A star cluster in our galaxy is moving towards the Earth. An astronomer compares the absorption lines in light from the cluster with the same lines produced in a laboratory.
How do the lines from the cluster compare with the laboratory lines?
They have a longer observed wavelength and a higher observed frequency.
They have a shorter observed wavelength and a lower observed frequency.
They have a longer observed wavelength and a lower observed frequency.
They have a shorter observed wavelength and a higher observed frequency.
94 exam-style questions on Edexcel GCSE Physics 7.2 The Universe and red-shift, covering 7.2.1 Big Bang and Steady State theories, 7.2.2 Evidence for the Big Bang, 7.2.3 The Doppler effect and red-shift, 7.2.4 Red-shift as evidence for an expanding Universe, and 7.2.5 The CMB and the accepted model. Each one has a worked solution and a mark scheme showing where the marks go.