# 9: Superconductivity¶

## Example number 1, Page number 9-22¶

In [2]:
#importing modules
import math
from __future__ import division

#Variable declaration
Hc=1*10**5;    #critical magnetic field(A/m)
T=8;           #temperature(K)
H0=2*10**5;    #critical magnetic field(A/m)

#Calculation
Tc=T/math.sqrt(1-(Hc/H0));     #transition temperature(K)

#Result
print "transition temperature is",round(Tc,1),"K"

transition temperature is 11.3 K


## Example number 2, Page number 9-22¶

In [4]:
#importing modules
import math
from __future__ import division

#Variable declaration
e=1.6*10**-19;    #charge(c)
h=6.626*10**-34;  #plank constant
V=8.5*10**-6;     #voltage(V)

#Calculation
new=2*e*V/h;      #frequency(Hz)

#Result
print "frequency is",round(new/10**9,1),"*10**9 Hz"

frequency is 4.1 *10**9 Hz


## Example number 3, Page number 9-22¶

In [7]:
#importing modules
import math
from __future__ import division

#Variable declaration
T=2;         #temperature(K)
Tc=3.7;      #critical temperature(K)
H0=0.0306;   #critical magnetic field(A/m)

#Calculation
Hc=H0*(1-(T/Tc)**2);    #critical field(Tesla)

#Result
print "critical field is",round(Hc,5),"Tesla"

critical field is 0.02166 Tesla


## Example number 4, Page number 9-23¶

In [11]:
#importing modules
import math
from __future__ import division

#Variable declaration
Hc=200*10**3;    #critical magnetic field(A/m)
Tc=12;           #critical temperature(K)
H0=250*10**3;    #critical magnetic field(A/m)

#Calculation
T=Tc*math.sqrt(1-(Hc/H0)**2);     #maximum critical temperature(K)

#Result
print "maximum critical temperature is",T,"K"

maximum critical temperature is 7.2 K


## Example number 5, Page number 9-23¶

In [14]:
#importing modules
import math
from __future__ import division

#Variable declaration
T=2.5;         #temperature(K)
Tc=3.7;        #critical temperature(K)
H0=0.03;       #critical magnetic field(A/m)

#Calculation
Hc=H0*(1-(T/Tc)**2);    #critical field(Tesla)

#Result
print "critical field is",round(Hc,4),"Tesla"

critical field is 0.0163 Tesla


## Example number 6, Page number 9-23¶

In [16]:
#importing modules
import math
from __future__ import division

#Variable declaration
e=1.6*10**-19;    #charge(c)
h=6.625*10**-34;  #plank constant
V=650*10**-6;     #voltage(V)

#Calculation
new=2*e*V/h;      #frequency(Hz)

#Result
print "frequency is",round(new/10**9,2),"*10**9 Hz"

frequency is 313.96 *10**9 Hz


## Example number 7, Page number 9-24¶

In [18]:
#importing modules
import math
from __future__ import division

#Variable declaration
T=5;                    #temperature(K)
Tc=7.2;                 #critical temperature(K)
H0=6.5*10**3;           #critical magnetic field(A/m)

#Calculation
Hc=H0*(1-(T/Tc)**2);    #critical field(A/m)

#Result
print "critical field is",round(Hc/10**3,3),"*10**3 A/m"

critical field is 3.365 *10**3 A/m