# Chapter 10 Difraction¶

## Example 10.1 Page no 154¶

In [1]:
#given
D=1                                   #Distance of screen from the slit in m
w=6000                                #Wavelength in Angstrom
w1=0.6                                #Slit width in mm

#Calculations
x=((2*D*w*10**-10)/(w1*10**-3))*1000

#Output
print"Width of central band is ",x,"mm"

Width of central band is  2.0 mm


## Example 10.2 Page no 155¶

In [1]:
#given
d1=6000.0                             #Diffraction grating have number of lines per cm
q=50                                  #Diffracted second order spectral line observed in degrees
n=2                                   #Second order

#Calculations
import math
w=(math.sin(q*3.14/180.0)/(d1*n))*10**8

#Output
print"Wavelength of radiation is ",round(w,1),"Angstrom"

Wavelength of radiation is  6381.3 Angstrom


## Example 10.3 Page no 155¶

In [5]:
#given
d1=6000                      #Diffraction grating have number of lines per cm
w=6000                       #Wavelength in Angstrom

#Calculations
n=(1/(d1*w*10**-8))

#Output
print"Maximum order of diffraction that can be observed is ",round(n,2)

Maximum order of diffraction that can be observed is  2.78


## Example 10.4 Page no 155¶

In [7]:
#given
B=(3*3.14)/2                           #First secondary maxima at B

#Calculations
import math
I=(math.sin(B)/B)**2

#Output
print"Ratio of intensity of central maxima to first secondary maxima is ",round(I,3)

Ratio of intensity of central maxima to first secondary maxima is  0.045


## Example 10.5 Page no 155¶

In [8]:
#given
w=6400                                        #Wave length of light in Angstrom
w1=0.3                                        #Slit width in mm
d=110                                         #Distance of screen from the slit in cm
n=3                                           #order

#Calculations
x=((n*w*10**-10*(d/100.0))/(w1*10**-3))*1000

#Output
print"Distance between the centre of the central maximum and the third dark fringe is ",x,"mm"

Distance between the centre of the central maximum and the third dark fringe is  7.04 mm