In [2]:

```
# Given
a = 3e-10 # side of square lattice in m
h = 6.62e-34 # Planck constant in J sec
e = 1.6e-19 # charge on an electron in C
m = 9.1e-31 # mass of electron in kg
#Calculations
p = (h / (2 * a))
E = (p**2 / (2 * m)) * (1. / e)
#Result
print "Electron momentum value at the sides of first Brilloin zone is %.1e kg-m/sec\nEnergy of free electron is %.1f eV"%(p,E)
```

In [3]:

```
from math import log,pi
# Given
n = 5e22 # no. of atoms per m^3
t = 300 # room temperature in K
k = 1.37e-23 # Boltzmann's constant in J/K
h = 6.62e-34 # Planck constant in J sec
e = 1.6e-19 # charge on an electron in C
m = 9.1e-31 # mass of electron in kg
#Calculations
d = (k * t) * log(n * h**3 / (2 * (2 * pi * m * k * t)**(3./2)))
#Result
print "Position of fermi level is %.3f eV"%(-d/e)
#Answer varies due to round-off errors
```

In [4]:

```
# Given
E = 0.3 # Fermi energy in eV
T = 330 # temperature in K
t = 300 # room temperature in K
k = 1.37e-23 # Boltzmann's constant in J/K
h = 6.62e-34 # Planck constant in J sec
e = 1.6e-19 # charge on an electron in C
m = 9.1e-31 # mass of electron in kg
#Calculations
d = (T / t) * (E)
print "New position of fermi level is %.2f eV"%d
```

In [5]:

```
from math import *
# Given
E = 0.7 # band gap for semiconductor in eV
t = 300 # room temperature in K
k = 1.38e-23 # Boltzmann's constant in J/K
h = 6.62e-34 # Planck constant in J sec
e = 1.6e-19 # charge on an electron in C
m = 9.1e-31 # mass of electron in kg
#Calculations
n = 2 * ((2 * pi * k * t * m) / h**2)**(3./2) * exp(-(E * e / (2 * k * t)))
#Result
print "Density of holes and electron is %.1e per m^3"%n
```

In [6]:

```
# Given
n = 5e28 # no. of atoms in per m^3
e = 1.6e-19 # charge on an electron in C
#Calculations
R = -(1 / (n * e))
#Resilt
print "Hall coefficient is %.3e m^3/C"%R
```

In [7]:

```
# Given
a = 4.28e-10 # cell side of Na in m
e = 1.6e-19 # charge on an electron in C
#Calculations
n = (2 / a**3)
R = -(1 / (n * e))
#Result
print "Hall coefficient is %.3e m^3/C"%R
```