Why does the light in the light bulb have to be enclosed?

Question

I mean, If there is a hole in the glass of the light bulb, why wont the light work? And if you have an idiot answer, i dont want to hear it!!!!! Thanks

Also, when I was in the 5th grade, (1996) I watched a movie stating that the element that makes the light will no longer be aviliable in the next 20 years or so. That the earth would run out of it soon. Is that true?

Answer 1

Yes what the others say it's true, but regarding the Tungsten (also Wolfram) supplies, they are estimated at 7 million tons, which should last round 140 years. Plus, most of these reserves are not "economically workable". Which means we should start recycling Wolfram at a much bigger scale than it is done today. (in my country we just throw bulbs away).

Answer 2

If there is a hole in the glass of a light bulb and you turn it on, the filament (the wire which lights up) will burn out immediately. A light bulb is enclosed so that it can hold a gas around the filament which does not support oxidation, the process which causes the filament to burn out.

Answer 3

Hi. A filament that works by resistance heating the tungsten, say, needs either a vacuum or, in the case of a halogen light, a gas. The newer spring fluorescent lights sometimes use a globe to enclose the fragile tube. A G45 is a good example.

Answer 4

In an incandescent light bulb, the tungsten filament operates at a very high temperature. If exposed to oxygen, it will quickly oxidize and burn out. A fluorescent bulb has a partial vacuum, and depends on this to carry electricity. If air gets in, it acts as an insulator and the current cannot flow.

Answer 5

if there was a hole in the glass portion of the bulb, it would burn out. oxygen is one of the important elements needed to make fire. when you see a bulb light up you are seeing a glow created by the resistance of electric current trying to move through the filament. some bulbs are purged of oxygen. without oxygen, the filament won't burn up (there is no fuel).

Answer 6

It took edison hundreds of tries before he found that he had to seal the light bulb and have an inert gas in the bulb to keep the tungsten filament glowing and not burning up Argon is the inert gas in the bulb, which does not support combustion.

Answer 7

To be incandescent, the filament is very hot, and would react with oxygen in the air and burn out. The bulb is filled with a non-reactive gas to prevent this.

Answer 8

The light is made by heating a wire up until it's white hot. The wire has to be kept in a vacuum so it won't burn up. The glass is to hold the vacuum.

Answer 9

Everyone made it way too complicated. The heated wire cannot be exposed to O2 because O2 will make it burn much faster. Fire for example runs on 02. If the wire were exposed to the air's O2 then it would burn up quickly and the wire would disintegrate. :)

Answer 10

In order for the light bulb to work, it must be an airtight vacuum.