Why is a Tungsten filament used in incandescent bulbs? (Factual Question)

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SUMMARY

Tungsten is used as a filament in incandescent bulbs primarily due to its exceptionally high melting point of 3380°C, which allows it to operate at high temperatures necessary for producing visible light. Despite having a low resistivity of 5.2 x 10^-8 ohm-meters, the key factor for tungsten's selection is its ability to withstand high temperatures without melting. This property ensures that the filament can generate light efficiently while minimizing energy loss through heat. The combination of high melting point and adequate conductivity makes tungsten the optimal choice for incandescent bulb filaments.

PREREQUISITES
  • Understanding of Joule's law of heating
  • Basic knowledge of electrical resistance and resistivity
  • Familiarity with material properties, specifically melting points
  • Concept of thermal conductivity in metals
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Homework Statement


Why is a tungsten filament used in incandescent bulbs?

I earlier thought that it was due to the high resistivity of tungsten , but i was wrong , the resistivity of tungsten is low at 5.2 * 10^-8 Is it due to its high melting point?? I can't figure out as high melting point doesn't seem to be the only reason for selection of Tungsten.
Please Help.
Thank You
 
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What physical properties do you want from a lamp filament ?
hint - What does Tungsten have the highest of ?
 
i think it should be high melting point ( Tungsten has a MP of 3380 C) but again , it has a very low resistivity which means it has a low resistance. So according to Joule's law of heating , a very less amount of heat would be produced . What are your views on this?
 
You want less heat - it's wasted energy but that's a secondary point.

The important point is that to get visible light you need the filament to be as hot as possible, an the lamp will fail when the filament melts - so you need the highest melting point material possible (that is also a conductor of course)
 
I get it , so the main reason is melting point! Thanks a ton , i have an exam tommorow , this will surely help!
 

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