Class 12th Physics 2017 Set3 Delhi Board Paper Solution
Distinguish between unpolarised light and linearly polarised light. How does one get linearly polarised light with the help of a polaroid?
Unpolarised light: A light wave in which electric vector oscillates in all possible directions in a plane perpandicular to the direction of propagation is called unpolarised light as shown in the below image:
Linearly polarised: if the electric vector's vibration is restricted to one direction only in a plane perpandicular to the direction of propagation. the light is called linearly polarised.
As shown in the below image:
Polaroid is a special crystalline solid which contains a special axis called optic axis. When we make a unpolarised light to fall on a polaroid, only vibration parallel to optic axis is allowed to pass through and all other vibration are cut. Thus, the output is a plane polarised light.As shown in the below image:
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