The frequency of a tuning fork is $220 \,Hz$ and the velocity of sound in air is $330 \,m/s$. When the tuning fork completes $80$ vibrations, the distance travelled by the sound wave is: (in $\,m$)

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 $Hz$)?

$A$ tuning fork of known frequency $256\,Hz$ produces $5$ beats per second with the vibrating string of a guitar. The beat frequency decreases to $2$ beats per second when the tension in the guitar string is slightly increased. The frequency of the guitar string before increasing the tension was ..... $Hz$.

Two tuning forks when sounded together produce $4$ beats/sec. The frequency of one fork is $256 \, Hz$. The number of beats heard increases when the fork of frequency $256 \, Hz$ is loaded with wax. The frequency of the other fork is (in $, Hz$)

Two tuning forks $P$ and $Q$ are vibrated together. The number of beats produced are represented by the straight line $OA$ in the following graph. After loading $Q$ with wax,they are vibrated together again and the beats produced are represented by the line $OB$. If the frequency of $P$ is $341 \ Hz$,the frequency of $Q$ will be ... $Hz$.

When two tuning forks (fork $1$ and fork $2$) are sounded simultaneously,$4$ beats per second are heard. Now,some tape is attached to the prong of fork $2$. When the tuning forks are sounded again,$6$ beats per second are heard. If the frequency of fork $1$ is $200 \, Hz$,then what was the original frequency of fork $2$ (in $, Hz$)?