alexander sadiku PDF

Preview

Summary

ale29559_IFC.qxd 07/11/2008 07:40 PM Page 2 PRACTICAL APPLICATIONS Each chapter devotes material to practical applications of the concepts covered in Fundamentals of Electric Circuits to help the reader apply the concepts to real-life situations. Here is a sampling of the practical applications fou...

Description

ale29559_IFC.qxd

07/11/2008

07:40 PM

Page 2

PRACTICAL APPLICATIONS Each chapter devotes material to practical applications of the concepts covered in Fundamentals of Electric Circuits to help the reader apply the concepts to real-life situations. Here is a sampling of the practical applications found in the text: • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

Rechargeable flashlight battery (Problem 1.11) Cost of operating toaster (Problem 1.25) Potentiometer (Section 2.8) Design a lighting system (Problem 2.61) Reading a voltmeter (Problem 2.66) Controlling speed of a motor (Problem 2.74) Electric pencil sharpener (Problem 2.78) Calculate voltage of transistor (Problem 3.86) Transducer modeling (Problem 4.87) Strain gauge (Problem 4.90) Wheatstone bridge (Problem 4.91) Design a six-bit DAC (Problem 5.83) Instrumentation amplifier (Problem 5.88) Design an analog computer circuit (Example 6.15) Design an op amp circuit (Problem 6.71) Design analog computer to solve differential equation (Problem 6.79) Electric power plant substation—capacitor bank (Problem 6.83) Electronic photo flash unit (Section 7.9) Automobile ignition circuit (Section 7.9) Welding machine (Problem 7.86) Airbag igniter (Problem 8.78) Electrical analog to bodily functions—study of convulsions (Problem 8.82) Electronic sensing device (Problem 9.87) Power transmission system (Problem 9.93) Design a Colpitts oscillator (Problem 10.94) Stereo amplifier circuit (Problem 13.85) Gyrator circuit (Problem 16.69) Calculate number of stations allowable in AM broadcast band (Problem 18.63) Voice signal—Nyquist rate (Problem 18.65)

ale29559_IFC.qxd

07/11/2008

07:40 PM

Page 3

COMPUTER TOOLS promote flexibility and meet ABET requirements • PSpice is introduced in Chapter 3 and appears in special sections throughout the text. Appendix D serves as a tutorial on PSpice for Windows for readers not familiar with its use. The special sections contain examples and practice problems using PSpice. Additional homework problems at the end of each chapter also provide an opportunity to use PSpice. • MATLAB® is introduced through a tutorial in Appendix E to show its usage in circuit analysis. A number of examples and practice problems are presented throughout the book in a manner that will allow the student to develop a facility with this powerful tool. A number of end-of-chapter problems will aid in understanding how to effectively use MATLAB. • KCIDE for Circuits is a working software environment developed at Cleveland State University. It is designed to help the student work through circuit problems in an organized manner following the process on problem-solving discussed in Section 1.8. Appendix F contains a description of how to use the software. Additional examples can be found at the web site, http://kcide.fennresearch.org/. The actual software package can be downloaded for free from this site. One of the best benefits from using this package is that it automatically generates a Word document and/or a PowerPoint presentation.

CAREERS AND HISTORY of electrical engineering pioneers Since a course in circuit analysis may be a student’s first exposure to electrical engineering, each chapter opens with discussions about how to enhance skills that contribute to successful problem-solving or career-oriented talks on a sub-discipline of electrical engineering. The chapter openers are intended to help students grasp the scope of electrical engineering and give thought to the various careers available to EE graduates. The opening boxes include information on careers in electronics, instrumentation, electromagnetics, control systems, engineering education, and the importance of good communication skills. Historicals throughout the text provide brief biological sketches of such engineering pioneers as Faraday, Ampere, Edison, Henry, Fourier, Volta, and Bell.

ale29559_IFC.qxd

07/11/2008

07:40 PM

Page 4

OUR COMMITMENT TO ACCURACY You have a right to expect an accurate textbook, and McGraw-Hill Engineering invests considerable time and effort to ensure that we deliver one. Listed below are the many steps we take in this process. OUR ACCURACY VERIFICATION PROCESS First Round Step 1: Numerous college engineering instructors review the manuscript and report errors to the editorial team. The authors review their comments and make the necessary corrections in their manuscript. Second Round Step 2: An expert in the field works through every example and exercise in the final manuscript to verify the accuracy of the examples, exercises, and solutions. The authors review any resulting corrections and incorporate them into the final manuscript and solutions manual. Step 3: The manuscript goes to a copyeditor, who reviews the pages for grammatical and stylistic considerations. At the same time, the expert in the field begins a second accuracy check. All corrections are submitted simultaneously to the authors, who review and integrate the editing, and then submit the manuscript pages for typesetting. Third Round Step 4: The authors review their page proofs for a dual purpose: 1) to make certain that any previous corrections were properly made, and 2) to look for any errors they might have missed. Step 5: A proofreader is assigned to the project to examine the new page proofs, double check the authors' work, and add a fresh, critical eye to the book. Revisions are incorporated into a new batch of pages which the authors check again. Fourth Round Step 6: The author team submits the solutions manual to the expert in the field, who checks text pages against the solutions manual as a final review. Step 7: The project manager, editorial team, and author team review the pages for a final accuracy check. The resulting engineering textbook has gone through several layers of quality assurance and is verified to be as accurate and error-free as possible. Our authors and publishing staff are confident that through this process we deliver textbooks that are industry leaders in their correctness and technical integrity.

ale29559_fm.qxd

07/28/2008

11:54 AM

Page i

Fundamentals of

Electric Circuits

ale29559_fm.qxd

07/28/2008

11:54 AM

Page ii

ale29559_fm.qxd

07/28/2008

11:54 AM

fourth

Page iii

edition

Fundamentals of

Electric Circuits Charles K. Alexander Department of Electrical and Computer Engineering Cleveland State University

Matthew N. O. Sadiku Department of Electrical Engineering Prairie View A&M University

ale29559_fm.qxd

07/28/2008

11:54 AM

Page iv

FUNDAMENTALS OF ELECTRIC CIRCUITS, FOURTH EDITION Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2009 by The McGraw-Hill Companies, Inc. All rights reserved. Previous editions © 2007, 2004, and 2000. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. Some ancillaries, including electronic and print components, may not be available to customers outside the United States. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 VNH/VNH 0 9 8 ISBN 978–0–07–352955–4 MHID 0–07–352955–9 Global Publisher: Raghothaman Srinivasan Director of Development: Kristine Tibbetts Developmental Editor: Lora Neyens Senior Marketing Manager: Curt Reynolds Project Manager: Joyce Watters Senior Production Supervisor: Sherry L. Kane Lead Media Project Manager: Stacy A. Patch Associate Design Coordinator: Brenda A. Rolwes Cover Designer: Studio Montage, St. Louis, Missouri (USE) Cover Image: Astronauts Repairing Spacecraft: © StockTrek/Getty Images; Printed Circuit Board: Photodisc Collection/Getty Images Lead Photo Research Coordinator: Carrie K. Burger Compositor: ICC Macmillan Inc. Typeface: 10/12 Times Roman Printer: R. R. Donnelley, Jefferson City, MO Library of Congress Cataloging-in-Publication Data Alexander, Charles K. Fundamentals of electric circuits / Charles K. Alexander, Matthew N. O. Sadiku. — 4th ed. p. cm. Includes index. ISBN 978–0–07–352955–4 — ISBN 0–07–352955–9 (hard copy : alk. paper) 1. Electric circuits. I. Sadiku, Matthew N. O. II. Title. TK454.A452 2009 621.319'24—dc22

www.mhhe.com

2008023020

ale29559_fm.qxd

07/28/2008

11:54 AM

Page v

Dedicated to our wives, Kikelomo and Hannah, whose understanding and support have truly made this book possible. Matthew and Chuck

ale29559_fm.qxd

07/28/2008

11:54 AM

Page vi

ale29559_fm.qxd

07/28/2008

11:54 AM

Page vii

Contents Preface xiii Acknowledgments xviii Guided Tour xx A Note to the Student xxv About the Authors xxvii

Chapter 3 3.1 3.2 3.3 3.4 3.5

PART 1

DC Circuits 2

Chapter 1

Basic Concepts 3

3.6 1.1 1.2 1.3 1.4 1.5 1.6 1.7

Introduction 4 Systems of Units 4 Charge and Current 6 Voltage 9 Power and Energy 10 Circuit Elements 15 † Applications 17

3.7 3.8 3.9 3.10

Methods of Analysis 81

Introduction 82 Nodal Analysis 82 Nodal Analysis with Voltage Sources 88 Mesh Analysis 93 Mesh Analysis with Current Sources 98 † Nodal and Mesh Analyses by Inspection 100 Nodal Versus Mesh Analysis 104 Circuit Analysis with PSpice 105 † Applications: DC Transistor Circuits 107 Summary 112 Review Questions 113 Problems 114 Comprehensive Problem 126

1.7.1 TV Picture Tube 1.7.2 Electricity Bills

1.8 1.9

†

Problem Solving 20 Summary 23

Chapter 4

Review Questions 24 Problems 24 Comprehensive Problems 27

4.1 4.2 4.3 4.4 4.5 4.6 4.7

Chapter 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8

Basic Laws 29

Introduction 30 Ohm’s Law 30 † Nodes, Branches, and Loops 35 Kirchhoff’s Laws 37 Series Resistors and Voltage Division 43 Parallel Resistors and Current Division 45 † Wye-Delta Transformations 52 † Applications 58

4.8 4.9 4.10

Circuit Theorems 127

Introduction 128 Linearity Property 128 Superposition 130 Source Transformation 135 Thevenin’s Theorem 139 Norton’s Theorem 145 † Derivations of Thevenin’s and Norton’s Theorems 149 Maximum Power Transfer 150 Verifying Circuit Theorems with PSpice 152 † Applications 155 4.10.1 Source Modeling 4.10.2 Resistance Measurement

4.11

Summary

160

Review Questions 161 Problems 162 Comprehensive Problems 173

2.8.1 Lighting Systems 2.8.2 Design of DC Meters

2.9

Summary 64 Review Questions 66 Problems 67 Comprehensive Problems 78

Chapter 5 5.1 5.2

Operational Amplifiers 175

Introduction 176 Operational Amplifiers 176 vii

ale29559_fm.qxd

07/28/2008

11:54 AM

Page viii

Contents

viii

5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10

Ideal Op Amp 179 Inverting Amplifier 181 Noninverting Amplifier 183 Summing Amplifier 185 Difference Amplifier 187 Cascaded Op Amp Circuits 191 Op Amp Circuit Analysis with PSpice 194 † Applications 196 5.10.1 Digital-to-Analog Converter 5.10.2 Instrumentation Amplifiers

5.11

Summary

199

Review Questions 201 Problems 202 Comprehensive Problems 213

Chapter 6 6.1 6.2 6.3 6.4 6.5 6.6

Introduction 216 Capacitors 216 Series and Parallel Capacitors 222 Inductors 226 Series and Parallel Inductors 230 † Applications 233

Summary

240

Review Questions 241 Problems 242 Comprehensive Problems 251

Chapter 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9

7.10

First-Order Circuits 253

Introduction 254 The Source-Free RC Circuit 254 The Source-Free RL Circuit 259 Singularity Functions 265 Step Response of an RC Circuit 273 Step Response of an RL Circuit 280 † First-Order Op Amp Circuits 284 Transient Analysis with PSpice 289 † Applications 293 7.9.1 7.9.2 7.9.3 7.9.4

8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11

Capacitors and Inductors 215

6.6.1 Integrator 6.6.2 Differentiator 6.6.3 Analog Computer

6.7

Chapter 8

Delay Circuits Photoflash Unit Relay Circuits Automobile Ignition Circuit

Summary

Introduction 314 Finding Initial and Final Values 314 The Source-Free Series RLC Circuit 319 The Source-Free Parallel RLC Circuit 326 Step Response of a Series RLC Circuit 331 Step Response of a Parallel RLC Circuit 336 General Second-Order Circuits 339 Second-Order Op Amp Circuits 344 PSpice Analysis of RLC Circuits 346 † Duality 350 † Applications 353 8.11.1 Automobile Ignition System 8.11.2 Smoothing Circuits

8.12

Summary

356

Review Questions 357 Problems 358 Comprehensive Problems 367

PART 2

AC Circuits 368

Chapter 9

Sinusoids and Phasors 369

9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8

Introduction 370 Sinusoids 371 Phasors 376 Phasor Relationships for Circuit Elements 385 Impedance and Admittance 387 † Kirchhoff’s Laws in the Frequency Domain 389 Impedance Combinations 390 † Applications 396 9.8.1 Phase-Shifters 9.8.2 AC Bridges

9.9

Summary

402

Review Questions 403 Problems 403 Comprehensive Problems 411

Chapter 10

299

Review Questions 300 Problems 301 Comprehensive Problems 311

Second-Order Circuits 313

10.1 10.2 10.3

Sinusoidal Steady-State Analysis 413

Introduction 414 Nodal Analysis 414 Mesh Analysis 417

ale29559_fm.qxd

07/28/2008

11:54 AM

Page ix

Contents

10.4 10.5 10.6 10.7 10.8 10.9

Superposition Theorem 421 Source Transformation 424 Thevenin and Norton Equivalent Circuits 426 Op Amp AC Circuits 431 AC Analysis Using PSpice 433 † Applications 437 10.9.1 Capacitance Multiplier 10.9.2 Oscillators

10.10 Summary

441

Review Questions 441 Problems 443

Chapter 11 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9

AC Power Analysis 457

Introduction 458 Instantaneous and Average Power 458 Maximum Average Power Transfer 464 Effective or RMS Value 467 Apparent Power and Power Factor 470 Complex Power 473 † Conservation of AC Power 477 Power Factor Correction 481 † Applications 483 11.9.1 Power Measurement 11.9.2 Electricity Consumption Cost

11.10 Summary

488

Review Questions 490 Problems 490 Comprehensive Problems 500

Chapter 12

12.11 Summary

Introduction 504 Balanced Three-Phase Voltages 505 Balanced Wye-Wye Connection 509 Balanced Wye-Delta Connection 512 Balanced Delta-Delta Connection 514 12.6 Balanced Delta-Wye Connection 516 12.7 Power in a Balanced System 519 12.8 †Unbalanced Three-Phase Systems 525 12.9 PSpice for Three-Phase Circuits 529 12.10 †Applications 534 12.10.1 Three-Phase Power Measurement 12.10.2 Residential Wiring

543

Review Questions 543 Problems 544 Comprehensive Problems 553

Chapter 13 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9

Magnetically Coupled Circuits 555

Introduction 556 Mutual Inductance 557 Energy in a Coupled Circuit 564 Linear Transformers 567 Ideal Transformers 573 Ideal Autotransformers 581 † Three-Phase Transformers 584 PSpice Analysis of Magnetically Coupled Circuits 586 † Applications 591 13.9.1 Transformer as an Isolation Device 13.9.2 Transformer as a Matching Device 13.9.3 Power Distribution

13.10 Summary

597

Review Questions 598 Problems 599 Comprehensive Problems 611

Chapter 14 14.1 14.2 14.3 14.4 14.5 14.6 14.7

14.8

Lowpass Filter Highpass Filter Bandpass Filter Bandstop Filter

Active Filters 642 14.8.1 14.8.2 14.8.3 14.8.4

14.9

Frequency Response 613

Introduction 614 Transfer Function 614 † The Decibel Scale 617 Bode Plots 619 Series Resonance 629 Parallel Resonance 634 Passive Filters 637 14.7.1 14.7.2 14.7.3 14.7.4

Three-Phase Circuits 503

12.1 12.2 12.3 12.4 12.5

ix

First-Order Lowpass Filter First-Order Highpass Filter Bandpass Filter Bandreject (or Notch) Filter

Scaling

648

14.9.1 Magnitude Scaling 14.9.2 Frequency Scaling 14.9.3 Magnitude and Frequency Scaling

14.10 Frequency Response Using PSpice 652 14.11 Computation Using MATLAB

655

ale29559_fm.qxd

07/28/2008

11:54 AM

Page x

Contents

x

14.12

†

Applications 657

17.3

14.12.1 Radio Receiver 14.12.2 Touch-Tone Telephone 14.12.3 Crossover Network

14.13 Summary

663

Review Questions 664 Problems 665 Comprehensive Problems 673

Symmetry Considerations 764 17.3.1 Even Symmetry 17.3.2 Odd Symmetry 17.3.3 Half-Wave Symmetry

17.4 17.5 17.6 17.7

Circuit Applications 774 Average Power and RMS Values 778 Exponential Fourier Series 781 Fourier Analysis with PSpice 787 17.7.1 Discrete Fourier Transform 17.7.2 Fast Fourier Transform

17.8

PART 3 Chapter 15 15.1 15.2 15.3 15.4

15.5 15.6 15.7

Advanced Circuit Analysis 674

†

Applications 793

17.8.1 Spectrum Analyzers 17.8.2 Filters

17.9

Summary

796

Review Questions 798 Problems 798 Comprehensive Problems 807

Introduction to the Laplace Transform 675

Introduction 676 Definition of the Laplace Transform 677 Properties of the Laplace Transform 679 The Inverse Laplace Transform 690

Chapter 18

15.4.1 Simple Poles 15.4.2 Repeated Poles 15.4.3 Complex Poles

18.1 18.2 18.3

The Convolution Integral 697 † Application to Integrodifferential Equations 705 Summary 708

18.4 18.5 18.6

Review Questions 708 Problems 709

18.7

Fourier Transform 809

Introduction 810 Definition of the Fourier Transform 810 Properties of the Fourier Transform 816 Circuit Applications 829 Parseval’s Theorem 832 Comparing the Fourier and Laplace Transforms 835 † Applications 836 18.7.1 Amplitude Modulation 18.7.2 Sampling

Chapter 16 16.1 16.2 16.3 16.4 16.5 16.6

Applications of the Laplace Transform 715

Introduction 716 Circuit Element Models 716 Circuit Analysis 722 Transfer Functions 726 State Variables 730 † Applications 737 16.6.1 Network Stability 16.6.2 Network Synthesis

16.7

Summary

745

Review Questions 746 Problems 747 Comprehensive Problems 754

18.8

17.1 17.2

The Fourier Series 755

Introduction 756 Trigonometric Fourier Series 756

839

Review Questions 840 Problems 841 Comprehensive Problems 847

Chapter 19 19.1 19.2 19.3 19.4 19.5 19.6 19.7 19.8
<...