Question

Two tuning forks have frequencies $380Hz$ and $384Hz$ respectively$.$ when they are sounded together$,$ they produce $4$ beats$.$ After hearing the maximum sound$,$ how long will take to hear the minimum sound

• A. 1/4 sec
• B. 1/8 sec
• C. 1 sec
• D. 2 sec

Answer 1

The correct option is B 1/8 sec

Beat period $T=\frac{1}{n_1-n_2}=\frac{1}{384-380}=\frac{1}{4}\sec$

hence minimum time interval between maxima and minima $t=\frac{T}{2}=\frac{\frac{1}{4}}{2}=\frac{1}{8}\sec$

Hence,

option $\left(B\right)$ is correct answer.