Question

Assertion : Beats can also be observed by two light sourcesas in sound.
Reason : Light sources have constant phase deference.
A. If both assertion and reason are true and reason is the correct expleanation of assertion.
B. If both assertion and reason are true and reason is not the correct expleanation of assertion.
C. If assertion is true but reason is false.
D. If assertion and reason both are false.

Answer 1

Correct Answer - D
As emission of light from atom is a random and rapid phenomenon. The phase at a point due to two independent light source will change rapidly and randomly.Therefore, instead of beats, we shall get uniform intensity. However if light sources are LASER beams of nearly equal frequencies, it may possible to observe the phenomenon of beats in light.