An electronically driven loudspeaker is placed near the open end of a resonance column apparatus. The length of air column in the tube is 80 cm. The frequency of the loudspeaker can be varied between 20 Hz and 2 kHz. Find the frequencies at which the column will resonate. Speed of sound in air = 320 m s^-1.

Given:
Length of air column in the tube

Speed of sound in air

The frequency of the loudspeaker can be varied between 20 Hz to 2 KHz.

The resonance column apparatus is equivalent to a closed organ pipe.

Fundamental note of a closed organ pipe is given by:

So, the frequency of the other harmonics will be odd multiples of f:

According to the question, the harmonic should be between 20 Hz and 2 kHz.