# Critical field
import math
#variable declaration
h0=0.0306 # critical field
t1=2.0 # Temperature
t2=3.7 # Temperature corresponds to h0
#calculation
he=h0*(1-((t1**2)/t2**2))
#Result
print("The critical field at %d K is %.5f T"%(t1,he))
# Critical current for a wire
import math
#variable declaration
t1=4.2 # Temperature
t2=7.18 # critical Temperature
h0=6.5*10**4 # critical magnetic field
#calculations
he=h0*(1-((t1**2)/t2**2))
r=0.5*10**-3
I=2*3.14*he*r
#Result
print("The critical current through a wire of lead is %.2f A"%I)
#critical temperature
import math
#variable declaration
tc1=4.185 # Critical temperature of lead
m1=199.5 # isotopic mass 1
m2=203.4 # isotopic mass 2
#calculation
tc2=tc1* math.sqrt(m1/m2)
#Result
print("The critical temperature for metal with isotopic mass of %.1f is %.3f K"%(m2,tc2))