When a transparent medium of refractive index 1.5 and thickness of `2.5 xx 10^(-5)` m is introduced in front of a slit in Young's experiment, how much shift of interference fringes will occur ? `(d=0.4 mm and D=100 cm)`

Options

A. 5 cm
B. `2.5` cm
C. `0.25 cm`
D. `0.1 cm`

Answer

B

Explanation

Let displacement of interference fringe is `Deltax`
Now `(Deltaxd)/(D)=t(mu-1)` path difference)
`:. Deltax=(t(mu-1)D)/(d)`
`:. Deltax=(2.5xx10^(-5)(1.5-1.0)xx1)/(5xx10^(-4))`
`=2.5xx10^(-2)m-2.5` cm