Demonstrates wave interference using sound waves. Two sine waves with audible frequencies are generated by two signal generators and the output is feed to a single speaker. When the frequencies are close enough, the students can hear the beats and count them using their stop watches. The output from the generators is also passed to an oscilloscope where the frequencies of the signal generators can bemeasured. The beats can also be visualized in the scope and if the twosources are made to produce waves with the same amplitude, then totaldestructive interference can be illustrated. Also given one of the frequencies feed to the speaker, you may also ask the students to estimate the frequency of the other source, just by counting the beats.
ID: d0004
Set up time:
10 min in the prep room + 2 minutes in class.
Requires:
Electricity outlet and extension cord. Components.
Notes:
You may need assistance the first time you use this demo.Make sure that you have at least 5 Vpp from the signal generator.A frequency of around 300Hz seems to work fin, 600 Hz is still OK; 900Hz is closer to being unpleasant. Should bring at least a couple of stop watches to the class.
