126. The antiparticle of the electron is the:
- proton
- positron
- neutron
- neutrino
Answer: B) positron
Explanation: Charge +e, mass 9.11 10^-31 kg. SLO P-11-F-09 · Understanding
MCQs / Physics / Nuclear and Particle Physics
Nuclear and Particle Physics MCQs — Physics (page 6)
330 multiple-choice questions on Nuclear and Particle Physics from Physics, each with the correct answer and, where available, a teacher's explanation. Read through them to revise the chapter, then practise the same questions one by one to test yourself.
127. A single photon cannot be produced by annihilation of a particle pair at rest because:
- mass would increase
- energy would not be conserved
- charge would not be conserved
- momentum would not be conserved
Answer: D) momentum would not be conserved
Explanation: Total momentum is zero. SLO P-11-F-28 · Understanding
128. The equation for beta^+ decay of a proton (in a nucleus) is:
- n to p + e^+ + nue
- p to n + e^+
- p to n + e^- + barnue
- p to n + e^+ + nue
Answer: D) p to n + e^+ + nue
Explanation: Happens inside proton-rich nuclei. SLO P-11-F-10 · Knowledge
129. According to the Standard Model, every subatomic particle has:
- a corresponding antiparticle
- no antiparticle
- two antiparticles
- an antiparticle only if charged
Answer: A) a corresponding antiparticle
Explanation: Matter–antimatter symmetry. SLO P-11-F-19 · Understanding
130. Alpha particles from a particular nuclide have:
- discrete (definite) energies
- zero energy
- random energies
- a continuous range of energies
Answer: A) discrete (definite) energies
Explanation: Two-body decay shares energy in a fixed way. SLO P-11-F-11 · Understanding
131. A proton is accelerated through a p.d. of 1 10^6 V. The kinetic energy it gains is:
- 3.2 10^-13 J
- 1.6 10^-12 J
- 1.6 10^-13 J
- 8 10^-14 J
Answer: C) 1.6 10^-13 J
Explanation: KE = eV = 1.6 10^-19 1 10^6 = 1.6 10^-13 J. SLO P-11-F-23 · Understanding
132. Nucleons are classified as baryons because they contain:
- two quarks
- no quarks
- three quarks
- one quark and an antiquark
Answer: C) three quarks
Explanation: Baryon = three quarks. SLO P-11-F-20 · Understanding
133. Which statement about the quark change in beta decay is correct?
- Quarks are emitted from the nucleus
- Only the flavour of one quark changes
- Quarks turn into electrons directly without any boson
- All three quarks change
Answer: B) Only the flavour of one quark changes
Explanation: Weak flavour change. SLO P-11-F-15 · Knowledge
134. An antibaryon consists of:
- a quark and an antiquark
- three antiquarks
- leptons
- three quarks
Answer: B) three antiquarks
Explanation: e.g. the antiproton. SLO P-11-F-14 · Knowledge
135. Antimatter is used in medicine in:
- X-ray films
- ultrasound
- MRI only
- PET scans (positron emission tomography)
Answer: D) PET scans (positron emission tomography)
Explanation: Positrons annihilate with electrons. SLO P-11-F-24 · Understanding
136. A baryon consists of:
- three quarks
- an electron and a neutrino
- two quarks
- one quark and one antiquark
Answer: A) three quarks
Explanation: e.g. protons and neutrons. SLO P-11-F-14 · Knowledge
137. The antiparticle of the electron neutrino is the:
- electron antineutrino
- positron
- photon
- muon
Answer: A) electron antineutrino
Explanation: barnue. SLO P-11-F-16 · Knowledge
138. During beta decay, the number of quarks in the nucleon:
- stays at three
- becomes zero
- increases to four
- decreases to two
Answer: A) stays at three
Explanation: Only one quark changes flavour. SLO P-11-F-15 · Knowledge
139. In ^94 Be + ^42 He to ^126 C + X, X is:
- a gamma ray
- a neutron ^10 n
- a positron
- a proton
Answer: B) a neutron ^10 n
Explanation: Chadwick's discovery of the neutron (1932). SLO P-11-F-07 · Knowledge
140. Small differences in behaviour between matter and antimatter are called:
- CP violation
- Lenz's law
- Hooke's law
- Ohm's law
Answer: A) CP violation
Explanation: Observed in some particle decays. SLO P-11-F-27 · Understanding
141. Hadrons differ from leptons because hadrons:
- never decay
- are made of quarks and feel the strong force
- are fundamental
- have no mass
Answer: B) are made of quarks and feel the strong force
Explanation: Composite. SLO P-11-F-21 · Knowledge
142. Neutrinos and antineutrinos are classified as:
- quarks
- baryons
- mesons
- leptons
Answer: D) leptons
Explanation: Fundamental particles. SLO P-11-F-10 · Knowledge
143. A nucleus of ^73 Li contains how many up quarks?
- 14
- 11
- 10
- 7
Answer: C) 10
Explanation: 3 protons × 2 + 4 neutrons × 1 = 10. SLO P-11-F-20 · Understanding
144. An antiproton consists of:
- barubardbard
- udd
- barubarubard
- uud
Answer: C) barubarubard
Explanation: Antiquarks of the proton's quarks. SLO P-11-F-13 · Understanding
145. The pi^0 meson is made of:
- ubaru or dbard
- uud
- udd
- ubard
Answer: A) ubaru or dbard
Explanation: Neutral pion. SLO P-11-F-21 · Knowledge
146. Most of the mass of a proton actually comes from:
- the Higgs mass of its quarks alone
- the energy of the strong interactions among quarks and gluons
- electrons
- neutrinos
Answer: B) the energy of the strong interactions among quarks and gluons
Explanation: Quark masses are small. SLO P-11-F-18 · Knowledge
147. If future experiments found a large difference between hydrogen and antihydrogen spectra, it would:
- stop all research
- confirm all current theories exactly
- challenge fundamental symmetry principles
- prove nothing
Answer: C) challenge fundamental symmetry principles
Explanation: Major discovery. SLO P-11-F-27 · Understanding
148. Most of the matter in the observable universe is:
- ordinary matter (not antimatter)
- half matter and half antimatter
- antimatter
- photons only
Answer: A) ordinary matter (not antimatter)
Explanation: Matter dominates. SLO P-11-F-26 · Knowledge
149. Two positrons placed close together will:
- exert no force
- attract each other
- annihilate each other
- repel each other
Answer: D) repel each other
Explanation: Like charges repel. SLO P-11-F-25 · Understanding
150. The antiproton has:
- twice the proton's charge
- the mass of a proton and a negative charge
- no charge
- the mass of an electron and a positive charge
Answer: B) the mass of a proton and a negative charge
Explanation: Antiparticle of the proton. SLO P-11-F-09 · Understanding
Practise Nuclear and Particle Physics MCQs
More Physics chapters
- Physical Quantities and Measurement MCQs
- Motion MCQs
- Vectors MCQs
- Electricity MCQs
- Kinematics and Projectile Motion MCQs
- Circular and Rotational Motion MCQs
- Momentum and Collisions MCQs
- Deformation of Solids MCQs
- Work and Energy MCQs
- Fluid Statics and Dynamics MCQs
- Kinetic Theory and First Law of Thermodynamics MCQs
- Heat Engines, Second Law and Entropy MCQs