At a temperature of $2000 \; K$,the maximum energy of a black body is emitted at a wavelength of $14 \; \mu m$. When its temperature is reduced to $1000 \; K$,the wavelength corresponding to the maximum energy emitted is ....... $\mu m$.

Which one of the following is the $\nu_{m}-T$ graph for a perfectly black body? Here, $\nu_{m}$ is the frequency of radiation with maximum intensity and $T$ is the absolute temperature.

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 $b = 2.88 \times 10^{-3} \, mK$.

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 was cooled down from $6000\,K$ to $3000\,K$,then the peak intensity would occur at a wavelength of ........ $\mathring{A}$.

The temperature of a furnace is $200\,^{\circ}C$. In its spectrum,the maximum intensity is obtained at about $400\,\mathring{A}$. If the maximum intensity is at $200\,\mathring{A}$,calculate the temperature of the furnace in $^{\circ}C$. ......... $^{\circ}C$

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