Wb-3 The Gas Tube
Aim
To demonstrate standing wave patterns in a pipe using sound waves and gas jets to indicate the pressure profile.
Apparatus
- Horn Loudspeaker
- Signal Generator
- PA Amplifier
- Gas Tube
Gas Tube Setup and Wave Formation.
Description
A metre long pipe has a series of small holes drilled equidistant along its length and is connected to a natural gas supply. At the other end a horn loudspeaker is driven by the Minilab signal generator and power amplifier combination. The gas supply is adjusted to give a flame height of approximately 2 inches.As the frequency is varied , standing waves are produced, pressure maxima and minima are formed in the pipe, as indicated by the height of the flames.
The following frequencies produced the indicated modes.
The following frequencies produced the indicated modes.
frequency (Hz) | Mode (Number of wavelengths) |
200 | 1/4 |
400 | 1/2 |
800 | 1 |
1600 | 2 |