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Home · IGCSE 0625 · Nuclear physics · Safety precautions · Practice
Core · Practice questions · Safety precautions

Time, distance, shielding.

Six original Cambridge-style questions on radiation safety: the dangers, the three ways to reduce dose, safe handling and storage, and monitoring.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
What the examiner wants

Lower the dose, every way you can.

01
Recall
[1 mark]

State why ionising radiation can be harmful to people.

  • It can damage or kill living cells (and can cause cancer). ✓
02
Recall
[3 marks]

State the three main ways a worker can reduce the dose they receive from a radioactive source.

  • Spend less time near the source. ✓
  • Stay a greater distance away. ✓
  • Use shielding such as lead or concrete. ✓
03
Application
[2 marks]

Explain why a radioactive source is picked up with long tongs rather than with bare hands.

  • The tongs keep the source further from the body. ✓
  • The dose falls with distance, so the hands receive much less radiation. ✓
04
Recall
[2 marks]

State how radioactive sources should be stored when not in use, and why.

  • In a clearly labelled lead-lined box. ✓
  • The lead absorbs the radiation, so people nearby receive a low dose. ✓
05
Application
[1 mark]

People who work with radiation often wear a small badge. State what this badge is for.

  • To monitor (measure) the total dose of radiation they have received. ✓
06
Application
[3 marks]

A radiographer takes X-ray images of patients all day. Describe three precautions they should take to keep their own dose low.

  • Stand behind a shielded screen or wall during the exposure. ✓
  • Keep a distance from the beam and the patient when the X-ray is taken. ✓
  • Limit the time of exposure, and wear a monitoring badge. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.