Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Astrophysics
156 practice questions
Topics covered
Practice questions
91–100 of 156
Question 91
2 marks · Easy
Answer and see the solution →Information on the surface temperature and absolute magnitude of three stars. Star Surface Temperature (K) Absolute Magnitude Alpha 6,000 +5 Beta 20,000 -5 Gamma 3,500 -1 Based on the data above, which star is the brightest and which is the coolest?
Question 92
2 marks · Easy
Answer and see the solution →Explain why a star changes colour as it evolves from a red giant into a white dwarf.
Question 93
3 marks · Easy
Answer and see the solution →(a)[2 marks]Draw a simple labelled sequence showing the main stages in the life of a star similar to our Sun, from nebula to black dwarf.
(b)[1 mark]State the stage at which fusion of helium nuclei occurs.
Question 94
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 95
2 marks · Normal
Answer and see the solution →State the name of the process that causes hydrogen nuclei to join together at the start of a star's life. What form of energy is released during this process?
Question 96
3 marks · Normal
Answer and see the solution →A star forms from a cloud of gas with an initial temperature of K. Due to gravitational compression, its temperature increases by a factor of . Calculate the final temperature of the star once it reaches its main sequence stage.
Question 97
4 marks · Normal
Answer and see the solution →The table below shows the absolute magnitudes and surface temperatures of three stars:
Properties of different stars Star Absolute Magnitude Surface Temperature (K) Alpha 3.5 6,000 Beta −5.0 18,000 Gamma 12.0 3,500 (a)[1 mark]Which star is the brightest? Explain your answer.
(b)[1 mark]Which of the stars is likely to be a white dwarf? Give a reason for your choice.
(c)[2 marks]State what the star Beta's temperature suggests about its stage in its lifecycle.
Question 98
4 marks · Normal
Answer and see the solution →The diagram below represents simplified stages in the life of a star with a mass much greater than our Sun.
Stages in the lifecycle of a massive star (a)[2 marks]Describe what happens to the star as it moves from red supergiant (C) to supernova (D).
(b)[2 marks]Explain the main difference between the neutron star and black hole outcomes (E, F).
Question 99
3 marks · Normal
Answer and see the solution →Explain why gravitational forces become dominant over outward pressure at the end of the main sequence stage of a star similar to our Sun.
Question 100
1 mark · Normal
Answer and check →Which part of the Hertzsprung-Russell (HR) diagram represents the main sequence?
- A.A diagonal band from high temperature/bright to low temperature/dim.
- B.A cluster at the top right corner.
- C.A horizontal line at the bottom.
- D.A vertical line at the left edge.