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

Two tuning forks $A$ and $B$ produce notes of frequencies $256 \ Hz$ and $262 \ Hz$ respectively. An unknown note sounded at the same time as $A$ produces beats. When the same note is sounded with $B$,the beat frequency is twice as large. The unknown frequency could be ... $Hz$

$A$ tuning fork and an air column whose temperature is $51^{\circ} C$ produce $4$ beats in one second,when sounded together. When the temperature of the air column decreases,the number of beats per second decreases. When the temperature is $16^{\circ} C$,only one beat per second is produced. The frequency of the tuning fork is ........... $Hz$.

The frequencies of tuning forks $A$ and $B$ are respectively $3\%$ more and $2\%$ less than the frequency of tuning fork $C$. When $A$ and $B$ are simultaneously excited,$5$ beats per second are produced. Then the frequency of the tuning fork $A$ (in $Hz$) is

The wavelength of one wave is $99 \ cm$ and that of another is $100 \ cm$. If the speed of sound is $396 \ m/s$,the number of beats heard per second is:

Beats are the result of