An air column in a closed organ pipe vibrating in unison with a tuning fork produces the second overtone. The vibrating air column has:

The vibrations of four air columns are shown below. The ratio of frequencies is

$A$ closed organ pipe of length $L_c$ and an open organ pipe of length $L_o$ contain different gases of densities $\rho_1$ and $\rho_2$ respectively. The compressibility of the gases is the same in both the pipes. The gases are vibrating in their first overtone with the same frequency. What is the length of the open organ pipe?

$A$ 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 $\,Hz$)

The length of an open organ pipe is $0.5\, m$. Calculate the fundamental frequency of the pipe,if the velocity of sound in air is $350\, m/s$.

The number of possible natural oscillations of an air column in a pipe closed at one end of length $85 \, cm$ whose frequencies lie below $1250 \, Hz$ are (Velocity of sound $= 340 \, m s^{-1}$)