Question

Plane polarized light is passed through a polaroid. On viewing through the polaroid, it is found that when the polaroid is given one complete rotation about the direction of light,

• A. the intensity of light gradually decreases to zero and remains at zero.
• B. the intensity of light gradually increases to a maximum and remains maximum.
• C. there is no change in the intensity of light.
• D. the intensity of light varies such that it is twice maximum and twice zero.

Answer 1

The correct option is D the intensity of light varies such that it is twice maximum and twice zero.

The intensity of emergent light becomes maximum when the plane of vibration is parallel to pass axis of polaroid and the intensity becomes zero when plane of vibration is perpendicular to pass axis of polaroid.

During one complete rotation of polaroid, pass axis will be parallel to plane of vibration two times and perpendicular to plane of vibration two times. So the intensity of the emergent light varies such that it is twice maximum and twice zero.

Hence, $\left(D\right)$ is the correct answer.