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1. Which of the following is the weakest fundamental force in nature?
A. Gravitational Force
B. Weak Nuclear Force
C. Electromagnetic Force
D. Strong Nuclear Force
Answer: A. Gravitational Force
Explanation: Gravitational force is the weakest of all four fundamental forces, having a relative strength of 10⁻³⁹ compared to the strong nuclear force.
2. Which fundamental force operates over the strongest scale and binds protons and neutrons inside a nucleus?
A. Strong Nuclear Force
B. Electromagnetic Force
C. Gravitational Force
D. Weak Nuclear Force
Answer: A. Strong Nuclear Force
Explanation: The strong nuclear force is the strongest fundamental force in nature, holding nucleons together within nuclear dimensions (~10⁻¹⁵ m).
3. Who among the following discovered the electron?
A. J.J. Thomson
B. Ernest Rutherford
C. James Chadwick
D. Niels Bohr
Answer: A. J.J. Thomson
Explanation: J.J. Thomson discovered the electron in 1897 through his cathode ray tube experiments.
4. The discovery of the neutron is credited to
A. James Chadwick
B. J.J. Thomson
C. Ernest Rutherford
D. Albert Einstein
Answer: A. James Chadwick
Explanation: James Chadwick discovered the neutron in 1932 by bombarding beryllium with alpha particles.
5. The range of gravitational force is
A. Infinite
B. Very short (~10⁻¹⁵ m)
C. Short (~10⁻¹⁶ m)
D. Zero
Answer: A. Infinite
Explanation: Gravitational force obeys the inverse square law and extends up to an infinite range, dominating macroscopic astronomical interactions.
6. Which fundamental force is responsible for beta decay in radioactivity?
A. Weak Nuclear Force
B. Strong Nuclear Force
C. Gravitational Force
D. Electromagnetic Force
Answer: A. Weak Nuclear Force
Explanation: Weak nuclear force governs elementary particle interactions involved in radioactive decay, such as beta decay.
7. According to Einstein's mass-energy equivalence, the relation between energy E and mass m is
A. E = mc²
B. E = mc
C. E = m/c²
D. E = m²c
Answer: A. E = mc²
Explanation: Albert Einstein proposed the mass-energy conservation law represented by E = mc², where c is the speed of light in a vacuum.
8. Which of the following fundamental forces is strictly attractive in nature?
A. Gravitational Force
B. Electromagnetic Force
C. Weak Nuclear Force
D. None of these
Answer: A. Gravitational Force
Explanation: Gravitational force is always attractive, whereas electromagnetic force can be attractive or repulsive depending on the charges involved.
9. Who discovered the phenomenon of Raman Effect?
A. C.V. Raman
B. S.N. Bose
C. Homi J. Bhabha
D. M.N. Saha
Answer: A. C.V. Raman
Explanation: Sir C.V. Raman discovered the inelastic scattering of light, known as the Raman Effect, earning the Nobel Prize in Physics in 1930.
10. The exchange particle for electromagnetic force is
A. Photon
B. Graviton
C. Gluon
D. Boson
Answer: A. Photon
Explanation: Photons act as quantum field carriers (mediators) for electromagnetic interactions between charged particles.
11. Which law states that the total linear momentum of an isolated system remains constant?
A. Law of Conservation of Linear Momentum
B. Law of Conservation of Energy
C. Law of Conservation of Angular Momentum
D. Law of Conservation of Mass
Answer: A. Law of Conservation of Linear Momentum
Explanation: If no net external force acts on a system, its total linear momentum remains conserved.
12. Microscopic domain of physics deals with the study of
A. Atoms, nuclei, and elementary particles
B. Planets and stars
C. Terrestrial objects
D. Laboratory experiments at human scales
Answer: A. Atoms, nuclei, and elementary particles
Explanation: The microscopic domain includes subatomic phenomenon studied under quantum mechanics, whereas macroscopic physics deals with classical physics.
13. Mechanics, Electrodynamics, Optics, and Thermodynamics are branches of
A. Classical Physics
B. Quantum Physics
C. Nuclear Physics
D. Particle Physics
Answer: A. Classical Physics
Explanation: Classical physics mainly deals with macroscopic phenomena and includes branches like mechanics, electrodynamics, optics, and thermodynamics.
14. The ratio of the strength of strong nuclear force to gravitational force is of the order of
A. 10³⁹
B. 10²5
C. 10¹²
D. 10²
Answer: A. 10³⁹
Explanation: Gravitational force is extremely weak compared to strong nuclear force, with a relative ratio of roughly 1 : 10³⁹.
15. Cosmic ray cascades and quantum theory of radiation were significantly contributed to by Indian physicist
A. Homi J. Bhabha
B. Satyendra Nath Bose
C. J.C. Bose
D. S. Chandrasekhar
Answer: A. Homi J. Bhabha
Explanation: Dr. Homi J. Bhabha contributed pioneering work in cosmic ray research and theoretical nuclear physics in India.
16. The unified theory of electromagnetic and weak nuclear forces was proposed by
A. Abdus Salam, Sheldon Glashow, and Steven Weinberg
B. Isaac Newton and Galileo Galilei
C. James Clerk Maxwell
D. Albert Einstein
Answer: A. Abdus Salam, Sheldon Glashow, and Steven Weinberg
Explanation: Electroweak unification was achieved by Glashow, Salam, and Weinberg, earning them the 1979 Nobel Prize in Physics.
17. Electromagnetic force operates between
A. Charged particles
B. All massive bodies
C. Uncharged nucleons only
D. Neutrinos only
Answer: A. Charged particles
Explanation: Electromagnetic force acts specifically between charged particles in motion or at rest.
18. Who discovered the law of gravitation?
A. Isaac Newton
B. Johannes Kepler
C. Galileo Galilei
D. Michael Faraday
Answer: A. Isaac Newton
Explanation: Sir Isaac Newton formulated the Universal Law of Gravitation in 1687.
19. Which conservation law is a consequence of the homogeneity of time?
A. Conservation of Energy
B. Conservation of Linear Momentum
C. Conservation of Charge
D. Conservation of Angular Momentum
Answer: A. Conservation of Energy
Explanation: According to Noether's theorem, the symmetry corresponding to the homogeneity of time gives rise to the law of conservation of energy.
20. The fundamental force that does not require any intervening medium to act is
A. All fundamental forces
B. Gravitational force only
C. Electromagnetic force only
D. None of these
Answer: A. All fundamental forces
Explanation: Fundamental forces are non-contact field forces that operate across space without requiring a material medium.
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