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

$A$ closed organ pipe has length $L$. The air in it is vibrating in the third overtone with a maximum amplitude $a$. The amplitude at a distance $\frac{L}{7}$ from the closed end of the pipe is:

An open air pipe of length $80 \,cm$ has the second harmonic frequency equal to the fundamental frequency of a closed organ air pipe. The length of the closed pipe is (in $\,cm$)

$A$ tuning fork of frequency $340 \, Hz$ is sounded above an organ pipe of length $120 \, cm$. Water is now slowly poured in it. The minimum height of water column required for resonance is .... $cm$ (speed of sound in air $= 340 \, m/s$)

For a certain organ pipe, three successive resonance frequencies are observed at $425 \,Hz$, $595 \,Hz$, and $765 \,Hz$, respectively. The length of the pipe is (speed of sound in air $= 340 \,m/s$). (in $\,m$)

In a resonance tube experiment,the first resonance is obtained for $10\, cm$ of air column and the second for $32\, cm$. The end correction for this apparatus is ....$cm$