# 9: Superconductivity¶

## Example number 9.1, Page number 9.22¶

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

#Variable declaration
T=8;    #temperature(K)
Hc=1*10**5;   #critical field(amp/m)
H0=2*10**5;   #critical field(amp/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 9.2, Page number 9.22¶

In [8]:
#importing modules
import math
from __future__ import division

#Variable declaration
h=6.626*10**-34;    #plancks constant
e=1.6*10**-19;
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 9.3, Page number 9.22¶

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

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

#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 9.4, Page number 9.23¶

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

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

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

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

temperature is 7.2 K


## Example number 9.5, Page number 9.23¶

In [19]:
#importing modules
import math
from __future__ import division

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

#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 9.6, Page number 9.23¶

In [22]:
#importing modules
import math
from __future__ import division

#Variable declaration
h=6.625*10**-34;    #plancks constant
e=1.6*10**-19;
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 9.7, Page number 9.24¶

In [26]:
#importing modules
import math
from __future__ import division

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

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

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

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