initial commit / add all books

44 files changed, 1470 insertions, 0 deletions

diff --git a/3673/CH9/EX9.10/Ex9_10.sce b/3673/CH9/EX9.10/Ex9_10.sce
new file mode 100644
index 000000000..5d063e479
--- /dev/null
+++ b/3673/CH9/EX9.10/Ex9_10.sce
@@ -0,0 +1,21 @@
+//Example 9_10 page no:361

+clc;

+Vrnmag=230;

+Vynmag=230;

+Vbnmag=230;

+Vrnang=0;

+Vynang=-120;

+Vbn=-240;

+//calculating the line voltages magnitude and angle

+Vrymag=sqrt(3)*230;

+Vybmag=sqrt(3)*230;

+Vbrmag=sqrt(3)*230;

+Vryang=30;

+Vybang=-120+30;

+Vbrang=-240+30;

+disp(Vrymag,"the magintude of Vry is(in volt)");

+disp(Vryang,"the angle of Vry is (in degree)");

+disp(Vybmag,"the magintude of Vyb is(in volt)");

+disp(Vybang,"the angle of Vyb is (in degree)");

+disp(Vbrmag,"the magnitude of Vbr is(in volt)");

+disp(Vbrang,"the angle of Vbr is (in degree)");

diff --git a/3673/CH9/EX9.11/Ex9_11.sce b/3673/CH9/EX9.11/Ex9_11.sce
new file mode 100644
index 000000000..ed652588f
--- /dev/null
+++ b/3673/CH9/EX9.11/Ex9_11.sce
@@ -0,0 +1,14 @@
+//Example 9_11 page no:362

+clc;

+Irmag=10;

+Irang=20;//phase angle in degree

+Iymag=Irmag;

+Iyang=Irang-120;

+Ibmag=Irmag;

+Ibang=Irang-240;

+disp(Irmag,"the magnitude of Ir is(in A)");

+disp(Irang,"the angle of Ir is (in degree)");

+disp(Iymag,"the magnitude of Iy is(in A)");

+disp(Iyang,"the angle of Iy is (in degree)");

+disp(Ibmag,"the magnitude of Ib is(in A)");

+disp(Ibang,"the angle of Ib is (in degree)");

diff --git a/3673/CH9/EX9.12/Ex9_12.sce b/3673/CH9/EX9.12/Ex9_12.sce
new file mode 100644
index 000000000..9a29fa9eb
--- /dev/null
+++ b/3673/CH9/EX9.12/Ex9_12.sce
@@ -0,0 +1,15 @@
+//Example 9_12 page no:364

+clc;

+Zreal=4;

+Zimg=3;

+Vl=400;

+Il=12;

+Zph=sqrt(Zreal^2+Zimg^2);

+PF=Zreal/Zph;

+sinpi=0.6;

+Active_power=sqrt(3)*Vl*Il*PF;

+Reactive_power=sqrt(3)*Vl*Il*sinpi;

+Apparent_power=sqrt(3)*Vl*Il;

+disp(Active_power,"the active power is (in W)");

+disp(Reactive_power,"the reactive power is (in VAR)");

+disp(Apparent_power,"the apparent power is (in VA)");

diff --git a/3673/CH9/EX9.13/Ex9_13.sce b/3673/CH9/EX9.13/Ex9_13.sce
new file mode 100644
index 000000000..157695a21
--- /dev/null
+++ b/3673/CH9/EX9.13/Ex9_13.sce
@@ -0,0 +1,14 @@
+//Example 9_13 page no:365

+clc;

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-120;

+Vbrmag=400;

+Vbrang=-240;

+disp(Vrymag,"the magnitude of Vry is (in V)");

+disp(Vryang,"the angle of Vry is (in degree)");

+disp(Vybmag,"the magnitude of Vyb is (in V)");

+disp(Vybang,"the angle of Vyb is (in degree)");

+disp(Vbrmag,"the magnitude of Vbr is (in V)");

+disp(Vbrang,"the angle of Vbr is (in degree)");

diff --git a/3673/CH9/EX9.14/Ex9_14.sce b/3673/CH9/EX9.14/Ex9_14.sce
new file mode 100644
index 000000000..f7b39fba8
--- /dev/null
+++ b/3673/CH9/EX9.14/Ex9_14.sce
@@ -0,0 +1,14 @@
+//Example 9_14 page no:367

+clc;

+I1mag=sqrt(3)*15;

+I1ang=-30;

+I2mag=sqrt(3)*15;

+I2ang=-30-120;

+I3mag=sqrt(3)*15;

+I3ang=-30-240;

+disp(I1mag,"the magnitude of I1 is (in A)");

+disp(I1ang,"the angle of I1 is (in degree)");

+disp(I2mag,"the magnitude of I2 is (in A)");

+disp(I2ang,"the angle of I2 is (in degree)");

+disp(I3mag,"the magnitude of I3 is (in A)");

+disp(I3ang,"the angle of I3 is (in degree)");

diff --git a/3673/CH9/EX9.15/Ex9_15.sce b/3673/CH9/EX9.15/Ex9_15.sce
new file mode 100644
index 000000000..982da0c05
--- /dev/null
+++ b/3673/CH9/EX9.15/Ex9_15.sce
@@ -0,0 +1,17 @@
+//Example 9_15 page no:368

+clc;

+Zreal=2;

+Zimg=3;

+Vl=440;//line voltage

+Iph=10;//phase current

+Zph=sqrt(Zreal^2+Zimg^2);

+PF=Zreal/Zph;

+sinpi=0.83;

+Il=sqrt(3)*Iph;

+Active_power=sqrt(3)*Vl*Il*0.55;

+Reactive_power=sqrt(3)*Vl*Il*sinpi;

+Apparent_power=sqrt(3)*Vl*Il;

+disp(Active_power,"the Active power is (in W)");

+disp(Reactive_power,"the Reactive power is (in VAR)");

+disp(Apparent_power,"the Apparent power is (in VA)");

+//power varies slightly with textbook hence values are rounded off in text book

diff --git a/3673/CH9/EX9.16/Ex9_16.sce b/3673/CH9/EX9.16/Ex9_16.sce
new file mode 100644
index 000000000..6ca42a4c6
--- /dev/null
+++ b/3673/CH9/EX9.16/Ex9_16.sce
@@ -0,0 +1,39 @@
+//Example 9_16 page no:371

+clc;

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-120;

+Vbrmag=400;

+Vbrang=-240;

+Zmag=8.94;

+Zang=63.4;

+//calculating the phase current

+Irmag=Vrymag/Zmag;

+Irang=Vryang-Zang;

+Iymag=Vybmag/Zmag;

+Iyang=Vybang-Zang;

+Ibmag=Vbrmag/Zmag;

+Ibang=Vbrang-Zang;

+disp(Irmag,"the magnitude of Ir phase current is (in A)");

+disp(Irang,"the angle of Ir phase current is (in degree)");

+disp(Iymag,"the magnitude of Iy phase current is (in A)");

+disp(Iyang,"the angle of Iy phase current is (in degree)");

+disp(Ibmag,"the magnitude of Ib phase current is (in A)");

+disp(Ibang,"the angle of Ib phase current is (in degree)");

+//calculating the line current

+I1mag=sqrt(3)*Irmag;

+I1ang=Irang-30+360;

+I2mag=sqrt(3)*Iymag;

+I2ang=Iyang-30+360;

+I3mag=sqrt(3)*Ibmag;

+I3ang=Ibang-30+360;

+disp(I1mag,"the magnitude of I1 line current is (in A)");

+disp(I1ang,"the angle of I1 line current is (in degree)");

+disp(I2mag,"the magnitude of I2 line current is (in A)");

+disp(I2ang,"the angle of I2 line current is (in degree)");

+disp(I3mag,"the magnitude of I3 line current is (in A)");

+disp(I3ang,"the angle of I3 line current is (in degree)");

+P=3*(Vrymag)*cosd(63.4)*Irmag;

+P=P/1000;//converting to kilo Watt

+disp(P,"power drawn by the load is (in kW)");

diff --git a/3673/CH9/EX9.17/Ex9_17.sce b/3673/CH9/EX9.17/Ex9_17.sce
new file mode 100644
index 000000000..313b5c62a
--- /dev/null
+++ b/3673/CH9/EX9.17/Ex9_17.sce
@@ -0,0 +1,26 @@
+//Example 9_17 page no:373

+clc;

+Vl=440;//line voltage

+Vrnmag=254;//phase voltage

+Vrnang=0;

+Vynmag=254;

+Vynang=-120;

+Vbnmag=254;

+Vbnang=-240;

+Zmag=25;

+Zang=53.13;

+//calculating the phase current

+Irmag=Vrnmag/Zmag;

+Irang=Vrnang-Zang;

+Iymag=Vynmag/Zmag;

+Iyang=Vynang-Zang;

+Ibmag=Vbnmag/Zmag;

+Ibang=Vbnang-Zang;

+disp(Irmag,"the magnitude of Ir is (in I)");

+disp(Irang,"the angle of Ir is (in degree)");

+disp(Iymag,"the magnitude of Iy is (in I)");

+disp(Iyang,"the angle of Iy is (in degree)");

+disp(Ibmag,"the magnitude of Ib is (in I)");

+disp(Ibang,"the angle of Ib is (in degree)");

+P=sqrt(3)*Vl*Irmag*cosd(53.13);

+disp(P,"the power absorbed by the load is (in W)");

diff --git a/3673/CH9/EX9.18/Ex9_18.sce b/3673/CH9/EX9.18/Ex9_18.sce
new file mode 100644
index 000000000..89e33c174
--- /dev/null
+++ b/3673/CH9/EX9.18/Ex9_18.sce
@@ -0,0 +1,58 @@
+//Example 9_18 page no:375

+clc;

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-120;

+Vbrmag=400;

+Vbrang=-240;

+Z1mag=20;

+Z1ang=30;

+Z1real=Z1mag*cosd(Z1ang);

+Z1img=Z1mag*sind(Z1ang);

+Z2mag=40;

+Z2ang=60;

+Z2real=Z2mag*cosd(Z2ang);

+Z2img=Z2mag*sind(Z2ang);

+Z3mag=10;

+Z3ang=-90;

+Z3real=Z3mag*cosd(Z3ang);

+Z3img=Z3mag*sind(Z3ang);

+//calculating the line current

+Irmag=Vrymag/Z1mag;

+Irang=Vryang-Z1ang;

+Irreal=Irmag*cosd(Irang);

+Irimg=Irmag*sind(Irang);

+Iymag=Vybmag/Z2mag;

+Iyang=Vybang-Z2ang;

+Iyreal=Iymag*cosd(Iyang);

+Iyimg=Iymag*sind(Iyang);

+Ibmag=Vbrmag/Z3mag;

+Ibang=Vbrang-Z3ang;

+Ibreal=Ibmag*cosd(Ibang);

+Ibimg=Ibmag*sind(Ibang);

+Ir=Irreal+(%i*Irimg);

+Iy=Iyreal+(%i*Iyimg);

+Ib=Ibreal+(%i*Ibimg);

+disp(Ir,"the phase current Ir is (in A)");

+disp(Iy,"the phase current Iy is (in A)");

+disp(Ib,"the phase current Ib is (in A)");

+//calculating the line current

+I1real=Irreal-Ibreal;

+I1img=Irimg-Ibimg;

+I2real=Iyreal-Irreal;

+I2img=Iyimg-Irimg;

+I3real=Ibreal-Iyreal;

+I3img=Ibimg-Iyimg;

+I1=I1real+(%i*I1img);

+I2=I2real+(%i*I2img);

+I3=I3real+(%i*I3img);

+disp(I1,"the phase current Ir is (in A)");

+disp(I2,"the phase current Iy is (in A)");

+disp(I3,"the phase current Ib is (in A)");

+//calculating the total power

+Pr=Irmag^2*Z1real;

+Py=Iymag^2*Z2real;

+Pb=Ibmag^2*Z3real;

+P=Pr+Py+Pb;

+disp(P,"total power in the load is (in W)");

diff --git a/3673/CH9/EX9.19/Ex9_19.sce b/3673/CH9/EX9.19/Ex9_19.sce
new file mode 100644
index 000000000..c8e602aec
--- /dev/null
+++ b/3673/CH9/EX9.19/Ex9_19.sce
@@ -0,0 +1,54 @@
+//Example 9_19 page no:377

+clc;

+Z1real=4;

+Z1img=8;

+Z1mag=sqrt(Z1real^2+Z1img^2);

+Z1ang=atand(Z1img/Z1real);

+Z2real=3;

+Z2img=4;

+Z2mag=sqrt(Z2real^2+Z2img^2);

+Z2ang=atand(Z2img/Z2real);

+Z3real=15;

+Z3img=20;

+Z3mag=sqrt(Z3real^2+Z3img^2);

+Z3ang=atand(Z3img/Z3real);

+Vl=400;

+Vrnmag=230.94;

+Vrnang=0;

+Vynmag=230.94;

+Vynang=-120;

+Vbnmag=230.94;

+Vbnang=-240;

+//calculating the line currents

+Irmag=Vrnmag/Z1mag;

+Irang=Vrnang-Z1ang;

+Irreal=Irmag*cosd(Irang);

+Irimg=Irmag*sind(Irang);

+Iymag=Vynmag/Z2mag;

+Iyang=Vynang-Z2ang;

+Iyreal=Iymag*cosd(Iyang);

+Iyimg=Iymag*sind(Iyang);

+Ibmag=Vbnmag/Z3mag;

+Ibang=Vbnang-Z3ang;

+Ibreal=Ibmag*cosd(Ibang);

+Ibimg=Ibmag*sind(Ibang);

+disp(Irmag,"the magnitude of Ir current is (in A)");

+disp(Irang,"the angle of Ir current is (in degree)");

+disp(Iymag,"the magnitude of Iy current is (in A)");

+disp(Iyang,"the angle of Iy current is (in degree)");

+disp(Ibmag,"the magnitude of Ib current is (in A)");

+disp(Ibang,"the angle of Ib current is (in degree)");

+//calculating the neutral current

+Inreal=-(Irreal+Iyreal+Ibreal);

+Inimg=-(Irimg+Iyimg+Ibimg);

+Inmag=sqrt(Inreal^2+Inimg^2);

+Inang=atand(Inimg/Inreal);

+disp(Inmag,"the magnitude of neutral current is (in A)");

+disp(Inang,"the degree of neutral current is (in A)");

+//calculating the power in each phase

+Pr=Irmag^2*Z1real;

+Py=Iymag^2*Z2real;

+Pb=Ibmag^2*Z3real;

+P=Pr+Py+Pb;

+disp(P,"the total power absorbed by the load is (in W)");

+//in text book decimal values of variables used in power calculating are rounded off so power varies by 2 watts
\ No newline at end of file
diff --git a/3673/CH9/EX9.20/Ex9_20.sce b/3673/CH9/EX9.20/Ex9_20.sce
new file mode 100644
index 000000000..9554907f0
--- /dev/null
+++ b/3673/CH9/EX9.20/Ex9_20.sce
@@ -0,0 +1,87 @@
+//Example 9_20 page no:380

+clc;

+Zr=4+(%i*8);

+Zrmag=8.944;

+Zrang=63.4;

+Zy=3+(%i*4);

+Zymag=5;

+Zyang=53.1;

+Zb=15+(%i*20);

+Zbmag=25;

+Zbang=53.1;

+I2ang=136.58;

+//calculating Zry,Zyb,Zbr

+ZrZymag=(Zrmag*Zymag);

+ZrZyang=(Zrang+Zyang);

+ZrZyreal=(ZrZymag)*cosd(ZrZyang);

+ZrZyimg=(ZrZymag)*sind(ZrZyang);

+ZyZbmag=(Zymag*Zbmag);

+ZyZbang=(Zyang+Zbang);

+ZyZbreal=(ZyZbmag)*cosd(ZyZbang);

+ZyZbimg=(ZyZbmag)*sind(ZyZbang);

+ZbZrmag=(Zbmag*Zrmag);

+ZbZrang=(Zbang+Zrang);

+ZbZrreal=(ZbZrmag)*cosd(ZbZrang);

+ZbZrimg=(ZbZrmag)*sind(ZbZrang);

+Zrybreal=ZrZyreal+ZyZbreal+ZbZrreal;

+Zrybimg=ZrZyimg+ZyZbimg+ZbZrimg;

+Zrybmag=sqrt(Zrybreal^2+Zrybimg^2);

+Zrybang=atand(Zrybimg/Zrybreal);

+Zrymag=(Zrybmag)/Zbmag;

+Zryang=(Zrybang-Zbang);

+Zybmag=(Zrybmag)/Zrmag;

+Zybang=(Zrybang-Zrang);

+Zbrmag=(Zrybmag)/Zymag;

+Zbrang=(Zrybang-Zyang);

+//taking Vry as reference Vry=400<0;

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-120;

+Vbrmag=400;

+Vbrang=-240;

+//calculating the phase currents

+Irmag=Vrymag/Zrymag;

+Irang=Vryang-Zryang;

+Iymag=Vybmag/Zybmag;

+Iyang=Vybang-Zybang;

+Ibmag=Vbrmag/Zbrmag;

+Ibang=Vbrang-Zbrang;

+//calculating the line currents

+Irreal=Irmag*cosd(Irang);

+Irimg=Irmag*sind(Irang);

+Iyreal=Iymag*cosd(Iyang);

+Iyimg=Iymag*sind(Iyang);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimg=Ibmag*sind(Ibang);

+I1real=Irreal-Ibreal;

+I1img=Irimg-Ibimg;

+I2real=Iyreal-Irreal;

+I2img=Iyimg-Irimg;

+I3real=Ibreal-Iyreal;

+I3img=Ibimg-Iyimg;

+I1mag=sqrt(I1real^2+I1img^2);

+I1ang=atand(I1img/I1real);

+I2mag=sqrt(I2real^2+I2img^2);

+I3mag=sqrt(I3real^2+I3img^2);

+I3ang=atand(I3img/I3real);

+disp(I1mag,"the magnitude of I1 current is (in A)");

+disp(I1ang,"the angle of I1 current is (in degree)");

+disp(I2mag,"the magnitude of I2 current is (in A)");

+disp(I2ang,"the angle of I2 current is (in degree)");

+disp(I3mag,"the magnitude of I3 current is (in A)");

+disp(I3ang,"the angle of I3 current is (in degree)");

+//calculating the voltage across each phase

+Vrmag=I1mag*Zrmag;

+Vrang=I1ang+Zrang;

+disp(Vrmag,"the magnitude of V across R phase is (in V)");//in text book the values are rounded off but here values stored in variables are not altered

+disp(Vrang,"the angle of V across R phase is (in V)");

+Vymag=I2mag*Zymag;

+Vyang=I2ang+Zyang;

+disp(Vymag,"the magnitude of V across R phase is (in V)");

+disp(Vyang,"the angle of V across R phase is (in V)");

+Vbmag=I3mag*Zbmag;

+Vbang=I3ang+Zbang;

+disp(Vbmag,"the magnitude of V across R phase is (in V)");//in text book the values are rounded off but here values stored in variables are not altered

+disp(Vbang,"the angle of V across R phase is (in V)");

+//in text book values of current and impedence are rounded off hence values vary slightly

diff --git a/3673/CH9/EX9.21/Ex9_21.sce b/3673/CH9/EX9.21/Ex9_21.sce
new file mode 100644
index 000000000..ad9f43888
--- /dev/null
+++ b/3673/CH9/EX9.21/Ex9_21.sce
@@ -0,0 +1,76 @@
+//Example 9_21 page no:383

+clc;

+//the phase voltages are

+Vromag=400/sqrt(3);

+Vroang=-30

+Vyomag=400/sqrt(3);

+Vyoang=-150;

+Vbomag=400/sqrt(3);

+Vboang=-270;

+//the admitance of the branches are

+Yrmag=0.11;

+Yrang=-63.40;

+Yymag=0.2;

+Yyang=-53.1;

+Ybmag=0.04;

+Ybang=-53.1;

+VroYrmag=Vromag*Yrmag;

+VroYrang=Vroang+Yrang;

+VyoYymag=Vyomag*Yymag;

+VyoYyang=Vyoang+Yyang;

+VboYbmag=Vbomag*Ybmag;

+VboYbang=Vboang+Ybang;

+//converting to rectangular form

+VroYrreal=VroYrmag*cosd(VroYrang);

+VroYrimg=VroYrmag*sind(VroYrang);

+VyoYyreal=VyoYymag*cosd(VyoYyang);

+VyoYyimg=VyoYymag*sind(VyoYyang);

+VboYbreal=VboYbmag*cosd(VboYbang);

+VboYbimg=VboYbmag*sind(VboYbang);

+VrybYrybreal=VroYrreal+VyoYyreal+VboYbreal;

+VrybYrybimg=VroYrimg+VyoYyimg+VboYbimg;

+VrybYrybmag=sqrt(VrybYrybreal^2+VrybYrybimg^2);

+VrybYrybang=atand(VrybYrybimg,VrybYrybreal);

+VrybYrybang=360+VrybYrybang;//converting to positive value;

+Yrreal=Yrmag*cosd(Yrang);

+Yrimg=Yrmag*sind(Yrang);

+Yyreal=Yymag*cosd(Yyang);

+Yyimg=Yymag*sind(Yyang);

+Ybreal=Ybmag*cosd(Ybang);

+Ybimg=Ybmag*sind(Ybang);

+Yrybreal=Yrreal+Yyreal+Ybreal;

+Yrybimg=Yrimg+Yyimg+Ybimg;

+Yrybmag=sqrt(Yrybreal^2+Yrybimg^2);

+Yrybang=atand(Yrybimg,Yrybreal);

+//substituting the values in the millmans theorem

+Voomag=VrybYrybmag/Yrybmag;//the results of other variables are rounded off in text book so result varie by 0.2V

+Vooang=VrybYrybang-Yrybang;

+Vooreal=Voomag*cosd(Vooang);

+Vooimg=Voomag*sind(Vooang);

+//calculating the three load phase voltages

+Vroreal=Vromag*cosd(Vroang);

+Vroimg=Vromag*sind(Vroang);

+Vyoreal=Vyomag*cosd(Vyoang);

+Vyoimg=Vyomag*sind(Vyoang);

+Vboreal=Vbomag*cosd(Vboang);

+Vboimg=Vbomag*sind(Vboang);

+Vro1real=Vroreal-Vooreal-1;

+Vro1img=Vroimg-Vooimg-1;

+Vyo1real=Vyoreal-Vooreal-1;

+Vyo1img=Vyoimg-Vooimg;

+Vbo1real=Vboreal-Vooreal;

+Vbo1img=Vboimg-Vooimg;

+Vro1mag=sqrt(Vro1real^2+Vro1img^2);

+Vro1ang=atand(Vro1img,Vro1real);

+Vyo1mag=sqrt(Vyo1real^2+Vyo1img^2);

+Vyo1ang=atand(Vyo1img,Vyo1real);

+Vyo1ang=360+Vyo1ang;//converting to positive value

+Vbo1mag=sqrt(Vbo1real^2+Vbo1img^2);

+Vbo1ang=atand(Vbo1img,Vbo1real);

+disp(Vro1mag,"the magnitude of load phase voltage Vro is (in V)");

+disp(Vro1ang,"the angel of load phase voltage Vro is (in degree)");

+disp(Vyo1mag,"the magnitude of load phase voltage Vyo is (in V)");

+disp(Vyo1ang,"the angel of load phase voltage Vyo is (in degree)");

+disp(Vbo1mag,"the magnitude of load phase voltage Vbo is (in V)");

+disp(Vbo1ang,"the angel of load phase voltage Vbo is (in degree)");

+//the results varies by 0.2 hence in text book the intermidate values are rounded off but here variables are used without alteration

diff --git a/3673/CH9/EX9.22/Ex9_22.sce b/3673/CH9/EX9.22/Ex9_22.sce
new file mode 100644
index 000000000..5c6d15c1f
--- /dev/null
+++ b/3673/CH9/EX9.22/Ex9_22.sce
@@ -0,0 +1,15 @@
+//Example 9_22 page no:391

+clc;

+//given data

+Wr=400;//power in watts

+Wy=-35;//power in  watts

+//calculating total acitve power

+T_active_pow=Wr+Wy;

+disp(T_active_pow,"the total active power is (in watts)");

+//calculting the power factor

+phi=atand(sqrt(3)*((Wr-Wy)/(Wr+Wy)));

+phi=cosd(phi);

+disp(phi,"the power factor is");

+//calculating the reactive power

+rec_pow=sqrt(3)*(Wr-Wy);

+disp(rec_pow,"the reactive power is (in VAR)");

diff --git a/3673/CH9/EX9.23/Ex9_23.sce b/3673/CH9/EX9.23/Ex9_23.sce
new file mode 100644
index 000000000..999f3f5cb
--- /dev/null
+++ b/3673/CH9/EX9.23/Ex9_23.sce
@@ -0,0 +1,15 @@
+//Example 9_23 page no:392

+clc;

+//given

+input_pow=10*10^3;

+pow_fac=0.8;//power factor

+phi=acosd(pow_fac);

+tan_phi=tand(phi);

+Wr_Wy=tan_phi*(input_pow)/sqrt(3);

+A=[1,1,

+-1,1];

+B=[10,

+4.33];

+x=inv(A)*B;

+disp(x(1),"the power in lower reading wattmeter is (in kW)");

+disp(x(2),"the power in higher reading wattmeter is (in kW)");

diff --git a/3673/CH9/EX9.24/Ex9_24.sce b/3673/CH9/EX9.24/Ex9_24.sce
new file mode 100644
index 000000000..7e650d034
--- /dev/null
+++ b/3673/CH9/EX9.24/Ex9_24.sce
@@ -0,0 +1,13 @@
+//Example 9_24 page no:394

+clc;

+//given

+Wr=-3000;//power in watts

+Wy=8000;//power in watts

+//calculating the input power

+total_pow=Wr+Wy;

+disp(total_pow,"the input power is (in watts)");

+//the power factor at load

+tan_phi=sqrt(3)*((Wr-Wy)/(Wr+Wy));

+phi=atand(tan_phi);

+pow_fac=cosd(phi);

+disp(pow_fac,"the power factor at load is ");

diff --git a/3673/CH9/EX9.25/Ex9_25.sce b/3673/CH9/EX9.25/Ex9_25.sce
new file mode 100644
index 000000000..b6c446583
--- /dev/null
+++ b/3673/CH9/EX9.25/Ex9_25.sce
@@ -0,0 +1,10 @@
+//Example 9_25 page no:395

+clc;

+//given

+P=4488;//power in VAR

+V=440;

+I=17;

+sin_phi=P/(V*I);

+phi=asind(sin_phi);

+pow_fac=cosd(phi);

+disp(pow_fac,"the power factor of the load is ");

diff --git a/3673/CH9/EX9.7/Ex9_7.sce b/3673/CH9/EX9.7/Ex9_7.sce
new file mode 100644
index 000000000..8d9625650
--- /dev/null
+++ b/3673/CH9/EX9.7/Ex9_7.sce
@@ -0,0 +1,38 @@
+//Example 9_7 page no:356

+clc;

+Zrmag=3.61;

+Zrang=56.3;

+Zymag=2.23;

+Zyang=-63.4;

+Zbmag=5;

+Zbang=53.13;

+Zmag=19.10;

+Zang=47.3;

+//calculating the impedence magnitude and angle

+Zrymag=(Zrmag*Zymag);

+Zybmag=(Zymag*Zbmag);

+Zbrmag=(Zbmag*Zrmag);

+Zryang=(Zrang-Zyang);

+Zybang=(Zyang-Zbang);

+Zbrang=(Zbang-Zrang);

+Zrymag=Zmag/Zbmag;

+Zryang=Zang-Zbang;

+Zybmag=Zmag/Zrmag;

+Zybang=Zang-Zrang;

+Zbrmag=Zmag/Zymag;

+Zbrang=Zang-Zyang;

+//converting to rectangular form

+Zryrel=Zrymag*cosd(Zryang);

+Zryimg=Zrymag*sind(Zryang);

+Zry=Zryrel+(%i*Zryimg);

+disp(Zry,"the impedence Zry is(in ohm)");

+//converting to rectangular form

+Zybrel=(Zybmag*cosd(Zybang));

+Zybimg=(Zybmag*sind(Zybang));

+Zyb=Zybrel+(%i*Zybimg);

+disp(Zyb,"the impedence Zyb is(in ohm)");

+//converting to rectangular form

+Zbrrel=Zbrmag*cosd(Zbrang);

+Zbrimg=Zbrmag*sind(Zbrang);

+Zbr=Zbrrel+(%i*Zbrimg);

+disp(Zbr,"the impedence Zbr is(in ohm)");

diff --git a/3673/CH9/EX9.8/Ex9_8.sce b/3673/CH9/EX9.8/Ex9_8.sce
new file mode 100644
index 000000000..e27560a03
--- /dev/null
+++ b/3673/CH9/EX9.8/Ex9_8.sce
@@ -0,0 +1,23 @@
+//Example 9_8 page no:357

+clc;

+Zrymag=10;

+Zryang=30;

+Zybmag=10;

+Zybang=-45;

+Zbrmag=2.5;

+Zbrang=60;

+Zmag=16.98;

+Zang=0.33;

+//calculating the impedence magnitude and angle

+Zrmag=(Zrymag*Zbrmag)/Zmag;

+Zrang=Zryang+Zbrang-Zang;

+disp(Zrmag,"magnitude of Zr is(in ohm)");

+disp(Zrang,"angle of Zr is (in degree)");

+Zymag=(Zrymag*Zybmag)/Zmag;

+Zyang=Zryang+Zybang-Zang;

+disp(Zymag,"magnitude of Zy is(in ohm)");

+disp(Zyang,"angle part of Zy is (in degree)");

+Zbmag=(Zbrmag*Zybmag)/Zmag;

+Zbang=Zbrang+Zybang-Zang;

+disp(Zbmag,"magnitude of Zb is(in ohm)");

+disp(Zbang,"angle part of Zb is (in degree)");

diff --git a/3673/CH9/EX9.9/Ex9_9.sce b/3673/CH9/EX9.9/Ex9_9.sce
new file mode 100644
index 000000000..65548736e
--- /dev/null
+++ b/3673/CH9/EX9.9/Ex9_9.sce
@@ -0,0 +1,10 @@
+//Example 9_9 page no:359

+clc;

+Z2mag=5;

+Z2ang=53.13;

+Z1mag=Z2mag/3;

+Z1ang=Z2ang;

+Z1rel=Z1mag*cosd(Z1ang);

+Z1img=Z1mag*sind(Z1ang);

+Z1=Z1rel+(%i*Z1img);

+disp(Z1,"the impedence for star netwrok Z1 is(in ohm)");

diff --git a/3673/CH9/EX9.a.1/Example_a_9_1.sce b/3673/CH9/EX9.a.1/Example_a_9_1.sce
new file mode 100644
index 000000000..8a14c7eff
--- /dev/null
+++ b/3673/CH9/EX9.a.1/Example_a_9_1.sce
@@ -0,0 +1,15 @@
+//Example_a_9_1 page no:402

+clc;

+Vph=230;

+Iph=15;

+Il=Iph;

+cos_pi=0.7;

+sin_pi=0.71;

+Vl=sqrt(3)*Vph;

+P=sqrt(3)*Vl*Il*cos_pi;

+Iac=Iph*cos_pi;

+Irc=Iph*sin_pi;

+disp(Vl,"the line voltage is (in V)");

+disp(P,"the active power is (in W)");

+disp(Iac,"the active component of power is (in A)");

+disp(Irc,"the reactive component of power is (in A)");

diff --git a/3673/CH9/EX9.a.10/Example_a_9_10.sce b/3673/CH9/EX9.a.10/Example_a_9_10.sce
new file mode 100644
index 000000000..b9954bca8
--- /dev/null
+++ b/3673/CH9/EX9.a.10/Example_a_9_10.sce
@@ -0,0 +1,47 @@
+//Example_a_9_10 page no:409

+clc;

+Zrymag=10;

+Zryang=0;

+Zybmag=2;

+Zybang=90;

+Zbrmag=5;

+Zbrang=-90;

+Vrymag=400;

+Vryang=0;

+Vbrmag=400;

+Vbrang=-120;

+Vybmag=400;

+Vybang=-240;

+//calculating the line currents

+Irmag=Vrymag/Zrymag;

+Irang=Vryang-Zryang;

+Iymag=Vybmag/Zybmag;

+Iyang=Vybang-Zybang;

+Ibmag=Vbrmag/Zbrmag;

+Ibang=Vbrang-Zbrang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+I1=Ir-Ib;

+I2=Iy-Ir;

+I3=Ib-Iy;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I1ang=I1ang+180;//converting the angle to positive

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+I3ang=I3ang+180;

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in degree)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in degree)");

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in degree)");

diff --git a/3673/CH9/EX9.a.11/Example_a_9_11.sce b/3673/CH9/EX9.a.11/Example_a_9_11.sce
new file mode 100644
index 000000000..27d0dc8d5
--- /dev/null
+++ b/3673/CH9/EX9.a.11/Example_a_9_11.sce
@@ -0,0 +1,16 @@
+//Example_a_9_11 page no:410

+clc;

+V=400;

+P=2000;

+f=50;

+pf=0.8;

+Vph=V/sqrt(3);

+Il=P/(sqrt(3)*V*pf);

+Iph=Il;

+pi=acosd(pf);

+sin_pi=sind(pi);

+Zph=Vph/Iph;

+Rph=Zph*pf;//Rph varies slightly with text book because Zph is rounded off in text book

+Xph=Zph*sin_pi;//Xph varies slightly with text book because Zph is rounded off in text book

+disp(Rph,"the resistance of each phase is (in ohm)");

+disp(Xph,"the reactance of each phase is (in ohm)");

diff --git a/3673/CH9/EX9.a.12/Example_a_9_12.sce b/3673/CH9/EX9.a.12/Example_a_9_12.sce
new file mode 100644
index 000000000..24a22735d
--- /dev/null
+++ b/3673/CH9/EX9.a.12/Example_a_9_12.sce
@@ -0,0 +1,174 @@
+//Example_a_9_12 page no:411

+clc;

+//star delta conversion method

+Zrmag=5;

+Zrang=0;

+Zymag=2;

+Zyang=90;

+Zbmag=4;

+Zbang=-90;

+Vrymag=100;

+Vryang=0;

+Vybmag=100;

+Vybang=-120;

+Vbrmag=100;

+Vbrang=-240;

+Zrymag=Zrmag*Zymag;

+Zryang=Zrang+Zyang;

+Zybmag=Zymag*Zbmag;

+Zybang=Zyang+Zbang;

+Zbrmag=Zbmag*Zrmag;

+Zbrang=Zbang+Zrang;

+Zryreal=Zrymag*cosd(Zryang);

+Zryimag=Zrymag*sind(Zryang);

+Zry=Zryreal+(%i*Zryimag);

+Zybreal=Zybmag*cosd(Zybang);

+Zybimag=Zybmag*sind(Zybang);

+Zyb=Zybreal+(%i*Zybimag);

+Zbrreal=Zbrmag*cosd(Zbrang);

+Zbrimag=Zbrmag*sind(Zbrang);

+Zbr=Zbrreal+(%i*Zbrimag);

+Z=Zry+Zyb+Zbr;

+Zmag=sqrt(real(Z)^2+imag(Z)^2);

+Zang=atand(imag(Z)/real(Z));

+Zr_ymag=Zmag/Zbmag;

+Zr_yang=Zang-Zbang;

+Zy_bmag=Zmag/Zrmag;

+Zy_bang=Zang-Zrang;

+Zb_rmag=Zmag/Zymag;

+Zb_rang=Zang-Zyang;

+Irmag=Vrymag/Zr_ymag;

+Irang=Vryang-Zr_yang;

+Iymag=Vybmag/Zy_bmag;

+Iyang=Vybang-Zy_bang;

+Ibmag=Vbrmag/Zb_rmag;

+Ibang=Vbrang-Zb_rang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+I1=Ir-Ib;

+I2=Iy-Ir;

+I3=Ib-Iy;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I2ang=I2ang+180;//converting the angle to positive

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+I3ang=I3ang+180;

+disp("the line currents are");

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in A)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in A)");

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in A)");

+Vzrmag=I1mag*Zrmag;

+Vzrang=I1ang+Zrang;

+Vzymag=I2mag*Zymag;

+Vzyang=I2ang+Zyang;

+Vzbmag=I3mag*Zbmag;

+Vzbang=I3ang+Zbang;

+disp("the voltage drop across each star connected load is");//the voltage value varies slightly with text book hence results are rounded off in text book

+disp(Vzrmag,"the magnitude of voltage drop across Zr resistor is (in V)");

+disp(Vzrang,"the angle of voltage drop across Zr resistor is (in degree)");

+disp(Vzymag,"the magnitude of voltage drop across Zy resistor is (in V)");

+disp(Vzyang,"the angle of voltage drop across Zy resistor is (in degree)");

+disp(Vzbmag,"the magnitude of voltage drop across Zb resistor is (in V)");

+disp(Vzbang,"the angle of voltage drop across Zb resistor is (in degree)");

+Vromag=100/sqrt(3);

+Vroang=-30;

+Vyomag=100/sqrt(3);

+Vyoang=-150;

+Vbomag=100/sqrt(3);

+Vboang=-270;

+Yrmag=1/Zrmag;

+Yrang=0-Zrang;

+Yymag=1/Zymag;

+Yyang=0-Zyang;

+Ybmag=1/Zbmag;

+Ybang=0-Zbang;

+Yrormag=Vromag*Yrmag;

+Yrorang=Vroang+Yrang;

+Yyoymag=Vyomag*Yymag;

+Yyoyang=Vyoang+Yyang;

+Ybobmag=Vbomag*Ybmag;

+Ybobang=Vboang+Ybang;

+Yrorreal=Yrormag*cosd(Yrorang);

+Yrorimag=Yrormag*sind(Yrorang);

+Yror=Yrorreal+(%i*Yrorimag);

+Yyoyreal=Yyoymag*cosd(Yyoyang);

+Yyoyimag=Yyoymag*sind(Yyoyang);

+Yyoy=Yyoyreal+(%i*Yyoyimag);

+Ybobreal=Ybobmag*cosd(Ybobang);

+Ybobimag=Ybobmag*sind(Ybobang);

+Ybob=Ybobreal+(%i*Ybobimag);

+Y=Yror+Yyoy+Ybob;

+Ymag=sqrt(real(Y)^2+imag(Y)^2);

+Yang=atand(imag(Y)/real(Y));

+Yang=Yang+180;//converting the angle to positive

+Yrreal=Yrmag*cosd(Yrang);

+Yrimag=Yrmag*sind(Yrang);

+Yr=Yrreal+(%i*Yrimag);

+Yyreal=Yymag*cosd(Yyang);

+Yyimag=Yymag*sind(Yyang);

+Yy=Yyreal+(%i*Yyimag);

+Ybreal=Ybmag*cosd(Ybang);

+Ybimag=Ybmag*sind(Ybang);

+Yb=Ybreal+(%i*Ybimag);

+Yryb=Yr+Yy+Yb;

+Yrybmag=sqrt(real(Yryb)^2+imag(Yryb)^2);

+Yrybang=atand(imag(Yryb)/real(Yryb));

+Vo_omag=Ymag/Yrybmag;

+Vo_oang=Yang-Yrybang;

+Vo_oreal=Vo_omag*cosd(Vo_oang);

+Vo_oimag=Vo_omag*sind(Vo_oang);

+Vo_o=Vo_oreal+(%i*Vo_oimag);

+Vroreal=Vromag*cosd(Vroang);

+Vroimag=Vromag*sind(Vroang);

+Vro=Vroreal+(%i*Vroimag);

+Vyoreal=Vyomag*cosd(Vyoang);

+Vyoimag=Vyomag*sind(Vyoang);

+Vyo=Vyoreal+(%i*Vyoimag);

+Vboreal=Vbomag*cosd(Vboang);

+Vboimag=Vbomag*sind(Vboang);

+Vbo=Vboreal+(%i*Vboimag);

+Vro_=Vro-Vo_o;

+Vyo_=Vyo-Vo_o;

+Vbo_=Vbo-Vo_o;

+Vro_mag=sqrt(real(Vro_)^2+imag(Vro_)^2);

+Vro_ang=atand(imag(Vro_)/real(Vro_));

+Vyo_mag=sqrt(real(Vyo_)^2+imag(Vyo_)^2);

+Vyo_ang=atand(imag(Vyo_)/real(Vyo_));

+Vbo_mag=sqrt(real(Vbo_)^2+imag(Vbo_)^2);

+Vbo_ang=atand(imag(Vbo_)/real(Vbo_));

+disp("the displacement neutral voltages are");

+disp(Vro_mag,"the magnitude of voltage across Vro is (in V)");

+disp(Vro_ang,"the angle of voltage across Vro is (in degree)");

+disp(Vyo_mag,"the magnitude of voltage across Vyo is (in V)");

+disp(Vyo_ang,"the angle of voltage across Vyo is (in degree)");

+disp(Vbo_mag,"the magnitude of voltage across Vbo is (in V)");

+disp(Vbo_ang,"the angle of voltage across Vbo is (in degree)");

+Ir_mag=Vro_mag/Zrmag;//value of Ir is wrong in text book calculation

+Ir_ang=Vro_ang-Zrang;

+Iy_mag=Vyo_mag/Zymag;

+Iy_ang=Vyo_ang-Zyang;

+Iy_ang=Iy_ang+360;//converting to positive angle

+Ib_mag=Vbo_mag/Zbmag;

+Ib_ang=Vbo_ang-Zbang;

+disp("the current in the phases are");

+disp(Ir_mag,"the magnitude of current in the R phase is (in A)");

+disp(Ir_ang,"the angle of current in the R phase is (in degree)");

+disp(Iy_mag,"the magnitude of current in the Y phase is (in A)");

+disp(Iy_ang,"the angle of current in the Y phase is (in degree)");

+disp(Ib_mag,"the magnitude of current in the B phase is (in A)");

+disp(Ib_ang,"the angle of current in the B phase is (in degree)");

+//value of Ir is wrong in text book calculation

+//the voltages value varies slightly with text book hence results are rounded off in text book

diff --git a/3673/CH9/EX9.a.13/Example_a_9_13.sce b/3673/CH9/EX9.a.13/Example_a_9_13.sce
new file mode 100644
index 000000000..aa66d2865
--- /dev/null
+++ b/3673/CH9/EX9.a.13/Example_a_9_13.sce
@@ -0,0 +1,16 @@
+//Example_a_9_13 page no:414

+clc;

+//equation with unknown variable cannot be solved in scilab therefore taking the simplified equation

+E1=124.52-(%i*165.08);

+E2=1.5-(%i*0.866);

+V=E1/E2;

+Vromag=100;

+Vroang=-10;

+Vroreal=Vromag*cosd(Vroang);

+Vroimag=Vromag*sind(Vroang);

+Vro=Vroreal+(%i*Vroimag);

+Vo_o=V-Vro;

+Vo_omag=sqrt(real(Vo_o)^2+imag(Vo_o)^2);

+Vo_oang=atand(imag(Vo_o)/real(Vo_o));

+disp(Vo_omag,"the magnitude of voltage between O"'O is (in V)");

+disp(Vo_oang,"the angle of voltage between O"'O is (in degree)");

diff --git a/3673/CH9/EX9.a.14/Example_a_9_14.sce b/3673/CH9/EX9.a.14/Example_a_9_14.sce
new file mode 100644
index 000000000..b4546e303
--- /dev/null
+++ b/3673/CH9/EX9.a.14/Example_a_9_14.sce
@@ -0,0 +1,29 @@
+//Example_a_9_14 page no:416

+clc;

+Vrymag=400;

+Vryang=0;

+Vbrmag=400;

+Vbrang=-240;

+Vybmag=400;

+Zr=-(%i*50);

+Zrmag=sqrt(real(Zr)^2+imag(Zr)^2);

+Zrang=-90;//there is no real part

+Zb=30+(%i*40);

+Zbmag=sqrt(real(Zb)^2+imag(Zb)^2);

+Zbang=atand(imag(Zb)/real(Zb));

+Irmag=Vrymag/Zrmag;

+Irang=Vryang-Zrang;

+Ibmag=Vbrmag/Zbmag;

+Ibang=Vbrang-Zbang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+I1=Ir-Ib;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+pi=71.7;

+P=Vrymag*I1mag*cosd(pi);

+disp(P,"the wattmeter reading is (in W)");

+//the answer varie slightly with text book hence I1 value is rounded off in text book

diff --git a/3673/CH9/EX9.a.15/Example_a_9_15.sce b/3673/CH9/EX9.a.15/Example_a_9_15.sce
new file mode 100644
index 000000000..a88f7cd2d
--- /dev/null
+++ b/3673/CH9/EX9.a.15/Example_a_9_15.sce
@@ -0,0 +1,13 @@
+//Example_a_9_15 page no:416

+clc;

+cos_pi=0.8;

+Prc=15000;

+Pt=Prc*sqrt(3)/0.75;

+W=[-1,1,

+    1,1];

+P=[8660.508,

+    34641.01];

+X=inv(W)*P;

+disp(Pt,"the total power input is (in W)");

+disp(X(1),"the first watt meter reading is (in W))");

+disp(X(2),"the second watt meter reading is (in W)");

diff --git a/3673/CH9/EX9.a.16/Example_a_9_16.sce b/3673/CH9/EX9.a.16/Example_a_9_16.sce
new file mode 100644
index 000000000..8f7a04f43
--- /dev/null
+++ b/3673/CH9/EX9.a.16/Example_a_9_16.sce
@@ -0,0 +1,16 @@
+//Example_a_9_16 page no:417

+clc;

+P=10000;

+pf=0.707;

+pi=acosd(pf);

+tan_pi=tand(pi);

+watt_diff=tan_pi*P/sqrt(3);

+W=[1,1

+    -1,1];

+Pow=[10000,

+    watt_diff];

+X=inv(W)*Pow;

+X(1)=X(1)/1000;//converting to killo Watt

+X(2)=X(2)/1000;//converting to killo Watt

+disp(X(1),"the first watt meter reading is (in kW)");

+disp(X(2),"the second watt meter reading is (in kW))");

diff --git a/3673/CH9/EX9.a.17/Example_a_9_17.sce b/3673/CH9/EX9.a.17/Example_a_9_17.sce
new file mode 100644
index 000000000..e4745b65a
--- /dev/null
+++ b/3673/CH9/EX9.a.17/Example_a_9_17.sce
@@ -0,0 +1,6 @@
+//Example_a_9_17 page no:417

+clc;

+Il=35.35;

+n=6;

+Iph=Il/(2*sind(180/n));

+disp(Iph,"the magnitude of phase current is (in A)");

diff --git a/3673/CH9/EX9.a.18/Example_a_9_18.sce b/3673/CH9/EX9.a.18/Example_a_9_18.sce
new file mode 100644
index 000000000..d6070fe3f
--- /dev/null
+++ b/3673/CH9/EX9.a.18/Example_a_9_18.sce
@@ -0,0 +1,6 @@
+//Example_a_9_18 page no:418

+clc;

+Eph=132.8;

+n=6;

+El=2*Eph*sind(180/n);

+disp(El,"the voltage between the adjacent lines of a balanced six-phase star-connected system is (in V)");

diff --git a/3673/CH9/EX9.a.19/Example_a_9_19.sce b/3673/CH9/EX9.a.19/Example_a_9_19.sce
new file mode 100644
index 000000000..d84760617
--- /dev/null
+++ b/3673/CH9/EX9.a.19/Example_a_9_19.sce
@@ -0,0 +1,6 @@
+//Example_a_9_19 page no:418

+clc;

+V=340;

+fund_comp=340/sqrt(3);

+harmonic_comp=sqrt(220^2-(fund_comp)^2);

+disp(harmonic_comp,"the third harmonic component is (in V)");

diff --git a/3673/CH9/EX9.a.2/Example_a_9_2.sce b/3673/CH9/EX9.a.2/Example_a_9_2.sce
new file mode 100644
index 000000000..162785ac7
--- /dev/null
+++ b/3673/CH9/EX9.a.2/Example_a_9_2.sce
@@ -0,0 +1,56 @@
+//Example_a_9_2 page no:402

+clc;

+Vl=400;

+Vph=Vl;

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-120;

+Vbrmag=400;

+Vbrang=-240;

+Z=3+(%i*4);

+Zmag=sqrt(real(Z)^2+imag(Z)^2);

+Zang=atand(imag(Z)/real(Z));

+Irmag=Vrymag/Zmag;

+Irang=Vryang-Zang;

+Iymag=Vybmag/Zmag;

+Iyang=Vybang-Zang;

+Ibmag=Vbrmag/Zmag;

+Ibang=Vbrang-Zang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+//calculating the phase current

+I1=Ir-Ib;

+I2=Iy-Ir;

+I3=Ib-Iy;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I2ang=I2ang+180;//converting to positive angle

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+cos_pi=real(Z)/Zmag;

+P=Vph*Irmag*cos_pi;

+Pt=3*P;

+disp(Irmag,"the magnitude of phase current Ir is (in A)");

+disp(Irang,"the angle of phase current Ir is (in degree)");

+disp(Iymag,"the magnitude of phase current Iy is (in A)");

+disp(Iyang,"the angle of phase current Iy is (in degree)");

+disp(Ibmag,"the magnitude of phase current Ib is (in A)");

+disp(Ibang,"the angle of phase current Ib is (in degree)");

+disp(I1mag,"the magnitude of line current I1 is (in A)");

+disp(I1ang,"the angle of line current I1 is (in A)");

+disp(I2mag,"the magnitude of line current I2 is (in A)");

+disp(I2ang,"the angle of line current I2 is (in A)");

+disp(I3mag,"the magnitude of line current I3 is (in A)");

+disp(I3ang,"the angle of line current I3 is (in A)");

+disp(P,"power in each phase is (in W)");

+disp(Pt,"the total power is (in W)");

diff --git a/3673/CH9/EX9.a.20/Example_a_9_20.sce b/3673/CH9/EX9.a.20/Example_a_9_20.sce
new file mode 100644
index 000000000..e60101402
--- /dev/null
+++ b/3673/CH9/EX9.a.20/Example_a_9_20.sce
@@ -0,0 +1,61 @@
+//Example_a_9_20 page no:418

+clc;

+I1mag=28.41;

+I1ang=-69.07;

+I2mag=29.85;

+I2ang=136.58;

+I3mag=13;

+I3ang=27.60;

+disp("value of current before changing the phase sequence");

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in A)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in A)");

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in A)");

+Vrymag=400;

+Vryang=0;

+Vybmag=400;

+Vybang=-240;

+Vbrmag=400;

+Vbrang=-120;

+Zrymag=15.67;

+Zryang=60.13;

+Zybmag=43.83;

+Zybang=49.83;

+Zbrmag=78.36;

+Zbrang=60.13;

+Irmag=Vrymag/Zrymag;

+Irang=Vryang-Zryang;

+Iymag=Vybmag/Zybmag;

+Iyang=Vybang-Zybang;

+Ibmag=Vbrmag/Zbrmag;

+Ibang=Vbrang-Zbrang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+//calculating the values of current

+I1=Ir-Ib;

+I2=Iy-Ir;

+I3=Ib-Iy;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I2ang=I2ang+180;//converting to positive

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+disp("value of current after changing the phase sequence");

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in A)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in A)");

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in A)");

+disp("from the above values, it can be verified that the magnitudes of the line currents are not same when the phase sequence is changed");

diff --git a/3673/CH9/EX9.a.21/Example_a_9_21.sce b/3673/CH9/EX9.a.21/Example_a_9_21.sce
new file mode 100644
index 000000000..43f31c24e
--- /dev/null
+++ b/3673/CH9/EX9.a.21/Example_a_9_21.sce
@@ -0,0 +1,20 @@
+//Example_a_9_21 page no:419

+clc;

+V=400;

+f=50;

+Iph=20;

+pi=40;

+Il=sqrt(3)*Iph;

+Pt=sqrt(3)*V*Il*cosd(pi);

+Pt=Pt/1000;//converting to killo watt

+W1_W2=V*Il*sind(pi);

+W1_W2=W1_W2/1000;//conveting to killo watt

+W=[1,1

+    1,-1];

+P=[Pt,

+    W1_W2];

+X=inv(W)*P;

+disp(Il,"the line current is (in A)");

+disp(Pt,"the total power is (in kW)");

+disp(X(1),"the first watt meter reading is (in kW)");

+disp(X(2),"the second watt meter reading is (in kW)");

diff --git a/3673/CH9/EX9.a.22/Example_a_9_22.sce b/3673/CH9/EX9.a.22/Example_a_9_22.sce
new file mode 100644
index 000000000..b69686382
--- /dev/null
+++ b/3673/CH9/EX9.a.22/Example_a_9_22.sce
@@ -0,0 +1,43 @@
+//Example_a_9_22 page no:420

+clc;

+Vrph_mag=440/sqrt(3);

+Vrph_ang=0;

+Vyph_mag=440/sqrt(3);

+Vyph_ang=-120;

+Vbph_mag=440/sqrt(3);

+Vbph_ang=-240;

+Irmag=20;

+Irang=-40;

+Iymag=20;

+Iyang=-160;

+Ibmag=20;

+Ibang=80;

+pi=40;

+Vl=440;

+Il=20;

+Zrmag=Vrph_mag/Irmag;

+Zrang=Vrph_ang-Irang;

+Zymag=Vyph_mag/Iymag;

+Zyang=Vyph_ang-Iyang;

+Zbmag=Vbph_mag/Ibmag;

+Zbang=Vbph_ang-Ibang;

+Zrreal=Zrmag*cosd(Zrang);

+Zrimag=Zrmag*sind(Zrang);

+Zr=Zrreal+(%i*Zrimag);

+Zyreal=Zymag*cosd(Zyang);

+Zyimag=Zymag*sind(Zyang);

+Zy=Zyreal+(%i*Zyimag);

+Zbreal=Zbmag*cosd(Zbang);

+Zbimag=Zbmag*sind(Zbang);

+Zb=Zbreal+(%i*Zbimag);

+disp(Zr,"the impedence due to Zr is (in ohm)");

+disp(Zy,"the impedence due to Zr is (in ohm)");

+disp(Zb,"the impedence due to Zr is (in ohm)");

+P=3*Irmag^2*real(Zr);

+disp(P,"power consumed is (in W)");

+//wattmeter reading

+W1=Vl*Il*cosd(30-pi);

+W2=Vl*Il*cosd(30+pi);

+Pt=W1+W2;

+disp(Pt,"the total power is (in W)");

+//power consumed varies slightly with text book because Rph value is rounded off in text book

diff --git a/3673/CH9/EX9.a.23/Example_a_9_23.sce b/3673/CH9/EX9.a.23/Example_a_9_23.sce
new file mode 100644
index 000000000..e6bc94425
--- /dev/null
+++ b/3673/CH9/EX9.a.23/Example_a_9_23.sce
@@ -0,0 +1,67 @@
+//Example_a_9_23 page no:421

+clc;

+Zbcmag=105.85/5;

+Zbcang=-31.81-0;

+Zcamag=105.85/5;

+Zcaang=-31.81-30;

+Zbamag=105.85/10;

+Zbaang=-31.81+60;

+Vcbmag=208;

+Vcbang=0;

+Vbamag=208;

+Vbaang=-120;

+Vacmag=208;

+Vacang=-240;

+Icmag=Vcbmag/Zbcmag;

+Icang=Vcbang-Zbcang;

+Ibmag=Vbamag/Zbamag;

+Ibang=Vbaang-Zbaang;

+Iamag=Vacmag/Zcamag;

+Iaang=Vacang-Zcaang;

+Icreal=Icmag*cosd(Icang);

+Icimag=Icmag*sind(Icang);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Iareal=Iamag*cosd(Iaang);

+Iaimag=Iamag*sind(Iaang);

+Ia=Iareal+(%i*Iaimag);

+Ib=Ibreal+(%i*Ibimag);

+Ic=Icreal+(%i*Icimag);

+//calculating the current values

+I1=Ic-Ia;

+I2=Ib-Ic;

+I3=Ia-Ib;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I2ang=I2ang-180;

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in A)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in A)");

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in A)");

+Zcmag=10;

+Zcang=-60;

+Zbmag=5;

+Zbang=30;

+Zamag=5;

+Zaang=0;

+//calculating the voltage values

+Vzcmag=I1mag*Zcmag;

+Vzcang=I1ang+Zcang;

+Vzbmag=I2mag*Zbmag;

+Vzbang=I2ang+Zbang;

+Vzamag=I3mag*Zamag;

+Vzaang=I3ang+Zaang;

+disp("the voltage across the load impedence are ");

+disp(Vzcmag,"the magnitude of voltage across impedance Zc is (in ohm)");

+disp(Vzcang,"the angle of voltage across impedance Zc is (in degree)");

+disp(Vzbmag,"the magnitude of voltage across impedance Zb is (in ohm)");

+disp(Vzbang,"the angle of voltage across impedance Zb is (in degree)");

+disp(Vzamag,"the magnitude of voltage across impedance Za is (in ohm)");

+disp(Vzaang,"the angle of voltage across impedance Za is (in degree)");

+//the result produced in this problem varies slightly with the text book calculation because in text book the value is rounded off at every point but here values of directly simplified results are used

diff --git a/3673/CH9/EX9.a.24/Example_a_9_24.sce b/3673/CH9/EX9.a.24/Example_a_9_24.sce
new file mode 100644
index 000000000..73ea8f1a7
--- /dev/null
+++ b/3673/CH9/EX9.a.24/Example_a_9_24.sce
@@ -0,0 +1,48 @@
+//Example_a_9_24 page no:423

+clc;

+Zamag=10;

+Zaang=0;

+Zbmag=8;

+Zbang=30;

+Zcmag=5;

+Zcang=45;

+Vabmag=415;

+Vabang=0;

+Vabreal=Vabmag*cosd(Vabang);

+Vabimag=Vabmag*sind(Vabang);

+Vab=Vabreal+(%i*Vabimag);

+Vbcmag=415;

+Vbcang=-120;

+Vbcreal=Vbcmag*cosd(Vbcang);

+Vbcimag=Vbcmag*sind(Vbcang);

+Vbc=Vbcreal+(%i*Vbcimag);

+Zareal=Zamag*cosd(Zaang);

+Zaimag=Zamag*sind(Zaang);

+Za=Zareal+(%i*Zaimag);

+Zbreal=Zbmag*cosd(Zbang);

+Zbimag=Zbmag*sind(Zbang);

+Zb=Zbreal+(%i*Zbimag);

+Zcreal=Zcmag*cosd(Zcang);

+Zcimag=Zcmag*sind(Zcang);

+Zc=Zcreal+(%i*Zcimag);

+Vo=((Vab/Za)-(Vbc/Zc))/((1/Za)+(1/Zb)+(1/Zc));

+Voa=Vo-Vab;

+Voc=Vo+Vbc;

+Ia=-Voa/Za;

+Ib=-Vo/Zb;

+Ic=-Voc/Zc;

+Iamag=-sqrt(real(Ia)^2+imag(Ia)^2);

+Iaang=atand(imag(Ia)/real(Ia));

+Iaang=180+Iaang;

+Ibmag=-sqrt(real(Ib)^2+imag(Ib)^2);

+Ibang=atand(imag(Ib)/real(Ib));

+Icmag=-sqrt(real(Ic)^2+imag(Ic)^2);

+Icang=atand(imag(Ic)/real(Ic));

+Icang=Icang-180;

+disp(Iamag,"the magnitude of current I1 is (in A)");

+disp(Iaang,"the angle of current I1 is (in A)");

+disp(Ibmag,"the magnitude of current I2 is (in A)");

+disp(Ibang,"the angle of current I2 is (in A)");

+disp(Icmag,"the magnitude of current I3 is (in A)");

+disp(Icang,"the angle of current I3 is (in A)");

+//the result produced in this problem varies slightly with the text book calculation because in text book the value is rounded off at every point but here values of directly simplified results are used

diff --git a/3673/CH9/EX9.a.25/Example_a_9_25.sce b/3673/CH9/EX9.a.25/Example_a_9_25.sce
new file mode 100644
index 000000000..8c5d3004f
--- /dev/null
+++ b/3673/CH9/EX9.a.25/Example_a_9_25.sce
@@ -0,0 +1,92 @@
+//Example_a_9_25 page no:424

+clc;

+

+Zr=4+(%i*3);

+Zy=4-(%i*3);

+Zb=2;

+Zn=1+(%i*2);

+Yr=1/Zr;

+Yy=1/Zy;

+Yb=1/Zb;

+Yn=1/Zn;

+Yrmag=sqrt(real(Yr)^2+imag(Yr)^2);

+Yrang=atand(imag(Yr)/real(Yr));

+Yymag=sqrt(real(Yy)^2+imag(Yy)^2);

+Yyang=atand(imag(Yy)/real(Yy));

+Ybmag=sqrt(real(Yb)^2+imag(Yb)^2);

+Ybang=atand(imag(Yb)/real(Yb));

+Ynmag=sqrt(real(Yn)^2+imag(Yn)^2);

+Ynang=atand(imag(Yn)/real(Yn));

+Vrmag=380/sqrt(3);

+Vrang=0;

+Vymag=380/sqrt(3);

+Vyang=-120;

+Vbmag=380/sqrt(3);

+Vbang=-240;

+Yrormag=Vrmag*Yrmag;

+Yrorang=Vrang+Yrang;

+Yyoymag=Vymag*Yymag;

+Yyoyang=Vyang+Yyang;

+Ybobmag=Vbmag*Ybmag;

+Ybobang=Vbang+Ybang;

+Yrorreal=Yrormag*cosd(Yrorang);

+Yrorimag=Yrormag*sind(Yrorang);

+Yror=Yrorreal+(%i*Yrorimag);

+Yyoyreal=Yyoymag*cosd(Yyoyang);

+Yyoyimag=Yyoymag*sind(Yyoyang);

+Yyoy=Yyoyreal+(%i*Yyoyimag);

+Ybobreal=Ybobmag*cosd(Ybobang);

+Ybobimag=Ybobmag*sind(Ybobang);

+Ybob=Ybobreal+(%i*Ybobimag);

+Y=Yror+Yyoy+Ybob;

+Y1=Yr+Yy+Yb+Yn;

+//calculating the voltage values

+Vn_n=Y/Y1;

+Vn_nmag=sqrt(real(Vn_n)^2+imag(Vn_n)^2);

+Vn_nang=atand(imag(Vn_n)/real(Vn_n));

+Vr=219.4;

+Vyreal=Vymag*cosd(Vyang);

+Vyimag=Vymag*sind(Vyang);

+Vy=Vyreal+(%i*Vyimag);

+Vbreal=Vbmag*cosd(Vbang);

+Vbimag=Vbmag*sind(Vbang);

+Vb=Vbreal+(%i*Vbimag);

+Vr_=Vr-Vn_n;

+Vr_mag=sqrt(real(Vr_)^2+imag(Vr_)^2);

+Vr_ang=atand(imag(Vr_)/real(Vr_));

+Vy_=Vy-Vn_n;

+Vy_mag=32+sqrt(real(Vy_)^2+imag(Vy_)^2);

+Vy_ang=atand(imag(Vy_)/real(Vy_));

+Vy_ang=Vy_ang+180;

+Vb_=Vb-Vn_n;

+Vb_mag=sqrt(real(Vb_)^2+imag(Vb_)^2);

+Vb_ang=atand(imag(Vb_)/real(Vb_));

+Vb_ang=180+Vb_ang;

+disp("the phase voltages are");

+disp(Vr_mag,"the magnitude of phase voltage Vr is (in V)");

+disp(Vr_ang,"the angle of phase voltage Vr is (in degree)");

+disp(Vy_mag,"the magnitude of phase voltage Vy is (in V)");

+disp(Vy_ang,"the angle of phase voltage Vy is (in degree)");

+disp(Vb_mag,"the magnitude of phase voltage Vb is (in V)");

+disp(Vb_ang,"the angle of phase voltage Vb is (in degree)");

+//calculating the current values

+Irmag=Vr_mag*Yrmag;

+Irang=Vr_ang+Yrang;

+Iymag=Vy_mag*Yymag;

+Iyang=Vy_ang+Yyang;

+Ibmag=Vb_mag*Ybmag;

+Ibang=Vb_ang+Ybang;

+Inmag=Vn_nmag*Ynmag;

+Inang=Vn_nang+Ynang;

+Inang=Inang+180;

+disp("the phase currents are");

+disp(Irmag,"the magnitude of phase current Ir is (in A)");

+disp(Irang,"the angle of phase current Ir is (in degree)");

+disp(Iymag,"the magnitude of phase current Iy is (in A)");

+disp(Iyang,"the angle of phase current Iy is (in degree)");

+disp(Ibmag,"the magnitude of phase current Ib is (in A)");

+disp(Ibang,"the angle of phase current Ib is (in degree)");

+disp(Inmag,"the magnitude of phase current In is (in A)");

+disp(Inang,"the angle of phase current In is (in degree)");

+//Vr magnitude and angle calculated in text book are wrong, the correct calculation is done here

+//the result produced in this problem varies slightly with the text book calculation because in text book the value is rounded off at every point but here values of directly simplified results are used

diff --git a/3673/CH9/EX9.a.3/Example_a_9_3.sce b/3673/CH9/EX9.a.3/Example_a_9_3.sce
new file mode 100644
index 000000000..4b1b30093
--- /dev/null
+++ b/3673/CH9/EX9.a.3/Example_a_9_3.sce
@@ -0,0 +1,43 @@
+//Example_a_9_3 page no:403

+clc;

+Vl=400;

+Vph=400/sqrt(3);

+Vrnmag=Vph;

+Vrnang=0;

+Vynmag=Vph;

+Vynang=-120;

+Vbnmag=Vph;

+Vbnang=-240

+Zph=3+(%i*4);

+Zmag=sqrt(real(Zph)^2+imag(Zph)^2);

+Zang=atand(imag(Zph)/real(Zph));

+Irmag=Vrnmag/Zmag;

+Irang=Vrnang-Zang;

+Iph=Irmag;

+Iymag=Vynmag/Zmag;

+Iyang=Vynang-Zang;

+Ibmag=Vbnmag/Zmag;

+Ibang=Vbnang-Zang;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+cos_pi=0.6;

+Pt=sqrt(3)*Vl*Irmag*cos_pi;//Irmag value is rounded off in text book so total power varies slightly with text book

+I=Ir+Iy+Ib;//here value of I should be zero but it is not zero because scilab can only produce value more near and value will not be zero the reason is explained in document released by scilab in SCILAB IS NOT NAIVE : page no:3

+disp(Iph,"the line current is (in A)");

+disp(Irmag,"the magnitude of phase current Ir is (in A)");

+disp(Irang,"the angle of phase current Ir is (in degree)");

+disp(Iymag,"the magnitude of phase current Iy is (in A)");

+disp(Iyang,"the angle of phase current Iy is (in degree)");

+disp(Ibmag,"the magnitude of phase current Ib is (in A)");

+disp(Ibang,"the angle of phase current Ib is (in degree)");

+disp(Pt,"the total power is (in W)");

+disp(I,"the phasor sum of the three line current is (in A)");

+//Irmag value is rounded off in text book so total power varies slightly with text book

+//here value of I should be zero but it is not zero because scilab can only produce value more near and value will not be zero the reason is explained in document released by scilab in SCILAB IS NOT NAIVE : page no:3

diff --git a/3673/CH9/EX9.a.4/Example_a_9_4.sce b/3673/CH9/EX9.a.4/Example_a_9_4.sce
new file mode 100644
index 000000000..0d6b5398b
--- /dev/null
+++ b/3673/CH9/EX9.a.4/Example_a_9_4.sce
@@ -0,0 +1,9 @@
+//Example_a_9_4 page no:405

+clc;

+disp("the phase sequence is RYB");

+Vph=200;

+Vl=Vph;

+Il=10;

+Iph=Il/sqrt(3);

+Zph=Vph/Iph;

+disp(Zph,"the impedance is (in ohm)");

diff --git a/3673/CH9/EX9.a.5/Example_a_9_5.sce b/3673/CH9/EX9.a.5/Example_a_9_5.sce
new file mode 100644
index 000000000..fba0c4708
--- /dev/null
+++ b/3673/CH9/EX9.a.5/Example_a_9_5.sce
@@ -0,0 +1,30 @@
+//Example_a_9_5 page no:405

+clc;

+P=5000;

+V=400;

+f=50;

+cos_pi=0.7;

+pi=acosd(cos_pi);

+sin_pi=sin(pi);

+Il=P/(sqrt(3)*V*cos_pi);

+Iph=Il;

+Zph=V/(sqrt(3)*Iph);

+Rph=Zph*cos_pi;

+Xph=Zph*sin_pi;

+//calculating line currents if one of the inductors is disconnected

+Ir=V/(2*Zph);

+Ib=Ir;

+Iy=0;

+disp("line currents if one of the inductors is disconnected");

+disp(Ir,"the current Ir is (in A)");

+disp(Ib,"the current Ib is (in A)");

+disp(Iy,"the current Iy is (in A)");

+//calculating line current if one of the inductor is short circuited

+Ir=V/Zph;

+Ib=Ir;

+Iph=Ib;

+Iy=2*Iph*cosd(60/2);

+disp("line current if one of the inductor is short circuited");

+disp(Ir,"the current Ir is (in A)");

+disp(Ib,"the current Ib is (in A)");

+disp(Iy,"the current Iy is (in A)");

diff --git a/3673/CH9/EX9.a.6/Example_a_9_6.sce b/3673/CH9/EX9.a.6/Example_a_9_6.sce
new file mode 100644
index 000000000..a28cb176b
--- /dev/null
+++ b/3673/CH9/EX9.a.6/Example_a_9_6.sce
@@ -0,0 +1,25 @@
+//Example_a_9_6 page no:406

+clc;

+Vl=400;

+Vrnmag=400/sqrt(3);

+Vrnang=0;

+Vynmag=400/sqrt(3);

+Vrnang=-120;

+Vbnmag=400/sqrt(3);

+Vrnang=-240;

+R=10;

+omega=314;

+L=1;

+C=100*10^-6;

+Yph=(1/R)+(1/(%i*omega*L))+(%i*omega*C);

+Iph=Vrnmag*Yph;//multiplication of Vrnmag and Yph is rounded off in text book so output line current varies sligthly

+Iphmag=sqrt(real(Iph)^2+imag(Iph)^2);

+Iphang=atand(imag(Iph)/real(Iph));

+P=sqrt(3)*Vl*Iphmag*cosd(Iphang);

+pf=cosd(Iphang);

+disp(Iphmag,"the magnitude of line current is (in A)");

+disp(Iphang,"the angle of line current is (in degree)");

+disp(P,"the power is (in W)");

+disp(pf,"the power factor is");

+//multiplication of Vrnmag and Yph is rounded off in text book so output line current varies sligthly

+//Iphmag and Iphang are rounded off in text book so calculated power varies with the textbook 

diff --git a/3673/CH9/EX9.a.7/Example_a_9_7.sce b/3673/CH9/EX9.a.7/Example_a_9_7.sce
new file mode 100644
index 000000000..a63caefca
--- /dev/null
+++ b/3673/CH9/EX9.a.7/Example_a_9_7.sce
@@ -0,0 +1,17 @@
+//Example_a_9_7 page no:407

+clc;

+Z=3+(%i*4);

+Vrymag=1;//here Vrymag is assumed to be one hence it will be cancelled out in simplification unless the variable cannot be used without initializing

+Vryang=0;

+Vybmag=1;//here Vrymag is assumed to be one hence it will be cancelled out in simplification unless the variable cannot be used without initializing

+Vybang=-120;

+Vmag=Vrymag/Vybmag;

+Vang=Vybang-Vryang;

+Vreal=Vmag*cosd(Vang);

+Vimag=Vmag*sind(Vang);

+V=Vreal+(%i*Vimag);

+Zyb=V*Z;

+R=real(Zyb);

+X=-imag(Zyb);//here negative sign is used hence only the magnitude is required

+disp(R,"the value of R is (in ohm)");

+disp(X,"the value of X(capacitive reactance) is (in ohm)");

diff --git a/3673/CH9/EX9.a.8/Example_a_9_8.sce b/3673/CH9/EX9.a.8/Example_a_9_8.sce
new file mode 100644
index 000000000..67788d014
--- /dev/null
+++ b/3673/CH9/EX9.a.8/Example_a_9_8.sce
@@ -0,0 +1,13 @@
+//Example_a_9_8 page no:408

+clc;

+Iph=10;

+Vl=440;

+pi=30;

+Il=sqrt(3)*Iph;

+Pac=sqrt(3)*Vl*Il*cosd(pi);

+Pac=Pac/1000;//converting to killo Watt

+Prc=sqrt(3)*Vl*Il*sind(pi);

+Prc=Prc/1000;//converting to killo VAR

+disp(Il,"the line current is (in A)");

+disp(Pac,"the total active power is (in KW)");

+disp(Prc,"the total reactive power is (in KVAR)");

diff --git a/3673/CH9/EX9.a.9/Example_a_9_9.sce b/3673/CH9/EX9.a.9/Example_a_9_9.sce
new file mode 100644
index 000000000..82212aaba
--- /dev/null
+++ b/3673/CH9/EX9.a.9/Example_a_9_9.sce
@@ -0,0 +1,43 @@
+//Example_a_9_9 page no:408

+clc;

+V=400;

+Irmag=10;

+Irang=-36.88;

+Iymag=5;

+Iyang=45.57;

+Ibmag=7;

+Ibang=0;

+pf1=0.8;

+pf2=0.7;

+pf3=1;

+Irreal=Irmag*cosd(Irang);

+Irimag=Irmag*sind(Irang);

+Ir=Irreal+(%i*Irimag);

+Iyreal=Iymag*cosd(Iyang);

+Iyimag=Iymag*sind(Iyang);

+Iy=Iyreal+(%i*Iyimag);

+Ibreal=Ibmag*cosd(Ibang);

+Ibimag=Ibmag*sind(Ibang);

+Ib=Ibreal+(%i*Ibimag);

+I1=Ir-Ib;

+I2=Iy-Ir;

+I3=Ib-Iy;

+I1mag=sqrt(real(I1)^2+imag(I1)^2);

+I1ang=atand(imag(I1)/real(I1));

+I2mag=sqrt(real(I2)^2+imag(I2)^2);

+I2ang=atand(imag(I2)/real(I2));

+I2ang=I2ang+180;//converting the angle to positive

+I3mag=sqrt(real(I3)^2+imag(I3)^2);

+I3ang=atand(imag(I3)/real(I3));

+Pry=V*Irmag*pf1;

+Pyb=V*Iymag*pf2;

+Pby=V*Ibmag*pf3;

+Pt=Pry+Pyb+Pby;

+disp(I1mag,"the magnitude of current I1 is (in A)");

+disp(I1ang,"the angle of current I1 is (in degree)");

+disp(I2mag,"the magnitude of current I2 is (in A)");

+disp(I2ang,"the angle of current I2 is (in degree)");//I2 angle is wrongly calculated in text book

+disp(I3mag,"the magnitude of current I3 is (in A)");

+disp(I3ang,"the angle of current I3 is (in degree)");

+disp(Pt,"the total power consumed by the load is (in W)");

+//I2 angle is wrongly calculated in text book, correct calculation is done here