ENGINEERING

PHYSICS

Third Edition

K. Ra jagopal

HPI

PIHPIH

Lse

ra

Obj ct b ae e m

Object

Ref e e b mer nc ea

ok UV Title only

ENGINEERING PHYSICS

ENGINEERING PHYSICSTHIRD EDITION

K. RajagopalProfessor of Physics

Government College of EngineeringTirunelveli

Delhi-1100922015

ENGINEERING PHYSICS, Third EditionK. Rajagopal

© 2015 by PHI Learning Private Limited, Delhi. All rights reserved. No part of this book may be reproduced in any form, by mimeograph or any other means, without permission in writing from the publisher.

ISBN-978-81-203-5136-3

The export rights of this book are vested solely with the publisher.

Fifth Printing (Third Edition) … … August, 2015

Published by Asoke K. Ghosh, PHI Learning Private Limited, Rimjhim House, 111,Patparganj Industrial Estate, Delhi-110092 and Printed by Rajkamal Electric Press, B-35/9,G.T. Karnal Road Industrial Area, Delhi-110033.

v

CONTENTS

Preface xviiPreface to the First Edition xix

1. ELASTICITY ............................................................................................... 1–451.1 Introduction 11.2 Stress 1

1.2.1 Tensile Stress 21.2.2 Compressional Stress 21.2.3 Normal Stress 21.2.4 Tangential or Shearing Stress 2

1.3 Strain 21.3.1 Longitudinal or Linear Strain 21.3.2 Bulk or Volumetric Strain 21.3.3 Shear Strain 3

1.4 Hooke’s Law 31.4.1 Stress–Strain Diagram 41.4.2 Some Peculiar Phenomena Associated with Elastic Behaviour of Solids 5

1.5 Working Stress and Factors of Safety 61.6 Factors Affecting Elasticity 6

1.6.1 Effect of Hammering, Rolling and Annealing 61.6.2 Effect of Impurities 61.6.3 Effect of Change of Temperature 7

1.7 Various Kinds of Moduli of Elasticity 71.7.1 Young’s Modulus (E or y) 71.7.2 Bulk Modulus (k) 81.7.3 Rigidity Modulus 9

1.8 Relationship between Three Modulii of Elasticity 91.9 Poisson’s Ratio (g) 111.10 Torsion on Cylindrical Bodies such as Wires or Rods 17

1.10.1 Introduction 171.10.2 Expression for the Couple per Unit Twist of the Wire 171.10.3 Efficacy of a Hollow Shaft 191.10.4 Shafts and their Applications 19

vi Contents

1.10.5 Torsional Pendulum 201.10.6 Torsional Oscillations 201.10.7 Determination of Rigidity Modulus of the Wire Using Torsional Pendulum 21

1.11 Beams 261.11.1 Introduction 261.11.2 Bending Moment of a Beam Fixed at One End but Loaded at the Other End 271.11.3 Expression for Bending Moment 281.11.4 Cantilevers 291.11.5 Depression of the Free End of a Cantilever 301.11.6 Depression of the Free End of the Cantilever (Alternative Method) 321.11.7 Applications of Cantilevers 341.11.8 A Beam Supported on Two Knife Edges and Loaded in the Middle

(Non-uniform Bending) 341.11.9 Uniform Bending—Elevation of the Mid Point of the Beam Supported

Symmetrically on Two Knife Edges and Equally Loaded at the Ends 351.11.10 Experimental Methods of Determination of Young’s Modulus 371.11.11 Application of Beams (Shape ‘I’ beam) 40

1.12 Summary 42Short Answer Questions 43Long Answer Questions 44Numerical Problems 44

2. ACOUSTICS OF BUILDINGS................................................................... 46–712.1 Introduction 462.2 Characteristics of Musical Sound 462.3 Unit of Loudness 49

2.3.1 Measurement of Loudness 492.4 Acoustics of Buildings: Architectural Features 562.5 Acoustical Demands of an Auditorium 57

2.5.1 Proper Reverberation 572.5.2 Echoes 592.5.3 Design of the Hall 592.5.4 Shape of Walls and Ceiling 602.5.5 Echelon Effect 602.5.6 Extraneous Noises 60

2.6 Sabine’s Reverberation Formula 602.7 Absorption Coefficient 652.8 Determination of Absorption Coefficient 662.9 Summary 68Short Answer Questions 69Long Answer Questions 70Numerical Problems 70

3. ULTRASONICS ...................................................................................... 72–1023.1 Introduction 723.2 Generation of Ultrasonics 73

Contents vii

3.3 Piezoelectric Effect 733.4 Quartz Crystal 743.5 Piezoelectric Generator 77

3.5.1 Advantages of Piezoelectric Generator 793.6 Magnetostriction Effect 803.7 Magnetostriction Oscillator 81

3.7.1 Advantages and Disadvantages of Magnetostriction Oscillator 813.8 Detection of Ultrasonics 823.9 Properties of Ultrasonics 833.10 Determination of Wavelength and Velocity of Ultrasonic Waves in Liquids 843.11 Industrial Applications of Ultrasonics in Engineering 85

3.11.1 Ultrasonic Cleaning 853.11.2 Ultrasonic Drilling 863.11.3 Ultrasonic Welding 873.11.4 Ultrasonic Soldering 88

3.12 Sonar (sound navigation and ranging) 893.13 Ultrasonic Flaw Detection 90

3.13.1 Introduction 903.13.2 Principle of Operation 903.13.3 Testing Devices 903.13.4 Testing Methods 933.13.5 Visual Display Units 933.13.6 Advantages of Ultrasonic NDT 953.13.7 Limitations of Ultrasonic NDT 953.13.8 Applications of Ultrasonic NDT 95

3.14 Medical Applications of Ultrasonics 953.14.1 Introduction 953.14.2 Sonography 953.14.3 Ultrasonic Imaging Techniques 963.14.4 Different Modes of Scanning 973.14.5 Doppler Sonography 973.14.6 Therapeutic Applications of Ultrasound 983.14.7 Advantages of Ultrasonics 983.14.8 Limitations of Ultrasonics 993.14.9 Risks and Side Effects 99

3.15 Other Applications of Ultrasonics 993.16 Summary 100Short Answer Questions 101Long Answer Questions 102Numerical Problems 102

4. CRYSTAL PHYSICS............................................................................. 103–1444.1 Introduction 1034.2 Space Lattice 1044.3 Translation Vectors 1044.4 The Basis and Crystal Structure 105

viii Contents

4.5 Unit Cell and Lattice Parameters 1054.6 Bravais Lattices 1084.7 The Cubic Crystal 1104.8 Important Parameters of Cubic Lattices 110

4.8.1 Number of Atoms Per Unit Cell 1104.8.2 Coordination Number 1114.8.3 Atomic Radius 1114.8.4 Packing Density or Packing Factor 113

4.9 Calculation of Lattice Constant 1144.10 Some Crystal Structures 115

4.10.1 Structure of Diamond 1154.10.2 Zinc Blende 1184.10.3 Caesium Chloride 1184.10.4 Barium Titanate 1194.10.5 Sodium Chloride 119

4.11 Effect of Temperature and Pressure on Crystal Structures 1194.12 Close-packed Structures 1204.13 Hexagonally Close-packed Structure (HCP) 1224.14 Directions and Miller Indices 1254.15 Rules for Finding Miller Indices 1264.16 Important Features of Miller Indices 1264.17 Miller Indices for a Cubic Crystal 1274.18 Relation between Interplanar Spacing d and Cube Edge a 1274.19 Allotropy and Polymorphism 131

4.19.1 Crystal Growth Techniques 1324.19.2 Solution Growth Method 1324.19.3 Melt-growth Process 1334.19.4 Floating Zone Method (Bridgeman Method) 1344.19.5 Production of Single Crystal by Czocharalski Method 1344.19.6 Vapour Deposition Technique 135

4.20 Crystal Imperfections 1364.20.1 Point Defects 1364.20.2 Effect of Point Defects 1384.20.3 Line Defects 1384.20.4 Properties of Dislocations 1404.20.5 Surface Defects 140

4.21 Summary 142Short Answer Questions 143Long Answer Questions 143Numerical Problems 144

5. WAVE OPTICS ..................................................................................... 145–1735.1 Introduction 1455.2 Michelson’s Interferometer 145

5.2.1 Applications 1475.3 Polarization 149

5.3.1 Plane Polarized Light 150

Contents ix

5.3.2 Polarization by Reflection 1515.3.3 Plane Polarized Light Using Piles of Plates 1525.3.4 Double Refraction 1525.3.5 Elliptically and Circularly Polarized Light 1535.3.6 Retarding Plates 1555.3.7 Production of Plane, Circular and Elliptically Polarized Light 1565.3.8 Detection of Plane, Circular, and Elliptically Polarized Light 1585.3.9 Analysis of the Given Beam of Light 159

5.4 Photoelasticity 1615.4.1 Stress Optic Law 1625.4.2 Relation between Principal Stresses and Angular Phase Difference 1625.4.3 Plane Polariscope 1645.4.4 Circular Polariscope (Photoelastic Bench) 1675.4.5 Applications of Photoelasticity 168

5.5 Summary 168Short Answer Questions 171Long Answer Questions 172Numerical Problems 172

6. LASERS ................................................................................................ 174–2046.1 Introduction 1746.2 Properties of Lasers 1746.3 Stimulated Absorption, Spontaneous Emission and Stimulated Emission 177

6.3.1 Stimulated Absorption 1776.3.2 Spontaneous and Stimulated Emission 178

6.4 Relation between Einstein’s A and B Coefficients 1796.5 Population Inversion 1806.6 Pumping 1816.7 Main Components of a Laser 1826.8 Nd:Yag Laser 1836.9 Helium–Neon Laser 184

6.9.1 Apparatus Construction 1856.9.2 Operations 1856.9.3 Important Features 1876.9.4 Advantages 1876.9.5 Uses 187

6.10 CO2 Laser 1876.11 Semiconductor Lasers 190

6.11.1 Homojunction Laser 1906.11.2 Heterojunction Semiconductor Laser 192

6.12 Applications of Laser in Material Processing 1946.12.1 Laser Cutting 1946.12.2 Laser Welding 1956.12.3 Hole Drilling 1966.12.4 Other Applications 1966.12.5 CD-ROM (Compact Disk Read Only Memory) 196

Engineering Physics

Publisher : PHI Learning ISBN : 9788120351363 Author : RAJAGOPAL, K.

Type the URL : http://www.kopykitab.com/product/7743

Get this eBook

25%OFF