The frequency of tuning fork $A$ is $256\,Hz$. It produces $4\,beats/sec$ with tuning fork $B$. When wax is applied to tuning fork $B$,$6\,beats/sec$ are heard. By reducing a small amount of wax,$4\,beats/sec$ are heard. The frequency of $B$ is .... $Hz$.

$A$ string under a tension of $129.6 \ N$ produces $10 \ beats/s$ when it is vibrated along with a tuning fork. When the tension in the string is increased to $160 \ N$,it sounds in unison with the same tuning fork. Calculate the fundamental frequency of the tuning fork in $Hz$.

Two sitar strings $A$ and $B$ playing the note $Sa$ are slightly out of tune and produce beats of frequency $5 \ Hz$. The tension of the string $B$ is slightly decreased and the beat frequency is found to decrease to $3 \ Hz$. What is the original frequency of $B$,if the frequency of $A$ is $255 \ Hz$?

Three sound waves of equal amplitudes have frequencies $(n - 1)$,$n$,and $(n + 1)$. They superimpose to produce beats. The number of beats produced per second is:

Two tuning forks $A$ and $B$ produce notes of frequencies $258 \,Hz$ and $262 \,Hz$. An unknown note sounded with $A$ produces certain beats. When the same note is sounded with $B$, the beat frequency gets doubled. The unknown frequency is (in $\,Hz$)

The number of beats produced per second by two vibrations: $x_1 = x_0 \sin(646\pi t)$ and $x_2 = x_0 \sin(652\pi t)$ is