Waves and Optics MCQs January 8, 2026July 12, 2024 by u930973931_answers 50 min Score: 0 Attempted: 0/50 Subscribe 1. What is the rest mass of a photon? (A) Zero (B) Infinite (C) 1 electron mass (D) Planck’s constant 2. Who proposed the theory of relativity? (A) Albert Einstein (B) Isaac Newton (C) Max Planck (D) Niels Bohr 3. What is the speed of light in a vacuum? (A) 3 × 10^7 m/s (B) 3 × 10^8 m/s (C) 3 × 10^9 m/s (D) 3 × 10^10 m/s 4. Which experiment provided direct evidence for the wave nature of electrons? (A) Double-slit experiment (B) Photoelectric effect (C) Compton effect (D) Davisson-Germer experiment 5. What is the wavelength of an electron with a kinetic energy of 100 eV? (A) 0.8 nm (B) 6.2 nm (C) 2.5 nm (D) 12.3 nm 6. Which particle is exchanged in the electromagnetic force? (A) Proton (B) Electron (C) Photon (D) Neutron 7. What is the Heisenberg Uncertainty Principle? (A) Exact position and momentum of a particle can be simultaneously known. (B) Quantum particles have both wave and particle properties. (C) The energy and time of a particle can be precisely measured. (D) There are limits to the precision with which pairs of properties of a particle can be known. 8. Who discovered the neutron? (A) James Chadwick (B) Niels Bohr (C) Ernest Rutherford (D) Werner Heisenberg 9. Which phenomenon proves the wave-particle duality of light? (A) Photoelectric effect (B) Double-slit experiment (C) Compton effect (D) Quantum tunneling 10. What is the minimum energy required to create a pair of particle-antiparticle? (A) Equal to the rest mass of the particle (B) Equal to the rest mass of the antiparticle (C) Half of the rest mass of the particle (D) Twice the rest mass of the particle 11. What is the energy equivalent of 1 atomic mass unit (amu)? (A) 9.11 × 10^-31 J (B) 1.67 × 10^-27 J (C) 1.49 × 10^-10 J (D) 1.49 × 10^-13 J 12. Which force is responsible for radioactive decay? (A) Weak nuclear force (B) Strong nuclear force (C) Electromagnetic force (D) Gravitational force 13. What is the name of the process by which a nucleus emits an alpha particle? (A) Fission (B) Fusion (C) Alpha decay (D) Beta decay 14. Which of the following particles has no electric charge? (A) Proton (B) Positron (C) Electron (D) Neutron 15. What happens to the mass of a nucleus during beta decay? (A) It increases (B) It decreases (C) It remains the same (D) It fluctuates 16. Which type of radiation is the most penetrating? (A) Alpha radiation (B) Beta radiation (C) Gamma radiation (D) Neutron radiation 17. What is the half-life of a radioactive substance? (A) The time it takes for the substance to become non-radioactive (B) The time it takes for half of the substance to decay (C) The time it takes for the substance to emit all its radiation (D) The time it takes for the substance to emit half its radiation 18. What is the mass number of an atom? (A) Number of protons (B) Number of neutrons (C) Number of electrons (D) Sum of protons and neutrons 19. Which particle has the same mass as an electron but opposite charge? (A) Positron (B) Neutron (C) Proton (D) Alpha particle 20. In a nuclear reactor, which process is used to release energy? (A) Fusion (B) Alpha decay (C) Fission (D) Beta decay 21. What is the name of the equation relating mass and energy, as proposed by Einstein? (A) Planck’s equation (B) E = mc^2 (C) Bohr’s equation (D) Maxwell’s equation 22. What is the energy of a photon with a wavelength of 500 nm? (A) 4.0 × 10^-19 J (B) 3.98 × 10^-20 J (C) 3.98 × 10^-19 J (D) 4.0 × 10^-20 J 23. What property of a wave corresponds to the loudness of sound? (A) Frequency (B) Wavelength (C) Velocity (D) Amplitude 24. What is the energy level of an electron in an atom related to? (A) Its mass (B) Its velocity (C) Its distance from the nucleus (D) Its potential energy 25. What is the name of the process where a nucleus captures an electron and converts it into a neutron? (A) Beta decay (B) Electron capture (C) Positron emission (D) Alpha decay 26. What is the name of the process where two nuclei combine to form a heavier nucleus? (A) Alpha decay (B) Fission (C) Fusion (D) Beta decay 27. What is the name of the device that detects and measures radioactivity? (A) Spectrometer (B) Geiger counter (C) Accelerometer (D) Refractometer 28. What is the energy of an electron in the first excited state of a hydrogen atom? (A) 1.51 eV (B) 3.4 eV (C) 13.6 eV (D) 0.85 eV 29. Which type of electromagnetic radiation has the highest energy? (A) Radio waves (B) Microwaves (C) Infrared (D) X-rays 30. Which phenomenon is explained by the wave nature of matter? (A) Photoelectric effect (B) Davisson-Germer experiment (C) Compton effect (D) Planck’s constant 31. What is the name of the force that holds the nucleus together? (A) Gravitational force (B) Electromagnetic force (C) Strong nuclear force (D) Weak nuclear force 32. What is the name of the process where a radioactive nucleus spontaneously emits an alpha particle? (A) Fission (B) Fusion (C) Alpha decay (D) Beta decay 33. What is the charge of a positron? (A) Positive (B) Negative (C) Neutral (D) It depends on the situation 34. What is the name of the phenomenon where an electron tunnels through a potential barrier it classically cannot surmount? (A) Photoelectric effect (B) Davisson-Germer effect (C) Compton effect (D) Quantum tunneling 35. What is the name of the process where a high-energy photon collides with a stationary electron, resulting in the photon losing energy and changing direction? (A) Compton effect (B) Photoelectric effect (C) Pair production (D) Electron capture 36. What is the name of the process where a particle and its corresponding antiparticle collide and annihilate each other? (A) Pair production (B) Electron capture (C) Annihilation (D) Fusion 37. What is the name of the process where a high-energy photon creates an electron and a positron? (A) Electron capture (B) Pair production (C) Annihilation (D) Fusion 38. What is the minimum energy required to ionize a hydrogen atom in its ground state? (A) 10.2 eV (B) 13.6 eV (C) 3.4 eV (D) 1.51 eV 39. Which of the following is a fundamental particle? (A) Neutron (B) All of the above (C) Electron (D) Proton 40. What is the name of the process where a nucleus splits into two smaller nuclei and releases a large amount of energy? (A) Fusion (B) Alpha decay (C) Fission (D) Beta decay 41. What is the charge of a neutron? (A) Positive (B) Negative (C) It depends on the situation (D) Neutral 42. Which force is responsible for binding electrons to the nucleus of an atom? (A) Weak nuclear force (B) Strong nuclear force (C) Electromagnetic force (D) Gravitational force 43. What is the name of the process where a radioactive nucleus emits a beta particle? (A) Beta decay (B) Alpha decay (C) Electron capture (D) Positron emission 44. What is the charge of an electron? (A) Positive (B) Neutral (C) Negative (D) It depends on the situation 45. What is the name of the particle consisting of two protons and two neutrons? (A) Beta particle (B) Gamma particle (C) Alpha particle (D) Positron 46. What is the name of the process where a positron is emitted from a radioactive nucleus? (A) Alpha decay (B) Positron emission (C) Beta decay (D) Electron capture 47. What is the name of the process where a nucleus absorbs an electron and converts it into a proton? (A) Alpha decay (B) Electron capture (C) Positron emission (D) Beta decay 48. What is the name of the process where two nuclei combine to form a heavier nucleus, releasing a large amount of energy? (A) Fission (B) Fusion (C) Alpha decay (D) Beta decay 49. What is the name of the process where a high-energy photon is absorbed by a nucleus and then re-emitted as two photons with lower energy? (A) Photoelectric effect (B) Annihilation (C) Pair production (D) Compton effect 50. What is the name of the phenomenon where a particle appears on both sides of a barrier without passing through it? (A) Diffraction (B) Reflection (C) Tunneling (D) Refraction