In the Young's double slit experiment , a mica slip of thickness t and refractive index `mu` is introduced in the ray from first source `S_(1)` . By how much distance fringes pattern will be displaced ? (d = distance between the slits and D is the distance between slits andscreen)

Options

A. `(d)/(D)(mu-1)t`
B. `(D)/(d)(mu-1)t`
C. `(d)/((mu-1)D)`
D. `(D)/(d)(mu-1)`

Answer

B

Explanation

For a path difference `(mu - 1)t`, the shift is
`x = (mu -1)t (D)/(d)`