Question

Which amongst the four waves shown cannot be polarized?
$\left( A \right)$ Light waves
$\left( B \right)$ Sound waves
$\left( C \right)$ Infrared waves
$\left( D \right)$ X rays

Answer 1

- Hint: In this question use the property that all transverse waves can be polarized as the direction of the oscillation in the polarized wave is perpendicular to the direction of the wave's motion, so use this concept to solve the question.

Complete step-by-step solution -

An electromagnetic wave such as light consists of a combined electric oscillating field and magnetic field that are both perpendicular to each other.
Through definition, electromagnetic wave "polarization" refers to the direction of the electric field.
The fields oscillate in one direction, in linear polarization.
In circular or elliptical polarization the fields rotate in a plane as the wave travels at a constant rate.
Rotation can be in two directions,
If the fields rotate in the right direction of wave travel, the right circular polarization is called
Although this is called left circular polarization if the fields rotate in a left-hand direction.
Now as we all know all transverse waves can be polarized.
And one of the very best examples of transverse waves is electromagnetic waves.
Electromagnetic waves include:
Light waves, radio waves, X rays, infrared waves etc.
So all these waves can be polarized.
But sound waves cannot be electromagnetic waves.
So it cannot be polarized.
So this is the required answer.
Hence option (B) is the correct answer.

Note – There are two groups of transverse waves first, and one longitudinal waves second. A good example of longitudinal waves is the sound wave moving through the air. Sound waves are longitudinal, meaning they oscillate parallel to their movement direction. Because there is no part of the oscillation of a sound wave that is perpendicular to its motion, it cannot polarize sound waves.