A double slit apparatus is immersed in a liquid of refractive index 1.33. it has slit separation of 1 mm and distance between the plane of the slits and the screen is 1.33 m. the slits are illuminated by a parallel beam of light whose wavelength in air is 6300 Å. what is the fringe width?

Options

A. `(1.33xx0.63)mm`
B. `(0.63)/(1.33)mm`
C. `(0.63)/((1.33)^(2))mm`
D. `0.63mm`

Answer

D

Explanation

In air, `X_(a)=(lamdaD)/(d)` and in the liquid, the fringe width is given by
`X_(L)=(X_(a))/(n_(L))=(lamdaD)/(d*n_(L))`
`=(6300xx10^(-10)xx1.33)/(10^(-3)xx1.33)`
`=63xx10^(-5)m=0.63xx10^(-3)m=0.63mm`