Chapter 8: Electromagnetism

Example 2, page no. 93

In [1]:
from __future__ import division
import math
#initializing  the  variables:
B  =  0.9;#  in  tesla
I  =  20;#  in  Amperes
l  =  0.30;#  in  m
alpha  =  30;#  in  degree
u0  =  4*math.pi*1E-7;

#calculation:
F1  =  B*I*l
F2  =  B*I*l*math.sin(alpha*math.pi/180)

#Results
print  "\n\nResult\n\n"
print  "\n  (a)Force  when  the  conductor  is  at  right  angles  to  the  field  =  ",F1,"  N\n"
print  "\n  (b)Force  when  the  conductor  is  at  30°  angle  to  the  field  =  ",F2,"  N\n"


Result



  (a)Force  when  the  conductor  is  at  right  angles  to  the  field  =   5.4   N


  (b)Force  when  the  conductor  is  at  30°  angle  to  the  field  =   2.7   N

Example 3, page no. 94

In [2]:
from __future__ import division
import math
#initializing  the  variables:
F  =  1.92;#  in  newton
B  =  1.2;#  in  tesla
l  =  0.40;#  in  m
u0  =  4*math.pi*1E-7;

#calculation:
I  =  F/(B*l)

#Results
print  "\n\nResult\n\n"
print  "\n  (a)Current  I  =  ",I,"  Amperes(A)\n"


Result



  (a)Current  I  =   4.0   Amperes(A)

Example 4, page no. 95

In [3]:
from __future__ import division
import math
#initializing  the  variables:
r  =  0.06;#  in  m
I  =  10;#  in  Amperes
l  =  0.35;#  in  m
Phi  =  0.5E-3;#  in  Wb
u0  =  4*math.pi*1E-7;

#calculation:
A  =  math.pi*r*r
B  =  Phi/A
F  =  B*I*l

#Results
print  "\n\nResult\n\n"
print  "\n  (a)Force  F  =  ",round(F,2),"  N\n"


Result



  (a)Force  F  =   0.15   N

Example 6, page no. 95

In [4]:
from __future__ import division
import math
#initializing  the  variables:
N1  =  1;#  for  a  single-turn  coil
N2  =  300;#  no.  of  turns
b  =  0.024;#  in  m
B  =  0.8;#  in  Tesla
I  =  0.05;#  in  Amperes
l  =  0.030;#  in  m
u0  =  4*math.pi*1E-7;

#calculation:
#For  a  single-turn  coil,
F1  =  N1*B*I*l
#for  a  coil  wound  with  300  turns.
F2  =  N2*B*I*l

#Results
print  "\n\nResult\n\n"
print  "\n  (a)For  a  single-turn  coil,  force  on  each  coil  side  =  ",F1,"  N\n"
print  "\n  (b)For  a  300-turn  coil,  force  on  each  coil  side  =  ",F2,"  N\n"


Result



  (a)For  a  single-turn  coil,  force  on  each  coil  side  =   0.0012   N


  (b)For  a  300-turn  coil,  force  on  each  coil  side  =   0.36   N

Example 7, page no. 98

In [5]:
from __future__ import division
import math
#initializing  the  variables:
Q  =  1.6E-19;#  in  Coulomb
v  =  3E7;#  in  m/s
B  =  18.5E-6;#  in  Tesla
u0  =  4*math.pi*1E-7;

#calculation:
F  =  Q*v*B

#Results
print  "\n\nResult\n\n"
print  "\n  Force  exerted  on  the  electron  in  the  field.  =  ",(F/1E-17),"E-17  N\n"


Result



  Force  exerted  on  the  electron  in  the  field.  =   8.88 E-17  N