Two sound waves of wavelengths $99 \ cm$ and $100 \ cm$ produce $10$ beats in a time of $t$ seconds. If the speed of sound in air is $330 \ m \ s^{-1}$,then the value of $t$ in seconds is

$A$ 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 ..... $Hz$.

$A$ prong of a vibrating tuning fork is in contact with the water surface. It produces concentric circular waves on the surface of the water. The distance between five consecutive crests is $0.8 \ m$ and the velocity of the wave on the water surface is $56 \ m/s$. The frequency of the tuning fork is: (in $Hz$)

Two tuning forks of frequencies $256 \ Hz$ and $258 \ Hz$ are sounded together. The time interval between two consecutive maxima is (in $s$)

Two sound waves of slightly different frequencies have an amplitude ratio of $11/9$. What is the difference in sound levels (in decibels) between the maximum and minimum intensities heard at a point?

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 .... $Hz$