A Geiger counter is placed near a radioactive source and different materials are placed between the source and the Geiger counter - AQA - A-Level Physics - Question 27 - 2017 - Paper 2
Question 27
A Geiger counter is placed near a radioactive source and different materials are placed between the source and the Geiger counter.
The results of the tests are show... show full transcript
Worked Solution & Example Answer:A Geiger counter is placed near a radioactive source and different materials are placed between the source and the Geiger counter - AQA - A-Level Physics - Question 27 - 2017 - Paper 2
Step 1
Evaluate the results with 'None' material
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Answer
The count rate is 1000 counts per second, indicating that the source emits radiation that can penetrate the materials used.
Step 2
Evaluate the results with 'Paper'
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Answer
The count rate remains 1000 counts per second, suggesting that the radiation must be alpha radiation, as it can penetrate paper.
Step 3
Evaluate the results with 'Aluminium foil'
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Answer
The count rate drops to 250 counts per second. This indicates that some radiation is blocked by the foil, suggesting that beta radiation is also emitted.
Step 4
Evaluate the results with 'Thick steel'
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Answer
The count rate further decreases to 50 counts per second, confirming that the radiation is strongly shielded, which suggests the presence of gamma radiation, as it requires dense materials to significantly reduce its intensity.
Step 5
Conclusion
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Answer
The source must emit eta and eta (beta) as well as extγ (gamma) radiation since both particle and electromagnetic radiation are indicated by the decreasing counts through the materials.
