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F51-pref.qxd 3/17/00 10:11 AM Page v PREFACE Features In spite of the numerous textbooks on circuit analysis available in the market, students often find the course difficult to learn. The main objective of this book is to present circuit analysis in a manner that is clearer, more interesting, and easier to understand than earlier texts. This objective is achieved in the following ways: • A course in circuit analysis is perhaps the first exposure students have to electrical engineering. We have included several features to help students feel at home with the subject. Each chapter opens with either a historical profile of some electrical engineering pioneers to be mentioned in the chapter or a career discussion on a subdiscipline of electrical engineering. An introduction links the chapter with the previous chapters and states the chapter’s objectives. The chapter ends with a summary of the key points and formulas. • All principles are presented in a lucid, logical, step-by-step manner. We try to avoid wordiness and superfluous detail that could hide concepts and impede understanding the material. • Important formulas are boxed as a means of helping students sort what is essential from what is not; and to ensure that students clearly get the gist of the matter, key terms are defined and highlighted. • Marginal notes are used as a pedagogical aid. They serve multiple uses—hints, cross-references, more exposition, warnings, reminders, common mistakes, and problem-solving insights. • Thoroughly worked examples are liberally given at the end of every section. The examples are regarded as part of the text and are explained clearly, without asking the reader to fill in missing steps. Thoroughly worked examples give students a good understanding of the solution and the confidence to solve problems themselves. Some of the problems are solved in two or three ways to facilitate an understanding and comparison of different approaches. • To give students practice opportunity, each illustrative example is immediately followed by a practice problem with the answer. The students can follow the example step-by-step to solve the practice problem without flipping pages or searching the end of the book for answers. The practice prob- lem is also intended to test students’ understanding of the preceding example. It will reinforce their grasp of the material before moving to the next section. • In recognition of ABET’s requirement on integrating computer tools, the use of PSpice is encouraged in a student-friendly manner. Since the Windows version of PSpice is becoming popular, it is used instead of the MS-DOS version. PSpice is covered early so that students can use it throughout the text. Appendix D serves as a tutorial on PSpice for Windows. • The operational amplifier (op amp) as a basic element is introduced early in the text. • To ease the transition between the circuit course and signals/systems courses, Fourier and Laplace transforms are covered lucidly and thoroughly. • The last section in each chapter is devoted to applications of the concepts covered in the chapter. Each chapter has at least one or two practical problems or devices. This helps students apply the concepts to real-life situations. • Ten multiple-choice review questions are provided at the end of each chapter, with answers. These are intended to cover the little “tricks” that the examples and end-of-chapter problems may not cover. They serve as a self-test device and help students determine how well they have mastered the chapter. Organization This book was written for a two-semester or three-semester course in linear circuit analysis. The book may also be used for a one-semester course by a proper selection of chapters and sections. It is broadly divided into three parts. • Part 1, consisting of Chapters 1 to 8, is devoted to dc circuits. It covers the fundamental laws and theorems, circuit techniques, passive and active elements. • Part 2, consisting of Chapters 9 to 14, deals with ac circuits. It introduces phasors, sinusoidal steadystate analysis, ac power, rms values, three-phase systems, and frequency response. • Part 3, consisting of Chapters 15 to 18, is devoted to advanced techniques for network analysis. It provides a solid introduction to the Laplace transform, Fourier series, the Fourier transform, and two-port network analysis. The material in three parts is more than sufficient for a two-semester course, so that the instructor | ▲ ▲ v | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents F51-pref.qxd 3/17/00 10:11 AM Page vi vi PREFACE must select which chapters/sections to cover. Sections marked with the dagger sign (†) may be skipped, explained briefly, or assigned as homework. They can be omitted without loss of continuity. Each chapter has plenty of problems, grouped according to the sections of the related material, and so diverse that the instructor can choose some as examples and assign some as homework. More difficult problems are marked with a star (*). Comprehensive problems appear last; they are mostly applications problems that require multiple skills from that particular chapter. The book is as self-contained as possible. At the end of the book are some appendixes that review solutions of linear equations, complex numbers, mathematical formulas, a tutorial on PSpice for Windows, and answers to odd-numbered problems. Answers to all the problems are in the solutions manual, which is available from the publisher. Prerequisites As with most introductory circuit courses, the main prerequisites are physics and calculus. Although familiarity with complex numbers is helpful in the later part of the book, it is not required. Supplements | ▲ ▲ Solutions Manual—an Instructor’s Solutions Manual is available to instructors who adopt the text. It contains complete solutions to all the end-of-chapter problems. Transparency Masters—over 200 important figures are available as transparency masters for use as overheads. Student CD-ROM—100 circuit files from the book are presented as Electronics Workbench (EWB) files; 15–20 of these files are accessible using the free demo of Electronics Workbench. The students are able to experiment with the files. For those who wish to fully unlock all 100 circuit files, EWB’s full version may be purchased from Interactive Image Technologies for approximately $79.00. The CD-ROM also contains a selection of problem-solving, analysis and design tutorials, designed to further support important concepts in the text. Problem-Solving Workbook—a paperback workbook is for sale to students who wish to practice their problem solving techniques. The workbook contains a discussion of problem solving strategies and 150 additional problems with complete solutions provided. Online Learning Center (OLC)—the Web site for the book will serve as an online learning center for students as a useful resource for instructors. The OLC | e-Text Main Menu will provide access to: 300 test questions—for instructors only Downloadable figures for overhead presentations—for instructors only Solutions manual—for instructors only Web links to useful sites Sample pages from the Problem-Solving Workbook PageOut Lite—a service provided to adopters who want to create their own Web site. In just a few minutes, instructors can change the course syllabus into a Web site using PageOut Lite. The URL for the web site is www.mhhe.com.alexander. Although the textbook is meant to be self-explanatory and act as a tutor for the student, the personal contact involved in teaching is not to be forgotten. The book and supplements are intended to supply the instructor with all the pedagogical tools necessary to effectively present the material. ACKNOWLEDGMENTS We wish to take the opportunity to thank the staff of McGraw-Hill for their commitment and hard work: Lynn Cox, Senior Editor; Scott Isenberg, Senior Sponsoring Editor; Kelley Butcher, Senior Developmental Editor; Betsy Jones, Executive Editor; Catherine Fields, Sponsoring Editor; Kimberly Hooker, Project Manager; and Michelle Flomenhoft, Editorial Assistant. They got numerous reviews, kept the book on track, and helped in many ways. We really appreciate their inputs. We are greatly in debt to Richard Mickey for taking the pain ofchecking and correcting the entire manuscript. We wish to record our thanks to Steven Durbin at Florida State University and Daniel Moore at Rose Hulman Institute of Technology for serving as accuracy checkers of examples, practice problems, and endof-chapter problems. We also wish to thank the following reviewers for their constructive criticisms and helpful comments. Promod Vohra, Northern Illinois University Moe Wasserman, Boston University Robert J. Krueger, University of Wisconsin Milwaukee John O’Malley, University of Florida | Textbook Table of Contents | Problem Solving Workbook Contents F51-pref.qxd 3/17/00 10:11 AM Page vii PREFACE vii | ▲ ▲ Aniruddha Datta, Texas A&M University John Bay, Virginia Tech Wilhelm Eggimann, Worcester Polytechnic Institute A. B. Bonds, Vanderbilt University Tommy Williamson, University of Dayton Cynthia Finelli, Kettering University John A. Fleming, Texas A&M University Roger Conant, University of Illinois at Chicago Daniel J. Moore, Rose-Hulman Institute of Technology Ralph A. Kinney, Louisiana State University Cecilia Townsend, North Carolina State University Charles B. Smith, University of Mississippi H. Roland Zapp, Michigan State University Stephen M. Phillips, Case Western University Robin N. Strickland, University of Arizona David N. Cowling, Louisiana Tech University Jean-Pierre R. Bayard, California State University | e-Text Main Menu Jack C. Lee, University of Texas at Austin E. L. Gerber, Drexel University The first author wishes to express his appreciation to his department chair, Dr. Dennis Irwin, for his outstanding support. In addition, he is extremely grateful to Suzanne Vazzano for her help with the solutions manual. The second author is indebted to Dr. Cynthia Hirtzel, the former dean of the college of engineering at Temple University, and Drs.. Brian Butz, Richard Klafter, and John Helferty, his departmental chairpersons at different periods, for their encouragement while working on the manuscript. The secretarial support provided by Michelle Ayers and Carol Dahlberg is gratefully appreciated. Special thanks are due to Ann Sadiku, Mario Valenti, Raymond Garcia, Leke and Tolu Efuwape, and Ope Ola for helping in various ways. Finally, we owe the greatest debt to our wives, Paulette and Chris, without whose constant support and cooperation this project would have been impossible. Please address comments and corrections to the publisher. | Textbook Table of Contents | C. K. Alexander and M. N. O. Sadiku Problem Solving Workbook Contents F51-pref.qxd 3/17/00 10:11 AM Page ix A NOTE TO THE STUDENT This may be your first course in electrical engineering. Although electrical engineering is an exciting and challenging discipline, the course may intimidate you. This book was written to prevent that. A good textbook and a good professor are an advantage—but you are the one who does the learning. If you keep the following ideas in mind, you will do very well in this course. • This course is the foundation on which most other courses in the electrical engineering curriculum rest. For this reason, put in as much effort as you can. Study the course regularly. • Problem solving is an essential part of the learning process. Solve as many problems as you can. Begin by solving the practice problem following each example, and then proceed to the end-ofchapter problems. The best way to learn is to solve a lot of problems. An asterisk in front of a problem indicates a challenging problem. • Spice, a computer circuit analysis program, is used throughout the textbook. PSpice, the personal computer version of Spice, is the popular standard circuit analysis program at most uni- versities. PSpice for Windows is described in Appendix D. Make an effort to learn PSpice, because you can check any circuit problem with PSpice and be sure you are handing in a correct problem solution. • Each chapter ends with a section on how the material covered in the chapter can be applied to real-life situations. The concepts in this section may be new and advanced to you. No doubt, you will learn more of the details in other courses. We are mainly interested in gaining a general familiarity with these ideas. • Attempt the review questions at the end of each chapter. They will help you discover some “tricks” not revealed in class or in the textbook. A short review on finding determinants is covered in Appendix A, complex numbers in Appendix B, and mathematical formulas in Appendix C. Answers to odd-numbered problems are given in Appendix E. Have fun! C.K.A. and M.N.O.S. | ▲ ▲ ix | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents f51-cont.qxd 3/16/00 4:22 PM Page xi Contents Preface 3.7 3.8 †3.9 3.10 v Acknowledgments vi A Note to the Student PART 1 DC CIRCUITS Chapter 1 1.1 1.2 1.3 1.4 1.5 1.6 †1.7 Review Questions 107 Problems 109 Comprehensive Problems 1 Basic Concepts 3 Introduction 4 Systems of Units 4 Charge and Current 6 Voltage 9 Power and Energy 10 Circuit Elements 13 Applications 15 1.7.1 1.7.2 †1.8 ix Chapter 4 Chapter 2 18 2.1 2.2 †2.3 2.4 2.5 2.6 †2.7 †2.8 25 Basic Laws 2.9 Summary 60 72 Chapter 3 3.1 3.2 3.3 3.4 3.5 †3.6 4.11 Summary Review Questions 153 Problems 154 Comprehensive Problems 41 42 Chapter 5 Methods of Analysis 119 162 Operational Amplifiers 165 Introduction 166 Operational Amplifiers 166 Ideal Op Amp 170 Inverting Amplifier 171 Noninverting Amplifier 174 Summing Amplifier 176 Difference Amplifier 177 Cascaded Op Amp Circuits 181 Op Amp Circuit Analysis with PSpice 183 †5.10 Applications 185 75 Introduction 76 Nodal Analysis 76 Nodal Analysis with Voltage Sources 82 Mesh Analysis 87 Mesh Analysis with Current Sources 92 Nodal and Mesh Analyses by Inspection 95 153 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 Lighting Systems Design of DC Meters Review Questions 61 Problems 63 Comprehensive Problems Circuit Theorems 4.10.1 Source Modeling 4.10.2 Resistance Measurement 27 Introduction 28 Ohm’s Laws 28 Nodes, Branches, and Loops 33 Kirchhoff’s Laws 35 Series Resistors and Voltage Division Parallel Resistors and Current Division Wye-Delta Transformations 50 Applications 54 2.8.1 2.8.2 117 Introduction 120 Linearity Property 120 Superposition 122 Source Transformation 127 Thevenin’s Theorem 131 Norton’s Theorem 137 Derivations of Thevenin’s and Norton’s Theorems 140 4.8 Maximum Power Transfer 142 4.9 Verifying Circuit Theorems with PSpice 144 †4.10 Applications 147 1.9 Summary Review Questions 22 Problems 23 Comprehensive Problems 102 4.1 4.2 4.3 4.4 4.5 4.6 †4.7 TV Picture Tube Electricity Bills Problem Solving 21 Nodal Versus Mesh Analysis 99 Circuit Analysis with PSpice 100 Applications: DC Transistor Circuits Summary 107 5.10.1 Digital-to Analog Converter 5.10.2 Instrumentation Amplifiers 5.11 Summary Review Questions 190 Problems 191 Comprehensive Problems 188 200 | ▲ ▲ xi | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents xii CONTENTS Chapter 6 6.1 6.2 6.3 6.4 6.5 †6.6 Capacitors and Inductors Introduction 202 Capacitors 202 Series and Parallel Capacitors Inductors 211 Series and Parallel Inductors Applications 219 6.6.1 6.6.2 6.6.3 6.7 Summary Chapter 7 216 237 Delay Circuits Photoflash Unit Relay Circuits Automobile Ignition Circuit 7.10 Summary Review Questions 283 Problems 284 Comprehensive Problems Chapter 8 282 Second-Order Circuits 295 Introduction 296 Finding Initial and Final Values 296 The Source-Free Series RLC Circuit 301 The Source-Free Parallel RLC Circuit 308 Step Response of a Series RLC Circuit 314 8.6 Step Response of a Parallel RLC Circuit 319 8.7 General Second-Order Circuits 322 8.8 Second-Order Op Amp Circuits 327 8.9 PSpice Analysis of RLC Circuits 330 †8.10 Duality 332 †8.11 Applications 336 ▲ ▲ 8.11.1 Automobile Ignition System 8.11.2 Smoothing Circuits | 351 Chapter 9 9.7 †9.8 9.9 e-Text Main Menu Sinusoids and Phasors 353 Introduction 354 Sinusoids 355 Phasors 359 Phasor Relationships for Circuit Elements 367 Impedance and Admittance 369 Kirchhoff’s Laws in the Frequency Domain 372 Impedance Combinations 373 Applications 379 9.8.1 9.8.2 Phase-Shifters AC Bridges Summary Review Questions 385 Problems 385 Comprehensive Problems 384 392 Chapter 10 Sinusoidal Steady-State Analysis 10.1 10.2 10.3 10.4 10.5 10.6 293 8.1 8.2 8.3 8.4 8.5 | PART 2 AC CIRCUITS 9.5 9.6 235 Introduction 238 The Source-free RC Circuit 238 The Source-free RL Circuit 243 Singularity Functions 249 Step Response of an RC Circuit 257 Step Response of an RL Circuit 263 First-order Op Amp Circuits 268 Transient Analysis with PSpice 273 Applications 276 7.9.1 7.9.2 7.9.3 7.9.4 340 350 9.1 9.2 9.3 9.4 225 First-Order Circuits 8.12 Summary Review Questions 340 Problems 341 Comprehensive Problems 208 Integrator Differentiator Analog Computer Review Questions 226 Problems 227 Comprehensive Problems 7.1 7.2 7.3 7.4 7.5 7.6 †7.7 7.8 †7.9 201 10.7 10.8 †10.9 Introduction 394 Nodal Analysis 394 Mesh Analysis 397 Superposition Theorem 400 Source Transformation 404 Thevenin and Norton Equivalent Circuits 406 Op Amp AC Circuits 411 AC Analysis Using PSpice 413 Applications 416 10.9.1 10.9.2 Capacitance Multiplier Oscillators 10.10 Summary Review Questions Problems 422 420 421 Chapter 11 AC Power Analysis 11.1 11.2 11.3 11.4 11.5 11.6 †11.7 | Textbook Table of Contents | 393 433 Introduction 434 Instantaneous and Average Power Maximum Average Power Transfer Effective or RMS Value 443 Apparent Power and Power Factor Complex Power 449 Conservation of AC Power 453 434 440 447 Problem Solving Workbook Contents CONTENTS 11.8 †11.9 xiii Power Factor Correction Applications 459 11.9.1 11.9.2 11.10 Summary Review Questions 465 Problems 466 Comprehensive Problems Power Measurement Electricity Consumption Cost 464 474 12.11 Summary Review Questions 517 Problems 518 Comprehensive Problems †13.9 13.10 Summary Review Questions 570 Problems 571 Comprehensive Problems ▲ ▲ | | †14.11 14.11.1 14.11.2 14.11.3 619 Magnitude Scaling Frequency Scaling Magnitude and Frequency Scaling 622 626 Radio Receiver Touch-Tone Telephone Crossover Network 631 640 527 PART 3 ADVANCED CIRCUIT ANALYSIS 643 Chapter 15 The Laplace Transform 645 Transformer as an Isolation Device Transformer as a Matching Device Power Distribution 569 582 583 Introduction 584 Transfer Function 584 The Decibel Scale 588 e-Text Main Menu First-Order Lowpass Filter First-Order Highpass Filter Bandpass Filter Bandreject (or Notch) Filter PSpice Applications 14.12 Summary 525 613 14.10 Frequency Response Using Review Questions 633 Problems 633 Comprehensive Problems Chapter 14 Frequency Response 14.1 14.2 †14.3 Scaling 14.9.1 14.9.2 14.9.3 516 Introduction 528 Mutual Inductance 528 Energy in a Coupled Circuit 535 Linear Transformers 539 Ideal Transformers 545 Ideal Autotransformers 552 Three-Phase Transformers 556 PSpice Analysis of Magnetically Coupled Circuits 559 Applications 563 13.9.1 13.9.2 13.9.3 †14.9 Lowpass Filter Highpass Filter Bandpass Filter Bandstop Filter Active Filters 14.8.1 14.8.2 14.8.3 14.8.4 Three-Phase Power Measurement Residential Wiring Chapter 13 Magnetically Coupled Circuits 13.1 13.2 13.3 13.4 13.5 13.6 †13.7 13.8 14.8 477 Introduction 478 Balanced Three-Phase Voltages 479 Balanced Wye-Wye Connection 482 Balanced Wye-Delta Connection 486 Balanced Delta-Delta Connection 488 Balanced Delta-Wye Connection 490 Power in a Balanced System 494 Unbalanced Three-Phase Systems 500 PSpice for Three-Phase Circuits 504 Applications 508 12.10.1 12.10.2 Bode Plots 589 Series Resonance 600 Parallel Resonance 605 Passive Filters 608 14.7.1 14.7.2 14.7.3 14.7.4 Chapter 12 Three-Phase Circuits 12.1 12.2 12.3 12.4 12.5 12.6 12.7 †12.8 12.9 †12.10 14.4 14.5 14.6 14.7 457 | Textbook Table of Contents | 15.1 15.2 15.3 15.4 Introduction 646 Definition of the Laplace Transform 646 Properties of the Laplace Transform 649 The Inverse Laplace Transform 15.4.1 15.4.2 15.4.3 15.5 15.6 15.7 †15.8 †15.9 659 Simple Poles Repeated Poles Complex Poles Applicaton to Circuits 666 Transfer Functions 672 The Convolution Integral 677 Application to Integrodifferential Equations 685 Applications 687 15.9.1 15.9.2 15.10 Summary Network Stability Network Synthesis 694 Problem Solving Workbook Contents xiv CONTENTS Review Questions 696 Problems 696 Comprehensive Problems 17.8 705 Chapter 16 The Fourier Series 16.1 16.2 16.3 16.4 16.5 16.6 16.7 †16.8 16.8.1 16.8.2 16.9 Even Symmetry Odd Symmetry Half-Wave Symmetry Summary Review Questions 751 Problems 751 Comprehensive Problems 746 †17.7 ▲ ▲ | | 18.10 Summary 833 844 Appendix A Solution of Simultaneous Equations Using 758 759 Introduction 760 Definition of the Fourier Transform Properties of the Fourier Transform Circuit Applications 779 Parseval’s Theorem 782 Comparing the Fourier and Laplace Transforms 784 Applications 785 17.7.1 17.7.2 Transistor Circuits Ladder Network Synthesis Review Questions 834 Problems 835 Comprehensive Problems 749 Chapter 17 Fourier Transform 17.1 17.2 17.3 17.4 17.5 17.6 18.9.1 18.9.2 Spectrum Analyzers Filters 795 Introduction 796 Impedance Parameters 796 Admittance Parameters 801 Hybrid Parameters 804 Transmission Parameters 809 Relationships between Parameters 814 Interconnection of Networks 817 Computing Two-Port Parameters Using PSpice 823 Applications 826 †18.9 Discrete Fourier Transform Fast Fourier Transform Applications 794 Chapter 18 Two-Port Networks 18.1 18.2 18.3 18.4 18.5 †18.6 18.7 18.8 Circuit Applicatons 727 Average Power and RMS Values 730 Exponential Fourier Series 734 Fourier Analysis with PSpice 740 16.7.1 16.7.2 789 707 Introduction 708 Trigonometric Fourier Series 708 Symmetry Considerations 717 16.3.1 16.3.2 16.3.3 Summary Review Questions 790 Problems 790 Comprehensive Problems Cramer’s Rule 845 Appendix B Complex Numbers 851 Appendix C Mathematical Formulas 760 766 Appendix D PSpice for Windows 859 865 Appendix E Answers to Odd-Numbered Problems Selected Bibliography Index 893 929 933 Amplitude Modulation Sampling e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents P A R T 1 DC CIRCUITS Chapter 1 Basic Concepts Chapter 2 Basic Laws Chapter 3 Methods of Analysis Chapter 4 Circuit Theorems Chapter 5 Operational Amplifier Chapter 6 Capacitors and Inductors Chapter 7 First-Order Circuits Chapter 8 Second-Order Circuits | ▲ ▲ 1 | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents