A thin copper rod of uniform cross section A square metres and of length L metres has a spherical metal sphere of radius r metre at tis one end symmetrically attached to the copper rod. The thermal conductivity of copper is K and the emissivity of the spherical surface of the sphere is `epsi`.The free end of the copper rod is maintained at the temperature T kelving by supplying thermal energy from a P watt source. Steady state conditions are allowed ot be established while the rod is properly insulated aginst heat loss from its lateral surface. Surroundings are at `0^@C` Stefan's constant`=sigma W//m^(2)K^(4)`.
If the metal sphere attached at the end of the copper rod is made of brass, whose thermal conductivity is `K_b lt K`, then which of the following statements is true?

Options

A. The temperature of the sphere will, under steady state conditions, continue to be `T_B`
B. The power that will be radiated out from the sphere will still be `P_S`.
C. It will take smaller time for steady state conditions to be reached
D. The rate of thermal energy transmitted across the copper rod, under steady state, will reduced.

Answer

B

Explanation

The temperature `T_S` will change to a new value. The transmitted thermal energy will be the same.