There is a black spot on a body. If the body is heated and carried into a dark room,then it glows more than the rest of the body. This can be explained on the basis of:

Heat energy is incident on the surface of a material at the rate of $1000 \ J \ min^{-1}$. If the coefficient of absorption is $0.8$ and the coefficient of reflection is $0.1$,then the amount of heat energy transmitted through the material in $5$ minutes is: (in $J$)

Three identical metal spheres (of same surface area) have red,black,and white colors and they are heated up to the same temperature. They are allowed to cool. Arrange them from maximum rate of cooling to minimum rate of cooling.

$Assertion$ : The Earth without an atmosphere would be inhospitably cold.
$Reason$ : All heat would escape in the absence of an atmosphere.

$A$ body has a black spot on it. When the body is heated and taken into a dark room,the black spot glows more brightly. This can be explained by which of the following?

Heat radiations propagate with the speed of