Question

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

• A. $\frac{1}{4}$ sec
• B. $\frac{1}{8}$ sec
• C. $\frac{1}{6}$ sec
• D. $\frac{1}{12}$ sec

Answer 1

Answer: (B)

$\frac{1}{8}$ sec

Given $f_{beat}=4Hz$, we have to find the time interval between a maxima and minima.

We know that $T_{beat}=\frac{1}{f_{beat}}$

So,

$T_{beat}=\frac{1}{4}sec$

The time interval between one maxima and minima is $\frac{T_{beat}}{2}$

So $T_{req}=\frac{T_{beat}}{2}=\frac{1}{8}sec$

So, B is the correct answer.