(Solved): A solid sphere of radius 11 = 20 mm is placed concentrically inside the hollow sphere of radius 12 ...

A solid sphere of radius 11 = 20 mm is placed concentrically inside the hollow sphere of radius 12 = 30 mm. The View factor F21 for the radiation of heat transfer is O 2/3 O 4/9 O 8/27 9/4 QUESTION 11 Solar radiation of 1000 W/m2 is incident on a grey opaque surface with an emissivity of 0.4 and emissive power (black body) of 400 W/m2. The radiosity of the surface will be 850 W/m2 760 W/m2 940 W/m2 670 W/m2