Engineering Physics I : For Anna University

144 Pages·2011·3.789 MB·English

by  ITL Education Solutions Limited, S. Mani Naidu

A text book of
ENGINEERING PHYSICS-I
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A text book of
ENGINEERING
PHYSICS-I
ITL Education Solutions
Limited
Research and Development Wing
New Delhi
Dr S. Mani Naidu
M.Sc., Ph.D., P.G.D.C..A
Associate Professor of Physics
Sree Vidyanikethan Engineering College
Tirupati, Andhra Pradesh
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Copyright © 2012 Dorling Kindersley (India) Pvt. Ltd.
Licensees of Pearson Education in South Asia
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written consent.
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right to remove any material present in this eBook at any time.
ISBN 9788131766828
eISBN 9789332509702
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Registered Office: 11 Local Shopping Centre, Panchsheel Park, New Delhi 110 017, India
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Contents
Preface ix
Chapter 1 Ultrasonics 1-1
1.1 Introduction 1-1
1.2 Principle of ultrasonic testing 1-1
1.3 Ultrasonic flaw detector 1-2
1.4 Ultrasonic transducer 1-3
1.5 Couplant 1-6
1.6 Inspection methods—Pulse echo testing technique 1-7
1.7 Different types of scans 1-9
1.8 Inspection standards [Reference standards
or calibration blocks] 1-10
1.9 Applications of ultrasonics in NDT 1-13
Multiple-choice Questions 1-13
Answers 1-15
Review Questions 1-15
Chapter 2 Lasers 2-1
2.1 Introduction 2-1
2.2 Characteristics of laser radiation 2-1
2.3 Spontaneous and stimulated emission 2-2
2.4 Einstein’s coefficients 2-4
2.5 Population inversion 2-6
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vi Contents
2.6 Helium–Neon gas [He–Ne] laser 2-8
2.7 Ruby laser 2-10
2.8 Semiconductor lasers 2-12
2.9 Carbon dioxide laser 2-15
2.10 Applications of lasers 2-18
2.11 Holography 2-20
2.12 Basic principle of holography 2-21
2.13 Recording of image on a holographic plate 2-21
2.14 Reconstruction of image from a hologram 2-22
2.15 Applications of holography 2-22
Formula 2-23
Solved Problems 2-23
Multiple-choice Questions 2-24
Answers 2-28
Review Questions 2-28
Chapter 3 Fibre Optics and its Applications 3-1
3.1 Introduction 3-1
3.2 Principle of optical fibre, acceptance angle
and acceptance cone 3-1
3.3 Numerical aperture (NA) 3-3
3.4 Step index fibres and graded
index fibres—Transmission of signals in them 3-5
3.5 Differences between step index fibres and
graded index fibres 3-9
3.6 Differences between single mode fibres and
multimode fibres 3-9
3.7 Attenuation in optical fibres 3-10
3.8 Optical fibres in communication 3-12
3.9 Advantages of optical fibres in communication 3-13
3.10 Fibre optic sensing applications 3-14
3.11 Applications of optical fibres in medical field 3-17
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Contents vii
Formulae 3-17
Solved Problems 3-18
Multiple-choice Questions 3-22
Answers 3-25
Review Questions 3-25
Chapter 4 Quantum Physics 4-1
4.1 Variation of mass with velocity 4-1
4.2 Mass–energy equivalence 4-1
4.3 Energy and momentum relation 4-2
4.4 Black body radiation 4-3
4.5 The ultra-violet catastrophe 4-7
4.6 Derivation of different laws from
Planck’s radiation law 4-7
4.7 Compton effect 4-10
4.8 Wave–particle duality–de Broglie
hypothesis–Matter waves 4-11
4.9 Davisson–Germer experiment 4-14
4.10 Wave packet 4-17
4.11 Heisenberg uncertainty principle 4-19
Formulae 4-21
Solved Problems 4-21
Multiple-choice Questions 4-26
Answers 4-28
Review Questions 4-28
Chapter 5 Crystal Physics 5-1
5.1 Introduction 5-1
5.2 Space lattice (or) crystal lattice 5-2
5.3 The basis and crystal structure 5-3
5.4 Unit cell and lattice parameters 5-3
5.5 Crystal systems and Bravais lattices 5-4
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viii Contents
5.6 Structure and packing fractions of
simple cubic [SC] structure 5-8
5.7 Structure and packing fractions of
body-centred cubic [BCC] structure 5-9
5.8 Structure and packing fractions of face-centred
cubic [FCC] structure 5-10
5.9 Calculation of lattice constant 5-11
5.10 Burgers vector 5-12
Formula 5-13
Solved Problems 5-13
Multiple-choice Questions 5-15
Answers 5-17
Review Questions 5-17

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Preface
The contents of Engineering Physics-I have been designed to cater to the needs of B.Tech. students at
Anna University. The book follows a simple narrative style with emphasis on clarity. The concepts are
treated rigorously to help students gain a deep-seated understanding of the key elements intrinsic to the
subject. To this end, a list of important formulae, solved problems, multiple-choice questions and review
questions have been included at the end of each chapter. These pedagogical elements would prepare the
student-reader to face both internal tests and term-end examinations with ease. Further, a collection of
model question papers with solutions are included to enhance the book’s value as an undergraduate text.
Engineering Physics-I deals with the physics of substances that are of practical utility. This book
focuses on the complete Anna University syllabus, which includes ultrasonics, lasers, fibre optics and
its applications, quantum physics and crystal physics.
I hope this book will be beneficial to both students and teachers of physics at various engineering
colleges. Comments, feedback and suggestions for the improvement of this book are welcome. Any
error that may have crept into the book inadvertently may kindly be brought to my notice or to that
of the publisher.
Acknowledgements
I thank Dr M. Mohan Babu, cine artiste, former MP and chairman, Sree Vidyanikethan educational
institutions, for providing a congenial atmosphere and for encouraging me to write this book.
I am obliged to T. Gopal Rao, Special Officer, Sree Vidyanikethan Educational Trust, for his
moral support. I am grateful to Professor V. Sreenivasulu, Director; Professor D. Jatin Das, the Dean
of Freshmen; Professor Radhamani, Head of the General Department and the former principals,
Professor B. V. Subba Rao and Professor M. R. Kodali, of Sree Vidyanikethan Engineering College
(SVEC) for their encouragement and support. They were instrumental in giving me the needed impe-
tus to bring out this book.
I appreciate the contribution of the team at Pearson Education, especially that of Thomas Mathew
Rajesh, M. E. Sethurajan, Sandhya Jayadev and Jennifer Sargunar in bringing this work to fruition.
I am indebted to my guide, Dr M. Krishnaiah, Professor of Physics, S. V. University, Tirupati, for
his valuable suggestions to enhance the worth of this book. I am also grateful to all my students and
colleagues at SVEC for evincing keen interest in the making of this book.
Last, but not the least, I am eternally thankful to the goddess Sree Sallapuramma for granting me
the perseverance and commitment to complete this book.
Mani Naidu
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