The sound waves of wavelengths $5 \,m$ and $6 \,m$ produce $30$ beats in $3 \,s$. The velocity of sound is (in $\,m/s$)

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

Two tuning forks have frequencies $450\, Hz$ and $454\, Hz$ respectively. On sounding these forks together,the time interval between successive maximum intensities will be .... $sec$

Two vibrating tuning forks produce progressive waves given by $y_1 = 4 \sin(500 \pi t)$ and $y_2 = 2 \sin(506 \pi t)$. These tuning forks are held near the ear of a person. The person will hear

$56$ tuning forks are arranged such that each fork produces $4$ beats per second with its previous one. If the frequency of the last fork is twice that of the first, the frequency of the $19^{\text{th}}$ fork is . . . . . . (in $\text{Hz}$)

Beats are the result of