The fundamental frequency of an air column in a pipe open at both ends is $f_1$. Now $80\%$ of its length is immersed in water,the fundamental frequency of the air column becomes $f_2$. The ratio of $f_1:f_2$ is

At a temperature of $27^{\circ} C$, two identical organ pipes produce notes of frequency $140 \,Hz$. If the temperature of one pipe is raised to $57.75^{\circ} C$, then the number of beats produced per second is

An air column in a pipe which is closed at one end will be in resonance with a vibrating tuning fork of frequency $415$ Hz for various vibrating air columns. Which one of the following lengths is not in resonance (in $cm$)? (Velocity of sound in air = $332$ m/s) (Neglect end correction)

Which order of harmonics is missing or absent in case of stationary sound waves produced in a closed pipe?

Tube $A$ has both ends open while tube $B$ has one end closed,otherwise they are identical. The ratio of the fundamental frequency of tube $A$ to tube $B$ is

$A$ cylindrical tube open at both ends has a fundamental frequency $f$ in air. The tube is dipped vertically in water so that $60 \%$ of the tube is in water. Then the fundamental frequency of the air column is