Question

A student sets up the speed of sound in air apparatus for finding the velocity of sound in air, at the room temperature. Using a tuning fork, of frequency n (Hz), she obtains the first and second positions of resonance for lengths l₁ (m) and l₂ (m) , respectively, of the air column, in the resonance tube. The velocity of sound, V(in m/s), would then be best given by the formula.

(1) V = 4l₁n

(2) V = 4/3 l₂n

(3) V = 2(l₂ - l₁)n

(4) V = (l₂ + l₁)n

Answer 1

(3) V = 2(l₂ - l₁)n

The velocity, V, is, therefore, given by

[Note: It is only this formula for V that is independent of the ‘end–correction’].