Question

The lateral shift in rectangular glass slab depends on which of the following properties of a medium?

A. Refractive Index

B. Thickness

C. Color

D. Both A and B

Answer 1

Use the formula for lateral shift of a light ray passing through a rectangular glass slab i.e, $\Delta x=\frac{t\sin (i-r)}{\cos r}$ where, $\Delta x$ is the lateral shift, $t$ is the thickness of the glass slab, $i$ is the angle of incidence and $r$ is the angle of refraction

Complete solution:

A light ray entering a glass slab gets refracted and moves towards the normal at the interface as glass is denser than air. It travels through the thickness of the glass slab and again moves away from the normal when exiting the glass slab at the interface. The emergent ray is parallel to the incident ray but laterally displaced.

The perpendicular distance between the incident and the emergent ray is known as the lateral shift. It depends on the thickness of the glass slab, angle of incidence and angle of refraction as given by the formula. The angle of refraction and angle of incidence are related with the refractive index in accordance with Snell’s law. Hence, the lateral shift also depends on the refractive index.

Therefore, the correct answer is option D.

Note: If the light ray is incident normally, then it does not experience any lateral shift. The angle of incidence is equal to the angle of emergence.