Chapter 19:Electromagnetic Induction

Ex19.1:pg-938

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"
The flux in the room is Phi= 0.00012  T meters**2

Ex19.2:pg-939

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"
The average emf Induced is emf= 1.0  V

Ex19.3:pg-939

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"
The emf generated is emf= 50.0  V

Ex19.5:pg-939

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"
The time constant is L/R= 0.0833  Sec
 The energy stored is= 1.0  J

Ex19.6:pg-940

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"
The emf induced in the rod is emf= 0.000542  V

Ex19.7:pg-940

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"
The back emf developed is EMF= 104.0  V