PURPOSE: To show what would happen to a lighted filament in the presence of air.
DESCRIPTION: Run the carbon filament in the evacuated light bulb at about 80 volts to demonstrate how a light filament functions. Let air into the bulb and the filament will very quickly burn out.
REFERENCES: (PIRA unknown.)
EQUIPMENT: Vacuum system, variac, bulb with filament mount, carbon filaments with steel wool for contacts.
SETUP TIME: 5 min.
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