A blackbody of surface area `10cm^(2)` is heated to `127^(@)C` and is suspended in a room at temperature `27^(@)C`. Calculate the initial rate of loss of heat from the body to the room.

Options

A. 0.5 W
B. 1 W
C. 1.5 W
D. 2 W

Answer

B

Explanation

According to Stefan Boltzmann's law the initial rate of loss of heat from the body to the surrounding is
`(dQ)/(dt)=sigmaA[T_(1)^(4)-T_(2)^(4)]`
`=5.67xx10^(-8)xx10xx10^(-4)[400^(4)-300^(4)]`
`=5.67xx10^(-11)xx10^(8)[4^(4)-3^(4)]`
`=5.67xx10^(-3)[256-81]`
`=175xx5.67xx10^(-3)=1W`