$A$ closed organ pipe $150 \ cm$ long gives $7$ beats per second with an open organ pipe of length $350 \ cm$,both vibrating in fundamental mode. The velocity of sound is . . . . . . $m/s$.

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

The length of a closed and an open pipe is the same. The ratio of the frequency of the $n^{\text{th}}$ overtone for the closed pipe to that of the open pipe is (Neglect end correction).

The fundamental frequency of an air column in a pipe closed at one end is $150 \ Hz$. If the same pipe is open at both ends,the frequencies produced in $Hz$ are:

The fundamental frequency of a pipe is $100 \ Hz$ and the next two frequencies are $300 \ Hz$ and $500 \ Hz$. Then,the pipe is:

$A$ pipe open at both ends produces a fundamental frequency $n_1$. When the pipe is kept with $\frac{3}{4}$ of its length in water,it produces a note of fundamental frequency $n_2$. The ratio of $\frac{n_1}{n_2}$ is