$A$ thermos flask is polished well.

The Sun emits radiation in all directions. The Earth receives approximately $1.4 \ kW/m^2$ of radiation per second. The distance between the Sun and the Earth is $1.5 \times 10^{11} \ m$. How much mass does the Sun lose per day? $(1 \ \text{day} = 86400 \ s)$

Which of the following statements is true for a perfectly black body?

The absorption coefficient value of a perfect black body is

We consider the radiation emitted by the human body. Which of the following statements is true?

$A$ body,which emits radiations of all possible wavelengths,is known as