Question

If the equations of two sound waves are $y_1=5\sin 252\pi t$ and $y_2=5\sin 281\pi t$ respectively. Then the number of beats heard per second will be

• A. beats will not be heard
• B. $6$
• C. $12$
• D. $34$

Answer 1

The correct option is A beats will not be heard

frequency of both waves are

$f_1=\frac{252\pi }{2\pi }$

$f_2=\frac{281\pi }{2\pi }$

no of beats $n=f_2-f_1=140.5-126=14.5hz$

no beats will be heard as the human ear is capable of detecting beats of only 7 Hz or less.