In a Young's double-slit experiment, the phase differences at points P and Q are π/3 and π/2 respectively. The two interfering waves have equal amplitude. The ratio I(P): I(Q) is:
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Question

In a Young's double-slit experiment, the phase differences at points P and Q are π/3 and π/2 respectively. The two interfering waves have equal amplitude. The ratio I(P):I(Q) is:

G1 Physics · Accepted Answer

For equal slit intensities I₀, I = 4I₀ cos²(φ/2) At P, φ = π/3: I(P) = 4I₀ cos²(π/6) = 4I₀(3/4) = 3I₀ At Q, φ = π/2: I(Q) = 4I₀ cos²(π/4) = 4I₀(1/2) = 2I₀ Therefore, I(P):I(Q) = 3:2 Hence option A follows.