A young's double slit apparatus is immersed in a liquid of refractive index 1.33.It has slit separation of 1 mm and interference pattern is observed on the screen at a distance 1.33 m from plane of slits.The wavelength in air is `6300 Å`
Calculate the fringe width.

Options

A. `6.3 xx 10^(-4) m`
B. `8.3 xx 10^(-4) m`
C. `6.3 xx 10^(-2) m`
D. `6.3 xx 10^(-5) m`

Answer

a

Explanation

The experimental set-up is in a liquid, therefore the wavelength of light will change
`lambda_("liquid") = (lambda_("air"))/(mu) = (6300)/(1.33) = (6300 xx 10^(-10))/(1.33) m`
Fringe width,
`beta = lambda_("liquid") D/(d) = (lambda_("air") D)/(mu d) = (6300 xx 10^(-10))/(1.33) xx (1.33)/(10^(-3))`
`= 6.3 xx 10^(-4) m`