# Chapter 15 :Electromagnetic Induction¶

## Example 15.3 , Page no:90¶

In [1]:
import math
from __future__ import division

#initialisation of variables
l=5*0.305; #converting ft to metre
v=40*0.447; #converting mile/hr to m/sec
B=3*10**-5; #magnetic field in Tesla

#CALCULATIONS
ve=B*l*v; #calculating potential difference

#RESULTS
print"Potential difference in Volt =",round(ve,5);

Potential difference in Volt = 0.00082


## Example 15.4 , Page no:91¶

In [2]:
import math
from __future__ import division

#initialisation of variables
i=0.707*10; #current in Ampere
r=20; #resistance in Ohm

#CALCULATIONS
p=i*i*r; #calculating power dissipated

#RESULTS
print"Power dissipated in Watt =",round(p,3);

Power dissipated in Watt = 999.698


## Example 15.5 , Page no:91¶

In [3]:
import math
from __future__ import division

#initialisation of variables
r=5; #resistance in ohm
p=1000; #power in Watt
va=100; #potential diff in Volt for a
vb=100000; #potential diff in volt for b

#CALCULATIONS
ia=p/va; #calculating current
ib=p/vb; #calculating current
ha=ia*ia*r; #heat in Watt
hb=ib*ib*r; #heat in Watt

#RESULTS
print"Heat produced by a in Watt =",round(ha,3);
print"Heat produced by b in Watt =",round(hb,4);

Heat produced by a in Watt = 500.0
Heat produced by b in Watt = 0.0005


## Example 15.6 , Page no:91¶

In [4]:
import math
from __future__ import division

#initialisation of variables
i1=3; #current in Ampere
n2=500; #no. of turns
n1=100; #no. of turns
v1=120; #potential diff in volt

#CALCULATIONS
v2=(n2*v1)/n1; #calculating v2
i2=(n1*i1)/n2; #calculating i2

#RESULTS
print"Voltage in volt =",round(v2,3);
print"Current in Ampere =",round(i2,3);

Voltage in volt = 600.0
Current in Ampere = 0.6


## Example 15.7 , Page no:91¶

In [5]:
import math
from __future__ import division

#initialisation of variables
p=10000; #power in Watt
v1=5000; #potential diff in volt
v2=240; #voltage in volt

#CALCULATIONS
i2=p/v2; #calculating i2
v=v1/v2;

#RESULTS
print"Ratio of turns =",round(v,3);
print"Maximum current in Ampere =",round(i2,3);

Ratio of turns = 20.833
Maximum current in Ampere = 41.667


## Example 15.8 , Page no:92¶

In [6]:
import math
from __future__ import division

#initialisation of variables
r=100; #resistance in ohm
v1=120; #potential diff in Volt
n2=50; #no. of turns
n1=200; #no. of turns

#CALCULATIONS
v2=(n2*v1)/n1; #potential diff in volt
i2=v2/r; #calculating current
i1=(n2/n1)*i2; #calculating current

#RESULTS
print"Current in primary circuit in Ampere =",round(i1,3);

Current in primary circuit in Ampere = 0.075