With no radioactive source present, a radiation detector is set to zero and switched on for 5 minutes. After this time, the counter displays:
1 2 5 \boxed{1}\;\boxed{2}\;\boxed{5} 125What radiation is the apparatus detecting?
Calculate the average count rate of this radiation in counts/min\text{counts/min}counts/min.
A source known to be highly radioactive is placed at a point 30 cm from the radiation detector. The counter is reset to zero and the count is taken again for 5 minutes. The counter now displays:
1 2 2 \boxed{1}\;\boxed{2}\;\boxed{2} 122State what type of radiation is being emitted by the source.
The source is moved to a position 3 cm from the detector. The counter is reset to zero and restarted. The counter reading after counting for 5 minutes is:
9 7 5 \boxed{9}\;\boxed{7}\;\boxed{5} 975Estimate the average count rate due to the radioactive source alone.
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.