In an open organ pipe,if the fundamental frequency is $n$,then the other frequencies are:

The fundamental frequency of a closed pipe is $400 \,Hz$. If $1/3$ of the pipe is filled with water,the frequency of the $2^{\text{nd}}$ harmonic of the pipe will be (Neglect end correction). (in $\,Hz$)

$A$ sufficiently long closed organ pipe has a small hole at its bottom. Initially,the pipe is empty. Water is poured into the pipe at a constant rate. The fundamental frequency of the air column in the pipe

$A$ cylindrical tube,open at both ends,has a fundamental frequency $f_0$ in air. The tube is dipped vertically into water such that half of its length is inside water. The fundamental frequency of the air column now is

$A$ tuning fork is vibrating at $250\, {Hz}$. The length of the shortest closed organ pipe that will resonate with the tuning fork will be ..... ${cm}$.
(Take speed of sound in air as $340\, {ms}^{-1}$)

Obtain the equation for the frequency of a stationary wave produced in an open pipe and show that all harmonics are possible in it.