PURPOSE: To demonstrate standing sound waves in air excited by convection currents.
DESCRIPTION: A switch is held closed, heating a nichrome wire coil in a vertical four-inch diameter galvanized steel downspout tube, leading to a very loud roar at about 65 Hz, the fundamental frequency of an eight-foot air tube. This is the classic Rijke tube demonstration with an electrical heater replacing a gas burner and screen as the source of the convection currents.
SUGGESTIONS: This experiment is more dramatic than H3-12, which has a shorter tube, but is more difficult to move.
REFERENCES: (PIRA 3D30.70) See Demonstration Reference File for further information about the theory and practice of Rijke tubes.
EQUIPMENT: Four inch diameter ehght foot lomg galvanized steel tube with heater installed on rolling stand.
SETUP TIME: None.
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