9TH EDITION Introduction to Electric Circuits

1 9TH EDITIONI ntroduction toElectric CircuitsJames A. SvobodaClarkson UniversityRichard C. DorfUniversity of CaliforniaPUBLISHERDon FowleyEXECUTIVE EDITORDan SayreCONTENT MANAGERK evin HolmPRODUCTION EDITORTim LindnerEXECUTIVE MARKETING MANAGERC hris RuelMARKETING ASSISTANTM arissa CarrollDESIGN DIRECTORH arry NolanPRODUCT DESIGNERJ enny WelterEDITORIAL OPERATIONS MANAGERM elissa EdwardsEDITORIAL OPERATIONS ASSISTANTC ourtney WelshSENIOR DESIGNERM adelyn LesurePHOTO EDITORS heena GoldsteinSENIOR CONTENT EDITORW endy AshenbergEDITORIAL PROGRAM ASSISTANTJ essica KnechtCONTENT ASSISTANTH elen SeachristPRODUCTION MANAGEMENT SERVICESB ruce Hobart/Laserwords MaineCover Photos:#Jivko ; Alberto Pomares/Getty Images;# ;# book was set in 10/12 pt in Times New Roman by Laserwords Maine, and printed and bound by RRD Jefferson cover was printed by RRD Jefferson book is printed on acid-free paper.

2 1 Copyright#2014, 2010, 2006, 2004, 2001 John Wiley & Sons, Inc. All rights reserved. No part of this publication may bereproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying,recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act,without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee tothe Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, Requests to thePublisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., Ill River Street,Hoboken, NJ 07030-5774, (201) 748-6011, fax (201) 748-6008, copies are provided to qualified academics and professionals for review purposes only, for use in their courses duringthe next academic year.

3 These copies are licensed and may not be sold or transferred to a third party. Upon completion of thereview period, please return the evaluation copy to Wiley. Return instructions and a free of charge return shipping label areavailable Outside of the United States, please contact your local : 978-1-118-47750-2 BRV ISBN: 978-1-118-52106-9 Printed in the United States of America10987654321 The scientific nature of the ordinary manIs to go on out and do the best he can. John PrineBut, Captain, I cannot change the laws of physics. Lt. Cmdr. Montogomery Scott (Scotty), USSE nterpriseDedicated to our grandchildren:Ian Christopher Boilard, Kyle Everett Schafer, and Graham Henry SchaferandHeather Lynn Svoboda, James Hugh Svoboda, Jacob Arthur Leis,Maxwell Andrew Leis, and Jack Mandlin SvobodaAbouttheAuthorsJames A. Svobodais an associate professor of electrical and computer engineer-ing at Clarkson University, where he teaches courses on topics such as Circuits ,electronics, and computer programming.

4 He earned a PhD in electrical engineeringfrom the University of Wisconsin at Madison, an MS from the University of Colorado,and a BS from General Motors Circuits is one of Professor Svoboda s favorite courses. He hastaught this course to 6,500 undergraduates at Clarkson University over the past 35years. In 1986, he received Clarkson University s Distinguished Teaching Svoboda has written several research papers describing the advantagesof using nullors to model Electric Circuits for computer analysis. He is interested in theway technology affects engineering education and has developed several softwarepackages for use in Sophomore C. Dorf, professor of electrical and computer engineeringat the University of California, Davis, teaches graduate and under-graduate courses in electrical engineering in thefields of Circuits andcontrol systems.

5 He earned a PhD in electrical engineering from Naval Postgraduate School, an MS from the University ofColorado, and a BS from Clarkson University. Highly concernedwith the discipline of electrical engineering and its wide value tosocial and economic needs, he has written and lectured internationallyon the contributions and advances in electrical Dorf has extensive experience with education andindustry and is professionally active in thefields of robotics, automa-tion, Electric Circuits , and communications. He has served as a visitingprofessor at the University of Edinburgh, Scotland, the MassachusettsInstitute of Technology, Stanford University, and the University ofCalifornia at Fellow of the Institute of Electrical and Electronic Engineers and the American Society forEngineering Education, Dr. Dorf is widely known to the profession for hisModern Control Systems,twelfth EDITION (Pearson, 2011) andThe International Encyclopedia of Robotics(Wiley, 1988).

6 Dr. Dorf is also the coauthor ofCircuits, Devices and Systems(with Ralph Smith),fifth EDITION (Wiley, 1992). Dr. Dorf edited the widely usedElectrical Engineering handbook , third EDITION (CRCP ress and IEEE press), published in 2011. His latest work is Technology Ventures, fourth EDITION (McGraw-Hill 2013).ixPrefaceThe central theme ofIntroduction to Electric Circuitsis the concept that Electric Circuits are partof the basic fabric of modern technology. Given this theme, we endeavor to show how theanalysis and design of Electric Circuits are inseparably intertwined with the ability of the engineerto design complex electronic, communication, computer, and control systems as well as and OrganizationThis book is designed for a one- to three-term course in Electric Circuits or linear circuit analysis and isstructured for maximumflexibility.

7 Theflowchart in Figure 1 demonstrates alternative chapterorganizations that can accommodate different course outlines without disrupting presentation is geared to readers who are being exposed to the basic concepts of electriccircuits for thefirst time, and the scope of the work is broad. Students should come to the course with thebasic knowledge of differential and integral book endeavors to prepare the reader to solve realistic problems involving Electric , Circuits are shown to be the results of real inventions and the answers to real needs in industry, theoffice, and the home. Although the tools of Electric circuit analysis may be partially abstract, electriccircuits are the building blocks of modern society. The analysis and design of Electric Circuits are criticalskills for all s New in the 9th EditionRevisions to Improve ClarityChapter 10, covering AC Circuits , has been largely rewritten to improve clarity of addition, revisions have been made through the text to improve clarity.

8 Sometimes these revisionsare small, involving sentences or paragraphs. Other larger revisions involved pages or even entiresections. Often these revisions involve examples. Consequently, the 9th EDITION contains 36 ProblemsThe 9th EDITION contains 180 new problems, bringing the total number of problems to more than 1, EDITION uses a variety of problem types and they range in difficulty from simple to challenging,including: Straightforward analysis problems. Analysis of complicated Circuits . Simple design problems. (For example, given a circuit and the specified response, determine therequiredRLCvalues.) Compare and contrast, multipart problems that draw attention to similarities or differences betweentwo situations. MATLAB and PSpice problems. Design problems. (Given some specifications, devise a circuit that satisfies those specifications.)

9 How Can We Check .. ? (Verify that a solution is indeed correct.)xiFeatures Retained from Previous EditionsIntroductionEach chapter begins with an Introduction that motivates consideration of the material of that this book is oriented toward providing expertise in problem solving, we have included morethan 260 illustrative examples. Also, each example has a title that directs the student to exactly what isbeing illustrated in that particular methods of solving problems are incorporated into select examples. These cases showstudents that multiple methods can be used to derive similar solutions or, in some cases, that multiplesolutions can be correct. This helps students build the critical thinking skills necessary to discern thebest choice between multiple attention has been given to using PSpice and MATLAB to solve Circuits problems.

10 Twoappendices, one introducing PSpice and the other introducing MATLAB, briefly describe thecapabilities of the programs and illustrate the steps needed to get started using them. Next, PSpiceA1 ELECTRICCIRCUITVARIABLESC olorCodeMatrices,Determinants2 CIRCUITELEMENTS4 METHODS OFANALYSIS OFRESISTIVECIRCUITS3 RESISTIVECIRCUITSEB, C, DComplexNumbers9 THE COMPLETERESPONSE OFCIRCUITS WITHTWO ENERGYSTORAGE ELEMENTS11AC STEADY-STATEPOWER12 THREE-PHASECIRCUITS10 SINUSOIDALSTEADY-STATEANALYSISFIGURE 1 Flow chart showing alternative paths through the topics in this MATLAB are used throughout the text to solve various circuit analysis and design problems. Forexample, PSpice is used in Chapter 5 tofind a Th evenin equivalent circuit and in Chapter 15 to representcircuit inputs and outputs as Fourier series. MATLAB is frequently used to obtain plots of circuit inputsand outputs that help us to see what our equations are telling us.