Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Astrophysics
156 practice questions
Topics covered
Practice questions
51–60 of 78 · Easy
Question 51
1 mark · Easy
Answer and check →Which of these best describes the main sequence stage of a star's life?
- A.The star is unstable and changes rapidly.
- B.The star's forces are balanced and it fuses hydrogen in its core.
- C.Fusion reactions have stopped and the star is collapsing.
- D.The star is a cloud of dust and gas.
Question 52
4 marks · Easy
Answer and see the solution →(a)[1 mark]State one difference between the life cycle of a star with a mass similar to the Sun and that of a much more massive star at the end of their lives.
(b)[3 marks]The star Betelgeuse will become a supernova. Explain why only some stars end their life as supernovae, and what happens to the material left behind after the explosion.
Question 53
4 marks · Easy
Answer and see the solution →A student observes two stars in the night sky: Star X is a red star, and Star Y is a blue star. Both are located in the same galaxy.
(a)[2 marks]State which star has the higher surface temperature. Explain your answer.
(b)[2 marks]Stars go through several stages in their life cycle. Name two stages a star like our Sun will go through after its main sequence period.
Question 54
4 marks · Easy
Answer and see the solution →The Hertzsprung-Russell (HR) diagram shows the relationship between a star’s brightness and its surface temperature. The position of a star on the diagram can be used to learn about its properties.
(a)[2 marks]What information about a star can scientists gain from knowing its position on the HR diagram? Give two points.
(b)[2 marks]State the region you would expect to find our Sun during the main stable period of its life.
Question 55
1 mark · Easy
Answer and see the solution →State what is meant by red-shift in the context of galaxies.
Question 56
1 mark · Easy
Answer and check →Which observation provides evidence that the universe is expanding?
- A.Red-shift of light from distant galaxies
- B.Bright flashes from supernovae
- C.Blue-shift in all nearby stars
- D.Regular brightness of the Sun
Question 57
1 mark · Easy
Answer and see the solution →State what the Doppler effect tells astronomers about distant galaxies.
Question 58
2 marks · Easy
Answer and see the solution →A galaxy is observed with its spectral lines shifted towards longer wavelengths.
(a)[1 mark]What is this effect called?
(b)[1 mark]What does this tell us about the motion of the galaxy relative to Earth?
Question 59
1 mark · Easy
Answer and see the solution →Name the scientist who first described the Doppler effect.
Question 60
2 marks · Easy
Answer and see the solution →Explain how observing red-shifted galaxies supports the idea that the universe is expanding.