# Chapter13:SUPERCONDUCTIVITY¶

## Ex13.1:pg-357¶

In [9]:
#example 1
#to calculate value of Temperature
import math
Bc=105.0*10**3 #magnetic field in amp/m
Bo=150.0*10**3 #critical field of the metal in amp/m
Tc=9.2 #critical temperature of the metal in K
T=Tc*math.sqrt(1-(Bc/Bo))#temperature
print"\n the value of temperature is",round(T,3),"K"

 the value of temperature is 5.039 K


## Ex13.2:pg-357¶

In [1]:
#example 2
#to calculate temperature
import math
Tc=7.18 #critical temperature in K
Bc=4.5*10**3  #critical field in A/m
Bo=6.5*10**3 #critical magnetic field in A/m
T=Tc*math.sqrt(1-(Bc/Bo))# temperature
print"\n the temperature is",round(T,3),"K"
#to calculate critical current density at that temperature
r=1*10**-3 #diameter of the wire in mm
TJc=(Bc*2*math.pi*r)/(math.pi*r**2)# critical current density
print"\n the critical current density at that temperature is","{:.3e}".format(TJc),"A/m^2"

 the temperature is 3.983 K

the critical current density at that temperature is 9.000e+06 A/m^2