Question

The temperature of two bodies $A$ and $B$ are respectively, $727?C$ and $327?C$. The ratio $H_A : H_B$ of the rates of heat radiated by them is

• A. 727 : 327
• B. 5:03
• C. 25:09:00
• D. 625 : 81

Answer 1

Answer: (D)

625 : 81

Answer 2

$\frac{H_{A}}{H_{B}} =\frac{\left(727 + 273\right)^{4}}{\left(327 +273\right)^{4}}$
$= \left(\frac{1000}{600}\right)^{4} = \frac{5 \times5\times5\times5}{3\times3\times3\times3} = \frac{625}{81}$