Basic Electrical Engineering D. C. Kulshreshtha PDF

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Scilab Textbook Companion for Basic Electrical Engineering by D. C. Kulshreshtha1 Created by Akhtar Ali Shah B.E (EXTC) Electronics Engineering AI’S Kalsekar Technical Campus New Panvel College Teacher Mrs.chaya.s Cross-Checked by Chaitanya Potti July 31, 2019

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Funded by a grant from the National Mission on Education through ICT, http://spoken-tutorial.org/NMEICT-Intro. This Textbook Companion and Scilab codes written in it can be downloaded from the ”Textbook Companion Project” section at the website http://scilab.in

Book Description Title: Basic Electrical Engineering Author: D. C. Kulshreshtha Publisher: Tata McGraw Hill, New Delhi Edition: 1 Year: 2009 ISBN: 0-07-014100-2

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Scilab numbering policy used in this document and the relation to the above book. Exa Example (Solved example) Eqn Equation (Particular equation of the above book) AP Appendix to Example(Scilab Code that is an Appednix to a particular Example of the above book) For example, Exa 3.51 means solved example 3.51 of this book. Sec 2.3 means a scilab code whose theory is explained in Section 2.3 of the book.

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Contents List of Scilab Codes

4

2 Ohms law

5

3 Network Analysis

19

4 Network Theorems

45

5 Electromagnetism

55

6 Magnetic Circuits

62

7 Self And Mutual Inductances

66

8 DC Transients

77

9 Alternating Voltage And Current

87

10 AC Circuits

100

11 Resonance in AC Circuits

108

12 Three Phase Circuits And System

117

13 Transformers

124 3

14 Alternators And Synchronous Motors

142

15 Induction Motors

151

16 DC Machines

160

17 Fractional Horse Power Motors

178

18 Electrical Measuring Instruments

183

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List of Scilab Codes Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10

Resistance . . . . . . Resistance . . . . . . Resistance . . . . . . Voltage And Current Resistance . . . . . . Current . . . . . . . Current . . . . . . . Voltage . . . . . . . Resistance . . . . . . Resistance . . . . . . Resistance . . . . . . Resistance . . . . . . Cost . . . . . . . . . Rating . . . . . . . . Resistance . . . . . . Resistance . . . . . . Resistance . . . . . . Temperature . . . . capacitor . . . . . . Inductor . . . . . . . Inductor . . . . . . . Voltage . . . . . . . Voltage . . . . . . . Voltage And Energy Capacitor . . . . . . Voltage And Current Voltage And Power . Current . . . . . . . 5

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5 6 6 7 8 9 10 10 11 12 13 13 14 15 15 16 17 17 19 20 21 22 23 24 25 26 28 29

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 2.26 2.27 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 6.1 6.2 6.3 6.4

Current And Power . . . . . . . . . Voltage . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Resistance . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . Voltage And Power . . . . . . . . . Current And Resistance . . . . . . Current . . . . . . . . . . . . . . . Megnetic Field Strength . . . . . . Force . . . . . . . . . . . . . . . . . Force . . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . Voltage Time And Force . . . . . . Megnetic Field Strength And Flux Megnetomotive Force . . . . . . . . Reluctance And Current . . . . . . Current . . . . . . . . . . . . . . . 6

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30 31 31 32 34 35 35 36 37 38 39 40 41 42 43 45 46 47 48 49 50 50 51 52 53 54 55 55 56 57 58 58 59 60 62 63 63 64

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10 9.11 9.12 9.13 9.14 9.15 10.1 10.2 10.3

Voltage . . . . . . . . . . . . . . . . Inductor And Voltage . . . . . . . . Inductor And Voltage . . . . . . . . Inductor And Energy . . . . . . . . . Megnetic Field Strength And Voltage Voltage . . . . . . . . . . . . . . . . Inductor And Voltage . . . . . . . . Inductor . . . . . . . . . . . . . . . . Inductor . . . . . . . . . . . . . . . . Inductor . . . . . . . . . . . . . . . . Inductor . . . . . . . . . . . . . . . . Inductor . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . . Current And Power . . . . . . . . . . Current And Time . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Voltage And Current . . . . . . . . . Voltage And Current . . . . . . . . . Current . . . . . . . . . . . . . . . . Voltage And Angle . . . . . . . . . . Voltage Time And Frequency . . . . Voltage . . . . . . . . . . . . . . . . Current And Time . . . . . . . . . . Time . . . . . . . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . . Current And Power Factor . . . . . . Voltage And Power Factor . . . . . . Power And Power Factor . . . . . . . Current Power And Power Factor . . Current Power And Power Factor . . Resistance Voltage And Power . . . 7

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66 66 67 68 68 69 70 71 72 73 74 75 77 78 79 80 81 83 84 85 87 87 88 89 90 91 92 92 93 94 94 95 96 97 98 100 101 102

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

10.4 10.5 10.6 10.7 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 12.1 12.2 12.3 12.4 12.5 12.6 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13 13.14 13.15 13.16 14.1 14.2 14.3 14.4

Resistance Power And Power Factor Reluctance And Inductor . . . . . . . Resistance And Capacitor . . . . . . Resistance Power And Power Factor Frequence And Voltage . . . . . . . . Capacitor Voltage And Q FActor . . Inductor Current And Voltage . . . . Capacitor Current And Enegy . . . . Frequence And Q Factor . . . . . . . Frequence . . . . . . . . . . . . . . . Resistance Current And Capacitor . Frequence And Q Factor . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Current Power And Power Factor . . Power And Power Factor . . . . . . . Current Power And Power Factor . . Megnetic Flux And Voltage . . . . . Flux Density Current And Voltage . Turns Ratio . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . . Turns . . . . . . . . . . . . . . . . . Current And Power Factor . . . . . . Power . . . . . . . . . . . . . . . . . Current And Power Factor . . . . . . Resistance And Power . . . . . . . . Regulation . . . . . . . . . . . . . . . Efficiency And Power . . . . . . . . . Efficiency . . . . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . . Current And Resistance . . . . . . . Speed . . . . . . . . . . . . . . . . . Distribution Factor . . . . . . . . . . Speed Emf And Voltage . . . . . . . Voltage Regulation . . . . . . . . . . 8

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103 104 105 106 108 109 110 111 112 113 114 115 117 118 119 120 121 122 124 125 126 126 127 128 129 130 131 132 134 135 137 138 139 140 142 143 143 144

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

14.5 14.6 14.7 14.8 14.9 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8 16.1 16.2 16.3 16.4 16.5 16.6 16.7 16.8 16.9 16.10 16.11 16.12 16.13 16.14 16.15 16.16 16.17 16.18 16.19 16.20 17.1 17.2 17.3 17.4 17.5

Voltage Regulation . . . . . . . . . . . . Emf And Angle . . . . . . . . . . . . . . Emf . . . . . . . . . . . . . . . . . . . . Emf . . . . . . . . . . . . . . . . . . . . Current Power And Torque . . . . . . . Speed And Frequency . . . . . . . . . . Speed And Frequency . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . Speed And Frequency . . . . . . . . . . Current . . . . . . . . . . . . . . . . . . Power And Speed . . . . . . . . . . . . . Current Power And Speed . . . . . . . . Resistance . . . . . . . . . . . . . . . . . Voltage Current And Power . . . . . . . Emf . . . . . . . . . . . . . . . . . . . . Emf . . . . . . . . . . . . . . . . . . . . Speed And increase in flux . . . . . . . . Voltage . . . . . . . . . . . . . . . . . . Voltage And Current . . . . . . . . . . . Emf . . . . . . . . . . . . . . . . . . . . Voltage Efficiency And Power . . . . . . Current And Resistance . . . . . . . . . Turns . . . . . . . . . . . . . . . . . . . Voltage . . . . . . . . . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . Speed And Torque . . . . . . . . . . . . Power . . . . . . . . . . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . Current . . . . . . . . . . . . . . . . . . Speed And Torque . . . . . . . . . . . . Resistance . . . . . . . . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . Slip And Efficiency . . . . . . . . . . . . Current Phase Angle And Power Factor Capacitor . . . . . . . . . . . . . . . . . Revolution Steps And Speed . . . . . . . No of Rotors And Stators . . . . . . . . 9

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146 147 148 149 150 151 152 153 153 154 156 157 159 160 161 162 162 163 164 165 166 167 168 169 169 170 171 172 172 173 174 175 176 178 179 180 181 181

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

17.6 18.1 18.2 18.4 18.5 18.6 18.7 18.8 18.9 18.10

No of Rotors And Stators Theeth . Torque . . . . . . . . . . . . . . . . Resistance . . . . . . . . . . . . . . Resistance . . . . . . . . . . . . . . Resistance And Multiplying Factor Voltage And Error . . . . . . . . . Angle of Deflection . . . . . . . . . Deflection in the Torque . . . . . . Angle of Deflection . . . . . . . . . Current . . . . . . . . . . . . . . .

10

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182 183 184 184 185 186 187 187 188 189

Chapter 2 Ohms law

Scilab code Exa 2.1 Resistance 1 2 3 4 5 6 7 8 9 10 11

// Example

2.1

// R e l a t i v e a r e a o f wi r e −A a1 = %pi *2 ^2/4 ; a2 = %pi *1/4 ; // R e l a t i v e a r e a o f wi r e −B l1 =1; // R e l a t i v e l e n g h t o f w i r e −B l2 =4; // R e l a t i v e l e n g h t o f w i r e −B R1 =5; // R e s i s t a n c e o f w i r e r =( l2 / a2 ) /( l1 / a1 ); disp ( ’ The r a t i o o f r e s i s t a n c e s ( R2/R1 ) = ’ + string ( r ) + ’ ohm ’ ) ; 12 R2 =r * R1 ; 13 disp ( ’ R e s i s t a n c e ( R2 ) = ’ + string ( R2 ) + ’ ohm ’ );

14 15 16 17 18 19

// p

16

2.1

11

Scilab code Exa 2.2 Resistance 1 2 3 4 5 6 7 8 9 10 11

// Example

2.2

// R e l a t i v e a r e a o f wi r e −A a1 = %pi *3/4 ; a2 = %pi *1/4 ; // R e l a t i v e a r e a o f wi r e −B l1 =1; // R e l a t i v e l e n g h t o f w i r e −A l2 =3; // R e l a t i v e l e n g h t o f w i r e −B R1 =10; // R e s i s t a n c e o f w i r e r =( l2 / a2 ) /( l1 / a1 ); disp ( ’ The r a t i o o f r e s i s t a n c e s ( R2/R1 ) = ’ + string ( r ) + ’ ohm ’ ) ; 12 R2 =r * R1 ; 13 disp ( ’ R e s i s t a n c e ( R2 ) = ’ + string ( R2 ) + ’ ohm ’ );

14 15 16 17 18 19 20 21

//

p 16

2.2

Scilab code Exa 2.3 Resistance 1 2 3 4 5

// Example //

Rp=(4+4) | | ( 8 + 4 )

12

2.3

6 Rp =(8*12) /(8+12) ; // By V o l t a g e d i v i d e r r u l e 7 disp ( ’ v o l t a g e A c r o s s Foue r e s i s r a n c e = ’ + string ( Rp )

+ ’ Ohm ’ ) ; 8 9 10 11 12 13

//

p 20

2.3

Scilab code Exa 2.4 Voltage And Current 1 2 // Example 2 . 4 3 4 5 v =8 . 8* { 2/ (2 + 2. 4) }; // by v o l t a g e d i v i d e r r u l e 6 disp ( ’ Anknown V o l t a g e a c r o s s t h e R1 = ’ + string ( v ) + ’

v o l t ’ ); 7 8 v1 = 8 . 8 * { 2 . 4 / ( 2 + 2 . 4 ) }; / / by v o l t a g e d i v i d e r r u l e 9 disp ( ’ Anknown V o l t a g e a c r o s s t h e R1 = ’ + string ( v1 ) + 10 11 12 13 14 15 16 17 18 19

’ v o l t ’ ); i =4.8/4; disp ( ’ Anknown C u r r e n t i1 =4.8/6; disp ( ’ Anknown C u r r e n t

// I=V/R I 1 = ’ + string ( i ) + ’ Amp ’ ) ; / / I=V/R I 2 = ’ + string ( i1 ) + ’ Amp ’ ) ;

// p 2 0

2.4

13

Scilab code Exa 2.5 Resistance 1 2 // Example 2 . 5 3 // From t h e d ia gr a m 2 . 1 4 4 5 // P a r a l l e l 6 rp =(1/20) +(1/10) +(1/20) ; 7 8 9 10

resistance Rp =1/ rp ; // The r e s i s t a n c e Rp Rs =15; // S e r i e s r e s i s t a n c e Rab = Rs + Rp ; // E f f e c t i v e r e s i s t a n c e b et ween A & B disp ( ’ ( a ) E f f e c t i v e r e s i s t a n c e b et w een A & B f o r d i a gr a m ( a ) = ’ + string ( Rab ) + ’ Ohms ’ );

11 12 13 R1 =5/3 ;

// f o r d i a g r am ( b ) n et w o r k a b o ve l i n e AB i . e R1 = [ (R+R) | | R]+R // R e s i s t a n c e o f

n et w o r k // The l o w e r p a r t i s a l s o same a s R1 15 R12 =5/ 6; // C o m b i n a ti o n o f R1 & R2 16 Rab1 =( R12 *1) /( R12 +1) ; // E f f e c t i v e r e s i s t a n c e b et ween A & B f o r d i a g ra m ( b ) 17 disp ( ’ ( b ) E f f e c t i v e r e s i s t a n c e b et w een A & B f o r d i a gr a m ( b ) = ’ + string ( Rab1 ) + ’ R ’ ) ; 14 R2 = R1 ;

18 // f o r d i a g r a m ( c ) 19 20 r1 =(3*6) /(3+6) ;

// P a r a l l e l c o m b i n a t i o n o f 3 & 6 Ohms R e s i s t a n c e 21 Ri = r1 +18; // s e r i e s o f r 1 & 18 Ohms R e s i s t a n c e 14

rab =( 20 *2 0) /( 20 +2 0) ; // P a r a l l e l c o m b i n a t u i o n o f Ri & 20 Ohms R e s i s t a n c e 23 Rab2 = rab +5; // s e r i e s o f r a b & 2 Ohms R e s i s t a n c e 24 disp ( ’ ( c ) E f f e c t i v e r e s i s t a n c e b etw een A & B f o r d i a gr a m ( c ) = ’ + string ( Rab 2 )+ ’ Ohms ’ ) ; 22

25 26 27 28 29

//

p 23

2.5

Scilab code Exa 2.6 Current 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

// Example

2.6

d =(1/12) +(1/20) +(1/30) ; // E f f e c t i v e R e s i s r e n c e Reff = 2+( 1/ d ) ; v =10 0; I =v / Reff ; // ( bu t 1 2 i 1= 2 0 i 2= 3 0 i 3 ) // i 2 = 1 2 / 2 0 ∗ i 1 & i 3= 1 2 / 3 0 ∗ i 1 // bu t 10= i 1+i 2 +i 3 // 0 . 6 i 1 + 0. 4 i 1 +i 1 =10 i . e i 1 =5 i1 =5; disp ( ’ C u r r en t o f I 1 i f = ’ + string ( i1 ) + ’ Amp ’ ) ; i2 =0.6 * i1 ; disp ( ’ C u r r en t o f I 2 i f = ’ + string ( i2 ) + ’ Amp ’ ) ; i3 =0.4 * i1 ; disp ( ’ C u r r en t o f I 3 i f = ’ + string ( i3 ) + ’ Amp ’ ) ;

//

p 24

2.6 15

Scilab code Exa 2.7 Current 1 2 3 4 5 6 7 8 9 10 11 12 13 14

// Example //

p=i 1 ˆ2 ∗ Rl

i.e

2.7 i 1=p/ Rl

// Load r e s i s t a n c e // Power

Rl =5; p =20; i1 =p / Rl ;

// i 1 = i ∗ (R/R+Rl ) i . e i = i 1 ∗ (R+Rl ) /R i =2 *( 10 +5 ) /10; disp ( ’ S u p p ly C u r r en t i s = ’ + string ( i ) + ’ Amp ’ ) ;

// p 2 5

2.7

Scilab code Exa 2.8 Voltage 1 2 // Example 2 . 8 3 // Su p p l y v o l t a g e 4 v =12 0; 5 p =60; // Power 6 R =v ^2/ p ; // R e s i s t a n c e 7 // t h e c o m b i n a t i o n R o f b ul b B & C i s Rbc 8 9 10 11

//

=240/2 vb=v c

Rbc =240/2;

i . e Rbc=120

/ / R o f ea c h b u l b 16

12 k =2 40 +1 20 ; 13 vc = Rbc *(1 20/ k ) ; 14 15 16 17 18 19 20

// v o l t a c r o s s Vc & Vb { u s i n g Volt D i v i d er Rule } va =120 - 40; // v o l t a c r o s s Va disp ( ’ t h e V o l t a g e a c r o s s b u lb A & B = ’ + string ( vc ) + ’ V o l t ’ ); disp ( ’ t h e V o l t a g e a c r o s s b u lb C = ’ + strin g ( va )+ ’ V o l t ’ ); vb =40; // p=pa+pb p =( va ) ^ 2/24 0+( vb ) ^ 2/2 40+ ( vc ) ^2 /24 0; +p c t o t a l po wer disp ( ’ T o t a l e Power D i s s i p a t e d i s = ’ + string ( p ) + ’ Watt ’ ) ;