GCSE Questions: Medical Physics
- scanning and therapy
Q2.
(a) The different sources of radiation to which we are exposed are shown in the pie chart. Some sources are natural and some artificial.
(i) Name one natural source of radiation shown in the pie chart.
Any one from: cosmic rays, rocks, food, air 
(1 mark)
(ii) Name one artificial source of radiation shown in the pie chart.
Any one from: medical, nuclear power stations, nuclear weapons testing, food
(1 mark)
(b) A radioactive source can give out three types of emission: alpha particles beta particles gamma radiation. The diagram shows the paths taken by the radiation emitted by two sources, X and Y.
What types of radiation are emitted by each of the sources?
X emits alpha
Y emits alpha, beta and gamma (must have all three for the mark)
(2 marks)
(c) The diagram shows a disposable syringe sealed inside a plastic bag.
After the bag has been sealed the syringe is sterilised using radiation.
State what type of radiation is used for this purpose and explain why the radiation can be used to sterilise the syringe.
Gamma radiation is used, It can penetrate (the plastic and the syring parts).
It kills bacteria or microbes or micro-organisms or viruses (not germs) on all parts of the instrument
(3 marks)
(Total 7 marks)
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But food cannot score in both (i) and (ii)
