2 loudspeakers are emitting sound waves of wavelength λ with an initial phase difference of π 2 . At what minimum distance from O on line AB will one hear maxima?

Step-by-step solution

Δ ϕ = 2 n π ⇒ π 2 + 2 π λ d sin ⁡ θ = 2 n π 2 π λ   d sin ⁡ θ = 2 n - 1 2 π s i n θ =   2 n - 1 2 λ 2 d = 1 2 × λ 2 × 3 λ = 1 12 ⇒ y 100 λ 2 = 1 12 144 y 2 = 100 λ 2 y ≈ 100 λ 12 = 25 λ 3