Two coherent sources of sound, S1 and S2, produce sound waves of the… | JEE Main 2020 (5 Sep, Shift 2)

Q18JEE Main 2020 · 5 SEP · SHIFT 2Difficult

Reflection, Superposition & Interference

Two coherent sources of sound, S1 and S2, produce sound waves of the same wavelength, $\lambda$ = 1 m, in phase. S1 and S2 are placed 1.5 m apart (see fig). A listener, located at L, directly in front of S2 finds that the intensity is at a minimum

when he is 2 m away from S2. The listener moves away from S1, keeping his distance from S2 fixed. The adjacent maximum of intensity is observed when the listener is at a distance d from S1. Then, d is:

Show answer and solution

Answer: (c)

At $L$ : $S_1L = \sqrt{1.5^2 + 2^2} = 2.5\text{ m}$ , path difference $= 2.5 - 2 = 0.5\text{ m} = \frac{\lambda}{2}$ (minimum).
Moving away from $S_1$ increases the path difference; the next maximum needs path difference $= \lambda = 1\text{ m}$ .
$d - 2 = 1 \Rightarrow d = 3\text{ m}$ .
So the answer is (c) $3\text{ m}$ .

Report a mistake

Reflection, Superposition & Interference question from JEE Main 2020 (5 Sep, Shift 2)

More questions on Reflection, Superposition & Interference