Two sphere made of the same material have their radii in the ratio of `2 : 1`. What is the ratio of the radiant energy emitted per second by them if both of them are at the same temperature ?

Options

A. `4 : 1`
B. `1 : 4`
C. `2 : 1`
D. `1 : 2`

Answer

A

Explanation

`(d theta)/(dt)propA" "therefore(((d theta)/dt)_(1))/(((d theta)/dt)_(2))=(4piR_(1)^(2))/(4piR_(2)^(2))=4/1`