Question 10

10(a)(i)2 marks

State what is meant by the luminosity of a star.

State A short answer. No explanation is needed, and adding one cannot earn extra marks.

Your answer

Suggested time: 3 min

10(a)(ii)3 marks

Explain how a standard candle in a distant galaxy can be used to determine the distance of the galaxy from an observer.

Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.

Your answer

Suggested time: 5 min

10(b)(i)2 marks

The Sun has a radius of 6.96 × 10⁸ m and a surface temperature of 5780 K. Light from the Sun is observed to have a peak intensity at a wavelength of 501 nm.

Calculate the luminosity of the Sun. Give a unit with your answer.

Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.

Your answer

Suggested time: 3 min

10(b)(ii)2 marks

Light from the Sun, which has a surface temperature of 5780 K, is observed to have a peak intensity at a wavelength of 501 nm. Another star emits radiation that has a peak intensity at a wavelength of 624 nm.

Determine the surface temperature of this star.

Determine Work it out from what you are given or from the figure, and show how you got there.

Your answer

Suggested time: 3 min

9702/41/M/J/24Cambridge International AS & A Level Physics 9702 · May/June 2024 · Paper 4 variant 1 · sit the whole paper