$56$ 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 $\text{Hz}$)

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

Two waves $y = 0.25 \sin(316t)$ and $y = 0.25 \sin(310t)$ are travelling in the same direction. The number of beats produced per second will be:

Draw graphs of beats produced by two harmonic waves of frequency $11 \ Hz$ and $9 \ Hz$.

During the superposition of two waves of nearly equal frequencies,the beat frequency is defined as the:

$A$ tuning fork $A$,marked $512 \ Hz$,produces $5$ beats per second when sounded with another unmarked tuning fork $B$. If $A$ is loaded with wax,the number of beats is again $5$ per second. What is the frequency of the tuning fork $B$ when not loaded (in $Hz$)?