THE DAWN OF
MODERN PHYSICS
1. Which of the following best defines a frame of reference in physics?
a) A coordinate system used to describe the position of an object.
b) The rate at which an object changes its position.
c) The force exerted by an object on its surroundings.
d) The total energy possessed by an object.
2. An inertial reference frame is a frame of reference:
a) That is stationary and not moving.
b) That is accelerating uniformly.
c) That is at rest or moving with a constant velocity.
d) That is subject to external forces.
3. Frames of reference in uniform relative motion:
a) Are stationary with respect to each other.
b) Are accelerating uniformly.
c) Are moving with different velocities.
d) Are moving with the same velocity.
4. According to the principle of relativity:
a) The laws of physics are the same in all inertial reference frames.
b) The laws of physics are different in different reference frames.
c) Only one reference frame can be considered inertial.
d) Time and space are absolute quantities.
5. Which of the following is NOT a postulate of the special theory of relativity?
a) The speed of light is constant in all inertial reference frames.
b) The laws of physics are the same in all inertial reference frames.
c) The concept of absolute time.
d) The principle of relativity holds true for all physical phenomena.
6. Which of the following is a consequence of the special theory of relativity?
a) Mass variation with velocity.
b) Time contraction with velocity.
c) Length dilation with velocity.
d) All of the above.
7. Mass variation, as predicted by special relativity, refers to:
a) The increase in mass as an object approaches the speed of light.
b) The decrease in mass as an object approaches the speed of light.
c) The constant mass of an object regardless of its velocity.
d) The change in mass due to gravitational effects.
8. Length contraction refers to:
a) The shortening of an object's length in the direction of its motion.
b) The elongation of an object's length in the direction of its motion.
c) The change in size of an object independent of its motion.
d) The variation in the width of an object due to its velocity.
9. Time dilation, as described by special relativity, means that:
a) Time slows down for objects in motion relative to an observer.
b) Time speeds up for objects in motion relative to an observer.
c) Time remains the same regardless of an object's velocity.
d) Time is absolute and unaffected by motion.
10. Which equation represents the mass-energy relation according to Einstein's theory?
a) E = mc^2
b) F = ma
c) P = mv
d) W = Fd
11. Black body radiation and quantum theory describe:
a) The behavior of light emitted by a black hole.
b) The relationship between temperature and energy.
c) The interaction of light with charged particles.
d) The emission and absorption of electromagnetic radiation by objects.
12. Which scientist formulated the Planck's law in quantum theory?
a) Albert Einstein
b) Max Planck
c) Niels Bohr
d) Werner Heisenberg
13. The photon is a:
a) Elementary particle with no mass.
b) A type of electromagnetic wave.
c) A particle of light with both wave and particle properties.
d) A subatomic particle found in the nucleus.
14. The photoelectric effect is best explained by:
a) Classical wave theory.
b) Newton's laws of motion.
c) Quantum theory.
d) Relativity theory.
15. How did Einstein explain the photoelectric effect based on quantum theory?
a) By proposing that light consists of particles called photons.
b) By suggesting that electrons have wave-like properties.
c) By introducing the concept of energy quantization.
d) By postulating the existence of subatomic particles.
16. Photo cells are commonly used in:
a) Solar panels for generating electricity.
b) Microscopes for observing cells.
c) Telescopes for studying distant galaxies.
d) X-ray machines for medical imaging.
17. The Compton effect refers to:
a) The scattering of light by small particles.
b) The interaction of high-energy photons with matter.
c) The emission of radiation from black holes.
d) The absorption of electromagnetic waves by a medium.
18. Pair production and annihilation of matter involve:
a) The creation of matter-antimatter pairs from high-energy photons.
b) The decay of unstable atomic nuclei.
c) The conversion of mass into energy.
d) The formation of chemical bonds between atoms.
19. The wave nature of particles and De Broglie's hypothesis propose that:
a) All particles exhibit both wave and particle properties.
b) Only light waves exhibit particle properties.
c) Particles are always localized in a specific position.
d) Waves can only be produced by macroscopic objects.
20. The Davisson and Germer experiment provided evidence for:
a) The particle-like behavior of electrons.
b) The existence of photons.
c) The wave nature of light.
d) The conservation of energy.
21. The uncertainty principle states that:
a) The position and momentum of a particle cannot be simultaneously known with perfect accuracy.
b) The energy of a system is conserved over time.
c) The speed of light is constant in all reference frames.
d) The force exerted by an object is equal to its mass times acceleration.
22. Frames of reference are used to describe the:
a) Speed of an object.
b) Acceleration of an object.
c) Position of an object.
d) Mass of an object.
23. An inertial reference frame is a frame of reference in which:
a) Objects are at rest.
b) Objects are moving at a constant speed.
c) Objects are accelerating.
d) Objects are subject to external forces.
24. Frames of reference in uniform relative motion:
a) Are stationary with respect to each other.
b) Are accelerating with respect to each other.
c) Are moving at different velocities.
d) Are moving at the same velocity.
25. The principle of relativity states that:
a) The laws of physics are the same in all frames of reference.
b) The laws of physics are different in different frames of reference.
c) Time and space are absolute quantities.
d) The speed of light is constant in all frames of reference.
26. Which of the following is a postulate of the special theory of relativity?
a) The laws of physics are different in different frames of reference.
b) The speed of light is variable.
c) The concept of absolute time.
d) The speed of light is constant in all frames of reference.
27. Consequences of the special theory of relativity include:
a) Mass variation with velocity.
b) Time dilation.
c) Length contraction.
d) All of the above.
28. Mass variation, as predicted by special relativity, refers to:
a) The increase in mass as an object approaches the speed of light.
b) The decrease in mass as an object approaches the speed of light.
c) The constant mass of an object regardless of its velocity.
d) The change in mass due to gravitational effects.
29. Length contraction refers to:
a) The shortening of an object's length in the direction of its motion.
b) The elongation of an object's length in the direction of its motion.
c) The change in size of an object independent of its motion.
d) The variation in the width of an object due to its velocity.
30. Time dilation, as described by special relativity, means that:
a) Time slows down for objects in motion relative to an observer.
b) Time speeds up for objects in motion relative to an observer.
c) Time remains the same regardless of an object's velocity.
d) Time is absolute and unaffected by motion.
31. The equation E = mc^2 represents:
a) The mass-energy relation.
b) Newton's second law of motion.
c) The conservation of angular momentum.
d) The relationship between mass and velocity.
32. Black body radiation and quantum theory are related to:
a) The behavior of light emitted by a black hole.
b) The relationship between temperature and energy.
c) The interaction of light with charged particles.
d) The emission and absorption of electromagnetic radiation by objects.
33. Who formulated the Planck's law in quantum theory?
a) Albert Einstein
b) Max Planck
c) Niels Bohr
d) Werner Heisenberg
34. The photon is a particle that:
a) Has no mass.
b) Behaves as both a particle and a wave.
c) Exists only in a vacuum.
d) Has the same properties as an electron.
35. The photoelectric effect is best explained by:
a) Classical wave theory.
b) Newton's laws of motion.
c) Quantum theory.
d) Relativity theory.
36. Einstein explained the photoelectric effect based on quantum theory by:
a) Proposing that light consists of particles called photons.
b) Suggesting that electrons have wave-like properties.
c) Introducing the concept of energy quantization.
d) Postulating the existence of subatomic particles.
37. Photo cells are commonly used in:
a) Solar panels for generating electricity.
b) Microscopes for observing cells.
c) Telescopes for studying distant galaxies.
d) X-ray machines for medical imaging.
38. The Compton effect refers to:
a) The scattering of light by small particles.
b) The interaction of high-energy photons with matter.
c) The emission of radiation from black holes.
d) The absorption of electromagnetic waves by a medium.
39. Pair production and annihilation of matter involve:
a) The creation of matter-antimatter pairs from high-energy photons.
b) The decay of unstable atomic nuclei.
c) The conversion of mass into energy.
d) The formation of chemical bonds between atoms.
40. The wave nature of particles and De Broglie's hypothesis propose that:
a) All particles exhibit both wave and particle properties.
b) Only light waves exhibit particle properties.
c) Particles are always localized in a specific position.
d) Waves can only be produced by macroscopic objects.
41. The Davisson and Germer experiment provided evidence for:
a) The particle-like behavior of electrons.
b) The existence of photons.
c) The wave nature of light.
d) The conservation of energy.
42. The uncertainty principle states that:
a) The position and momentum of a particle cannot be simultaneously known with perfect accuracy.
b) The energy of a system is conserved over time.
c) The speed of light is constant in all reference frames.
d) The force exerted by an object is equal to its mass times acceleration.
43. According to special relativity, the mass of an object:
a) Increases as its velocity increases.
b) Decreases as its velocity increases.
c) Remains constant regardless of velocity.
d) Depends on the object's acceleration.
44. Time dilation occurs when:
a) Time runs slower for a moving object compared to a stationary observer.
b) Time runs faster for a moving object compared to a stationary observer.
c) Time remains the same for a moving object as for a stationary observer.
d) Time is independent of the motion of an object.
45. Length contraction refers to the phenomenon where:
a) An object appears shorter in the direction of its motion when observed from a stationary frame.
b) An object appears longer in the direction of its motion when observed from a stationary frame.
c) The length of an object remains unchanged regardless of its motion.
d) The width of an object changes with its velocity.
46. The mass-energy relation, expressed by the equation E = mc^2, states that:
a) Energy and mass are equivalent and can be converted into each other.
b) Energy is proportional to the square of the speed of light.
c) Mass is directly proportional to the energy of an object.
d) The total energy of a system is conserved.
47. According to quantum theory, the energy of a system is:
a) Quantized, meaning it can only have certain discrete values.
b) Continuous, meaning it can have any value.
c) Zero, unless external forces act on the system.
d) Independent of the properties of the system.
48. Planck's law describes the:
a) Relationship between the temperature and energy of a system.
b) Interaction between charged particles and electromagnetic waves.
c) Scattering of light by small particles.
d) Formation and annihilation of matter-antimatter pairs.
49. Which of the following is NOT a consequence of special relativity?
a) Time dilation
b) Mass-energy equivalence
c) Length contraction
d) Gravitational force
50. The wave-particle duality refers to the concept that:
a) All particles exhibit wave-like properties.
b) All waves can behave as particles.
c) Both waves and particles have dual characteristics.
d) Waves and particles are completely separate phenomena.
51. According to De Broglie's hypothesis, particles such as electrons and protons:
a) Can exhibit wave-like behavior.
b) Can only be described as discrete particles.
c) Have no connection to the wave nature of light.
d) Have fixed positions in space at all times.
52. The Davisson and Germer experiment demonstrated the wave nature of:
a) Electrons
b) Protons
c) Photons
d) Neutrons
53. The uncertainty principle, formulated by Heisenberg, states that:
a) It is impossible to measure the position and momentum of a particle simultaneously with perfect accuracy.
b) The speed of light is the fundamental speed limit in the universe.
c) Energy can neither be created nor destroyed, only transferred or transformed.
d) The total angular momentum of a closed system remains constant.
54. According to special relativity, which of the following is true?
a) The laws of physics are the same in all inertial reference frames.
b) The laws of physics vary depending on the observer's frame of reference.
c) The speed of light is not constant in all reference frames.
d) Time is an absolute quantity unaffected by motion.
55. In special relativity, time dilation occurs because:
a) The speed of light is constant in all reference frames.
b) Time is relative and depends on the observer's motion.
c) Objects contract in the direction of their motion.
d) The mass of an object increases with velocity.
56. According to Einstein's theory of relativity, the speed of light in a vacuum is:
a) Approximately 300,000 meters per second.
b) Approximately 3 million meters per second.
c) Approximately 3 billion meters per second.
d) Approximately 300 billion meters per second.
57. The photoelectric effect is the phenomenon where:
a) Light exhibits both particle and wave properties.
b) Electrons are emitted from a material when exposed to light.
c) Light is scattered by small particles in its path.
d) Electromagnetic waves propagate through space.
58. The energy of a photon is directly proportional to its:
a) Wavelength.
b) Frequency.
c) Amplitude.
d) Velocity.
59. According to Einstein's explanation of the photoelectric effect, the energy of a photon is related to:
a) The amplitude of the light wave.
b) The frequency of the light wave.
c) The speed of the light wave.
d) The wavelength of the light wave.
60. Photo cells are commonly used in:
a) Solar panels.
b) Nuclear reactors.
c) Laser devices.
d) X-ray machines.
61. The Compton effect is the phenomenon where:
a) Light is refracted when passing through a medium.
b) Light is reflected by a mirror.
c) Light is scattered by electrons in a material, resulting in a change in wavelength.
d) Light is absorbed by a material, causing it to emit electromagnetic radiation.
62. Pair production refers to the creation of:
a) Matter and antimatter particles from high-energy photons.
b) Light and sound waves from a single source.
c) Electrons and protons from nuclear reactions.
d) Chemical bonds between atoms.
63. The wave nature of particles is supported by the:
a) Double-slit experiment.
b) Law of conservation of energy.
c) Kinetic theory of gases.
d) Principle of superposition.
64. The De Broglie hypothesis proposes that particles, such as electrons, have:
a) Only particle-like properties.
b) Only wave-like properties.
c) Both particle and wave properties.
d) No definite properties.
65. The Davisson and Germer experiment provided experimental evidence for:
a) The wave nature of electrons.
b) The existence of photons.
c) The particle-like behavior of light.
d) The conservation of angular momentum.
66. The uncertainty principle states that:
a) It is impossible to simultaneously know the position and momentum of a particle with absolute certainty.
b) The total energy of a system remains constant over time.
c) The speed of light is constant in all inertial frames of reference.
d) The gravitational force depends on the mass and distance of objects.
67. Frames of reference are used to describe:
a) The position and motion of objects.
b) The temperature and pressure of a system.
c) The energy and wavelength of electromagnetic waves.
d) The electrical potential and current in a circuit.
68. An inertial reference frame is a frame of reference:
a) In which objects are at rest.
b) That is moving at a constant speed.
c) That is accelerating.
d) That is subjected to external forces.
69. The principle of relativity states that:
a) The laws of physics are the same in all inertial reference frames.
b) The laws of physics vary depending on the observer's motion.
c) The speed of light is different in different reference frames.
d) Time is an absolute quantity unaffected by motion.
70. Mass-energy equivalence is described by the equation:
a) E = mc^2.
b) F = ma.
c) P = mv.
d) KE = 1/2mv^2.
ANSWER KEY:
1. c) Position of an object.
2. a) Objects are at rest.
3. c) Are moving at different velocities.
4. a) The laws of physics are the same in all frames of reference.
5. d) The speed of light is constant in all frames of reference.
6. d) All of the above.
7. a) The increase in mass as an object approaches the speed of light.
8. a) The shortening of an object's length in the direction of its motion.
9. a) Time slows down for objects in motion relative to an observer.
10. a) The mass-energy relation.
11. b) The relationship between temperature and energy.
12. b) Max Planck
13. b) Behaves as both a particle and a wave.
14. c) Quantum theory.
15. a) Proposing that light consists of particles called photons.
16. a) Solar panels for generating electricity.
17. b) The interaction of high-energy photons with matter.
18. a) The creation of matter-antimatter pairs from high-energy photons.
19. a) All particles exhibit both wave and particle properties.
20. a) Electrons
21. a) The position and momentum of a particle cannot be simultaneously known with perfect accuracy.
22. a) Increases as its velocity increases.
23. a) Time runs slower for a moving object compared to a stationary observer.
24. a) An object appears shorter in the direction of its motion when observed from a stationary frame.
25. a) Energy and mass are equivalent and can be converted into each other.
26. a) Quantized, meaning it can only have certain discrete values.
27. a) The laws of physics are the same in all inertial reference frames.
28. a) The speed of light is constant in all reference frames.
29. b) Time is relative and depends on the observer's motion.
30. a) Approximately 300,000 meters per second.
31. b) Electrons are emitted from a material when exposed to light.
32. b) Frequency.
33. b) The frequency of the light wave.
34. a) Solar panels.
35. c) Light is scattered by electrons in a material, resulting in a change in wavelength.
36. a) Matter and antimatter particles from high-energy photons.
37. a) Double-slit experiment.
38. c) Both particle and wave properties.
39. a) The wave nature of electrons.
40. a) It is impossible to simultaneously know the position and momentum of a particle with absolute certainty.
41. a) The position and motion of objects.
42. b) That is moving at a constant speed.
43. a) The laws of physics are the same in all inertial reference frames.
44. a) E = mc^2.
45. a) Photons are particles of light.
46. b) Electrons are emitted from a material when exposed to light.
47. a) Electrons.
48. c) It is impossible to determine the path of an electron.
49. a) The energy of a photon is directly proportional to its frequency.
50. b) To measure the energy of photons.
51. b) The scattering of X-rays by electrons.
52. b) The number of electrons emitted from a metal increases with the intensity of light.
53. c) Electromagnetic waves.
54. a) The frequency of the light wave.
55. c) Materials that emit light when exposed to radiation.
56. c) Energy is quantized and can only exist in discrete packets.
57. c) The energy of the emitted electrons depends on the frequency of the incident light.
58. b) X-ray imaging in medical diagnostics.
59. c) The wavelength of light decreases when it interacts with matter.
60. d) Both particle and wave characteristics.
61. c) The scattering of photons by electrons.
62. b) Antimatter particles and their annihilation with matter particles.
63. a) Photons exhibit wave-particle duality.
64. c) The interaction of high-energy photons with atomic nuclei.
65. a) The wave nature of particles is supported by experimental observations.
66. b) The energy and momentum of a particle cannot be simultaneously known with absolute certainty.
67. a) The position and motion of objects.
68. b) That is moving at a constant speed.
69. a) The laws of physics are the same in all inertial reference frames.
70. a) E = mc^2.
