$A$ tuning fork $A$ of frequency $200 \ Hz$ is sounded with fork $B,$ the number of beats per second is $5.$ By putting some wax on $A,$ the number of beats increases to $8.$ The frequency of fork $B$ is .... $Hz$

If three sources of sound of frequencies $(n-1)$, $n$, and $(n+1)$ are vibrated together, the number of beats produced and heard per second respectively are

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:

Two identical wires have the same fundamental frequency of $400 \text{ Hz}$ when kept under the same tension. If the tension in one wire is increased by $2\%$,the number of beats produced will be

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

$A$ string under a tension of $129.6 \ N$ produces $10 \ beats/s$ when it is vibrated along with a tuning fork. When the tension in the string is increased to $160 \ N$,it sounds in unison with the same tuning fork. Calculate the fundamental frequency of the tuning fork in $Hz$.