JEE Main · 2025 · 07 Apr 2025 · Shift 1 · Waves & Sound

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Two harmonic waves moving in the same direction superimpose to form a wave where is in seconds. Find the period with which they beat (close to nearest integer)
  1. (A)6 s
  2. (B)4 s
  3. (C)1 s
  4. (D)2 s✓ Correct

Answer: (D)

Solution

The product form is rewritten as a sum of two cosines:

The two superposing waves have angular frequencies and rad/s, so the beat angular frequency is their difference, rad/s. The beat period is

To the nearest integer the beat period is s.

JEE Main · 2025 · 07 Apr 2025 · Shift 1 · Single correct option

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