Question
Question: A narrow slit of width 2 nm is illuminated by monochromatic light of wavelength 500 nm. The distance...
A narrow slit of width 2 nm is illuminated by monochromatic light of wavelength 500 nm. The distance the first minima on either side on a screen at a distance of 1 m is :
A
5 nm
B
0.5 nm
C
1 nm
D
10 nm
Answer
0.5 nm
Explanation
Solution
: here a=2mm=2×10−3m
λ=500nm=500×10−9m=5×10−7m
D = 1m
The distance between the first minima on either side on a screen is
=a2λD=2×10−32×5×10−7×1
=5×10−4m=0.5×10−3m=0.5mm