Some sources of background radiation are natural and others are due to human activity.
Which of the following background radiation sources is due to human activity?
cosmic rays from outer space
radioactive fallout from historic nuclear weapons testing
gamma rays emitted from granite buildings
radon gas seeping from the ground
44 exam-style questions on CIE IGCSE Physics 5.2.1 Background radiation and measuring count rate. Each one has a worked solution and a mark scheme showing where the marks go.