Question

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

• A.
• B. 16
• C. 4
• D. 2

Answer 1

The correct option is B

16

$Forablockbodyrateofenergy\frac{Q}{t}=P=A\sigma T^4\Rightarrow P\alpha T^4\Rightarrow \frac{P_1}{P_2}={\left(\frac{T_1}{T_2}\right)}^4={\left\{\frac{(273+7)}{(273+287)}\right\}}^4=\frac{1}{16}$