Question

Out of the given four waves (1), (2), (3) and (4)

$y=asin(kx+\omega t)$ ...................(1)

$y=asin(\omega t-kx)$ ...................(2)

$y=acos(kx+\omega t)$ ...................(3)

$y=asin(\omega t-kx)$ ...................(4)

emitted by four different sources $S_1,S_2,S_{3}and{S}_4$ respectively, interference phenomena would be observed in space under appropriate conditions when

• A. Source S₁ emits wave (1) and S₂ emits wave (2)
• B. Source S₃ emits wave (3) and S₄ emits wave (4)
• C. Source S₂ emits wave (2) and S₄ emits wave (4)
• D. S₄ emits waves (4) and S₃ emits waves (3)

Answer 1

The correct option is C

Source S₂ emits wave (2) and S₄ emits wave (4)

For interference, two waves must have a constant phase relation ship.

Equation '1' and '3' and '2' and '4' have a constant phase relationship of $\frac{\pi }{2}$ out of two choices. Only one $S_2$ emitting '2' and $S_4$ emitting '4' is given so only (c) option is correct.