A Geiger-Müller tube and counter are used to measure the radiation level in a laboratory. Even when no radioactive source is placed near the detector, a low count rate is still recorded. This is due to background radiation.
Which of the following does not contribute to this background radiation?
cosmic rays from space
radioactive radon gas from the ground
Wi-Fi and mobile phone signals
medical procedures such as X-rays
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.