In Young's experiment , the fringe width of the fringes with light of wavelength 6000 Å is `2.0` mm . What will be the fringe width if the entire apparatus is immersed in a liquid of refractive index `1.33` ?

Options

A. 5mm
B. 3mm
C. `1.5 mm`
D. 1mm

Answer

C

Explanation

`beta = (lambda D)/(d), beta. = (lambda.D)/(d)`
`therefore (beta.)/(beta) = (lambda.D)/(d) xx (d)/(lambda D) = (lambda.)/(lambda) = (1)/(mu)`
`beta. = (beta)/(mu) = (2)/(1.33) = 1.5` mm