Interference Pattern Contrast – Rankers Physics

Young's Double Slit Experiment: Practice Problem & Solution

Assertion (A): The best contrast of the interference pattern is obtained when the intensity of the emerging lights from the two slits of the Young's experimental set-up are equal. Reason (R): Intensity is proportional to the square of the amplitude.
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Young's Double Slit Experiment. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true, as equal intensities (\(I_1 = I_2\)) ensure \(I_{text{min}} = 0\) for maximum contrast.

Reason (R) is true, as intensity \(I propto A^2\). However, (R) does not explain why \(I_1 = I_2\) leads to best contrast.

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