CAPE Physics Unit 2 · 2010 · Paper 1 · Question Q37

An experiment to investigate the absorption of \gamma-rays in air using ^{60}\text{Co} as the source is illustrated in the diagram below. x is the distance between the source and region in the G-M tube where ionisation of the gas occurs. The distance x, between the ^{60}\text{Co} source and the G-M tube was varied, and the corresponding values obtained for the count rate, R, were recorded. Which of the following graphs BEST represents the results of this experiment?

1. (A)[diagram option — open in Quelpr]
2. (B)[diagram option — open in Quelpr]
3. (C)[diagram option — open in Quelpr]
4. (D)[diagram option — open in Quelpr]

This question uses a figure or table from the paper — you'll see it when you practise.