Circuit Theory and Networks Fourth Edition WBUT-2014

742 Pages·2015·12.012 MB·English

by  S. P. Ghosh

Circuit Theory and
Networks
Fourth Edition
WBUT-2014
About the Authors
S P Ghosh did his BE (Hon.) in Electrical Engineering from Regional Engineering
College (presently, National Institute of Technology), Durgapur, and received a
Master of Electrical Engineering degree from Jadavpur University, Kolkata, with
specialization in High Voltage Engineering. He has over 12 years of teaching
experience. Presently, he is Head of the Department of Electrical Engineering at
College of Engineering and Management, Kolaghat. He is also pursuing a PhD at
NIT, Agartala. Prof Ghosh has authored six different books on Electromagnetic Field
Theory and Circuit Theory. He has also presented several papers in national and
international conferences. His areas of interest include Power Systems, Electrical
Machines, Artifi cial Neural Networks, and related topics.
Ajoy Kumar Chakraborty received his BEE (Hon.) from Jadavpur University,
Kolkata, MTech in Power System Engineering from IIT Kharagpur and PhD
(Engineering) again from Jadavpur University. Presently, he is the Dean (Planning
and Development) at NIT, Agartala. He taught at College of Engineering and
Management, Kolaghat, for 12 years. He also worked as a Lecturer in NIT Silchar
for fi ve years. He has served in a number of industries, namely, CESC Ltd. and
the Tinplate Company of India Ltd. (a Tata Enterprise) for over fourteen years
before joining this institute. He is a Fellow of the Institute of Engineers (India),
Chartered Engineer, Member IET (UK) and a Life Member of ISTE. He has
presented several technical papers in national and international conferences, has published his essays
in reputed journals, and has visited three foreign countries to deliver technical lectures. As an enthusiastic
teacher, he is actively involved in guiding MTech and PhD (Engineering) scholars. His research interests
are in the fi eld of Power System Protection, Economic Operation of Power Systems, Deregulated Power
System, HVDC, and related topics.
Circuit Theory and
Networks
Fourth Edition
WBUT-2014
S P Ghosh
Head
Department of Electrical Engineering
College of Engineering and Management
Kolaghat, West Bengal
A K Chakraborty
Dean (Planning and Development) and Associate Professor
Department of Electrical Engineering
National Institute of Technology (NIT) Agartala, Tripura
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Circuit Theory and Networks, 4e
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Dedicated to our families
Wife, Lipika
and
My Parents
S P Ghosh
Wife, Indira
Daughters, Amrita and Ananya
A K Chakraborty
Contents
Preface xi
Roadmaps to the Syllabus xiv
1. Introduction to Different Types of Systems 1.1–1.21
1.1 Introduction 1.1
1.2 Concepts of Signals and Systems 1.1
1.3 Different Types of Systems 1.2
1.4 Different Types of Signals 1.7
1.5 Some Satandards Signals 1.10
1.6 Singularities Signals 1.12
Solved Problems 1.14
Multiple-Choice Questions 1.18
Exercises 1.20
Short-Answer Type Questions 1.20
Answers to Multiple-Choice Questions 1.21
2. Introduction to Circuit-Theory Concepts 2.1–2.84
2.1 Introduction 2.1
2.2 Some Basic Terminologies of Electric Circuits 2.1
2.3 Different Notations 2.5
2.4 Basic Circuit Elements 2.5
2.5 Passive Circuit Elements 2.6
2.6 Types of Electrical Energy Sources 2.14
2.7 Fundamental Laws 2.16
2.8 Source Transformation 2.18
2.9 Network Analysis Techniques 2.20
2.10 Duality 2.23
2.11 Star-Delta Conversion Technique 2.26
Solved Problems 2.27
Multiple-Choice Questions 2.61
Exercises 2.78
Short-Answer Type Questions 2.83
Answers to Multiple-Choice Questions 2.84
Contents vii
3. Magnetically Coupled Circuits 3.1–3.54
3.1 Introduction 3.1
3.2 Self-Inductance 3.1
3.3 Coupled Inductor 3.2
3.4 Mutual Inductance 3.3
3.5 Mutual Inductance between Two Coupled Inductors 3.5
3.6 Dot Convention 3.6
3.7 Coeffi cient of Coupling 3.7
3.8 Inductive Coupling 3.10
3.9 Linear Transformer 3.12
3.10 Determination of Equivalent T and p Circuit of Linear Transformer 3.13
3.11 Ideal Transformer 3.15
3.12 Tuned Coupled Circuits 3.18
Solved Problems 3.25
Summary 3.49
Exercises 3.50
Short-Answer Type Questions 3.53
4. Network Topology (Graph Theory) 4.1–4.54
4.1 Introduction 4.1
4.2 Graph of a Network 4.1
4.3 Terminology 4.2
4.4 Concept of Tree 4.3
4.5 Incidence Matrix [A ] 4.4
a
4.6 Number of Possible Trees of a Graph 4.6
4.7 Tie-Set Matrix and Loop Currents 4.7
4.8 Cut-Set Matrix and Node-Pair Potential 4.9
4.9 Formulation of Network Equilibrium Equations 4.13
4.10 Solution of Equilibrium Equations 4.15
Solved Problems 4.16
Multiple-Choice Questions 4.47
Exercises 4.51
Short-Answer Type Questions 4.53
Answers to Multiple-Choice Questions 4.54
5. Network Theorems 5.1–5.87
5.1 Introduction 5.1
5.2 Network Theorems 5.1
Solved Problems 5.14
Multiple-Choice Questions 5.70
Exercises 5.79
Short-Answer Type Questions 5.86
Answers to Multiple-Choice Questions 5.87
viii Contents
6. Laplace Transform and its Applications 6.1–6.117
6.1 Introduction 6.1
6.2 Advantages of Laplace Transform Method 6.1
6.3 Defi nition of Laplace Transform 6.2
6.4 Basic Theorems of Laplace Transform 6.2
6.5 Laplace Transform of Some Basic Functions 6.4
6.6 Laplace Transform Table 6.8
6.7 Laplace Transform of Periodic Functions 6.10
6.8 Singularity Functions and Waveform Synthesis 6.11
6.9 Inverse Laplace Transform 6.14
6.10 Applications of Laplace Transform 6.18
6.11 Application of Laplace Transform Method to Circuit Analysis 6.20
6.12 Transient Analysis of Electric Circuits using Laplace Transform 6.21
6.13 Steps for Circuit Analysis using Laplace Transform Method 6.44
6.14 Concept of Convolution Theorem 6.44
Solved Problems 6.46
Multiple-Choice Questions 6.90
Exercises 6.110
Short-Answer Type Questions 6.116
Answers to Multiple-Choice Questions 6.117
7. Two-Port Network 7.1–7.71
7.1 Introduction 7.1
7.2 Relationships of Two-Port Variables 7.1
7.3 Conditions for Reciprocity and Symmetry 7.4
7.4 Interrelationships between Two-Port Parameters 7.7
7.5 Interconnection of Two-Port Networks 7.10
7.6 Two-Port Network Functions 7.12
Solved Problems 7.13
Multiple-Choice Questions 7.58
Exercises 7.65
Short-Answer Type Questions 7.70
Answers to Multiple-Choice Questions 7.71
8. Fourier Series and Fourier Transform 8.1–8.72
Part I: Fourier Series
8.1 Introduction 8.1
8.2 Defi nition of Fourier Series 8.2
8.3 Dirichlet’s Conditions 8.2
8.4 Fourier Analysis 8.2
8.5 Steady-State Response of Network to Periodic Signals 8.12
Part II: Fourier Transform
8.6 Introduction 8.16
8.7 Defi nition of Fourier Transform 8.16
Contents ix
8.8 Convergence of Fourier Transform 8.17
8.9 Fourier Transform of Some Functions 8.18
8.10 Properties of Fourier Transforms 8.21
8.11 Energy Density and Parseval’s Theorem 8.24
8.12 Comparison between Fourier Transform and Laplace Transform 8.26
8.13 Steps for Application of Fourier Transform to Circuit Analysis 8.26
Solved Problems 8.27
Multiple-Choice Questions 8.64
Exercises 8.67
Short-Answer Type Questions 8.70
Answers to Multiple-Choice Questions 8.72
9. Filter Circuits 9.1–9.39
9.1 Introduction 9.1
9.2 Filter 9.2
9.3 Classifi cation of Filters 9.2
9.4 Advantages of Active Filters over Passive Filters 9.5
9.5 Application of Active Filters 9.5
9.6 Low-pass Active Filter 9.5
9.7 High-pass Active Filter 9.10
9.8 Band-Pass Active Filter 9.13
9.9 Band-Reject (Notch) Active Filter 9.21
9.10 Filter Approximation 9.24
9.11 All-Pass Active Filter 9.34
Multiple-Choice Questions 9.35
Exercises 9.38
Short-Answer Type Questions 9.39
Answers to Multiple-Choice Questions 9.39
10. Resonance 10.1–10.59
10.1 Introduction 10.1
10.2 Series Resonance or Voltage Resonance 10.1
10.3 Parallel Resonance or Current Resonance or Anti-Resonance 10.11
10.4 Relation Between Damping Ratio and Quality Factor 10.16
10.5 A More Realistic Parallel Resonant Circuit 10.17
10.6 Comparison of Series and Parallel Resonance 10.27

10.7 Universal Resonance Curve 10.27
10.8 Applications of Resonance 10.28
Solved Problems 10.30
Summary 10.53
Exercises 10.54
Questions 10.57
x Contents
Solution of 2011 WBUT Paper SQP.1–SQP.22
Solution of 2012 WBUT Paper SQP.1–SQP.18
Solution of 2013 WBUT Paper SQP.1–SQP.18