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

$A$ body at $3000 \,K$ emits maximum energy at a wavelength of $9660 Å$. If the sun emits maximum energy at a wavelength of $4950 Å$, what would be the temperature of the sun (in $\,K$)?

$A$ black body has a maximum wavelength $\lambda_{m}$ at a temperature of $2000 \ K$. Its maximum wavelength at $3000 \ K$ will be:

$A$ piece of iron is heated in a flame. It first becomes dull red, then becomes reddish yellow, and finally turns to white hot. The correct explanation for the above observation is possible by using

For a perfectly black body,a graph is plotted between the frequency of radiation with maximum intensity $(v_m)$ and the absolute temperature $T$. Which of the following graphs is correct?

The colour of a shining bright star is an indication of its