Two concentric spheres of diameter D₁ = 0.8 m and D2 = 1.2 m are separated by an air space and have surface temperatures

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Two Concentric Spheres Of Diameter D 0 8 M And D2 1 2 M Are Separated By An Air Space And Have Surface Temperatures 1 (52.87 KiB) Viewed 26 times

Two concentric spheres of diameter D₁ = 0.8 m and D2 = 1.2 m are separated by an air space and have surface temperatures of T1 = 390 K and T2 = 300 K. (a) If the surfaces are black, what is the net rate of radiation exchange between the spheres, in W? 912= i W (b) What is the net rate of radiation exchange between the surfaces if they are diffuse and gray with 1 = 0.5 and 2 = 0.05, in W? 912= i W (c) What is the net rate of radiation exchange if D2 is increased to 20 m, with 2 = 0.05, 1 = 0.5, and D₁ = 0.8 m, in W? 912= W (d) What is the net rate of radiation exchange if the larger sphere behaves as a black body (2= 1.0) and with 1 = 0.5, D2 20 m, and D₁ = 0.8 m, in W? 912= i W