PURPOSE: To demonstrate the origin of standing waves from one source and its reflection.
DESCRIPTION: A loudspeaker is driven at about 3000 Hz by a sine wave oscillation which is displayed on the top trace of the oscilloscope. The standing wave pattern, created by the sound from the speaker and the wave reflected off the flat metal plate, is picked up by a microphone sliding along the optical rail and displayed on the lower trace of the oscilloscope.
REFERENCES: (PIRA unavailable.) See also demonstration H3-01: STANDING SOUND WAVES - TWO SOURCES, which uses the same setup except a second loudspeaker replaces the plane reflector.
EQUIPMENT: Audio oscillator, small speaker, plane reflector and microphone on optical rail, audio amplifier, and dual trace oscilloscope.
SETUP TIME: 10 min.
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