6B40.10 - Variac and Light Bulb

Code Number:
Demo Title:
Variac and Light Bulb
Radiant Color vs. Temperature
Area of Study:
Light bulbs (1000 W), Socket, Variac.

See also 6B40.10 in Optics.

Video Credit: Jonathan M. Sullivan-Wood.

Put the 1 KW light bulb onto the variac and turn up slowly.  At low voltages the large filament area should look red to a dull orange.  As you now slowly turn up the voltage the filament will get hotter and the corresponding color will be more and more towards white.

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