Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
THE DOPPLER EFFECT
16 practice questions
Practice questions
1–8 of 8 · 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.