Question

The temperature and the surface area of the body are `227^(@)C` and `0.15 m` respectively. If its transmitting power is negligible and reflecting power is `0.5`, then calculate the thermal power of the body.
(Given `sigma-5.67xx10^(-4)J//m^(2)//s//K`)
A. `300W`
B. `265.78W`
C. `201W`
D. `320.89W`

Answer 1

(b) Absorbing power of a body is equal to emissivity of the body.
And also `a+r+t=1implies0+0.5+a=1`
`a=0.5, epsilona=0.5`
`Q/t=epsilon sigma AT^(4)=(0.5)(5.67)xx10^(-8)(0.15)xx(273+227)^(4)`
`Q/t=265.78W`