Two identical stringed instruments have a frequency of $100 \ Hz$. If the tension in one of them is increased by $4\%$ and they are sounded together,then the number of beats produced in one second is:

There are three sources of sound of equal intensity with frequencies $400, 401$ and $402\, vib/sec.$ The number of beats heard per second is

Two tuning forks have frequencies $256 \ Hz$ $(A)$ and $262 \ Hz$ $(B)$. Tuning fork $A$ produces a certain number of beats per second with an unknown tuning fork. The same unknown tuning fork produces double the number of beats per second with tuning fork $B$. What is the frequency of the unknown tuning fork in $Hz$?

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

Beats are produced by frequencies $v_1$ and $v_2$ $(v_1 > v_2)$. The duration of time between two successive minima is

Two tuning forks with frequencies $380 \,Hz$ and $384 \,Hz$ are sounded together. They produce $4$ beats per second. What is the time interval between the maximum sound and the next minimum sound?