The interior surface of an oven of internal dimensions 1mx1mx1m has an emissivity of 0.8, and is maintained at a uniform temperature of 500 K. The oven is placed in a very large room where the ambient temperature is 300K. On the front wall of the oven is a square opening of dimensions 100mmx100mm. To reduce the heat loss through the opening, a thin metallic plate is used to cover the opening. The emissivity of the cover plate surface facing the oven interior is 0.2, while the cover plate surface facing the surroundings is 0.1. Heat transfer by convection may be assumed to be negligible compared to that by radiation. (a) Treating the interior surface of the oven as a single surface, construct the radiation network for calculating radiation heat loss through the cover plate. (6 marks) (b) What is the rate of heat loss from the oven through the cover plate? (c) What is the temperature of the cover plate? (14 marks) (5 marks)