In Young’s double-slit experiment, the intensity of light at a point on the screen where path difference is λ is K. The intensity at a point where path difference is λ/4 will be:
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In Young’s double-slit experiment, the intensity of light at a point on the screen where path difference is λ is K. The intensity at a point where path difference is λ/4 will be:

G1 Physics · Accepted Answer

Step 1: At Δx = λ, phase Δφ = 2π and the point is maximum, so Iₘₐₓ = K. Step 2: At Δx = λ/4, phase Δφ = π/2. Step 3: I = Iₘₐₓ cos²(Δφ/2) = K cos²(π/4) = K/2. Final answer: (C) K/2.