The light from a distant galaxy is observed to be red-shifted.
What happens to the observed frequency of this light?
The observed frequency increases
The observed frequency stays the same
The observed frequency falls to zero
The observed frequency decreases
41 exam-style questions on AQA GCSE Physics 8.2 Red-shift, covering 8.2 Red-shift. Each one has a worked solution and a mark scheme showing where the marks go.