The correct figure that shows,schematically,the wave pattern produced by the superposition of two waves of frequencies $9\,Hz$ and $11\,Hz$ is:

$A$ wire under tension $225 \ N$ produces $6$ beats per second when it is tuned with a tuning fork. When the tension changes to $256 \ N$,it is again tuned with the same tuning fork,and the number of beats remains unchanged. The frequency of the tuning fork will be: (in $Hz$)

Two waves $Y_1 = 0.25 \sin(316t)$ and $Y_2 = 0.25 \sin(310t)$ are propagating along the same direction. The number of beats produced per second is:

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

Tuning fork $F_1$ has a frequency of $256 Hz$ and it is observed to produce $6$ beats/second with another tuning fork $F_2$. When $F_2$ is loaded with wax,it still produces $6$ beats/second with $F_1$. The frequency of $F_2$ before loading was ..... $Hz$.

The wavelengths of two sound notes in air are $\frac{40}{195} \,m$ and $\frac{40}{193} \,m$. Each note produces $9$ beats per second separately with a third note of fixed frequency. The velocity of sound in air in $m/s$ is