$A$ total radiation of $400 \ J$ is incident on a body. If $20\%$ of the radiation is reflected and $120 \ J$ is absorbed,find the percentage of the transmittive power.

$A$ body is said to be opaque to the radiation if ($a$,$r$,and $t$ are the coefficients of absorption,reflection,and transmission,respectively).

The rate of radiation of energy from a hot object is maximum,if its surface is ...........

When the bulb is switched on,what happens to the level of alcohol on the $X$ side?

At a high temperature,a body emits radiation of wavelengths $\lambda_1, \lambda_2, \lambda_3,$ and $\lambda_4$ only. At a lower temperature,which of the following wavelengths will it absorb?

Distribution of energy in the spectrum of a black body can be correctly represented by