initial commit / add all books

20 files changed, 514 insertions, 0 deletions

diff --git a/1938/CH4/EX4.1/4_1.jpg b/1938/CH4/EX4.1/4_1.jpg
new file mode 100755
index 000000000..81fdf149e
--- /dev/null
+++ b/1938/CH4/EX4.1/4_1.jpg
diff --git a/1938/CH4/EX4.1/4_1.sce b/1938/CH4/EX4.1/4_1.sce
new file mode 100755
index 000000000..9a0599fe3
--- /dev/null
+++ b/1938/CH4/EX4.1/4_1.sce
@@ -0,0 +1,9 @@
+clc,clear

+printf('Example 4.1\n\n')

+

+Pole=4

+Slots=24

+Phase=3 //number of phases

+n=Slots/Pole //slots per pole

+m=Slots/Pole/Phase //slots per pole per phase

+beeta=180/n  //Slot angle

diff --git a/1938/CH4/EX4.10/4_10.sce b/1938/CH4/EX4.10/4_10.sce
new file mode 100755
index 000000000..8f7ebfb42
--- /dev/null
+++ b/1938/CH4/EX4.10/4_10.sce
@@ -0,0 +1,36 @@
+clc,clear

+printf('Example 4.10\n\n')

+

+Slots=180

+Pole=12

+Ns=600 //Synchronous speen in rpm

+f=Pole*Ns/120 //frequency

+phi=0.05 //flux per pole in weber

+

+//Part(i)

+//Average EMF in a conductor=2*f*phi

+rms_value_1=1.11*2*f*phi //rms value of emf in a conductor

+printf('(i)r.m.s value of e.m.f in a conductor is %.2f V ',rms_value_1)

+

+//part(ii)

+//Average EMF in a turn=4*f*phi

+rms_value_2=1.11*4*f*phi//r.m.s value of e.m.f in a turn

+printf('\n(ii)r.m.s value of e.m.f in a turn is %.2f V ',rms_value_2)

+

+//part(iii)

+conductors_per_coilside=10/2 

+rms_value_3=rms_value_2*conductors_per_coilside  //r.m.s value of e.m.f in a coil

+printf('\n(iii)r.m.s value of e.m.f in a coil is %.1f V ',rms_value_3)

+

+//part(iv)

+conductors_per_slot=10

+Z=conductors_per_slot * Slots  //total number of conductors

+Z_ph=Z/3    //conductors per phase

+T_ph=Z_ph/2 //turns per phase

+n=Slots/Pole  //slots per pole

+m=n/3        //slots per pole per phase 

+beeta=180/n   //slot angle

+

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)),K_c=1  //distribution & coil-span factor

+E_ph=rms_value_2*T_ph*K_d*K_c   //induced emf

+printf('\n(iv)per phase induced e.m.f is %.1f V ',E_ph)

diff --git a/1938/CH4/EX4.11/4_11.sce b/1938/CH4/EX4.11/4_11.sce
new file mode 100755
index 000000000..105d03d46
--- /dev/null
+++ b/1938/CH4/EX4.11/4_11.sce
@@ -0,0 +1,34 @@
+clc,clear

+printf('Example 4.11\n\n')

+

+Pole=8

+f=50 //frequency

+phi=60*10^-3 //flux per pole in weber

+Slots=96 

+n=Slots/Pole //slots per pole

+beeta = 180/n //slot angle 

+m=n/3 //slots per pole per phase

+

+coil_pitch=10*beeta //10 slots

+alpha=180-coil_pitch

+K_c=cosd(alpha/2)   //coi;-span factor

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //distribution factor

+

+conductors_per_slot=4  

+Z=Slots*conductors_per_slot //total conductors

+Total_turns=Z/2  

+T_ph=Total_turns/3  //turns per phase

+

+//part (i)

+E_ph= 4.44 *K_c *K_d *phi *f *T_ph

+printf('\The phase voltage is %.2f V ',E_ph)

+

+//part(ii)

+E_line=E_ph*sqrt(3)

+printf('\nThe Line Voltage is %.2f V ',E_line)

+

+ //part(iii)

+I_ph=650

+I_l=I_ph  // Star Connection

+kVA_rating=sqrt(3)*E_line*I_l

+printf('\nkVA rating is %.1f kVA ',kVA_rating/1000)

diff --git a/1938/CH4/EX4.12/4_12.sce b/1938/CH4/EX4.12/4_12.sce
new file mode 100755
index 000000000..02f40a617
--- /dev/null
+++ b/1938/CH4/EX4.12/4_12.sce
@@ -0,0 +1,48 @@
+clc,clear

+printf('Example 4.12\n\n')

+

+Ns=600 //synchronous speed in rpm

+Pole=10

+l=30/100     //divided by 100 for centimetre-metre conversion

+Pole_pitch=35/100  //numerically equal to pi*d/Pole

+Phase=3

+conductors_per_slot=8

+A1=Pole_pitch*l //Area of each fundamental pole

+m=3   //Slot per Pole per Phase

+n=Phase*m //slots per pole

+beeta=180/n  //slot angle

+

+B_m1=1,B_m3=0.3,B_m5=0.2  //amplitude of 1st, 3rd and 5th harmonic

+phi_1=(2/%pi)*A1*B_m1  //average value of fundamental flux per pole 

+f=Ns*Pole/120 //frequency

+

+Coil_span=(8/9)*180

+alpha=180-Coil_span

+//pitch factor for 1st, 3rd and 5th harmonic

+K_c1=cosd(alpha/2)  

+K_c3=cosd(3*alpha/2)

+K_c5=cosd(5*alpha/2)

+

+// using K_dx=sin(m*x*beeta*(%pi/180)/2) /(m*sin(x*beeta*(%pi/180)/2))

+//distribution factor for 1st, 3rd and 5th harmonic

+K_d1=sind(m*1*beeta/2) /(m*sind(1*beeta/2))

+K_d3=sind(m*3*beeta/2) /(m*sind(3*beeta/2))

+K_d5=sind(m*5*beeta/2) /(m*sind(5*beeta/2))

+

+Slots=n*Pole

+Total_conductors=conductors_per_slot * Slots

+Total_turns=Total_conductors/2

+T_ph=Total_turns/3  //turns per phase

+

+//EMF of 1st , 3rd and 5th harmonic

+E_1ph=4.44 * K_c1 * K_d1*phi_1 * f * T_ph

+E_3ph= E_1ph* (B_m3*K_c3*K_d3)/(B_m1*K_c1*K_d1)

+E_5ph= E_1ph* (B_m5*K_c5*K_d5)/(B_m1*K_c1*K_d1)

+

+// Using E_xph= E_1ph* (B_mx*K_cx*K_dx)/(B_m1*K_c1*K_d1)

+E_ph=sqrt( E_1ph^2 + E_3ph^2 + E_5ph^2 )

+printf('Phase value of induced e.m.f is %.2f V ',E_ph)

+E_line=sqrt(3) * sqrt( E_1ph^2 + E_5ph^2  )//no 3rd harmonic appears in line value

+printf('\nline value of induced e.m.f is %.2f V ',E_line)

+

+printf('\n\nAnswer mismatches due to approximation')

diff --git a/1938/CH4/EX4.13/4_13.sce b/1938/CH4/EX4.13/4_13.sce
new file mode 100755
index 000000000..41b99f92a
--- /dev/null
+++ b/1938/CH4/EX4.13/4_13.sce
@@ -0,0 +1,22 @@
+clc,clear

+printf('Example 4.13\n\n')

+

+Pole=16

+phi=0.03 //flux per pole

+Ns=375 //synchronous speed in rpm

+f=Ns*Pole/120 //frequency

+printf('frequency is %.0f Hz ',f)

+Slots=144

+n=Slots/Pole  //slots per pole

+m=n/3 //slots per pole per phase

+beeta=180/n  //slot angle

+K_c=1 //assuming Full-Pitch coil

+Conductors_per_slot=10

+K_d=sind(m*beeta/2) /(m*sind(beeta/2))  //distribution factor

+

+Total_conductors=Slots*Conductors_per_slot

+Total_turns=Total_conductors/2

+T_ph=Total_turns/3  //turns per phase

+E_ph=4.44* K_c* K_d*phi* f* T_ph

+E_line=E_ph*sqrt(3)

+printf('\nline voltage is %.2f V ',E_line)

diff --git a/1938/CH4/EX4.14/4_14.sce b/1938/CH4/EX4.14/4_14.sce
new file mode 100755
index 000000000..0bf84be33
--- /dev/null
+++ b/1938/CH4/EX4.14/4_14.sce
@@ -0,0 +1,28 @@
+clc,clear

+printf('Example 4.14\n\n')

+

+Ns=250 //Speed in rpm

+f=50 //frequency

+I_l=100

+Slots=216

+Conductors_per_slot=5

+Pole=120*f/Ns

+phi=30*10^-3//flux per pole in weber

+Z=Slots*Conductors_per_slot  //Total Conductors

+Z_ph=Z/3 //conductors per phase

+T_ph=Z_ph/2 //turns per phase

+n=Slots/Pole //slots per pole

+m=n/3 //slots per pole per phase

+beeta=180/n //Slot angle

+

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //distribution factor

+

+e_av=2*f*phi     //Average Value of EMF in each conductor

+E_c=1.11*(2*f*phi)  //RMS value of EMF in each conductor

+E=2*E_c*K_d //RMS value of EMF in each turn

+E_ph=T_ph*E //RMS value of EMF in each phase

+E_line= E_ph*sqrt(3)  //As Star Connected Alternator

+printf('RMS value of EMF in each phase = %.3f V\n',E_ph)

+printf('RMS value of EMF line value  = %.3f V\n',E_line)

+kVA_rating=sqrt(3)*E_line*I_l

+printf('\nkVA rating is %.3f kVA ',kVA_rating/1000)

diff --git a/1938/CH4/EX4.15/4_15.sce b/1938/CH4/EX4.15/4_15.sce
new file mode 100755
index 000000000..fd013fe12
--- /dev/null
+++ b/1938/CH4/EX4.15/4_15.sce
@@ -0,0 +1,21 @@
+clc,clear

+printf('Example 4.15\n\n')

+

+Pole=10

+Slots=90

+E_l=11000

+f=50

+phi=0.15 //flux per pole in weber

+n=Slots/Pole //slots per pole

+m=n/3 //slots per pole per phase

+beeta=180/n //slot angle

+ 

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //distribution factor

+K_c=1 //coil span factor

+

+E_ph=E_l/sqrt(3)

+T_ph=floor( E_ph/(4.44*K_c*K_d*phi*f)  )

+//T_ph should necessarily be an integer

+

+Z_ph=(T_ph)*2  

+printf('Required number of armature conductors is %d',Z_ph)

diff --git a/1938/CH4/EX4.16/4_16.sce b/1938/CH4/EX4.16/4_16.sce
new file mode 100755
index 000000000..6be2bff7c
--- /dev/null
+++ b/1938/CH4/EX4.16/4_16.sce
@@ -0,0 +1,41 @@
+clc,clear

+printf('Example 4.16\n\n')

+

+Pole=10

+Ns=600 //speen in rpm

+conductor_per_slot=8

+n=12 //slots per pole

+Slots=Pole*n 

+m=n/3 //slots per pole per phase 

+beeta=180/n //slot angle

+alpha=2*beeta  //short by 2 slots

+

+//flux per pole corresponding to 1st,3rd and 5th harmonic

+phi_1=100*10^-3

+phi_3=(33/100)*phi_1

+phi_5=(20/100)*phi_1

+

+//coil span factor corresponding to 1st,3rd and 5th harmonic

+K_c1=cosd( alpha/2)

+K_c3=cosd( 3*alpha/2)

+K_c5=cosd( 5*alpha/2)

+

+// using K_dx=sin(m*x*beeta /2) /(m*sin(x*beeta /2))

+//distribution factor corresponding to 1st,3rd and 5th harmonic

+K_d1=sind(m*1*beeta/2) /(m*sind(1*beeta /2))

+K_d3=sind(m*3*beeta/2) /(m*sind(3*beeta /2))

+K_d5=sind(m*5*beeta/2) /(m*sind(5*beeta /2))

+

+Z=conductor_per_slot*n*Pole    //Total Conductors

+Zph=Z/3 //conductors per phase

+T_ph=Zph/2 //turns per phase

+

+f=Ns*Pole/120

+E_1ph=4.44*K_c1*K_d1*phi_1*f*T_ph

+E_3ph=4.44*K_c3*K_d3*phi_3*f*T_ph

+E_5ph=4.44*K_c5*K_d5*phi_5*f*T_ph

+

+E_ph=sqrt( E_1ph^2 +  E_3ph^2 + E_5ph^2     )

+printf('Phase value of induced e.m.f is %.0f V ',E_ph)

+E_line=sqrt(3)*sqrt( E_1ph^2 +  E_5ph^2     )  //In a line value,3rd harmonic doesnt appear

+printf('\nline value of induced e.m.f is %.0f V ',E_line)

diff --git a/1938/CH4/EX4.17/4_17.sce b/1938/CH4/EX4.17/4_17.sce
new file mode 100755
index 000000000..2fbd61a45
--- /dev/null
+++ b/1938/CH4/EX4.17/4_17.sce
@@ -0,0 +1,34 @@
+clc,clear

+printf('Example 4.17\n\n')

+

+Pole=6

+Ns=1000 //speed in rpm

+d=28/100  //Divided by 100 to convert from centimeters to metres

+l=23/100  //Divided by 100 to convert from centimeters to metres

+m=4 //slots per pole per phase

+B_m1=0.87  //amplitude of 1st harmonic component of flux density

+B_m3=0.24  //amplitude of 3rd harmonic component of flux density

+Conductors_per_slot=8

+f=Ns*Pole/120 //frequency

+A1=%pi*d*l/Pole //area of each fundamental pole

+phi_1=(2/%pi)*A1*B_m1 //flux per pole in weber

+n=m*3 //slots per pole

+beeta=180/n //slot angle

+alpha=beeta  //because of 1 slot short

+K_c1=cosd(alpha/2) //coil span factor corresponding to 1st harmonic

+K_c3=cosd(3*alpha/2)//coil span factor corresponding to 3rd harmonic

+// using K_dx=sin(m*x*beeta*(%pi/180)/2) /(m*sin(x*beeta*(%pi/180)/2))

+K_d1=sind(m*1*beeta/2) /(m*sind(1*beeta/2)) //distribution factor corresponding to 1st harmonic

+K_d3=sind(m*3*beeta/2) /(m*sind(3*beeta/2)) //distribution factor corresponding to 3rd harmonic

+

+Slots=n*Pole

+Z=Slots*Conductors_per_slot //total number of conductors

+Z_ph=Z/3 //conductors per phase

+T_ph=Z_ph/2 //turns per phase

+

+E_1ph=4.44*K_c1*K_d1*phi_1*f*T_ph

+E_3ph=E_1ph* (B_m3*K_c3*K_d3)/(B_m1*K_c1*K_d1)      //using E_xph=E_1ph* (B_mx*K_cx*K_dx)/(B_m1*K_c1*K_d1)

+E_ph=sqrt( E_1ph^2 +  E_3ph^2     )

+printf('r.m.s value of resultant voltage is %.1f V',E_ph)

+E_line=sqrt(3)*E_1ph   //For line Value, 3rd harmonic does not appear

+printf('\nline voltage is %.3f V',E_line)

diff --git a/1938/CH4/EX4.18/4_18.sce b/1938/CH4/EX4.18/4_18.sce
new file mode 100755
index 000000000..c2b91553a
--- /dev/null
+++ b/1938/CH4/EX4.18/4_18.sce
@@ -0,0 +1,20 @@
+clc,clear

+printf('Example 4.18\n\n')

+

+V_L=125

+V_ph=V_L

+VA=600*10^3

+I_L=VA/(sqrt(3)*V_L)     // Because VA=sqrt(3)* V_L * I_L

+I_ph=I_L/(sqrt(3))

+

+//After Reconnection

+V_ph=125

+V_L=V_ph*sqrt(3)

+printf('New rating in volts is %.3f V',V_L)

+//Winding Impedances remain the same

+I_ph=1600

+I_L=I_ph

+

+printf('\nNew rating in amperes is %.0f A',I_L)

+kVA=sqrt(3)*V_L*I_L*(10^-3)

+printf('\nNew rating in kVA is %.0f kVA',kVA)

diff --git a/1938/CH4/EX4.19/4_19.sce b/1938/CH4/EX4.19/4_19.sce
new file mode 100755
index 000000000..8f6238b27
--- /dev/null
+++ b/1938/CH4/EX4.19/4_19.sce
@@ -0,0 +1,21 @@
+clc,clear

+printf('Example 4.19\n\n')

+

+Pole=4

+f=50 //frequency

+phi=0.12 //flux per pole in weber

+m=4  // slot per pole per phase

+conductor_per_slot=4

+coilspan=150

+Ns=120*f/Pole //synchronous speed in rpm

+n=m*3  //Slots per pole

+beeta=180/n //slot angle

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) // distribution factor

+alpha=180-coilspan //angle of short pitch

+K_c=cos((%pi/180)*alpha/2) //coil span factor

+Z=m*(n*Pole) // Also equal to (conductors/slots)*slots

+Z_ph=Z/3 //conductors per phase

+T_ph=Z_ph/2 //turns per phase

+E_ph=4.44*K_c*K_d*phi*f*T_ph

+E_line=sqrt(3)*E_ph

+printf('e.m.f generated is %.2f V(phase),%.2f V(line)',E_ph,E_line)

diff --git a/1938/CH4/EX4.2/4_2.sce b/1938/CH4/EX4.2/4_2.sce
new file mode 100755
index 000000000..70a3e9d17
--- /dev/null
+++ b/1938/CH4/EX4.2/4_2.sce
@@ -0,0 +1,11 @@
+clc,clear

+printf('Example 4.2\n\n')

+

+Slots=120

+Pole=8

+Phase=3 //number of phases

+n=Slots/Pole         //Slots per Pole

+m=Slots/Pole/Phase   //Slots per Pole per Phase

+beeta=180/n           //Slot angle in degree

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //Distribution Factor

+printf('Distribution Factor:\nK_d=%.3f',K_d)

diff --git a/1938/CH4/EX4.3/4_3.sce b/1938/CH4/EX4.3/4_3.sce
new file mode 100755
index 000000000..ee761fd17
--- /dev/null
+++ b/1938/CH4/EX4.3/4_3.sce
@@ -0,0 +1,13 @@
+clc,clear

+printf('Example 4.3\n\n')

+

+Slots=36

+Pole=4

+Phase=3 //number of phases

+n=Slots/Pole    //Slots per pole

+beeta=180/n     //Slot angle in degrees

+

+//coil is shorted by 1 slot i.e. by beeta degrees to full pitch distance

+alpha=beeta     //angle of short pitch

+K_c=cosd(alpha/2)  //Coil span Factor

+printf('Coil Span Factor:\nK_c=%.4f',K_c)

diff --git a/1938/CH4/EX4.4/4_4.sce b/1938/CH4/EX4.4/4_4.sce
new file mode 100755
index 000000000..524bdef24
--- /dev/null
+++ b/1938/CH4/EX4.4/4_4.sce
@@ -0,0 +1,23 @@
+clc,clear

+printf('Example 4.4\n\n')

+

+N_s=250  //Synchronous speed in r.p.m

+f=50     //Frequency of generated e.m.f in hertz

+Slots=216

+phi=30*10^-3 //flux per pole in weber

+

+Pole=120*f/N_s

+n=Slots/Pole   //Slots per Pole

+m=n/3          //Slots per Pole per Phase

+beeta=180/n     //Slot angle in degree

+

+K_d=sind(m*beeta/2)/(m*sind(beeta/2))   //distribution factor

+K_c=1 //Coil Span Factor for full pitch coils=1

+

+Z=Slots*5   //Z is total no of conductors

+Z_ph=Z/3    //Conductors Per Phase

+T_ph=Z_ph/2 //Turns per phase

+E_ph=4.44*K_c*K_d*f*phi*T_ph //induced emf

+E_line=E_ph*sqrt(3)

+

+printf('Induced e.m.f across the Terminals is %.2f V',E_line)

diff --git a/1938/CH4/EX4.5/4_5.sce b/1938/CH4/EX4.5/4_5.sce
new file mode 100755
index 000000000..cb0e6c5cf
--- /dev/null
+++ b/1938/CH4/EX4.5/4_5.sce
@@ -0,0 +1,24 @@
+clc,clear

+printf('Example 4.5\n\n')

+

+Pole=16

+N_s=375 //synchronous speed in rpm

+Slots=144

+E_line=2.657*10^3 //line value of emf across terminals

+f=Pole*N_s/120 //frequency

+

+K_c=1  //assuming full pitch winding,Coil span Factor=1

+n=Slots/Pole //slots per pole

+m=n/3 //slots per pole per phase

+

+beeta=180/n

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //Distribution Fcator

+conductors_per_slot=10

+Z=Slots*conductors_per_slot  //total conductors

+

+Z_ph=Z/3  //number of conductors per phase

+T_ph=Z_ph/2 //no of turns per phase

+E_ph=E_line/sqrt(3) //phase value of emf across terminals

+

+phi=E_ph/(4.44*K_c*K_d*f*T_ph)     //E_ph=4.44*K_c*K_d*f*phi*T_ph

+printf('Frequency of Induced e.m.f is %.0fHz\nFlux per Pole is %.0f mWb',f,phi*1000)

diff --git a/1938/CH4/EX4.6/4_6.sce b/1938/CH4/EX4.6/4_6.sce
new file mode 100755
index 000000000..f6e63dfe9
--- /dev/null
+++ b/1938/CH4/EX4.6/4_6.sce
@@ -0,0 +1,57 @@
+clc,clear

+printf('Example 4.6\n\n')

+

+d=0.25            //Diameter in metre

+l=0.3             //Length in metre

+Pole=4

+A1=%pi*d*l/Pole    //Area of each fundamental pole

+f=50 //frequency in hertz

+B_m1=0.15 , B_m3=0.03, B_m5=0.02 //Amplitude of 1st, 3rd and 5th harmonics

+phi_1=(2/%pi)*B_m1*A1  //average value of fundamental flux per pole in weber

+

+//PART A

+E_c1=1.11*2*f*phi_1  //R.M.S value of fundamental frequency e.m.f generated in single conductor

+Coil_span=(13/15)*180  //since winding coil span is 13/15 of pole pitch

+alpha=180-Coil_span

+

+//Pitch factor for 1st, 3rd and 5th harmonic

+K_c1=cosd(alpha/2)

+K_c3=cosd(3*alpha/2)

+K_c5=cosd(5*alpha/2)

+

+//Using E_cx=E_c1 * (B_mx/B_m1)

+E_c3=E_c1 * (B_m3/B_m1)

+E_c5=E_c1 * (B_m5/B_m1)

+

+E_t1=K_c1 * (2*E_c1)   //R.M.S Vaue of fundamental frequency EMF generated in 1 turn (in volts)

+E_t3=K_c3 * 2*E_c3

+E_t5=K_c5 * 2*E_c5

+E_t=sqrt(E_t1^2 +E_t3^2 +E_t5^2)

+V=10*E_t  //(number of turns per coil )* (Total e.m.f per turn)

+printf('Voltage generated per coil is %.1f V',V)

+

+// PART B

+//E_1ph=4.44*K_c1*K_d1*phi_1*f*T_ph

+T_ph=200   //T_ph=(60 coils  * 10 turns per coil)/3

+

+Total_Conductors=1200 // 60 coils * 10 turns per coil * 2

+Conductors_per_Slot=20 //2 conductors per turn * 10  turns per slot

+Slots=Total_Conductors/Conductors_per_Slot

+

+n=Slots/Pole

+m=n/3

+beeta=180/n   //Slot angle in degree

+K_d1=sind(m*1*beeta/2) /(m*sind(1*beeta/2))

+K_d3=sind(m*3*beeta/2) /(m*sind(3*beeta/2))

+K_d5=sind(m*5*beeta/2) /(m*sind(5*beeta/2))

+

+E_1ph=4.44 * K_c1 * K_d1*phi_1 * f * T_ph

+// Using E_xph= E_1ph* (B_mx*K_cx*K_dx)/(B_m1*K_c1*K_d1)

+E_3ph= E_1ph* (B_m3*K_c3*K_d3)/(B_m1*K_c1*K_d1)

+E_5ph= E_1ph* (B_m5*K_c5*K_d5)/(B_m1*K_c1*K_d1)

+E_ph=sqrt( E_1ph^2 + E_3ph^2 + E_5ph^2 )  //voltage generated per phase

+printf('\nVoltage generated per phase is %.0f V',E_ph)

+

+ //PART c

+E_line=sqrt(3) * sqrt( E_1ph^2 + E_5ph^2  ) //terminal voltage

+printf('\nTerminal Voltage is %.1f V ',E_line)

diff --git a/1938/CH4/EX4.7/4_7.sce b/1938/CH4/EX4.7/4_7.sce
new file mode 100755
index 000000000..f88178218
--- /dev/null
+++ b/1938/CH4/EX4.7/4_7.sce
@@ -0,0 +1,23 @@
+clc,clear

+printf('Example 4.7\n\n')

+

+Ns=250 //Synchronous speed in rpm

+f=50

+Slots=288

+E_line=6600

+Pole=120*f/Ns  

+n=Slots/Pole  //slots per pole

+m=n/3 //slots per pole per phase

+beeta=180/n //slot angle

+conductors_per_slot=32   //16 conductors per coil-side  *2 coil-sides per slot

+

+K_d=sind(m*beeta/2) /(m*sind(beeta/2)) //distribution factor

+alpha=2*beeta// angle of short pitch

+K_c=cosd(alpha/2)  //coil span factor

+Z = Slots*conductors_per_slot  //total conductors

+Z_ph=Z/3 //Conductors per phase

+T_ph=Z_ph/2 //turns per phase

+

+E_ph=E_line/sqrt(3)

+phi=E_ph/(4.44*K_c*K_d*f*T_ph)           //Because E_ph=4.44 *K_c *K_d *phi *f *T_ph

+printf('Flux per pole is %.0f mWb ',phi*1000)

diff --git a/1938/CH4/EX4.8/4_8.sce b/1938/CH4/EX4.8/4_8.sce
new file mode 100755
index 000000000..7f54cb405
--- /dev/null
+++ b/1938/CH4/EX4.8/4_8.sce
@@ -0,0 +1,27 @@
+clc,clear

+printf('Example 4.8\n\n')

+

+Ns=1500  //synchronous speed in rpm

+Pole=4

+Slots=24

+conductor_per_slot=8

+phi=0.05 //flux per pole in weber

+f=Pole*Ns/120 //frequenccy

+n=Slots/Pole //slots per pole

+m=n  // as number of phases is 1

+beeta=180/n  //slot angle

+

+K_d=sind(m*beeta/2) /(m*sind(beeta/2))  //distribution factor

+

+//Full pitch= n =6 slots

+//(1/6)th of full pitch =1slot

+//angle of short pitch = 1 slot angle

+alpha=beeta

+K_c=cosd(alpha/2)  //coil span factor

+

+Z=conductor_per_slot*Slots //total conductors

+Z_ph=Z // as number of phases is 1

+T_ph=Z_ph/2 //turns per phase

+E_ph=4.44*K_c*K_d* phi *f *T_ph  //induced emf

+

+printf('Induced e.m.f is %.1f V ',E_ph)

diff --git a/1938/CH4/EX4.9/4_9.sce b/1938/CH4/EX4.9/4_9.sce
new file mode 100755
index 000000000..c8fef19da
--- /dev/null
+++ b/1938/CH4/EX4.9/4_9.sce
@@ -0,0 +1,22 @@
+clc,clear

+printf('Example 4.9\n\n')

+

+Pole=48

+n=9 //slots per pole

+phi=51.75*10^-3 //flux per pole in weber

+Ns=125

+f=Ns*Pole/120 //frequency

+K_c=1 //due to full pitch winding

+m=n/3 //slots per pole per phase

+beeta=180/n  //slot angle

+

+K_d=sind(m*beeta/2) /(m*sind(beeta/2))  //distribution factor

+conductor_per_slot=4*2 //Each slot has 2 coil sides and each coil side has 4 conductors

+Slots=n*Pole

+Z=conductor_per_slot*Slots   //total number of conductors

+Z_ph=Z/3 //conductors per phase

+T_ph=Z_ph/2 //turns per phase

+E_ph=4.44 *K_c *K_d *phi *f *T_ph  //induced emf

+

+E_line=(sqrt(3))*E_ph  //due to star connection

+printf('Induced e.m.f is %.0f kV ',E_line/1000)