For a surface, the direct and diffuse components of the solar radiation are 400 and 300 W/m2 and the direct radiation makes 60 deg angle with the normal. If the surface temperature is 300 K and effective sky temperature is 200 K, calculate the net rate of radiation heat transfer. (Assume solar absorptivity and emissivity as 0.1 each; For calculation Take Stefan Boltzmann's constant as 6 × 10-8 W/m2.K4)

For a surface, the direct and diffuse components of the solar radiatio

1.	For a surface, the direct and diffuse components of the solar radiation are 400 and 300 W/m2 and the direct radiation makes 60 deg angle with the normal. If the surface temperature is 300 K and effective sky temperature is 200 K, calculate the net rate of radiation heat transfer. (Assume solar absorptivity and emissivity as 0.1 each; For calculation Take Stefan Boltzmann's constant as 6 × 10-8 W/m2.K4)
A.	11 W/m2
B.	45 W/m2
C.	33 W/m2
D.	64 W/m2
Answer» B. 45 W/m2