$A$ 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

Experimental investigations show that the intensity of solar radiation is maximum for a wavelength $480 \, nm$ in the visible region. Estimate the surface temperature of the sun. Given Wien's constant $b = 2.88 \times 10^{-3} \, mK$.

The maximum wavelength of radiations emitted at $900\,K$ is $4\,\mu m$. What will be the maximum wavelength of radiations emitted at $1200\,K$ (in $,\mu m$)?

In a certain planetary system,it is observed that one of the celestial bodies having a surface temperature of $200 \; K$,emits radiation of maximum intensity near the wavelength $12 \; \mu m$. The surface temperature (in $K$) of a nearby star which emits light of maximum intensity at a wavelength $\lambda = 4800 \; \mathring A$ is

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

If at temperature $T_1 = 1000 \ K,$ the wavelength is $1.4 \times 10^{-6} \ m,$ then at what temperature in $K$ will the wavelength be $2.8 \times 10^{-6} \ m$?