The energy radiated per hour from the surface of a filament 0.5 cm long and of radius 0.32 cm of an incandescent lamp at a certain temperature is 2.625xx10^(5) J. If the relative emittance of the surface is 0.8 calculate the temperature of the filament.

The energy radiated per hour from the surface of a filament 0.5 cm lon

1.	The energy radiated per hour from the surface of a filament 0.5 cm long and of radius 0.32 cm of an incandescent lamp at a certain temperature is 2.625xx10^(5) J. If the relative emittance of the surface is 0.8 calculate the temperature of the filament.
Answer» Solution :`T=[Q//eA sigma t]^(1//4),Q=2.655xx10^(4)J, A=2pirl,=2pixx0.32xx10^(-2)xx0.5xx10^(-2)m^(2),T=200 K`