Astronomers compare the light from distant galaxies with the light from the Sun.
The dark lines in the spectrum of light from a distant galaxy are at longer wavelengths than the same dark lines in the spectrum of light from the Sun.
Name this effect.
State what has happened to the frequency of the light from the galaxy, compared with the light from the Sun.
The light from galaxy B shows a greater shift than the light from galaxy A.
Give two conclusions about galaxy B compared with galaxy A.
Explain how the shift in the light from distant galaxies is evidence that the universe is expanding.
50 exam-style questions on OCR GCSE Physics 8.3 Beyond Earth, covering 8.3.1 Red-shift and the expanding universe, 8.3.2 Evidence for the Big Bang model, 8.3.3 Formation of the Sun and stellar equilibrium, 8.3.4 Radiation emitted by hot bodies, 8.3.5 The solar system and satellites, 8.3.6 Gravity and circular orbits, 8.3.7 Orbital radius and orbital speed, 8.3.8 Radiation balance and the temperature of the Earth, and 8.3.9 Seismic waves and exploring hidden structures. Each one has a worked solution and a mark scheme showing where the marks go.