The radiant energy from the Sun incident normally at the surface of earth is `20kcal//m^(2)` min What would have been the radiant energy incident normally on the earth if the sun had a temperature twice of the present one ? .

Options

A. `40kcal//(m^(2)-min)`
B. `80kcal//(m^(2)-min)`
C. `160kCal//(m^(2)-min)`
D. `320Kcal(m^(2)-min)`

Answer

D

Explanation

`E=sigmaT^(4)rArr(E_(1))/(E_(2))=((T_(1))/(T_(2)))^(4)`