The maximum energy in thermal radiation from a source occurs at the wavelength $4000 \mathring A$. The effective temperature of the source is ....... $K$.

Use the formula $\lambda_{m} T = 0.29 \; cm \cdot K$ to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?

The colour of a star is an indication of its

Star $S_1$ emits maximum radiation of wavelength $420 \, nm$ and the star $S_2$ emits maximum radiation of wavelength $560 \, nm$. What is the ratio of the temperature of $S_1$ and $S_2$?

$Assertion :$ For higher temperature, the peak emission wavelength of a blackbody shifts to lower wavelengths.
$Reason :$ Peak emission wavelength of a blackbody is proportional to the fourth power of temperature.

Solar radiation emitted by the Sun resembles that of a black body at a temperature of $6000 \, K$. The maximum intensity of radiation is emitted at a wavelength of $4800 \, \mathring{A}$. If the temperature of the Sun decreases from $6000 \, K$ to $3000 \, K$,then at what wavelength (in $\mathring{A}$) will the maximum intensity of radiation be emitted?