Consider an enclosure formed by three surfaces having the following values of shape factors, emissivities and temperatures.Surface 1 i.e. curved cylindrical has an emissivity 0.75 and temperature 800 KSurface 2 i.e. closing disc has an emissivity 0.8 and temperature 700 KSurface 3 i.e. closing disc has an emissivity 0.8 and temperature 700 KThe closing flat discs are 25 mm in diameter and they have interspacing distance equal to 100 mm. If the shape factor between these two identical discs is 0.05, calculate the net rate of radiant heat flow from the curve surface to each of the closing end surface.

• A. 1.561 W
• B. 2.561 W
• C. 3.561 W
• D. 4.561 W