Two spheres of the same material have radii 1 m and 4 m, temperature 4000K and 2000K respectively. Then the ratio of energy radiated per second by the first sphere as compared to that by the second is

Options

A. `1 : 1`
B. `16 : 1`
C. `4 : 1`
D. `1 : 9`

Answer

A

Explanation

`(E_(1))/(E_(2))=(A_(1)T_(1)^(4))/(A_(2)T_(2)^(4))=(R_(1)^(2)T_(1)^(4))/(R_(2)^(2)T_(2)^(4))=(1^(2)xx4000^(4))/(4^(2)xx2000^(4))=(16)/(16)=1`