May/June 2026 Paper 41

State Wien's displacement law.

The Sun has a radius of $6.96\times 10^8\text{ m}$ and a surface temperature of $5770\text{ K}$. The Earth is at a distance of $1.52\times 10^{11}\text{ m}$ from the Sun. Calculate the luminosity of the Sun.

Determine the radiant flux intensity at the Earth of radiation emitted by the Sun. Give a unit with your answer.

Star X has a wavelength of maximum emission of $0.581{\lambda }_{\text{s}}$, where ${\lambda }_{\text{s}}$ is the wavelength of maximum emission from the Sun. Calculate the surface temperature of star X.