$A$ person blows into the open end of a long pipe. As a result,a high-pressure pulse of air travels down the pipe. When this pulse reaches the other end of the pipe:

$A$ resonance tube completely filled with water has a small hole at the bottom. Length of the tube is $0.8 \ m$. $A$ vibrating tuning fork of frequency $500 \ Hz$ is held near the open end of the tube. Water is slowly removed from the bottom. The maximum number of resonances heard will be (Neglect end correction. Speed of sound in air $= 340 \ m/s$).

Two open organ pipes of fundamental frequencies $n_{1}$ and $n_{2}$ are joined in series. The fundamental frequency of the new pipe is

$A$ 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 $\,Hz$)

An organ pipe with both ends open has a length $L=25 \,cm$. An extra hole is created at position $\frac{L}{2}$. The lowest frequency of sound produced is (assume, speed of sound $=340 \,m/s$) (in $\,Hz$)

An empty vessel is partially filled with water. What happens to the frequency of vibration of the air column in the vessel?