Question

Three sound waves of equal amplitudes have frequencies $(f-1,f,f+1)$. They superpose to give beats. The number of beats produced per second is

• A. $2$
• B. $1$
• C. $4$
• D. $3$

Answer 1

The correct option is A

$2$

1. Beat produced between$(f-1)$ and$f$ is $1$.
2. Beat produced between $fandf+1is1$.
3. Beat produced between$(f-1)and(f+1)is2$.
4. Therefore, number of beats produced per second will be $2$.

Hence, the correct option is (A).