Question

A resonance air column of length 20 cm resonates with a tuning fork of frequency 450 Hz. Ignoring the correction, the velocity of sound in air will be

(a) 920 m/s

(b) 720 m/s

(c) 820 m/s

(d) 360 m/s

Answer 1

Correct option  (d) 360 m/s

Explanation:

The minimum length of the air column in a resonance tube corresponds to the fundamental mode of vibrations. Hence by ignoring end correction.

Resonant frequency v = 450 Hz

∴ Speed of sound v = vλ = 450 x 0.8 = 360 m/s