A textile laboratory measures the visible-light count rate from three dye samples, first with an ultraviolet lamp switched off and then with it switched on.
| Dye sample | UV lamp off (counts/s) | UV lamp on (counts/s) |
|---|---|---|
| P | 12 | 14 |
| Q | 11 | 86 |
| R | 48 | 49 |
Explain which dye sample is most suitable for producing visible light under ultraviolet radiation. Use the readings and describe how the dye interacts with the radiation.
104 exam-style questions on Edexcel GCSE Physics 5.4 Uses and dangers of EM radiation, covering 5.4.1 Dangers of electromagnetic radiation, 5.4.2 Uses of electromagnetic radiation, 5.4.3 Radio waves and oscillations in circuits, and 5.4.4 Changes in atoms and nuclei generating radiation. Each one has a worked solution and a mark scheme showing where the marks go.