Question

A tuning fork of frequency $384Hz$ gives $6$ beats in 2 seconds when sounded with another tuning fork B. What could be the frequency of B?

• A. $381Hz$
• B. $387Hz$
• C. It could be either A or B
• D. None of the above

Answer 1

Answer: (C)

It could be either A or B

Since $6$ beats are produced in $2$ seconds.
Thus beat frequency $b=\frac{6}{2}=3$ $Hz$
Beat frequency $b=|f_A-f_B|$
$\therefore$ $3=|384-f_B|$
Thus $f_B=384-3=381Hz$ or $f_B=384+3=387Hz$
Thus frequency of $B$ can either be $381Hz$ or $387Hz$.