## Calculate intrinsic carrier density
import math
rho = 3000. ## resistivity in ohm m
mu_e = 0.14
mu_h = 0.05
e = 1.602e-19 ## charge on electron
print("\n Example 15.1")
sigma = 1./rho
n = sigma/((mu_e+mu_h)*e)
print'%s %.2e %s '%("\n Intrinsic carrier density is",n," m^-3")