Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Cosmology
37 practice questions
Topics covered
Practice questions
1–10 of 19 · Normal
Question 1
4 marks · Normal
Answer and see the solution →When astronomers observe a distant galaxy through a telescope, they analyse its light spectrum to investigate its movement.
(a)[1 mark]State what is meant by red-shift in the context of light from galaxies.
(b)[2 marks]Explain what the observation of red-shifted light tells astronomers about the motion of distant galaxies.
(c)[1 mark]Describe how the size of the observed red-shift relates to the distance of a galaxy from Earth.
Question 2
3 marks · Normal
Answer and see the solution →Explain how the observation of red-shifted light from distant galaxies provides evidence for the Big Bang theory.
Question 3
1 mark · Normal
Answer and check →Which of the following is direct evidence that the universe is expanding?
- A.The cosmic microwave background radiation
- B.Observing galaxies with a blue-shift
- C.Red-shift in the light from distant galaxies
- D.The formation of supernovae
Question 4
2 marks · Normal
Answer and see the solution →A student incorrectly states that the blue-shift of galaxy light proves the universe is expanding. Explain why this statement is incorrect.
Question 5
4 marks · Normal
Answer and see the solution →The diagram shows lines on the spectrum of light from two galaxies, Q and R, at different observed wavelengths.
(a)[2 marks]State which galaxy, Q or R, is moving away from Earth faster. Justify your answer using the spectrum diagram.
(b)[2 marks]The normal wavelength of a particular line in a laboratory is 590 nm. For Galaxy Q, this line is observed at 594 nm. For Galaxy R, it is observed at 600 nm. Calculate the change in wavelength () for both galaxies.
Question 6
3 marks · Normal
Answer and see the solution →A sodium lamp on Earth emits a spectral line with a wavelength of 589 nm. The same line from a distant galaxy is observed at 600 nm.
Calculate the red-shift () of light from this galaxy. Use:\n\[ z = \frac{\Delta \lambda}{\lambda_0} \] where is the original wavelength.
Question 7
3 marks · Normal
Answer and see the solution →Describe two scientific arguments that support the Big Bang theory, other than red-shift.
Question 8
3 marks · Normal
Answer and see the solution →A table below shows observed red-shift (z) values for different galaxies at increasing distances from Earth.
Red-shift and distance for several galaxies Galaxy Distance (million light-years) Red-shift (z) A 100 0.005 B 200 0.010 C 400 0.020 D 600 0.030 (a)[2 marks]Describe the relationship between galaxy distance and red-shift shown in the table.
(b)[1 mark]Suggest what this relationship supports about the universe.
Question 9
4 marks · Normal
Answer and see the solution →A scientist studies the light emitted from a nearby galaxy and observes that absorption lines have shifted compared to those from our Sun.
(a)What is this phenomenon, and what does it tell us about the motion of the galaxy relative to Earth?
(b)[2 marks]Explain why the absorption lines move towards the red end of the spectrum.
(b)[2 marks]Explain why the absorption lines move towards the red end of the spectrum.
Question 10
3 marks · Normal
Answer and see the solution →Light from a distant galaxy shows an absorption line at a wavelength of 650 nm, while the same line from our Sun is at 520 nm. Calculate the speed at which the galaxy is moving relative to Earth. (Speed of light = )