In Young's double experiment, slits are kept 0.4 mm apart from each other and the screen is placed at 2 m from the slit. The fringe width for a given monochromatic source of light is 0.8 mm. if the whole set up is kept in a medium of R.I. 1.6 , the fringe width will be

Options

A. 0.3 mm
B. 0.4 mm
C. 0.2 mm
D. 0.5 mm

Answer

D

Explanation

`X=(lamdaD)/(d)` or `Xproplamda`
In a denser medium, both `lamda and X` are decreased and `X'=(X)/(n)`
`therefore X'=(X)/(n) =(0.8)/(1.6)=0.5` mm