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Light Bulb

  • Thread starter ritwik06
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A light bulb is completely covered with a thin coat of black soot in a room maintained at 20 degree celsius. If the shell has an equilibrium temperature of 100 degree celsius. What is the wattage of the bulb?

I cant understand how to do it. I am a student of 9th standard.
 

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  • #2
Andrew Mason
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ritwik06 said:
A light bulb is completely covered with a thin coat of black soot in a room maintained at 20 degree celsius. If the shell has an equilibrium temperature of 100 degree celsius. What is the wattage of the bulb?

I cant understand how to do it. I am a student of 9th standard.
Do they give you the radius or area of the lightbulb?

AM
 
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Andrew Mason said:
Do they give you the radius or area of the lightbulb?

AM
No nothing at all!!!!!!!!!!!!!!!!!!! I have provided everything given at the question. If it isnt possible just tell me a way hot to prove that the given data is insufficient. :smile:
 
  • #4
OlderDan
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ritwik06 said:
No nothing at all!!!!!!!!!!!!!!!!!!! I have provided everything given at the question. If it isnt possible just tell me a way hot to prove that the given data is insufficient. :smile:
This should give you what you need. The size of the bulb does matter.

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html#c1
 

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