Question

A prism is an optical medium bounded by three refracting plane surfaces. A ray of light suffers successive refractions on passing through its two surfaces and deviates by a certain angle from its original path. The refractive index of the material of the prism is given by `mu = sin((A + deltam)/2)//sin  A/2`. If the angle of incidence on the second surface is greater than an angle called critical angle, the ray will not be refracted from the second surface and is totally internally reflected.

The critical angle for a ray of light passing from glass to water is minimum for ______.

Options

• red colour

• blue colour

• yellow colour

• violet colour

Answer 1

The critical angle for a ray of light passing from glass to water is minimum for violet colour.

Explanation:

The critical angle is least for violet because its refractive index is the highest.