In [1]:

```
import math #Example19_1
#To find the flux in the room
l=4 #Units in meters
b=0.8 #Units in meters
theta=20 #Units in degrees
a=l*b #Units in meters**2
b=4*10**-5 #Units in T
thetaa=math.cos(theta*math.pi/180) #Units in radians
phi=b*thetaa*a #Units in T meters**2
print "The flux in the room is Phi=",round(phi,5)," T meters**2"
```

In [2]:

```
import math #Example19_2
#To find how large is the average EMF induced
b=0.5 #Units in T
a=4*10**-4 #Units in meters**2
phi2=b*a #Units in Wb
phi1=0 #Units in Wb
deltaPHI=phi2-phi1 #Units in Wb
n=100.0 #Units in Constant
deltaT=2.0*10**-2 #Units in sec
emf=(n*deltaPHI)/deltaT #Units in V
print "The average emf Induced is emf=",round(emf)," V"
```

In [3]:

```
import math #Example19_3
#To findout how large an emf is generated
m=0.5 #Units in H
i=1 #Units in A
t=0.01 #Units in sec
emf=m*(i/t) #Units in V
print "The emf generated is emf=",round(emf)," V"
```

In [5]:

```
import math #Example19_5
#To find the time constant of the circuit and the final energy stored
l=0.5 #Units in H
r1=2 #Units in Ohms
r2=4 #Units in Ohms
r=r1+r2 #Units in Ohms
l_r=l/r #Units in sec
i=2 #Units in A
ene=0.5*l*i**2
print "The time constant is L/R=",round(l_r,4)," Sec\n The energy stored is=",round(ene)," J"
```

In [6]:

```
import math #Example19_6
#To find the emf induced in the rod
b=0.6*10**-4 #Units in T
v=3 #Units in meters/sec
d=5 #Units in meters
theta=53 #Units in degrees
thetaa=math.cos(theta*math.pi/180) #Units in radians
emf=b*v*d*thetaa #Units in V
print "The emf induced in the rod is emf=",round(emf,6)," V"
```

In [3]:

```
import math #Example19_7
#To calculate the Back emf developed
i=3 #Units in A
r=2.0 #Units in Ohms
v=110.0 #Units in Ohms
e=v-(i*r) #Units in V
print "The back emf developed is EMF=",round(e)," V"
```