Q.

As shown in the figure, in Young's double slit experiment, a thin plate of thickness t=10μm and refractive index μ=1.2 is inserted infront of slit S1. The experiment is conducted in air (μ=1) and uses a monochromatic light of wavelength λ=500nm. Due to the insertion of the plate, central maxima is shifted by a distance of xβ0. β0 is the fringe-width before the insertion of the plate. The value of the x is ________ .                     [2023]


Ans.

(4)

Fringe shift S=t(μ-1)λβ0

                          =10×10-6(1.2-1)5×10-7β0=xβ0

 x=10-5×0.25×10-7=4