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

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 of a black body at a temperature of $6000 \, K$. The maximum intensity of radiation is emitted at a wavelength of $4800 \, \mathring{A}$. If the temperature of the Sun decreases from $6000 \, K$ to $3000 \, K$,then at what wavelength (in $\mathring{A}$) will the maximum intensity of radiation be emitted?

If the temperature of the sun becomes twice its present temperature,then

The Sun emits light with a maximum wavelength of $510 \, nm$,while another star $X$ emits light with a maximum wavelength of $350 \, nm$. What is the ratio of the surface temperature of the Sun to that of star $X$?

The law used in the measurement of the temperature of stars is .........