How will the emergent ray be after refraction of light through a glass slab?

Question

Question

This question was previously asked in

RRB JE CBT I - (Held On: 30 May 2019 Shift 1)

The emergent ray and the incident rays are random
The emergent ray is at 90 degrees to the incident ray
The incident ray goes without deflection and emergent ray is same as incident ray
The emergent ray is parallel to the incident ray

Answer 1

The correct answer is The emergent ray is parallel to the incident ray

Key Points

The emergent ray is parallel to the incident ray after refraction through a glass slab.
This happens because the light ray refracts twice: once when entering the glass slab and once when exiting it, resulting in an overall parallel shift.
Refraction at the two surfaces of the glass slab causes the light to bend towards and then away from the normal, making the emergent ray parallel to the incident ray but displaced laterally.
The lateral displacement depends on the thickness of the glass slab and the angle of incidence.

Additional Information

Refraction is the bending of light as it passes from one medium to another with different optical densities.
The Law of Refraction, or Snell's Law, states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for a given pair of media.
When light enters a denser medium (e.g., air to glass), it bends towards the normal, and when it exits to a less dense medium (e.g., glass to air), it bends away from the normal.
The emergent ray being parallel to the incident ray is a characteristic property of light passing through a rectangular glass slab.