In the resonance experiment,two air columns (closed at one end) of $100 \ cm$ and $120 \ cm$ long,give $15$ beats per second when each one is sounding in the respective fundamental modes. The velocity of sound in the air column is $:$ (in $m/s$)

$A$ cylindrical tube open at both ends has a fundamental frequency of $390 \,Hz$ in air. If $\frac{1}{4}$th of the tube is immersed vertically in water, what is the fundamental frequency of the air column (in $\,Hz$)?

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:

$A$ standing wave in a pipe with a length $L=1.2 \,m$ is described by $y(x, t)=y_0 \sin [(2 \pi / L) x] \sin [(2 \pi / L) x+\pi / 4]$. Based on the above information,which one of the following statements is incorrect? (Speed of sound in air is $300 \,ms^{-1}$)

The fundamental frequency of an open pipe is $n$. If it is closed from one end, then the frequency of the $2^{nd}$ harmonic of the closed pipe is higher by $200 \,Hz$ than $n$. The value of $n$ is: (in $\,Hz$)

For air at room temperature, the atmospheric pressure is $1.0 \times 10^{5} \text{ Nm}^{-2}$ and the density of air is $1.2 \text{ kgm}^{-3}$. For a tube of length $1.0 \text{ m}$, closed at one end, the lowest frequency generated is $84 \text{ Hz}$. The value of $\gamma$ (ratio of two specific heats) for air is: