Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature?

The intensity of radiation emitted by the sun has its maximum value at a wavelength of $510\;nm$ and that emitted by the north star has the maximum value at $350\;nm$. If these stars behave like black bodies,then the ratio of the surface temperature of the sun and north star is

$A$ black body radiates maximum energy at wavelength $\lambda$ and its emissive power is $E$. Now,due to a change in the temperature of that body,it radiates maximum energy at wavelength $\frac{2\lambda}{3}$. At that new temperature,the emissive power is:

Wien's constant is $2892 \times 10^{-6} \text{ m K}$ and the value of $\lambda_m$ from the moon is $14.46 \text{ microns}$. What is the surface temperature of the moon in $K$?

Two stars emit maximum radiation of wavelength $3600 \ \mathring{A}$ and $4800 \ \mathring{A}$ respectively. The ratio of 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 $b = 2898 \ \mu m \ K$)