The spectrum of black body radiation is a ...... .

The intensity of direct sunlight on a surface normal to the rays is $I_0$. What is the intensity of direct sunlight on a surface,whose normal makes an angle of $60^{\circ}$ with the rays of the sun?

The sun radiates electromagnetic energy at the rate of $3.9 \times 10^{26} \ W$. Its radius is $6.96 \times 10^8 \ m$. The intensity of sunlight at the solar surface will be (in $W/m^2$):

The absorption coefficient value of a perfect black body is

What are heat rays?

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