AIIMS 2017 Physics Interference MCQ Question

In Young’s double slit experiment, the contrast between the maximum and minimum intensities is maximized when one of the intensities is zero (option C), leading to a clear distinction between bright and dark fringes. This occurs because if either beam is absent, the interference pattern is solely determined by the remaining beam, enhancing visibility. Option A (|I₁ − I₂| is large) can lead to a noticeable difference, but not necessarily a good contrast if both intensities are still significant. Option B (|I₁ − I₂| is small) results in a nearly uniform intensity, diminishing the visibility of the interference pattern. Option D (I₁ = I₂) produces a maximum intensity but does not enhance contrast as effectively as having one intensity at zero.