Two very large parallel plates are maintained at uniform temperatures of T1 = 800 K and T2 = 500 K and have emissivities ϵ 1 = 0.2 and ϵ 2 = 0.7 respectively. Determine the net rate of radiation heat transfer between the two surfaces per unit area of the plates. Two very large parallel plates are maintained at uniform temperatures of T1 = 800 K and T2 = 500 K and have emissivities ϵ 1 = 0.2 and ϵ 2 = 0.7 respectively. Determine the net rate of radiation heat transfer between the two surfaces per unit area of the plates.