A food manufacturer uses infrared radiation to cook products on a production line. A hospital uses ultraviolet radiation to disinfect drinking water supplied to patients. Explain one use of each type of radiation and describe one hazard associated with each type of radiation.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
Infrared radiation is used to cook food on the production line by heating the food molecules, which increases their kinetic energy and causes cooking.
Infrared radiation can cause skin burns if the skin is exposed to high intensity IR.
Ultraviolet radiation is used to disinfect drinking water by breaking down the DNA of microorganisms, making them unable to reproduce.
Ultraviolet radiation can damage surface cells and the eyes, potentially leading to skin cancer or eye conditions.
Infrared radiation can cause skin burns if the skin is exposed to high intensity IR.
Ultraviolet radiation is used to disinfect drinking water by breaking down the DNA of microorganisms, making them unable to reproduce.
Ultraviolet radiation can damage surface cells and the eyes, potentially leading to skin cancer or eye conditions.
Examiner tips
- Use the exact terminology: infrared for cooking, ultraviolet for disinfection. Include a clear hazard for each: skin burns for IR, cellular damage/eye harm for UV. Keep each point brief and to the point to fit the 4‑mark structure.
Common mistakes
- Confusing UV with visible light or IR with visible light. Failing to mention the specific hazard (e.g., skin burns for IR, eye damage for UV). Using vague phrases like "danger" instead of the required hazard description.
Mark scheme (4 marks)
- Infrared use: infrared radiation is used for cooking food (or thermal imaging / short range communications)
- Infrared hazard: infrared radiation can cause skin burns
- Ultraviolet use: ultraviolet radiation is used to disinfect water (or in fluorescent/energy-efficient lamps / security marking)
- Ultraviolet hazard: ultraviolet radiation can cause damage to surface cells and eyes, which can lead to skin cancer or eye conditions
Key terms in this question
infrared radiation · ultraviolet · hazard
Related
- All Edexcel GCSE Physics (1PH0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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