Question

What does polarisation of light prove?
(A) Corpuscular nature of light
(B) Longitudinal nature of light
(C) Quantum nature of light
(D) Transverse nature of light

Answer 1

Polarisation is defined as the mechanism of converting unpolarised light into polarised light. Polarised waves are light waves where the vibrations of waves propagate in one plane.

Complete step by step answer:
In physics, Polarisation is characterised as a phenomenon induced by the wave propagation of electromagnetic radiation. Light is an electromagnetic wave and we know that electromagnetic waves are of two types –transverse and longitudinal. Transverse waves are waves whose displacement of the objects in the waves is perpendicular to the wave’s direction of motion. Polarisation is the only process which indicates that light is a transverse wave. Polarisation is the feature of wave oscillations having a definite direction proportional to the wave’s propagation route. The direction of polarisation is considered to be the direction parallel to the electric field of the EM wave.
As light is passed through a polarising screen, the oscillations would be reflected in all directions except one. The electric/magnetic vector of light originating from the sheet oscillates in one direction and is claimed to be plane polarised.
Option A cannot be correct because the corpuscular nature of light states that light particles are made up of little particles called corpuscles. It does not explain the propagation of light.
Option B is correct because light waves are not longitudinal. Only sound is longitudinal in nature.
Option C is also not correct because the quantum nature of light explains the composition of light. It tells us that all light and matter are tiny particles that have wave-like properties associated with them.
Hence,option D is correct because polarisation of light proves transverse nature of light.

Note: It is easy to get confused between transverse and longitudinal propagation because both are types of electromagnetic propagation only and we know that light travels through electromagnetic propagation but polarisation requires wave direction to be perpendicular to propagation direction and only light can do this.