A student uses a Geiger-Müller counter to detect the radiation from a sample of uranium ore in a physics laboratory. The teacher explains that they must first measure and subtract the background radiation.
What is this background radiation?
ultraviolet light from the laboratory's ceiling lights
ionising radiation present in the laboratory when the uranium ore is not there
infrared radiation emitted by the student and the laboratory equipment
radio waves from nearby communication transmitters
484 exam-style questions on CIE IGCSE Physics 5.2 Radioactivity, covering 5.2.1 Background radiation and measuring count rate, 5.2.2a Alpha, beta and gamma emission, 5.2.2b Deflection and ionising effects of nuclear radiation, 5.2.3a Radioactive decay, 5.2.3b Effects of decay on the nucleus and decay equations, 5.2.4a Half-life, 5.2.4b Choosing isotopes for applications, and 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.