An open organ pipe of length $l$ is sounded together with another open organ pipe of length $(l+l_1)$ in their fundamental modes. Speed of sound in air is $V$. The beat frequency heard will be $(l_1 \ll l)$

An open organ pipe having fundamental frequency $(n)$ is in unison with a vibrating string. If the tube is dipped in water so that $75 \%$ of the length of the tube is inside the water,then the ratio of the fundamental frequency of the air column of the dipped tube to that of the string will be (Neglect end corrections).

When an open pipe is closed from one end, the third overtone of the closed pipe is higher in frequency by $150 \,Hz$ than the second overtone of the open pipe. The fundamental frequency of the open pipe will be: (in $\,Hz$)

$A$ gas is filled in an organ pipe and it is sounded in its fundamental mode. Choose the correct statement$(s)$ : ($T$ = constant)

The number of possible natural oscillations of an air column in a pipe closed at one end of length $85 \, cm$ whose frequencies lie below $1250 \, Hz$ are (Velocity of sound $= 340 \, m s^{-1}$)

An air column in a pipe which is closed at one end will be in resonance with a vibrating tuning fork of frequency $415$ Hz for various vibrating air columns. Which one of the following lengths is not in resonance (in $cm$)? (Velocity of sound in air = $332$ m/s) (Neglect end correction)