An experimenter sets up the following apparatus, in air, to discover whether a radioactive source is emitting alpha-particles. sheet of paper radioactive source radiation detector to counting device 30 cm The experimenter moves the paper between the source and the detector. There is no difference in the count-rate. Why is this?

5054_w07_qp_1

MCQ

2007

Paper 1, Variant 0

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A student investigates a radioactive source that emits only alpha-particles. Without any source nearby, the detector shows a low reading. The source and thick cardboard are placed near the detector, as shown...

5054_w10_qp_11

MCQ

2010

Paper 1, Variant 1

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A student investigates a radioactive source that emits only alpha-particles. Without any source nearby, the detector shows a low reading. The source and thick cardboard are placed near the detector, as shown...

5054_w10_qp_12

MCQ

2010

Paper 1, Variant 2

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In a laboratory experiment, particles from a radioactive source are deviated by a magnetic field and reach a detector. 10 cm magnetic field into the paper radioactive source detector Which particles are deviated and reach the detector?

5054_w11_qp_11

MCQ

2011

Paper 1, Variant 1

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In a laboratory experiment, particles from a radioactive source are deviated by a magnetic field and reach a detector. 10 cm magnetic field into the paper radioactive source detector Which particles are deviated and reach the detector?

5054_w11_qp_12

MCQ

2011

Paper 1, Variant 2

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The diagram shows the radioactive emissions that pass through a piece of plastic and a piece of metal of the same thickness. alpha beta gamma detector plastic metal alpha beta gamma detector Which types of radioactive emission can distinguish between the plastic and the metal?

5054_w12_qp_12

MCQ

2012

Paper 1, Variant 2

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The filament in a cathode-ray oscilloscope (c.r.o.) emits charged particles by thermionic emission. State the name of the charged particles that are emitted. Explain what causes the particles to be emitted. State why there must be a vacuum in the c.r.o. tube. The particles emitted have a charge of size 1.6 × 10–19 C and carry a current of 5.6 × 10–3 A between the filament and the screen of the c.r.o. Calculate the number of particles that strike the screen every second. number =

5054_w12_qp_22

THEORY

2012

Paper 2, Variant 2

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A radioactive sample emits only beta-particles and gamma-rays. Describe, with the aid of a labelled diagram, an experiment that shows that the sample does not emit alpha-particles. State two safety precautions that must be taken when working with the radioactive sample. 1. 2.

5054_w13_qp_21

THEORY

2013

Paper 2, Variant 1

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A smoke detector containing an alpha-particle source is fixed to the ceiling in a room. The alpha-particles ionise the air between two metal plates so that a battery produces a current between the plates. If smoke enters the detector, it reduces the current between the plates and an alarm sounds. shows the arrangement. ceiling ionised air alpha-particle source to alarm circuit metal plates A technician removes the source from the smoke detector and measures the count rate of the source. Suggest two precautions that the technician should take when working with the source. 1. 2. The technician measures the count rate, in counts / s, five times. On each occasion, the arrangement of the equipment is the same. The values obtained are: 81 77 80 83 and 79. Suggest why the values are different. Radioactive sources that emit beta-particles or gamma-rays are not used in smoke detectors. State and explain two reasons for this. 1. 2. .

5054_w13_qp_22

THEORY

2013

Paper 2, Variant 2

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People working with radioactive materials use a photographic film badge covered in paper. The badge is used to monitor the level of their exposure to radiation. Which radiation is detected?

5054_w14_qp_12

MCQ

2014

Paper 1, Variant 2

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