An astronomer compares three spectral lines measured in a laboratory with the same lines in light from four galaxies.
| Source | Wavelength of line 1 in nm | Wavelength of line 2 in nm | Wavelength of line 3 in nm |
|---|---|---|---|
| Laboratory | 410 | 434 | 486 |
| Galaxy J | 414 | 438 | 491 |
| Galaxy K | 406 | 430 | 481 |
| Galaxy L | 410 | 434 | 491 |
| Galaxy M | 414 | 434 | 486 |
Which statement explains why the light from one of the galaxies is red-shifted?
Galaxy J, because all three spectral lines have longer wavelengths than the corresponding laboratory lines
Galaxy K, because all three spectral lines have shorter wavelengths than the corresponding laboratory lines
Galaxy L, because only the spectral line with the longest wavelength has increased in wavelength
Galaxy M, because only the spectral line with the shortest wavelength has increased in wavelength
79 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.