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Q.
If a black body emits $0.5$ joules of energy per second when it is at $27^\circ\,C$ , then the amount of energy emitted by it when it is at $627\,{}^\circ$C will be
According to Stefan 's law
$E \propto T^{4}$
$\frac{E_{1}}{E_{2}}=\left[\frac{T_{1}}{T_{2}}\right]^{4}$
$\frac{E_{1}}{0.5}=\left[\frac{273+627}{273+27}\right]^{4}$
$E_{1}=0.5\left(\frac{900}{300}\right)^{4}$
$\Rightarrow \,\,\,\,E_{1}=40.5\, J$