Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature?

$A$ black body has a maximum wavelength of $\lambda_m$ at a temperature of $2000 \ K$. What will be the maximum wavelength at a temperature of $3000 \ K$?

Solar radiation emitted by the sun resembles that emitted by a black body at a temperature of $6000 \ K$. Maximum intensity is emitted at a wavelength of about $4800 \ \mathring{A}$. If the sun were to cool down from $6000 \ K$ to $3000 \ K$,then the peak intensity would occur at a wavelength of ....... $\mathring{A}$.

The colour of a star is an indication of its

On increasing the temperature of a substance gradually, which of the following colours will be noticed by you?

Which of the following is the $\nu_m - T$ graph for a perfectly black body? ($\nu_m$ = maximum frequency of radiation,$T$ = absolute temperature)