The convex surface of a plano-convex glass lens comes into contact with a glass plate. The curvature
Channel: Doubtnut
Date: 16/08/2020

The convex surface of a plano-convex glass lens comes into contact with a glass plate. The curvature radius of the lens's convex surface is `R`, the wavelength o flight is equal to `lambda`. Find the width `Delta r` of a Newton ring as a function of its radius `r` in the region where `Delta r lt lt r`.