Oscillations and Waves > Instruments > Air Columns DCS# 3D30.60
KUNDT'S TUBE

APPARATUS
 
glass cylinder with stopper
 202-17-E3
cork dust
 202-17-E3
function generator
 202-08-G
amplifier 202-09-E
speaker
 202-12-B
hearing protection
 202-01-B
camera 202-09-D

DESCRIPTION Tune the function generator to a resonance frequency of the tube and the cork dust will settle at the displacement nodes.

The length L of the stoppered glass tube is 0.440 m, its inner diameter d is 0.046 m, so its effective length taking into account the end correction is L + 0.31*d = 0.454 m.  The resonance frequencies are odd multiples of vs/4Leff: about 190, 570, 950, 1330, 1710 Hz etc. NOTES

The closely-spaced ripples in the cork dust are due to vortices in the air column.  See: AJP, Nov. 1955, Volume 23, Issue 8, pp. 505.

The shorter glass tube can be displayed on the document camera and requires less sound volume.  Its length is 0.380 m, its inner diameter is 0.022 m, and the resonances occur at odd multiples of 220 Hz.



REFERENCES

Sutton S-82.