Two tuning forks of frequencies $320 \ Hz$ and $323 \ Hz$ are vibrated together. The time interval between a maximum sound and its adjacent minimum sound heard by an observer is

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 $\,m$)

$A$ tuning fork $A$ of frequency $250 \,Hz$ and another tuning fork $B$ of frequency $x$ produce $5$ beats per second when vibrated together. If the fork $B$ is waxed and vibrated together with $A$, then $3$ beats per second are produced. Then $x=$ (in $\,Hz$)

Two identical straight wires are stretched so as to produce $6$ beats per second when vibrating simultaneously. On changing the tension in one of them,the beat frequency remains unchanged. Denoting by ${T_1}$ and ${T_2}$ the higher and the lower initial tensions in the strings,respectively,then it could be said that while making the above change in tension:

$A$ 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 $Hz$)

For the formation of beats,two sound notes must have: