Two solid spheres of radii `R_(1)` and `R_(2)` are made of same material and have similar surface. The spheres are raised to the same temperature and then allowed to cool under identical conditions. Assuming spheres to be perfect conductors of heat, their initial ratio of rates of loss of heat is:

Options

A. `R_(1)^(2)//R_(2)^(2)`
B. `R_(1)//R_(2)`
C. `R_(2)//R_(1)`
D. `R_(2)^(2)//R_(1)^(2)`

Answer

A

Explanation

Initial rate of loss of heat `=(sigma T^(4) xx A_(1)xx e)/(sigma T^(4)xxA_(2) xx e)=(R_(1)^(2))/(R_(2)^(2))`