A worker carries out three tasks in a store containing a sealed gamma source. The maximum permitted total dose during the inspection is 80 μSv.
Dose equals dose rate multiplied by exposure time. The total dose is the sum of the doses received during all three tasks.
| Task | Dose rate in μSv per minute | Exposure time in minutes |
|---|---|---|
| 1 | 12 | 2.0 |
| 2 | 7 | 4.0 |
| 3 | 6 | to be determined |
The worker completes tasks 1 and 2. Calculate the greatest whole number of minutes the worker can spend on task 3 without exceeding the maximum permitted total dose.
Explain one change to the working arrangement that could allow the worker to spend longer on task 3 without exceeding the maximum permitted total dose.
104 exam-style questions on Edexcel GCSE Physics 5.4 Uses and dangers of EM radiation, covering 5.4.1 Dangers of electromagnetic radiation, 5.4.2 Uses of electromagnetic radiation, 5.4.3 Radio waves and oscillations in circuits, and 5.4.4 Changes in atoms and nuclei generating radiation. Each one has a worked solution and a mark scheme showing where the marks go.