Wb-5 Chladni Figures (Acoustically driven)
Published: Tuesday 14 March 2006 - Updated: Wednesday 30 March 2011
To demonstrate the modes of vibration of a plate.
- Signal Generator
- Public Address Amplifier
- 50 Watt Horn Loudspeaker
- Chladni Plates
- Stand as Shown
- Bell Jar
- TV Camera and Monitor
Click on pictures to enlarge.
A plate supported at its centre is mounted a few millimetres above a horn loudspeaker driven by a signal generator and public address amplifier. Salt is spread across the surface and accumulates along nodal lines upon excitation. The apparatus is enclosed within a bell jar to reduce the sound level to acceptable levels. Modes of vibration are quite easily observed. Listed below are some frequencies that produce useful results. It will be observed that finer particles congregate at the antinodes. This is explained by the fact that these particles are predominately under the influence of the air motion caused by the vibrating plate.