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.
I would think that the answer would be C (the light waves are out of phase with each other), but I feel like that may be one of those trick-questions.
The light waves are out of phase with each other.
Thank you!
You are correct, the answer is C: "The light waves are out of phase with each other." When two waves are completely out of phase, meaning their peaks and troughs align with each other, they can interfere destructively and cancel each other out, resulting in zero light. This is known as destructive interference. Therefore, option C is the correct choice in this case.
You are correct that option C, "The light waves are out of phase with each other," is the correct answer. When two coherent light waves interfere with each other, the resulting light intensity depends on the phase difference between the waves.
To understand why this is the case, let's discuss interference. Interference occurs when two or more waves overlap in space and time. In the case of light waves, this overlap can result in the reinforcement or cancellation of the waves, leading to changes in light intensity.
When two coherent light waves are in phase with each other, their peaks and troughs align perfectly. This alignment leads to constructive interference, where the waves reinforce each other and the light intensity becomes brighter.
On the other hand, when the light waves are out of phase with each other, their peaks and troughs do not align. This misalignment leads to destructive interference, where the waves cancel each other and the light intensity becomes darker or even zero.
Passing the light waves through a prism, as mentioned in option D, does not affect their phase relationship or interference pattern. A prism only refracts light and separates it into its constituent colors based on their different wavelengths.
To summarize, for two coherent light waves to produce zero light, they should be out of phase with each other. The perpendicular directions mentioned in option A do not affect their phase but rather refer to the polarization of the waves. The statement in option B, that the light waves are in phase with each other, would lead to constructive interference and not zero light.