Title

: CBSE Class XII 2022 - Term II : Chapter and Topic-wise Solved Papers 2011-2020 & Question Bank : Physics

Language

: English

Editor’s Name : Amit Singh Copyright ©

: 2022 CLIP

No part of this book may be reproduced in a retrieval system or transmitted, in any form or by any means, electronics, mechanical, photocopying, recording, scanning and or without the written permission of the Author/Publisher. Typeset & Published by : Career Launcher Infrastructure (P) Ltd. A-45, Mohan Cooperative Industrial Area, Near Mohan Estate Metro Station, New Delhi - 110044 Marketed by : G.K. Publications (P) Ltd. Plot No. 9A, Sector-27A, Mathura Road, Faridabad, Haryana-121003 ISBN : 978-93-92837-42-5 Printer’s Details : For product information : Visit www.gkpublications.com or email to [email protected]

CONTENTS 1.1 - 1.11 Electromagnetic Waves 1.1 1.3 1.5 1.9 1.10

[Topic 1] Electromagnetic Waves, its Types & Properties Previous Years’ Examination Questions Topic 1 Solutions Multiple Choice Questions Solutions

2.12 - 2.35 Ray Optics and Optical Instruments 2.13 2.15 2.17 2.27 2.28 2.29 2.29 2.30 2.34 2.35

[Topic 1] Reflection, Refraction and Dispersion of Light Previous Years’ Examination Questions Topic 1 Solutions Multiple Choice Questions Solutions [Topic 2] Optical Instrument Previous Years’ Examination Questions Topic 2 Solutions Multiple Choice Questions Solutions

3.36 - 3.57 Wave Optics 3.37 3.37 3.38 3.40 3.41 3.41 3.42 3.43 3.49 3.50 3.50 3.51 3.52 3.56 3.57

[Topic 1] Huygens Principle Previous Years’ Examination Questions Topic 1 Solutions Multiple Choice Questions Solutions [Topic 2] Interference of Light Previous Years’ Examination Questions Topic 2 Solutions Multiple Choice Questions Solutions [Topic 3] Diffraction and Polarisation of Light Previous Years’ Examination Questions Topic 3 Solutions Multiple Choice Questions Solutions

4.58 - 4.72 Dual Nature of Radiation and Matter 4.58 4.59

[Topic 1] Photoelectric Effect Previous Years’ Examination Questions Topic 1

4.61

Solutions

4.67

Multiple Choice Questions

4.68

Solutions

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4.68

[Topic 2] Matter Wave

4.69

Previous Years’ Examination Questions Topic 2

4.69

Solutions

4.70

Multiple Choice Questions

4.71

Solutions

5.73 - 5.86 Atoms 5.73

[Topic 1] Rutherford’s Atomic Model, Bohr’s Model & Energy Level Diagram

5.75

Previous Years’ Examination Questions Topic 1

5.77

Solutions

5.84

Multiple Choice Questions

5.85

Solutions

6.87 - 6.97 Nuclei 6.87

[Topic 1] Radioactivity and Decay Law

6.89

Previous Years’ Examination Questions Topic 1

6.89

Solutions

6.92

Multiple Choice Questions

6.93

Solutions

6.93

[Topic 2] Mass Defect and Binding Energy

6.94

Previous Years’ Examination Questions Topic 2

6.95

Solutions

6.96

Multiple Choice Questions

6.97

Solutions

7.98 - 7.123 Semiconductor Electronics 7.99

[Topic 1] Semiconductor, Diode and Its Applications

7.100

Previous Years’ Examination Questions Topic 1

7.102

Solutions

7.109

Multiple Choice Questions

7.110

Solutions

7.111

[Topic 2] Transistors, Its Application and Logic Gates

7.113

Previous Years’ Examination Questions Topic 2

7.115

Solutions

7.122

Multiple Choice Questions

7.122

Solutions

1 - 28 Solved Paper Physics 2019 1 - 19 Solved Papers Physics 2020

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PREFACE Physics is a tricky subject. Your basic concepts of Physics need to be in place if you want to excel in Board Examination. At Career Launcher, our goal is not only to help you maximize your scores in Class XII Physics Board Exam, but also to lay a strong foundation in the subject to help you get ahead in your college and professional career. Over the last decade, we all have seen how the question paper pattern of Class XII Physics paper has kept changing. Bearing in mind this unpredictable nature of Class XII board papers, we've come up with Chapter-wise Solved Papers & Question Bank for Physics for Class XII Term II to help you prepare better and face the Boards with confidence. Exclusively designed for the students of CBSE Class XII by highly experienced teachers, the book provides solution to all actual questions of Physics Board Exams conducted from 2011 to 2020. The solutions have been prepared exactly in coherence with the latest marking pattern; after a careful evaluation of previous year trends of the questions asked in Class XII Boards and actual solutions provided by CBSE. The book follows a three-pronged approach to make your study more focused. The questions are arranged Chapter-wise so that you can begin your preparation with the areas that demand more attention. These are further segmented topic-wise and eventually the break-down is as per the marking pattern. This division will equip you with the ability to gauge which questions require more emphasis and answer accordingly. Apart from this, several value-based questions have also been included. At the end of the book, solved paper of 2020 Board exam has been provided for you to practice and become familiar with exam pattern. We hope the book provides the right exposure to Class XII students so that you not only ace your Boards but mold a better future for yourself. And as always, Career Launcher's school team is behind you with its experienced gurus to help your career take wings. Let's face the Boards with more confidence! Wishing you all the best, Team CL

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Blueprint & Marks Distribution Class 12th Physics Term II Analysis Unit Wise 2021-22 No. of Periods

Name of Units

Unit-5

Electromagnetic Waves

2

Unit-6

Optics

18

Unit-7

Dual Nature of Radiation and Matter

7

Unit-8

Atoms and Nuclei

11

Unit-9

Electronic Devices

7

7

45

35

Total

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Marks Distribution

Units

17 11

UNIT V: ELECTROMAGNETIC WAVES

2 Periods

Chapter-8: Electromagnetic Waves Electromagnetic waves, their characteristics, their Transverse nature (qualitative ideas only). Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays) including elementary facts about their uses.

UNIT VI: OPTICS

18 Periods

Chapter-9: Ray Optics and Optical Instruments Ray Optics: Reflection of light, spherical mirrors, mirror formula, refraction of light, total internal reflection and its applications, optical fibres, refraction at spherical surfaces, lenses, thin lens formula, lensmaker's formula, magnification, power of a lens, combination of thin lenses in contact, refraction and dispersion of light through a prism. Optical Instruments: Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers. Chapter-10: Wave Optics Wave Optics: Wave front and Huygen's principle, reflection and refraction of plane wave at a plane surface using wave fronts. Proof of laws of reflection and refraction using Huygen's principle. Interference, Young's double slit experiment and expression for fringe width, coherent sources and sustained interference of light, diffraction due to a single slit, width of central maximum.

UNIT VII: DUAL NATURE OF RADIATION AND MATTER

7 Periods

Chapter-11: Dual Nature of Radiation and Matter Dual nature of radiation, Photoelectric effect, Hertz and Lenard's observations; Einstein's photoelectric equation-particle nature of light. Experimental study of photoelectric effect Matter waves-wave nature of particles, de-Broglie relation

UNIT VIII:

ATOMS AND NUCLEI

11 Periods

Chapter-12: Atoms Alpha-particle scattering experiment; Rutherford's model of atom; Bohr model, energy levels, hydrogen spectrum.

(vii)

Chapter-13: Nuclei Composition and size of nucleus Nuclear force Mass-energy relation, mass defect, nuclear fission, nuclear fusion. Mass-energy relation, mass defect; binding energy per nucleon and its variation with mass number; nuclear fission, nuclear fusion.

UNIT IX: ELECTRONIC DEVICES

7 Periods

Chapter-14: Semiconductor Electronics: Materials, Devices and Simple Circuits Energy bands in conductors, semiconductors and insulators (qualitative ideas only) Semiconductor diode - I-V characteristics in forward and reverse bias, diode as a rectifier; Special purpose p-n junction diodes: LED, photodiode, solar cell.

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1

CHAPTER

Electromagnetic Waves Chapter Analysis with respect to Last 3 Years’ Board Exams List of Topics

2016 Delhi

Basic idea of displacement current, Electromagnetic waves, their characteristics, their transverse nature Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays) including elementary facts about their use

2017

All India

Delhi

1Q (3 marks)

1Q (1 mark)

2018

All India Delhi/All India 1Q (1 mark), 1Q (1 mark) 1Q (1 mark), 1Q (1 mark), 1Q (2mark)

1Q (1 mark)

On the basis of above analysis, it can be said that from exam point of view Characteristics and Nature of Electromagnetic Spectrum, Applications of Different Parts of Electromagnetic and Electromagnetic Wave are most important concepts of the chapter.

[Topic 1] Electromagnetic Waves, its Types & Properties Summary

Properties of EM Waves

Displacement Current • It is defined as the rate of change of electric displacement. d IH dt

• The electric and magnetic fields Ex and By are always perpendicular to each other, and also to the direction z of propagation. Ex and By are given by:

where H0 is the

E x = E 0 sin  kz-Z t

permittivity of the free space and Is is the amount of electric flux.

B y = B 0 sin  kz-Z t

• It is given by I d

H0

CHAPTER 1 : Electromagnetic Waves

1.2 x E

z

y

B

Where, “k” is the magnitude of the wave vector (or propagation vector) and can be calculated as; 2S

O

x Z is the angular frequency, • “k” is direction describes the direction of propagation of the wave. The speed of propagation of the wave is Z . k • The frequency of EM waves can be from 0 to i . Ampere Circuital Law is given by:

Õ B º dl

P0 i t

The four Maxwell’s equations are given as: Q • Gauss’s law of electricity:  Õ E .dA

H0

• Gauss’s law of magnetism: • Faraday’s law:

Õ E .dl

Õ B .dA

0

d IB dt

d IE dt An electric charge oscillating harmonically with a frequency, produces electromagnetic waves of the same frequency . The frequency of the electromagnetic wave naturally equals the frequency ofoscillation of the charge. An electric dipole is a basic source of electromagnetic waves. • Ampere-Maxwell law:

Õ B .dl

Properties of EM Waves

• Oscillations of electric and magnetic fields sustain in free space, or vacuum. So, the electromagnetic waves can travel in vacuum.

Fig. Electromagnetic Waves

k

From Maxwell’s equations it can be seen that the magnitude of the electric and the magnetic fields in E0 an electromagnetic wave are related as B 0 c

P0 I c  P0H 0

• An electromagnetic wave carries momentum and energy. Since an electromagnetic wave carries momentum, it also exerts pressure, called radiation pressure. • Let the total energy transferred to a surface in time t is U, so the magnitude of the total momentum of an electromagnetic wave delivered U to the surface (for complete absorption) is, P c • The energy of electromagnetic waves is shared equally by the electric and magnetic fields.

Types of EM Waves • Radio waves are produced by the accelerated motion of charges in conducting wires. They are used in radio and television communication systems.The radio waves generally lie in the frequency range from 500 kHz to about 1000 MHz • Microwaves have frequency in the range of gigahertz and are used in aircraft navigation. • Infrared waves are also referred to as heat waves as they are produced by hot bodies and molecules. • Visible rays can be detected by the human eye. They lie between frequency range of about 4 × 1014 Hz to about 7 × 1014 Hz or a wavelength range of about 700 –400 nm. • Ultraviolet radiation or the UV radiation is produced by special lamps and very hot bodies. • X-rays lie beyond the UV region and are used as a diagnostic tool in medicine and for treating various kinds of cancer.

• Gamma rays are emitted by radioactive nuclei and also are produced in nuclear reactions and are used in destroying the cancer cells. The properties of different types of EM Waves are: Type

Wavelength range Production

Detection

Radio

> 0.1 m

Rapid acceleration and decelerations of electrons in aerials

Receiver’s aerials

Microwave

0.1 m to 1 mm

Klystron valve or magnetron valve

Point contact diodes

Infra-red

1 mm to 700 nm

Vibration of atoms and molecules

Thermopiles, Bolometer, Infrared RJQVQITCRJKEſNO

Light

700 nm to 400 nm

Electrons in atoms emit light when they move from one energy level to a lower energy level

The eye, Photocells, Photographic ſNO

CHAPTER 1 : Electromagnetic Waves

1.3

Ultraviolet

400 nm to 1 nm

Inner shell electrons in atoms moving from one energy level to a lower level

2JQVQEGNNU2JQVQITCRJKEſNO

X-rays

1 nm to 10–3 nm

X-ray tubes or inner shell electrons

2JQVQITCRJKEſNO)GKIGTVWDGU Ionisation chamber

)COOC rays