If the lengths of the open and closed pipes are in the ratio of $2 : 3$, then the ratio of the frequencies of the third harmonic of the open pipe and the fifth harmonic of the closed pipe is

The fundamental frequency of a closed pipe is $220 \ Hz$. If $\frac{1}{4}$ of the pipe is filled with water,the frequency of the first overtone of the pipe now is ..... $Hz$.

In a resonance tube of length $0.8 \,m$, an air column vibrates with a source of frequency $375 \,Hz$ for a certain height of water from the bottom of the tube. What is the water level corresponding to the fundamental frequency (in $\,m$)? (Neglect end correction, speed of sound in air = $330 \,m/s$)

$A$ pipe of $30 \text{ cm}$ long and open at both ends produces harmonics. Which harmonic mode of the pipe resonates with a $1.1 \text{ kHz}$ source? (Given: speed of sound in air $v = 330 \text{ ms}^{-1}$)

$A$ closed pipe is suddenly opened and changed to an open pipe of the same length. The fundamental frequency of the resulting open pipe is less than that of the $3^{rd}$ harmonic of the earlier closed pipe by $55 \,Hz$. Then, the value of the fundamental frequency of the closed pipe is: (in $\,Hz$)

$A$ closed organ pipe of length $1.2 \, m$ vibrates in its first overtone mode. The pressure variation is maximum at: