Chapter 18:Magnetism

Ex18.1:pg-901

  #Example 18_1
import math 
  
#To find the force on the wire
b=2*10**-4        #Units in T
i=20           #Units in A
l=0.3          #Units in meters
theta=53                #Units in degrees
thetaa=math.sin(theta*math.pi/180)        #Units in Radians     
f=b*i*l*thetaa               #Units in N
print "The force on the wire is F=",round(f,9)," N"

The force on the wire is F= 0.000958363  N

Ex18.2:pg-902

  #Example 18_2
import math 
  
  #To find the magnitude of the magnetic field
m=1.67*10**-27          #Units in Kg
v=10**6           #Units in meters/sec
r=4*10**-2            #Units in Meters
q=1.6*10**-19           #Units in C or eV
b=(m*v)/(r*q)           #Units in T
print "The magnitude of magnetic field is B=",round(b,4)," T"

The magnitude of magnetic field is B= 0.2609  T

Ex18.3:pg-903

  #Example 18_3
import math  
#To show that the particles does not deflect from its straight line path
print "The magnetic field exerts a force of q*v*B upwards on the particle.\nThe particle doesnot deflect because the two forces are equal\nHence v=(E/B)\nA particle with this speed will pass through the region of the crossfields and undeflected"

The magnetic field exerts a force of q*v*B upwards on the particle.
The particle doesnot deflect because the two forces are equal
Hence v=(E/B)
A particle with this speed will pass through the region of the crossfields and undeflected

Ex18.4:pg-903

  #Example 18_4
import math  
#To calculate the value of B at a radial distance of 5 cm
u=4*math.pi*10**-7        #Units in T m/A
i=30         #Units in A
r=0.05           #Units in Meters
b=(u*i)/(2*math.pi*r)           #Units in T
b=b*10**4            #Units in G
print "The value of B is=",round(b,2)," G"

The value of B is= 1.2  G

Ex18.5:pg-904

  #Example 18_5
import math
  
#To find the magnetic moment of hydrogen atom
r=0.53*10**-10        #Units in meters
a=math.pi*r**2         #Units in meters**2
q=1.6*10**-19            #Units in C
f=6.6*10**15          #Units in sec**-1
i=q*f            #Units in A
u=i*a            #Units in A meter**2
print "The magnetic moment of Hydrogen atom is="
print round(u,27)
print "A meters**2"

The magnetic moment of Hydrogen atom is=
9.319e-24
A meters**2