A and B are two isolated spheres kept in close proximity so that they can exchange energy by radiation as shown in the following figure. The two spheres ,have identical physical dimension, but the surface of A behaves like a perfectly black body while the surface of B reflects 20% of all the radiations it receives. They are isolated from all other sources of radiation.

Options

A. If they are in thermal equilibrium and exchange equal amounts of radiation per second, then they will be at same absoulte temperature, `T_(A) = T_(B)`.
B. If they are in thermal equilibrium and exchange equal amounts of radiation per second, the `T_(A) = ( 0.8)^(1//4) T_(B)`.
C. If they ar enot in thermal equilibrium and are each at t =0 at the same temperature `T_(A) = T_(B) = T`, then the sphere A will loss thermal energy and B gain thermal energy.
D. If they are not in thermal equilibrium and are each at t=0 at the same temperature `T_(A) = T_(B) =T`, then the sphere A will gain thermal energy and B lose thermal energy.

Answer

A