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 $W/m^2$):

Which of the following is the correct device for the detection of thermal radiation?

The graph shown in the adjacent diagram represents the variation of temperature $(T)$ of two bodies,$x$ and $y$,having the same surface area,with time $(t)$ due to the emission of radiation. Find the correct relation between their emissivities $(e)$ and absorptive powers $(a)$.

The surface of a thermos flask is kept shiny because:

In the rainy season,on a clear night,the black seat of a bicycle becomes wet because:

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