A black body at a temperature of `227^(@)C` radiates heat energy at the rate of 5 cal/`cm^(2)`-sec. At a temperature of `727^(@)C`, the rate of heat radiated per unit area in cal/`cm^(2)`-sec will be

Options

A. 80
B. 160
C. 250
D. 500

Answer

A

Explanation

`(E_(2))/(E_(1))=((T_(2))/(T_(1)))^(4)`
`(E_(2))/(E_(1))=((273+727)/(273+227))`
`(E_(2))/(5)=((1000)^(4))/((5000)^(4))=16`
`E_(2)=80cal//cm^(2)`