When working in a laboratory with sources of ionizing radiation, safety regulations aim to minimize the radiation dose received by scientists.
Which of the following actions does not reduce a scientist's exposure or dose when handling an external radioactive source?
Selecting a source with a longer half-life but the same initial activity.
Using long-handled tongs to maximize the distance from the source.
Limiting the total time spent near the radioactive source.
Placing a lead shield of appropriate thickness between the source and the scientist.
42 exam-style questions on CIE IGCSE Physics 5.2.5 Effects of ionising radiation and safety precautions. Each one has a worked solution and a mark scheme showing where the marks go.