Tài liệu 1385083

  • Số trang: 766 |
  • Loại file: PDF |
  • Lượt xem: 707 |
  • Lượt tải: 0

Tham gia: 28/01/2015

Mô tả:

January 11, 2008 19:13 fm Sheet number 1 Page number i magenta black FUNDAMENTALS OF ELECTRICAL ENGINEERING First Edition Giorgio Rizzoni The Ohio State University January 11, 2008 19:13 fm Sheet number 2 Page number ii magenta black FUNDAMENTALS OF ELECTRICAL ENGINEERING 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. 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 978–0–07–338037–7 MHID 0–07–338037–7 Global Publisher: Raghothaman Srinivasan Director of Development: Kristine Tibbetts Developmental Editor: Darlene M. Schueller Senior Project Manager: Sheila M. Frank Lead Production Supervisor: Sandy Ludovissy Lead Media Project Manager: Judi David Designer: Laurie B. Janssen Cover/Interior Designer: Ron Bissell (USE) Cover Image: Kevin Ponziani, Buckeye Bullet 2 team member and ECE student at Ohio State, Getty Images RF Lead Photo Research Coordinator: Carrie K. Burger Compositor: Newgen Typeface: 10/12 Times Roman Printer: Von Hoffmann Press Part Openers: 1,2: © PhotoDisc RF/Getty; 3: Courtesy Ford Motor Company. Library of Congress Cataloging-in-Publication Data Rizzoni, Giorgio. Fundamentals of electrical engineering / Giorgio Rizzoni. – 1st ed. p. cm. Includes index. ISBN 978–0–07–338037–7 — ISBN 0–07–338037–7 (hard copy : alk. paper) 1. Electric engineering. I. Title. TK146.R4725 621.3–dc22 2009 2008000852 In memoria di mamma www.mhhe.com January 11, 2008 19:13 fm Sheet number 3 Page number iii magenta black About the Author iorgio Rizzoni, The Ford Motor Company Chair of ElectroMechanical Systems, received the B.S., M.S., and Ph.D. degrees, all in electrical engineering, from the University of Michigan. He is currently a professor of mechanical and electrical engineering at The Ohio State University, where he teaches undergraduate courses in system dynamics, measurements, and mechatronics and graduate courses in automotive power train modeling and control, hybrid vehicle modeling and control, and system fault diagnosis. Dr. Rizzoni has been involved in the development of innovative curricula and educational programs throughout his career. At the University of Michigan, he developed a new laboratory and curriculum for the circuits and electronics engineering service course for non–electrical engineering majors. At Ohio State, he has been involved in the development of undergraduate and graduate curricula in mechatronic systems with funding provided, in part, by the National Science Foundation through an interdisciplinary curriculum development grant. The present book has been profoundly influenced by this curriculum development. Professor Rizzoni has contributed to the development of a graduate curriculum in these areas, served as the director of U.S. Department of Energy Graduate Automotive Technology Education Center for Hybrid Drivetrains and Control Systems, and is currently serving as Director of the new U.S. Department of Energy Graduate Automotive Technology Education Center for Advanced Propulsion Systems. He has developed various new courses in systems dynamics, mechatronics, fault diagnosis, powertrain dynamics and hybrid-electric vehicles. Since 1999, Dr. Rizzoni has served as director of the Ohio State University Center for Automotive Research, an interdisciplinary research center serving the U.S. government and the automotive industry worldwide. The center conducts research in areas related to vehicle safety, energy efficiency, environmental impact, and passenger comfort. Dr. Rizzoni has published more than 200 papers in peer-reviewed journals and conference proceedings, and he has received a number of recognitions, including a 1991 NSF Presidential Young Investigator Award. Dr. Rizzoni is a Fellow of IEEE, a Fellow of SAE, and a member of ASME and ASEE; he has served as an Associate Editor of the ASME Journal of Dynamic Systems, Measurements, and Control (1993 to 1998) and of the IEEE Transactions on Vehicular Technology (1988 to 1998). He has also served as Guest Editor of Special Issues of the IEEE Transactions on Control System Technology, of the IEEE Control Systems Magazine, and of Control Engineering Practice; Dr. Rizzoni is a past Chair of the ASME Dynamic Systems and Control Division, and has served as Chair of the Technical Committee on Automotive Control for the International Federation of Automatic Control (IFAC). Giorgio Rizzoni is the Ohio State University SAE student branch faculty adviser, and has led teams of electrical and mechanical engineering students through the development of an electric vehicle that established various land speed records in 2003 and 2004. He has more recently led a team of students to the development of a hydrogen fuel cell electric land speed record vehicle, the Buckeye Bullet 2 (see cover and inside coverpage). He is also coadviser of the Ohio State University FutureTruck and Challenge-X hybrid-electric vehicle competition teams sponsored by the U.S. Department of Energy, and by General Motors and Ford. http://car.osu.edu iii January 11, 2008 19:13 fm Sheet number 4 Page number iv magenta black Contents Preface vi Chapter 1 Introduction to Electrical Engineering 1 1.1 Electrical Engineering 2 1.2 Fundamentals of Engineering Exam Review 4 1.3 System of Units 5 1.4 Special Features of This Book 5 PART I CIRCUITS 8 Chapter 2 Fundamentals of Electric Circuits 9 2.1 Definitions 10 2.2 Charge, Current, and Kirchhoff’s Current Law 14 2.3 Voltage and Kirchhoff’s Voltage Law 20 2.4 Electric Power and Sign Convention 24 2.5 Circuit Elements and Their i-v Characteristics 28 2.6 Resistance and Ohm’s Law 29 2.7 Practical Voltage and Current Sources 44 2.8 Measuring Devices 45 Chapter 3 Resistive Network Analysis 63 3.1 Network Analysis 64 3.2 The Node Voltage Method 65 3.3 The Mesh Current Method 75 3.4 Node and Mesh Analysis With Controlled 3.5 3.6 3.7 3.8 Sources 82 The Principle of Superposition 87 One-Port Networks and Equivalent Circuits 90 Maximum Power Transfer 106 Nonlinear Circuit Elements 110 Chapter 4 AC Network Analysis 129 4.1 Energy Storage (Dynamic) Circuit 4.2 4.3 4.4 iv Elements 130 Time-Dependent Signal Sources 145 Solution of Circuits Containing Energy Storage Elements (Dynamic Circuits) 150 Phasor Solution of Circuits With Sinusoidal Excitation 153 Chapter 5 Transient Analysis 177 5.1 Transient Analysis 178 5.2 Writing Differential Equations for Circuits Containing Inductors and Capacitors 179 5.3 DC Steady-State Solution of 5.4 5.5 Circuits Containing Inductors and Capacitors—Initial and Final Conditions 184 Transient Response of First-Order Circuits 190 Transient Response of Second-Order Circuits 209 Chapter 6 Frequency Response and System Concepts 243 6.1 Sinusoidal Frequency Response 244 6.2 Filters 249 6.3 Bode Plots 265 Chapter 7 AC Power 279 7.1 Power in AC Circuits 280 7.2 Complex Power 287 7.3 Transformers 303 7.4 Three-Phase Power 313 7.5 Residential Wiring; Grounding and Safety 321 7.6 Generation and Distribution of AC Power 325 PART II ELECTRONICS 340 Chapter 8 Operational Amplifiers 341 8.1 Ideal Amplifiers 342 8.2 The Operational Amplifier 344 8.3 Active Filters 366 8.4 Integrator and Differentiator Circuits 372 8.5 Physical Limitations of Operational Amplifiers 374 Chapter 9 Semiconductors and Diodes 407 9.1 Electrical Conduction in Semiconductor Devices 408 9.2 The pn Junction and the Semiconductor Diode 410 January 11, 2008 19:13 fm Sheet number 5 Page number v magenta black Contents 9.3 Circuit Models for the Semiconductor 9.4 9.5 Diode 413 Rectifier Circuits 431 DC Power Supplies, Zener Diodes, and Voltage Regulation 436 Chapter 10 Bipolar Junction Transistors: Operation, Circuit Models, and Applications 453 10.1 Transistors as Amplifiers and Switches 454 10.2 Operation of the Bipolar Junction Transistor 456 10.3 BJT Large-Signal Model 462 10.4 Selecting an Operating Point for a BJT 470 10.5 BJT Switches and Gates 478 Chapter 11 Field-Effect Transistors: Operation, Circuit Models, and Applications 491 11.1 Classification of Field-Effect Transistors 492 11.2 Overview of Enhancement-Mode 11.3 11.4 11.5 Mosfets 492 Biasing Mosfet Circuits 497 Mosfet Large-Signal Amplifiers 503 Mosfet Switches 510 Chapter 12 Digital Logic Circuits 521 12.1 Analog and Digital Signals 522 12.2 The Binary Number System 524 12.3 Boolean Algebra 531 12.4 Karnaugh Maps and Logic Design 544 12.5 Combinational Logic Modules 557 12.6 Sequential Logic Modules 562 ∗ PART III v ELECTROMECHANICS 586 Chapter 13 Principles of Electromechanics 587 13.1 Electricity and Magnetism 588 13.2 Magnetic Circuits 598 13.3 Magnetic Materials and B-H Curves 609 13.4 Transformers 611 13.5 Electromechanical Energy Conversion 615 Chapter 14 Introduction to Electric Machines 645 14.1 Rotating Electric Machines 646 14.2 Direct-Current Machines 658 14.3 Direct-Current Generators 664 14.4 Direct-Current Motors 668 14.5 AC Machines 681 14.6 The Alternator (Synchronous Generator) 683 14.7 The Synchronous Motor 685 14.8 The Induction Motor 690 Appendix A Linear Algebra and Complex Numbers∗ Appendix B The Laplace Transform∗ Appendix C Fundamentals of Engineering (FE) Examination∗ Appendix D Answers to Selected Problems 710 Index 720 Appendixes A, B, and C are available online at www.mhhe.com/rizzoni January 11, 2008 19:13 fm Sheet number 6 Page number vi magenta black Preface he pervasive presence of electronic devices and instrumentation in all aspects of engineering design and analysis is one of the manifestations of the electronic revolution that has characterized the second half of the 20th century. Every aspect of engineering practice, and even of everyday life, has been affected in some way or another by electrical and electronic devices and instruments. Computers are perhaps the most obvious manifestations of this presence. However, many other areas of electrical engineering are also important to the practicing engineer, from mechanical and industrial engineering, to chemical, nuclear, and materials engineering, to the aerospace and astronautical disciplines, to civil and the emerging field of biomedical engineering. Engineers today must be able to communicate effectively within the interdisciplinary teams in which they work. OBJECTIVES Engineering education and engineering professional practice have seen some rather profound changes in the past decade. The integration of electronics and computer technologies in all engineering academic disciplines and the emergence of digital electronics and microcomputers as a central element of many engineering products and processes have become a common theme since the conception of this book. The principal objective of the book is to present the principles of electrical, electronic, and electromechanical engineering to an audience composed of non–electrical engineering majors, and ranging from sophomore students in their first required introductory electrical engineering course, to seniors, to first-year graduate students enrolled in more specialized courses in electronics, electromechanics, and mechatronics. A second objective is to present these principles by focusing on the important results and applications and presenting the students with the most appropriate analytical and computational tools to solve a variety of practical problems. Finally, a third objective of the book is to illustrate, by way of concrete, fully worked examples, a number of relevant applications of electrical engineering principles. These examples are drawn from the author’s industrial research experience and from ideas contributed by practicing engineers and industrial partners. ORGANIZATION AND CONTENT The book is divided into three parts, devoted to circuits, electronics, and electromechanics. Part I: Circuits The first part of this book presents a basic introduction to circuit analysis (Chapters 2 through 7). The material includes over 440 homework problems. Part: II Electronics Part II, on electronics (Chapters 8 through 12), contains a chapter on operational amplifiers, one on diodes, two chapters on transistors—one each on BJTs and FETs, and one on digital logic circuits. The material contained in this section is focused on basic applications of these concepts. The chapters include 320 homework problems. Part III: Electromechanics Part III, on electromechanics (Chapters 13 and 14), includes basic material on electromechanical transducers and the basic operation of DC and AC machines. The two chapters include 126 homework problems. vi January 11, 2008 19:13 fm Sheet number 7 Page number vii magenta black Preface vii FEATURES Pedagogy This edition contains the following pedagogical features. • • • • • • Learning Objectives offer an overview of key chapter ideas. Each chapter opens with a list of major objectives, and throughout the chapter the learning objective icon indicates targeted references to each objective. Focus on Methodology sections summarize important methods and procedures for the solution of common problems and assist the student in developing a methodical approach to problem solving. Clearly Illustrated Examples illustrate relevant applications of electrical engineering principles. The examples are fully integrated with the “Focus on Methodology” material, and each one is organized according to a prescribed set of logical steps. Check Your Understanding exercises follow each example in the text and allow students to confirm their mastery of concepts. Make the Connection sidebars present analogies to students to help them see the connection of electrical engineering concepts to other engineering disciplines. Find It on the Web links included throughout the book give students the opportunity to further explore practical engineering applications of the devices and systems that are described in the text. Supplements The book includes a wealth of supplements available in electronic form. These include • A website accompanies this text to provide students and instructors with additional resources for teaching and learning. You can find this site at www.mhhe.com/rizzoni. Resources on this site include For Students: • • Device Data Sheets Learning Objectives For Instructors: • • PowerPoint presentation slides of important figures from the text Instructor’s Solutions Manual with complete solutions (for instructors only) For Instructors and Students: • Find It on the Web links, which give students the opportunity to explore, in greater depth, practical engineering applications of the devices and systems that are described in the text. In addition, several links to tutorial sites extend the boundaries of the text to recent research developments, late-breaking science and technology news, learning resources, and study guides to help you in your studies and research. January 11, 2008 19:13 viii fm Sheet number 8 Page number viii magenta black Preface ACKNOWLEDGMENTS This edition of the book requires a special acknowledgment for the effort put forth by my friend Tom Hartley of the University of Akron, who has become a mentor, coach, and inspiration for me throughout this project. Professor Hartley, who is an extraordinary teacher and a devoted user of this book, has been closely involved in the development of this edition by suggesting topics for new examples and exercises, creating new homework problems, providing advice and coaching through all of the revisions, and sometimes just by lifting my spirits. I look forward to many more years of such collaborations. This book has been critically reviewed by the following people. • Hussain M. Al-Rizzo, University of Arkansas-Little Rock • Lisa Anneberg, Lawrence Technological University • Glen Archer, Michigan Tech University • Sohrab Asgarpoor, University of Nebraska-Lincoln • Satish Chandra, Kansas State University • Ezz I. El-Masry, Dalhousie University • Alexander Ganago, University of Michigan • Riadh W. Y. Habash, University of Ottawa • Michael Hamid, University of South Alabama • Vincent G. Harris, Northeastern University • Charles Hulme, U.S. Naval Academy • Jim Kearns, York College of Pennsylvania • Moncef Krarti, University of Colorado at Boulder • Dennis F. Lovely, University of New Brunswick • Gary Perks, Cal Poly University, San Luis Obispo • Michael P. Polis, Oakland University • Raveendra K. Rao, University of Western Ontario • Angela Rasmussen, University of Utah • James R. Rowland, University of Kansas • Ceeyavash (Jeff ) Salehi, Southern Utah University • Mulukutla S. Sarma, Northeastern University • Hesham Shaalan, U.S. Merchant Marine Academy • Rony Shahidain, Kentucky State University • Shahram Shahbazpanahi, University of Ontario Institute of Technology • Constantinos Vassiliadis, Ohio University-Athens • Belinda B. Wang, University of Toronto • Ken Warfield, Shawnee State University • Sean Washburn, University of North Carolina at Chapel Hill • Thomas Yang, Embry-Riddle Aeronautical University • Mohamed Z. Youssef, Queen’s University The author is also grateful to Professor Robert Veillette of the University of Akron for his many useful comments and suggestions. Book prefaces have a way of marking the passage of time. When the first edition of Principles and Applications of Electrical Engineering was published, the birth of our first child, Alex, was nearing. Each of the following two editions was similarly accompanied by the births of Maria and Michael. Now that we have successfully reached the fifth edition of Principles and Applications and the new first edition of this book (but only the third child) I am observing that Alex is beginning to understand some of the principles exposed in this book through his passion for the FIRST Lego League and the Lego Mindstorms robots. Through the years, our family continues to be the center of my life, and I am grateful to Kathryn, Alessandro, Maria, and Michael for all their love. January 11, 2008 19:13 fm Sheet number 9 Page number ix G U I D E D TO U R magenta black January 11, 2008 19:13 x Preface fm Sheet number 10 Page number x magenta black January 11, 2008 15:36 Chap01 C H Sheet number 1 Page number 1 A P T E magenta black R 1 INTRODUCTION TO ELECTRICAL ENGINEERING he aim of this chapter is to introduce electrical engineering. The chapter is organized to provide the newcomer with a view of the different specialties making up electrical engineering and to place the intent and organization of the book into perspective. Perhaps the first question that surfaces in the mind of the student approaching the subject is, Why electrical engineering? Since this book is directed at a readership having a mix of engineering backgrounds (including electrical engineering), the question is well justified and deserves some discussion. The chapter begins by defining the various branches of electrical engineering, showing some of the interactions among them, and illustrating by means of a practical example how electrical engineering is intimately connected to many other engineering disciplines. Section 1.2 introduces the Engineer-in-Training (EIT) national examination. In Section 1.3 the fundamental physical quantities and the system of units are defined, to set the stage for the chapters that follow. Finally, in Section 1.4 the organization of the book is discussed, to give the student, as well as the teacher, a sense of continuity in the development of the different subjects covered in Chapters 2 through 14. 1 January 11, 2008 15:36 2 Chapter 1 Table 1.1 Electrical engineering disciplines 1.1 Circuit analysis Electromagnetics Solid-state electronics Electric machines Electric power systems Digital logic circuits Computer systems Communication systems Electro-optics Instrumentation systems Control systems Chap01 Sheet number 2 Page number 2 magenta black Introduction to Electrical Engineering ELECTRICAL ENGINEERING The typical curriculum of an undergraduate electrical engineering student includes the subjects listed in Table 1.1. Although the distinction between some of these subjects is not always clear-cut, the table is sufficiently representative to serve our purposes. Figure 1.1 illustrates a possible interconnection between the disciplines of Table 1.1. The aim of this book is to introduce the non-electrical engineering student to those aspects of electrical engineering that are likely to be most relevant to his or her professional career. Virtually all the topics of Table 1.1 will be touched on in the book, with varying degrees of emphasis. Example 1.1 illustrates the pervasive presence of electrical, electronic, and electromechanical devices and systems in a very common application: the automobile. As you read through the examples, it will be instructive to refer to Figure 1.1 and Table 1.1. Engineering applications Power systems Mathematical foundations Electric machinery Physical foundations Network theory Analog electronics Electromagnetics Logic theory Digital electronics Solid-state physics System theory Computer systems Optics Control systems Communication systems Instrumentation systems Figure 1.1 Electrical engineering disciplines January 11, 2008 15:36 Chap01 Sheet number 3 Page number 3 Chapter 1 magenta black Introduction to Electrical Engineering EXAMPLE 1.1 Electrical Systems in a Passenger Automobile A familiar example illustrates how the seemingly disparate specialties of electrical engineering actually interact to permit the operation of a very familiar engineering system: the automobile. Figure 1.2 presents a view of electrical engineering systems in a modern automobile. Even in older vehicles, the electrical system—in effect, an electric circuit—plays a very important part in the overall operation. (Chapters 2 and 3 describe the basics of electric circuits.) An inductor coil generates a sufficiently high voltage to allow a spark to form across the spark plug gap and to ignite the air-fuel mixture; the coil is supplied by a DC voltage provided by a lead-acid battery. (Ignition circuits are studied in some detail in Chapter 5.) In addition to providing the energy for the ignition circuits, the battery supplies power to many other electrical components, the most obvious of which are the lights, the windshield wipers, and the radio. Electric power (Chapter 7) is carried from the battery to all these components by means of a wire harness, which constitutes a rather elaborate electric circuit (see Figure 2.12 for a closer look). In recent years, the conventional electric ignition system has been supplanted by electronic ignition; that is, solid-state electronic devices called transistors have replaced the traditional breaker points. The advantage of transistorized ignition systems over the conventional mechanical ones is their greater reliability, ease of control, and life span (mechanical breaker points are subject to wear). You will study transistors and other electronic devices in Chapters 8, 9, and 10. Other electrical engineering disciplines are fairly obvious in the automobile. The on-board radio receives electromagnetic waves by means of the antenna, and decodes the communication signals to reproduce sounds and speech of remote origin; other common communication systems that exploit electromagnetics are CB radios and the ever more common cellular phones. But this is not all! The battery is, in effect, a self-contained 12-VDC electric power system, providing the energy for all the aforementioned functions. In order for the battery to have a useful lifetime, a charging system, composed of an alternator and of power electronic devices, is present in every automobile. Electric power systems are covered in Chapter 7 and power electronic devices in Chapter 10. The alternator is an electric machine, as are the motors that drive the power mirrors, power windows, power seats, and other convenience features found in luxury cars. Incidentally, the loudspeakers are also electric machines! All these devices are described in Chapters 13 and 14. The list does not end here, though. In fact, some of the more interesting applications of electrical engineering to the automobile have not been discussed yet. Consider computer systems. Digital circuits are covered in Chapter 12. You are certainly aware that in the last two Convenience Climate control Ergonomics (seats, steering wheel, mirrors) Navigation Audio/video/ Internet / Wireless communications Propulsion Engine/transmission Integrated starter/alternator Electric traction 42-V system Battery management Traction control Safety Air bags and restraints Collision warning Security systems Ride and handling Active/semiactive suspension Antilock brakes Electric power steering Tire pressure control Four-wheel steering Stability control Figure 1.2 Electrical engineering systems in the automobile 3 January 11, 2008 15:36 4 Chapter 1 Chap01 Sheet number 4 Page number 4 magenta black Introduction to Electrical Engineering decades, environmental concerns related to exhaust emissions from automobiles have led to the introduction of sophisticated engine emission control systems. The heart of such control systems is a type of computer called a microprocessor. The microprocessor receives signals from devices (called sensors) that measure relevant variables—such as the engine speed, the concentration of oxygen in the exhaust gases, the position of the throttle valve (i.e., the driver’s demand for engine power), and the amount of air aspirated by the engine—and subsequently computes the optimal amount of fuel and the correct timing of the spark to result in the cleanest combustion possible under the circumstances. As the presence of computers on board becomes more pervasive—in areas such as antilock braking, electronically controlled suspensions, fourwheel steering systems, and electronic cruise control—communications among the various on-board computers will have to occur at faster and faster rates. Someday in the not-so-distant future, these communications may occur over a fiber-optic network, and electro-optics will replace the conventional wire harness. Note that electro-optics is already present in some of the more advanced displays that are part of an automotive instrumentation system. Finally, today’s vehicles also benefit from the significant advances made in communication systems. Vehicle navigation systems can include Global Positioning System, or GPS, technology, as well as a variety of communications and networking technologies, such as wireless interfaces (e.g., based on the “Bluetooth” standard) and satellite radio and driver assistance systems, such as the GM “OnStar” system. 1.2 FUNDAMENTALS OF ENGINEERING EXAM REVIEW To become a professional engineer it is necessary to satisfy four requirements. The first is the completion of a B.S. degree in engineering from an accredited college or university (although it is theoretically possible to be registered without having completed a degree). The second is the successful completion of the Fundamentals of Engineering (FE) Examination. This is an eight-hour exam that covers general undergraduate engineering education. The third requirement is two to four years of engineering experience after passing the FE exam. Finally, the fourth requirement is successful completion of the Principles and Practice of Engineering or Professional Engineer (PE) Examination. The FE exam is a two-part national examination, administered by the National Council of Examiners for Engineers and Surveyors (NCEES) and given twice a year (in April and October). The exam is divided into two four-hour sessions, consisting of 120 questions in the four-hour morning session, and 60 questions in the four-hour afternoon session. The morning session covers general background in 12 different areas, one of which is Electricity and Magnetism. The afternoon session requires the examinee to choose among seven modules—Chemical, Civil, Electrical, Environmental, Industrial, Mechanical, and Other/General engineering. One of the aims of this book is to assist you in preparing for the Electricity and Magnetism part of the morning session. This part of the examination consists of approximately 9 percent of the morning session, and covers the following topics: A. Charge, energy, current, voltage, power. B. Work done in moving a charge in an electric field (relationship between voltage and work). C. Force between charges. D. Current and voltage laws (Kirchhoff, Ohm). E. Equivalent circuits (series, parallel). January 11, 2008 15:36 Chap01 Sheet number 5 Page number 5 Chapter 1 magenta black Introduction to Electrical Engineering F. Capacitance and inductance. G. Reactance and impedance, susceptance and admittance. H. AC circuits. I. Basic complex algebra. Appendix C (available online) contains review of the electrical circuits portion of the FE examination, including references to the relevant material in the book. In addition, Appendix C also contains a collection of sample problems—some including a full explanation of the solution, some with answers supplied separately. This material has been derived from the author’s experience in co-teaching the FE exam preparation course offered to Ohio State University seniors. 1.3 SYSTEM OF UNITS This book employs the International System of Units (also called SI, from the French Système I nternational des Unités). SI units are commonly adhered to by virtually all engineering professional societies. This section summarizes SI units and will serve as a useful reference in reading the book. SI units are based on six fundamental quantities, listed in Table 1.2. All other units may be derived in terms of the fundamental units of Table 1.2. Since, in practice, one often needs to describe quantities that occur in large multiples or small fractions of a unit, standard prefixes are used to denote powers of 10 of SI (and derived) units. These prefixes are listed in Table 1.3. Note that, in general, engineering units are expressed in powers of 10 that are multiples of 3. For example, 10−4 s would be referred to as 100 × 10−6 s, or 100 μs (or, less frequently, 0.1 ms). Table 1.2 SI units 1.4 Table 1.3 Standard prefixes Quantity Unit Symbol Prefix Symbol Power Length Mass Time Electric current Temperature Luminous intensity Meter Kilogram Second Ampere Kelvin Candela m kg s A K cd atto femto pico nano micro milli centi deci deka kilo mega giga tera a f p n μ m c d da k M G T 10−18 10−15 10−12 10−9 10−6 10−3 10−2 10−1 10 103 106 109 1012 SPECIAL FEATURES OF THIS BOOK This book includes a number of special features designed to make learning easier and to allow students to explore the subject matter of the book in greater depth, if so desired, through the use of computer-aided tools and the Internet. The principal features of the book are described on the next two pages. 5 January 11, 2008 15:36 6 Chapter 1 Chap01 Sheet number 6 Page number 6 magenta black Introduction to Electrical Engineering ➲ Learning Objectives 1. 2. 3. The principal learning objectives are clearly identified at the beginning of each chapter. The symbol ➲ is used to identify definitions and derivations critical to the accomplishment of a specific learning objective. Each example is similarly marked. EXAMPLES The examples in the book have also been set aside from the main text, so that they can be easily identified. All examples are solved by following the same basic methodology: A clear and simple problem statement is given, followed by a solution. The solution consists of several parts: All known quantities in the problem are summarized, and the problem statement is translated into a specific objective (e.g., “Find the equivalent resistance R”). Next, the given data and assumptions are listed, and finally the analysis is presented. The analysis method is based on the following principle: All problems are solved symbolically first, to obtain more general solutions that may guide the student in solving homework problems; the numerical solution is provided at the very end of the analysis. Each problem closes with comments summarizing the findings and tying the example to other sections of the book. The solution methodology used in this book can be used as a general guide to problemsolving techniques well beyond the material taught in the introductory electrical engineering courses. The examples in this book are intended to help you develop sound problem-solving habits for the remainder of your engineering career. CHECK YOUR UNDERSTANDING Each example is accompanied by at least one drill exercise. Answer: The answer is provided right below the exercise. MAKE THE CONNECTION This feature is devoted to helping the student make the connection between electrical engineering and other engineering disciplines. Analogies to other fields of engineering will be found in nearly every chapter. F O C U S O N M ET H O D O L O GY Each chapter, especially the early ones, includes “boxes” titled “Focus on Methodology.” The content of these boxes (which are set aside from the main text) summarizes important methods and procedures for the solution of common problems. They usually consist of step-by-step instructions, and are designed to assist you in methodically solving problems. January 11, 2008 15:36 Chap01 Sheet number 7 Page number 7 Chapter 1 magenta black Introduction to Electrical Engineering 7 Find It on the Web! The use of the Internet as a resource for knowledge and information is becoming increasingly common. In recognition of this fact, website references have been included in this book to give you a starting point in the exploration of the world of electrical engineering. Typical web references give you information on electrical engineering companies, products, and methods. Some of the sites contain tutorial material that may supplement the book’s contents. Website The list of features would not be complete without a reference to the book’s website: www.mhhe.com/rizzoni. Create a bookmark for this site now! The site is designed to provide up-to-date additions, examples, errata, and other important information. HOMEWORK PROBLEMS 1.1 List five applications of electric motors in the common household. 1.2 By analogy with the discussion of electrical systems in the automobile, list examples of applications of the electrical engineering disciplines of Table 1.1 for each of the following engineering systems: a. A ship. b. A commercial passenger aircraft. c. Your household. d. A chemical process control plant. 1.3 Electric power systems provide energy in a variety of commercial and industrial settings. Make a list of systems and devices that receive electric power in a. A large office building. b. A factory floor. c. A construction site. January 11, 2008 15:41 Chap02 Sheet number 1 Page number 8 magenta black PART I CIRCUITS Chapter 2 Fundamentals of Electric Circuits Chapter 3 Resistive Network Analysis Chapter 4 AC Network Analysis Chapter 5 Transient Analysis Chapter 6 Frequency Response and System Concepts Chapter 7 AC Power - January 11, 2008 15:41 Chap02 C H Sheet number 2 Page number 9 A P T E magenta black R 2 FUNDAMENTALS OF ELECTRIC CIRCUITS hapter 2 presents the fundamental laws that govern the behavior of electric circuits, and it serves as the foundation to the remainder of this book. The chapter begins with a series of definitions to acquaint the reader with electric circuits; next, the two fundamental laws of circuit analysis are introduced: Kirchhoff’s current and voltage laws. With the aid of these tools, the concepts of electric power and the sign convention and methods for describing circuit elements—resistors in particular—are presented. Following these preliminary topics, the emphasis moves to basic analysis techniques—voltage and current dividers, and to some application examples related to the engineering use of these concepts. Examples include a description of strain gauges, circuits for the measurements of force and other related mechanical variables, and of the study of an automotive throttle position sensor. The chapter closes with a brief discussion of electric measuring instruments. The following box outlines the principal learning objectives of the chapter. 9
- Xem thêm -