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 sound waves travelling in the same direction have displacements $y_1 = a \sin(0.2 \pi x - 50 \pi t)$ and $y_2 = a \sin(0.15 \pi x - 46 \pi t)$. How many times can a listener hear sound of maximum intensity in one second?

$A$ wire vibrates at a fundamental frequency of $500 \,Hz$. $A$ second identical wire produces $5$ beats per second with it when the tension in the first wire is slightly decreased. The ratio of the tension in the second wire to the tension in the first wire is approximately equal to

Two waves of lengths $50 \; cm$ and $51 \; cm$ produce $12$ beats per second. The velocity of sound is .... $m/s$.

Two waves $y_1 = 0.35 \sin(316 t)$ and $y_2 = 0.35 \sin(310 t)$ are propagating along the same direction. The number of beats produced per second is:

$25$ tuning forks are arranged in series in the order of decreasing frequency. Any two successive forks produce $3 \, Hz$ beats. If the frequency of the first tuning fork is the octave of the last fork,then the frequency of the $21^{st}$ fork is .... $Hz$