In a resonance column lab experiment to measure the velocity of sound,the first resonance is obtained at a length $l_1$ and the second resonance at a length $l_2$. Then-

Two closed organ pipes of length $100 \,cm$ and $101 \,cm$ produce $16$ beats in $20 \,s$. When each pipe is sounded in its fundamental mode,calculate the velocity of sound in $m/s$.

In the fundamental mode,the time required for a sound wave to reach the closed end of an air-filled pipe is $t$ seconds. What is the frequency of vibration of the air column?

$A$ closed pipe of length $300 \,cm$ contains some sand. $A$ speaker is connected at one of its ends. The frequency of the speaker at which the sand will arrange itself in $20$ equidistant piles is close to .......... $kHz$ (velocity of sound is $300 \,m/s$).

$A$ student performed an experiment to measure the speed of sound in air using the resonance air-column method. Two resonances in the air-column were obtained by lowering the water level. The resonance with the shorter air-column is the first resonance and that with the longer air-column is the second resonance. Then,

The length of an open organ pipe is twice the length of another closed organ pipe. The fundamental frequency of the open pipe is $100 \ Hz$. The frequency of the third harmonic of the closed pipe is ..... $Hz$.