A plane light wave with wavelength `lambda = 0.57mu m` falls normally on a suface on a surface
Channel: Doubtnut
Date: 30/08/2020

A plane light wave with wavelength `lambda = 0.57mu m` falls normally on a suface on a surface of a glass `(n = 1.60)` disc which shuts one and a half Fresnel zones for the observation point `P`. What must the minimum thickness of that disc be for the intensity of light at the point `P` to be the highest ? Take into account the interference of light on its passing through the disc.