Uses and risks of radiationIB MYP Physics: Mind map

Exam questions on Uses and risks of radiation

1. A hospital in Cape Town treats a patient who has a tumour using a beam of gamma rays. The beam is aimed at the tumour from several different directions around the patient's body.
   Explain why gamma rays can kill cancer cells.2 marks
2. A paper mill in Finland makes a continuous sheet of paper that must have a constant thickness. A radioactive source on one side of the moving sheet sends radiation through the paper to a detector on the other side. A computer monitors the count rate at the detector and adjusts the rollers that press the paper.
   Explain why a source with a long half-life is chosen for this job.2 marks
3. A hospital radiographer works with a gamma source for several hours each day. She follows three safety rules: she keeps the source in a lead container when it is not in use, she stays as far from the source as she can, and she limits the time she spends near it. She also wears a film badge.
   Explain how each of her three rules reduces the radiation dose she receives.3 marks