Embibe Experts Solutions for Chapter: Refraction of Light, Exercise 1: West Bengal Board-2018

Explain total internal reflection from the laws of refraction.

A ray of light is incident at a small angle $\theta$ on a rectangular glass slab of thickness $\text{t}$. If the refractive index of the glass slab is $\mu$, show that the perpendicular distance between the emergent ray from the slab and the incident ray is $\frac{\mathrm{t\theta }(\mathrm{\mu }-1)}{\mathrm{\mu }}$.

In case of refraction write down the relation between critical angle and the refractive index of denser medium.

For minimum deviation ${\mathrm{\delta }}_{\mathrm{m}}$, assuming that the angle of incident= angle of emergence , show that the refractive index of the material of the prism is ,

$\mathrm{\mu }=\frac{\sin \left\{{\displaystyle \frac{{\mathrm{\delta }}_{\mathrm{m}}+\mathrm{A}}{2}}\right\}}{\sin \left({\displaystyle \frac{\mathrm{A}}{2}}\right)}$, where $\mathrm{A}$ is the refractive angle of the prism.