Physics (AS & A Level) · Oct / Nov 2017 · Paper 11 · Question 25

Light of a particular wavelength λs is emitted from the Sun. At any instant, a band of wavelengths ranging from less than λs to more than λs is observed on the Earth. This is caused by the Doppler effect. [diagram: Sun with arrows pointing right towards Earth, labelled NOT TO SCALE] What could be the explanation for this Doppler effect?

1. AThe Sun is moving at right-angles to a line joining the Sun and the Earth.
2. BThe Sun is moving away from the Earth.
3. CThe Sun is moving towards the Earth.
4. DThe Sun is rotating.

As printed in the paper