Free Nuclear Physics MCQs with Answers

• A. Through direct collision
• B. Through electrostatic repulsion
• C. Through electrostatic attraction
• D. All of the above

Explanation: A beta particle (an electron or positron) can ionize atoms through multiple electrostatic interactions.

• A. Uranium and Polonium
• B. Radium and Uranium
• C. Polonium and Radium
• D. Uranium and Plutonium

Explanation: In 1898, Marie and Pierre Curie conducted pioneering research on radioactivity.

• A. α. rays
• B. γ. rays
• C. β. rays
• D. All of the above have the same speed

Explanation: Gamma (γ) rays are a form of electromagnetic radiation (photons). As such, they travel at the speed of light (c) in a vacuum, which is the…

• A. Antiproton
• B. Gamma ray
• C. Positron
• D. Photon

Explanation: A positron is the antimatter counterpart of an electron. It has the exact same mass as an electron but carries a positive charge of equal…

• A. α. rays
• B. X. rays
• C. β. rays
• D. Neutron

Explanation: Because neutrons are uncharged, they do not interact with matter via electrostatic forces and penetrate much deeper than charged particles…

• A. 1H1 and 2H1
• B. 30H15 and 30Si14
• C. 12C6 and 16O8
• D. 40Cl and 40Ar
• E. Both B and D

Explanation: Isobars have the same mass number but different atomic numbers. Pairs B and D meet this condition.

• A. Rectilinear
• B. Zigzag or erratic
• C. Curved
• D. Elliptical

Explanation: Beta particles are much less massive than alpha particles and are easily deflected by collisions and interactions with atomic electrons in…

• A. Smaller ionizing power
• B. Same ionizing power
• C. Energy not being conserved
• D. Neither greater nor smaller ionizing power

Explanation: Penetrating power is inversely related to ionizing power. Alpha particles interact strongly with matter, losing their energy quickly over…

• A. Trajectory
• B. Firing level
• C. Range
• D. Limit

Explanation: The range of a radioactive particle is the characteristic distance it can travel through a specific medium before it loses all its kinetic…

• A. Zinc Sulphide
• B. Sodium iodide
• C. Barium Platinocyanide
• D. All of the above

Explanation: Fluorescence or scintillation is emission of light by substance when it absorbs ionizing radiation.

• A. 10 times more
• B. 100 times less
• C. 100 times more
• D. 10 times less

Explanation: Beta particles are smaller and have a single charge, causing them to interact less frequently with matter than the larger, doubly.

• A. The emission of a β particle increases the mass number "A" by one and decreases the atomic number "Z" by one
• B. The disintegrating element merely ejects atomic electrons
• C. The emission of alpha particles decreases the mass number "A" by four and decreases the atomic number "Z" by two
• D. The nucleus always remains unaffected

Explanation: Alpha decay is a common process in the uranium series. Each time an alpha particle (2He4) is emitted, the parent nucleus loses 2 protons…

• A. Energy absorbed = 5.70 MeV
• B. Energy released = 5.70 MeV
• C. Energy absorbed = 6.70 MeV
• D. Energy released = 6.70 MeV

Explanation: Negative Q-value means the reaction is endothermic (absorbs energy). Calculation: Δm = 9.0122 + 4.0026 − (12 + 2×1.0087) = 0.0061 u…

• A. 1
• B. No change will be observed
• C. 2
• D. 4

Explanation: Gamma decay does not change the charge or mass number. Beta (β⁻) decay involves a neutron becoming a proton, which increases the atomic…

• A. The rate of disintegration is directly proportional to the number of atoms present in the sample at that instant.
• B. Equal fractions disintegrate in equal intervals of time.
• C. A radioactive sample takes an infinite time to disintegrate completely.
• D. All of the above.

Explanation: All three statements are fundamental principles of radioactive decay. The rate is proportional to the number of nuclei (A), which leads to…

• A. The same mass
• B. The same charge
• C. The same speed
• D. The same deflection

Explanation: Beta particles are either electrons or positrons. All electrons have the exact same rest mass, and all positrons have the exact same rest…

• A. N₀
• B. N₀/4
• C. N₀/2
• D. 3N₀/4

Explanation: After one half-life, half of the initial number of nuclei (N₀/2) remain. After a second half. life, half of that amount will remain.

• A. An atom
• B. An element
• C. A molecule
• D. A nucleus

Explanation: Gamma decay is a nuclear process. It occurs when a nucleus is in a high energy (excited) state, often after a previous alpha or beta…

• A. 2.5 mg
• B. 0.625 mg
• C. 1.25 mg
• D. 0.3125 mg

Explanation: The amount remaining after n half. lives is the initial amount divided by 2ⁿ.

• A. Absorb low amount of energy
• B. Absorb high amount of energy
• C. Reduce their binding energy per nucleon
• D. Increase their binding energy per nucleon

Explanation: Maximum binding energy is achieved around Z = 50 (Iron is close to peak at Z = 56).