If the absorption and reflection coefficients of a surface of a body are $0.4$ and $0.6$ respectively,then

If $E$ is the total energy emitted by a body at temperature $T \ K$ and $E_{max}$ is the maximum energy emitted by it at the same temperature,then:

Good absorbers of heat are

$Assertion :$ $A$ body that is a good radiator is also a good absorber of radiation at a given wavelength.
$Reason :$ According to Kirchhoff's law,the absorptivity of a body is equal to its emissivity at a given wavelength.

$A$ thermopile bolometer is used to detect:

Surface temperature of the sun is of the order of $K$.