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)
- (A)6 s
- (B)4 s
- (C)1 s
- (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.
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