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 $^{\circ}C$. ......... $^{\circ}C$

The plots of intensity $(I)$ versus wavelength $(\lambda)$ for three black bodies at temperatures $T_1, T_2$ and $T_3$ respectively are as shown. Their temperatures are such that:

The graph of relative intensity versus wavelength for three perfectly black bodies at temperatures $T_1, T_2,$ and $T_3$ is shown below. The relationship between their temperatures is:

The maximum wavelength of radiation emitted by a star is $289.8 \ nm$. The intensity of radiation for the star is (Given: Stefan's constant $\sigma = 5.67 \times 10^{-8} \ W \ m^{-2} \ K^{-4}$,Wien's constant $b = 2898 \ \mu m \ K$)

On observing light from three different stars $P, Q$ and $R$, it was found that the intensity of violet colour is maximum in the spectrum of $P$, the intensity of green colour is maximum in the spectrum of $R$, and the intensity of red colour is maximum in the spectrum of $Q$. If $T_P, T_Q$ and $T_R$ are the respective absolute temperatures of $P, Q$ and $R$, then it can be concluded from the above observations that:

If a black wire of platinum is heated, its colour first appears red, then yellow, and finally white. This can be understood on the basis of: