Two pipes are each $50\,cm$ in length. One of them is closed at one end while the other is  both ends. The speed of sound in air is $340\,ms^{-1}.$ The frequency at which both the pipes can resonate is

A pulse shown here is reflected from the rigid wall $A$ and then from free end $B.$ The shape of the string after these $2$ reflection will be

A tuning of fork of frequency $392\, Hz$, resonates with $50\, cm$ length of a string under tension $(T)$. If length of the string is decreased by $2\%$, keeping the tension constant, the number of beats heard when the string and the tuning fork made to vibrate simultaneously is

The phase difference corresponding to path difference of $x$ is

A pipe of length $85\, cm$ is closed from one end. Find the number of possible natural oscillations of air column in the pipe whose frequencies lie below $1250\, Hz$. The velocity of sound in air is $340\, m / s$

A point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$are at distances of $2m$ and $3m$ respectively from the source. The ratio of the intensities of the waves at $P$ and $Q$ is