In a Young's double-slit experment, the fringe width is `beta`. If the entire arrangement is now placed inside a liquid of refractive index `mu`, the fringe width will become

Options

A. `beta/(n+1)`
B. `n beta`
C. `beta/n`
D. `beta/(n-1)`

Answer

C

Explanation

We have
`beta=(lambdaD)/d`
because The arrangement is placed in a liquid of refractive index n
`:.lambda=lambda/n`
Therefore fringe width
`beta'=(lambdaD)/(dn)`
or `beta'=beta/n`