Question

If temperature of a black body increases from $7^{o}Cto{287}^{o}C$ then the rate of energy radiation increases by

• A.
• B. 16
• C. 4
• D. 2

Answer 1

The correct option is B

16

For a block body rate of energy $\frac{Q}{t}=P=A\sigma T^4$
$\Rightarrow P\propto T^4\Rightarrow \frac{T_1}{T_2}=\{\frac{(273+7)}{(273+287)}{\}}^4=\frac{1}{16}$