In double slite experiment if the transparent material of refractive index `mu` s introduced in between second slit and screen, the fringe widht on the screen moves

Options

A. vertically downwards slightly
B. vertically upwards slightly
C. horizontally towards left
D. horizontally towards right

Answer

A

Explanation

If the transparent sheet of thickness 't' and refractive index `mu` is introduced slite and screen then fringe pattner is displaced through a distance of `(beta//lambda) (mu-1)` towards the side on which the sheet is placed and there is no other change in the pattern.
In the given atom sheet is placed betwen second slite and screen hance fringe pattern will be moved vertically downwards.