In [1]:

```
from __future__ import division
import math
# Python Code Ex15.1 Determining Photon number by
#using Planck quantum law: Page-486 (2010)
#Variable declaration
h = 6.626e-034; # Planck's constant, Js
f = 1760e+03; # Frequency of the radio transmitter, Hz
P = 10e+03; # Power of radio transmitter, W
#Calculation
E = h*f; # Energy carried by one photon from Planck's law, J
N = P/E; # Number of photons emitted per second, number per second
#Result
print"\nThe number of photons emitted per second ="
print round( (N*10**-30),2)*10**30
```

In [2]:

```
from __future__ import division
import math
# Python Code Ex15.2 Finding suitable energy for
# Photoelectric Effect from Na metal: Page-486 (2010)
#Variable declaration
e = 1.602e-019; # Charge on an electron, C
h = 6.626e-034; # Planck's constant, Js
c = 3.0e+08; # Speed of light in vacuum, m/s
lamb = 2800e-010; # Wavelength of incident light, m
#Calculation
W = 2.3*e; # Work function of Na metal, J
f = c/lamb; # Frequency of the incident light, Hz
E = h*f; # Energy carried by one photon from Planck's law, J
#Result
print"\nThe energy carried by each photon of radiation =",round(E/e,2)," eV"
if (E > W):
print"\nThe photoelectric effect is possible.."
else:
print"\nThe photoelectric effect is impossible.."
```

In [3]:

```
from __future__ import division
import math
# Python Code Ex15.3 Finding number of photons for
# green wavelength of Hg: Page-487 (2010)
#Variable declaration
h = 6.626e-034; # Planck's constant, Js
c = 3.0e+08; # Speed of light in vacuum, m/s
lamb = 496.1e-09; # Wavelength of green light of mercury, m
E_total = 1; # Work done by photons from green light, J
#Calculation
f = c/lamb; # Frequency of the green light, Hz
E = h*f; # Energy carried by one photon from Planck's law, J
N = E_total/E; # Number of photons of green light of Hg
#Result
print"\nThe number of photons of green light of Hg ="
print round( (N*10**-18),2)*10**18
```

In [4]:

```
from __future__ import division
import math
# Python Code Ex15.4 Photoelectric effect in a photocell: Page-487 (2010)
#Variable declaration
e = 1.602e-019; # Charge on an electron, C
h = 6.626e-034; # Planck's constant, Js
c = 3.0e+08; # Speed of light in vacuum, m/s
lamb = 1849e-010; # Wavelength of incident light, m
V_0 = 2.72; # Stopping potential for emitted electrons, V
#Calculation
f = c/lamb; # Frequency of incident radiation , Hz
E = h*f; # Energy carried by one photon from Planck's law, J
T_max = e*V_0; # Maximum kinetic energy of electrons, J
# We have, T_max = E - h*f_0 = h*f - W
f_0 = (-T_max + E )/h # Threshold frequency for Cu metal, Hz
W = h*f_0/e; # Work function of Cu metal, eV
#Result
print"\nThrehold frequency for Cu metal =",round((f_0*10**-14),2)*10**14," Hz"
print"\nThe work function of Cu metal = ",round(W)," eV"
print"\nThe maximum kinetic energy of photoelectrons =",round(T_max/e,2)," eV"
```

In [5]:

```
from __future__ import division
import math
# Python Code Ex15.5 Energy required to stimulate the emission of
# Na d-lines: Page-497 (2010)
#Variable declaration
e = 1.6e-019; # Charge on an electron, C
h = 6.626e-034; # Planck's constant, Js
c = 3.0e+08; # Speed of light in vacuum, m/s
lambda_mean = 5893e-010; # Wavelength of incident light, m
#Calculation
# The energy of the electron which must be transferred to the atoms of Na
delta_E = h*c/(lambda_mean*e);
#Result
print"\nThe energy which must be transferred to stimulate"
print" the emission of Na d-lines = ",round(delta_E,2)," eV"
```