Question

When a ray of light travelling in air enters obliquely into a glass slab, it is observed that the light ray emerges parallel to the incident ray but it is shifted sideways slightly. Draw a labelled ray diagram to illustrate it.

Answer 1

The emergent light beam is parallel to the incident light beam but slightly displaced to the side when it passes through a glass slab. In this instance, refraction occurs twice: first when the light enters the glass slab from the air and again when it leaves the glass slab and enters the air.

Refraction of light through a rectangular glass slab