Question

The effective area of a black body is 0.1 $m^2$ and its temperature is 1000 K. The amount of radiations emitted by it per min is -

• A. 1.34 k-cal
• B. 81 k-cal
• C. 5.63 k-cal
• D. 1.34 k-J.

Answer 1

Answer: (B)

81 k-cal

$\begin{array}{c}\frac{d\varnothing }{dt}=A6T{Y}^4\\ =81kcal\end{array}$