In Young's double slit experiment, the sepcaration between the slits is halved and the distance between the slits and the screen is doubled. The fringe width is

Options

A. will not change
B. will become half
C. will be doubled
D. will become four times

Answer

D

Explanation

`beta=(Dlambda)/d, beta^(')=2(Dlambda)/(d//2)=(4Dlambda)/d`
`beta^(')/beta=4implies beta^(')=4beta`