Skip to content
CloverTexts Logo 🍀 CloverTexts Library

Fundamentals of Electric Circuits

← Back to Fundamentals of Electric Circuits Overview

Fundamentals of Electric Circuits

Charles K. Alexander

Department of Electrical and Computer Engineering Cleveland State University

Matthew N. O. Sadiku

Department of Electrical and Computer Engineering

Prairie View A&M University

FUNDAMENTALS OF ELECTRIC CIRCUITS, SIXTH EDITION

Published by McGraw-Hill Education, 2 Penn Plaza, New York, NY 10121. Copyright © 2017 by McGraw-Hill Education. All rights reserved. Printed in the United States of America. Previous editions © 2013, 2009, and 2007. 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 McGraw-Hill Education, 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 DOW/DOW 1 0 9 8 7 6 5

ISBN 978-0-07-802822-9 MHID 0-07-802822-1

Senior Vice President, Products & Markets: Kurt L. Strand Vice President, General Manager, Products & Markets: Marty Lange Vice President, Content Design & Delivery: Kimberly Meriwether David Managing Director: Thomas Timp Global Brand Manager: Raghu Srinivasan Director, Product Development: Rose Koos Product Developer: Vincent Bradshaw Marketing Manager: Nick McFadden Digital Product Analyst: Patrick Diller Associate Director of Digital Content: Amy Bumbaco, Ph.D. Director, Content Design & Delivery: Linda Avenarius Program Manager: Faye M. Herrig Content Project Managers: Melissa M. Leick, Tammy Juran, Sandra Schnee Buyer: Sandy Ludovissy Design: Studio Montage, Inc. Content Licensing Specialist: Lorraine Buczek Cover Image: Courtesy NASA/JPL - Caltech Compositor: MPS Limited Printer: R. R. Donnelley

All credits appearing on page or at the end of the book are considered to be an extension of the copyright page.

Library of Congress Cataloging-in-Publication Data

Alexander, Charles K., author.

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. — Sixth edition.

pages cm Includes index. ISBN 978-0-07-802822-9 (alk. paper) — ISBN 0-07-802822-1 (alk. paper) 1. Electric circuits. I. Sadiku, Matthew N. O., author. II. Title.

TK454.A452 2017 621.3815—dc23 2015035301

The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a website does not indicate an endorsement by the authors or McGraw-Hill Education, and McGraw-Hill Education does not guarantee the accuracy of the information presented at these sites.

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

Matthew and Chuck

This page intentionally left blank

Contents

Preface xi Acknowledgments xv About the Authors xxi

PART 1 DC Circuits 2 Chapter 1 Basic Concepts 3 1.1 Introduction 4 1.2 Systems of Units 5 1.3 Charge and Current 6 1.4 Voltage 9 1.5 Power and Energy 10 1.6 Circuit Elements 14 1.7 Applications 16 1.7.1 TV Picture Tube 1.7.2 Electricity Bills 1.8 Problem Solving 19 1.9 Summary 22 Review Questions 23 Problems 24 Comprehensive Problems 26

Chapter 2 Basic Laws 29

Problems 65

Comprehensive Problems 77

Chapter 3 Methods of Analysis 79

Chapter 4 Circuit Theorems 125

Chapter 5 Operational Amplifiers 173

5.3 Ideal Op Amp 178 5.4 Inverting Amplifier 179 5.5 Noninverting Amplifier 181 5.6 Summing Amplifier 183 5.7 Difference Amplifier 185 5.8 Cascaded Op Amp Circuits 189 5.9 Op Amp Circuit Analysis with PSpice 192 5.10 Applications 194 5.10.1 Digital-to-Analog Converter 5.10.2 Instrumentation Amplifiers 5.11 Summary 197 Review Questions 199 Problems 200 Comprehensive Problems 211

Chapter 6 Capacitors and Inductors 213

Chapter 7 First-Order Circuits 251

Chapter 8 Second-Order Circuits 311

PART 2 AC Circuits  366

Chapter 9 Sinusoids and Phasors 367

Chapter 10 Sinusoidal Steady-State Analysis 411

Chapter 11 AC Power Analysis 455

Chapter 12 Three-Phase Circuits 501

12.11 Summary 541 Review Questions 541 Problems 542 Comprehensive Problems 551

Chapter 13 Magnetically Coupled Circuits 553

Chapter 14 Frequency Response 611

PART 3 Advanced Circuit Analysis 672

Chapter 15 Introduction to the Laplace Transform 673

Chapter 16 Applications of the Laplace Transform 713

Chapter 17 The Fourier Series 757

Chapter 18 Fourier Transform 811

Chapter 19 Two-Port Networks 851

Contents ix

Index I-1

This page intentionally left blank

Preface

In keeping with our focus on space for covers for our book, we have chosen the NASA Voyager spacecraft for the sixth edition. The reason for this is that like any spacecraft there are many circuits that play criti cal roles in their functionality. The beginning of the Voyager 1 and 2 odyssey began on August 20, 1977, for Voyager 2 and on September 5, 1977, for Voyager 1. Both were launched from NASA’s Kennedy Space Center in Florida. The Voyager 1 was launched on a faster orbit so it eventually became the first man-made object to leave our solar system. There is some debate over whether it has actually left the solar system, but it certainly will at some point in time. Voyager 2 and two Pioneer spacecraft will also leave the solar system at some point in time.

Voyager 1 is still functioning and sending back data, a truly significant achievement for NASA engineers. The design processes that make the Voyager operate so reliably are based on the fundamentals discussed in this textbook. Finally, space is vast so that Voyager 1 will fly past other solar systems; the odds of actually coming into contact with something are so remote that it may virtually fly through the universe forever! For more about Voyager 1, go to NASA’s website: www.nasa.gov/.

Features

New to This Edition

We have added learning objectives to each chapter to reflect what we believe are the most important items to learn from each chapter. These should help you focus more carefully on what you should be learning.

There are more than 580 revised end-of-chapter problems, new endof-chapter problems, and revised practice problems. We continue to try and make our problems as practical as possible.

In addition, we have improved Connect for this edition by increasing the number of problems available substantially. Now, professors may select from more than a thousand problems as they build thier online homework assignments.

We have also built SmartBook for this edition. With SmartBook, stu dents get the same text as the print version, along with personalized tips on what to study next, thanks to SmartBook’s adaptive technology.

Retained from Previous Editions

A course in circuit analysis is perhaps the first exposure students have to electrical engineering. This is also a place where we can enhance some of the skills that they will later need as they learn how to design. An important part of this book is our 121 design a problem problems. These problems were developed to enhance skills that are an impor tant part of the design process. We know it is not possible to fully develop a student’s design skills in a fundamental course like circuits. To fully develop design skills a student needs a design experience

normally reserved for their senior year. This does not mean that some of those skills cannot be developed and exercised in a circuits course. The text already included open-ended questions that help students use creativity, which is an important part of learning how to design. We already have some questions that are open-ended but we desired to add much more into our text in this important area and have devel oped an approach to do just that. When we develop problems for the student to solve our goal is that in solving the problem the student learns more about the theory and the problem solving process. Why not have the students design problems like we do? That is exactly what we do in each chapter. Within the normal problem set, we have a set of problems where we ask the student to design a problem to help other students better understand an important concept. This has two very important results. The first will be a better understanding of the basic theory and the second will be the enhancement of some of the student’s basic design skills. We are making effective use of the principle of learning by teaching. Essentially we all learn better when we teach a subject. Designing effective problems is a key part of the teaching process. Students should also be encouraged to develop problems, when appropriate, which have nice numbers and do not necessarily overemphasize complicated mathematical manipulations.

A very important advantage to our textbook, we have a total of 2,481 Examples, Practice Problems, Review Questions, and End-of-Chapter Problems! Answers are provided for all practice problems and the odd numbered end-of-chapter problems.

The main objective of the sixth edition of this book remains the same as the previous editions—to present circuit analysis in a manner that is clearer, more interesting, and easier to understand than other cir cuit textbooks, and to assist the student in beginning to see the “fun” in engineering. This objective is achieved in the following ways:

• Chapter Openers and Summaries

Each chapter opens with a discussion about how to enhance skills which contribute to successful problem solving as well as success ful careers or a career-oriented talk on a subdiscipline of electrical engineering. This is followed by an introduction that links the chap ter with the previous chapters and states the chapter objectives. The chapter ends with a summary of key points and formulas.

• Problem-Solving Methodology

Chapter 1 introduces a six-step method for solving circuit problems which is used consistently throughout the book and media supple ments to promote best-practice problem-solving procedures.

• Student-Friendly Writing Style

All principles are presented in a lucid, logical, step-by-step man ner. As much as possible, we avoid wordiness and giving too much detail that could hide concepts and impede overall understanding of the material.

• Boxed Formulas and Key Terms

Important formulas are boxed as a means of helping students sort out what is essential from what is not. Also, to ensure that students clearly understand the key elements of the subject matter, key terms are defined and highlighted.

• Margin Notes

Marginal notes are used as a pedagogical aid. They serve multiple uses such as hints, cross-references, more exposition, warnings, reminders not to make some particular common mistakes, and prob lem-solving insights.

• Worked Examples

Thoroughly worked examples are liberally given at the end of ev ery section. The examples are regarded as a part of the text and are clearly explained without asking the reader to fill in missing steps. Thoroughly worked examples give students a good understanding of the solution process and the confidence to solve problems them selves. Some of the problems are solved in two or three different ways to facilitate a substantial comprehension of the subject mate rial as well as a comparison of different approaches.

• Practice Problems

To give students practice opportunity, each illustrative example is immediately followed by a practice problem with the answer. The student can follow the example step-by-step to aid in the solution of the practice problem without flipping pages or looking at the end of the book for answers. The practice problem is also intended to test a student’s understanding of the preceding example. It will reinforce their grasp of the material before the student can move on to the next section. Complete solutions to the practice problems are avail able to students on the website.

• Application Sections

The last section in each chapter is devoted to practical application aspects of the concepts covered in the chapter. The material covered in the chapter is applied to at least one or two practical problems or devices. This helps students see how the concepts are applied to real-life situations.

• Review Questions

Ten review questions in the form of multiple-choice objective items are provided at the end of each chapter with answers. The review questions 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 mas tered the chapter.

• Computer Tools

In recognition of the requirements by ABET ® on integrating computer tools, the use of PSpice, Multisim, MATLAB, KCIDE for Circuits, and developing design skills are encouraged in a studentfriendly manner. PSpice is covered early on in the text so that stu dents can become familiar and use it throughout the text. Tutorials on all of these are available on Connect. MATLAB is also introduced early in the book.

• Design a Problem Problems

Finally, design a problem problems are meant to help the student de velop skills that will be needed in the design process.

• Historical Tidbits

Historical sketches throughout the text provide profiles of important pioneers and events relevant to the study of electrical engineering.

• Early Op Amp Discussion

The operational amplifier (op amp) as a basic element is introduced early in the text.