Ultraviolet radiation from the Sun can damage skin.
The Table shows the maximum time that unprotected skin can be exposed to sunlight before damage occurs, for different values of the UV index.
Table
| UV index | Maximum exposure time in minutes |
|---|---|
| 2 | 60 |
| 4 | 30 |
| 6 | 20 |
| 8 | 15 |
| 10 | 12 |
Describe the relationship between the UV index and the maximum exposure time.
Predict the maximum exposure time when the UV index is 12.
Show how you obtained your answer.
A sunscreen allows skin to be exposed for 30 times longer than unprotected skin.
A person wearing this sunscreen spends 4 hours in sunlight when the UV index is 8.
Determine whether the person's skin is protected for the whole time.
Explain why repeated exposure to ultraviolet radiation increases the risk of skin cancer.
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.