Question Detail
Question
One beam of coherent light travels path P₁ in arriving at point Q and another coherent beam travels path P₂ in arriving at the same point. If these two beams are to interfere destructively, the path difference |P₁ - P₂| must be equal to:
Correct Answer
Option A is the correct answer.
Detailed Explanation
For two coherent waves to interfere destructively at a point, their path difference must be an odd multiple of half-wavelengths. This means the path difference (Δx) should be:Δx = (m + 1/2)λ, where m = 0, 1, 2, ...This can also be written as Δx = (2m + 1)λ/2, which represents an odd number of half-wavelengths.
Hint
Recall the conditions for constructive and destructive interference in terms of path difference.