Physics Year 10 Quiz

During the quality control of paper production, the thickness is assessed using β–particles. If the paper is excessively thin, more β–particles will reach the detector. A source of γ–particles is not utilized for this measurement because γ–particles would (a)  

• pass through the paper without interaction.

• be harmful to the environment.

• alter the properties of the paper.

• create a significant radiation hazard.

A radiation detector is positioned near a source of γ–rays. As lead sheets of increasing thickness are placed between the source and the detector, a sheet that is 5.0 cm thick is eventually used. The reading on the detector decreases but does not reach zero. What could be the reason for this?

• Some of the γ–rays may scatter off the lead sheets.

• The detector is not sensitive enough.

• There is always some background radiation present.

• The lead sheet cannot completely block all γ–rays.

The equation describes the decay of an isotope of uranium U to an isotope of thorium Th, accompanied by the release of particle Y. 92 U 238 → 90 Th 234 + Y What is particle Y?

• –1 e 0

• 1 H 1

• 2 He 4

• 0 n 1

A researcher measures the decay of a different radioactive isotope over a period of six minutes. The background radiation is recorded at 25 counts per minute. Based on the data collected, what is the half-life of this isotope?

• 0.50 minutes

• 2.0 minutes

• 3.0 minutes

• 6.0 minutes

A radioactive isotope has a half-life of 5.0 years. If a sample initially contains 48 million radioactive nuclei, how many nuclei will remain undecayed after 15 years?

• 6.0 million

• 12.0 million

• 24.0 million

• 36.0 million

When β–particles traverse the magnetic field between two charged plates, they are deflected in a specific direction. How do X–rays behave when they pass through the same magnetic field? (a)  

• They are deflected in the same direction as β–particles.

• They are deflected in the opposite direction.

• They are not deflected at all.

• They follow a curved path.

Static electricity can build up on various materials, leading to unwanted attraction or repulsion. To effectively discharge this static electricity, a certain type of radiation is utilized; refer to the accompanying diagram. Which type of radiation is best suited for discharging static electricity?

• ⍺–particle

• Β–particle

• ɣ–ray

• neutron

Which of the following is a natural source of radiation found in soil?

• radon gas

• medical imaging

• nuclear reactors

• industrial radiography

What type of radiation is commonly produced when a nucleus undergoes beta decay after being impacted by a neutron?

• ⍺–particles

• Β–particles

• ɣ–rays

• Neutrons

A scientist measures the activity of a radioactive sample and finds it to be 1000 counts per minute. After 10 years, the activity is measured again and found to be 125 counts per minute. What is the half-life of this radioactive material?

• 2.5 years

• 20.0 years

• 10.0 years

• 5.0 years