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PET scanning past paper questions

A2 Physics 9702 · Medical physics. 1 understand that a tracer is a substance containing radioactive nuclei that can be introduced into the body and is then absorbed by the tissue being studied 2 recall that a tracer that decays by β+ decay is used in positron emission tomography (PET scanning) 3 understand that annihilation occurs when a particle interacts with its antiparticle and that mass–energy and momentum are conserved in the process 4 explain that, in PET scanning, positrons emitted by the decay of the tracer annihilate when they interact with electrons in the tissue, producing a pair of gamma-ray photons travelling in opposite directions 5 calculate the energy of the gamma-ray photons emitted during the annihilation of an electron-positron pair 6 understand that the gamma-ray photons from an annihilation event travel outside the body and can be detected, and an image of the tracer concentration in the tissue can be created by processing the arrival times of the gamma-ray photons

In Cambridge A Level A2 Physics 9702, PET scanning came up in 11 of the 42 papers on Paperstreak, for about 6 marks a paper when it does. It last came up in May/June 2025.

Often set with Radioactive decay, Wave-particle duality, Coulomb's law, Centripetal acceleration.

12 questions, newest first

  1. 9702/41/M/J/25 Question 8 parts (c) (d(i)) (d(ii)) (d(iii)) (d(iv)) (d(v)) · 10 marks
  2. 9702/43/M/J/25 Question 2 part (b(i)) · 1 mark
  3. 9702/43/M/J/25 Question 8 parts (c) (d(i)) (d(ii)) (d(iii)) (d(iv)) (d(v)) · 10 marks
  4. 9702/42/F/M/25 Question 9 parts (e(i)) (e(ii)) · 2 marks
  5. 9702/41/O/N/24 Question 9 parts (b(i)) (b(ii)) · 5 marks
  6. 9702/43/O/N/24 Question 9 parts (a(i)) (b(i)) (b(ii)) · 6 marks
  7. 9702/42/O/N/23 Question 9 parts (a(i)) (a(ii)) (b(i)) (b(ii)) · 7 marks
  8. 9702/42/O/N/22 Question 10 · 9 marks
  9. 9702/42/M/J/22 Question 2 parts (c(i)) (c(ii)) · 4 marks
  10. 9702/42/F/M/22 Question 11 parts (a) (b(i)) (b(ii)) (c(i)) (d) · 7 marks
  11. 9702/41/M/J/20 Question 11 parts (a(i)) (b) · 4 marks
  12. 9702/43/M/J/20 Question 11 · 6 marks

More in Medical physics: Production and use of ultrasound, Production and use of X-rays.

Questions and mark schemes from Cambridge International past papers. Paperstreak isn't affiliated with Cambridge.