Question

A body of emissivity `(e = 0.75)`, surface area of `300cm^(2)` and temperature `227^(@)C` is kept in a room at temperature `27^(@)C`. Calculate the initial value of net power emitted by the body.

Answer 1

Using equation `(13.3) P = e sigma A(T^(4)-T_(0)^(4))`
`= (0.75) (5.67 xx 10^(-8) W//m^(2) -K^(4)) (300 xx 10^(-4)m^(2)) xx {(500 K)^(4) -(300K)^(4)}`
`= 69.4` Watt.