A parallel beam of light is incident from air at an angle `alpha` on the side PQ of a right angled
Channel: Doubtnut
Date: 2020-07-12

A parallel beam of light is incident from air at an angle `alpha` on the side PQ of a right angled triangular prism of refractive index `n=sqrt2. Light undergoes total internal reflection in the prism at the face PR when `alpha` has a minimum value of `45degree`.  The angle `theta` of the prism is `