Two sound sources,when sounded simultaneously,produce four beats in $0.25 \ s$. The difference in their frequencies must be: (in $Hz$)

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 stretched strings $A$ and $B$ when vibrated together produce $4$ beats per second. If the tension applied to the string $A$ is increased,the number of beats produced per second increases to $7$. If the frequency of string $B$ is $480 \ Hz$ initially,what is the frequency of string $A$ (in $Hz$)?

It is possible to hear beats from two vibrating sources of frequency:

$A$ wire having tension $225 \ N$ produces six beats per second when it vibrates with a tuning fork. When the tension changes to $256 \ N$,it vibrates with the same fork,and the number of beats per second remains unchanged. The frequency of the fork is: (in $Hz$)

The frequencies of three tuning forks $A$,$B$,and $C$ are related as $n_{A} > n_{B} > n_{C}$. When the forks $A$ and $B$ are sounded together,the number of beats produced per second is $n_1$. When forks $A$ and $C$ are sounded together,the number of beats produced per second is $n_2$. How many beats are produced per second when forks $B$ and $C$ are sounded together?