An automated quality control system uses a radioactive source to monitor the density of a flowing polymer. A safety engineer carries out test measurements with various absorbers placed between the source and a Geiger-Müller detector. The background count rate in the laboratory is determined to be $(cpm)15\text{ counts per minute (cpm)}$ .

The recorded count rates are:

Source with no absorber: $cpm1450\text{ cpm}$
Source with a thin sheet of cardboard: $cpm320\text{ cpm}$
Source with a 3 mm aluminium plate: $cpm318\text{ cpm}$
Source with a 50 mm lead block: $cpm18\text{ cpm}$

Which types of radiation are emitted by the radioactive source?

Alpha particles and gamma rays only

Alpha and beta particles only

Alpha particles, beta particles, and gamma rays

The recorded count rates are:

Source with no absorber: $cpm1450\text{ cpm}$
Source with a thin sheet of cardboard: $cpm320\text{ cpm}$
Source with a 3 mm aluminium plate: $cpm318\text{ cpm}$
Source with a 50 mm lead block: $cpm18\text{ cpm}$

Which types of radiation are emitted by the radioactive source?

Alpha particles and gamma rays only

Alpha and beta particles only

Alpha particles, beta particles, and gamma rays

Radioactive emissions

Question 7

Markscheme

Radioactive emissions

Question 7

Markscheme

Radioactive emissions

Question 7

Radioactive emissions Questions

Radioactive emissions

Question 7

Radioactive emissions Questions