盐 = f gҘ m gҘ= mҘ

=

(

)

m g Ҙ -҈

҈ ҈ ҈ ҈ = = \ v㦨ᆠ鼀 v ҈  

æ ҈ ҈ ö çè R - R ÷ø ҈ 

 v = 㦨҈ u - 㝐� � �ᆠ�ᨨ  ᨨ 盐ᆠ  泐  ᆠᨨ鼀� �ᨨ  M҈㦨m҈맔m㦨 㡰맔 ҈㡰㦨 꾀�� 犨  矄泐矄鼀�矄├� 鼀 �盐鼀ᨨ  ᆠ��  䰘⏌

�矄 ᨨᆠ  � ᨨ鼀�ᨨ�  �矄ᆠ矄 㝐� � �ᆠ�ᨨ m㦨

҈� ҈䰘�

҈ æ ҈� � ´  ö æ ҈ ҈ö =ç - ҈÷ ç - - ÷ = + f è ҈䰘� ø è R R ø ҈䰘� R ᨨ f 㦨졔�R  ᆠ  矄  矄 矄 ᆠᨨ �   矄 ᨨ  ᨨᆠ  � f 㦨� ᆠ㡰 꾀ᆠᨨ  鼀�ᨨ ᆠᨨ ᆠ 矄犨泐矄ᨨ 盐ᆠ�盐 �鼀�␔ �ᆠ ᆠ

ᨨ├ ᨨ  矄ᆠ 

 ᨨᨨ�ᨨ  㡰  㡰 ᨨᆠᨨᆠ �鼀� ᨨ鼀 泐ᆠᨨ   矄�矄 �鼀� �矄  犨   ᨨᆠ�矄ᆠ 泐ᨨ f u㦨f 졔x \



ᨨ 矄

҈ æ ҈ ҈ö ҈ ö æ /  ö æ ҈ =ç - ҈÷ ç - ÷ Þ ¢ = ç - ÷ 䰘 è R҈ R ø fl fl è 䰘 /  ø è R҈ R ø 꾀矄ᨨ 犨   矄犨矄�  � ҈ ö ҈ ö ҈ æ ҈ æ ҈ ҈ ҈ fl 㦨 ҈�҈㡰 çè R҈ R ÷ø 㦨 ҈ \ çè R҈ R ÷ø 㦨 � 矄� � �矄矄盐� ⼄  �㡰犨�

䰘



҈ fl¢

=

�  ҈ ´ \ f ¢l㦨 ᆠ鼀  䰘 �

҈ ҈ ҈ 꾀�� 盐矄� � 矄 ᨨ鼀盐 - = v u fl¢ ҈ ҈  ҈  ҈ ҈ = Þ = = \v㦨҈ᆠ鼀 v - � v �  ҈

 f + x㡰  £҈ f +x

\ f졔x㡰 £ f졔x �矄�矄盐 ᨨf�鼀 ᆠ㡰 和 �ᆠ�ᨨ ᨨᆠᆠ盐矄 盐ᨨ  � ��泐ᨨ  矄ᨨ ᆠᨨ �鼀�� 泐矄ᨨ  矄鼀犨 � ᨨ  ᨨᆠ盐矄矄� ᆠᨨ �矄   �泐矄�  鼀��   �矄泐矄  ᨨᆠ盐矄矄  �  ᆠ矄ᨨ   �矄ᨨ   矄   ᨨ  �鼀�矄ᨨ ᨨ鼀 �矄盐  �矄�ᨨ ᆠ  盐ᆠ 泐 盐矄� �ᆠ�ᆠ盐

盐鼀矄├ᨨ  矄 䰘㡰 꾀泐� � 鼀�ᨨ ᨨ鼀盐 ҈ ҈ ҈ ҈ ҈ ҈ ҈ ҈ + = ᨨ =  = + v u f v f u ҈ ҈�

҈ö æm öæ ҈ = ç l - ҈÷ ç - ÷ è m s ø è R҈ R ø

¢

f  f + x 㡰 £҈ f +x

é f ù  f + x ê҈ + £҈ Þ f x úû + ë

fl¢

҈

҈ ҈ ҈ ҈ ҈ ҈ 矄� � - =  Þ  = v u f v -  f + x 㡰 f ҈ ҈ ҈ f +x- f f + x㡰 = + = = Þ v f f + x f  f + x 㡰 f  f + x 㡰 盐u졔v㦨҈ �� 㡰  f + x㡰 +

҈

v ҈ = 㦨䰘 u - 㝐� � �ᆠ�ᨨ  ᨨ 盐ᆠ  泐  ᆠᨨ鼀� �ᨨ  M㦨m҈맔m¢㦨 㡰맔 䰘㡰㦨҈

㝐� � �ᆠ�ᨨ m¢㦨

\ 黨

҈ Ἐ M 㦨 㦨䰘 M҈ 

㡰 꾀泐� � 和 矄 犨  A 矄�  㦨n矄� r �  �� �犨�n犨� 㦨矄� r졔nᆠᨨ矄 r맔

dr dn

 �㡰

 ��㡰

WWW.JEEBOOKS.IN

P-277

Ray Optics and Optical Instruments 盐矄� �

 



 r

r  r

æ ҈ ҈ ҈ ö = m - ҈㡰 ç ÷ f R R è ҈ ø

᲼ 矄㜠鼀├Ἐ矄 ᨨ鼀盐桌

æ ҈ ҈ ҈ ö = ҈� - ҈㡰 ç ÷ ҈� R R è ҈  ø

q



 �㡰

æ ҈ ҈ ҈ ö = ҈҈� - ҈㡰 ç  ��㡰 ÷ fἘ è R҈ R ø �� � �⼄ �㡰泐 ��㡰 fἘ ҈� - ҈ � = = = ҈� ҈҈� - ҈ ҈� \ f Ἐ㦨ᆠ鼀 ᨨ鼀   ��鼀 � �矄 ᆠ     ᨨᆠ盐矄 ᨨ  ᨨ     矄矄 矄 ᨨ盐 ᆠᨨ� ᆠ�   \d = 20  5㦨҈�ᆠ鼀 

꾀��  泐� �和 矄犨  B 矄� q㦨n矄�   r㡰 �  �� �犨�n犨�

q é  ù 㦨矄�   r㡰졔nᆠᨨ矄  r㡰 ê  ú ë û

ᆠᨨ矄q \

 ���㡰

é  r ù q ᆠᨨ矄q 㦨矄�   r㡰 nᆠᨨ矄  r㡰 ê  n úû

ë ᲼ ᨨ鼀 ��㡰桌 q ҈ = ᲼矄�   r㡰졔ᆠᨨ矄  r㡰 r桌 ᆠᨨ矄 q

\

ᨨ鼀⼄ �㡰 ᨨ n =

 犨�r㦨

ᨨ鼀⼄ ���㡰 ᨨ n =

 r㦨 犨�q㦨



 �㡰

 鼀



和盐矄�盐� � 盐矄ᨨ r q� ⼄ �㡰犨�



q ҈ æ ҈ ҈ö = + ᆠᨨ矄 ° ᲼矄�  졔ᆠᨨ矄   桌㦨 çè   ÷ø 㦨 䰘҈黨㡰 ෌�  �矄 ᆠ犨  ᨨᆠ 矄ᆠ D㦨҈ᆠ鼀 �矄 ᆠ犨   犨ᨨᨨ矄��ᨨ ᨨ  矄d㦨ᆠ鼀 ᨨᆠ �  ᨨ  矄 f =

ᆠ鼀

�

T盐錐



҈ ҈ ҈ - + ҈ ҈ ҈ ҈ + = Þ  = = + ҈�   F F f҈ f  \F㦨ᆠ鼀  ᆠᆠᨨ鼀� �ᨨ ᨨ  矄矄 矄矄ᆠᨨ ᆠ 矄ᨨ  ᨨᆠ  � ᆠ鼀 和� ᆠFvFr�ᨨᆠᨨᨨ盐�矄 � 鼀ᨨ   ᆠᨨᨨ盐犨 

犨 ���  矄矄矄 ᨨ盐�   矄 ᨨ�矄鼀 \ 졠  矄矄 ᆠᨨᨨ盐    犨�  �ᨨ ᆠᨨᨨ盐    ᨨ盐  � 矄錐

D  - d  ҈ -   ҈ + 㡰 ҈ - 㡰 = = = ҈ ᆠ鼀 D  ҈㡰  ҈㡰

ᨨ犨 P =

N ҈ ҈ = = ҈ ҈ f

\ N = 䰘҈黨 ҈

㡰 ෌� m㦨҈�錐Rᆠ盐 㦨ᆠ鼀 矄� � 矄㜠鼀├ ᨨ鼀盐

�ᆠ鼀



�鼀� ᨨ鼀 泐 ᆠᨨ   矄  ᨨᆠ盐矄ᨨ  ᆠᨨ ᆠ  矄  ᨨᔼ犨�ᆠ矄�盐ᨨᆠ ᨨᆠᨨ ᆠ 矄 �鼀�犨� ᨨ鼀 � � �泐 ᆠ  ᆠ�ᨨ  ᨨ鼀ᨨ   矄矄泐矄犨�ᆠᨨ鼀ᨨ ᨨ�ᆠ �矄

æ ҈ ҈ ҈ ö = m ҈㡰 ç  ÷ f R R è ҈  ø ᨨ  ᨨ㜠ᆠᨨ    矄

R҈ ® ¥   R =  R R  = =  ᆠ鼀 m ҈ ҈�  ҈ ␔  犨ᨨ 矄矄� ᆠᨨ ᆠP㦨P҈졔P㦨҈ ␔  犨ᨨ 矄矄矄 泐 �矄 ᆠ 㦨�鼀㡰P㦨P҈ 졔P �㡰P҈P㦨 ᨨ鼀  矄 犨ᨨ  矄矄�ᨨ 矄 犨 � P҈P㦨҈鼀 \f =





P҈ - P = P҈ + P 㡰 -  P҈P



\

 = ҈-҈ 㡰  -  ҈-҈ 㡰 = 鼀 -҈ P҈㦨鼀҈ P㦨鼀҈

\

f҈ =

m gm

=

gm mm

҈ ҈  ҈ = 鼀 = ҈�鼀  f  = = 鼀 = �鼀 P҈  P 

=

҈� = ҈҈� 

ᔼ �盐 ᨨᆠ ᨨᆠᨨ ᆠ  矄

䰘�鼀

䰘

 㡰 ᨨ鼀 ��盐� D졠꾀 㦨  㡰졔 㦨  졔 졔 Þ  㦨 졔

\ =

 +  

 ᆠᨨ�ᨨ  㡰�矄ᆠᨨᆠ ᨨ犨 ᨨ鼀⼄盐�ᨨ ᨨ 矄盐 ᆠ

�鼀

졠 

– 



WWW.JEEBOOKS.IN

EBD_8341 P-278

Physics

泐 = 泐 + =

u㦨xv㦨졔xR㦨졔RҘ҈㦨҈Ҙ㦨҈�

w   �

-҈ ҈� ҈� - ҈ + = \ x㦨�R 㦨PO -x x R

w   �

�

ᨨ犨盐矄� � ᨨ鼀盐 ᨨ ᆠ�ᨨ ᆠ盐 矄盐 ᆠ �҈

m m҈ m  - m҈ - =  盐   ҈҈   =  -  - 㡰

Þ

҈ ҈    

�

b㡰 和 �ᆠ�ᨨ  �矄 矄鼀 犨     ᆠ盐  矄盐 ᆠ �矄 ᆠ� �   ᨨᆠ ᆠ盐矄   ᨨ ��ᨨ  �矄 矄   犨

 ᆠ盐    矄盐 ᆠ矄 bᆠ㡰ᔼ鼀� ᨨ鼀 泐ᆠᨨ ᆠ 矄 ᆠᨨ  鼀�ᨨ�矄�盐  ᆠᔴᨨ ᆠ 矄 ᆠᨨ  鼀�ᨨ ��� ��  盐

 ᨨ    ᆠ ⏌ ᆠ  泐矄 ᨨ ᨨ 鼀

矄泐矄ᨨ 盐ᆠ ᆠ├犨 矄ᨨ鼀├ 鼀鼀 b 㡰 �鼀� ᨨ鼀 犨�ᆠᨨ鼀ᆠ盐矄�� 泐矄 ᨨ鼀 矄ᨨ   ᨨᆠ 犨�矄�├ᨨ   ᨨ犨  

᲼Q 桌

A

҈   =     ҈  é w  ù Þ =ê҈ ú   ëê � ûú

Þ

 é w  ù \ = ê҈ + ú � úû  êë 



 꾀   㡰

ᆠ鼀

�

�



ᆠ鼀

f㦨ᆠ鼀

Q

v v m㦨 Þ㦨 Þv㦨ᆠ鼀 u -

҈ ҈ ҈  ҈ ҈  + = = Þ + = Þ R =  ᆠ鼀 v u f R ҈ - R

O u

C v

r 

PO㦨OQ

é҈ ҈ ҈ ù = ( m - ҈) ê - ú f ë R҈ R û

҈ \ f㦨r r  ҈ = r r \Feq.㦨r

҈ ҈ ҈ ҈ = 㦨 + ÞFeq.㦨r r  r  r Feq ��

Q �鼀�㡰

Feq =

ᨨ 和㡰ᆠᨨ鼀� �ᨨ ᨨ ᨨ  ᨨ盐ᆠᨨ   ᨨ  ᨨ㜠ᆠᨨ ᆠ  矄

 ᆠ��  ᨨ  矄㡰 㡰 矄� � ᨨ鼀盐 ᨨ矄 �ᆠ ᆠ� �矄盐 ᆠ

- µ҈ µ µ - µ҈ + = u v R

é҈ ҈ ҈ ù = ( m - ҈) ê - ú f ë R҈ R û

҈ æ ҈ ҈ö - ÷ Þf㦨r 㦨 ҈�҈㡰 çè f -r ¥ ø ҈ ҈ ҈ ҈ ҈ + 㦨 + = ÞFeq.㦨r f f -r -r Feq

҈ æ nl ҈ ö öæ ҈ = ç - ҈÷ ç ÷ f è ns R R  ø øè ҈ ҈ æ nl öæ ҈ ö \ = ç - ҈÷ ç ÷ \ l㦨�  è ҈ ø è  ø

P

ᨨ ᨨ盐ᆠᨨ   矄 㡰

ᨨ 㡰  ᨨ㜠ᆠᨨ ᆠ  矄

�鼀� ᨨ鼀 泐ᆠᨨ  矄� �矄 � ᆠ �盐 泐 矄鼀├ ᨨ鼀盐

෌矄矄

b㡰

é ҈ ҈ ù � = (҈� - ҈) ê - ú = = r ë ¥ -r û ҈ ҈ ҈ ҈ ҈ = + = + = Feq f҈ f  r r

ᨨ  ᆠ�ᨨ  泐� �鼀�ᨨ ᨨ鼀盐

m2

҈ ҈ ҈ ҈ ҈ = + = + f f҈ f   -� 㦨҈�

ᨨ 턼㡰 ᨨ㜠ᆠᨨ   矄

\

m1

P=

\

҈ ҈ ҈ ҈ ҈ ҈ - = Þ = v u f v - f ҈ ҈ ҈ ҈ ҈ ҈ = Þ = +  - f f  

꾀�

盐矄� ᆠ 盐  �� 泐矄ᆠ盐ᨨ  �  矄�泐犨�  盐ᆠ 㡰 ᨨ犨ᨨ  矄ᆠᨨ鼀� �ᨨ 

æ҈ ҈ö éù ҈ Þ ҈� - ҈㡰 ç - ÷ = (҈� - ҈) ê ú = Þ f = r èr rø ër û r ҈ ҈ ҈ ҈ ҈  = + = + = Feq f҈ f  r r r

n

黨

F



 ᆠ ᨨ�ᨨ  㡰 �矄 ᆠᨨᆠ  㡰 ᨨ 矄 y� �  矄 ᨨ鼀盐





O B

꾀㜠錐㜠⼄矄錐ᔴ㜠㜠⼄矄 ␔  泐ᨨ ��  矄 ᨨ鼀鼀 �盐鼀ᨨ  矄鼀 �盐鼀 �  矄 ᨨ犨 矄   ᨨ鼀   �矄 ᨨᨨ矄� 犨     泐 ᨨ ��  矄 ᨨ鼀  矄ᨨ� 矄犨泐 ᨨ鼀  ᨨ鼀 㡰 꾀矄 m҈  m   泐 ᨨ  ��   � �    矄 犨�  ᨨ犨 矄   ᨨ鼀

WWW.JEEBOOKS.IN

P-279

Ray Optics and Optical Instruments

�

黨

ᨨ鼀⼄ ���㡰   �㡰

㡰 꾀矄m҈>m 泐ᨨ ��  � �  矄犨� 犨泐 ᨨ鼀  ᨨ鼀 ᔴ㡰 꾀矄 m 㦨 m    泐 ᨨ ��  ᆠᨨ鼀� � ᨨ盐  ᨨ鼀    矄 犨� ᨨ盐  泐 ��ᨨ  㡰 꾀矄m>m 泐ᨨ �� ᆠᨨ鼀� �ᨨ盐ᨨ   矄 �矄 犨泐 ᨨ鼀  ᨨ鼀 꾀㜠⼄矄錐㜠⼄錐ᔴ㜠⼄矄錐㜠⼄矄 ᔼ鼀� ᨨ鼀 泐ᆠᨨ ᆠ鼀�ᨨ 꾀㡰ᆠᨨ   矄 ᔴ㡰 ᆠᨨ ᆠᨨ㜠 ᆠᨨ   矄 㡰 ᔴ �盐鼀� � �  �鼀� �矄  꾀 �鼀��矄� � �泐 犨  ᨨᆠ�矄 ᨨᆠ盐矄 ᔼ鼀� ᨨ鼀 泐ᆠᨨ  鼀�ᨨ 㡰�矄犨泐矄�盐 ෌� f㦨鼀u 㦨鼀

҈ ҈ ҈ Þ v㦨҈鼀 = v -   ҈ ҈ ҈ ᨨ犨 �  �� � 矄 ᨨ鼀盐 - = 犨�鼀t v u f

Þ \

d㦨鼀

҈

Þ

�黨

du ҈ dv ҈ du = ҈ 鼀⏌矄 +  =  ��   dt dt dt v u  æ dv ö ҈㡰 ´ ҈ 㦨黨鼀⏌矄 çè ÷ø = dt 㡰 

-

 ᨨ鼀� �盐 ᨨ ᨨ ᆠ  �ᨨ ᨨ矄��ᨨ ᨨ  �鼀� 犨  矄㡰㦨黨鼀⏌矄

҈ ҈ ҈ + = f ҈ - d  + d ҈ ҈ ҈ + = ҈ -   +  f



\

f 㦨鼀

M

X

F A

B Y

� 㝐� �盐  ᨨ   ᨨ  ᆠ  � ᨨ   鼀� � �ᆠ�ᨨ

Y

��㡰 和矄ᨨ ᆠᨨ 矄盐ᆠ�ᨨ ᨨ y ��鼀 ᨨᆠᨨ ᆠ鼀�ᨨ ҈㡰 犨� ӸӸἘ �ᆠ盐ᨨ꾀矄盐ᆠ  Ӹ㦨ӸἘ

㦨�矄҈

 �矄   矄 ҈㡰 ᨨ鼀矄�鼀�ᨨ 졠꾀졠¢꾀¢  矄ᆠᨨ   矄 㡰 ᨨ鼀矄�鼀�ᨨ 졠꾀졠¢꾀¢ ud 꾀

҈

�㡰 和� ᆠY�矄ᨨ犨ᨨ ᨨ�ᆠ  �矄AB  Xᨨ  ᨨ  �鼀��矄 �    矄矄 ᨨ盐 ᆠᨨ   矄 和矄ᨨ ᆠᨨ 矄盐ᆠ�ᨨ ᨨ 泐 ��鼀 ᨨ 矄 ҈㡰 ᨨ� XY �矄矄 矄 泐ᨨ��� � � ᨨ鼀 矄ᨨ盐ᆠ X 鼀� � �鼀�Y和� ᆠ 泐�矄盐 �  矄矄� �  ᨨ盐�   矄  ᨨO�矄 ᨨ�ᆠᆠ ᨨ   矄犨 Y҈OY �ᆠ盐ᨨAB 㡰 犨泐 ᨨ鼀XᨨAB XMᔼ矄�├矄Y҈OY Mᨨ� MYᔼᆠ盐矄AB F �矄�矄  ᨨᆠ盐矄ᨨ  ᆠᨨ   矄

udv vdu v dm = dt  dt 鼀� � �ᆠ�ᨨ m㦨 \ u dt u - 㡰 黨㡰 - ҈㡰 ҈㡰 -҈ = -�矄 㦨 㡰 

�

҈

和盐矄�盐� � �矄盐� ⼄ �㡰 v + u = f  

矄� � 矄 ᨨ鼀盐

\

҈ ҈ ҈ ҈ + = + v + d u - d v u ҈ ҈ ҈ ҈ + = + ҈ - d + d  + d - d ҈ - d  + d

Y'

N M

v 졔d

X F

A O

҈

C

B

Y



졠¢ 꾀¢¢

d u



ᔼ鼀� v

҈鼀



꾀¢

u졔v㦨҈鼀

鼀� � �ᆠ�ᨨ ᨨ  矄 ҈㡰�矄 �� 㡰

 �㡰

\

 ��㡰

v + d 㦨 u - d

㡰 ᨨ� YἘX    � �ᆠ盐矄 � ABᨨ� O

ᨨ� O�矄  ᨨ ᨨ 鼀�ᨨ 㡰 ᨨ� X Yᔼᆠ盐矄AB ᨨ� C �矄ᨨ� C�矄  ᆠ ᨨ ᆠ盐盐ᨨ  鼀�ᨨ 㡰 犨XMᨨ � ᆠ� �矄 ᨨ�  MᨨY � ᆠ盐ADF  ᨨF�矄  ᨨᆠ盐矄ᨨ ᆠᨨ ᆠ鼀�ᨨ �㡰  犨ᨨ�  �ᆠ 矄ᨨ ᆠᨨ   矄҈ 犨� ᨨ鼀 犨ᨨ 矄�鼀�矄 S҈   Sᨨ    矄ᨨ盐ᆠ S  ⼄盐 �矄 ᆠ 矄 �鼀�矄 S҈   S 犨�  矄 犨ᨨ ᆠᨨ   矄ᨨ盐ᆠ矄 u L҈

v S҈

ᨨ鼀⼄ �㡰  ��㡰

u =  + d v㦨҈d

S

꾀泐� � 矄 ᨨ鼀盐 ᨨ  矄 ҈㡰

҈ ҈ ҈ + = v + d u - d f

 ���㡰

L ҈�鼀

꾀�� 泐� � 矄 ᨨ鼀盐 ᨨ 矄 㡰

҈ ҈ ҈ + = v u f

O

 �㡰

A

d



O

鼀 S

D ҈鼀

ᨨ 矄L҈ L u㦨҈�鼀v㦨䁸f 㦨졔҈鼀

WWW.JEEBOOKS.IN

EBD_8341 P-280

Physics

҈ ҈ ҈ ҈ ҈ ҈ ҈ ҈ Þ = + = - = + v u f v f u ҈ -҈� \ v㦨鼀

Q

v � 鼀� � �ᆠ�ᨨ m㦨 u  㦨 \ m㦨 -҈�



\ 犨ᨨ�鼀�矄S҈ Sᨨ S犨� ᨨ鼀 鼀 ᨨ鼀   矄 S҈犨��鼀鼀ᨨ�矄ᨨ�ᆠ �矄矄m㦨 S犨��鼀鼀ᨨ犨�矄ᨨ�ᆠ �矄矄m㦨 \ d 㦨S҈S㦨҈�鼀鼀㦨҈�맔҈鼀 D㦨҈㦨҈鼀 l 㦨� 鼀㦨�맔҈黨鼀㦨�맔҈䰘鼀

Dl d -䰘 ҈㡰 � ´ ҈ 㡰

\

� �犨�  b㦨

ᨨ

b㦨

҈� ´ ҈

-

矄� r>

\ 泐 PR 犨�  ᨨ泐 �    ᆠ  ᨨ � RQ 졠

ᆠ � �Q 泐犨� ᆠ � 鼀 ᔼᔼ ᆠ 泐犨� 盐�鼀泐 ᆠ ᆠ├� 鼀 �盐鼀ᔼᔼ  矄盐 ᆠ�矄  ᆠ� �矄盐 ᆠ\R㦨¥

O

Ҙ Ҙ Ҙ -Ҙ Ҙ Ҙ - ҈ +  =  ҈ Þ- ҈ +  = u v R - -

Ҙ  = Ҙ҈ 

҈ 맔҈鼀 

æ҈ è

Ҙ Ҙ Ҙ -Ҙ - ҈+  =  ҈ u v R

- ö

÷ 㦨҈鼀 ø

\ OA㦨҈鼀 ��㡰 ��ᨨ ᨨ OA 犨� �犨 L҈ L ᔼ  �犨 L҈ L�矄 盐ᆠ d犨� ᆠ矄 Q ҈

b㦨

Dl \ b犨�� ᆠ矄 d

\ �矄 ᆠOA犨�� ᆠ矄 泐ᨨ ��  �矄 矄 ᨨ鼀鼀 �盐鼀ᔼᔼᨨ鼀 �盐鼀ᔼᔼᔼ� ᨨ鼀  矄ᨨ鼀 �盐鼀 ᔴ矄 �㡰Wh nn҈ �.e. nn҈n

æ n҈ ö æ n ö n n҈ ᨨ 矄� ҈ ç n ÷ 矄� ҈ ç n ÷ < è ø è ø n n 졠�ᨨ盐矄泐nn   �q�矄�   ᆠ��ᆠ � ⼄盐�  ᨨ   泐 矄矄� � ᨨ鼀 鼀 �盐鼀 ᔼᔼ ᨨ 鼀 �盐鼀 ᔼᔼᔼ

 ᨨᨨ�   ᆠ�ᨨ 犨�矄ᨨ├ᆠ犨  泐 矄�├矄 犨�    矄鼀  �    �  ᆠ ᨨ  鼀 �盐鼀 ᔼᔼ  鼀 �盐鼀 ᔼᔼᔼ ᔴ矄 ��㡰nn҈b盐nn

泐犨�� ᆠ � 鼀 �盐鼀ᔼᔼᔼ矄  �q犨� ᨨ犨 矄矄   ᆠ��ᆠ �⼄盐�  ᨨ鼀 �盐鼀ᔼᔼ 鼀 �盐鼀ᔼᔼᔼ � 㝐 ᔼ

R

Þ -

҈ Ҙ ⏌ Ҙ҈ Ҙ ⏌ Ҙ҈ 㡰 - ҈ + = u v R

Þ

-

҈ ⏌  ⏌  -҈ + = Þ 㦨�ᆠ鼀 - -� ⏌  R

v

u

I O

ᨨ犨 泐� �  Ἐ矄 鼀├ ᨨ鼀盐

æ ҈ ҈ ҈ö  ҈ ҈ö = m - ҈㡰 ç - ÷  = æç - ҈öæ - ÷ \f 㦨䰘�ᆠ鼀 ÷ç f R R è ҈ è  øè � µ ø ø

ᨨ

㝐 ᔼᔼᔼ

 �㡰

꾀��   ᆠ�ᨨ ├矄ᆠ ᨨ鼀矄 �ᆠ矄盐 ᆠ

和� ᆠᨨ� A�矄 � 鼀 �鼀 OA㦨b㦨맔 ç ´҈

v I

u

\ ᨨ b㦨

n҈ n  Þ 矄� r>矄� �'' Þ r>�''



�㡰

 矄� ᆠᨨ ᆠᨨ㜠ᆠᨨ   矄 矄�├鼀�ᨨ

犨 ᨨ矄 ᨨᆠ � 

҈  ҈ = + f f҈ f 

 㦨ᆠ鼀   f㦨 ᨨᆠ � ᨨ ᆠᨨ ᆠ鼀�ᨨ㦨 㦨҈ᆠ鼀 

f҈㦨 ᨨᆠ � ᨨ ᆠᨨ ᆠ矄盐 ᆠ㦨

r

r R҈㦨ᆠ鼀

P

G q

㝐 ᔼᔼ

F R 㦨ᆠ鼀

꾀泐� � 和 Ἐ矄 犨  P

n 矄� q n 矄� q = \ 矄� r㦨 n 矄� r n

Q n>n\ r >q ␔    ᆠ 泐PR鼀矄 ᨨ盐 泐DE��矄� � ᨨ鼀  矄鼀 �盐鼀ᨨ鼀 �盐鼀 ᆠ 泐犨� ᨨ泐�  泐 ᆠ DE� �矄 �ᨨ � ᆠ�  ᆠ�矄鼀ᨨ    ᆠ��ᆠ � ᨨ鼀 ᔼᔼᔼ ᔼ 矄� �ἘἘ㦨

n҈ n

\

҈  ҈  = + = - Þf 㦨䰘�ᆠ鼀  f - -҈

P� ᆠ  �矄 ᆠxᨨ  ᨨ�ᆠ �矄矄盐ᆠ  �矄 �鼀��矄 ᨨ鼀  矄鼀ᆠ�u㦨v㦨x 矄� �鼀�ᨨ ᨨ鼀盐

҈ ҈ ҈ ҈ ҈ ҈ = + Þ = + f v u -䰘� - x - x

\

x㦨҈�ᆠ鼀

WWW.JEEBOOKS.IN

P-281

Ray Optics and Optical Instruments ��㡰

␔  ᆠᨨ ᆠ�矄 � 犨� 犨ᨨ m㦨

  



ᨨ犨 ᨨ 矄�├� �犨�    ᆠᨨ ᆠ 矄盐 ᆠ   泐 �矄 �矄  ᆠ  ᨨ鼀  矄盐 ᆠ 和ᨨ y     �矄 ᆠ ᨨ �      矄盐 ᆠ犨� ᨨ鼀�矄�鼀� �矄 ᆠ 㦨mh㡰 ᨨ鼀�

æ 꾀 + d鼀 ö æ 䰘 + d 鼀 ö 矄� ç ÷ 矄� ç ÷   è ø= è ø 盐 m = 䰘 矄� 꾀 ⏌  矄�

 d鼀 ö � æ 矄�

䰘 = ° +   çè  ÷ø

 y  

m m҈ m - m҈ = v u R ҈� ⏌ ҈� - ⏌ = - -  x -  ҈  ҈ = ᨨ x㦨҈ᆠ鼀 x  

矄� �

ᨨ

 �

m 鼀 ᆠ 

� �  �矄 m 鼀 �矄矄矄   = ҈䰘  

盐d鼀犨�矄矄   矄ᨨ

\ Dx㦨x҈x㦨҈�ᆠ鼀҈ᆠ鼀㦨҈҈ᆠ鼀 ᨨ鼀 ��盐 �㡰 �矄 ᨨ ᆠ�ᨨ   ᨨҘ҈㦨Ҙ ᨨ鼀 ��盐 ��㡰  ᆠᨨ   矄 矄矄 ��� � 矄

 ᨨ ҘҘ\m҈m ᨨᆠ �  ᨨ  ⼄盐� 鼀�ᨨ

�

m
矄� ҈ êm 矄� 꾀  矄�

Mw  ⏌   = = Mg ⏌  黨

 矄� ᔴ㦨

꾀泐� � 矄 矄 犨  Ӹ ҈맔矄� q㦨  矄�  㦨  矄�  䰘� ᔴ㡰 ᨨ鼀⼄ �㡰

 �㡰 

 ��㡰 䰘�    Ӹ 黨黨 ᔴ  q  黨 ᔴ R× ᔼ  =



WWW.JEEBOOKS.IN

P-283

Ray Optics and Optical Instruments ᨨq㦨

\ r҈ = A  矄�

 =  矄� 䰘�°  ᔴ㡰 \ ᔴ㦨�  ᨨ鼀⼄ ��㡰 = ҈䰘

 矄� �° =

m=

  A

҈







 ᨨ 

 矄� ° = 矄� r Þ r㦨�

҈

r 㦨�ᨨ

B

C





dm = �҈ - A   d m = A \ �҈㦨꾀㦨e 㦨꾀 \

�҈ 

턼 ҈







e

A



� r҈ = ҈ 

 ᨨ ��  ᨨ犨 �ᆠ m҈҈ 犨� ᆠ �  ᆠ꾀犨 矄 B 盐   �  ��  犨� 矄盐  ᨨ �    ᆠ�ᨨ  㡰 ®  ␔    泐 矄 ᨨ鼀 ᆠ �盐ᨨᆠ├ᨨ �矄鼀   �ᨨ � ᆠ�  ᆠ> �ᨨ  ᆠ�ᨨ 矄ᨨm>m҈

泐  鼀ᨨ矄犨泐 ᨨ鼀  ᨨ鼀犨  �鼀�矄ᨨ盐 ᨨ  ᆠ �盐ᨨᆠ├  ᨨm>m ® �꾀矄 �矄 ᨨ ��ᨨ ᨨ  泐矄�鼀�矄ᨨ盐ᨨ   �矄鼀\m㦨m҈ ® 꾀矄 泐鼀�矄ᨨ盐ᨨ �矄鼀�鼀ᨨ矄犨泐 ᨨ鼀 

ᨨ鼀\mm҈꾀  泐鼀ᨨ矄犨泐 ᨨ鼀  ᨨ鼀矄 � 鼀�矄 ᨨ盐 ᨨ    ᆠ �盐 ᨨᆠ├ \m>m ® � 꾀 �矄鼀矄盐 ᆠᨨ�   ᆠ�ᨨ  矄├

ᆠ \ᔴ��ᆠ �� >ᔴÞ矄� � >矄� ᔴ Þ



m >  \ m >  m ҈   m҈

҈

ᨨ ᨨ �    ᆠ�ᨨ  ᨨ  �  ᆠ 꾀

҈

Ҙ



҈ = = 矄� �㦨矄� C҈ 㦨 ҈ =  Ҙ Ҙ

�ᨨ 犨 m A

m=

҈ ҈ = = ҈҈ 矄� C 矄� �°

�=45o

ᆠᨨ ��ᨨ �矄 ᨨ鼀� �盐鼀 ��ᨨ ᔼ  �矄ᆠ矄 泐� 矄�   �矄鼀ᆠᨨ鼀矄ᨨ矄  ᨨ  �鼀 泐  泐� 矄�  �矄鼀犨�  矄ᨨ  �矄鼀�矄  T盐錐 ᨨ �� ᨨ矄� 鼀� ᨨ盐� 犨 �ᆠ  �� 矄矄矄 矄 ᨨ盐   ᆠ��  �  ҈ 和� ᆠ �矄鼀 �矄 ᨨᨨ犨犨 � ᨨ 矄ᆠ盐鼀 矄 ᨨ  ᆠ�ᨨ

  ᨨ �矄矄�ᨨ  ᨨᆠᆠ盐   �ᆠ├ 矄矄 ᨨ  �矄矄 矄矄  ᨨ盐� 犨 �ᆠ  �矄鼀�矄鼀 ᆠ  �ᆠ  ᆠ 㡰 ᨨ鼀� �鼀盐鼀 ��ᨨ

꾀 �҈㦨

A 

҈� - ҈㡰 ° = ° ҈䰘 - ҈㡰

㡰   ᆠᨨᨨ盐 鼀 ᨨ  ��  ᨨ犨 �ᆠ  � > c 犨� � ᨨ �    ᆠ�ᨨ 

� ᨨ  �ᨨ � ᆠ�  ᆠᨨ �   ᆠᨨᨨ盐犨�矄盐 ᨨ�   ᆠ�ᨨ

ᨨ犨 �ᆠ m>҈҈

 + fm = �° Þ fm = ° 

҈㦨㦨 矄泐㡰㦨

A =

 Ҙ҈҈㡰A҈㦨 Ҙ҈㡰Aᨨ

m=

(Ð꾀㦨  ᨨ ⼄盐�� �㡰

҈黨

é -҈ ҈ ù êm 矄� A - 矄� m 㡰 ú ë û

矄� �҈ -҈ \ �҈ = 矄�

矄� r҈

ᨨ 鼀� �鼀盐鼀 ��ᨨ   ᨨ盐�  �矄ᨨ矄ᆠ矄 �矄鼀 � ÐB㦨Ðᔴ턼ᔴ ᆠ㡰 꾀 �ᨨ  ��ᨨ  ᨨ   �矄�矄鼀P҈ d҈㦨 Ҙ҈҈㡰A҈ 꾀 �ᨨ  ��ᨨ  ᨨ 矄ᆠᨨ �矄鼀 P d㦨 Ҙ҈㡰A ᨨ �矄矄�ᨨ  犨� ᨨ盐 ��ᨨ  d 㦨  \

æ A + dm ö æ  + m ö 矄� ç ÷ 矄� ç è  ÷ø  è ø \  = m= 矄� A  矄�  

Þ

҈ö çm÷ è ø

꾀泐� �  和 Ἐ矄 犨  ἘἘ

\ 㦨҈� 꾀 ᆠ꾀ᨨ �矄鼀泐 矄

ᨨ鼀泐盐矄� �和 Ἐ矄犨 ᨨ   ᆠ�ᨨ AC Ҙ矄� �㦨 ҈㡰矄� r

꾀 �ᨨ  ��ᨨ  ᆠAC 㦨�  㦨҈�

-҈ æ

矄� �҈ 矄� A 矄� A ⏌  ᆠᨨ矄 A ⏌  = =  =  ᆠᨨ矄 A ⏌  矄� r҈ 矄� A ⏌  矄� A ⏌ 

␔  鼀� 泐 � �ᨨ 矄盐 ᆠ

矄� 黨° ҈ -҈ æ ҈ ö m= = Þ r = 矄� ç ÷ 矄� r 矄� r èmø 꾀

҈ 

 Þ � 㦨ᔴ҈㦨�



m҈ =  B

A � � C

m =  m = 

D

ᨨ ᨨ �    ᆠ�ᨨ  ᨨ  �  ᆠ ᔴ

�҈ 



盐r҈졔r㦨A\r҈㦨Ar



m ҈  Þ�㦨C㦨 矄� � = 矄� C =  =  =  m m

 ᔴ

  ᆠ 鼀� �鼀盐鼀 �ᨨ � ᆠ�  ᆠ矄盐ᆠ   ᨨ�    ᆠ�ᨨ ᨨᆠᆠ盐矄ᨨ  ᨨ  矄盐 ᆠ矄�矄 

WWW.JEEBOOKS.IN

EBD_8341 P-284

�

Physics ᨨ犨��矄��  r㦨qc \r҈㦨Ar㦨 � qc㡰 꾀泐� � 和 Ἐ矄 犨  ᆠAB

ᨨ  ᆠ�ᨨ   �矄 矄盐 ᆠ �    ᨨᆠ ᆠ   � � �泐  �鼀�  �矄 ᆠ�ᨨ 犨� ᨨ鼀  �矄 ᆠv҈

m  m҈ m  - m҈ = +R v҈ - ¥

 �㡰

矄� �҈ n㦨 矄� r҈

ᨨ ᆠ�ᨨ 矄ᆠᨨ 矄盐 ᆠ

m m  m - m  = +R v v҈ 

 ��㡰

m



v

㦨矄� ҈

 ᨨ ᨨᆠ �  ᨨ  ��  矄矄泐矄鼀㦨

Ҙ R Ҙ - Ҙ҈

ᨨ

l 

æ 黨 ´ ҈

l㦨 ç

è

= ҈� +

î 

l 

犨 l�矄�  鼀㡰

㦨 鼀

ᨨ \



D C 䰘 n2 n1  r 㦨



 B

A

矄� � n҈㦨 Þ 矄� �㦨n҈矄� r 矄� r é ҈ ´ ҈ ù ҈ + ҈ ê ú´ Þ 矄� �㦨 㡰 ûú  ëê

䰘

Ql㦨 鼀㡰

矄� �㦨 è ø 

\

꾀 �ᨨ � ᆠ�  ᆠ�㦨矄� ҈ ç ÷ è ø

�㡰

꾀 ᆠAC

æ ö 

æ ҈ö n ᔴ��ᆠ �qc㦨矄� ҈ ç n ÷ ᨨ 矄� qc㦨 ҈ n è ø

矄� �҈ 矄� r҈

矄� �҈ 矄� �° æ ҈ ö 矄� �҈㦨 ҈�㡰 ç ÷ 矄� �҈㦨黨� è ø

҈�㦨

\ �҈㦨矄� ҈ 黨�㡰»䰘 � ⼄盐�  �ᨨ � ᆠ�  ᆠ�㦨䰘

矄�盐�ᨨ ᆠ 矄 ᨨ犨 矄�   ��盐 A � 㦨 A㦨  d㦨 e㦨䁸 꾀 A졔d㦨�졔e Þ e㦨A졔d� 㦨 졔  㦨 �  ᆠ   鼀�  泐 �矄 r

ᨨ鼀ᨨ  ᆠ ᨨ鼀犨 �ᆠ �鼀�矄 B ␔  e㦨r¢㦨 r¢졔r㦨A㦨r㦨  ᨨ鼀和 Ἐ矄犨 ᆠ��  ᨨ �矄鼀

Ҙ=

æ ö

ᨨ

n

ü n  - n҈ - n҈ 㡰 ý þ

ᨨ犨泐� �和 Ἐ矄犨 ᆠAB犨 n㦨

E



C

��㡰  n҈ ¹ n ᆠ盐矄 n҈  n �矄�� 㡰 矄ᨨ ᨨ 泐ᨨ 矄矄 盐 �  ᨨ盐� AC r㦨 泐^ᨨ  ᆠAC㡰 ᨨ r҈㦨Ar㦨�  㦨�

A ° r㦨 = 㦨  



�

ì ü æ n҈ n҈ ö÷ ï ï n ç ҈ í ý n  n ÷ø ï ïî  çè þ

ì ҈

㡰 ᨨ�� ᨨ 犨 �  l㦨 鼀 ᆠᨨ鼀� �ᨨ ᨨ �矄鼀ᆠ矄矄矄� ��矄鼀矄  �├ �矄ᨨ矄ᆠ矄� �ABE 矄矄 ᨨ犨 �  ��盐꾀 鼀� �鼀盐鼀 ��ᨨ  泐� 矄�   �矄鼀 犨�ᨨ 矄 \

n

�҈㦨矄� ҈ í

҈ ´ ҈-

 ö ҈⏌ 

÷ � ø



�矄�矄 ⼄盐�  �ᨨ � ᆠ�  ᆠ �҈㡰 ᆠAB ᨨ犨 �ᆠ  泐矄�├矄  ��ᨨ  ᆠACᆠ��ᆠ ��矄

㡰  泐矄 � ᆠ�     泐 � ᨨ    �  ᆠ ᔴ 矄矄  ᨨ盐� 犨� ᨨ盐 � � �矄矄盐 ᆠ� n҈㦨n

҈ ´ ҈-

r

ü ҈ - 矄�  qc - 矄� qc 㡰 ý î  þ

␔  � ᆠ�  泐矄�鼀� ᨨ鼀  ᨨᆠ盐矄

҈졔



ì n

m R Ҙ Ҙ - Ҙ҈ Þ v㦨 m - m =  ҈ v R



�҈

㦨矄� ҈ í



꾀 � �⼄ �㡰  ��㡰

�

ᨨ 矄� �҈㦨n矄� r҈ B \ �҈㦨矄� ҈ n矄� r҈㡰 和盐矄�盐� �盐ᨨ r҈犨� �҈㦨矄� ҈{n矄�  � qc㡰晤 㦨矄� ҈{n 矄� � ᆠᨨ矄qcᆠᨨ矄� 矄� qc㡰晤



I

m

A

d rἘ

e C

矄� � 矄� ° ⏌ = = =  = ҈䰘 矄� r 矄� ° ҈⏌ 

Topic-5 : Optical Instruments ҈

㡰 ᨨ 矄ᆠᨨ

盐 �  㡰㦨fᨨ졔fe㦨  鼀� � �ᆠ�ᨨ  m㡰 =

fᨨ = � Þ f  = � fe fe

WWW.JEEBOOKS.IN

P-285

Ray Optics and Optical Instruments \ fᨨ㦨�ᆠ鼀 f㦨҈ᆠ鼀  ᆠ ᨨᆠ �  ᨨ 泐㜠�ᆠf㦨҈ᆠ鼀 

㡰 꾀ᆠᆠᨨ � �⼄盐矄�ᨨ M㦨䰘� L=҈�鼀鼀f㦨�鼀鼀 fe㦨䁸 矄� �鼀� � �ᆠ�ᨨ  M ;

Þ 䰘� =

�

෌�  �矄 ᆠ犨  ᨨᆠ� 泐�ᆠ㦨҈�ᆠ鼀 \ �矄 ᆠᨨ �鼀� ᨨ鼀 泐 ᨨᆠ� 㦨҈�㦨҈ᆠ鼀  盐    ᨨᆠ �矄 ᆠ ᨨ鼀 ᨨᆠ�    ᨨ ᨨᆠ�  矄

L æ Dö ç҈ + ÷ f è fe ø

҈� æ � ö ç҈ + ÷ f e ø QD㦨�ᆠ鼀㦨�鼀鼀㡰 � è

Þ ҈� = ҈ +  

� � = ҈䰘 »  mm  Þ fe = fe ҈҈�

b㡰 꾀矄ᆠᨨ鼀� � �矄泐鼀├� � ᨨᆠ� �ᆠᨨ矄 ᆠ㡰  � �ᨨ  犨� ᨨ盐 矄  � �犨ᨨ 犨�  矄  � �  犨� 矄犨 盐矄 㝐� �鼀盐鼀  � �矄⼄盐� ᨨ 鼀�  ᆠ��  ᨨ �矄矄矄盐矄� �� �鼀�ᆠᨨ矄ᆠᨨ ᆠ㡰 㝐� � 泐� � ᨨ犨 ᨨ  矄ᆠᨨ

MP =

Þ 黨

҈ ҈ ҈ - = v u f ҈ ҈ ҈ ҈ ҈ ҈ � = Þ = Þ u = - ᆠ鼀 v u f � u ҈ 



ᨨ ҈

a=

� ҈  = ҈ 

\

b 㦨 q 㦨 㝐 맔 a =  ´

꾀矄ᨨ 鼀� � �ᆠ�ᨨ   m҈ =

҈ ҈ ҈ x = Þ v҈ = v҈ - x ҈ x -҈

҈ v҈ = u҈ x -҈

ᨨ  矄ᨨ泐㜠�ᆠ  �矄�矄ᆠ� �矄ᨨᆠ

꾀¢

꾀 꾀¢¢ 졠

x ö æ \ u = -  - v҈ 㡰 = - ç  ÷  v㦨�ᆠ鼀 x -҈ ø è

쟼 

¢ ¢¢



ᨨᆠ �鼀� ᨨ鼀 泐҈矄 矄 �鼀� ᨨ鼀 泐  矄

쟼泐㜠�ᆠ

ᆠ鼀

ᨨ �矄  矄ᨨ ᨨᆠ� =

Q D㦨� ᆠ鼀矄 �矄 ᆠᨨ  �矄� ᆠ�矄�ᨨ 㡰㦨  ᆠ   鼀� � 泐� � ᨨ犨 ᨨ    ᆠᨨ鼀ᨨ盐  鼀�ᆠᨨ矄ᆠᨨ �矄  ᆠ㡰  � 鼀 � �鼀� �  ᆠᨨ鼀ᨨ盐  鼀�ᆠᨨ矄ᆠᨨ �矄  �   鼀� � �  ᨨ

O I҈ I



矄� � 矄 ᨨ鼀盐

 � v D ´ ´ 㦨 ҈�  u f e



I

졠ᆠ�

㝐� � �ᆠ�ᨨ   � � �泐

䰘

�ᆠ鼀 I҈

x

҈ ҈ ҈ = ҈ v -҈�㡰

 = �ᆠ鼀 

㡰 꾀ᆠᆠᨨ � �ᨨ⼄盐矄�ᨨ  � �鼀��v㦨�ᆠ鼀 f㦨҈ᆠ鼀鼀� � �ᆠ�ᨨ m㦨m҈m㦨҈

O

҈ ҈ ҈ Þ v㦨ᆠ鼀 = v ҈ ҈�

M ¥ 㦨 -

\N =

f㦨҈ᆠ鼀

㡰 ෌� f㦨҈ᆠ鼀錐fe㦨ᆠ鼀 u㦨҈�ᆠ鼀錐M¥㦨䁸

Þ

� N =  

fe

҈  = = ҈�   

҈° ; ° ᨨ b = ҈� ´ p

҈ ҈ ҈ ᨨ鼀 Þ = f  v u

�㡰 ෌�  � ᨨ ᆠᨨ鼀ᨨ盐 鼀�ᆠᨨ矄ᆠᨨL㦨҈ᆠ鼀 ᨨᆠ  �  ᨨ  ᨨᆠ� f  㦨 ҈ ᆠ鼀  ᨨ 泐㜠�ᆠ fe = �ᆠ鼀 u㦨fe㦨�ᆠ鼀 � �鼀� ᨨ鼀  � � �泐 ¥ 㡰ve㦨 ¥ v㦨҈�㦨� 矄� � 矄 ᨨ鼀盐

b  �矄盐  泐�鼀�泐�ᆠ㡰 a  �矄盐  泐ᨨᆠᨨ ᨨᆠ�㡰 fe

-҈ ҈ ҈ ҈ ҈ ҈ + = + = ᨨ uᨨ ҈  u v f  -҈ ҈ ҈ � ҈ = - = \ uᨨ = - = - ᆠ鼀 uᨨ  ҈ ҈ �

-

f ᨨ ҈� =  㦨  꾀矄ᨨ MP =



-҈ ҈ ҈ + =  Þ u㦨ᆠ鼀 ue µ  [Q � �鼀� ᨨ鼀 泐 泐�ᆠµ桌

Þ

㡰 fᨨ㦨ᆠ鼀 fe㦨ᆠ鼀 矄� � 矄 ᨨ鼀盐 ᨨ泐�ᆠ

꾀 �盐鼀� � �ᆠ�ᨨ   m A =

� D = u  u  

ᨨ鼀� � �ᆠ�ᨨ  m = m҈mA = ҈

� æ ҈ öæ ö ç ÷ç ÷ = ҈ è x - ҈ ø ç  - x ÷ x -҈ ø è � Þ = ҈ Þ ҈ =  x - ҈㡰 -  x  x - ҈㡰 - x Þ 䰘 x = ҈ Þ x =

҈ 䰘

WWW.JEEBOOKS.IN

EBD_8341 P-286

Physics

æ ç Þ u = - ç  çç è

ᨨ犨 ᆠ�ᨨ 犨�ᨨᆠᆠ盐ᆠᨨ ᆠ鼀�ᨨ ᨨ �矄IἘ 矄 矄 ᨨᆠ�矄 ᆠᨨ ᨨᆠ ᨨ鼀鼀�ᨨ u㦨 ҈�졔�㡰㦨ᆠ鼀

҈ ö 䰘 ÷ = -҈黨 ÷ ҈ ÷ � -҈÷ 䰘 ø

é ë

꾀�� 盐矄� � 矄 ᨨ鼀盐 ᨨ泐㜠�ᆠ

҈ ҈ ҈ � ´ ҈黨 = Þ fe = » ᆠ鼀 ҈黨 fe -� ҈ � ҈҈

҈

҈ ҈ ҈ ҈ ҈ ҈ = + Þ = + f v u f - -

 矄ᨨ� �ᨨ犨 ᨨ   ᆠᨨ  鼀�ᆠᨨ矄ᆠᨨ �矄 ��   

 ᨨ  ᨨ�ᆠ鼀�ᆠᨨ矄ᆠᨨᆠ盐矄 犨 � ᨨ ᆠᨨ 矄 �矄矄鼀   犨 � ᨨ �矄���  bᆠ 㡰ᔼ  矄ᨨ ᨨ鼀�ᆠ矄ᆠᨨ  �矄 ᆠ犨   ᨨᆠ�  矄   泐�ᆠ  矄 L㦨f졔 f㦨҈졔㦨҈鼀

f ᨨᆠ� f 泐 �ᆠ

=

-҈ = - 

�鼀�矄  泐 矄ᨨ ᨨ鼀�ᆠ矄ᆠᨨ�矄�  꾀矄ᨨ  ᨨᆠ��矄�  泐�ᆠ 㡰 ᔼ  矄ᨨ ᨨ鼀�ᆠ矄ᆠᨨ犨    � �鼀��矄 ᨨ鼀  � � �泐 꾀 �盐鼀� � �ᆠ�ᨨ

\



�





fᨨ = � Þ f ᨨ = � f e 㝐㦨 fe

V

䰘



҈  ᔼ n



ᔼᔼᔼ n 

ᔼᔼ n 

æ ҈ö 

G

Y

O

qC

R

q

a a

b

҈㡰  � ��ᆠᨨ 泐��     �  ᆠᨨ 泐�� ᆠ鼀 ᨨ鼀 ��盐DAFB DCFD矄�鼀� 꾀

 ҈ d = = D  ҈

ᔼ

ᔴ 



ᆠ鼀



ᆠ鼀

꾀矄 �矄 ᨨ �泐ᨨ矄矄\ID㦨Id \꾀��  矄�泐ᨨ ��  �矄 ᆠᆠ鼀 I 㦨

b

é    ù � = �ᆠ鼀  êQ 꾀   = ú m ҈ ë û

æ ҈ ҈ ҈ö = m - ҈㡰 ç - ÷ =  f è R҈ R ø

҈ \ �ᨨᨨ  = =  ҈ D

ᔼ n 

ᆠ㡰 �鼀�I Ἐ ᨨ �矄 ᆠ�ᨨ  �犨   泐ᆠᨨ鼀矄 ᨨ盐ᨨ �⼄盐� 㡰�矄   ᨨ

=

B

d





 矄� a㦨 矄� b㦨 矄� 黨º   

ᨨ q㦨矄� ҈ ç ÷ è ø

I

꾀� ෌ �� 㡰

 ᆠ 泐ᨨ犨 ᨨ �     ᆠᨨᨨ盐矄 ᨨ  ��  ᨨ 犨 �ᆠ qC>� ᆠ�  ᆠ �犨�ᆠᨨ鼀ᨨ盐ᨨ� ᆠ㡰 和� ᆠ ᨨ  矄盐 ᆠ矄  矄鼀  �盐矄 ᨨ  ᆠ盐盐 R҈㦨R㦨Rᨨ  矄鼀矄�  ᨨ �矄矄�ᨨ 犨�ᨨᆠᆠ盐

\

 �ᨨ  ᆠ�ᨨ �  ��ᨨ ᔼ鼀盐矄黨 矄 鼀 盐矄鼀�矄矄矄 � � ��ᨨ ᔼ 矄� q㦨

҈ ҈  Ҙ µ Ҙ l

ᨨ ᨨ �矄矄�鼀

ᆠ㡰 ␔   �� �矄� ᆠ�  ᨨ �矄矄㜠 �  ᆠ� � ᨨ鼀 �矄矄  �矄矄  ᆠ��ᆠ �矄鼀ᨨ �� 犨�  ᆠ    鼀ᨨ矄  犨�  矄鼀�  ␔    ��  �矄� ᆠ�  �   ᆠ��ᆠ ���矄 ᆠᨨ鼀  ᆠ  ᨨ�   ᆠ�ᨨ 㡰矄ᨨ奠 矄鼀�矄矄�ᨨ

 ҈奠 ᆠ�ᨨ 

矄 ᆠ ᆠ�矄�ᆠ矄  �ᆠ  �  ᨨ�ᨨ  ᆠ㡰 b㡰 ᨨ  ᆠ�ᨨ    �  ᆠ矄 ᨨ鼀 和 Ἐ矄犨

\

矄� qC =

෌矄矄

L㦨 fᨨ + f e =  Þ � f e + f e =  ᨨ fe㦨ᆠ鼀 fᨨ㦨�fe㦨�맔㦨ᆠ鼀

  矄� q =

ᆠ㡰

l � ᆠ矄矄

Topic-6 : Miscellaneous (Mixed Concepts) Problems ҈

\ f 㦨҈҈ᆠ鼀 㡰 �矄 ᆠᨨ �盐�鼀� ᨨ鼀矄盐 ᆠ㦨ᆠ鼀

泐矄ᆠᨨ鼀� � ᨨ鼀 ᨨ� ᨨᆠ ᨨ  �矄矄㜠��  ᆠ

ᨨ鼀泐   ᆠ矄矄盐 �   ᨨ� 犨ᆠ   ᨨ   ᆠ 泐矄ᆠ├犨 矄 �鼀�犨� ᨨ鼀    ᆠ  ᨨ 泐 ᆠ㡰 ⼄盐 ᆠ泐 ᨨ矄 ᨨᆠ  �犨� ᆠ  �ᨨ 鼀 �盐鼀 \ ⼄盐 ᆠ泐ᨨ  矄ᨨ盐 �  犨 㦨 ⼄盐 ᆠ泐   �  � 㦨  

\ 矄� qCµ l ᨨ �� 盐ᨨ l ᆠ��ᆠ �qC矄ᨨ� ᆠ矄矄

꾀    矄�ᨨ  犨    ᨨᆠ�矄   泐㜠�ᆠ \

� �矄   ᨨ  �鼀� ҈

矄� �鼀�ᨨ ᨨ鼀盐

҈ l used

꾀 �盐鼀� � �ᆠ�ᨨ 㦨

҈

␔ 

矄ᨨ� �ᨨ犨ᨨ 鼀�ᆠᨨ矄ᆠᨨ

µ

� ù û

 v = - ê҈� + ҈ ú

黨

D d

I  㦨҈맔҈㦨҈├␔鼀

ᨨᆠ�泐ᨨ �� � ᆠ盐盐鼀 c = ᨨᆠ�泐ᨨ �� � 鼀 �盐鼀 v =

  ᆠ��  m㦨

҈ Ҙ e  ҈

Ҙe

c ҈⏌ Ҙe Ҙe = = v ҈⏌ Ҙe Ҙe

WWW.JEEBOOKS.IN

P-287

Ray Optics and Optical Instruments ҈

ᨨ ᆠ�ᨨ APB

ᨨ  ᆠ盐盐 ᨨn㦨҈�Dn㦨҈ f 㦨ᆠ鼀  ⼄ �㡰

Ҙ Ҙ Ҙ - Ҙ - + ҈= ҈ u v R - ҈ ҈ -  + =  Þ v㦨ᆠ鼀 -҈� v -҈

Þ ҈҈

҈ - Df =Þ Df = - ᆠ鼀   ҈� - ҈㡰 ҈�

 ᨨ �鼀�ᨨ O犨� ᨨ鼀 ᆠ鼀ᨨ �� ᨨ P T盐錐

I=

n n n  n҈  ҈+  = 

p P ҈ = ᨨ I µ A prl r

u

T盐錐

҈

  = = ᆠ鼀 ҈� ҈� - ҈   - ҈ + = ᔴ矄㜠ᔼᔼ 盐  ҈� ҈ ҈ - ҈� \ + = \㦨ᆠ鼀 - -  - ҈� ҈ ҈ - ҈� + = ᔴ矄㜠ᔼᔼᔼ \  - -  ҈ ҈ ҈ \ =\㦨҈黨�ᆠ鼀   - ҈  R = n - ҈㡰 Þ f = bᆠ㡰 f R  n - ҈㡰 ҈ n - ҈㡰 n + Dn - ҈㡰  n - ҈㡰 + Dn = + = f +Df R R R R \  f +Df =  n - ҈㡰 + Dn f +Df R [  n - ҈㡰 ] \ = ´ f  n - ҈㡰 + Dn R n  ҈㡰 [ ] = [  n - ҈㡰 + Dn] \

D f n -  - n +  - Dn = f [  n - ҈㡰 + Dn] -Dn -Dn =  = n -  + Dn  n - ҈㡰

Df Dn > f n

v R ҈ ҈� ҈� ҈  + =  d  �㡰 µ ҈ ҈ ҈ Þd�㦨\d㦨䰘ᆠ鼀 = d - � 

bᆠ㡰 㡰 꾀泐� � 和 矄 犨   n҈矄� �㦨n矄� r Þ n҈矄�  㦨n矄� q

 ҈ =

ᨨ鼀⼄盐�ᨨ  �㡰�  꾀矄ᨨ

\ ҈

  b 㡰꾀矄犨├ ᨨ犨m㦨    ᔴ矄㜠ᔼ

҈� ҈ ҈ - ҈� n҈ n n  n҈ + = + = Þ � V ҈ u v R

Þv㦨�ᆠ鼀 꾀��  ᨨ ᆠ�ᨨ � 和

�矄�矄 盐ᨨ鼀ᨨ矄 �ᆠ ᆠ�ᨨ  �� ᆠᨨ鼀� � ᨨ鼀矄盐

 矄 ᨨ犨 矄   ᨨ鼀꾀矄 犨 �ᨨ ��  �    鼀ᨨ矄   矄�泐 泐 ᆠ矄矄  ᨨ 矄盐  矄 ��  ҈

D f 㦨ᆠ鼀 ᨨ ᆠ�ᨨ � 和҈ 

ᔼ  矄�泐ᨨ � 矄ᨨ盐ᆠᨨ ᨨ犨 P㡰  �矄 ᆠ r ᨨ鼀   矄ᨨ盐ᆠ

҈

ᨨ b㡰

Þ

矄� ° =  矄� q Þ q 㦨 㦨r

ᔼ  ⼄盐 � ᔴ턼 졠  

 㦨q ҈� � � 

턼 �

䰘� 

a㝐





 졔 黨 졔 㡰졔҈� 졔Ð턼ᔴ㦨 Þ Ð턼ᔴ = �° Þ � 㦨�

ᆠ��ᆠ � ᨨ�矄鼀㜠��ᨨ 鼀 � C㦨 矄�

-҈ æ

҈ ö çè ÷ø 犨 �ᆠ �矄矄矄  �  

 ᨨᨨ�   ᆠ�ᨨ ├矄ᆠ ᆠᔴ ᔼ D턼㝐Ð턼㝐㦨҈  � 졔䰘� 㡰㦨

 ᨨ  �ᨨ � ᆠ�  ᆠᨨ 泐턼㝐ᨨ 꾀�矄 

�矄  � �矄 矄矄     ᆠ��ᆠ  �  ᆠ   泐 鼀�矄ᨨ盐ᨨ  ᆠ꾀 ᆠ㡰 ᨨ鼀  ��盐 �犨  � ᆠ�  泐졠   鼀� 泐㝐 �矄黨  㡰 泐 ��鼀�矄矄 ᨨ犨 �  ��盐  ᨨ �鼀� 犨� 犨 C O␔   鼀�ᨨ�矄 � 犨� 犨 㡰

҈䰘

 �㡰 ᲼Q Dn n҈㡰桌

ᨨ鼀P 犨� 矄矄 ᨨ盐� C

C

C



Dn Df <   

>  n f

�ᨨ  犨 







ᔼ鼀� P

҈

Df Dn     鼀� 矄 盐 ᆠ  �  � f n

O

O

ᆠ㡰 �鼀�I҈ᨨ 泐矄 ᨨ鼀 泐 矄L҈犨�ᆠ矄 �盐ᨨᆠ ᨨ矄ᆠᨨ  矄L

ᆠᨨ  矄盐 ᆠᆠ 泐ᆠᨨ ᆠ矄盐 ᆠᨨ  矄鼀 �盐矄

WWW.JEEBOOKS.IN

EBD_8341 P-288

Physics L

 �ᆠ├ 矄矄␔   泐 ᨨ鼀矄盐 ᆠACᨨ  �矄鼀 矄  �鼀 鼀盐� ᆠ�ᨨ 矄ᨨᆠᆠ盐�    �鼀

 �  矄�泐ᨨ  鼀�  泐犨�  鼀 �鼀盐鼀 �   矄鼀� 犨矄 盐 �ᨨ ᆠᨨ 矄盐ᆠ� �   ᆠ \ ᨨ鼀� �鼀盐鼀 �ᆠ├ 矄矄Dx㦨l Þ D x㦨mt㦨l 犨 t㦨 �ᆠ├ 矄矄ᨨ  �鼀㡰



O

I



\ d





꾀泐� �  矄 ᨨ鼀盐 ᨨ  矄 L

Þ \

f  f҈ - d 㡰 ҈ ҈ ҈ =  Þ v = f v f҈ - d f   + f҈ - d

ᨨ� ᨨ  �矄 ᆠᨨ  �鼀�I ᨨ鼀O

x=d+

f  f҈ - d 㡰 f f + d f҈ - d 㡰 = ҈  f  + f҈ - d  f҈ + f  - d

t㦨

l = ҈� 鼀 Ҙ

㡰 ᆠ盐矄S�矄ᨨ� 矄ᨨ盐ᆠ矄ᨨ�   ᆠ � �矄犨� ᆠ�ᆠ盐 㡰 ᔼ �  矄�泐ᨨ ��  � �ᨨ P �ᆠ泐 ᨨ鼀S I҈㦨I 

 �  矄�泐ᨨ ��  � �P  ᆠ�ᨨ  ᨨ鼀 鼀�ᨨ ABI㦨奠ᨨ I㦨 I 

 I 鼀� æ I -  I ö ҈ æ  ö =ç ÷ø = ÷ = çè ҈ ҈ I 鼀 è I +  I ø

ᨨ �  y㜠ᆠᨨᨨ � 犨盐矄鼀� � �ᆠ�ᨨ  ᨨ鼀盐 ᨨ 矄 L

ᆠ㡰 ᨨ鼀 �鼀盐鼀�  矄�泐 P  �  ᆠ㦨 nl ᔼ AB�矄 矄 �  泐 �矄 ᆠ x�犨�ᆠ盐矄   ��ᨨ  �  ᆠᨨ x

f  f҈ - d 㡰 v f + f -d f = m=  = ҈  u f҈ - d f҈ + f  - d



h D ´ f 꾀矄ᨨ m =  Þ h = D f҈ + f  - d \

҈黨

Df  D f҈ - d 㡰 f҈ + f  - d 㦨 f҈ + f  - d







ᆠ㡰 n҈㦨 ᆠ��  ᨨ � n㦨 ᆠ��  ᨨ 鼀鼀�犨 �ᆠ �矄 ��

ᨨ鼀� �鼀盐鼀盐ᨨ xn㦨҈

矄� q҈ n ᨨ鼀和 Ἐ矄犨  =

\

Q 



y㜠ᆠᨨᨨ � y 㦨Dh

= D-

和ᆠ

矄� q 



n ��\ q�矄矄ᨨ ��  ᆠ�  ᆠ㡰�矄ᆠᨨᆠ

C b㡰 和 ᨨ �� � 鼀 �盐鼀V㦨 n



x㦨lÞ x㦨



l  = =  鼀  

�㡰 ෌� D҈㦨鼀D㦨҈ᆠ鼀y҈㦨ᆠ鼀 O�矄 鼀� ᨨ�  ᨨ 犨ᨨ矄�矄 S҈ S S҈S㦨d㦨鼀鼀

n ᨨ鼀㜠鼀�㦨n

\ ҈

㡰

A

C 和 ᨨ �� �  鼀㜠鼀�V㦨  n 꾀泐� �和 Ἐ矄 犨  矄盐 ᆠ AB m҈矄� �㦨m矄� r

Þ

Ҙ�矄�  㦨Ҙp矄� r҈ Þ

Q \

r҈졔r㦨A r㦨A r҈㦨

S1 P

 =  矄� r҈ Þ r҈㦨 

ᆠ鼀

ᨨ

\ Q

N' M

Q

S2 S

 a =

A

ᨨ

a



y

O q

B 鼀 D҈

盐 ÐQMN㦨  Þ ÐAMQ㦨

C R

D ҈ᆠ鼀 D

y҈  ҈ = = D҈  �

矄� a㦨

҈ 

=

҈ ҈ » »  a �҈ ҈�

  �  ᆠDX҈㦨SS҈SS

ᨨ ᨨ

ᨨ

N

æ ҈ö DX҈ = d 矄� a = (  鼀鼀 ) ç ÷ 㦨҈鼀鼀 �㡰 è �ø

 R  ᨨ矄   ᨨ矄��ᨨ  ᨨ  ᆠ  ��  � �   �  ᆠ㦨 B

C

 ᨨ  ᆠ 泐� 矄�  �矄鼀 �矄 ᨨ  ᆠ 黨   ᆠ �ᨨ 鼀� ᆠe㦨 㡰 㝐盐�  ᆠ�ᨨ 矄 ᨨᆠᆠ盐 �    �鼀 ᨨ 鼀� �鼀盐鼀

ᨨ犨 DX  = S R - S҈R ᨨ DX  = d 矄� q ᨨᆠ ��  � �

 ��㡰

DX  - DX҈ =  ᨨ d 矄� q - DX҈ = 

WWW.JEEBOOKS.IN

P-289

Ray Optics and Optical Instruments ᨨ

d 矄� q = DX ҈ = ҈ 鼀鼀

ᨨ

㡰矄� q㦨҈ ᨨ 矄� q =

\

 q =

ᨨ

҈ y = � D

҈

犨 k㦨҈ 鼀㡰⏌  ᆠ��  ᨨ ��矄҈

泐矄 ᨨ鼀�ᨨ  矄鼀 �盐鼀ᔼᆠᨨ � 盐ᨨ盐矄泐 矄 ᨨ犨 矄 ᨨ鼀 和ᨨB�矄 q꾀 �ᨨ � ᆠ�  ᆠ㦨�B

҈ ҈ =  �

\

҈ ҈ » = 矄� q \  q = y  黨 � D D ҈ ᨨ y = = =  ᆠ鼀 � �

=

ᨨ

\ ᨨ矄��ᨨ  ᨨ ᆠ ��  � ��矄 ᆠ鼀ᨨᨨ� Qᨨ

矄�  CD ��㡰

A

ᨨ

㡰 쟼⼄盐�ᨨ  ᨨᆠᨨ泐y x㡰ᨨ 泐� 鼀 �盐鼀 꾀泐� � 和 Ἐ矄犨  ᨨ� 矄 A   B mA矄� �A㡰㦨mB矄� �B㡰 mA㦨҈ ᨨ鼀 �㡰ᆠ盐矄y㦨 �A㦨黨 ᆠ盐矄ᨨ � � �� ᆠ�  ᆠ �B㦨� mB㦨᲼ky⏌졔҈桌 犨  k㦨҈鼀⏌ ᨨ mB㦨᲼y⏌졔҈桌 ᨨ鼀 ���㡰  �㡰犨� ҈㡰 ҈㡰㦨᲼y⏌졔҈桌矄� �B㡰

C

S҈ P



S

S B



Q

D t ҈鼀鼀

矄� �㦨

ᨨ ᨨ

ᆠᨨ�㦨 y ᆠᨨ�㦨y⏌

㡰    �  ᆠ 犨    犨ᨨ 泐矄 泐㜠҈  ᆠ ᨨ鼀 盐矄盐 ᆠAB 泐㜠 ᆠ  ᨨ鼀ᨨ犨矄盐 ᆠ CD

ᨨ

dy 㦨y⏌ ᨨ y⏌dy㦨dx dx

l D x㦨amm맔t졔  l   �矄    

ᨨ

ᨨ

m҈㦨҈ ᨨ m㦨҈҈

҈

A t

amm맔t졔

B am

C

�  ᆠ矄 泐҈矄盐   ᆠ�ᨨ  ᨨ鼀   矄 鼀 �盐鼀ᨨ 矄盐 ᆠAB ᨨ ᆠᨨ 矄盐ᆠ� �   ᆠ   �  ᆠ㦨nl犨 n�矄҈

\

 m㦨҈

D



 mm

=

y⏌

x

dy = ò dx ᨨ y҈⏌㦨xÞ y㦨 x⏌㡰 

q

M



q q

d l

q=�

Q

N r �

d

ᨨ鼀 ��   矄矄�ᨨ ᨨ

 = 黨 鼀  ´ ҈

b

㡰 㡰 꾀泐ᨨ ��  � � �  � �矄 � ᆠ�   � � �  � � ᆠ�    � @ 黨 㡰 ᨨ  矄  ᨨ� ᨨ  � ᆠ�  ᆠ�矄   ᨨ��� A 㡰 y P x҈ y҈㡰 꾀�

B x y㡰

� q A 㡰  ᆠ��  ᨨ 鼀 �盐鼀㦨m m y㡰㦨᲼ky⏌졔҈桌҈⏌



am 㦨҈� g

l ҈ö æ a 㦨nl Þ   m m t = ç n - ÷ l  è ø

t㦨҈鼀

�

l t㦨 a

⏌

\ 쟼⼄盐�ᨨ ᨨ ᆠᨨ泐ᨨ 泐� 鼀 �盐鼀�矄y㦨 x⏌㡰 㡰 ᨨ  ᔼ ᨨ ├ ᆠ q 矄 ᨨ盐   �    C ᨨ 矄鼀盐矄 ᨨ C  盐矄ᨨ  m矄 ᨨ盐  �� ᨨ� ᨨ  犨ᨨ 矄 盐ᨨ l矄 ᨨ盐 矄鼀

ᨨ矄盐ᨨ  �ᆠ├ 矄矄tn㦨҈ \

y

 �㡰

҈

y ⏌ + ҈㡰

y ⏌

ò

 ���㡰

y⏌ + ҈㡰

҈

ᨨ

 �⼄盐� ᨨ   ᆠ��   m �矄 ᨨ盐 � ᨨ   矄矄  ᆠ ��  � ��矄 ᨨ盐 Q�    �  ᆠ㦨 \ m҈㡰t㦨DX҈ ᨨ m҈㡰 ҈㡰㦨҈ 

dy 㦨 q 꾀ᆠᆠᨨ � �ᨨ�ᨨ鼀泐�졔q㦨黨 dx p æ dy ö q㦨 � \ 矄ᨨ ç ÷ 㦨 q  è dx ø æp ö dy dy 㦨 ç - � ÷ ᨨ 㦨ᆠᨨ�  ��㡰  dx dx è ø

㝐 �盐鼀 꾀�

Ҙ l㡰㦨҈졔  l

ᨨ�   ᆠ�ᨨ 犨���  泐l҈㦨处

 矄� q =   �� 㡰 Þ q = �҈°

҈ ҈ = = ҈� 矄� q  b

\

Ҙ㦨

\

Ҙ㦨҈졔

\ 㡰

b㦨맔҈҈鼀 꾀泐� �和 Ἐ矄犨  N ᨨ犨 �  l 㦨�处

 ´ ҈ -҈ 㡰 

= ҈�

矄� r  ´ ҈ -҈ 㦨҈ 犨 Ҙ㦨҈졔 矄� � � ´ ҈-҈ 㡰  矄� r Þ r㦨 Þ ҈㦨 

Ҙ㦨

x  �㡰

WWW.JEEBOOKS.IN

EBD_8341 P-290

Physics

ᨨ鼀  ��盐��矄ᆠ   ��ᨨ  d㦨r� 㦨 �҈ 㦨䰘 ᆠ㡰  �  矄��矄 ᨨ   矄鼀�  鼀矄  I   I 矄ᆠ�泐

 ᨨ   ᨨᆠ �矄 ᆠ u㦨OA¢㦨OAAA¢㦨҈҈㦨ᆠ鼀

 ᨨᆠA¢矄�盐ᨨᆠ ᨨᆠᨨ ᆠ鼀�ᨨ

҈ ҈ ҈ + = v u f  ´ �  uf = = ᆠ鼀 = 䰘ᆠ鼀 v= u - f  - � 

ᨨ犨 ᨨ鼀鼀�ᨨ ᨨ鼀盐

꾀 r �



r



 



 ᆠ  泐矄��  矄矄 ᨨ盐�   �矄矄矄 矄盐 � � 盐 矄 � ᨨ ҈ᆠ鼀 �鼀�矄 ᨨ盐   ᨨ鼀 B�   矄 ᆠᨨ �矄矄矄盐 盐ᨨ�矄矄 ᆠ �鼀��矄 ᨨ鼀 BἘ



  �  ᆠDx㦨 m MB㡰 - AN 㦨

矄� r AB 矄� � 㡰 - AB 矄� q 㦨 矄� �

O

B

 矄 �  ᆠ犨 泐矄P Q�矄 ᨨ ᆠ鼀 �鼀盐鼀 �  矄�泐犨� ᨨ�   ᨨ鼀  � �   ᆠ \ 矄盐  ᔼ  矄�泐

I 鼀 = 䰘

(

I҈ + I 

) =( 

I + I

)





㦨  I 㡰 = 黨ᔼ

ᔼ  矄�泐ᨨ� IP㦨IA 졔 IB 졔 IC

IA =

ᔼ盐鼀� �ᨨ ᨨ犨㡰 ´ ᆠᨨ矄 q

pr  黨 ´ ᆠᨨ矄 ° ҈  =   =  p 犨 ⏌ 鼀 A 黨␔ p´ 

和�鼀�泐

IB =

҈ ´ ᆠᨨ矄 °  p ´ ҈�㡰 

黨

C ␔

A

졠 

P

B ҈␔



Ip =

黨C

泐矄 ᨨ��� � � ᨨ鼀 ᨨ�  ᨨᆠA矄盐 矄 ᆠ�ᨨ

盐ᨨ�矄矄矄 ᨨ矄�├� � ᆠᨨ ᆠ鼀�ᨨ ᨨ 鼀�ᨨ 泐矄ᆠᨨ鼀� � ᨨ鼀AἘ ᆠ鼀

҈ᆠ鼀

A

҈ᆠ鼀

æ è

D

꾀泐� � 和 Ἐ矄 犨  M

矄� 黨° Þ 矄� 黨° - C 㡰 ҈ ҈ 꾀矄ᨨ Ҙ =  矄� C

҈ Ҙ 

=

҈ ᆠᨨ矄 C

 �㡰  ��㡰

␔  C�矄 ᆠ��ᆠ �

\ A¢

҈m

M

ᨨ鼀 �㡰  ��㡰

O

m

q

҈ Ҙ= 

҈ ҈ + + ҈ = ҈黨␔ ⏌ 鼀  p p

꾀 矄 �  AA Ἐ = t ç҈ -

C �ᆠ 矄� 

C



IC㦨ᆠᨨ矄 㦨҈ \

 ᨨ�鼀� �矄 ᆠOB㦨OB 졔 BBἘ 㦨䰘졔҈㦨䰘䰘ᆠ鼀 ᨨ� � �� ᆠ�  泐BD ᨨ犨 �ᆠ  �»黨   �ᨨ  ᆠ�ᨨ  黨   C㡰 �矄 鼀 �鼀盐鼀 ᨨ  �矄 C �矄矄  C �矄 �   ᆠ��ᆠ �

B

҈ 犨 ⏌ 鼀  = p

B'

҈ Ҙ 

=

҈ ҈ = ÞC㦨� ᆠᨨ矄 C 矄� C

҈ =  = ҈҈ 矄� �°

 ᨨ 鼀� �鼀盐鼀盐ᨨ m�矄矄㦨҈҈ ᨨ犨 �ᆠ 矄 ᨨ  � ᨨ�矄� ᨨ鼀 泐ᨨ  �ᆠ ᆠ矄ᨨ   ᨨᆠ├

҈ö ҈ ö æ ÷ =  ç҈ ÷  㦨 ҈ ᆠ鼀 Ҙø ҈� è ø

WWW.JEEBOOKS.IN

PS-291

Wave Optics

Wave Optics

24

␔    �矄 鼀ᨨ ᨨ鼀L �矄鼀 �鼀犨��  �  ᆠ�矄� �鼀盐�ᨨ 犨 �  ᨨ  鼀 n㦨҈ ᨨ �矄鼀 �鼀㡰 Dx = nl = ҈l

Topic-1 : Wavefront, Interference of Light, Coherent and Incoherent Sources ҈

b㡰 ᨨ 꾀㡰

xP 

P

Q

xQ

A

d

xP - xQ = d + �㡰 - d - �㡰 = � 鼀  矄 �  ᆠDf 盐ᨨ  �  ᆠ

D = ct = c ´

p p p Dx 㡰 = �㡰 =  =   l 꾀 A, Q �矄    ᨨ  P 泐  矄 犨 鼀�  泐 Q ᆠ 矄  ᨨ犨鼀� 泐P p p \ ᨨ 矄 �  ᆠA - =    盐ᨨP� �  ᨨ Q泐黨 㡰

᲼ ᨨ鼀⼄盐�ᨨ  �㡰桌

c c = md  ��㡰 Q m = 㡰 v v

�矄 �矄 ᆠ�矄 ⼄盐  �矄 ᆠ� ᆠ盐盐鼀  �矄ᆠ ᨨ�ᆠ   졠�ᆠ   ᨨ �矄 泐 犨 �ᆠ  矄    L ҈  ᨨ盐�   鼀 �盐鼀ᨨ  ᆠ��  n҈㦨 n҈ L҈ 졠�ᆠ  ᨨ 矄ᆠᨨ  泐犨 �ᆠ  矄    L  ᨨ盐�  

I ᆠᨨ矄 㡰 =  I

鼀 �盐鼀ᨨ  ᆠ��  n = n L   �  ᆠ = n҈ L҈ - n L ᨨ犨  矄 �  ᆠ

  �  ᆠ xQ - xP = �鼀  矄 �  ᆠDf 盐ᨨ  �  ᆠ

=

d v

 = d

I A = I҈ + I  +  I҈ I  ᆠᨨ矄 Df  = I + I +  I ᨨ C

\  Dx = l = S҈ L Ἐ- S  L  Þ ҈ = d -  Þ d =  鼀 ᆠ㡰  �矄 ᆠ 矄  泐��  �   鼀 �盐鼀 ᨨ   ᆠ� �  鼀� �鼀t�矄�� 泐 d = vt  �㡰 犨 v�矄ᨨᆠ�泐ᨨ �� �  鼀 �盐鼀  �矄 ᆠ矄 泐�� � ᆠ盐盐鼀�  �矄�鼀

p p ´   �  ᆠ = ´ n҈L҈ - n L 㡰 l l 㡰 ᔴ泐 鼀�   ᨨ  �矄矄 �矄 ��� �   盐  ᨨ犨   ᆠᨨ �� � 矄ᨨ ᆠᨨᆠ 矄  ᨨ    鼀�  犨 ᨨ �矄矄矄 ᨨ犨 �   ��盐 =

p p p Dx 㡰 = �㡰 =   l



p p

ᨨ 矄 �  ᆠC = + = p  

和 ᨨ  鼀�  犨 ᨨ 

I  = I҈ + I  +  I҈ I  ᆠᨨ矄 Df㡰 ᔴᨨ �� �

 = I + I +  I

I ᆠᨨ矄 p) =  ᨨB,  �  ᆠ xP - xQ =   矄 �  ᆠ Df =

p 

I B = I + I +  I I ᆠᨨ矄

��� �

盐ᨨP� �  ᨨ Q泐黨 㡰

p = I 

 ᨨ�  矄��矄ᨨ  ��ᨨ A, B C犨��  �ᨨ 

ᔴᨨ �� �

I A  I B  IC =  I   I   =  ҈  㡰 ᔼ ��泐 S L =  鼀

�

ᆠ㡰 ෌�  鼀�盐  �ᨨᨨ 犨矄 �矄

矄ᨨ



� æö S҈ L =  + ç ÷ = = � 鼀  èø

和 d

æ a ö +҈   ça ÷ æ  + ҈ö  æ ö = = 㦨 = ç ҈ ÷ = ç ç ÷ ÷ a è ø è  ҈ø  ҈ ç  ҈÷ çè a ÷ø ҈

l 

L'

N/c





  �  ᆠ Dx = S҈ L - S  L = � 鼀 㦨

/c N

ᔼ鼀 æ a 졔 a҈ ö  ᔼ 鼀� çè a  a҈ ÷ø

a҈  = a ҈

L



b㡰

꾀矄 犨 ├ ᨨ犨

ᔼ鼀 æ 꾀҈ + 꾀  ö =ç ÷ ᔼ 鼀� è 꾀҈ - 꾀 ø



ᔼ҈ 꾀҈   ᔼ = 꾀  

和҈

WWW.JEEBOOKS.IN

EBD_8341 PS-292

Physics ᨨ 㡰 ᨨ�ᨨ

Dx㦨d矄� qÞdDx㦨dᆠᨨ矄dq

꾀 ᔼ 鼀 꾀 + 꾀  = ҈ Þ 鼀 =   Þ ҈ = ᔼ 鼀�

꾀҈ - 꾀  ҈ 꾀 鼀�

矄� �ᆠᨨ鼀ᨨ  ᨨ  ��  ᨨ

꾀҈ � ᔼ � æ�ö = Þ ҈ =ç ÷ = 꾀  ᔼ è  ø 黨 䰘

 黨

҈

 ␔ Ҙ� ᆠ矄矄  ᆠ矄矄

b㡰 ��  矄 盐犨 矄㡰  ᆠ ␔ ᆠ㡰 b㡰 ᔼ DOPM

O

R

⼄盐�㜠ᆠᨨ   矄ᨨ m҈㦨

��㡰

 ᨨ㜠ᆠᨨ ᆠ犨 矄ᨨ m㦨

C

d

\

 F㦨 R  O

q

I P

l l d ᆠᨨ矄 q d = CO + OP +  = + +  ᆠᨨ矄 q ᆠᨨ矄 q 

҈�ᆠ鼀 R҈㦨졔R

l l d ᆠᨨ矄 q + ҈㡰 +  = d ᆠᨨ矄 q + ᆠᨨ矄 q   ᨨᆠᨨ 矄盐ᆠ��   ᆠP  �  ᆠ㦨nl d ᆠᨨ矄 q +

҈

R㦨R

l  n - ҈㡰 l = nl Þ ᆠᨨ矄 q =   d

ᨨn㦨҈ ᆠᨨ矄 q =

҈

l d

꾀矄犨├ ᨨ犨I㦨I҈졔I +  I҈ I  ᆠᨨ矄 f ␔   矄 �  ᆠ�矄p⏌ Ip⏌㦨I졔I ÞIp⏌㦨�I 꾀�� 犨    矄 �  ᆠ�矄p b㡰

 ҈�㦨 R Þ R㦨҈ᆠ鼀  ᨨ犨m  ᆠ��  ᨨ  �⼄盐� 犨  矄 鼀�ᨨ �鼀�ᆠᨨ� ᆠ� 矄犨�  ᨨᆠ犨  ��矄ᆠ � ᆠ鼀\F¢㦨�ᆠ鼀 ᔼ  �矄ᆠ矄 \

\ Ip⏌Ip㦨�II㦨I 㡰 ᨨᆠ盐矄ᨨ ⼄盐  �  ᆠ� 矄盐

� �ᨨ  �矄 ᨨ    ᆠ泐�   ᆠ 矄��  �   ᆠ � �矄 犨�  ᨨ矄  ᆠ㡰 I҈㦨I I㦨I

҈ ö ҈ö ҈ æ҈ æ ҈ - ÷ ÷ø 졔 m҈㡰 çè 㦨 m҈҈㡰 çè ø R R ¥ R F¢ Þ

\ I 鼀 = I҈ + I  㡰 = I +  I 㡰  =  I 㡰 = 黨 I

bᆠ㡰

  �  ᆠ 泐ᨨ� ᨨ  ᆠ�ᆠ盐鼀  ᆠDx㦨d P҈ 矄� q d㦨҈鼀鼀 Dx㦨d 矄� q 꾀P҈ Dx㦨d矄� q Qq㦨 㡰 꾀P Dx㦨d矄� q Qq㦨黨 㡰

d矄� q S҈

҈ æ  ö  m - ҈㡰 㦨 çè - ҈÷ø ´  R R F¢

҈ ҈ ҈ m - ҈㡰  - m -m = ᨨ 㦨 㦨 \ m㦨҈ F¢ R R R � ҈ 꾀矄矄 ᨨ犨 �   ��盐 �   ᆠ犨�犨 �I㦨 I҈ ҈ I㦨I矄ᆠ  ᆠ矄�奠  矄鼀�矄䰘�奠ᨨ ��  ᔼ   ᆠ  ├矄ᆠ犨  泐矄꾀  Þ

  I 鼀� = I҈ - I  㡰  = I -  I 㡰 = I ҈

R = ¥

꾀ᆠᨨ   矄ᆠ ᨨ   鼀�ᨨ 矄�├ᆠᨨ ᆠ 鼀�ᨨ  �鼀� �矄 ᨨ鼀     ᨨᆠ �矄  �    ᨨᆠ �矄 ᆠ ᆠ ᨨ ᆠ盐盐ᨨ ᆠᨨ ᆠ鼀�ᨨ 꾀   ᆠ�ᨨ   ᨨ盐�   矄   泐矄 ᨨ      鼀�ᨨ

ᨨ鼀泐 ᆠ � ᨨ ᨨ鼀�鼀� ᨨᆠ�矄  \ ᨨᆠ � ᨨ 矄泐矄鼀 F㡰㦨҈�ᆠ鼀

I p = I + I +  I  I ᆠᨨ矄 p 㦨 I

҈҈

R҈ 㦨R



=

\

 㦨҈  ҈ö æ ҈ - ÷ 졔 m҈㡰 çè -R ¥ø

 æ  ö  æ  ö æ -҈ö ҈ ҈ = 㦨 çè - ҈÷ø + çè - ҈÷ø çè ÷ø 㦨 R R   R R R

q q

d ᆠᨨ矄 q OC = ᆠᨨ矄 q   �  ᆠ犨

 犨ᨨ泐矄ᆠ � �P

 㦨҈� 

�㡰

҈ ҈ ҈ ҈ ö æ҈ = + ç ÷ F f҈ f  㦨 m҈҈㡰 è R - R ø

M

Q

d ᆠᨨ矄 q ᔼ DCOP OP =

҈ Rl q\Rdqµ d ᆠᨨ矄 q ᆠᨨ矄 q 꾀矄犨鼀ᨨ ᨨ鼀P҈ᨨPq� ᆠ矄矄ᆠᨨ矄q ᆠ矄矄 ␔     矄ᆠ 犨     矄     鼀�ᨨ �矄 �  犨� 犨  矄泐矄鼀 ᨨ  犨ᨨ  矄矄

R㦨dᆠᨨ矄qRdqÞRdq㦨



q

S

P

d

Dx ҈ 鼀鼀 = 盐鼀ᨨ 鼀 �鼀n㦨 㦨 l  鼀 꾀P Dx㦨l ᲼\� � � �桌 꾀P 鼀 �鼀�矄 ᨨ鼀 

҈�

I 鼀 = I 鼀�

( (

)  I )

I҈ + I  I҈ -



෌矄矄 

෌矄矄 



䰘�I

�I



᲼ � I + ҈ I 桌

黨 =  㦨  ҈ ᲼ � I - ҈ I 桌

҈䰘�I ҈I



WWW.JEEBOOKS.IN

PS-293

Wave Optics

Topic-2 : Young's Double Slit Experiment ҈

l � ´ ҈-黨 = = ҈  㦨�䰘  d � ´ ҈- 㡰   �  ᆠ DP = d 矄� q = d q



d㦨 �矄 ᆠ犨 矄�矄㦨҈鼀鼀㦨҈鼀鼀 D㦨 �矄 ᆠ犨  矄�矄 矄ᆠ 㦨҈ᆠ鼀㦨҈鼀 y 㦨 �矄 ᆠ 犨  ᆠ  ��  � �   ᨨ矄  � � 㦨҈䰘鼀鼀

\ DP = 



҈

ᨨ��  � �  �  ᆠ鼀盐矄� �鼀盐�ᨨ l \�㦨 l1 =鼀l2 \l1 =� ᨨ 㦨㡰 l2 = 500 ᨨ鼀㦨�㡰 㡰  ҈㦨   㦨 � ᨨ �矄 鼀� �鼀 D =

҈҈

㡰 n҈ � �矄�矄�犨� �� ᨨ 犨 � l҈ n 犨� �� ᨨ 犨 � l 

Þ

n l҈ 䰘 = Þ n = ´ ҈ =  n҈ l   

㡰

෌�   �  ᆠ Dx =

\



䰘



҈

㦨

 ´ ҈ - � ´ ҈

=

p ҈+ ҈  = �  =  

҈ + ᆠᨨ矄

-黨

´

� 

)

҈ =  

ᆠ㡰

  �  ᆠDx㦨d矄� a졔d矄� q㦨da졔

yd 

᲼犨  a q矄鼀桌

l 

ᔼ æ pö  æ pö ᔼ = ᔼ ᆠᨨ矄  ç ÷ ᨨ = ᆠᨨ矄 ç ÷ è ø è ø ᔼ

(

l

 ᆠᨨ ᨨᨨ 鼀 �鼀矄ᨨ矄 �  �盐 � £ q £  㦨졔҈졔㦨҈

nlD ö æ çèQ b = ÷ d ø

æpö I I æpö ç  ÷ Þ = ᆠᨨ矄 ç ÷ = ᆠᨨ矄  ç ÷  Þ I = �  I èø èø ᆠ㡰 ෌�  �矄 ᆠ犨  矄ᆠ   矄�矄 D㦨҈�鼀 和�ᨨ 犨  矄�矄 㦨҈� 鼀鼀 ␔ � ᨨ 矄ᨨ盐ᆠᨨ �� l㦨�黨 鼀 � �㜠犨�   D ҈� ´ �黨 ´ ҈黨 m w= l = d ҈� ´ ҈  㦨�黨맔҈鼀鼀㦨�黨鼀鼀»�黨鼀鼀 ᆠ㡰 ෌� D㦨b l D m ҈㡰t Dl = ᨨ \ t㦨 m - ҈㡰 d d ᨨ 盐矄㡰和 � 㦨 b �� 㡰 D m - ҈㡰  ù m - ҈㡰t n lD é = \ D  êQ 和 � 㦨 úû a ë a a nl ᨨ t = m - ҈㡰 l b㡰 ෌�   �  ᆠ D =   矄 �  ᆠ Df㡰�矄�� 泐 p ( p) l = p Df = D 㡰  Df = l l   ᨨ 犨ᨨ 矄ᨨ盐ᆠ矄 �  �    矄矄

l  Þ =  

㡰 ᨨἘ Ἐ 盐鼀ᨨ 鼀 �鼀矄 矄� q㦨 l ´҈矄�  㦨 ´�´҈黨

Y P



p p l p Dx  = ´ =  矄 �  ᆠ矄Df = l l   æ Df ö I = I  ᆠᨨ矄  ç ÷ è  ø

�

l 

\D 㦨  ҈㦨 �   =

dy ҈- ´ ҈䰘 鼀鼀 = = ҈䰘 m鼀 D ҈鼀

n Dl n Dl b= ҈ ҈ =   d d

҈ 鼀鼀㦨� 鼀 

㡰

b㡰 ෌� ␔ � ᨨ �� l㦨� 鼀 �矄 ᆠ犨  矄�矄d㦨�鼀鼀 꾀 �盐犨�  ᨨ   � � ᨨ鼀 

q=

  �  ᆠ㦨 矄� q » q 㦨҈맔

黨

d s�n

a

aq d S

㡰 㦨

y O

q �n ds D

ᨨa㦨  �  ᆠDx㦨

yd 

 ´҈҈ 㦨맔҈鼀鼀 ҈

Dx  ´ ҈ - ҈҈ = 㦨 l  ´ ҈-  ҈҈ l \ Dx㦨 l Þ Dx㦨 n҈㡰   ᨨ犨

 ᆠ�   ᆠP�矄 矄盐ᆠ� 㡰

� �犨�  b㦨

ᆠ㡰

ᨨa㦨

l �矄�   ᨨ µ d

 � ᨨ� 㡰 p

é  ҈҈´ ҈ yù é Dx㦨 d ê a + ú 㦨맔҈ ê ҈ + ҈ êë Dû ë

- ù

ú 鼀㦨黨 鼀 úû

Dx 黨 ҈ = l 㦨 l    ᆠ 矄盐ᆠ��   ᆠ  㡰 ᨨa㦨 �  ᨨ� 졠㡰 p  Dx㦨da㦨맔҈맔 ҈ 㦨맔҈黨鼀㦨 鼀 Dx ᨨ犨 㦨҈ Þ Dx㦨҈l l  ᆠᆠᨨ 矄盐ᆠ��   ᆠ졠 ᨨ犨

WWW.JEEBOOKS.IN

EBD_8341 PS-294

҈

Physics

㡰 ᨨᆠᨨ鼀鼀ᨨ 鼀 �鼀n҈l҈㦨nl

n҈ l  � ´ ҈ -黨  = = = n l҈ � ´ ҈-黨 �

Þ

ᨨ鼀� �鼀盐鼀tn㦨҈錐\t㦨

ᨨl҈

y= y㦨 ҈

n҈l҈D  l҈㦨� 鼀 d  ´ � ´ ҈ -黨 ´ ҈�

� ´ ҈ - 

盐 Df =

p Dx l

ᨨ

y㦨䰘鼀鼀  Df = 矄ᨨ Dx =

p 



l 

ᆠ㡰 㡰 ᆠ㡰

ᔼ犨�ᆠᨨ ᆠ �ᆠᆠ�ᆠ矄

҈

b㡰

ᔼ  矄�泐 ᔼ 㦨 ᔼᨨ ᆠᨨ矄 

�

ᔼ ᔼ f p  ᔼ = ᨨ \ ᨨ = ᔼᨨ ᆠᨨ矄  \ f = n + ҈㡰     p  � f =  p p \    꾀   �  ᆠ æ lö l   n + ҈㡰 l Dx㦨 çè ÷ø f \ Dx㦨  l p    㡰

␔├ ᨨ犨  � �犨�   b =



Q ᆠ㡰

lR>l෌>lB \ b R>b G>b B ᔼ㦨ᔼ鼀 ᆠᨨ矄

 㦨 ᔼ 鼀 ᆠᨨ矄

p 矄� q l

p d 矄� q 㦨 l

҈

Ds㦨 

㡰

d⏌ d⏌

d p =   ᨨq㦨黨

\

\

æ p ö d=ç ÷ ҈�㡰 ҈㡰 = p ᨨ è  ø

q q �

ᔼ 鼀 æ p 矄� q ö = ᔼ鼀 ᆠᨨ矄  ç ÷  è l ø p 矄� q p p 矄� q ҈ æ l ö = Þ = \ q = 矄� -҈ ç ÷ ᨨ ᆠᨨ矄   l l è  ø 㡰 꾀 ᨨ ᨨ ├ 矄矄鼀� �鼀犨�ᨨᆠᆠ盐 ᨨᨨ   犨 � 矄� ᆠ�  矄�鼀盐 ᨨ盐矄泐  ᨨ鼀泐 n + ҈㡰 m + ҈㡰 l҈ = l   Þ n졔҈㡰l҈㦨 m졔҈㡰l \   n + ҈㡰 � 䰘 = = ᨨ҈n㦨҈m졔 ᨨ m + ҈㡰  � 泐� 矄ᆠ�ᨨ  ᨨm㦨n㦨  ᨨm㦨䰘n㦨҈  �矄 ᆠ 犨  鼀 犨�  �矄 ᆠ犨 矄盐ᆠ  ᨨ� 矄 Dl҈ ì  n + ҈㡰 - n҈ + ҈㡰 ü � Ds = í ý  d î þ 盐 n㦨҈n҈㦨 Þ

æ pd 矄� q ö I q㡰 = I  ᆠᨨ矄  ç ÷ è l ø y

S҈ q D S

æ p ö æ҈ö p d=ç ÷ ҈�㡰 ç ÷ = è  ø èø 

A

d矄

I鼀 µ a졔 a 㡰㦨 �a㡰

v  ´ ҈ l= = =  m ҈ h  d㦨҈�鼀 ᨨ q㦨



B

a

I鼀� µ a a㡰㦨 㦨҈䰘a㡰 ᔴ泐 �  矄��矄ᨨ ᨨ  鼀 �鼀 鼀� �鼀� ᆠ矄 ᆠ㡰 ␔├ ᨨ犨  �  矄�泐ᨨ �� 

\

lD d

d

k=

d pd  q I q㡰 = I  ᆠᨨ矄  犨  d=  l

 犨   ᔼᨨ �矄  ├�  矄�泐 

҈黨

҈l҈ D k l  D = d d

҈ ´  = ҈   ᆠ  盐鼀ᨨ  � �矄ᨨ矄 �  矄鼀矄�鼀 ᨨ   矄ᆠ 㦨҈ 㡰 ␔  矄�矄ᨨ ⼄盐犨�   I鼀 µ a졔a㡰 㦨a㡰 I鼀� µ aa㡰 㦨㡰 ␔   ᨨ 矄�Ἐ矄犨�  �矄犨�ᆠ ᨨ ᨨ 

\

b 

҈� ҈ ҈䰘

� �犨�  w㦨

I҈ W҈ a  W a = = =   Þ  b = Þ   I  W b W b

lD dy l = b  ��㡰 =  �㡰 d D  㝐盐�泐� � ⼄盐�ᨨ  �㡰   ��㡰 犨 �

y=

b㡰 Þ

æ Df ö ÷ è  ø

I 㦨 I ᆠᨨ矄 ç

ᆠ㡰



nl l = 㦨l m - ҈㡰 ҈� - ҈㡰

ᨨq㦨 d㦨ᨨ \

ᔼ q㡰㦨ᔼ





 b =

䰘

㡰 \

æ pö I I q㡰 = I  ᆠᨨ矄  ç ÷ = ᨨ è ø  d p =  I q㡰 =   

d = 

lD l D㡰 lD = = b   b Ἐ = d d ⏌ d

 � �犨�   �矄⼄盐 盐  ᨨ鼀 �鼀    ᆠ㦨ml SAS҈A㦨ml S҈ x + d 

d x

O

A

d

҈ ´  ´ ҈ -黨 㡰 é ҈ - 䰘 ù ê ú 㦨鼀鼀 ҈ ´ ҈ - ë  û   �  ᆠ㦨 Ҙ҈㡰t 㦨nl錐

S

\

é n - ҈㡰 d  + x  + d  + x  ù  d  - x  㦨ml ëê ûú

WWW.JEEBOOKS.IN

PS-295

Wave Optics



\

n҈㡰 d  + x  㡰 㦨ml

\

æ ö   ç ҈÷ d + x 㦨ml \ è ø

d  + x  㦨ml

\ d졔x㦨黨ml \ x㦨黨mld  ᔴᨨ鼀� �  �矄 ⼄盐�ᨨ  犨�    ��  ⼄盐�ᨨ

x㦨pmld犨� p㦨黨 \ p㦨 黨㡰 ᔼ 泐ᨨ盐 �Ἐ矄 ᨨ盐矄� �鼀 �  矄�泐ᨨ� �矄�� 泐

I = I  ᆠᨨ矄 

꾀矄 �矄犨 ᨨ 盐鼀 ᆠᨨ ��ᨨ  ᨨ鼀� �鼀�矄矄�矄 � 

 ᨨ�졠犨� ├�鼀� �鼀�矄 ᨨ鼀 �졠 꾀矄ᨨ 矄   矄ᆠ  �矄  �ᆠ盐 ᨨ    ᆠᨨ � � �   矄�矄和҈和  ᨨ � �矄ᨨ�  犨�矄鼀�㜠ᆠ�ᆠ盐 ᨨ 泐ᨨ  ᨨ  矄ᆠ �矄�㡰

f 



bᆠ㡰 Q

´

犨 f㦨 矄 �  ᆠ

꾀 �盐矄�ᨨ  �

矄� �⼄盐�ᨨ  �㡰

æf ö æ p ö ᆠᨨ矄  ç ҈ ÷ ᆠᨨ矄  ç ÷ è ø è ø = æf ö æ pö ᆠᨨ矄  ç  ÷ ᆠᨨ矄  ç ÷ è ø è ø K ҈  K 黨 K Þ = = Þ I = = I    ҈  \ n = 黨 I҈ = I



Þ

Þ ҈�l҈㦨҈l Þ l㦨҈�l҈҈�l҈㦨҈�맔� 鼀 Þ l㦨䰘� 鼀 ᨨ ᆠᨨ   矄ᨨ盐ᆠ矄 ᨨᆠᨨ 矄盐ᆠ� �   ᆠ

鼀�盐  鼀� ᨨ� 㦨A졔A㦨A Imax µ (2A)2 Þ Imax㦨I㦨ᔼ҈  㦨 ᔼ  矄�泐  盐 ᨨ ᨨ  矄� ᨨ � ᆠᨨ   矄ᨨ盐ᆠ矄   �  矄�泐   盐 ᨨ鼀泐 ᨨ �   ᆠ㡰

 ᨨ ᨨ�  矄�泐I㦨I 졔I 㦨I  ��㡰 ᨨ鼀⼄矄 �㡰  ��㡰

l 㦨 犨� 㦨҈ 

d 矄



和ᆠ

l ù é êëQ = 矄� q úû

l < l 矄� q

鼀 b

맔㦨�맔

p 맔  �  ᆠ l ᨨ  �  ᆠl 矄 �  ᆠ f҈ = p 矄� � 矄 �  ᆠ f =



l>l҈\b >b ҈

l

盐鼀ᨨ  � �矄� �� 犨�  mµ

 �㡰

p l ᨨ  �  ᆠ   矄 �  ᆠ f  =  

␔├ ᨨ犨  � �犨�   b =



(

ᔼ҈ + ᔼ

)



 ᔼ鼀�  㦨

(

ᔼ҈ - ᔼ

)



ᔼ ��泐ᔼ҈㦨ᔼ ᔼ㦨ᔼ \ ᔼ鼀  㦨黨ᔼ ᔼ鼀�  㦨ᔼ ␔  ᔼ҈㦨ᔼ㦨ᔼ  ᔼ鼀  㦨ᔼ ᔼ鼀� 㦨 � ␔     �  矄��矄 ᆠᨨ鼀 ⼄盐 ᔼ鼀�   盐ᆠ矄 ᨨ ᨨ ᆠ㡰 ᨨ矄犨 � 矄犨�鼀�矄矄� � ᨨ犨 �ᆠ   �  ᆠ Dx㦨 n҈㡰 l⏌

lD  y = n - ҈㡰   d ld 㦨  n - ҈㡰 b  Q d㦨b D㦨d㡰 b ld = n - ҈㡰 Qy㦨b⏌㡰 \  b

P

WWW.JEEBOOKS.IN

EBD_8341 PS-296

Þ

䰘

Physics

l=

b 犨  n㦨҈ n - ҈㡰d

l=

b b   d d

I b 㡰 鼀 = I 鼀�

\

( (

 n҈㦨҈n㦨  �㦨� r㦨䁸 矄和 Ἐ矄犨B n҈矄� �㦨n矄� r \



矄� r㦨

҈ ´ 矄� �° 

=

҈  Þ r㦨 

\ 꾀 � 鼀  泐  �矄 矄盐 ᆠ 犨�   ᆠ  泐 BC �矄    ᆠ  ᆠ 泐Bᨨ ᨨ� ᨨ 

I҈ = I

B �

A҈ = 꾀鼀�盐  �ᨨ A 

黨

) =黨  ҈ I )

I҈ + I  I҈ -

I P㡰>I P҈㡰 I P㡰>I P҈㡰

I҈ = I

C

 O

A n҈ = ҈

=

n =

n㦨҈�҈





꾀㜠矄錐㜠⼄錐ᔴ㜠錐㜠矄 ᨨ  �  ᆠl⏌ 矄 �  ᆠ�矄p⏌ ᨨ  �  ᆠl⏌ 矄 �  ᆠ�矄p⏌

ᨨ犨 ᨨ  ᆠ�ᨨ   矄 �ᆠ矄盐 ᆠ

 S҈ P - S P =  \ d P㡰㦨

  �  ᆠ ᨨP҈ P犨� ᨨ ᨨ �  矄��矄 �矄鼀 �鼀盐鼀 ᔼ  矄�泐ᆠᨨ � 盐ᨨ盐矄泐 ᆠ矄矄 ᨨ鼀 P ᨨ犨 矄 P

Þ

\

I P 㡰 > I P҈ 㡰

㡰 꾀 P ҈   �  ᆠ �矄 ᨨ  ᆠ P҈ �矄  �� 矄 ᆠ  � � dP҈㦨

dP =



n n҈ n - n҈ - = Qu㦨¥㡰 v u R ҈�҈ ҈�҈ - ҈҈ = \ OP㦨�鼀  OP

㡰

 ᆠ 鼀 �鼀�矄ᨨ�   �矄 ᆠxᨨ犨졠

\

Dx҈㦨 S҈PSP㦨

æ mg

 Dx㦨 ç

è mm

l l  dP҈ =  dP =  ҈

xd D

ö - ҈÷ 졔 盐ᨨ�矄矄矄 㡰 ø

ᔴ㡰  d P 㡰 = -l ⏌ 錐 d P҈ 㡰 = -l ⏌  d P 㡰 = -l ⏌ 

    �  ᆠ �矄 ᨨ \ Dx҈㦨Dx

I P 㡰 = I҈ + I  +  I҈ I ᆠᨨ矄  p㡰

\

 = I҈ + I  -  I҈ I  = I  + I  -  I  = 

I P҈ 㡰 = I҈ + I  +  I҈ I  ᆠᨨ矄 -p ⏌ 㡰  = I҈ + I  = I  + I  =  I 

æ pö I P 㡰 = I҈ + I  +  I҈ I  ᆠᨨ矄 ç - ÷ è ø  = I҈ + I  +

\

I҈ I  = I  + I  + I = I 

I P 㡰 > I P҈ 㡰 >I P㡰

ö xd æ m g =ç - ҈÷ t D è mm ø

æ mg

\

 矄 �  ᆠ

è mm

=

(

)

 = I҈ + I  -  I҈ I  =  -  I  ᔴ泐I P҈㡰㦨

ö - ҈÷ t ø

QDx҈㦨㡰

ö p p æ m g Dx = - ҈÷ t ç l l è mm ø

 ´ ҈ æ ҈� ö - ҈÷ ҈ ´ ҈- 㡰 㦨 -䰘 çè  ⏌  ø  ´ ҈ f I \ 㦨ᆠᨨ矄 㡰㦨䰘�  I

Q

I㦨Iᆠᨨ矄

ᨨ

I 㦨

ᆠ㡰

ᨨ鼀 �鼀盐鼀 �  矄�y 졠

I P҈ 㡰 = I҈ + I  +  I҈ I  ᆠᨨ矄 -p㡰 I P 㡰 = I҈ + I  +  I҈ I  ᆠᨨ矄 [ -�p ⏌ ]

d⏌ S

ᨨ졠  �  ᆠ㦨 ç

æ -p ö I P 㡰 = I҈ + I  +  I҈ I  ᆠᨨ矄 ç è  ÷ø

I = 

O x P



㡰

f㦨

= I҈ + I  = I  + I  =  I 

S҈ d⏌

t æ mg ö D - ҈÷ t ´ Þ x 㦨ç d è mm ø - æ ҈� ö ҈ ´ ҈ 㡰 ҈�㡰 - ҈÷ ´ =ç 㦨맔҈鼀 è⏌ ø � ´ ҈ -

㡰  dP = l ⏌ 錐 dP҈ = -l ⏌ 錐 dP = -�l ⏌҈

 = I҈ + I  -  I҈ I  = I + I  -  I 

P

 I   æ mg

꾀��   �  ᆠ㦨 ç

è mm

ö - ҈÷ t ø

ᨨ鼀 �鼀  �  ᆠ㦨nl

WWW.JEEBOOKS.IN

PS-297

Wave Optics \

æ mg

ö - ҈÷ t ø

nl㦨 ç

è mm

P S҈ Na

- æ mg ö t æ ҈� ö ҈ ´ ҈ = ҈ ҈ ç ÷ Þ l㦨 ç ÷ n è mm ø n è  ⏌  ø

҈

҈ ´ ҈ 鼀 ҈ 㦨

鼀 n n



  �  ᆠ犨 泐҈ ᆠ � �P㦨NS҈졔S҈M

盐� �n㦨҈ᨨ �  犨 � �   �ᨨ  맔҈鼀ᨨ䰘맔҈鼀犨� l㦨�맔҈䰘鼀 맔҈䰘鼀 㡰 ᔼ  � ᆠ�  鼀 矄 ᨨ鼀泐   �  ᆠ Dx㡰 ᨨ鼀  泐 矄� � ᨨ鼀 S҈   S  ᆠ � �ᨨ� P Dx㦨SPS҈P㦨 d 矄� q

Dx㦨d矄� a졔d矄� q

S҈ Na

P

҈ y

d

Q S

q q

ᨨᆠ 鼀 �鼀  �  ᆠ矄 ᨨ盐  ᨨ \ Dx҈㦨ᨨDx㦨

l 犨  

\ \

d 矄� a㦨d 矄� q µ㦨q㦨

Q

y㦨

n㦨҈

d 矄� q 㦨 n҈㡰

l 

n - ҈㡰l n - ҈㡰� n - ҈ = = d  ´ ҈  꾀矄ᨨ -҈ £ 矄� q £ ҈ \ᨨ矄矄�盐矄ᨨ 鼀᠀҈ ±  ᨨ鼀DPOQ ᨨ矄��ᨨ  ᨨ 鼀� �鼀

D 矄� q 

҈ - 矄� q



矄� q ҈ - 矄�  q

҈ - 矄�  q

㦨 �鼀

d 矄� q =

\

矄� q =

\

y㦨

l 

l + d 矄� a 

� ҈ ҈  l + 矄� a = + 矄� ° = + = d  ´҈   

矄� q ҈ - 矄�  q

㦨҈҈鼀

Fᨨr f�rst m�n�ma ᨨn the ᨨther s�de

҈ ᨨm㦨졔҈ 矄� q =  y㦨   m㦨҈ 矄� q = -   y = -҈҈ 鼀   m㦨졔 矄� q = \y㦨졔҈҈鼀  ҈ m㦨 矄� q = - \y㦨鼀 

d 矄� q㦨

矄� q㦨 \

l ᨨ 

l � ҈ = ᨨ 矄� q㦨 d  ´ ҈ 

y㦨

矄� q ҈ - 矄�  q

㦨鼀

 ᆠ y㜠ᆠᨨᨨ � 矄 ᨨ    �矄 鼀� �鼀 ᨨ  �  矄�  ᨨ    ᆠ 鼀 �鼀盐鼀鼀 ҈҈鼀

㡰 ᔼ  � ᆠ�  鼀鼀├矄  �ᨨ  犨� x㜠 �矄   �  ᆠ犨 泐҈ ᆠ � � P㦨SMNS҈ Dx҈㦨 d 矄� q - d 矄� a

Þ

QD㦨҈鼀㡰

 ᨨ y㜠ᆠᨨᨨ � 矄ᨨ  �   ᆠ鼀� �鼀ᨨ   矄ᆠ  矄 ᨨᨨ犨矄

\

矄� q

Fᨨr f�rst m�n�ma錐 d 矄� q - d 矄� a =

矄� q =

y㦨D  q =

y

 O

M

꾀   �  ᆠ ᨨ鼀� �鼀盐鼀�  矄�泐㦨 n҈㡰

Þ

M

P

D 㦨҈鼀㡰

\

d q Qq a S



d矄 � q

҈

q d q aQ M S

-

㦨

y



 矄 �  ᆠf㦨

p p Dx = �l + D 㡰 l l

␔ Dl⏌

æ fö 

␔├ ᨨ犨 I f㡰㦨I鼀 ᆠᨨ矄 ç ÷ è ø

WWW.JEEBOOKS.IN

EBD_8341 PS-298

Physics

ᔼ  矄�泐 ᨨ  㦨 

 I  鼀

㦨҈졔맔҈졔 ҈ - ´  ´ ҈ - ᆠᨨ矄 �

f f p  I 鼀 = I 鼀 ᆠᨨ矄  Þ = ° =    



\

t 㦨黨맔҈ 鼀

�㡰

a mm

\



=

la  Þ lm㦨 lm

la

l D  ´ ҈ ´ ҈ D l 㦨 a = - a d ҈ ´ ҈ m Ҙd

yn =

Dt é g m ù - ҈ú 㦨 ê d ë mm û

 矄 �   矄 ᨨ  矄盐ᆠ     鼀� �鼀 矄 � 矄 ᨨ    �矄 �

b 

t m



҈

b⏌

㝐� �鼀





 ´ ҈

= ҈� ´ ҈ - 鼀

㡰 ෌�  ᔼ  矄�泐I 㦨␔鼀 꾀 A㦨맔҈鼀 꾀 �盐矄 w㦨҈ ⏌矄

҈   ᨨ盐�ᨨ

 㡰  ´ ҈- 㡰 \꾀� �泐 = ; � ´ ҈-   

㡰

Dt é g m - m m ù b ê ú= d ë mm û 

Þ 㦨 

 ´ � ´ ҈-҈ ´ ҈ ´ ҈-

Q < ᆠᨨ矄 q > =

㝐 �鼀

D



㦨҈҈䰘맔҈鼀

꾀� �泐 = I A < ᆠᨨ矄 q >

d

\

 ´ ҈-

Topic-3 : Diffraction, Polarisation of Light and Resolving Power



S

 ´ � ´ ҈-҈ ´ ҈ ´ ҈-

矄 �矄 ᆠ ᨨ鼀 ᆠ 鼀 �鼀盐鼀 盐矄ᆠᨨ矄ᨨ 矄ᨨ  ��  � �ᨨ l҈㦨�处ᨨ � ��  � �ᨨ l㦨�处 ᔼ矄 �矄 ᆠ ᨨ鼀 ᆠ 鼀 �鼀

㦨맔҈鼀 ��㡰 �t   �ᆠ├ 矄矄ᨨ �矄矄 ᆠ犨 �ᆠ ᆠᨨ矄ᨨ ᨨ  矄�矄 矄 � ᨨ  � �矄犨  ᨨ 矄��矄ᆠᨨ 犨�  �

�矄矄 矄 

矄 � � �ᨨ   � �矄㦨

y㦨

nl҈ D ml  D n �  = = = \ d d m � �

-҈

� �犨�  㦨

n lD  ᨨ ��  � �n㦨 d

��㡰   ��  � �ᨨ 犨 � �处ᆠᨨ� ᆠ� 犨� 鼀  ��  � � ᨨ 犨 �  �处 �矄 ᆠ 犨� 矄鼀 ᨨ鼀 ᆠ �� 

a mҘ

␔ � ᨨ �� �  �� �⼄盐� 㡰 \

 �㡰 꾀矄 犨 ├ ᨨ犨 �矄 ᆠ ᨨ     ��  � � ᨨ鼀   ᆠ 鼀 �鼀

yn =

l p p = �l + D 㡰  Þ Dx�l졔 㦨t   l

Þ

p 㦨䰘맔҈␔ 

b dm µ  ´ ҈- ´ ҈- ´ ҈ 㦨  g Ҙ - m µ㡰 ´ D  ҈� - ҈㡰 ´ ҈

㦨҈�䰘�맔҈䰘鼀㦨҈�䰘�맔҈鼀  ᨨ犨  矄鼀�  泐 A P҈㦨҈奠ᨨ I prA 㡰 㦨 ê҈奠 ᨨ ç

和鼀矄  �盐 矄�ᨨ  犨  犨ᨨ �矄  ᨨᆠ矄  鼀ᨨᨨ   

和�鼀�泐 ᨨ犨  矄鼀�  泐 B

q = ҈

é

æ ҈ ö ù ´ p ҈㡰  㦨҈␔ è p ÷ø úû

ë

é

æ ҈ ö ù ´ p ´ 㡰  㦨맔҈␔ è p ÷ø úû

 㦨 盐 �鼀 ᨨ  矄ᆠᨨ �矄 ᆠ졠҈졠㦨  q㡰d 㝐� �鼀盐鼀矄�ᨨ 犨 ᨨᆠ矄ᨨ   矄盐 ᆠᨨ 鼀ᨨᨨ 

P㦨 ê҈奠 ᨨ ç

ë

Df  矄 �  ᆠ� ᨨ 盐ᆠ 泐 �鼀 \ 㦨 \

Df 㦨

lö æ = ç ҈ ÷ d è aø

p    �  ᆠ� ᨨ 盐ᆠ 泐  �鼀㡰 l

p p p ҈ ´ Ҙ - ҈㡰 t = -҈ ᲼҈�҈桌맔맔҈ 㦨  l  ´ ҈ ᨨ犨ᆠ�  ᨨᆠ矄ᨨF

P 㦨P҈졔P졔 P҈ P ᆠᨨ矄 D f

l a

= 

҈㡰 �� ´ ҈ -҈ 㡰 ´  ´ ҈� ´ ҈ �

㦨�맔҈鼀㦨�鼀»鼀 b㡰 꾀ᆠᆠᨨ � � ᨨ⼄盐矄�ᨨ   �  矄�泐ᨨ ��  ᆠᨨ鼀� �ᨨ盐 ᨨ   泐矄�矄盐矄 ҈奠ᨨ   ᨨ��� �  矄�泐 I㡰 矄� �I㦨Iᆠᨨ矄q

WWW.JEEBOOKS.IN

PS-299

Wave Optics

I ҈ = I  ᆠᨨ矄 q Þ = ᆠᨨ矄  q ҈ ҈ ҈ Þ ᆠᨨ矄 q = = ҈ Þ q » 䰘҈° ҈

Þ

 ᨨ  � 泐犨 �ᆠ     泐矄  ᨨ ᨨ 盐  ᨨ  盐ᆠ    ᨨ盐盐 �  矄�泐 ᨨ  ᨨ f=黨 q 㦨黨 䰘҈ 㦨҈ 

�

l´ 錐 � �犨�   b = Ἐ 

҈- =

� ´ ҈- ҈ - ´ � ´҈ - ´ =  Ἐ ´ Ἐ

 ᨨ矄� 矄�ᨨ  �矄 ᆠ  㦨�m鼀 ᆠ㡰 꾀 �矄 ᨨ  矄鼀�矄矄�ᨨ  ᨨ 꾀

҈҈

ᨨ�矄꾀

҈l Ҙ矄� q

㡰 x㦨

㦨

ᨨ l =

҈ ´ � 㦨Ҙ鼀  ´ ҈�



æ I ö ᆠᨨ矄 ᆠᨨ矄  ÷ø

ᆠ㡰 I㦨 çè

꾀 � ᨨ 盐ᆠ� �ᨨ�矄ᔴ 犨 꾀 





I  ҈ ´ ´ 㦨   



҈l ҈ ´  ´ ҈-黨 = d � ´ ҈-

㦨맔҈䰘 䰘  黨

㡰 q =

b㡰 b㡰 꾀ᆠᆠᨨ � � ᨨ 犨矄矄 犨  ᆠ� �  ᨨ  鼀� m㡰�矄⼄盐ᨨ � ᨨ ᨨ�矄� � �

҈

҈

҈� ҈



Þ μ  졔 (҈�)  ( μ 맔҈�)



҈

 - ҈㡰 l l  ´ �� ´ ҈ -黨 = =    ´  ´ ҈ -䰘 p q ;  

㡰 ᨨ�矄꾀    矄鼀 �� 鼀  ᨨ   矄鼀�矄矄�ᨨ

 �矄 矄矄矄盐鼀ᨨ�矄ᆠ�矄� ᨨ 盐ᆠ q �

ᨨ 

ᆠᨨ矄  q =



æ ö çè ÷ø 

҈

c+ 錐 V 㦨 � 矄  ᨨ  ᨨᆠ c+

f㦨҈෌

 �鼀� �鼀盐鼀盐ᨨ m 矄 ᨨ盐 �

l 㡰 꾀 �盐犨�  ᨨ ᆠ 鼀 �鼀㦨

 Þ ᆠᨨ矄 q = 

㡰 矄 ��矄�ᆠ ᨨἘ矄  ᆠ 矄 ᨨᆠ�泐ᨨ  ᨨ矄 �矄

ᨨ矄鼀矄ᆠᨨ鼀 ᨨ�� 

f = f

 �

҈ ᨨ q = �° 

҈ ҈ ᆠᨨ矄  q ´ ᆠᨨ矄  q =  

ᨨ μ  졔 (҈� )