Two large parallel grey plates with a small gap exchange radiation at a rate of 1000 W/m2, when their emissivities are 0.5 each. One plate is cooled such that its emissivity becomes 0.25. Find the new rate of heat transfer if the temperature difference remains the same.

Two large parallel grey plates with a small gap exchange radiation at

1.	Two large parallel grey plates with a small gap exchange radiation at a rate of 1000 W/m2, when their emissivities are 0.5 each. One plate is cooled such that its emissivity becomes 0.25. Find the new rate of heat transfer if the temperature difference remains the same.
A.	850 W/m2
B.	550 W/m2
C.	600 W/m2
D.	1000 W/m2
Answer» D. 1000 W/m2