initial commit / add all books

135 files changed, 2298 insertions, 0 deletions

diff --git a/3835/CH1/EX1.1/Ex1_1.sce b/3835/CH1/EX1.1/Ex1_1.sce
new file mode 100644
index 000000000..ca57f82e0
--- /dev/null
+++ b/3835/CH1/EX1.1/Ex1_1.sce
@@ -0,0 +1,8 @@
+clear
+//
+q1=0.2
+q2=0.2
+r=1
+e=8.84*(10**-12)
+E=(q1*q2)/(4*3.14*e*(r**2))
+printf("\n E= %0.1f  N",E)
diff --git a/3835/CH1/EX1.10/Ex1_10.sce b/3835/CH1/EX1.10/Ex1_10.sce
new file mode 100644
index 000000000..f0f67298e
--- /dev/null
+++ b/3835/CH1/EX1.10/Ex1_10.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given and derived
+a=100/0.32 //area required to dissipate 100W power
+d=5
+//length of cyclinder L,length of wire if l,diameter of the wire is d
+L=a/(3.14*d)
+r=100/1**2
+//spacing is d cm
+//distance along the axis of the cylinder is 2d cm
+//no of turns is 10/d
+//length of one turn of the wire is 3.14*5 cm
+//length of the wire is 50*3.14/d
+res=10**-4
+//d=(((2*10**-4))**(0.6))
+d=0.058
+l=(50*3.14)/d
+printf("\n l= %0.1f  cm",l)
diff --git a/3835/CH1/EX1.11/Ex1_11.sce b/3835/CH1/EX1.11/Ex1_11.sce
new file mode 100644
index 000000000..f447decf7
--- /dev/null
+++ b/3835/CH1/EX1.11/Ex1_11.sce
@@ -0,0 +1,12 @@
+clear
+//
+//given
+v=250
+i=5
+i1=3.91
+t0=0.00426 //temperature coefficient
+r15=v/i //at 15 degrees
+rt=v/i1 //at t degrees
+l=(rt*(1+t0*15))/50 //left hand side
+t=(l-1)/t0
+printf("\n t= %0.1f  centigrade",t)
diff --git a/3835/CH1/EX1.12/Ex1_12.sce b/3835/CH1/EX1.12/Ex1_12.sce
new file mode 100644
index 000000000..50ba22d12
--- /dev/null
+++ b/3835/CH1/EX1.12/Ex1_12.sce
@@ -0,0 +1,9 @@
+clear
+//
+//this is a derivation by substitution problem
+//al1=al0/(1+al0*t1)
+//al2=al0/(1+al0*t2)
+//where t1 and t2 are different temperatures al0,al1 and al2 are temperature coefficients
+//substitute al0 in al2
+//on deriving and solving for al2 we get,
+printf("\n al2=al1/(1+al1*(t1-t2))")
diff --git a/3835/CH1/EX1.13/Ex1_13.sce b/3835/CH1/EX1.13/Ex1_13.sce
new file mode 100644
index 000000000..527f55d3c
--- /dev/null
+++ b/3835/CH1/EX1.13/Ex1_13.sce
@@ -0,0 +1,14 @@
+clear
+//
+//values are obtained from the graph
+i=10 //10t A for 0 to 1 second
+d=10 //where di/dt is 10
+L=2
+// at one second
+v=L*d
+printf("\n v= %0.1f  v",v)
+//for 1 to 5 seconds
+d=-5
+//at t=3 seconds voltage across the inductor is
+v=L*d
+printf("\n v= %0.1f  v",v)
diff --git a/3835/CH1/EX1.16/Ex1_16.sce b/3835/CH1/EX1.16/Ex1_16.sce
new file mode 100644
index 000000000..c35015cf2
--- /dev/null
+++ b/3835/CH1/EX1.16/Ex1_16.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given
+dv=20 //dv/dt
+c=25*(10**-6)
+//case a
+i=c*dv
+printf("\n i= %e  A",i)
+//case b
+q=c*dv
+printf("\n q= %e  C",q)
+//case c
+p=dv*i
+printf("\n p= %e  W",p)
+//case d
+v=dv**2
+wc=(c*v)/2
+printf("\n wc= %e  J",wc)
diff --git a/3835/CH1/EX1.18/Ex1_18.sce b/3835/CH1/EX1.18/Ex1_18.sce
new file mode 100644
index 000000000..6b6146ae2
--- /dev/null
+++ b/3835/CH1/EX1.18/Ex1_18.sce
@@ -0,0 +1,15 @@
+clear
+//
+l=1
+b=1.5
+i=50
+u=5
+//case a
+f=b*i*l
+printf("\n f= %0.1f  N",f)
+//case b
+p=f*u
+printf("\n p= %0.1f  W",p)
+//case c
+e=b*l*u
+printf("\n e= %0.1f  V",e)
diff --git a/3835/CH1/EX1.19/Ex1_19.sce b/3835/CH1/EX1.19/Ex1_19.sce
new file mode 100644
index 000000000..4e14e219a
--- /dev/null
+++ b/3835/CH1/EX1.19/Ex1_19.sce
@@ -0,0 +1,14 @@
+clear
+//
+//e=b*l*u*sin(angle)
+b=0.5
+l=40
+u=1.5
+//when angle=90 sin(90)=1=s
+s=1
+e=b*l*u*s
+printf("\n e= %0.1f  V",e)
+//when angle=30 sin(angle)=s=0.5
+s=0.5
+e=b*l*u*s
+printf("\n e= %0.1f  V",e)
diff --git a/3835/CH1/EX1.22/Ex1_22.sce b/3835/CH1/EX1.22/Ex1_22.sce
new file mode 100644
index 000000000..262a7da83
--- /dev/null
+++ b/3835/CH1/EX1.22/Ex1_22.sce
@@ -0,0 +1,11 @@
+clear
+//
+//applying kcl to circuit at node b i3+i4=6-4=2
+vb=8
+vba=2 //voltage drop across nodes b and a
+va=6 //potential of node a w.r.t note c
+i2=3
+//applying kcl to node a
+isa=1
+vs=va+2*isa
+printf("\n vse= %0.1f  V",vs)
diff --git a/3835/CH1/EX1.3/Ex1_3.sce b/3835/CH1/EX1.3/Ex1_3.sce
new file mode 100644
index 000000000..4b511dfd9
--- /dev/null
+++ b/3835/CH1/EX1.3/Ex1_3.sce
@@ -0,0 +1,5 @@
+clear
+//
+charge=1.6*(10**-19)
+iav=1.6*(10**-19)*(10**19) //total charge movement per second
+printf("\n iav= %0.1f  A",iav)
diff --git a/3835/CH1/EX1.4/Ex1_4.sce b/3835/CH1/EX1.4/Ex1_4.sce
new file mode 100644
index 000000000..7e9a00960
--- /dev/null
+++ b/3835/CH1/EX1.4/Ex1_4.sce
@@ -0,0 +1,10 @@
+clear
+//
+p=30
+i=10
+v=p/i
+dt=1
+dq=i*dt
+dw=v*dq
+energy=dw/i
+printf("\n energy of each coulomb of charge= %0.1f  J",energy)
diff --git a/3835/CH1/EX1.5/Ex1_5.sce b/3835/CH1/EX1.5/Ex1_5.sce
new file mode 100644
index 000000000..3c6646422
--- /dev/null
+++ b/3835/CH1/EX1.5/Ex1_5.sce
@@ -0,0 +1,7 @@
+clear
+//
+//given
+p=15000
+n=1500
+t=(60*p)/(1500*2*3.14)
+printf("\n torque= %0.1f  Nm",t)
diff --git a/3835/CH1/EX1.6/Ex1_6.sce b/3835/CH1/EX1.6/Ex1_6.sce
new file mode 100644
index 000000000..a8c4092ec
--- /dev/null
+++ b/3835/CH1/EX1.6/Ex1_6.sce
@@ -0,0 +1,7 @@
+clear
+//
+res=1.72*(10**-8)
+l=200
+a=25*(10**-6)
+R=(res*l)/(a)
+printf("\n R= %0.1f  ohm",R)
diff --git a/3835/CH1/EX1.7/Ex1_7.sce b/3835/CH1/EX1.7/Ex1_7.sce
new file mode 100644
index 000000000..e30ee1412
--- /dev/null
+++ b/3835/CH1/EX1.7/Ex1_7.sce
@@ -0,0 +1,9 @@
+clear
+//
+//given and derived
+meanrad=0.08
+meanlen=3.14*meanrad
+a=0.04*0.04
+res=1.72*(10**-8)
+R=(res*meanlen)/(a)
+printf("\n R= %e  ohm",R)
diff --git a/3835/CH1/EX1.8/Ex1_8.sce b/3835/CH1/EX1.8/Ex1_8.sce
new file mode 100644
index 000000000..2927d3a7b
--- /dev/null
+++ b/3835/CH1/EX1.8/Ex1_8.sce
@@ -0,0 +1,9 @@
+clear
+//
+res=0.02*(10**-6)
+l=4000*80*(10**-2)
+a=0.8*(10**-6)
+R=(res*l)/(a)
+printf("\n R= %0.1f  ohm",R)
+power=(230*230)/(80)
+printf("\n power= %0e  W",power)
diff --git a/3835/CH1/EX1.9/Ex1_9.sce b/3835/CH1/EX1.9/Ex1_9.sce
new file mode 100644
index 000000000..894c0d926
--- /dev/null
+++ b/3835/CH1/EX1.9/Ex1_9.sce
@@ -0,0 +1,17 @@
+clear
+//
+lal=7.5
+lcu=6
+rcu=0.017*(10**-6)
+ral=0.028*(10**-6)
+d=(10**-6)
+a=((3.14*d))/(4)
+Ral=(lal*ral)/(a)
+printf("\n R= %0.1f  ohm",Ral)
+ial=3
+pv=Ral*ial
+Rcu=pv/(2)
+printf("\n Rcu")
+a=(rcu*lcu)/(Rcu)
+dcu=(((a*4)/3.14)**0.5)
+printf("\n dcu= %e  nm",dcu)
diff --git a/3835/CH11/EX11.1/Ex11_1.sce b/3835/CH11/EX11.1/Ex11_1.sce
new file mode 100644
index 000000000..5e5f5b803
--- /dev/null
+++ b/3835/CH11/EX11.1/Ex11_1.sce
@@ -0,0 +1,17 @@
+clear
+//
+//given and derived
+rm=75
+im=300*(10**-6)
+//case a
+i=5
+rsh=(rm*im)/(i-im)
+printf("\n rsh= %e  ohm",rsh)
+//case b
+i=7.5
+rsh=(rm*im)/(i-im)
+printf("\n rsh= %e  ohm",rsh)
+//case c
+i=10
+rsh=(rm*im)/(i-im)
+printf("\n rsh= %e  ohm",rsh)
diff --git a/3835/CH11/EX11.2/Ex11_2.sce b/3835/CH11/EX11.2/Ex11_2.sce
new file mode 100644
index 000000000..9d1544075
--- /dev/null
+++ b/3835/CH11/EX11.2/Ex11_2.sce
@@ -0,0 +1,16 @@
+clear
+//
+im=300*(10**-6)
+rm=75
+//case a
+v=50
+rse=(v/im)-rm
+printf("\n rse= %0.1f  ohm",rse)
+//case b
+v=75
+rse=(v/im)-rm
+printf("\n rse= %0.1f  ohm",rse)
+//case c
+v=100
+rse=(v/im)-rm
+printf("\n rse= %0.1f  ohm",rse)
diff --git a/3835/CH2/EX2.1/Ex2_1.sce b/3835/CH2/EX2.1/Ex2_1.sce
new file mode 100644
index 000000000..8fd2f232d
--- /dev/null
+++ b/3835/CH2/EX2.1/Ex2_1.sce
@@ -0,0 +1,21 @@
+clear
+//
+v=10
+r=4
+//case a
+i=v/(r)
+printf("\n i= %0.1f  A",i)
+//case b
+//6ohm resistor is in series with 4 ohm resistor
+i=v/(6+4)
+v1=i*6
+v2=i*4
+printf("\n voltage across 6 ohm resistor= %0.1f  V",v1)
+printf("\n voltage across 4 ohm resistor= %0.1f  V",v2)
+//case c
+i=10 //constant in both cases
+v4=i*4
+printf("\n voltage when 4 ohm resistor is connected= %0.1f  V",v4)
+v6=i*6
+v=v4+v6
+printf("\n voltage when both resistors are in series= %0.1f  V",v)
diff --git a/3835/CH2/EX2.10/Ex2_10.sce b/3835/CH2/EX2.10/Ex2_10.sce
new file mode 100644
index 000000000..78b9ccf2b
--- /dev/null
+++ b/3835/CH2/EX2.10/Ex2_10.sce
@@ -0,0 +1,19 @@
+clear
+//
+//case a
+I=12/(2+((12*24)/(36))) //values taken from circuit
+I1=I*(24/(36))
+I2=I*(12/(36))
+printf("\n i= %0.1f  A",I)
+printf("\n i1= %0.1f  A",I1)
+printf("\n i2= %0.1f  A",I2)
+//case b
+power=(I**2)*2
+printf("\n power consumed by 2 ohm resistor= %0.1f  W",power)
+power=(I1**2)*12
+printf("\n power consumed by 12 ohm resistor= %0.1f  W",power)
+power=(I2**2)*24
+printf("\n power consumed by 2 ohm resistor= %0.1f  W",power)
+//case c
+v=I*2
+printf("\n voltage drop= %0.1f  V",v)
diff --git a/3835/CH2/EX2.11/Ex2_11.sce b/3835/CH2/EX2.11/Ex2_11.sce
new file mode 100644
index 000000000..cd7e0ae09
--- /dev/null
+++ b/3835/CH2/EX2.11/Ex2_11.sce
@@ -0,0 +1,15 @@
+clear
+//
+//case a
+//values taken and calculated from figure
+r1=6
+r2=12
+r3=18
+rab=3.21 //calculating similar to above using parallel in series resistances
+printf("\n rab=3.12ohm")
+//case b
+r4=30
+r5=15
+r6=30
+ran=6 //similar as above
+printf("\n ran=6 ohm")
diff --git a/3835/CH2/EX2.12/Ex2_12.sce b/3835/CH2/EX2.12/Ex2_12.sce
new file mode 100644
index 000000000..88e7d37ce
--- /dev/null
+++ b/3835/CH2/EX2.12/Ex2_12.sce
@@ -0,0 +1,10 @@
+clear
+//
+//eqns derived from figure
+//6v1-4v2=2-->1
+//-4v1+7v2=-3-->2
+//eqn 1 and 2 are written in matrix form and solved using cramers rule
+printf("\n v1=0.0769 V")
+printf("\n v2=-0.3846V")
+printf("\n current in 0.5ohm resistance is 0.154A,0.25ohm resistance is 1.846,0.66ohm resistor is -1.154A")
+
diff --git a/3835/CH2/EX2.13/Ex2_13.sce b/3835/CH2/EX2.13/Ex2_13.sce
new file mode 100644
index 000000000..15c17e568
--- /dev/null
+++ b/3835/CH2/EX2.13/Ex2_13.sce
@@ -0,0 +1,7 @@
+clear
+//
+//from the figure the eqns are written in matrix form and using cramers rule the value of v1 and v2 can be found
+printf("\n v1=3.6V")
+printf("\n v2=2.2V")
+printf("\n the current in 0.6 ohm resistor is 10.8A,0.2 ohm resistor is 7A,0.16ohm resistor is 13.2 A")
+
diff --git a/3835/CH2/EX2.14/Ex2_14.sce b/3835/CH2/EX2.14/Ex2_14.sce
new file mode 100644
index 000000000..cf5eb71ac
--- /dev/null
+++ b/3835/CH2/EX2.14/Ex2_14.sce
@@ -0,0 +1,6 @@
+clear
+//
+//kcl is applied to the circuit and the eqns obtained are solved using cramer's rule
+printf("\n the voltages of nodes 1 and 3 are 50.29 and 57.71 respectively")
+//i3=v/r
+printf("\n current through 16 ohm resistor is 1.64A")
diff --git a/3835/CH2/EX2.15/Ex2_15.sce b/3835/CH2/EX2.15/Ex2_15.sce
new file mode 100644
index 000000000..c0c983c98
--- /dev/null
+++ b/3835/CH2/EX2.15/Ex2_15.sce
@@ -0,0 +1,8 @@
+clear
+//
+//the eqns obtained are converted to matrix form for solving using cramer's rule values are found
+i1=5.224
+i2=0.7463
+i3=3.28
+v=(i1-i3)*3
+printf("\n voltage across 3 ohm resistor is= %0.1f  V",v)
diff --git a/3835/CH2/EX2.16/Ex2_16.sce b/3835/CH2/EX2.16/Ex2_16.sce
new file mode 100644
index 000000000..4c0914bec
--- /dev/null
+++ b/3835/CH2/EX2.16/Ex2_16.sce
@@ -0,0 +1,4 @@
+clear
+//
+//kvl eqns are obtained from figure which are solved to obtain currents
+printf("\n currents obtained are i1=2.013 and i2=1.273")
diff --git a/3835/CH2/EX2.17/Ex2_17.sce b/3835/CH2/EX2.17/Ex2_17.sce
new file mode 100644
index 000000000..5ed0fff9c
--- /dev/null
+++ b/3835/CH2/EX2.17/Ex2_17.sce
@@ -0,0 +1,12 @@
+clear
+//
+//the currents are obtained by solving the eqns
+i1=5.87
+i2=-0.13
+i3=-1.54
+v=18-1.54*8
+printf("\n voltage at node D= %0.1f  v",v)
+i=5.86/(4)
+printf("\n current in 4 ohm resistor is= %0.1f  A",i)
+power=18*1.54
+printf("\n power supplied by 18V source is= %0.1f  W",power)
diff --git a/3835/CH2/EX2.18/Ex2_18.sce b/3835/CH2/EX2.18/Ex2_18.sce
new file mode 100644
index 000000000..9afc2546b
--- /dev/null
+++ b/3835/CH2/EX2.18/Ex2_18.sce
@@ -0,0 +1,6 @@
+clear
+//
+//node eqns are obtained form the figure
+printf("\n va=8.33V and vb=4.17V")
+i=8.33/(8)
+printf("\n current through 8 ohm resistor is= %0.1f  A",i)
diff --git a/3835/CH2/EX2.19/Ex2_19.sce b/3835/CH2/EX2.19/Ex2_19.sce
new file mode 100644
index 000000000..6322b500a
--- /dev/null
+++ b/3835/CH2/EX2.19/Ex2_19.sce
@@ -0,0 +1,4 @@
+clear
+//
+//eqns obtained are calculated just like above problems and are aolved for i1 and i2
+printf("\n i1=-1.363A and i2=-3.4A")
diff --git a/3835/CH2/EX2.20/Ex2_20.sce b/3835/CH2/EX2.20/Ex2_20.sce
new file mode 100644
index 000000000..dde599768
--- /dev/null
+++ b/3835/CH2/EX2.20/Ex2_20.sce
@@ -0,0 +1,10 @@
+clear
+//
+//eqns are obtained from the figure and are solved for currents
+i1=6.89
+i2=3.89
+i3=-2.12
+i=2*(i2-i1)
+printf("\n current supplied by dependent source is= %0.1f  A",i)
+power=6*i1
+printf("\n power supplied by voltage source is= %0.1f  W",power)
diff --git a/3835/CH2/EX2.21/Ex2_21.sce b/3835/CH2/EX2.21/Ex2_21.sce
new file mode 100644
index 000000000..80045b260
--- /dev/null
+++ b/3835/CH2/EX2.21/Ex2_21.sce
@@ -0,0 +1,12 @@
+clear
+//
+//the following problem is based on usage of superposition theorem
+i8=12/(6+4+8) //current for 8 ohm resistor.the resistances are in series with each other.Hence 6+4+8
+//next when voltage source is short circuited (8+4) total of resistance is obtained.The 4A is distributed in parallel branches as per current divider rule
+i=(4*6)/(6+12)
+printf("\n i8= %0.1f  A",i8)
+printf("\n i8= %0.1f  A",i)
+tot=i8+i
+printf("\n total current= %0.1f  A",tot)
+
+
diff --git a/3835/CH2/EX2.23/Ex2_23.sce b/3835/CH2/EX2.23/Ex2_23.sce
new file mode 100644
index 000000000..946bc7fa2
--- /dev/null
+++ b/3835/CH2/EX2.23/Ex2_23.sce
@@ -0,0 +1,12 @@
+clear
+//
+//thevenin's theorem and superposition theorem used here
+//applying mesh eqns to the 2 circuits and after getting the eqns they are solved using cramer's rule to obtain i1 and i2
+i1=-0.6
+i2=-1.2
+//the value of currents indicates that they have assumed to be flowing in directions opposite to the assumed direction
+vth=12-1.2*3 //voltage eqn
+rth=1.425 //(1+2||12)||3=(1+(2*12)/(2+12))||3=19/7||3=19/7*3/19/7+3=1.425
+i2=vth/(rth+2)
+printf("\n current through 2 ohm resistor is= %0.1f  A",i2)
+printf("\n Note that the same problem is again solved using superposition theorem and hence ignored ")
diff --git a/3835/CH2/EX2.24/Ex2_24.sce b/3835/CH2/EX2.24/Ex2_24.sce
new file mode 100644
index 000000000..511be7370
--- /dev/null
+++ b/3835/CH2/EX2.24/Ex2_24.sce
@@ -0,0 +1,9 @@
+clear
+//
+//using thevenin's theorem
+//applying kcl at node a va is obtained
+va=12
+vth=12-1.2*3 //voltage eqn
+rth=1.33 //2||4
+i5=vth/(rth+5)
+printf("\n current through 5 ohm resistor is= %0.1f  A",i5)
diff --git a/3835/CH2/EX2.25/Ex2_25.sce b/3835/CH2/EX2.25/Ex2_25.sce
new file mode 100644
index 000000000..228307d98
--- /dev/null
+++ b/3835/CH2/EX2.25/Ex2_25.sce
@@ -0,0 +1,9 @@
+clear
+//
+//applying kvl to circuit
+i=0.414
+vth=12-4*0.414 //using vth formula
+//when terminals a and b are short circuited applying kcl to node a gives isc=5*i
+isc=2.07
+rth=vth/isc
+printf("\n rth= %0.1f  A",rth)
diff --git a/3835/CH2/EX2.26/Ex2_26.sce b/3835/CH2/EX2.26/Ex2_26.sce
new file mode 100644
index 000000000..9b077769a
--- /dev/null
+++ b/3835/CH2/EX2.26/Ex2_26.sce
@@ -0,0 +1,9 @@
+clear
+//
+//norton's theorem
+v=10
+//applying kvl to closed circuit 
+isc=12/(2+2) 
+rn=4 //resistance obtained by short circuiting v and opening i
+iab=(4*3)/(4+4) //current through 4 ohm connected across AB
+printf("\n iab= %0.1f  A",iab)
diff --git a/3835/CH2/EX2.27/Ex2_27.sce b/3835/CH2/EX2.27/Ex2_27.sce
new file mode 100644
index 000000000..d72b57acb
--- /dev/null
+++ b/3835/CH2/EX2.27/Ex2_27.sce
@@ -0,0 +1,8 @@
+clear
+//
+//natural frequency needs to be determined
+//req=[(6+6)||4]+[1||2]=3.6666
+req=3.6667
+l=4 //inductance
+s=-req/(l)
+printf("\n natural frequency= %0.1f  secinverse",s)
diff --git a/3835/CH2/EX2.28/Ex2_28.sce b/3835/CH2/EX2.28/Ex2_28.sce
new file mode 100644
index 000000000..d924f7ab6
--- /dev/null
+++ b/3835/CH2/EX2.28/Ex2_28.sce
@@ -0,0 +1,11 @@
+clear
+//
+//req=[10+2+(5||15)]=15.75
+//case a
+c=0.4
+req=15.75
+s=-1/(c*req)
+printf("\n natural frequency= %0.1f  secinverse",s)
+//case b
+tc=req*0.4 //time constant
+printf("\n time constant= %0.1f  sec",tc)
diff --git a/3835/CH2/EX2.3/Ex2_3.sce b/3835/CH2/EX2.3/Ex2_3.sce
new file mode 100644
index 000000000..12c348dc9
--- /dev/null
+++ b/3835/CH2/EX2.3/Ex2_3.sce
@@ -0,0 +1,8 @@
+clear
+//
+v=24
+r=0.75
+ir=v/r
+printf("\n ir= %0.1f  A",ir)
+il=v/(10+r) //since 10 is in series with r
+printf("\n il= %0.1f  A",il)
diff --git a/3835/CH2/EX2.30/Ex2_30.sce b/3835/CH2/EX2.30/Ex2_30.sce
new file mode 100644
index 000000000..68913d182
--- /dev/null
+++ b/3835/CH2/EX2.30/Ex2_30.sce
@@ -0,0 +1,23 @@
+clear
+//
+v=120
+r=40
+i=v/(r)
+//applying kvl to the closed loop
+v=3*520
+printf("\n voltage= %0.1f  v",v)
+//when v=120,R can be found by I*(r+20)=120-->r=20
+r=20
+printf("\n r=20 ohm")
+//when r=20 total r=20+20+20=60
+r=60
+l=10
+tc=l/(r) //time constant
+printf("\n tc= %0.1f  sec",tc)
+//i=I0*e^-(t/tc)=3*e^(-6t)
+energy=(10*9)/(2)
+benergy=0.05*energy
+printf("\n balance energy= %0.1f  J",benergy)
+//(L*i^2)/2=2.25-->hence i=0.6708
+//3*e^-6t=0.6708-->e^-6t=0.2236-->applying log on both sides we get t=0.25
+printf("\n t=0.25 sec")
diff --git a/3835/CH2/EX2.34/Ex2_34.sce b/3835/CH2/EX2.34/Ex2_34.sce
new file mode 100644
index 000000000..abaa4c4e4
--- /dev/null
+++ b/3835/CH2/EX2.34/Ex2_34.sce
@@ -0,0 +1,12 @@
+clear
+//
+v=120
+V=200
+//v=V(1-e^-5/2R)
+//120=200*(1-e^-5/2R)
+//applying log on both sides and solving we get R=2.72 Mohm
+printf("\n R=2.72Mohm")
+R=5 
+tc=10
+//applying in the above eqn and solving lograthmically we get t=9.16
+printf("\n t=9.16 sec")
diff --git a/3835/CH2/EX2.4/Ex2_4.sce b/3835/CH2/EX2.4/Ex2_4.sce
new file mode 100644
index 000000000..90aa8ed6c
--- /dev/null
+++ b/3835/CH2/EX2.4/Ex2_4.sce
@@ -0,0 +1,16 @@
+clear
+//
+vs=12
+rs=0.3
+il=10
+//case a
+p=vs*il
+printf("\n power= %0.1f  W",p)
+//case b
+power=il**2*rs
+printf("\n power dissipated= %0.1f  W",power)
+//case c
+totpow=(vs-il*rs)*il
+printf("\n total power supplied by practical source is= %0.1f  W",totpow)
+i=vs/rs
+printf("\n current source= %0.1f  A",i)
diff --git a/3835/CH2/EX2.5/Ex2_5.sce b/3835/CH2/EX2.5/Ex2_5.sce
new file mode 100644
index 000000000..e43b72bca
--- /dev/null
+++ b/3835/CH2/EX2.5/Ex2_5.sce
@@ -0,0 +1,21 @@
+clear
+//
+//case a
+//v0/vs=r2/(r1+r2)=0.4r2=0.6r1
+r1=10
+r2=(0.6*r1)/(0.4)
+printf("\n r2= %0.1f  ohm",r2)
+//case b
+//when r2 is parallel to r3
+r3=200000
+req=(r2*r3)/(r2+r3)
+printf("\n req= %0.1f  ohm",req)
+//v0/vs=0.5825
+change=(0.6-0.5825)/(0.6)
+printf("\n change")
+r3=20000
+req=(r2*r3)/(r3+r2)
+printf("\n req= %0.1f  ohm",req)
+//v0/vs=0.4615
+change=(0.6-0.4615)/0.6
+printf("\n change")
diff --git a/3835/CH2/EX2.6/Ex2_6.sce b/3835/CH2/EX2.6/Ex2_6.sce
new file mode 100644
index 000000000..6d2a98980
--- /dev/null
+++ b/3835/CH2/EX2.6/Ex2_6.sce
@@ -0,0 +1,13 @@
+clear
+//
+r=2
+i=2
+i3=3 //obtained by applying current divider rule to figure
+i4=1
+req=1/(0.5+0.25+0.166) //1/2,1/4,1/6 values are converted to decimal form
+printf("\n req= %0.1f  ohm",req)
+i2=(4*i4/(6))
+i1=(6*i2)/(req)
+//tracing circuit cabc via 6 ohm resistor and applying ohms law,
+vs=i1*i4+i2*6
+printf("\n vs= %0.1f  V",vs)
diff --git a/3835/CH2/EX2.7/Ex2_7.sce b/3835/CH2/EX2.7/Ex2_7.sce
new file mode 100644
index 000000000..0207ef461
--- /dev/null
+++ b/3835/CH2/EX2.7/Ex2_7.sce
@@ -0,0 +1,6 @@
+clear
+//
+//combining series parallel series
+//[(2+2+2)||(6+5+2)||10]+5
+//[[6*6/6+6]+7]||10]+5=[10+10/10*10]+5=5+5=10
+printf("\n the value of series parallel resistances is 10 ohm")
diff --git a/3835/CH2/EX2.8/Ex2_8.sce b/3835/CH2/EX2.8/Ex2_8.sce
new file mode 100644
index 000000000..471ab3fee
--- /dev/null
+++ b/3835/CH2/EX2.8/Ex2_8.sce
@@ -0,0 +1,16 @@
+clear
+//
+//case a
+//rab=(80+40)||(60+40)
+rab=(120*100)/(120+100)
+printf("\n rab= %0.1f  ohm",rab)
+//rab=(80||60)+(40||40)
+rab=(4800/(140))+(1600/80)
+printf("\n rab= %0.1f  ohm",rab)
+//case b
+//(60+80)||(40+40)
+rcd=(140*80)/(140+80)
+printf("\n rcd= %0.1f  ohm",rcd)
+//(60||40)+(80||40)
+rab=(2400/(100))+(3200/(120))
+printf("\n rab= %0.1f  ohm",rab)
diff --git a/3835/CH2/EX2.9/Ex2_9.sce b/3835/CH2/EX2.9/Ex2_9.sce
new file mode 100644
index 000000000..484161ffe
--- /dev/null
+++ b/3835/CH2/EX2.9/Ex2_9.sce
@@ -0,0 +1,5 @@
+clear
+//
+//simplifying the circuit 
+ceq=1/(0.333+0.666+0.2) //converted to decimal form
+printf("\n ceq= %0.1f  F",ceq)
diff --git a/3835/CH3/EX3.1/Ex3_1.sce b/3835/CH3/EX3.1/Ex3_1.sce
new file mode 100644
index 000000000..a75cd142b
--- /dev/null
+++ b/3835/CH3/EX3.1/Ex3_1.sce
@@ -0,0 +1,14 @@
+clear
+//
+//given
+pi=3.14
+l=%pi*0.2 //l=mean length of the ring=%pi*mean diameter of the ring
+A=400*10**-6 //A=cross sectional area of ring
+u1=1000 //u1=relative permeability of steel
+u2=4*%pi*10**-7 //relative permeability of air
+R=l/(A*u1*u2) //reluctance of steel ring
+printf("\n The reluctance of steel ring is= %0.0f  AT/Wb",R)
+//case b
+flux=500*10**-6
+f=flux*R
+printf("\n The magnetomotive force is= %0.0f  AT",f)
diff --git a/3835/CH3/EX3.10/Ex3_10.sce b/3835/CH3/EX3.10/Ex3_10.sce
new file mode 100644
index 000000000..7af48aec2
--- /dev/null
+++ b/3835/CH3/EX3.10/Ex3_10.sce
@@ -0,0 +1,17 @@
+clear
+//
+//given
+n=2000 //number of turns
+flux=0.05*10**-3 //Wb
+i=10 //A
+lx=(n*flux)/i   //self inductance in X
+printf("\n lx= %0.5f  H",lx)
+//since coils are identical self inductance in Y=self inductance in x
+fluxlinkingX=0.75*0.05*10**-3  //Wb flux linking due to current in coil X
+fluxlinkingY=2000*0.05*0.75*10**-3  //Wb flux linkages in coil Y
+m=fluxlinkingY/5  //mutual inductance
+printf("\n m= %0.5f  H",m)
+//The rate of change in current di/dt=2000A/sec --> di/dt=(10-(-10))/0.01
+rate=2000
+ey=m*rate
+printf("\n The induced emf in coil Y= %0.0f  V",ey)
diff --git a/3835/CH3/EX3.11/Ex3_11.sce b/3835/CH3/EX3.11/Ex3_11.sce
new file mode 100644
index 000000000..6a4737c32
--- /dev/null
+++ b/3835/CH3/EX3.11/Ex3_11.sce
@@ -0,0 +1,14 @@
+clear
+//
+//given
+//when currents are in same direction the total induction is:
+//lt=l1+l2+2m
+//when currents are in opposite direction the total emf is:
+//lt=l1+l2-2m
+//According to this problem
+//l1+l2+2m=1.2
+//l1+l2-2m=0.2
+//Solving the above equations we get l1=0.4H M=0.25H
+//on substituting we get l2=0.3H
+//k=m/squareroot(l1*l2)
+printf("\n k=0.72168")
diff --git a/3835/CH3/EX3.12/Ex3_12.sce b/3835/CH3/EX3.12/Ex3_12.sce
new file mode 100644
index 000000000..917043a7e
--- /dev/null
+++ b/3835/CH3/EX3.12/Ex3_12.sce
@@ -0,0 +1,35 @@
+clear
+//
+//given
+//case a
+B=1 //Wb/m**2
+u1=4*3.14*10**-7
+A=10**-4 //cm**2
+per=800 //permeability
+n=250 //number of turns
+flux=B*A
+printf("\n flux %0.5f  Wb",flux)
+r=781250   //AT/Wb calculated using formula for reluctance
+mmf=flux*r //AT
+i=mmf/n  //exciting current required in A
+printf("\n i %0.5f  A",i)
+l=(n*flux)/i  //self inductance of the coil
+printf("\n l= %0.5f  H",l)
+w=(l*i*i)/2  //energy stored
+printf("\n w= %0.5f  J",w)
+//case b
+airgap=1*10**-3   //air gap is assumed 
+rair=airgap/(u1*A) //reluctance of air gap in AT/Wb
+mmfa=flux*rair     //mmf of air in AT
+printf("\n mmfa")
+//rcore=((2.5*3.14)-0.1)/(32*3.14*10**-6)  //reluctance of core 
+//mmfc=flux*rcore
+mmfc=780 //AT
+F=mmfc+mmfa
+I=F/n  //A
+printf("\n exciting current= %0.2f  A",I)
+n=250 //number of turns
+L=(n*flux)/I   //self inductanc eof coil with air gap 
+printf("\n l= %0.5f  H",L)
+e=(L*I*I)/2  //energy stored in coil
+printf("\n e= %0.5f  J",e)
diff --git a/3835/CH3/EX3.13/Ex3_13.sce b/3835/CH3/EX3.13/Ex3_13.sce
new file mode 100644
index 000000000..14d732c4a
--- /dev/null
+++ b/3835/CH3/EX3.13/Ex3_13.sce
@@ -0,0 +1,14 @@
+clear
+//
+//given
+A=10**-1  //area
+flux=0.1 //Wb
+//case a
+B=flux/A  //flux density Wb/m**2
+u1=4*3.14*10**-7  
+F=(B*B*A)/(2*u1) //force in N
+printf("\n force= %0.5f  N",F)
+//case b
+l=10**-2  //length of the air gap
+w=(B*B*A*l*2)/(2*u1)   //energy stored in two airgaps, 2=air gaps
+printf("\n W= %0.5f  J",w)
diff --git a/3835/CH3/EX3.2/Ex3_2.sce b/3835/CH3/EX3.2/Ex3_2.sce
new file mode 100644
index 000000000..5c1ee3de9
--- /dev/null
+++ b/3835/CH3/EX3.2/Ex3_2.sce
@@ -0,0 +1,35 @@
+clear
+//
+//given
+l=0.5
+A=4*10**-4
+N=250
+I=1.5
+flux=0.25*10**-3
+fluxdensity=flux/A 
+f=N*I //magnetomotive force
+H=(N*I)/l //magnetic field strength
+pi=3.14
+u1=4*%pi*10**-7
+u2=fluxdensity/(u1*H)
+printf("\n The flux density is= %0.3f  Wb/m**2",fluxdensity)
+printf("\n The magnetomotive force is= %0.0f  AT",f)
+printf("\n The magnetic field strength is= %0.0f  AT/m",H)
+printf("\n The relative permeability is= %0.0f  ",u2)
+//case b
+//given
+I=5
+flux=0.6*10**-3
+A=4*10**-4
+N=250
+l=0.5
+fluxdensity=flux/A
+printf("\n The flux density is= %0.1f  Wb/m**2",fluxdensity)
+f=N*I  //magnetomotive force
+printf("\n The magnetomotive force is= %0.0f  AT",f)
+H=(N*I)/l //magnetic field stength
+printf("\n Magnetic field strength= %0.0f  AT/m",H)
+pi=3.14
+u1=4*%pi*10**-7
+u2=fluxdensity/(u1*H)
+printf("\n The relative permeability is= %0.1f  ",u2)
diff --git a/3835/CH3/EX3.3/Ex3_3.sce b/3835/CH3/EX3.3/Ex3_3.sce
new file mode 100644
index 000000000..0c20977ac
--- /dev/null
+++ b/3835/CH3/EX3.3/Ex3_3.sce
@@ -0,0 +1,25 @@
+clear
+//
+//given
+pi=3.14
+N=250
+I=1.5
+ls1=0.627  //mean length of steel string
+la=0.0001 //length of air gap
+A=4.91*10**-4  //cross sectional area of magnetic circuit
+f=N*I //magnetomotive force
+printf("\n Magnetomotive force= %0.0f  AT",f)
+fa=1050  //fa=mmf of air gap=1050AT
+fs=450    //fs=mmf of steel ring=450
+//case b
+u1=4*%pi*10**-7
+ra=la/(u1*A) //reluctance of air gap
+printf("\n The reluctance of air gap is= %0.3f  AT/Wb",ra)
+flux=fa/ra
+printf("\n The flux is=  %0.2f  Wb",flux)
+//case c
+fluxdensity=flux/A
+printf("\n The flux density is= %0.5f  Wb/m**2",fluxdensity)
+//case d
+rs=fs/flux //reluctance of steel string
+printf("\n The reluctance of steel string is= %0.6f  AT/Wb",rs)
diff --git a/3835/CH3/EX3.7/Ex3_7.sce b/3835/CH3/EX3.7/Ex3_7.sce
new file mode 100644
index 000000000..5d2fa0d55
--- /dev/null
+++ b/3835/CH3/EX3.7/Ex3_7.sce
@@ -0,0 +1,35 @@
+clear
+//
+//given
+fluxa=1.4*10**-3
+area=0.002
+B=fluxa/area  //flux density in air gap 
+printf("\n B= %0.3f  Wb/m**2",B)
+//u1=4*3.14*10**-7
+//ha=B/u1 in AT/m    //magnetic field in air gap
+ha=55.7
+la=2  //length of air gap in m
+mmf=ha*la  //mmf of air gap
+printf("\n mmf= %0.3f  AT",mmf)
+//since the flux density of central limb is 0.7 the corresponding field srength is h1=250AT/m
+h1=250
+mmfl=112.45  //mmf for magnetic central limb-->mmf=250*(450-0.2)*10**-3
+totmmf=mmf+mmfl
+printf("\n totmmf= %0.5f  AT",totmmf)
+//mean length of core CGHF=0.75m
+ml=0.75 //as above
+//since the central limb and magnetic core are in parallel they have same mmf that is 223.86AT
+h2=totmmf/ml //magnetic intensity in CGHF
+printf("\n h2= %0.5f  AT",h2)
+flux2=B*area  
+printf("\n flux2= %0.5f  Wb",flux2)
+totflux=fluxa+flux2  //Wb
+Bfabc=totflux/area   //flux density in magnetic core fabc in Wb/m**2
+H=3000 //AT/m
+totmmffabc=H*ml  //total mmf in fabc in AT
+printf("\n total mmf in fabc= %0.5f  Wb/m**2",totmmffabc)
+totmmfm=totmmffabc+totmmf  //total mmf in magnetic core in AT
+printf("\n totmmfm= %0.5f  AT",totmmfm)
+N=500
+I=totmmfm/N   //The required current to set up flux in air gap
+printf("\n The total current required to set up flux in air gap is= %0.5f  A",I)
diff --git a/3835/CH3/EX3.8/Ex3_8.sce b/3835/CH3/EX3.8/Ex3_8.sce
new file mode 100644
index 000000000..684507d7c
--- /dev/null
+++ b/3835/CH3/EX3.8/Ex3_8.sce
@@ -0,0 +1,34 @@
+clear
+//
+//given
+r1=3.98*10**6   //reluctance of air gap in AT/Wb and the value is same for r2
+r3=5.97*10**6   //reluctance of air gap in AT/Wb
+//assume that current of 1A flows through 150 turns coil,for assumed directions of fluxes application of mesh current leads to matrix equations that can be simplified to:
+//[flux1 flux2]=[2.36 1.41]*10**-5 Wb
+//The self inductance and mutual inductance are obtained as follows:
+n1=150 //number of turns
+i1=1   //A
+flux1=2.36*10**-5  //Wb
+l1=(n1*flux1)/i1  //self inductance
+printf("\n l1= %0.3f  mH",l1)
+n2=200  //number of turns
+flux2=1.41*10**-5
+m12=(n2*flux2)/i1  //mutual inductance
+printf("\n m12= %0.3f  mH",m12)
+//assume that 1A of current flows through 200 turns coil
+//The self inductance of the coil is determined as above using the matrix and the result is as follows
+//[flux1 flux2]=[1.89 3.14]*10**-5 Wb
+//Hence self and mutual inductance are computed as follows
+n2=200 //number of turns
+flux2=3.14*10**-5 //Wb
+i2=1 //A
+l2=(n2*flux2)/i2  //self inductance
+printf("\n l2= %0.3f  mH",l2)
+flux1=1.89*10**-5
+m21=(n1*flux1)/i2  //mutual inductance
+printf("\n m21= %0.3f  mH",m21)
+//case b
+//When the air gap l3 is closed the reluctance of the limb is zero since the permeability of the magnetic material is infinity.Thus,the limb behaves like short circuit and the entire flux passes through it.Thus,the flux linking 200 turns coil is zero and mutual inductance is zero
+//case 3
+W=((3.5)/2)+((6.3)/2)+2.8 //work equation in joules
+printf("\n Work done= %0.5f  J",W)
diff --git a/3835/CH3/EX3.9/Ex3_9.sce b/3835/CH3/EX3.9/Ex3_9.sce
new file mode 100644
index 000000000..012cde006
--- /dev/null
+++ b/3835/CH3/EX3.9/Ex3_9.sce
@@ -0,0 +1,29 @@
+clear
+//
+//given
+B=0.8 //Wb/m**2
+A=25*10**-4 //m**2
+flux=20*10**-4 //Wb
+l=3.14*40*10**-2 //m
+f=2000*3.14 //AT
+n=800 //number of turns
+//case a
+i=f/n  //A exciting current
+printf("\n i= %0.3f  A",i)
+l=(n*flux)/i   //self inductance in H
+printf("\n l= %0.5f  H",l)
+//case b
+fluxa=20*10**-4  //Wb
+gap=1*10**-2
+u1=4*3.14*10**-7
+rair=gap/(u1*A) //reluctance of air in AT/Wb
+printf("\n rair= %0.5f  AT/Wb",rair)
+fair=rair*flux  //mmf for air gap in AT
+printf("\n fair= %0.5f  AT",fair)
+fcore=6233.18 //AT--> 5000*((0.4*3.14)-0.01)=6233.18
+totmmf=fcore+fair
+printf("\n total mmf= %0.5f  AT",totmmf)
+I=totmmf/n //A exciting current
+//self inductance
+L=(n*flux)/I
+printf("\n L= %0.5f  H",L)
diff --git a/3835/CH4/EX4.1/Ex4_1.sce b/3835/CH4/EX4.1/Ex4_1.sce
new file mode 100644
index 000000000..88ea9a08f
--- /dev/null
+++ b/3835/CH4/EX4.1/Ex4_1.sce
@@ -0,0 +1,22 @@
+clear
+//
+//given
+b=0.2
+a=0.04
+n=1000/(60) //rev/sec
+t=500
+//case a
+//since coil is at right angles ang=0
+printf("\n e(t)=0 V")
+//case b
+//when coil is 30deg to the field ang=60
+//p=sin(60) 
+p=0.8660254
+e=2*3.14*a*n*b*t*p
+printf("\n e(t)= %0.1f  V",e)
+//case c
+//when ang=90 that is coil is in the plane of the field
+//p=sin(90)
+p=1
+e=2*3.14*b*a*n*p*t
+printf("\n e(t)= %0.1f  V",e)
diff --git a/3835/CH4/EX4.11/Ex4_11.sce b/3835/CH4/EX4.11/Ex4_11.sce
new file mode 100644
index 000000000..4bd67c4c5
--- /dev/null
+++ b/3835/CH4/EX4.11/Ex4_11.sce
@@ -0,0 +1,9 @@
+clear
+//
+//i1=20*sin(314t+60),i2=-10*sin(314t),i3=15*sin(314t-45)-->angles are in degrees
+//I1=(7.7072+j12.25),I2=(-7.072),I3=7.5-j7.5
+//adding phasor currents I1,I2 and I3
+//I=7.702+j12.25-7.702+7.5-j7.5=7.5+j4.75
+printf("\n I=7.5+j4.75. Its value in polar form is obtained as 8.8776 at angle 32.34")
+//i=2**0.5*8.8776*sin(314t+32.34)-->instantaneous value of resultant i
+printf("\n instantaneous value of resultant i is 12.5548*sin(314t+32.34)")
diff --git a/3835/CH4/EX4.12/Ex4_12.sce b/3835/CH4/EX4.12/Ex4_12.sce
new file mode 100644
index 000000000..846aca9b7
--- /dev/null
+++ b/3835/CH4/EX4.12/Ex4_12.sce
@@ -0,0 +1,16 @@
+clear
+//
+v=230
+f=50
+L=50*10**-3
+r=10
+//case a
+xl=2*3.14*f*L
+z=complex(r,xl)
+//the value of z in polar form is 18.62 ohm
+z=18.62
+i=v/(z)
+printf("\n i= %0.1f  A",i)
+//case b
+//phy=taninverse(xl/r)=57.52 lag
+printf("\n phase angle of current=57.52 lag")
diff --git a/3835/CH4/EX4.13/Ex4_13.sce b/3835/CH4/EX4.13/Ex4_13.sce
new file mode 100644
index 000000000..46738a49c
--- /dev/null
+++ b/3835/CH4/EX4.13/Ex4_13.sce
@@ -0,0 +1,11 @@
+clear
+//
+vr=150
+r=50
+l=250*10**-3
+f=50
+i=vr/r
+xl=2*3.14*f*l
+vl=i*xl
+v=(((vr**2)+(vl**2))**0.5)
+printf("\n v= %0.1f  V",v)
diff --git a/3835/CH4/EX4.14/Ex4_14.sce b/3835/CH4/EX4.14/Ex4_14.sce
new file mode 100644
index 000000000..80a913cfe
--- /dev/null
+++ b/3835/CH4/EX4.14/Ex4_14.sce
@@ -0,0 +1,22 @@
+clear
+//
+v=200
+f=50
+r=20
+vr=100
+vc=144
+vl=150
+//case a
+//from eqn ((vr**2+vl*cos1(angle))**2)+((vl*sin(angle))**2)=v**2
+//on substituting values in the above eqn the value of angle can be found by isolating cos1
+//angle=75.52
+cos1=0.25
+pf=(vr+vl*cos1)/(v)
+printf("\n pf")
+//case b
+i=vr/r
+power=i**2*r
+printf("\n power consumed= %0.1f  w",power)
+//case c
+power=vl*i*cos1
+printf("\n power consumed in choke oil= %0.1f  W",power)
diff --git a/3835/CH4/EX4.15/Ex4_15.sce b/3835/CH4/EX4.15/Ex4_15.sce
new file mode 100644
index 000000000..a3d7ba78d
--- /dev/null
+++ b/3835/CH4/EX4.15/Ex4_15.sce
@@ -0,0 +1,25 @@
+clear
+//
+r=10
+c=10**-4
+v=230
+f=50
+omega=314
+//case a
+xc=1/(omega*c)
+printf("\n xc= %0.1f  ohm",xc)
+//case b
+zc=33.38 //zc=10-j31.85 into polar form is 33.38
+i=v/zc
+printf("\n i= %0.1f  A",i)
+//case c
+pf=r/zc
+printf("\n pf")
+//case d
+//phase angle=cosinverse(0.3)=72.6
+printf("\n phase angle=72.6")
+//case e
+v=r*i
+printf("\n v= %0.1f  v",v)
+v=xc*i
+printf("\n v= %0.1f  v",v)
diff --git a/3835/CH4/EX4.16/Ex4_16.sce b/3835/CH4/EX4.16/Ex4_16.sce
new file mode 100644
index 000000000..de94ea6a1
--- /dev/null
+++ b/3835/CH4/EX4.16/Ex4_16.sce
@@ -0,0 +1,19 @@
+clear
+//
+v=230
+f=50
+//voltage vr across r is in phase with the current i while voltage vc across c lage i by 90
+//from phasor diagram v**2=vr**2+vc**2
+vr=100
+vc=((v**2)-(vr**2))**0.5
+printf("\n vc= %0.1f  v",vc)
+p=500 //power
+i=p/vr
+c=i/(2*3.14*f*vc)
+printf("\n c= %e  F",c)
+//case b
+v=(2**0.5)*vc
+printf("\n maximum voltage across c= %0.1f  V",v)
+//case c
+//phase angle=cosinverse(vr/v)=cosinverse(0.4348)=64.2
+printf("\n phase angle=64.2")
diff --git a/3835/CH4/EX4.17/Ex4_17.sce b/3835/CH4/EX4.17/Ex4_17.sce
new file mode 100644
index 000000000..52ea84c1a
--- /dev/null
+++ b/3835/CH4/EX4.17/Ex4_17.sce
@@ -0,0 +1,30 @@
+clear
+//
+r=8
+l=0.15
+f=50
+v=230
+c=125*10**-6
+//case a inductive reactance
+xl=2*3.14*f*l
+printf("\n xl= %0.1f  ohm",xl)
+//case b capacitance reactance
+xc=1/(2*3.14*f*c)
+printf("\n xc= %0.0f ohm",xc)
+//case c complex impedance
+//z=r+j(xl-xc)-->on substituting valuees we get z=8+j21.62
+//z=((8**2)+(21.62**2))**0.5
+printf("\n complex impedance=8+j21.62 at an impedance angle of 69.7")
+//impedance angle=taninverse(xl-xr)/r
+//case d
+v=230
+z=23.05
+i=v/z
+printf("\n current= %0.1f  A",i)
+//case e
+//(r+jxl)*i=446.8 at 10.66 degrees
+printf("\n voltage across coil=446.8 at 10.66 degrees")
+//-j*xc*i=25.48*9.98
+printf("\n voltage across capacitor=-254.29 at -159.7 degrees")
+//case e
+printf("\n phase difference between supply and current i is 69.7 lag')
diff --git a/3835/CH4/EX4.18/Ex4_18.sce b/3835/CH4/EX4.18/Ex4_18.sce
new file mode 100644
index 000000000..125f4ace1
--- /dev/null
+++ b/3835/CH4/EX4.18/Ex4_18.sce
@@ -0,0 +1,28 @@
+clear
+//
+c=50*10**-6
+i=2.355
+//case a
+vl=120
+vr=70
+vac=150
+//the phasor sum of vr and vl is OCthe applied voltage v is the phasor sum of vc and OC and is represented by OV
+//the theta be the impedance angle of RL combination
+//from right angled triangle OCD,theta can be determined as follows:
+//(vr+vl*costheta)**2+(vl*costheta)**2=vac**2
+//substitute the values then value of costheta can be found
+zl=vl/i //impedance of the coil
+p=0.981 //value of sin(79)
+xl=zl*p
+q=0.19 //value of cos(79)
+r=zl*q
+dc=i*xl
+bd=i*r
+//from right angled triangle ODB in fig.
+v=98.3
+xc=vac/i
+printf("\n capacitive reactance= %0.1f  ohm",xc)
+f=1/(xc*2*3.14*c)
+printf("\n f= %0.1f  cycles/sec",f)
+ploss=i**2*r
+printf("\n power loss in iron cored choke is= %0.1f  w",ploss)
diff --git a/3835/CH4/EX4.19/Ex4_19.sce b/3835/CH4/EX4.19/Ex4_19.sce
new file mode 100644
index 000000000..736c28004
--- /dev/null
+++ b/3835/CH4/EX4.19/Ex4_19.sce
@@ -0,0 +1,11 @@
+clear
+//
+r=20
+l=200*10**-3
+v=230
+f=50
+xl=314*l //314 is omega
+ir=v/(r)
+il=v/(xl)
+i=((ir**2)+(il**2))**0.5
+printf("\n i= %0.1f  A",i)
diff --git a/3835/CH4/EX4.2/Ex4_2.sce b/3835/CH4/EX4.2/Ex4_2.sce
new file mode 100644
index 000000000..9e41ffa41
--- /dev/null
+++ b/3835/CH4/EX4.2/Ex4_2.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given
+vm=155
+omega=377
+//case a
+t=(2*3.14)/(omega)
+printf("\n t= %e  sec",t)
+//case b
+f=1/(t)
+printf("\n f= %e  Hz",f)
+//case c
+v=109.60 //rms value
+//at t=0 -77.5=155*sin(ang)
+//therefore, ang=-0.5236 rad
+ang=-0.5236
+t=ang/omega
+printf("\n t= %e  sec",t)
diff --git a/3835/CH4/EX4.20/Ex4_20.sce b/3835/CH4/EX4.20/Ex4_20.sce
new file mode 100644
index 000000000..206174e7b
--- /dev/null
+++ b/3835/CH4/EX4.20/Ex4_20.sce
@@ -0,0 +1,12 @@
+clear
+//
+r=100
+c=50*10**-6
+f=50
+v=230
+//case a
+xc=-1/(314*c) //314 is omega
+ir=v/r //with angle 0
+ic=230/(xc) //with angle of 90 deg
+i=((ir**2)+(ic**2))**0.5
+printf("\n current with a lead of 57.5 is obtained as= %0.1f  A",i)
diff --git a/3835/CH4/EX4.21/Ex4_21.sce b/3835/CH4/EX4.21/Ex4_21.sce
new file mode 100644
index 000000000..c4eddcd28
--- /dev/null
+++ b/3835/CH4/EX4.21/Ex4_21.sce
@@ -0,0 +1,16 @@
+clear
+//
+r=100
+l=0.1
+c=150*10**-6
+v=230
+f=50
+//case a
+xl=314*l //at 90 deg
+xc=1/(314*c) //at lag -90 deg
+ir=v/r //at 0 deg
+il=v/xl
+ic=v/xc
+//i=ir+ic+il-->2.3+j3.51
+i=((2.3**2)+(3.51**2))**0.5
+printf("\n current at 56.76 lead= %0.1f  A",i)
diff --git a/3835/CH4/EX4.22/Ex4_22.sce b/3835/CH4/EX4.22/Ex4_22.sce
new file mode 100644
index 000000000..3de2e7f49
--- /dev/null
+++ b/3835/CH4/EX4.22/Ex4_22.sce
@@ -0,0 +1,10 @@
+clear
+//
+z1=18.03 //z1=10+j15 converted to polar form also it is at angle 56.31
+z2=32.02
+z3=10.77
+//ybc=1/zbc=(1/z2+1/z3)=1/32.02+1/10.77
+//on performing the add operation we get the value of zbc as 8.159-j9.553 that is in rectangular form
+printf("\n The value of zbc is 8.159-j9.553")
+//thus total impedance between terminals A and C is given by zac=z1+zbc
+printf("\n zac=18.159+j5.447(in rectangular form)")
diff --git a/3835/CH4/EX4.23/Ex4_23.sce b/3835/CH4/EX4.23/Ex4_23.sce
new file mode 100644
index 000000000..498678065
--- /dev/null
+++ b/3835/CH4/EX4.23/Ex4_23.sce
@@ -0,0 +1,34 @@
+clear
+//
+r1=25
+l1=0.159
+r2=60
+c=125*10**-6
+v=230
+f=50
+//case a
+xl=2*3.14*f*l1
+z1=((r1**2)+(xl**2))**0.5
+i1=v/z1
+//phy1=cosinverse(r1/z1)=63.43 lag
+xc=1/(2*3.14**c)
+z2=((r2**2)+(xc**2))**0.5
+i2=v/z2
+//i2 has 23 deg lead calculated similar to i1
+//p=cosphy1
+//q=cosphy2
+p=0.44
+q=0.92
+I1=i1*p+i2*q
+a=-0.89
+b=0.39
+I2=i1*a+i2*b
+I=((I1**2)+(I2**2))**0.5
+printf("\n I= %0.1f  A",I)
+//case b
+z=v/I
+printf("\n z= %0.1f  ohm",z)
+R=(z*I1)/I //note the value of I in text is printed wrongly so the result may vary
+printf("\n R= %0.1f  ohm",R)
+x=(z*I2)/I //same note applicable here as well
+printf("\n x= %0.1f  ohm",x)
diff --git a/3835/CH4/EX4.24/Ex4_24.sce b/3835/CH4/EX4.24/Ex4_24.sce
new file mode 100644
index 000000000..75365dcf3
--- /dev/null
+++ b/3835/CH4/EX4.24/Ex4_24.sce
@@ -0,0 +1,21 @@
+clear
+//
+//given
+//z1=15+j20
+//z2=8-j10
+I=20
+z1=25 //in polar form at angle 53.13
+z2=12.81 //at angle -51.34
+//v=I1z1=I2z2
+//I2=1.95I1
+//from diagram I**2=(I1cosang1+I2cosang2)**2+(I2sinang2-I1sinang1)**2
+//on substituting values in the above eqn and simplifying
+I1=6.78
+printf("\n I1=6.78A")
+I2=13.22
+//substitute this in I2=1.95I1
+printf("\n I2=13.22A")
+pow1=I1**2*15
+pow2=I2**2*8
+printf("\n power loss in z1= %0.1f  W",pow1)
+printf("\n power loss in z2= %0.1f  W",pow2)
diff --git a/3835/CH4/EX4.26/Ex4_26.sce b/3835/CH4/EX4.26/Ex4_26.sce
new file mode 100644
index 000000000..c0f3b0061
--- /dev/null
+++ b/3835/CH4/EX4.26/Ex4_26.sce
@@ -0,0 +1,9 @@
+clear
+//
+z1=complex(6,-10)
+z2=complex(10,15)
+z3=complex(18,12)
+//z1+z2 is parallel to z3
+zab=z1+(z2*z3)/(z2+z3)
+printf("\n zab")
+printf("\n the phase angle is -12.11")
diff --git a/3835/CH4/EX4.29/Ex4_29.sce b/3835/CH4/EX4.29/Ex4_29.sce
new file mode 100644
index 000000000..9ad1928ef
--- /dev/null
+++ b/3835/CH4/EX4.29/Ex4_29.sce
@@ -0,0 +1,17 @@
+clear
+//
+//case a
+l=0.25
+f=50
+v=230
+r=2
+c=1/(((2*3.14*f)**2)*l)
+printf("\n c= %e  ",c)
+//case b
+i=v/r
+printf("\n i= %0.1f  A",i)
+//case c
+vl=2*3.14*f*l*i
+vc=i/(c*2*3.14*f)
+q=(2*3.14*f*l)/(r)
+printf("\n q")
diff --git a/3835/CH4/EX4.3/Ex4_3.sce b/3835/CH4/EX4.3/Ex4_3.sce
new file mode 100644
index 000000000..a44645e7d
--- /dev/null
+++ b/3835/CH4/EX4.3/Ex4_3.sce
@@ -0,0 +1,19 @@
+clear
+//
+//given
+//i=14.14*sin(314t)-->i=im*sin(omega*t)
+//case a
+im=14.14
+i=14.14/1.414 //1.414 is  the value of root 2
+printf("\n i= %0.1f  A",i)
+//case b
+//omega=314=2*3.14*f
+f=314/(2*3.14)
+printf("\n f= %0.1f  A",f)
+//case c
+t=0.002
+//i=im*sin(omega*t)
+p=0.01096 //value of sin(omega*t)
+i=im*p
+printf("\n i= %0.1f  A",i)
+printf("\n NOTE:Answer calculated wrongly in textbook for i obtained here")
diff --git a/3835/CH4/EX4.30/Ex4_30.sce b/3835/CH4/EX4.30/Ex4_30.sce
new file mode 100644
index 000000000..f572f91b9
--- /dev/null
+++ b/3835/CH4/EX4.30/Ex4_30.sce
@@ -0,0 +1,19 @@
+clear
+//
+l=10
+r=100
+i=1
+f=100
+i1=0.5
+c=1/(4*(3.14**2)*(r**2)*l)
+v=i*r
+z=v/i1
+//z=100+jX
+x=((200**2)-(100**2))**0.5
+omega=641.1 //angular frequency in rad/sec
+f0=omega/(2*3.14)
+f1=f0-(r/(4*3.14*l))
+f2=f0+(r/(4*3.14*l))
+printf("\n f0= %0.1f  Hz",f0)
+printf("\n f1= %0.1f  Hz",f1)
+printf("\n f2= %0.1f  Hz",f2)
diff --git a/3835/CH4/EX4.31/Ex4_31.sce b/3835/CH4/EX4.31/Ex4_31.sce
new file mode 100644
index 000000000..1c125702c
--- /dev/null
+++ b/3835/CH4/EX4.31/Ex4_31.sce
@@ -0,0 +1,8 @@
+clear
+//
+v=3*10**8
+lamb=3000
+c=0.0005*10**-6
+f=v/lamb
+l=1/(4*3.14*3.14*f**2*c)
+printf("\n l= %e  H",l)
diff --git a/3835/CH4/EX4.32/Ex4_32.sce b/3835/CH4/EX4.32/Ex4_32.sce
new file mode 100644
index 000000000..f53d9b5c1
--- /dev/null
+++ b/3835/CH4/EX4.32/Ex4_32.sce
@@ -0,0 +1,17 @@
+clear
+//
+r=1500
+l=0.2
+v=1.5
+f=15000
+//case a
+//p=1/0.2c
+p=(4*3.14*3.14*f**2)+(r**2)/(l**2)
+c=1/(0.2*p)
+printf("\n c= %e  F",c)
+//case b
+z=l/(c*r)
+printf("\n z= %0.1f  ohm",z)
+//case c
+i=v/(z)
+printf("\n i= %0.1f  A",i)
diff --git a/3835/CH4/EX4.33/Ex4_33.sce b/3835/CH4/EX4.33/Ex4_33.sce
new file mode 100644
index 000000000..a0d8da52e
--- /dev/null
+++ b/3835/CH4/EX4.33/Ex4_33.sce
@@ -0,0 +1,12 @@
+clear
+//
+//the eqns are formed using the given diagram
+//the derivations from the eqns are obtained as below using matrices for their construction
+//the below eqns are in polar form
+delta=0.3165
+delta1=5.95
+delta2=6.82
+v1=delta1/delta
+printf("\n v1 at -47.63 is= %0.1f  V",v1)
+v2=delta2/delta
+printf("\n v2 at -42.30 is= %0.1f  V",v2)
diff --git a/3835/CH4/EX4.34/Ex4_34.sce b/3835/CH4/EX4.34/Ex4_34.sce
new file mode 100644
index 000000000..ce97a3c5e
--- /dev/null
+++ b/3835/CH4/EX4.34/Ex4_34.sce
@@ -0,0 +1,14 @@
+clear
+//
+//in polar form
+z1=10
+z2=12.806
+z3=13.416
+//the mesh currents are written in matrix form
+delta=329.31 //in polar form
+delta1=360
+delta2=793.22
+i1=delta1/delta
+i2=delta2/delta
+i=i1-i2 //answer obtained in text is wrongly printed
+printf("\n i at -84.21 is= %0.1f  V",i)
diff --git a/3835/CH4/EX4.35/Ex4_35.sce b/3835/CH4/EX4.35/Ex4_35.sce
new file mode 100644
index 000000000..ca622f478
--- /dev/null
+++ b/3835/CH4/EX4.35/Ex4_35.sce
@@ -0,0 +1,21 @@
+clear
+//
+//superposition theorem
+r=4
+//z=4+(8+6j)*(0-j10)/8+j6+0-j10
+//z=14-j5
+z=14.87
+l=40
+//I1a=z/l=2.69 in polar form
+I1a=complex(2.533,0.904)
+I2a=complex(-0.324,-2.67)
+//from fig c
+z=complex(2.93,-9.47)
+I1b=complex(-0.895,3.935)
+I2b=complex(1.056,-2.474)
+I1=I1a+I1b
+printf("\n I1")
+I2=I2a+I2b
+printf("\n I2")
+I=I1+I2
+printf("\n I")
diff --git a/3835/CH4/EX4.36/Ex4_36.sce b/3835/CH4/EX4.36/Ex4_36.sce
new file mode 100644
index 000000000..456a2dfd0
--- /dev/null
+++ b/3835/CH4/EX4.36/Ex4_36.sce
@@ -0,0 +1,12 @@
+clear
+//
+//thevenin's theorem
+//all the values are derived from the figures
+z1=complex(8,-6)
+z2=complex(0,5)
+zth=(z1*z2)/(z1+z2)
+printf("\n zth")
+vth=complex(-17.71,141.54)
+zload=complex(4,3)
+I=vth/(zth+zload)
+printf("\n I")
diff --git a/3835/CH4/EX4.37/Ex4_37.sce b/3835/CH4/EX4.37/Ex4_37.sce
new file mode 100644
index 000000000..7e6be9bac
--- /dev/null
+++ b/3835/CH4/EX4.37/Ex4_37.sce
@@ -0,0 +1,13 @@
+clear
+//
+//norton's theorem
+//values derived and calculated from figure
+v=complex(230,0)
+xl=complex(8,-6)
+isc=v/xl
+IN=isc
+rl=complex(0,5)
+zn=(rl*xl)/(rl+xl)
+zload=complex(4,3)
+I=(IN*zn)/(zn+zload)
+printf("\n I")
diff --git a/3835/CH4/EX4.38/Ex4_38.sce b/3835/CH4/EX4.38/Ex4_38.sce
new file mode 100644
index 000000000..4f6f2821b
--- /dev/null
+++ b/3835/CH4/EX4.38/Ex4_38.sce
@@ -0,0 +1,14 @@
+clear
+//
+//all values derived from figure
+//zth=complex(0.923,2.615)
+//vth=complex(-4.615,-6.923) //derived using formula
+//zl=complex(0.923,-2.615)
+//z=zl+zth
+vth=8.32 //polar form
+z=1.846
+I=vth/z
+printf("\n I= %0.1f  A",I)
+rl=0.923
+pl=(I**2)*rl
+printf("\n pl= %0.1f  w",pl)
diff --git a/3835/CH4/EX4.4/Ex4_4.sce b/3835/CH4/EX4.4/Ex4_4.sce
new file mode 100644
index 000000000..d008291cf
--- /dev/null
+++ b/3835/CH4/EX4.4/Ex4_4.sce
@@ -0,0 +1,10 @@
+clear
+//
+i=20
+im=i/(1.414) //that is i*root 2
+//the heat produced by i is the sum of heat produced by dc and ac current
+p=i**2
+q=im**2
+r=p+q
+I=(r**0.5)
+printf("\n I= %0.1f  A",I)
diff --git a/3835/CH4/EX4.5/Ex4_5.sce b/3835/CH4/EX4.5/Ex4_5.sce
new file mode 100644
index 000000000..90ef398bf
--- /dev/null
+++ b/3835/CH4/EX4.5/Ex4_5.sce
@@ -0,0 +1,20 @@
+clear
+//
+f=50
+irms=10
+im=irms/(0.707)
+//omega*t=2*3.14*f*t here the value for t can be substituted and value for i can be found from i=im*sin(omega*t)
+t=0.0025
+p=0.0137 //value of sin(314*0.0025)
+i=(10*p)/(0.707)
+printf("\n i= %0.1f  A",i)
+//maximum value is when 314*t=%pi/2 (in radians)-->t=0.005
+//hence at t=0.005+0.0125=0.0175 the value of i nedds to be found
+p=0.0957
+i=(10*p)/(0.707)
+printf("\n i= %0.1f  A",i)
+printf("\n NOTE:The answer given in text is printed wrongly")
+i=7.07
+//7.07=(10*sin314t)/0.707-->t=0.00833 sec
+t=0.00833-0.005 //the time at which the instaneous value is 7.07A after positive maximum value is at this time
+printf("\n t= %e  A",t)
diff --git a/3835/CH4/EX4.6/Ex4_6.sce b/3835/CH4/EX4.6/Ex4_6.sce
new file mode 100644
index 000000000..6ffd7a5e5
--- /dev/null
+++ b/3835/CH4/EX4.6/Ex4_6.sce
@@ -0,0 +1,23 @@
+clear
+//
+//from graph 
+a=0
+b=5**2
+c=10**2
+c=20**2
+d=40**2
+e=50**2
+f=40**2
+g=20**2
+h=10**2
+i=5**2
+v=(0.1*(a+b+c+d+e+f+g+h+i))**0.5 //%pi and omega values get cancelled
+printf("\n v= %0.1f  V",v)
+vavg=0.1*(0+5+10+20+40+50+40+20+10+5)
+printf("\n vavg= %0.1f  v",vavg)
+ff=v/(vavg)
+printf("\n %0.1f",ff)
+pf=50/(v) //50 is the maximum value
+printf("\n %0.1f",pf)
+v=0.707*50 
+printf("\n rms value for a sin wave with the same peak value is= %0.1f  V",v)
diff --git a/3835/CH4/EX4.8/Ex4_8.sce b/3835/CH4/EX4.8/Ex4_8.sce
new file mode 100644
index 000000000..f6a489f98
--- /dev/null
+++ b/3835/CH4/EX4.8/Ex4_8.sce
@@ -0,0 +1,13 @@
+clear
+//
+//from phasor diagram vac=vab+vbc
+hcab=60
+vcab=60
+hcbc=45
+vcbc=77.94 //vbc=60*sin(60)
+p=(vcab+hcbc)**2
+q=vcbc**2
+vac=((p+q)**0.5)
+printf("\n vac= %0.1f  v",vac)
+//the angle is given by ang=taninverse(vcbc/(vcab+hcbc))=36.59
+printf("\n phase position with respect to vbc=60-36.59=23.41")
diff --git a/3835/CH5/EX5.1/Ex5_1.sce b/3835/CH5/EX5.1/Ex5_1.sce
new file mode 100644
index 000000000..8c1df16f3
--- /dev/null
+++ b/3835/CH5/EX5.1/Ex5_1.sce
@@ -0,0 +1,24 @@
+clear
+//
+//given
+vl=400 //line voltage
+va=vl/sqrt(3)
+vb=230.94  //angle(-120)
+vc=230.94  //angle(-240)
+//case a
+//the line currents are given by
+ia=12000/230.94  //with angle 0
+ib=10000/230.94  //with angle 120
+ic=8000/230.94   //with angle 240
+printf("\n ia= %0.3f  A",ia)
+printf("\n ib= %0.5f  A",ib)
+printf("\n ic= %0.5f  A",ic)
+//case b
+//IN=ia+ib+ic
+//ia,ib and ic are phase currents hence contain with angles they are in the form sin(angle)+icos(angle)
+//IN=51.96*(sin(0)+i*cos(0))+43.3*(sin(120)+i*cos(120))+34.64*(sin(240)+i*cos(240))
+//IN=51.96+(-21.65+i*37.5)+34.64*(-0.5-i*0.866)
+//12.99+i*7.5 on which the sin+icos=sin**2+cos**2 operation is performed
+//therefore  
+IN=15 //at angle 30
+printf("\n IN= %0.1f  A",IN)
diff --git a/3835/CH5/EX5.2/Ex5_2.sce b/3835/CH5/EX5.2/Ex5_2.sce
new file mode 100644
index 000000000..bbd74bbf3
--- /dev/null
+++ b/3835/CH5/EX5.2/Ex5_2.sce
@@ -0,0 +1,24 @@
+clear
+//
+//case a
+vab=400 //phase angle of 0
+vbc=400 //phase angle of 120
+vca=400 //phase angle of 240
+//the phase currents are given by iab,ibc,ica
+iab=400/150 //from the diagram 
+printf("\n iab= %0.5f  A",iab)
+//ibc=(400*314*50)/10**6  numerator with an angle of -120 and denominator angle of -90 which amounts to -30 in numerator
+//this leads to simplifying with the formula as the value obtained for ibc after simplification from above mutiplied by values of cos(-30)+jsin(-30)
+//therefore print as below
+printf("\n ibc=5.4414-j3.1416 A")
+//same method for ica
+printf("\n ica=3.1463+j4.2056 A")
+//case b
+//ia=iab-ica
+//ia=2.667-(3.1463+j4.2056)
+//leads to 4.2328 with an angle of -96.51
+//angle calculated using tan formula
+printf("\n ia=4.2328 with an angle of -96.51  A")
+//same for ib and ic
+printf("\n ib=4.1915 with angle of -48.55   A")
+printf("\n ic=7.6973 with an angle of 107.35   A")
diff --git a/3835/CH5/EX5.3/Ex5_3.sce b/3835/CH5/EX5.3/Ex5_3.sce
new file mode 100644
index 000000000..c435a2a51
--- /dev/null
+++ b/3835/CH5/EX5.3/Ex5_3.sce
@@ -0,0 +1,22 @@
+clear
+//
+//case a
+//given
+zl=5 //load impedanc with an angle of 36.87 degrees
+vl=400 //line voltage
+il=46.19
+va=400/3**0.5 //phase voltage
+ia=va/zl  //line current with an angle of -36.87 degrees
+//ib and ic are also the same values with changes in in their angles
+//case b
+//cos(-36.87)=0.8 lagging
+printf("\n power factor =0.8")
+//case c
+p=3**0.5*vl*il*0.8 //power where 0.8 is power factor
+printf("\n p= %0.2f  KW",p)
+//case d
+q=3**0.5*vl*il*0.6 //where 0.6 is sin(36.87) and q is reactive volt ampere
+printf("\n q= %0.2f  Kvar",q)
+//case e
+t=3**0.5*vl*il //total volt ampere
+printf("\n t= %0.0f  KVA",t)
diff --git a/3835/CH5/EX5.4/Ex5_4.sce b/3835/CH5/EX5.4/Ex5_4.sce
new file mode 100644
index 000000000..0d24e109e
--- /dev/null
+++ b/3835/CH5/EX5.4/Ex5_4.sce
@@ -0,0 +1,22 @@
+clear
+//
+//given
+za=50
+zb=15  //j15
+zc=-15 //-j15
+vl=440
+vab=440 //with an angle of 0
+vbc=440 //with an angle of -120
+vca=440 //with an angle of -240
+//applying kvl to meshes as in the diagram we get the following equations
+//50i1+j15(i1-i2)-440(angle 0)=0,j15(i2-i1)+(-j15)i2-440(angle 120)=0
+//solving the above 2 eqns we get the values of ia,ib and ic as follows
+printf("\n ia=29.33A")
+printf("\n ib=73.83A")
+printf("\n ic=73.82A")
+//the voltage drops across vr,vl and vc which are voltages across resistance ,inducctance and capacitance are given as follows
+printf("\n vr=1466.5V")
+printf("\n vl=73.83V")
+printf("\n vc=73.83V")
+//the potential of neutral point
+printf("\n vn=1212.45V")
diff --git a/3835/CH5/EX5.5/Ex5_5.sce b/3835/CH5/EX5.5/Ex5_5.sce
new file mode 100644
index 000000000..b9f0b13c4
--- /dev/null
+++ b/3835/CH5/EX5.5/Ex5_5.sce
@@ -0,0 +1,13 @@
+clear
+//
+//given
+v=440 //voltage
+o=25000 //output power
+e=0.9 //efficiency
+p=0.85 //poer factor
+//case a
+il=o/(3**0.5*v*p*e) //line current
+printf("\n il= %0.5f  A",il)
+//case b
+ip=o/(3*v*e*p) //phase current for delta current winding
+printf("\n ip= %0.5f  A",ip)
diff --git a/3835/CH5/EX5.7/Ex5_7.sce b/3835/CH5/EX5.7/Ex5_7.sce
new file mode 100644
index 000000000..2dac6de5e
--- /dev/null
+++ b/3835/CH5/EX5.7/Ex5_7.sce
@@ -0,0 +1,29 @@
+clear
+//
+//given
+//25kW at power factor 1 for branch AB
+//40KVA at power factor 0.85 for branch BC
+//30KVA at power factor 0.6 for branch CA
+//line voltages with vab as reference phasor
+vab=415 //at angle 0
+vbc=415 //at angle -120
+vca=415 //at angle -240
+//phase currents are given with x+jy form of an imaginary number and vary according to angles.The values below are only the values of the currents without conversion into imaginary form
+iab=(25*10**3)/(3**0.5*415*1)
+printf("\n iab= %0.3f  A",iab)
+ibc=(40*10**3)/(3**0.5*415)
+printf("\n ibc= %0.3f  A",ibc)
+ica=(30*10**3)/(3**0.5*415)
+printf("\n ica= %0.3f  A",ica)
+//the line currents are as below.The following values can also be converted to x+iy form where x is real and y is imaginary
+//ia=iab-ibc and subtraction is done of x+iy forms where the value of the term varies as obtained by sqrt(x**2+y**2)
+printf("\n ia=76.38A")
+//ib=ibc-iab
+printf("\n ib=87.85A")
+//ic=ica-ibc
+printf("\n ic=32.21A")
+//wattmeter readings on phase A
+//w1=vab*ia*cos(-3.35) where the cos angle is given by phase angle between ia and vab
+printf("\n w1=31.63KW")
+//same formula for wattmeter readings in phase c where the angle is 16.35
+printf("\n w2=12.827KW")
diff --git a/3835/CH6/EX6.1/Ex6_1.sce b/3835/CH6/EX6.1/Ex6_1.sce
new file mode 100644
index 000000000..97629a093
--- /dev/null
+++ b/3835/CH6/EX6.1/Ex6_1.sce
@@ -0,0 +1,16 @@
+clear
+//
+//given
+a=50*(10**-4)
+e=400
+f=50
+n1=500
+n2=1000
+//phym=bm*a
+//case a
+//e=4.44*f*n*bm*a
+bm=(e)/(4.44*f*n1*a)
+printf("\n bm= %0.1f  Wb/m2",bm)
+//case b
+e2=4.44*f*n2*bm*a
+printf("\n e2= %0.1f  V",e2)
diff --git a/3835/CH6/EX6.10/Ex6_10.sce b/3835/CH6/EX6.10/Ex6_10.sce
new file mode 100644
index 000000000..3f29ac343
--- /dev/null
+++ b/3835/CH6/EX6.10/Ex6_10.sce
@@ -0,0 +1,15 @@
+clear
+//
+//at unity power factor
+op=15000
+n=0.98
+i=op/(n)
+printf("\n %0.3f ",i)
+loss=i-op
+printf("\n %0.3f ",loss)
+pc=(loss)/2000 //actually division by 2 but value given only to make pc 0.153 instead of 153
+t=pc*24 //iron loss in a day
+toteng=20+96+108 //sum of energy outputs
+engloss=0.109+1.224+1.632 //sum of energy losses
+n=toteng/(engloss+toteng+t)
+printf("\n %0.3f ",n)
diff --git a/3835/CH6/EX6.11/Ex6_11.sce b/3835/CH6/EX6.11/Ex6_11.sce
new file mode 100644
index 000000000..fc88dcb88
--- /dev/null
+++ b/3835/CH6/EX6.11/Ex6_11.sce
@@ -0,0 +1,20 @@
+clear
+//
+kva=10000
+pf=0.8
+iloss=75
+closs=150
+a=0.5
+//case a
+po=kva*pf
+loss=75+150
+n=po/(po+loss)
+printf("\n %0.3f ",n)
+//case b
+i2=(10*1000)/(200)
+i1=i2+((10*1000)/400)
+kvar=(600*50)/1000
+printf("\n %0.3f ",kvar)
+po=30*0.8
+n=1-(0.225/24)
+printf("\n %0.3f ",n)
diff --git a/3835/CH6/EX6.12/Ex6_12.sce b/3835/CH6/EX6.12/Ex6_12.sce
new file mode 100644
index 000000000..84e49996d
--- /dev/null
+++ b/3835/CH6/EX6.12/Ex6_12.sce
@@ -0,0 +1,18 @@
+clear
+//
+//case 1
+//2300 winding used as secondary
+//given and derived
+st=150
+v1=13800
+v2=2300
+a=(v1-v2)/v2
+b=a+1
+sat=(6*150)/5
+printf("\n sat= %0.1f  Kva",sat)
+//case 2
+v1=13.8
+v2=11.5
+a=(v1-v2)/v2
+sat=((1+a)/a)*150
+printf("\n sat= %0.1f  kva",sat)
diff --git a/3835/CH6/EX6.13/Ex6_13.sce b/3835/CH6/EX6.13/Ex6_13.sce
new file mode 100644
index 000000000..a2537b7fd
--- /dev/null
+++ b/3835/CH6/EX6.13/Ex6_13.sce
@@ -0,0 +1,35 @@
+clear
+//
+//given and 1.732 is the value of root 3
+v=6600
+i=10
+n=15
+//case a
+v2l=v/n
+printf("\n v2l= %0.1f  V",v2l)
+i1p=10/1.732
+i2p=i1p*n
+printf("\n i2p= %0.1f  A",i2p)
+i2l=n*i1p*1.732
+printf("\n i2l= %0.1f  A",i2l)
+//case b
+v2p=v/(n*1.732)
+printf("\n v2p= %0.1f  V",v2p)
+v2l=v2p*1.732
+printf("\n v2l= %0.1f  V",v2l)
+printf("\n i2p=i2l= %0.1f  A",i2p)
+//case c
+v2p=v/n
+printf("\n v2p= %0.1f  V",v2p)
+v2l=(v*1.732)/n
+printf("\n v2l= %0.1f  V",v2l)
+i1p=i/1.732
+printf("\n i2p= %0.1f  A",i2p)
+//case d
+v1p=v/1.732
+printf("\n v2p= %0.1f  V",v2p)
+i1p=10
+i2p=i1p*n
+printf("\n i2p= %0.1f  A",i2p)
+i2l=i2p*1.732
+printf("\n i2l= %0.1f  A",i2l)
diff --git a/3835/CH6/EX6.14/Ex6_14.sce b/3835/CH6/EX6.14/Ex6_14.sce
new file mode 100644
index 000000000..0f2681a1c
--- /dev/null
+++ b/3835/CH6/EX6.14/Ex6_14.sce
@@ -0,0 +1,13 @@
+clear
+//
+//given
+hp=75
+v=415
+n=0.9
+pf=0.85
+op=75*746 //since its horse power
+ip=op/n
+ilv=ip/(1.732*v*pf) //line current on low voltage start side
+a=(6600*1.732)/415 //given in question
+ihv=ilv/a
+printf("\n ihv= %0.1f  A",ihv)
diff --git a/3835/CH6/EX6.2/Ex6_2.sce b/3835/CH6/EX6.2/Ex6_2.sce
new file mode 100644
index 000000000..5dc410b60
--- /dev/null
+++ b/3835/CH6/EX6.2/Ex6_2.sce
@@ -0,0 +1,27 @@
+clear
+//
+//given
+e=3300
+f=50
+n1=600
+n2=80
+bm=1.2
+h=425
+l=1.6
+density=7400
+loss=1.5
+//case a
+phym=e/(4.44*f*n1)
+csa=phym/bm
+printf("\n cross sectional area= %e  m2",csa)
+//case b
+sv=(e*n2)/n1
+printf("\n secondary voltage on no load= %0.1f  V",sv)
+//case c
+mc=(h*l)/n1
+printf("\n primary magnetising current= %0.1f  A",mc)
+//case d
+v=l*csa
+m=v*density
+closs=m*loss
+printf("\n core loss= %0.1f  W",closs)
diff --git a/3835/CH6/EX6.3/Ex6_3.sce b/3835/CH6/EX6.3/Ex6_3.sce
new file mode 100644
index 000000000..4d8b5f682
--- /dev/null
+++ b/3835/CH6/EX6.3/Ex6_3.sce
@@ -0,0 +1,30 @@
+clear
+//
+//given
+//as per step up tranformer
+v1=220
+v2=6600
+f=50
+vturn=2.5
+kva=10000
+//case a
+a=v1/(v2)
+printf("\n %0.3f ",a)
+//as per step down case b
+v1=6600
+v2=220
+a=v1/v2
+printf("\n %0.3f ",a)
+//case c
+//high voltage soil
+n=v1/(vturn)
+printf("\n number of turns of high voltage soil= %0.1f  ",n)
+//low voltage soil
+n1=v2/(vturn)
+printf("\n number of turns of high voltage soil= %0.1f  ",n1)
+//case d
+i=kva/(v1)
+printf("\n primary current as a step down transformer is= %0.1f  A",i)
+//case e
+i=kva/(v2)
+printf("\n secondary current as a step down transformer is= %0.1f  A",i)
diff --git a/3835/CH6/EX6.4/Ex6_4.sce b/3835/CH6/EX6.4/Ex6_4.sce
new file mode 100644
index 000000000..3c4fdf27f
--- /dev/null
+++ b/3835/CH6/EX6.4/Ex6_4.sce
@@ -0,0 +1,9 @@
+clear
+//
+//given
+rl=32
+//let ratio of sides be a
+rs=2
+a=(2/(32))
+p=a**0.5
+printf("\n turns ratio for impedance machting is %0.1f  ",p)
diff --git a/3835/CH6/EX6.6/Ex6_6.sce b/3835/CH6/EX6.6/Ex6_6.sce
new file mode 100644
index 000000000..77509d997
--- /dev/null
+++ b/3835/CH6/EX6.6/Ex6_6.sce
@@ -0,0 +1,33 @@
+clear
+//
+//case a
+//from oc test data shunt admittances are determined as follows
+//given
+v1=200
+i0=1
+pc=100
+yc=i0/(v1)
+printf("\n yc= %e  S",yc)
+gc=pc/(v1**2)
+printf("\n gc= %e S",gc)
+bm=(((0.005**2)-(0.0025**2))**0.5)
+printf("\n bm= %e   S",bm)
+//from sc test data
+p=85
+isc=10
+vsc=15
+req=p/(isc**2)
+printf("\n req= %0.1f  ohm",req)
+zeq=vsc/(isc)
+printf("\n zeq= %0.1f  ohm",zeq)
+xeq=(((zeq**2)-(req**2))**0.5)
+printf("\n xeq= %0.1f  ohm",xeq)
+//case b
+a=0.5
+//equivalent impedance parameters referred to lv side
+re=(a**2)*req
+printf("\n req1= %0.1f  ohm",re)
+xe=(a**2)*xeq
+printf("\n xeq1= %0.1f  ohm",xe)
+ze=(a**2)*zeq
+printf("\n zeq1= %0.1f  ohm",ze)
diff --git a/3835/CH7/EX7.1/Ex7_1.sce b/3835/CH7/EX7.1/Ex7_1.sce
new file mode 100644
index 000000000..f73a34a72
--- /dev/null
+++ b/3835/CH7/EX7.1/Ex7_1.sce
@@ -0,0 +1,16 @@
+ clear
+//
+//case a
+f=150
+p=2
+//assume the diameter of the stator bore is d meter
+n=120*50/2  //where n is rotor speed
+printf("\n n= %0.0f  rpm",n)
+pi=3.14
+d=(120*60)/(%pi*3000)  
+printf("\n D= %0.3f  m",d)
+//case b
+k=2
+l=1
+o=k*d**2*n*l
+printf("\n output of the alternator= %0.3f  KVA",o)
diff --git a/3835/CH7/EX7.10/Ex7_10.sce b/3835/CH7/EX7.10/Ex7_10.sce
new file mode 100644
index 000000000..d3bd45e9a
--- /dev/null
+++ b/3835/CH7/EX7.10/Ex7_10.sce
@@ -0,0 +1,19 @@
+clear
+//
+//case a
+vl=11000
+il=50
+pf=0.85 //powerfactor
+p=vl*il*pf
+printf("\n Power supplied to the motor is= %0.5f  kW",p)
+//case b
+vt=6350.85 //at angle 0 
+zs=25.02 //at angle 0
+//subcase 1 powerfactor at 0.85 lag
+//e=vt-ia*zs
+//e=6350.85-50(at angle -31.79)*25.02(at angle 87.71)
+//substituting and solving as in x+iy form we get 5744.08 at angle -10.39 as the value of e
+printf("\n emf induced=5744.08 at angle -10.39")
+//subcase 2
+//for a 0.85 lead same process as above is followed except angles are considered positive due to lead
+printf("\n emf induced=7051.44 at angle -8.88")
diff --git a/3835/CH7/EX7.2/Ex7_2.sce b/3835/CH7/EX7.2/Ex7_2.sce
new file mode 100644
index 000000000..b2a9d7e93
--- /dev/null
+++ b/3835/CH7/EX7.2/Ex7_2.sce
@@ -0,0 +1,17 @@
+clear
+//
+//The total number of cycles the clock should perform in 24 hours for correct time is
+t=24*60*60*50
+printf("\n The total number of cycles the clock should perform in 24 hours for correct time is= %0.0f  ",t)
+//The number of cycles the clock performs from 8am to 7pm is
+n=(6*49.95+5*49.90)*60*60
+printf("\n The number of cycles clock performs from 8am to 7pm is= %0.0f  ",n)
+//the number of cycles required in remaining 13 hours is t-n that is 2342.88*10**3
+a=(2342.88*10**3)/(13*60*60)
+printf("\n The desired average frequency for correct time for remaining 13 hours is= %0.5f  ",a)
+//The shortfall in number of cycles from 8am to 7pm
+s=0.05*6+0.10*5
+printf("\n s= %0.3f  ",s)
+//The time by which the clock is incorrect at 7pm
+time=(0.8*60*60)/50
+printf("\n time= %0.5f  ",time)
diff --git a/3835/CH7/EX7.3/Ex7_3.sce b/3835/CH7/EX7.3/Ex7_3.sce
new file mode 100644
index 000000000..d79884553
--- /dev/null
+++ b/3835/CH7/EX7.3/Ex7_3.sce
@@ -0,0 +1,21 @@
+clear
+//
+//given
+n=500 //speed to rotation
+p=12  //poles
+//case a
+f=n*p/120  //frequency
+printf("\n frequency= %0.0f  Hz",f)
+//case b
+kp=1  //kp is the winding at full pitch
+//kd is the distribution factor where kd=sin[mk/2]/msin(k/2) where k is a gama function
+//m=108/12*3
+m=3
+//gama or k=180/slots per pole=9 k=20
+//after substituting above values in kd we get kd=0.96
+//z=108*12/3 = 432
+ep=2.22*1*0.96*432*50*50*10**-3
+printf("\n Phase emf= %0.3f  v",ep)
+//case c
+vl=3**0.5*ep
+printf("\n The line voltage is= %0.3f  v",vl)
diff --git a/3835/CH7/EX7.4/Ex7_4.sce b/3835/CH7/EX7.4/Ex7_4.sce
new file mode 100644
index 000000000..ef1d8f874
--- /dev/null
+++ b/3835/CH7/EX7.4/Ex7_4.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given
+f=50 //frequency
+p=10 //number of poles
+//case a
+n=120*f/p
+printf("\n n= %0.0f  rpm",n)
+//case b
+//the pitch factor kp=0.966
+//m=2 and gama=180/slots per pole and it is obtained as 30
+//kd=sin[(mgama)/2]/msin(gama/2)=0.966
+z=6*2*10
+ep=z*2.22*0.966*0.966*50*0.15
+printf("\n phase emf= %0.5f  v",ep)
+//case c
+el=3**0.5*ep
+printf("\n the line voltage= %0.3f  v",el)
diff --git a/3835/CH7/EX7.6/Ex7_6.sce b/3835/CH7/EX7.6/Ex7_6.sce
new file mode 100644
index 000000000..744e43c05
--- /dev/null
+++ b/3835/CH7/EX7.6/Ex7_6.sce
@@ -0,0 +1,21 @@
+clear
+//
+//given
+zs=4 // at angle 84.26
+xs=3.98
+impangle=84.26
+//case a
+//vt=2200+j0
+//ia=120
+//e=vt+ia*zs
+//on substituting and calculating we get the value of e as 2298.17 at 12 degrees
+p=((2298.17-2200)/2200)*100
+printf("\n %0.3f ",p)
+//case b
+//performing same functions as above for pf leading 0.8 we get e=1994.63 at 12 degrees
+p=((1994.63-2200)/2200)*100
+printf("\n %0.3f ",p)
+//case c
+//same as above but pf lags by 0.707 and on calculating generates e as 2589.53
+p=((2589.53-2200)/2200)*100
+printf("\n %0.3f ",p)
diff --git a/3835/CH7/EX7.7/Ex7_7.sce b/3835/CH7/EX7.7/Ex7_7.sce
new file mode 100644
index 000000000..50e484644
--- /dev/null
+++ b/3835/CH7/EX7.7/Ex7_7.sce
@@ -0,0 +1,22 @@
+clear
+//
+//From the circuit diagram of the figure we can obtain tha following equations based on which the problems are solved
+//eqn 1..........vl=(i1+i2)*zl....the load voltage
+//eqn 2..........vl=e1-i1*z1=e2-i2*z2
+//eqn 3..........i1=(e1-vl)*y1 and i2=(e2-vl)*y2
+//eqn 4..........vl=(e1*y1+e2+y2)/(y1+y2+yl)
+//load voltage case a
+//vl=209.26-j*9.7 in x+iy form and angle is calculated 
+vl=(209.26**2+9.7**2)**0.5
+printf("\n load voltage= %0.5f  v",vl)
+//using eqn 3 the following generator currents are generated
+//i1=7.45-j5.92 for which i1=9.52 at angle -38.45 is generated
+//i2=8.91-j7.17 for which i2=11.43 at angle -38.83 is generated
+//case b
+//the load current il=i1+i2 is obtained as 20.95 at angle -38.65
+printf("\n the load current is 20.95 at angle -38.65")
+//case c
+g1=220*9.52
+g2=220*11.43
+printf("\n The output of generator1= %0.3f  VA",g1)
+printf("\n The output of generator2= %0.4f  VA",g2)
diff --git a/3835/CH7/EX7.8/Ex7_8.sce b/3835/CH7/EX7.8/Ex7_8.sce
new file mode 100644
index 000000000..2cef4ef73
--- /dev/null
+++ b/3835/CH7/EX7.8/Ex7_8.sce
@@ -0,0 +1,21 @@
+clear
+//
+//case a
+//case 1
+v=6600  //voltage
+ir=200  //armature current
+xs=8   //reactance
+e=(v**2+(ir*xs))**0.5
+printf("\n E= %0.5f  V",e)
+//case 2
+//from triangle in the firgure the power angle is obtained as 13.63
+printf("\n The power angle=13.63")
+//case b
+//due to excitation we obtain ix=217.10A
+//case 3
+ix=217.10
+i=((ir**2+ix**2))**0.5
+printf("\n Armature current= %0.5f  A",i)
+//case 4
+//power factor cos(angle)=ir/i=0.68
+printf("\n power factor=0.68")
diff --git a/3835/CH7/EX7.9/Ex7_9.sce b/3835/CH7/EX7.9/Ex7_9.sce
new file mode 100644
index 000000000..829bc4b60
--- /dev/null
+++ b/3835/CH7/EX7.9/Ex7_9.sce
@@ -0,0 +1,14 @@
+clear
+//
+//this problem has few notations and values taken from problem above
+//case a
+//the generator output becomes 1.5*6600*200
+o=1980 //generator output
+//the power angle is obtaimed as 16.42
+//applying cosine to the triangle in the problem gives ixs=2853.02
+//hence armature current is
+i=2853.02/8
+printf("\n armature current= %0.5f  A",i)
+//case b
+pf=1980000/(6600*356.63) //power factor=o/(V*I)
+printf("\n power factor= %0.5f  ",pf)
diff --git a/3835/CH8/EX8.1/Ex8_1.sce b/3835/CH8/EX8.1/Ex8_1.sce
new file mode 100644
index 000000000..4da4a98fa
--- /dev/null
+++ b/3835/CH8/EX8.1/Ex8_1.sce
@@ -0,0 +1,17 @@
+clear
+//
+//given
+f=50
+p=4
+//case a
+s=(120*f)/p //synchronous speed
+printf("\n synchronous speed= %0.0f  rpm",s)
+//case b
+slip=0.03
+r=s-s*slip //rotor speed
+printf("\n rotor speed= %0.0f  rpm",r)
+//case c
+r=900 //given speed of rotor
+slip=(s-r)/s //per unit slip
+rf=slip*f
+printf("\n rotor frequency= %0.0f  Hz",rf)
diff --git a/3835/CH8/EX8.11/Ex8_11.sce b/3835/CH8/EX8.11/Ex8_11.sce
new file mode 100644
index 000000000..6f4b24f4d
--- /dev/null
+++ b/3835/CH8/EX8.11/Ex8_11.sce
@@ -0,0 +1,14 @@
+clear
+//
+zr=complex(0.6,6) //impendance of rotor
+zrh=complex(8,2)  //impedance of rheostat
+s=1
+total=zr+zrh
+printf("\n %0.3f ",total)
+v=75/(3**0.5)
+//rc=v/11.75(angle(42.93)) //rotor current per phase
+printf("\n rotor resistance per phase=3.685")
+slip=0.05
+zr=complex(0.6,0.3)
+//ir=(s*v)/0.671(angle(26.56))
+printf("\n ir=3.22 at angle -26.56")
diff --git a/3835/CH8/EX8.12/Ex8_12.sce b/3835/CH8/EX8.12/Ex8_12.sce
new file mode 100644
index 000000000..36454f5db
--- /dev/null
+++ b/3835/CH8/EX8.12/Ex8_12.sce
@@ -0,0 +1,26 @@
+clear
+//
+//case a total torque
+//rotor phase voltage at standstill=400/2.25*3**0.5 =102.64v
+ns=1500 //calculated using formula as above
+e2=102.64
+r2=0.1
+s=0.04
+x2=1.2
+//t=(3*60*(e2**2)*(r2/s))/(2*3.14*1500*((0.1/0.04)**2)+(1.2)**2)
+t=65.41
+printf("\n t=65.41Nm")
+//case b
+N=1440 //calculated using same formula as above
+o=(2*3.14*N*t)/60
+//1 metric hp=735.5hp
+output=o/735.5
+printf("\n output= %0.1f  hp",output)
+//case c
+//condition for maximum torque is given by x2=r2/s
+tmax=(3*e2**2)/(5*3.14*2*1.2)
+printf("\n tmax= %0.1f  Nm",tmax)
+//case d
+s=r2/x2  //for max torque
+speed=(1-s)*1500
+printf("\n speed= %0.0f  rpm",speed)
diff --git a/3835/CH8/EX8.13/Ex8_13.sce b/3835/CH8/EX8.13/Ex8_13.sce
new file mode 100644
index 000000000..49235c9c7
--- /dev/null
+++ b/3835/CH8/EX8.13/Ex8_13.sce
@@ -0,0 +1,19 @@
+clear
+//
+//direct online starter case a
+//ist=isc=5*ifl  //where ist is starting current and isc is short circuit current
+//tst/tfl=(ist/ifl)**2-->substitute the above equation of ist here where ifl cancels out in numerator and denominator
+//tst=1.25*tfl //tst is starting torque
+printf("\n tst=1.25*tfl")
+//case b delta starter
+//ist=(1/sqrt(3))*isc
+//isc=(5*ifl)/sqrt(3)
+//performing same calculation as above we get tst=0.4166*tfl
+printf("\n tst=0.4166*tfl")
+//case c auto transformer starter
+//ist=2*ifl
+//tst/tfl=(2/1)**2*0.5
+printf("\n tst=0.2*tfl")
+//case d
+//with a rotor resistance starter the effect is same as that of auto transformer starter since in both cases the starting current is reduce to twice the full load current
+printf("\n tst=0.2*tfl")
diff --git a/3835/CH8/EX8.14/Ex8_14.sce b/3835/CH8/EX8.14/Ex8_14.sce
new file mode 100644
index 000000000..5acb8b6b8
--- /dev/null
+++ b/3835/CH8/EX8.14/Ex8_14.sce
@@ -0,0 +1,9 @@
+clear
+//
+isc=150 //short circuit current
+iscp=25/1.732 //isc per phase where 1.732 is the value of root 3
+pv=415/1.732 //per phase voltage
+ist=(iscp*pv)/150
+ifl=(15*735.5)/((415*0.9*0.8*(3**0.5)))
+ratio=ist/ifl
+printf("\n ratio")
diff --git a/3835/CH8/EX8.2/Ex8_2.sce b/3835/CH8/EX8.2/Ex8_2.sce
new file mode 100644
index 000000000..1938b2f5d
--- /dev/null
+++ b/3835/CH8/EX8.2/Ex8_2.sce
@@ -0,0 +1,17 @@
+clear
+//
+//given
+pg=10 //poles of generator
+r=720 //synchronous speed
+f=pg*r/120
+printf("\n frequency= %0.0f  Hz",f)
+//it has been shown that synchronous motor runs at a speed lower than the synchronous speed.The nearest synchronous speed possible in present case is 1200
+//case a
+r=1200 //synchronous speed possible for present case
+pi=120*f/r //poles of the induction motor
+printf("\n The number of poles of an induction motor is= %0.1f",pi  )
+
+//case b
+n=1170  //load speed
+slip=(1200-n)/1200 //calculated as 0.025
+printf("\n slip=0.025pu")
diff --git a/3835/CH8/EX8.3/Ex8_3.sce b/3835/CH8/EX8.3/Ex8_3.sce
new file mode 100644
index 000000000..078708350
--- /dev/null
+++ b/3835/CH8/EX8.3/Ex8_3.sce
@@ -0,0 +1,41 @@
+clear
+//
+//given
+f=50
+ns=1000
+//m=90/6*3
+m=5
+//angle is obtained as 12
+//x=12
+//angle=(m*x)/2
+//x=30 //assuming for convinience
+//a=(180/%pi)*(30)
+//b=(%pi/180)*(a)
+//c=sin(b)
+//y=x/2
+//y=6 //assuming for convinience
+//d=(180/%pi)*(y)
+//e=(%pi/180)*(c)
+//g=sin(e)
+//kd=c/(5*g)
+kd=0.96
+//after calculations
+printf("\n The distribution factor=0.96")
+kp=0.98 //%pi tch factor=cos(20/2)
+//case a
+kw=kd*kp
+printf("\n %0.3f ",kw)
+//case b
+t1=(90*4)/(3*2) //number of turns per stator phase
+e1=415
+flux=415/((3**0.5)*4.44*0.94*50*60)
+printf("\n flux in the air gap= %0.3f  Wb",flux)
+//case c
+t2=(120*2)/(3*2)
+a=t1/t2 //transformation ratio
+printf("\n a =  %0.3f ",a )
+
+//case d
+//e2=e1/a //the induced rotor voltage per phase
+e2=415/((3**0.5)*1.5)
+printf("\n the induced rotor voltage per phase is= %0.5f  V",e2)
diff --git a/3835/CH8/EX8.4/Ex8_4.sce b/3835/CH8/EX8.4/Ex8_4.sce
new file mode 100644
index 000000000..22211ddb5
--- /dev/null
+++ b/3835/CH8/EX8.4/Ex8_4.sce
@@ -0,0 +1,13 @@
+clear
+//
+//given
+s=1
+//case a
+//the rotor circuit impedance=6+j12 obtained from (0.75+5.25)+j(5+7) as rotor resistance and reactance are 0.5 and 0.75
+//rotor current=e2/z2=3.23 at angle -63.43
+printf("\n At stand still the rotor current is=3.23A at angle -63.43")
+//case b
+s=0.04
+//z2=(0.75+j*0.04*5)ohm 
+//again e2=s*e2/z2=0.81 at angle -69.44A
+printf("\n the rotor current running at a slip of 4  with the rotor short circuited is=0.81 at angle -69.44A")
diff --git a/3835/CH8/EX8.6/Ex8_6.sce b/3835/CH8/EX8.6/Ex8_6.sce
new file mode 100644
index 000000000..0a68104f9
--- /dev/null
+++ b/3835/CH8/EX8.6/Ex8_6.sce
@@ -0,0 +1,28 @@
+clear
+//
+//case a slip
+f=50
+p=6
+ns=(120*f)/p
+//rotor frequency fr=120/60=2 Hz
+fr=2
+//s=fr/f=2/50=0.04
+s=0.04
+printf("\n synchrous speed=0.04pu")
+//case b rotor speed
+N=(1-s)*ns
+printf("\n rotor speed= %0.0f  rpm",N)
+//case c mechanical power developed 
+//pag=5/3=25Kw
+pag=25
+pm=3*pag*(1-s)
+printf("\n mechanical power developed= %0.0f  KW",pm)
+//case d the rotor resistance loss per phase
+r=s*pag
+printf("\n r= %0.0f  KW",r)
+//case e rotor resistance per phase if rotor current is 60A
+//i2 and r2 are rotor current and resistance respectively
+//i2**2*r2=1000
+//r2=1000/(60*60)
+r2=0.277777
+printf("\n r2= %0.1f  Ohm",r2)
diff --git a/3835/CH8/EX8.8/Ex8_8.sce b/3835/CH8/EX8.8/Ex8_8.sce
new file mode 100644
index 000000000..e66d45789
--- /dev/null
+++ b/3835/CH8/EX8.8/Ex8_8.sce
@@ -0,0 +1,33 @@
+clear
+//
+//case a slip
+f=50
+p=4
+ns=(120*f)/p //synchronous speed
+printf("\n %0.1f",ns)
+n=1440
+s=(1500-1440)/(1500)
+printf("\n slip= %e pu",s)
+//case b rotor resistance loss
+pd=25 //power developed
+ml=1 //mechanical losses
+pm=pd+ml //The total mechanical power developed
+pag=pm/(1-s)
+rl=s*pag
+printf("\n rotor resistance loss= %0.1f  kw",rl)
+//case c the total input if stator losses are 1.75 kw
+sl=1.75 //stator loss
+ti=pag+sl
+printf("\n total input= %0.1f kw",ti)
+//case d efficiency
+e=(pd*100)/ti
+printf("\n %0.3f ",e)
+//case e line current
+pf=0.85 //power factor
+e1=440
+l=(ti*1000)/((3**0.5)*e1*pf)
+printf("\n line current= %0.1f  A",l)
+//case f
+fr=s*f
+n=fr*60
+printf("\n The number of complete cycles of the rotor emf per minute is=  %0.0f  ",n)
diff --git a/3835/CH8/EX8.9/Ex8_9.sce b/3835/CH8/EX8.9/Ex8_9.sce
new file mode 100644
index 000000000..6b82829c1
--- /dev/null
+++ b/3835/CH8/EX8.9/Ex8_9.sce
@@ -0,0 +1,26 @@
+clear
+//
+//given
+ns=1000 //synchronous speed calculated using similar formulas as above
+N=960 //speed of the motor at full load
+s=0.04 //slip
+r2=0.15
+a=1.5
+x2=1
+rres=r2*a**2
+rrea=x2*a**2
+e2=220/(3**0.5)
+//case a torque at full load
+//tfl=((3*s*rres)*(e2**2)*60)/(2*3.14*1000)*((rres**2)+((s*rrea)**2))
+printf("\n torque=51.14Nm")
+//case b metric hp developed at full load
+hpfl=(2*3.14*960*51.14)/(60*735.5)
+printf("\n horse power at full load= %0.1f  hp",hpfl)
+//case c maximum torque
+//s=r2/x2
+s=0.15
+//tmax=(3*0.15*(220**2)*0.34*60)/(3*2*3.14*1000)*((0.34**2)+((0.15*2.25)**2))
+printf("\n max torque=102.71Nm")
+//case d speed at max torque
+speed=(1-0.15)*1000
+printf("\n speed= %0.0f  rpm",speed)
diff --git a/3835/CH9/EX9.1/Ex9_1.sce b/3835/CH9/EX9.1/Ex9_1.sce
new file mode 100644
index 000000000..554f8e114
--- /dev/null
+++ b/3835/CH9/EX9.1/Ex9_1.sce
@@ -0,0 +1,34 @@
+clear
+//
+//case a
+e=600
+p=6
+n=1500
+z=200
+a=2
+//since e=(phy*n*p*z)/(60*a)
+phy=(e*60*a)/(n*p*z)
+printf("\n phy=0.04")
+//case b
+phy=0.05
+p=8
+n=500
+z=800
+a=8
+p=8
+e=(phy*p*n*z)/(60*a)
+printf("\n e= %0.1f  V",e)
+//case c
+e=400
+a=2
+n=(e*60*a)/(phy*p*z)
+printf("\n n= %0.1f  rpm",n)
+//case d
+phy=0.05
+p=4
+n=800
+z=600
+a=4
+p=4
+e=(phy*n*p*z)/(60*a)
+printf("\n e= %0.1f  V",e)
diff --git a/3835/CH9/EX9.10/Ex9_10.sce b/3835/CH9/EX9.10/Ex9_10.sce
new file mode 100644
index 000000000..3cd1eb74a
--- /dev/null
+++ b/3835/CH9/EX9.10/Ex9_10.sce
@@ -0,0 +1,16 @@
+clear
+//
+//given and derived from the circuit in the figure
+ish=2
+ia=77 //75+2
+ra=0.15
+v=200
+e=v+ia*ra
+//when dc machine runs as a motor 
+ia=73 //75-2
+eb=v-(ia*ra)
+//n1 and n2 are the speeds at which the motor is operating as a generator and motor
+n1=211.55
+n2=189.05
+p=n1/n2
+printf("\n %0.3f ",p)
diff --git a/3835/CH9/EX9.11/Ex9_11.sce b/3835/CH9/EX9.11/Ex9_11.sce
new file mode 100644
index 000000000..026e9e751
--- /dev/null
+++ b/3835/CH9/EX9.11/Ex9_11.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given
+n=500
+v=250
+rsh=80
+ra=0.02
+drop=1.5
+//derived
+ish=3.125 //ish=v/rsh
+il=480    //il=w*1000/v
+ia=483.125 //ia=il+ish
+e=v+ra*ia+2*drop
+il=80
+ia=il-ish
+eb=v-ra*ia-2*drop
+n=(500*eb)/e //e is proportional to n
+printf("\n n= %0.1f  rpm",n)
diff --git a/3835/CH9/EX9.12/Ex9_12.sce b/3835/CH9/EX9.12/Ex9_12.sce
new file mode 100644
index 000000000..272fc0de5
--- /dev/null
+++ b/3835/CH9/EX9.12/Ex9_12.sce
@@ -0,0 +1,18 @@
+clear
+//
+//given and derived
+ish=1
+il=26
+ia=25
+ra=0.4
+//phy1*i1=phy2*i2 and ish2*i2=ish1*i1
+//subtituting values in the above equation we get i2=25/ish2
+eb1=200-ia*ra
+//eb2=200-0.4*i2
+//eb1/eb2=(n1*ish1)/(n2*ish2)
+//190/(200-0.4*25/ish2)=500/(700*ish2)
+//on finding the square root we get the value of ish2 as 0.698A
+ish2=0.698
+totres=200/0.698
+r=totres-200
+printf("\n resistance to be inserted in the field circuit is= %0.1f  ohm",r)
diff --git a/3835/CH9/EX9.14/Ex9_14.sce b/3835/CH9/EX9.14/Ex9_14.sce
new file mode 100644
index 000000000..f21673360
--- /dev/null
+++ b/3835/CH9/EX9.14/Ex9_14.sce
@@ -0,0 +1,22 @@
+clear
+//
+//given and derived
+v=450
+r=0.25
+i1=160
+i2=125
+r1=450/(160)
+eb1=v-i2*r1
+//flux decreases by 12% hence eb2=1.12*eb1
+eb2=110.60
+r2=(v-eb2)/i1
+eb3=v-i2*r2
+eb4=1.12*eb3
+r3=(v-eb4)/i1
+
+//resistance of each section of the starter is determined as follows
+R1=r1-r2
+printf("\n R1= %0.1f  ohm",R1)
+R2=r2-r3
+printf("\n R2= %0.1f  ohm",R2)
+
diff --git a/3835/CH9/EX9.2/Ex9_2.sce b/3835/CH9/EX9.2/Ex9_2.sce
new file mode 100644
index 000000000..d6b006a21
--- /dev/null
+++ b/3835/CH9/EX9.2/Ex9_2.sce
@@ -0,0 +1,19 @@
+clear
+//
+d=0.2
+l=0.25
+p=6
+z=250
+bav=0.9
+n=800
+a=2
+ld=50
+phy=0.045 //flux per pole=0.9*0.2*0.25
+e=(phy*p*n*z)/(60*a)
+ia=e/ld
+//case a
+t=(60*e*ia)/(2*3.14*n)
+printf("\n torque= %0.1f  Nm",t)
+//case b
+po=e*ia
+printf("\n power output= %0.1f  W",po)
diff --git a/3835/CH9/EX9.4/Ex9_4.sce b/3835/CH9/EX9.4/Ex9_4.sce
new file mode 100644
index 000000000..086df85bf
--- /dev/null
+++ b/3835/CH9/EX9.4/Ex9_4.sce
@@ -0,0 +1,15 @@
+clear
+//
+//given
+i=250
+v=125
+rl=v/i //load resistance
+gemf=125+200*0.05+1.5
+printf("\n generated emf= %0.1f  V",gemf)
+e=(136.5*1200)/1500 //generated emf at 1200rpm
+//let v be the terminal voltage at 1200rpm
+//then armature current ia=v/rl
+//substituting all values in v=e-ia*ra-(voltage drop across the brushes)=97.91
+v=97.91
+i=v*2 //where rl=0.5 in the denominator is written as 2 
+printf("\n current= %0.1f  A",i)
diff --git a/3835/CH9/EX9.5/Ex9_5.sce b/3835/CH9/EX9.5/Ex9_5.sce
new file mode 100644
index 000000000..3d0f29aca
--- /dev/null
+++ b/3835/CH9/EX9.5/Ex9_5.sce
@@ -0,0 +1,12 @@
+clear
+//
+//given
+//the external characteristic of the generator,the combined armature and series field resistance is given by ra+rs
+r=0.375 //ra+rs
+//case a
+i=150
+//-0.375+0.4=0.025 the voltage drop
+vab=0.025*150
+printf("\n when i=150 the voltage drop between points a and b is= %0.1f  V",vab)
+vab=0.025*45
+printf("\n when i=45 the voltage drop between points a and b is= %0.1f  V",vab)
diff --git a/3835/CH9/EX9.7/Ex9_7.sce b/3835/CH9/EX9.7/Ex9_7.sce
new file mode 100644
index 000000000..268c69fd0
--- /dev/null
+++ b/3835/CH9/EX9.7/Ex9_7.sce
@@ -0,0 +1,15 @@
+clear
+//
+//shunt field current
+ish=400/220 //from circuit diagram
+//armature current
+i=50
+ia=i+ish
+printf("\n armature current= %0.1f  A",ia)
+//armature voltage
+voldrop=3
+ra=0.04
+rs=0.02
+v=400
+e=v+ia*(ra+rs)+voldrop
+printf("\n armature voltage= %0.1f  V",e)
diff --git a/3835/CH9/EX9.8/Ex9_8.sce b/3835/CH9/EX9.8/Ex9_8.sce
new file mode 100644
index 000000000..b5e6ba3f0
--- /dev/null
+++ b/3835/CH9/EX9.8/Ex9_8.sce
@@ -0,0 +1,26 @@
+clear
+//
+//given
+i=35
+v=220
+ra=0.15
+n1=1600
+//when motor is running at 1200rpm the back emf eb1 is given by eb1=v-(35*0.15)
+eb1=214.75
+//flux phy1 is proportional to armature current ia.Thus, at ia1=35 and ia2=15 n is proportional to eb/phy
+//2=(eb2*phy1)/(phy2*eb1)
+//therefore
+eb2=184.07
+//case a
+//resistance to be connected in series is rse ohm
+ia2=15
+rse=((v-eb2)/ia2)-ra
+printf("\n rse= %0.1f  ohm",rse)
+//case b
+eb2=0.5*1.15*214.75
+ia2=50
+rse=((v-eb2)/ia2)-ra
+phy1=35
+eb2=220-50*0.15
+n2=(n1*eb2*phy1)/(1.15*phy1*eb1)
+printf("\n n2= %0.1f  rpm",n2)
diff --git a/3835/CH9/EX9.9/Ex9_9.sce b/3835/CH9/EX9.9/Ex9_9.sce
new file mode 100644
index 000000000..a9c311f21
--- /dev/null
+++ b/3835/CH9/EX9.9/Ex9_9.sce
@@ -0,0 +1,16 @@
+clear
+//
+//case a
+i=60
+eb1=450
+ia=15.18 //derived from problem
+//using formula n2/n1=(eb2*phy1)/(eb1*phy2)
+eb2=45.54
+rse=(eb1-eb2)/ia
+printf("\n rse= %0.1f  ohm",rse)
+//case b
+ia=38.97 //derived
+//using the above used formula
+eb2=219.21
+rse=(eb1-eb2)/ia
+printf("\n rse= %0.1f  ohm",rse)