1. The branch of physics that deals with structure and behavior of atoms is called
A) Atomic physics
B) Nuclear physics
C) Classical mechanics
D) Thermodynamics
Answer: A) Atomic physics
Explanation: Atomic physics studies the structure and properties of atoms and their interactions.
2. The branch of physics that deals with nuclei and nuclear reactions is called
A) Nuclear physics
B) Atomic physics
C) Mechanics
D) Optics
Answer: A) Nuclear physics
Explanation: Nuclear physics focuses on the composition, structure, and transformations of atomic nuclei.
3. The smallest particle of an element which retains its properties is
A) Atom
B) Molecule
C) Proton
D) Electron
Answer: A) Atom
4. An atom consists of
A) Electrons, protons, and neutrons
B) Only electrons
C) Only protons
D) Only neutrons
Answer: A) Electrons, protons, and neutrons
5. The central part of an atom is called
A) Nucleus
B) Proton
C) Electron cloud
D) Orbit
Answer: A) Nucleus
6. The nucleus is made up of
A) Protons and neutrons
B) Electrons and protons
C) Only electrons
D) Positrons
Answer: A) Protons and neutrons
7. The particles revolving around the nucleus are
A) Electrons
B) Protons
C) Neutrons
D) Positrons
Answer: A) Electrons
8. The charge on an electron is
A) Negative
B) Positive
C) Neutral
D) Double positive
Answer: A) Negative
9. The charge on a proton is
A) Positive
B) Negative
C) Neutral
D) Zero
Answer: A) Positive
10. A neutron has
A) No charge
B) Positive charge
C) Negative charge
D) Double charge
Answer: A) No charge
11. The mass of an atom is concentrated in
A) The nucleus
B) Electrons
C) Outer shell
D) Orbit
Answer: A) The nucleus
Explanation: The nucleus contains protons and neutrons, which have almost all of the atom’s mass.
12. The first model of atom was proposed by
A) J.J. Thomson
B) Rutherford
C) Bohr
D) Dalton
Answer: D) Dalton
Explanation: Dalton’s atomic theory was the first to describe atoms as indivisible particles.
13. The “plum pudding model” of the atom was proposed by
A) J.J. Thomson
B) Rutherford
C) Bohr
D) Chadwick
Answer: A) J.J. Thomson
Explanation: Thomson proposed that electrons were embedded in a positive sphere like plums in pudding.
14. The Rutherford model of the atom is also known as
A) Nuclear model
B) Planetary model
C) Quantum model
D) Plum model
Answer: B) Planetary model
Explanation: In this model, electrons revolve around the nucleus like planets around the sun.
15. The Bohr model of atom explained
A) The stability of atom
B) Only mass
C) Magnetic properties
D) Nuclear reactions
Answer: A) The stability of atom
Explanation: Bohr introduced energy levels for electrons to explain stability.
16. The modern model of atom is based on
A) Quantum theory
B) Classical mechanics
C) Newton’s laws
D) Magnetism
Answer: A) Quantum theory
17. The nucleus of hydrogen atom consists of
A) One proton
B) One neutron
C) One electron
D) One proton and one neutron
Answer: A) One proton
18. The nucleus was discovered by
A) Rutherford
B) Bohr
C) Thomson
D) Dalton
Answer: A) Rutherford
19. The neutron was discovered by
A) James Chadwick
B) Rutherford
C) Bohr
D) Thomson
Answer: A) James Chadwick
20. The electron was discovered by
A) J.J. Thomson
B) Rutherford
C) Bohr
D) Dalton
Answer: A) J.J. Thomson
21. The number of protons in an atom is called
A) Atomic number
B) Mass number
C) Isotope number
D) Neutron number
Answer: A) Atomic number
22. The sum of protons and neutrons in an atom is called
A) Mass number
B) Atomic number
C) Isotope
D) Atomic weight
Answer: A) Mass number
23. Atoms of the same element with different number of neutrons are called
A) Isotopes
B) Isobars
C) Isotones
D) Molecules
Answer: A) Isotopes
24. Isotopes have same
A) Atomic number
B) Mass number
C) Neutron number
D) Density
Answer: A) Atomic number
25. Isobars have same
A) Mass number
B) Atomic number
C) Number of neutrons
D) Electrons
Answer: A) Mass number
26. The radioactive element used in cancer treatment is
A) Cobalt-60
B) Uranium-238
C) Carbon-14
D) Thorium
Answer: A) Cobalt-60
27. The element used as nuclear fuel is
A) Uranium
B) Carbon
C) Iron
D) Oxygen
Answer: A) Uranium
28. The process by which an unstable nucleus emits radiation is called
A) Radioactivity
B) Ionization
C) Fusion
D) Fission
Answer: A) Radioactivity
29. The three types of radioactive emissions are
A) Alpha, beta, and gamma rays
B) X-rays, UV, and infrared
C) Neutrons, electrons, photons
D) Heat, light, and sound
Answer: A) Alpha, beta, and gamma rays
30. The most penetrating radiation among them is
A) Gamma rays
B) Alpha rays
C) Beta rays
D) X-rays
Answer: A) Gamma rays
31. Alpha particles are
A) Helium nuclei
B) Electrons
C) Protons
D) Neutrons
Answer: A) Helium nuclei
32. Beta particles are
A) Fast-moving electrons
B) Protons
C) Photons
D) Neutrons
Answer: A) Fast-moving electrons
33. Gamma rays are
A) Electromagnetic waves
B) Charged particles
C) Alpha particles
D) Neutrons
Answer: A) Electromagnetic waves
34. The most ionizing radiation is
A) Alpha rays
B) Beta rays
C) Gamma rays
D) X-rays
Answer: A) Alpha rays
35. Radioactivity was discovered by
A) Henri Becquerel
B) Marie Curie
C) Rutherford
D) Bohr
Answer: A) Henri Becquerel
36. The husband-wife scientists who studied radioactivity were
A) Pierre and Marie Curie
B) Bohr and Rutherford
C) Thomson and Chadwick
D) Newton and Faraday
Answer: A) Pierre and Marie Curie
37. The unit of radioactivity is
A) Becquerel
B) Joule
C) Ampere
D) Volt
Answer: A) Becquerel
38. The old unit of radioactivity is
A) Curie
B) Joule
C) Weber
D) Tesla
Answer: A) Curie
39. The process of splitting a heavy nucleus into two lighter nuclei is called
A) Nuclear fission
B) Nuclear fusion
C) Ionization
D) Radiation
Answer: A) Nuclear fission
40. The process of combining two light nuclei to form a heavier nucleus is
A) Nuclear fusion
B) Nuclear fission
C) Ionization
D) Radioactivity
Answer: A) Nuclear fusion
41. Nuclear fission was discovered by
A) Otto Hahn and Strassmann
B) Marie Curie
C) Rutherford
D) Bohr
Answer: A) Otto Hahn and Strassmann
42. Nuclear fusion occurs in
A) Sun and stars
B) Atomic reactors
C) Earth’s core
D) Electric bulbs
Answer: A) Sun and stars
43. The energy released in the sun is due to
A) Nuclear fusion
B) Nuclear fission
C) Chemical reaction
D) Combustion
Answer: A) Nuclear fusion
44. The first artificial nuclear reaction was performed by
A) Rutherford
B) Bohr
C) Thomson
D) Curie
Answer: A) Rutherford
45. The first controlled nuclear chain reaction was carried out by
A) Enrico Fermi
B) Einstein
C) Marie Curie
D) Bohr
Answer: A) Enrico Fermi
46. The device used to control nuclear reaction is
A) Nuclear reactor
B) Generator
C) Transformer
D) Motor
Answer: A) Nuclear reactor
47. The main part of a nuclear reactor that slows down neutrons is
A) Moderator
B) Control rod
C) Fuel rod
D) Shield
Answer: A) Moderator
48. The rods used to control the rate of nuclear reaction are made of
A) Cadmium or boron
B) Iron
C) Copper
D) Lead
Answer: A) Cadmium or boron
49. The energy produced by a nuclear reaction is called
A) Nuclear energy
B) Chemical energy
C) Thermal energy
D) Solar energy
Answer: A) Nuclear energy
50. The main nuclear fuel used in reactors is
A) Uranium-235
B) Carbon-14
C) Lead-210
D) Sodium-24
Answer: A) Uranium-235
51. The main function of a moderator in a nuclear reactor is to
A) Slow down neutrons
B) Absorb neutrons
C) Produce heat
D) Reflect radiation
Answer: A) Slow down neutrons
Explanation: Slow neutrons are more effective in sustaining nuclear fission.
52. The material used as a moderator in reactors is
A) Graphite or heavy water
B) Steel
C) Aluminium
D) Lead
Answer: A) Graphite or heavy water
53. The rods that absorb extra neutrons in a reactor are called
A) Control rods
B) Fuel rods
C) Absorbers
D) Reflectors
Answer: A) Control rods
54. The heavy water used in reactors is
A) Water containing heavy hydrogen (deuterium)
B) Salty water
C) Acidic water
D) Pure distilled water
Answer: A) Water containing heavy hydrogen (deuterium)
55. The nuclear reactor used for generating electricity is called
A) Atomic power reactor
B) Solar reactor
C) Thermal reactor
D) Fusion reactor
Answer: A) Atomic power reactor
56. The first nuclear reactor was built by
A) Enrico Fermi
B) Rutherford
C) Curie
D) Einstein
Answer: A) Enrico Fermi
57. The first nuclear reactor was built in
A) Chicago (USA)
B) Paris
C) London
D) Moscow
Answer: A) Chicago (USA)
58. The first nuclear power plant in India is located at
A) Tarapur (Maharashtra)
B) Kalpakkam (Tamil Nadu)
C) Kaiga (Karnataka)
D) Kota (Rajasthan)
Answer: A) Tarapur (Maharashtra)
59. The main by-product of nuclear fission is
A) Heat energy
B) Light energy
C) Sound energy
D) Pressure
Answer: A) Heat energy
60. The energy released in nuclear fission is due to
A) Conversion of mass into energy
B) Chemical reaction
C) Combustion
D) Ionization
Answer: A) Conversion of mass into energy
61. Nuclear fusion requires
A) Very high temperature and pressure
B) Low temperature
C) Room temperature
D) Magnetic field only
Answer: A) Very high temperature and pressure
62. The hydrogen bomb is based on
A) Nuclear fusion
B) Nuclear fission
C) Radioactivity
D) Ionization
Answer: A) Nuclear fusion
63. The atom bomb is based on
A) Nuclear fission
B) Nuclear fusion
C) Chemical explosion
D) Electric discharge
Answer: A) Nuclear fission
64. The radioactive isotope used in carbon dating is
A) Carbon-14
B) Uranium-235
C) Thorium-232
D) Cobalt-60
Answer: A) Carbon-14
Explanation: Carbon-14 helps determine the age of fossils and ancient materials.
65. The half-life of a radioactive element is the time taken for
A) Half of the nuclei to decay
B) All nuclei to decay
C) Double decay
D) Ionization
Answer: A) Half of the nuclei to decay
66. The half-life of Carbon-14 is approximately
A) 5730 years
B) 50 years
C) 100 years
D) 1 year
Answer: A) 5730 years
67. The radiation used to kill cancer cells is
A) Gamma rays
B) Alpha rays
C) Beta rays
D) X-rays
Answer: A) Gamma rays
68. The isotope used in radiocarbon dating is
A) Carbon-14
B) Nitrogen-14
C) Oxygen-16
D) Hydrogen-1
Answer: A) Carbon-14
69. The isotope used in medical diagnosis is
A) Iodine-131
B) Uranium-238
C) Carbon-12
D) Sodium-23
Answer: A) Iodine-131
Explanation: It is used to check thyroid gland function.
70. The isotope used in detecting blood circulation is
A) Sodium-24
B) Iodine-131
C) Uranium-235
D) Carbon-14
Answer: A) Sodium-24
71. The isotope used in detecting leaks in gas pipelines is
A) Argon-41
B) Carbon-12
C) Oxygen-18
D) Hydrogen-1
Answer: A) Argon-41
72. The isotope used in agriculture to study plant metabolism is
A) Phosphorus-32
B) Carbon-14
C) Iodine-131
D) Uranium-238
Answer: A) Phosphorus-32
73. The radiation which can be stopped by a sheet of paper is
A) Alpha radiation
B) Beta radiation
C) Gamma radiation
D) X-rays
Answer: A) Alpha radiation
74. The radiation that can penetrate lead sheets partially is
A) Gamma rays
B) Beta rays
C) Alpha rays
D) Ultraviolet rays
Answer: A) Gamma rays
75. The Geiger-Muller counter is used to detect
A) Radiation
B) Current
C) Voltage
D) Magnetic field
Answer: A) Radiation
76. The radioactive decay process continues until
A) A stable nucleus is formed
B) The element disappears
C) Energy is lost
D) It becomes heavy
Answer: A) A stable nucleus is formed
77. Nuclear fusion produces
A) More energy than fission
B) Less energy than fission
C) Equal energy
D) No energy
Answer: A) More energy than fission
78. The energy from the sun is due to
A) Fusion of hydrogen atoms
B) Fission of uranium
C) Burning gases
D) Chemical reactions
Answer: A) Fusion of hydrogen atoms
79. The hydrogen atoms combine in the sun to form
A) Helium
B) Oxygen
C) Carbon
D) Nitrogen
Answer: A) Helium
80. The radiation that can pass through the human body easily is
A) Gamma rays
B) Alpha rays
C) Beta rays
D) Light rays
Answer: A) Gamma rays
81. X-rays were discovered by
A) Wilhelm Roentgen
B) Becquerel
C) Curie
D) Rutherford
Answer: A) Wilhelm Roentgen
82. X-rays are used in
A) Medical imaging and security scanning
B) Food preparation
C) Communication
D) Painting
Answer: A) Medical imaging and security scanning
83. The nucleus of an atom is held together by
A) Strong nuclear force
B) Gravitational force
C) Electrostatic force
D) Friction
Answer: A) Strong nuclear force
84. The strong nuclear force is effective over
A) Very short distances
B) Long distances
C) Infinite distances
D) Medium distances
Answer: A) Very short distances
85. The energy obtained from atomic nuclei is called
A) Nuclear energy
B) Thermal energy
C) Mechanical energy
D) Solar energy
Answer: A) Nuclear energy
86. Nuclear energy is used in
A) Power generation and medical treatments
B) Agriculture only
C) Cooking
D) Transportation
Answer: A) Power generation and medical treatments
87. The harmful effect of nuclear radiation on living cells is
A) Genetic mutation and cell damage
B) Better growth
C) Cooling
D) Strength increase
Answer: A) Genetic mutation and cell damage
88. The most dangerous radiation for living cells is
A) Gamma rays
B) Beta rays
C) Alpha rays
D) Visible light
Answer: A) Gamma rays
89. The radioactive element used in luminous paints is
A) Radium
B) Uranium
C) Carbon
D) Sodium
Answer: A) Radium
90. The device used to measure exposure to radiation is
A) Dosimeter
B) Thermometer
C) Voltmeter
D) Barometer
Answer: A) Dosimeter
91. Radioactive wastes are disposed of by
A) Burying them deep underground
B) Releasing into rivers
C) Burning
D) Exposing to sunlight
Answer: A) Burying them deep underground
92. The radiation that causes the highest ionization in air is
A) Alpha radiation
B) Beta radiation
C) Gamma radiation
D) X-rays
Answer: A) Alpha radiation
93. The nuclear reactor that produces more fuel than it consumes is
A) Breeder reactor
B) Fusion reactor
C) Thermal reactor
D) Fast reactor
Answer: A) Breeder reactor
94. The reactor that uses fast neutrons is
A) Fast breeder reactor
B) Slow reactor
C) Fusion reactor
D) Pressurized reactor
Answer: A) Fast breeder reactor
95. The isotope used as a fuel in fast breeder reactors is
A) Plutonium-239
B) Uranium-238
C) Carbon-14
D) Sodium-24
Answer: A) Plutonium-239
96. The radioactive element found naturally in pitchblende ore is
A) Uranium
B) Carbon
C) Sodium
D) Cobalt
Answer: A) Uranium
97. The unit used to measure the biological effect of radiation is
A) Sievert
B) Volt
C) Ohm
D) Watt
Answer: A) Sievert
98. The country where the first atomic bomb was dropped is
A) Japan
B) Germany
C) USA
D) Russia
Answer: A) Japan
Explanation: The bombs were dropped on Hiroshima and Nagasaki in 1945.
99. The scientist who proposed the relation between mass and energy was
A) Albert Einstein
B) Rutherford
C) Bohr
D) Curie
Answer: A) Albert Einstein
100. The peaceful use of atomic energy is in
A) Power generation, medicine, and research
B) Weapon making only
C) Food heating
D) Magnetic devices
Answer: A) Power generation, medicine, and research