Physics · May / June 2023 · Paper 12 · Question 40

Four of the stages in the life cycle of a star, until it becomes a red giant, are shown. W Inward force of gravitational attraction is balanced by an outward force from its centre. X Internal gravitational collapse produces an increase in temperature. Y It expands. Z Most of the hydrogen has been converted to helium. In which order do these stages occur, starting with the earliest?

1. AW → X → Y → Z
2. BW → X → Z → Y
3. CX → W → Y → Z
4. DX → W → Z → Y

As printed in the paper