Two identical wires are vibrating in unison. If the tension in one of the wires is increased by $2 \%$,five beats are produced per second by the two vibrating wires. The initial frequency of each wire is $(\sqrt{1.02} \approx 1.01)$. (in $Hz$)

Two tuning forks have frequencies $256 \ Hz$ $(A)$ and $262 \ Hz$ $(B)$. Tuning fork $A$ produces a certain number of beats per second with an unknown tuning fork. The same unknown tuning fork produces double the number of beats per second with tuning fork $B$. What is the frequency of the unknown tuning fork in $Hz$?

Beats are produced by two waves $y_1 = a \sin(1000 \pi t)$ and $y_2 = a \sin(998 \pi t)$. The number of beats heard per second is

When temperature increases,the frequency of a tuning fork

The correct figure that shows,schematically,the wave pattern produced by the superposition of two waves of frequencies $9\,Hz$ and $11\,Hz$ is:

Two tuning forks $A$ and $B$ produce $4$ beats per second. The frequency of $A$ is $256 \ Hz$. On loading $B$ slightly,the beat frequency becomes $5$ beats in $2$ seconds. The frequency of $B$ after loading is .... $Hz$