Practise

Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

TopicSkillDifficulty

12 questions

SA-9702-MP3-0031 markL1 FoundationCalculatorTracers

The radioactive tracer used in PET scanning decays by

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SA-9702-MP3-0041 markL1 FoundationCalculatorAnnihilation

When a positron and an electron annihilate at rest, two photons are emitted in opposite directions because

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SA-9702-MP3-0061 markL1 FoundationCalculatorTracers

A radioactive tracer is

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SA-9702-MP3-0081 markL1 FoundationCalculatorAnnihilation

State the energy of each annihilation photon in MeV.

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SA-9702-MP3-0121 markL1 FoundationCalculatorTracers

Compared with an X-ray image, a PET scan mainly shows

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SA-9702-MP3-0012 marksL2 StandardCalculatorAnnihilation

An electron and a positron at rest annihilate. Calculate the energy of each photon produced, in units of

10^{-14}

J. (

m_e=9.11\times10^{-31}

kg;

c=3.00\times10^8

m s⁻¹)

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SA-9702-MP3-0021 markL2 StandardCalculatorAnnihilation

Calculate the wavelength of a

8.2\times10^{-14}

J annihilation photon, in units of

10^{-12}

m. (

h=6.63\times10^{-34}

J s;

c=3.00\times10^8

m s⁻¹)

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SA-9702-MP3-0052 marksL2 StandardCalculatorAnnihilation

Photons from an annihilation arrive at opposite detectors with a time difference of

0.40

ns. Calculate how far from the midpoint between the detectors the event occurred, in cm.

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SA-9702-MP3-0071 markL2 StandardCalculatorTracers

PET tracers are chosen to have short half-lives so that

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SA-9702-MP3-0091 markL2 StandardCalculatorTracers

Fluorine-18 has a half-life of

110

minutes. A dose has activity

400

MBq at injection. Calculate its activity

330

minutes later.

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SA-9702-MP3-0101 markL2 StandardCalculatorAnnihilation

In a PET scanner, an annihilation event is recorded when

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SA-9702-MP3-0113 marksL3 ExamCalculatorAnnihilation

A positron with kinetic energy

0.25

MeV annihilates with an electron at rest. Calculate the total energy of the two photons produced, in MeV.

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