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This page is intentionally left blank GATE (Graduate Aptitude Test in Engineering) Electrical Engineering T K s rishna nowledge ysTems Copyright © 2017 Trishna Knowledge Systems Published by Pearson India Education Services Pvt. Ltd, CIN: U72200TN2005PTC057128, formerly known as TutorVista Global Pvt. Ltd, licensee of Pearson Education in South Asia. No part of this eBook may be used or reproduced in any manner whatsoever without the publisher’s prior written consent. This eBook may or may not include all assets that were part of the print version. The publisher reserves the right to remove any material in this eBook at any time. ISBN 978-93-528-6843-8 eISBN 978-93-530-6117-3 Head Office: 15th Floor, Tower-B, World Trade Tower, Plot No. 1, Block-C, Sector 16, Noida 201 301, Uttar Pradesh, India. Registered Office: 4th Floor, Software Block, Elnet Software City, TS-140, Block 2 & 9, Rajiv Gandhi Salai, Taramani, Chennai 600 113, Tamil Nadu, India. Fax: 080-30461003, Phone: 080-30461060 www.pearson.co.in, Email: [email protected] Contents Preface ix Key Pedagogical feaTures x syllabus: elecTrical engineering xii chaPTer-wise analysis of gaTe Previous years’ PaPers xiii general informaTion abouT gaTe xiv solved PaPers 2017 xvi solved PaPers 2018 lvii ParT 1 g a eneral PTiTude ParT a Verbal ability chaPTer 1 Grammar 1.5 chaPTer 2 Vocabulary 1.49 ParT b Numerical ability uniT i Q a 1.71 uanTiTaTive PTiTude chaPTer 1 Simple equatioNS 1.73 chaPTer 2 ratio-proportioN-VariatioN 1.79 chaPTer 3 NumberS 1.85 chaPTer 4 perceNtage, profit aNd loSS 1.99 chaPTer 5 Simple iNtereSt aNd compouNd iNtereSt 1.106 chaPTer 6 aVerageS, mixtureS aNd alligatioNS 1.112 chaPTer 7 time aNd Work 1.119 chaPTer 8 time aNd diStaNce 1.125 chaPTer 9 iNdiceS, SurdS, logarithmS 1.131 chaPTer 10 quadratic equatioNS 1.137 chaPTer 11 iNequalitieS 1.143 chaPTer 12 progreSSioNS 1.147 chaPTer 13 permutatioNS aNd combiNatioNS 1.152 chaPTer 14 data iNterpretatioN 1.159 uniT ii r 1.177 easoning chaPTer 1 Number aNd letter SerieS 1.179 chaPTer 2 aNalogieS 1.185 chaPTer 3 odd maN out (claSSificatioN) 1.188 chaPTer 4 codiNg aNd decodiNg 1.191 chaPTer 5 blood relatioNS 1.195 chaPTer 6 VeNN diagramS 1.200 vi | Contents chaPTer 7 SeatiNg arraNgemeNtS 1.204 chaPTer 8 puzzleS 1.212 chaPTer 9 clockS aNd caleNderS 1.225 ParT i1 e m ngineering aThemaTics chaPTer 1 liNear algebra 2.3 chaPTer 2 calculuS 2.19 chaPTer 3 differeNtial equatioNS 2.46 chaPTer 4 complex VariableS 2.65 chaPTer 5 probability aNd StatiSticS 2.81 chaPTer 6 Numerical methodS 2.100 chaPTer 7 traNSform theory 2.111 ParT iii e e lecTrical ngineering uniT 1 s s 3.1 ignals and ysTems chaPTer 1 iNtroductioN to SigNalS aNd SyStemS 3.5 chaPTer 2 laplace traNSform 3.36 chaPTer 3 z-traNSform 3.50 chaPTer 4 coNtiNuouS time fourier aNalySiS 3.67 uniT ii a d e 3.91 nalog and igiTal lecTronics chaPTer 1 diode circuitS 3.93 chaPTer 2 bipolar JuNctioN traNSiStorS 3.119 chaPTer 3 field effect traNSiStorS 3.137 chaPTer 4 traNSiStor biaSiNg 3.156 chaPTer 5 amplifierS 3.174 chaPTer 6 differeNtial aNd feedback amplifierS 3.198 chaPTer 7 operatioNal amplifierS 3.217 chaPTer 8 booleaN algebra aNd miNimizatioN of fuNctioNS 3.256 chaPTer 9 combiNatioNal circuitS 3.283 chaPTer 10 SequeNtial circuitS 3.305 chaPTer 11 Sample aNd hold, a/d aNd d/a circuitS 3.330 chaPTer 12 microproceSSor 8085 3.337 Contents | vii uniT iii e c f 3.359 lecTric ircuiTs and ields chaPTer 1 NetWork elemeNtS aNd baSic laWS 3.361 chaPTer 2 NetWork theoremS 3.387 chaPTer 3 traNSieNt aNalySiS (ac aNd dc) 3.409 chaPTer 4 tWo port NetWorkS 3.440 chaPTer 5 reSoNaNce 3.471 chaPTer 6 filterS aNd field theory 3.492 uniT iv e m 3.515 lecTrical achines chaPTer 1 traNSformerS 3.517 chaPTer 2 priNcipleS of electro mechaNical eNergy coNVerSioN 3.547 chaPTer 3 dc machiNeS 3.558 chaPTer 4 iNductioN motorS 3.586 chaPTer 5 SyNchroNouS machiNeS 3.613 uniT v P e d 3.643 ower lecTronics and rives chaPTer 1 poWer SemicoNductor deViceS 3.645 chaPTer 2 ac to dc coNVerterS (or) rectifierS 3.667 chaPTer 3 dc–dc coNVerterS (or) chopperS 3.694 chaPTer 4 dc–ac coNVerterS (or) iNVerterS 3.713 chaPTer 5 ac Voltage coNVerterS (or) coNtrollerS aNd electric driVeS 3.733 uniT vi e e m 3.761 lecTrical and lecTronic easuremenTs chaPTer 1 error aNalySiS aNd r, l, c meaSuremeNtS 3.763 chaPTer 2 electrical meaSuriNg iNStrumeNtS 3.784 chaPTer 3 meaSuremeNt of poWer aNd eNergy 3.801 chaPTer 4 cathode ray oScilloScope aNd electroNic VoltmeterS 3.815 chaPTer 5 magNetic meaSuremeNtS aNd traNSducerS 3.828 uniT vii P s 3.845 ower ysTems chaPTer 1 poWer SyStem geNeratioN, traNSmiSSioN aNd diStributioN 3.847 chaPTer 2 fault aNalySiS 3.905 chaPTer 3 load floW aNalySiS aNd protectioN 3.927 chaPTer 4 poWer SyStemS Stability 3.956 chaPTer 5 hVdc aNd factS 3.971 viii | Contents uniT viii c s 3.979 onTrol ysTems chaPTer 1 iNtroductioN to coNtrol SyStemS 3.981 chaPTer 2 time reSpoNSe aNalySiS 3.999 chaPTer 3 Stability aNalySiS 3.1014 chaPTer 4 coNtrollerS aNd compeNSatorS 3.1045 chaPTer 5 State Space aNalySiS 3.1055 Preface Graduate Aptitude Test in Engineering (GATE) is one of the preliminary tests for undergraduate subjects in Engineering/ Technology/Architecture and postgraduate subjects in Science stream only. The number of aspirants appearing for the GATE examination is increasing significantly every year, owing to multifac- eted opportunities open to any good performer. Apart from giving the aspirant a chance to pursue an M.Tech. from insti- tutions like the IITs /NITs, a good GATE score can be highly instrumental in landing the candidate a plush public sector job, as many PSUs are recruiting graduate engineers on the basis of their performance in GATE. The GATE examination pattern has undergone several changes over the years—sometimes apparent and sometimes subtle. It is bound to continue to do so with changing technological environment. GATE Electrical Engineering, as a complete resource helps the aspirants be ready with conceptual understanding, and enables them to apply these concepts in various applications, rather than just proficiency with questions type. Topics are handled in a comprehensive manner, beginning with the basics and progressing in a step-by-step manner along with a bottom-up approach. This allows the student to better understand the concept and to practice applicative techniques in a focused manner. The content has been systematically organized to facilitate easy understanding of all topics. The given examples will not only help the students to understand the concepts involved in the problems but also help to get a good idea about the different models of problems on that particular topic. Due care has also been taken to cover a very wide range of problems including questions that have been appearing over the last few years in GATE examination. The practice exercises in every chapter, contain questions ranging simple to moderate to difficult level. These exercises are meant to hone the examination readiness over a period of time. At the end of each unit, practice tests have been placed. These tests will help the student assess their level of learning on a regular interval. This book has been prepared by a group of faculty who are highly experienced in training GATE preparations and are also subject matter experts. As a result, this book would serve as an effective tool for GATE aspirant to crack the examination. Salient Features 1. Elaborate question bank covering previous 12 years’ GATE question papers 2. 5 free online mock tests for practice 3. Detailed coverage of key topics 4. Complete set of solved 2017 GATE online papers with chapter-wise analysis 5. Exhaustive pedagogy: (a) More than 1300 Solved Examples (b) More than 6000 Practice Questions (c) Unit-wise time-bound tests (d) Modular approach for easy understanding We would like to thank the below mentioned reviewers for their valuable feedback and suggestions which has helped in shaping this book. R. Marudhachalam Professor (Sr. Grade), Kumaraguru College of Technology Coimbatore, Tamil Nadu Daya Gupta Professor, Delhi Technological University, Main Bawana Road, Delhi Manoj Kumar Gupta Associate Professor, Delhi Technological University Main Bawana Road, Delhi Gurpreet Kour Lecturer, Lovely Professional University Phagwara, Punjab Pinaki Chakraborty Assistant Professor, Netaji Subhas Institute of Technology Dwarka, Delhi Gunit Kaur Lecturer, Lovely Professional University Phagwara, Punjab Despite of our best efforts, some errors may have inadvertently crept into the book. Constructive comments and sugges- tions to further improve the book are welcome and shall be acknowledged gratefully. Wishing you all the very best..!!! —Trishna Knowledge Systems