Two spheres A and B have radius but the heat capacity of A is greater than that of B. The surfaces of both are painted black. They are heated to the same temperature and allowed to cool. Then initially

Options

A. A cools faster than B
B. Both A and B cool at the same rate
C. At any temperature the ratio of their rates of cooling is a constant
D. B cools faster than A

Answer

C, D

Explanation

Rate ofcooling = Radiation rate/heat capacity. As the heat capacity ofboth bodies are constant and radiation rate is same due to same surface area and same temperature, the ratio ofrate ofcolling of both will be a constant.