JEE Main 2024 Physics question
In Young's double slit experiment, light from two identical sources are superimposing on a screen. The path difference between the two lights reaching at a point on the screen is 7λ/4. The ratio of intensity of fringe at this point with respect to the maximum intensity of the fringe is :
Answer: (D)
Solution
I = I₀cos²(Δφ/2). Δφ = (2π/λ)(7λ/4) = 7π/2 ≡ 3π/2, so I/I₀ = cos²(3π/4) = 1/2.