Which of the following is correct for the two coherent light waves to produce zero light?
The light waves should travel in perpendicular directions.
The light waves are in phase with each other
The light waves are out of phase with each other.
The light waves should pass through a prism.
the first one.
The correct answer is "The light waves are out of phase with each other."
To understand why this is the correct answer, let's break down the concept of coherent light waves and interference.
Coherent light waves are waves that have a constant phase relationship with each other, meaning they have the same frequency and their wave crests and troughs always align. When coherent light waves interact, interference occurs.
There are two types of interference: constructive and destructive. Constructive interference occurs when the crests of two waves align, resulting in reinforcement and the production of brighter light. Destructive interference occurs when the crests of one wave align with the troughs of the other wave, resulting in cancellation and the production of dimmer or zero light.
For two coherent light waves to produce zero light, these waves must be out of phase with each other. Out of phase means that the wave crests of one wave align with the troughs of the other wave, causing destructive interference and canceling out the light.
Therefore, the correct choice is "The light waves are out of phase with each other." The other options listed are incorrect because they do not describe the condition necessary for the two waves to cancel out and produce zero light.