Particles and Radiation Practice Questions
A-Levels · A-Level Physics · 148 free MCQs with instant results and detailed explanations.
148
Total
47
Easy
78
Medium
23
Hard
Start Practicing Particles and Radiation
Take a timed quiz or customize your practice session
Sample Questions from Particles and Radiation
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the charge of a proton?
A.
+1 elementary charge
B.
0 elementary charge
C.
-1 elementary charge
D.
2 elementary charges
Show Answer & Explanation
Correct Answer: A
A proton carries a positive charge of +1 elementary charge, which is fundamental in defining the atomic structure.
Q2
Easy
Which of the following particles has the least mass?
A.
Electron
B.
Proton
C.
Neutron
D.
Alpha particle
Show Answer & Explanation
Correct Answer: A
Electrons have significantly less mass than protons and neutrons, making them the lightest among these particles.
Q3
Easy
What type of radiation is emitted during the decay of a radioactive substance when an alpha particle is released?
A.
Alpha radiation
B.
Beta radiation
C.
Gamma radiation
D.
X-rays
Show Answer & Explanation
Correct Answer: A
The emission of an alpha particle during radioactive decay is classified as alpha radiation, which consists of helium nuclei.
Q4
Medium
What is the minimum energy required to create an electron-positron pair from a photon?
A.
1.022 MeV
B.
0.511 MeV
C.
1 MeV
D.
2 MeV
Show Answer & Explanation
Correct Answer: A
To create an electron-positron pair, the photon must have at least the combined rest mass energy of the two particles, which is 2 x 0.511 MeV = 1.022 MeV.
Q5
Medium
In a nuclear reaction, a neutron is absorbed by a nucleus, resulting in the emission of a beta particle. What type of reaction is this?
A.
Alpha decay
B.
Beta decay
C.
Gamma decay
D.
Neutron capture
Show Answer & Explanation
Correct Answer: B
When a neutron is absorbed, a proton is often produced, leading to the emission of a beta particle (an electron). This process is characteristic of beta decay.
Q6
Medium
A particle moves at relativistic speeds, close to the speed of light. How does its mass change according to the theory of relativity?
A.
Mass decreases as speed increases
B.
Mass remains constant
C.
Mass increases as speed increases
D.
Mass fluctuates randomly
Show Answer & Explanation
Correct Answer: C
According to the theory of relativity, as a particle approaches the speed of light, its relativistic mass increases, leading to greater inertial resistance.
Q7
Medium
Which of the following correctly describes the interaction of a photon with a material to produce photoelectric effect?
A.
Photon collides elastically with an electron.
B.
Photon transfers all its energy to an electron.
C.
Photon is absorbed without energy transfer.
D.
Photon scatters off an electron with no energy loss.
Show Answer & Explanation
Correct Answer: B
In the photoelectric effect, a photon transfers all its energy to an electron, allowing the electron to escape from the material if the energy exceeds the work function.
Q8
Hard
A proton and an alpha particle are both accelerated through the same potential difference of 1000 V. What is the ratio of their kinetic energies after acceleration?
A.
1:4
B.
1:2
C.
1:1
D.
1:3
Show Answer & Explanation
Correct Answer: A
The kinetic energy gained by a charged particle when accelerated through a potential difference is given by KE = qV, where q is the charge and V is the potential difference. The charge of a proton is +e and the charge of an alpha particle (which has 2 protons and 2 neutrons) is +2e. Therefore, KE_proton = e * 1000 and KE_alpha = 2e * 1000. The ratio KE_proton:KE_alpha = (e * 1000):(2e * 1000) = 1:2. However, since alpha particle has double the mass (4u as it contains 2 protons and 2 neutrons) compared to a proton (1u), we need to relate the kinetic energy with mass to get the ratio of their energies, hence the final ratio will simplify to 1:4.
Q9
Hard
A beam of alpha particles is aimed at a thin gold foil. If the scattering angle of one of the alpha particles is observed to be 180 degrees, what does this imply about the interaction between the alpha particle and the gold nucleus?
A.
The alpha particle penetrated the nucleus.
B.
The alpha particle was deflected by the electron cloud.
C.
The alpha particle experienced a direct collision with the nucleus.
D.
The alpha particle passed by without any interaction.
Show Answer & Explanation
Correct Answer: C
An alpha particle scattering at an angle of 180 degrees indicates a head-on collision with the nucleus. In such a collision, the alpha particle is repelled back due to the strong nuclear force acting between the positively charged alpha particle and the positively charged gold nucleus. This interaction shows that there is a significant presence of mass concentrated in the nucleus, which can cause such deflections.
Q10
Hard
A proton and an alpha particle are both accelerated through the same potential difference. Which of the following statements about their kinetic energies after acceleration is correct?
A.
The kinetic energy of the alpha particle is four times that of the proton.
B.
The kinetic energy of the proton is twice that of the alpha particle.
C.
Both particles have the same kinetic energy.
D.
The kinetic energy of the alpha particle is twice that of the proton.
Show Answer & Explanation
Correct Answer: A
The kinetic energy gained by a charged particle when accelerated through a potential difference (V) is given by KE = qV. The charge of the alpha particle (2e) is twice that of the proton (1e), and it also has a mass that is four times that of the proton. Therefore, the kinetic energy of the alpha particle, which is proportional to the charge, is four times that of the proton after acceleration through the same potential difference.
Showing 10 of 148 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 148 Questions →Particles and Radiation — A-Levels A-Level Physics Practice Questions Online
This page contains 148 practice MCQs for the chapter Particles and Radiation in A-Levels A-Level Physics. The questions are organized by difficulty — 47 easy, 78 medium, 23 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.