If a black body emits 0.5 joules of energy per second when it is at `27^(@)`C , then the amount of energy emitted by it it when it is at `627^(@)C` will be

Options

A. `13.5 J`
B. `135 J`
C. `40.5 J`
D. `162 J`

Answer

C

Explanation

The energy emitted by a black body per second is given Stefan's law `E=sigmaT^(4)`.
`therefore(E')/(E)sigma*((273+627)^(4))/((273+27)^(4))=sigma*((900K)^(4))/((300K)^(4))`
`rArrE'=0.5xx((900)^(4))/((300)^(4))=0.5xx81=40.5J`.