Question

What is the difference between polarised light and unpolarised light?

Answer 1

Hint: Light is an electromagnetic wave made up of vibrating electric and magnetic fields. When the vibrations are in all the directions, the light is polarised light. When the vibrations are in a single direction, the light is called unpolarised light.

Complete answer:
Light, which helps us to see different objects, is a part of a large spectrum of electromagnetic waves. These electromagnetic waves are emitted by the sun.
Let us discuss electromagnetic waves and later see what is polarised light and unpolarised light.
Electromagnetic waves are formed when a charged particle (particle) vibrates or accelerates in all the directions. When the electron vibrates, it creates vibrating electric fields and vibrating magnetic fields in all the directions. An electromagnetic wave is a transverse wave. This means that the vibrations of the electric fields and the magnetic fields are perpendicular to the propagation of the wave.
The normal or ordinary light such as the light emitted by a lamp, has the multiple planes of vibrations. The light having more than one plane of vibrations is called unpolarised light.
If the vibrations of the electric field of the light are in a single plane then the light is called polarised light.
It is possible to convert the unpolarised light into a polarised light. This can be done with the help of a device called polariser. A polariser has a single axis of transmission. Therefore, when an unpolarised light passes through a polariser, the plane of vibrations that is parallel to the axis of transmission of the polariser is allowed to pass to the other side. Hence, the coming light has only one plane of vibrations. Thus, the light is polarised.

Note: When the unpolarised light passes through a polariser and comes out as polarised light, the intensity of the light becomes half of the initial intensity of the unpolarised light.
When an unpolarised light passes through a polariser, it actually absorbs all the oscillations except the oscillations that are parallel to the axis transmission. This is the property of the material of the polariser.