iGCSE Physics (0625) 5.2.1 Detection of radioactivity Paper 1-2023,2024&2025

Question

The diagram shows a radioactivity experiment.

                                       

When a piece of paper is used as the absorber, the count rate drops to the background count rate.

Which radiation is the source emitting?

A \alpha-radiation only

B \beta-radiation only

C \gamma-radiation only

D \alpha-radiation, \beta-radiation and \gamma-radiation

Answer/Explanation

Ans: A

Question

The graph shows how the count rate from a radioactive sample changes with time.

                                                       

What is the half-life for this sample?

A 90 s

B 120 s

C 200 s

D 400 s

Answer/Explanation

Ans: B

Question

Which statement about α -particles and \gamma-rays is correct?

  1. \alpha-particles are a form of electromagnetic radiation.

  2. \alpha-particles penetrate materials more easily than \gamma-rays.

  3. The emission of an \alpha-particle produces a nucleus of a different element.

  4. \gamma-rays are more ionising than \alpha-particles.

Answer/Explanation

Ans: C

Question

The graph shows the activity of a radioactive source over a period of time.

What is the half-life of the source?

A 1.0 minute

B 2.0 minutes

C 2.5 minutes

D 4.0 minutes

Answer/Explanation

Ans: B

Question

A student measures the level of radiation emitted by a radioactive sample.

                         

The table shows the readings she records on the counter over a short period of time.

counter reading

/ counts per minute

106

96

98

100

The sample is removed and the counter then shows a background radiation reading of 4 counts per minute.

What is the best estimate for the average count rate due to the radioactive sample?

A 96 counts per minute                    B 98 counts per minute                    C 100 counts per minute                      D 104 counts per minute

Answer/Explanation

Ans: A

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