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How does a flashlight work
There are 2 important parts to a flashlight. The first part is the
battery and switch. When you flip the switch or press the button, it
connects the battery to the light bulb. That way, you save energy.
The more interesting part is the light bulb. Inside the light bulb
is a tiny wire of a special material called tungsten. When electricity
goes through the wire, it heats up and sends out a lot of light in all
directions. Some of the light goes backwards into the handle so
flashlights have a metal reflector to bounce that light back forward.
That way, none of the light is wasted.
(republished on 07/28/06)
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