For a perfectly black body,the coefficient of emission (emissivity) is:

Shown below are the black body radiation curves at temperatures $T_1$ and $T_2$ $(T_2 > T_1)$. Which of the following plots is correct?

The black lines in the solar spectrum during a solar eclipse can be explained by

Consider black body radiation in a cubical box at absolute temperature $T$. If the length of each side of the box is doubled and the temperature of the walls of the box and that of the radiation is halved, then the total energy

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 $J$)

If $150 \,J$ of energy is incident on an area of $2 \,m^{2}$. If $Q_{r}=15 \,J$ and the coefficient of absorption is $0.6$,then the amount of energy transmitted is: (in $\,J$)