Find the emissive power from "0.3 cm"^(2) surface of filament of bulb of tungsten at 3000 K temperature. Take e=0.4 for tungsten bulb.

Find the emissive power from "0.3 cm"^(2) surface of filament of bulb

1.	Find the emissive power from "0.3 cm"^(2) surface of filament of bulb of tungsten at 3000 K temperature. Take e=0.4 for tungsten bulb.
Answer» Solution :From Stefan - Boltzmaan law, `H=AesigmaT^(4)` `=0.3xx10^(-4)xx0.4xx5.67xx10^(-8)xx(3000)^(4)` `=55.1124` `:.` H `~~` 60 W (Acc. to textbook VALUE)