A black body at a temperature of $127°C$ radiates heat at the rate of $1 cal/cm^2 × sec$. At a temperature of $527°C$ the rate of heat radiation from the body in ($cal/cm^2 × sec$) will be
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(a) $\frac{{{Q_2}}}{{{Q_1}}} = \frac{{T_2^4}}{{T_1^4}} = {\left( {\frac{{273 + 527}}{{273 + 127}}} \right)^4} = {\left( {\frac{{800}}{{400}}} \right)^4}$
==>${Q_2} = 16\frac{{cal}}{{c{m^2} \times s}}$
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