Calculate the electric power which must be supplied to the filament of of a light bulb operating at 3000K. The total surface area of the filament is 8×10−6m2 and its emissivity is 0.92.

Question

anonymous · Answer

Use the Stefan-Boltzmann constant to calculate the power radiated by a black body and then get the lamp radiated power ussing emissivity ratio

anonymous · Answer

you can use Stefan–Boltzmann law.


  $$P=A \epsilon  \sigma T^4$$

where 

A : Total surface 

e: emissivity 

sigma: Stefan–Boltzmann constant 

then you can get 33,8 watt.

anonymous · Answer

you answer is 
confirmed thanks