Why Do Light Bulbs Burn Out?
Answer to Last Week’s Question: The top manufacturers of wind turbines in the US are the Distributed Energy Systems corp, Green Energies Technologies, and Earth Wind and Power systems.
This week we worked with light bulbs and how to develop a continuous electrical current involving them. During this process, my group, while conducting some unauthorized experimentation with the bulbs, burnt two of them out (sorry Mr. Couillard). After this event, I began to wonder why bulbs burn out and why some bulbs burn out faster than others. I found the answer from Ask Yahoo.
Why do light bulbs burn out?
To summarize: electrical current flows through the bulb’s filament, a long, super thin, double coil wire made of the metal tungsten. This interaction creates extreme heat around 4,000 degrees and starts a process that causes the atoms to release extra energy in the form of light photons.
At such a high temperature, though, some tungsten atoms will fly off and collect on the inside of the bulb's glass. This loss of tungsten is slowed but not prevented by adding inert gases, typically argon. The argon atoms rebuff the tungsten atoms when they collide, so that some tungsten atoms rebound and rejoin the solid filament. But eventually, as more and more atoms are lost, the filament starts to disintegrate.
The filament is further compromised by the rapid heating and cooling of the wire when the bulb is turned on and off. This creates areas of stress almost like in a paper clip that's repeatedly bent. Eventually, this stress, coupled with the loss of tungsten atoms, weakens the filament enough to break.
http://ask.yahoo.com/2004/1228.html
Question: How are light bulbs made?
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