JEE Main 2020 — Wave Optics Question with Solution
From: JEE Main 2020 (Online) 5th September Evening Slot
Question
Two coherent sources of sound, S1 and S2,
produce sound waves of the same wavelength,
= 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 :
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 :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: C
Correct answer
C3 m
Step-by-step explanation
Initially S2L = 2 m
S1L = = 2.5 m
For minimum at (L)
S1L – S2L = x =
2.5 - 2 =
0.5 =
1 = 2n + 1
n = 0 (first minima)
so at P first maxima
S1P – S2P = n = 1
d - 2 = 1
d = 3 m
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