COMEDK 2024 Shift 2 Paper

Young's double slit experiment involves the interference of light waves originating from two slits which produce a pattern of bright and dark fringes due to constructive and destructive interference respectively. In this problem, we introduce a glass plate in the path of one of the beams, which causes an additional path difference due to the change in the optical path length.
Given:
Wavelength of light, λ=500‌nm=500×10−9m
Refractive index of the glass plate, n=1.5
Thickness of the glass plate, t=0.1‌mm=0.1×10−3m
The optical path difference introduced by the glass plate is given by:
∆d=(n−1)t
Substituting the given values:
The shift in the number of fringes due to this path difference is given by:
Number of fringes =‌

∆d

λ

Substituting the values for ∆d and λ :
Number of fringes Thus, the number of fringes that will shift due to the introduction of the glass plate is 100 .
The correct option is A. 100