In [4]:

```
#given
t=0.2 #Thickness of film in micro m
r=1.25 #Refractive index of liquid
w=(4000,5000) #Range of wavelength in Angstrom
q=35 #Angle observed in degrees
#Calculations
import math
u=math.asin(math.sin(q*3.14/180.0)/r)*180/3.14
w1=(2*t*10**-6*r*math.cos(u*3.14/180.0))/10**-10
w2=w1/2.0
#Output
print"Wavelength absent in reflected light is ",round(w2,0),"Angstrom"
```

In [1]:

```
#given
r=1.39 #Refractive index of the film
q=30 #Angle observed in degrees
w=(5125,5000) #Wavelengths of two consecutive dark bands in Angstrom
#Calculations
import math
r1=math.asin(math.sin(q*3.14/180.0)/r)*180/3.14
n=w[1]/(w[0]-w[1])
t=((n*w[0]*10**-8)/(2.0*r*math.cos(r1*3.14/180.0)))/10**-4
#Output
print"Thickness of the film is ",round(t,4),"*10**-4 cm"
```

In [10]:

```
#given
r=1.4 #Refractive index of the material
w=5893 #Wavelength of yellow light in Angstrom
n=10 #Number of bands
w1=0.009 #Width of band in m
#Calculations
import math
b=math.asin((w*10**-8)*180/3.14/(2.0*r*n*w1))
#Output
print"Angle of wedge is ",round(b,4),"degrees"
```

In [2]:

```
#given
r=1.0 #Refractive index
n=4 #Number of bands
w=6500 #Wavelength in Angstrom
#Calculations
t=(((n+(1/2.0))*w*10**-8)/(2*r))/10.0**-4
#Output
print"Thickness of wedge shaped air film is ",t,"*10**-4 cm"
```

In [11]:

```
#given
d=0.5 #Diameter of the ring in cm
n=4 #number of bands
w=5893 #Wavelength of light in Angstrom
q=30 #Angle at which light enters in degrees
#Calculations
import math
R=((d**2*math.cos(q*3.14/180.0))/(2.0*(2*n+1)*w*10**-8))
#Output
print"Radius of curvature of lens is ",round(R,1),"cm"
```