There is layer of medium of variable refractive index `mu = sqrt(2) - (1)/(sqrt(2)) y` (where `0 le t lt 1//2`) sandwitched between the layer of glass and air A beam of light travelling in air at an angle `45^(@)` has a width `Delta omega`. When the beam enters the layer of glass its width becomes : `(mu_("glass") = sqrt(2))`

Options

A. `sqrt((3)/(2)) Delta omega`
B. `sqrt((2)/(3)) Delta omega`
C. `sqrt((1)/(3)) Delta omega`
D. `Delta omega`

Answer

A

Explanation

`(Delta omega)/(Delta omega),(cos theta_("air"))/(cos theta_("glass"))` putting the values we have `Delta omega' = sqrt((3)/(2)) Delta omega`.