Class 12 भौतिकी Ch-13 नाभिक MCQs Exam 2027

Chapter: Nuclei (नाभिक)

Topic 1: Composition and Structure of Nucleus

1. The central part of an atom where almost the entire mass is concentrated is:

   (A) Shell

   (B) Nucleus

   (C) Orbit

   (D) Electron cloud

2. Protons and neutrons together inside the nucleus are called:

   (A) Leptons

   (B) Nucleons

   (C) Photons

   (D) Positrons

3. One atomic mass unit (1 amu) is equivalent to: [BSEB, 2016]

   (A) $1.66 \times 10^{-27}$ kg

   (B) $1.66 \times 10^{-24}$ kg

   (C) $9.1 \times 10^{-31}$ kg

   (D) $1.6 \times 10^{-19}$ kg

4. The number of neutrons in the nucleus $_{Z}^{A}X$ is: [BSEB, 2021]

   (A) $Z$

   (B) $A$

   (C) $A – Z$

   (D) $A + Z$

5. Which of the following is not present in the nucleus of a Hydrogen atom?

   (A) Proton

   (B) Electron

   (C) Neutron

   (D) Charge

6. Neutrons were discovered by: [BSEB, 2012]

   (A) Thomson

   (B) Chadwick

   (C) Rutherford

   (D) Bohr

7. Atoms having the same atomic number but different mass numbers are: [BSEB, 2022]

   (A) Isobars

   (B) Isotopes

   (C) Isotones

   (D) Isomers

8. Isotopes of an element have the same number of:

   (A) Neutrons

   (B) Protons

   (C) Nucleons

   (D) Mass number

9. Atoms having the same mass number but different atomic numbers are:

   (A) Isotopes

   (B) Isobars

   (C) Isotones

   (D) Isomers

10. Which of the following are isotones?

    (A) Same number of protons

    (B) Same number of neutrons

    (C) Same mass number

    (D) Same chemical properties

11. The density of nuclear matter is of the order of:

    (A) $10^{17}$ kg/m³

    (B) $10^{10}$ kg/m³

    (C) $10^{3}$ kg/m³

    (D) $10^{-15}$ kg/m³

12. The nuclear density is:

    (A) Constant for all nuclei

    (B) Proportional to $A$

    (C) Proportional to $R$

    (D) Variable for different isotopes

13. The radius of a nucleus ($R$) is proportional to: [BSEB, 2021]

    (A) $A$

    (B) $A^{1/3}$

    (C) $A^{2/3}$

    (D) $A^{-1/3}$

14. The constant $R_0$ in the formula $R = R_0 A^{1/3}$ is approximately:

    (A) 1.2 Fermi

    (B) 1.2 Angstrom

    (C) 1.2 meter

    (D) 0.53 Fermi

15. If the mass number $A=64$, then the nuclear radius is how many times $R_0$?

    (A) 2 times

    (B) 4 times

    (C) 8 times

    (D) 64 times

Topic 2: Nuclear Forces and Stability

16. Nuclear forces are: [BSEB, 2018]

    (A) Charge dependent

    (B) Long range forces

    (C) Strongest forces in nature

    (D) Gravitational in nature

17. Nuclear force acts between:

    (A) $p-p$ only

    (B) $n-n$ only

    (C) $n-p$ only

    (D) All of these

18. The range of nuclear force is:

    (A) $10^{-15}$ m

    (B) $10^{-10}$ m

    (C) $10^{-8}$ m

    (D) Infinite

19. Nuclear forces are non-central forces:

    (A) True

    (B) False

    (C) Only for heavy nuclei

    (D) Not determined

20. The stability of a nucleus is decided by:

    (A) Total number of protons

    (B) Binding energy per nucleon

    (C) Size of the nucleus

    (D) Atomic number

21. The most stable nucleus is:

    (A) $^{4}He$

    (B) $^{56}Fe$

    (C) $^{238}U$

    (D) $^{16}O$

22. For a stable light nucleus, the $N/Z$ ratio is:

    (A) 1

    (B) 1.6

    (C) 2

    (D) 0.5

23. As the mass number $A$ increases, the binding energy per nucleon:

    (A) Increases continuously

    (B) Decreases continuously

    (C) First increases then decreases

    (D) Remains constant

24. Binding energy of a nucleus is due to:

    (A) Mass defect

    (B) Electronic energy

    (C) Gravitational force

    (D) Magnetic force

25. The energy equivalent of 1 amu is: [BSEB, 2019]

    (A) 931 MeV

    (B) 931 eV

    (C) 13.6 eV

    (D) 1.6 MeV

Topic 3: Mass-Energy Equivalence & Binding Energy

26. 26. Einstein’s mass-energy relation is: [BSEB, 2015]

        (A) $E = mc^2$

        (B) $E = m/c^2$

        (C) $E = mc$

        (D) $E = m^2c$

    27. The difference between the sum of masses of nucleons and the actual mass of the nucleus is:

        (A) Mass defect

        (B) Binding energy

        (C) Packing fraction

        (D) Mean life

    28. Binding energy ($B.E.$) is equal to:

        (A) $\Delta m \times c^2$

        (B) $\Delta m / c^2$

        (C) $m \times c$

        (D) $h\nu$

    29. Packing fraction is defined as:

        (A) Mass defect per nucleon

        (B) Total binding energy

        (C) Ratio of $Z$ to $A$

        (D) Nuclear density

    30. If the packing fraction is negative, the nucleus is:

        (A) Stable

        (B) Unstable

        (C) Radioactive

        (D) Large

    31. 1 MeV is equal to:

        (A) $1.6 \times 10^{-13}$ J

        (B) $1.6 \times 10^{-19}$ J

        (C) $10^6$ J

        (D) $1.6 \times 10^{-16}$ J

    32. The binding energy per nucleon for $^{56}Fe$ is approximately:

        (A) 8.8 MeV

        (B) 7.6 MeV

        (C) 2.2 MeV

        (D) 1.1 MeV

    33. When a nucleus splits into two smaller nuclei, the process is:

        (A) Fusion

        (B) Fission

        (C) Radioactivity

        (D) Ionization

    34. When two light nuclei combine to form a heavy nucleus, the process is:

        (A) Fusion

        (B) Fission

        (C) Alpha decay

        (D) K-capture

    35. Solar energy is generated by: [BSEB, 2023]

        (A) Nuclear Fission

        (B) Nuclear Fusion

        (C) Chemical reaction

        (D) Burning of Coal

Topic 4: Radioactivity (Alpha, Beta, Gamma Decay)

36. 36. Radioactivity was discovered by:

        (A) Madam Curie

        (B) Henri Becquerel

        (C) Rutherford

        (D) Roentgen

    37. The SI unit of radioactivity is:

        (A) Curie

        (B) Becquerel

        (C) Rutherford

        (D) Fermi

    38. 1 Curie is equal to how many disintegrations per second?

        (A) $3.7 \times 10^{10}$

        (B) $3.7 \times 10^7$

        (C) $10^6$

        (D) 1

    39. The radioactive decay law is represented as:

        (A) $N = N_0 e^{-\lambda t}$

        (B) $N = N_0 e^{\lambda t}$

        (C) $N = N_0 / \lambda t$

        (D) $N = \lambda e^{-t}$

    40. The relation between half-life ($T_{1/2}$) and decay constant ($\lambda$) is: [BSEB, 2021]

        (A) $T_{1/2} = 0.693 / \lambda$

        (B) $T_{1/2} = \lambda / 0.693$

        (C) $T_{1/2} = 0.693 \lambda$

        (D) $T_{1/2} = 1/\lambda$

    41. Mean life ($\tau$) is related to decay constant ($\lambda$) as: [BSEB, 2022]

        (A) $\tau = 1/\lambda$

        (B) $\tau = 0.693 / \lambda$

        (C) $\tau = \lambda$

        (D) $\tau = 2\lambda$

    42. After three half-lives, the fraction of the original sample left is:

        (A) 1/2

        (B) 1/4

        (C) 1/8

        (D) 1/16

    43. Which radiation has the highest penetrating power? [BSEB, 2019]

        (A) $\alpha$-rays

        (B) $\beta$-rays

        (C) $\gamma$-rays

        (D) X-rays

    44. Which radiation has the highest ionizing power? [BSEB, 2021]

        (A) $\alpha$-rays

        (B) $\beta$-rays

        (C) $\gamma$-rays

        (D) Neutrons

    45. An $\alpha$-particle is identical to: [BSEB, 2020]

        (A) Hydrogen nucleus

        (B) Helium nucleus

        (C) Electron

        (D) Proton

    46. When an $\alpha$-particle is emitted, the mass number decreases by:

        (A) 2

        (B) 4

        (C) 1

        (D) 0

    47. When a $\beta^-$-particle is emitted, the atomic number:

        (A) Increases by 1

        (B) Decreases by 1

        (C) Decreases by 2

        (D) Remains same

    48. $\beta$-rays are fast moving: [BSEB, 2020]

        (A) Protons

        (B) Electrons

        (C) Neutrons

        (D) Photons

    49. $\gamma$-rays are: [BSEB, 2018]

        (A) Positively charged

        (B) Negatively charged

        (C) Electromagnetic waves

        (D) Heavy particles

    50. Which radiation is not deflected by electric or magnetic fields? [BSEB, 2021]

        (A) $\alpha$-rays

        (B) $\beta$-rays

        (C) $\gamma$-rays

        (D) Cathode rays

51. The emission of a neutrino occurs during:

    (A) $\alpha$-decay

    (B) $\beta$-decay

    (C) $\gamma$-decay

    (D) Fission

52. Carbon dating is used to determine the age of: [BSEB, 2015]

    (A) Rocks

    (B) Fossils

    (C) Stars

    (D) Planets

53. The decay constant ($\lambda$) depends on:

    (A) Temperature

    (B) Pressure

    (C) Nature of the material

    (D) Amount of sample

54. The activity of a radioactive sample is measured in:

    (A) Henry

    (B) Becquerel

    (C) Tesla

    (D) Watt

55. If a nucleus $^{238}_{92}U$ emits an $\alpha$-particle, the new nucleus will be:

    (A) $^{234}_{90}Th$

    (B) $^{234}_{92}U$

    (C) $^{238}_{90}Th$

    (D) $^{236}_{91}Pa$

Topic 5: Nuclear Reactor and Fission/Fusion

56. The first controlled nuclear fission was carried out by:

    (A) Fermi

    (B) Bohr

    (C) Einstein

    (D) Rutherford

57. The moderator used in a nuclear reactor is: [BSEB, 2017]

    (A) Heavy water

    (B) Graphite

    (C) Beryllium

    (D) All of these

58. Control rods in a nuclear reactor are made of: [BSEB, 2019]

    (A) Cadmium

    (B) Uranium

    (C) Graphite

    (D) Plutonium

59. The function of a moderator is to:

    (A) Stop the reaction

    (B) Slow down neutrons

    (C) Accelerate neutrons

    (D) Absorb neutrons

60. For a stable chain reaction, the multiplication factor ($k$) should be:

    (A) $k < 1$

    (B) $k = 1$

    (C) $k > 1$

    (D) $k = 0$

61. Nuclear fusion takes place at:

    (A) Low temperature

    (B) High temperature and high pressure

    (C) Room temperature

    (D) Very low pressure

62. The Hydrogen bomb is based on: [BSEB, 2018]

    (A) Nuclear Fission

    (B) Nuclear Fusion

    (C) Chemical reaction

    (D) None of these

63. The Atom bomb is based on:

    (A) Controlled fission

    (B) Uncontrolled fission

    (C) Fusion

    (D) Alpha decay

64. Which of the following is used as fuel in a nuclear reactor?

    (A) $^{235}U$

    (B) $^{238}U$

    (C) $^{232}Th$

    (D) $^{12}C$

65. The energy released in one fission of $^{235}U$ is approximately:

    (A) 200 MeV

    (B) 20 MeV

    (C) 2 MeV

    (D) 931 MeV

66. Which particle is used to trigger nuclear fission in Uranium?

    (A) Proton

    (B) Alpha particle

    (C) Slow neutron

    (D) Electron

67. Critical mass is related to:

    (A) Nuclear fusion

    (B) Nuclear fission chain reaction

    (C) Radioactivity

    (D) Atomic size

68. Coolant used in a nuclear reactor can be:

    (A) Water

    (B) Molten sodium

    (C) Liquid oxygen

    (D) Both (A) and (B)

69. Breeder reactor produces:

    (A) More fuel than it consumes

    (B) No energy

    (C) Only alpha particles

    (D) Heavy water

70. The source of stellar energy is:

    (A) Proton-Proton cycle

    (B) Carbon-Nitrogen cycle

    (C) Both (A) and (B)

    (D) Fission of heavy nuclei

Topic 6: Miscellaneous & Advanced MCQs

71. The mass of a neutron is approximately:

    (A) 1.00866 amu

    (B) 1.00727 amu

    (C) 0.00055 amu

    (D) 4.0026 amu

72. 1 Fermi is equal to:

    (A) $10^{-15}$ m

    (B) $10^{-10}$ m

    (C) $10^{-12}$ m

    (D) $10^{-6}$ m

73. The rest mass of a photon is: [BSEB, 2017]

    (A) Zero

    (B) $1.6 \times 10^{-27}$ kg

    (C) $9.1 \times 10^{-31}$ kg

    (D) Infinite

74. Magic numbers in nuclear physics represent:

    (A) Highly unstable nuclei

    (B) Extra stable nuclei

    (C) Radioactive decay rate

    (D) Number of isotopes

75. Liquid drop model of nucleus was proposed to explain:

    (A) Radioactivity

    (B) Nuclear fission

    (C) Shell structure

    (D) Atomic spectrum

76. Binding energy per nucleon is a measure of:

    (A) Mass of nucleus

    (B) Stability of nucleus

    (C) Charge of nucleus

    (D) Size of nucleus

77. If the activity of a sample becomes 1/16 in 40 days, its half-life is:

    (A) 10 days

    (B) 20 days

    (C) 5 days

    (D) 40 days

78. Mean life $\tau$ is how many times the half-life $T_{1/2}$?

    (A) 1.44 times

    (B) 0.693 times

    (C) 2 times

    (D) Equal

79. The particle emitted along with $\beta^+$-decay is:

    (A) Neutrino

    (B) Antineutrino

    (C) Photon

    (D) Neutron

80. For which $A$ is binding energy per nucleon maximum?

    (A) $A < 20$

    (B) $A \approx 56$

    (C) $A > 200$

    (D) $A = 1$

81. $^{14}_{6}C$ and $^{14}_{7}N$ are:

    (A) Isotopes

    (B) Isobars

    (C) Isotones

    (D) Isomers

82. $^{13}_{6}C$ and $^{14}_{7}N$ are:

    (A) Isotones

    (B) Isobars

    (C) Isotopes

    (D) Mirror nuclei

83. Distance of closest approach is used to estimate:

    (A) Atomic size

    (B) Nuclear size

    (C) Speed of light

    (D) Electron charge

84. $^{60}Co$ is used in the treatment of:

    (A) Cancer

    (B) Thyroid

    (C) Heart disease

    (D) Fever

85. Which series of radioactive decay is also known as $(4n+1)$ series?

    (A) Thorium

    (B) Neptunium

    (C) Uranium

    (D) Actinium

86. Energy of thermal neutrons is about:

    (A) 0.025 eV

    (B) 1 MeV

    (C) 10 MeV

    (D) 100 eV

87. Nuclear force is a:

    (A) Short-range force

    (B) Long-range force

    (C) Inverse square law force

    (D) Electromagnetic force

88. Unit of decay constant is: [BSEB, 2023]

    (A) $s^{-1}$

    (B) $s$

    (C) $m$

    (D) $kg$

89. A radioactive nucleus emits 1 $\alpha$ and 2 $\beta$ particles. The resulting nucleus is:

    (A) Isotope of original

    (B) Isobar of original

    (C) Isotone of original

    (D) None

90. $1$ atomic mass unit is equal to:

    (A) $931.5$ MeV

    (B) $1.6$ MeV

    (C) $10.2$ eV

    (D) $0.51$ MeV

91. The volume of a nucleus is proportional to:

    (A) $R^3$

    (B) $A$

    (C) Both (A) and (B)

    (D) $Z$

92. Which particle has zero rest mass and zero charge?

    (A) Photon

    (B) Neutrino

    (C) Both (A) and (B)

    (D) Electron

93. Half-life of a substance is 20 minutes. Time to decay 75% of it:

    (A) 40 minutes

    (B) 20 minutes

    (C) 60 minutes

    (D) 10 minutes

94. The penetration of $\beta$-particles is:

    (A) More than $\alpha$ but less than $\gamma$

    (B) Less than $\alpha$

    (C) More than $\gamma$

    (D) Zero

95. $^{238}_{92}U$ has how many neutrons?

    (A) 92

    (B) 238

    (C) 146

    (D) 330

96. Which is used in dating very old rocks?

    (A) Carbon-14

    (B) Uranium-238

    (C) Iodine-131

    (D) Cobalt-60

97. The magnetic moment of a neutron is:

    (A) Zero

    (B) Negative

    (C) Positive

    (D) Infinite

98. Percentage of sample decayed after two half-lives is:

    (A) 75%

    (B) 50%

    (C) 25%

    (D) 100%

99. Specific charge of a nucleus is:

    (A) $Ze/Am_p$

    (B) $e/m$

    (C) $A/Z$

    (D) Constant

100. $1$ Rutherford (unit) is equal to:

     (A) $10^6$ disintegrations/sec

     (B) $10^3$ disintegrations/sec

     (C) $3.7 \times 10^{10}$ disintegrations/sec

     (D) 1 disintegration/sec

Topic 7: Bihar Board Previous Year Focus (PYQs)

101. The particle having same mass as electron but positive charge:

     (A) Proton

     (B) Positron

     (C) Alpha

     (D) Neutron

102. Thermal neutrons are those whose energy is equal to:

     (A) $kT$

     (B) $mc^2$

     (C) $h\nu$

     (D) $1/2 mv^2$

103. In nuclear reactor, heavy water is used as:

     (A) Moderator

     (B) Fuel

     (C) Control rod

     (D) Shielding

104. Which of the following is an electromagnetic wave? [BSEB, 2018]

     (A) $\alpha$-rays

     (B) $\beta$-rays

     (C) $\gamma$-rays

     (D) None

105. Mass number of a nucleus is: [BSEB, 2012]

     (A) Always more than atomic number

     (B) Always less than atomic number

     (C) Sometimes more and sometimes equal to atomic number

     (D) Always equal to atomic number

106. Relation between Bohr radius ($r$) and mass number ($A$):

     (A) $r \propto A^{1/3}$

     (B) $r \propto A$

     (C) $r \propto A^2$

     (D) $r \propto A^{-1}$

107. Number of neutrons in $_{13}^{27}Al$ is:

     (A) 13

     (B) 27

     (C) 14

     (D) 40

108. Which is used as a tracer in agriculture?

     (A) $P^{32}$

     (B) $U^{235}$

     (C) $C^{14}$

     (D) $Co^{60}$

109. If decay constant is $\lambda$, then mean life is: [BSEB, 2022]

     (A) $1/\lambda$

     (B) $0.693/\lambda$

     (C) $\lambda$

     (D) $\lambda^2$

110. Solar energy is mainly due to:

     (A) Fusion of Hydrogen into Helium

     (B) Fission of Uranium

     (C) Burning of gases

     (D) Fusion of Helium into Carbon

111. Radioactive elements belong to:

     (A) Unstable nuclei

     (B) Stable nuclei

     (C) Light nuclei

     (D) Gases

112. The energy released in fusion of 4 protons into 1 Helium is:

     (A) 26.7 MeV

     (B) 200 MeV

     (C) 13.6 eV

     (D) 1.6 MeV

113. Fast neutrons are slowed down by:

     (A) Elastic collisions with light nuclei

     (B) Passing through lead

     (C) Magnetic fields

     (D) Electronic excitation

114. $^{210}_{84}Po \rightarrow ^{206}_{82}Pb + X$. Here $X$ is:

     (A) Alpha particle

     (B) Beta particle

     (C) Gamma ray

     (D) Neutron

115. Atomic number of a nucleus represents:

     (A) Number of protons

     (B) Charge of nucleus

     (C) Position in periodic table

     (D) All of these

116. The density of nucleus is approximately: [BSEB, 2023]

     (A) $2.3 \times 10^{17}$ kg/m³

     (B) $1.1 \times 10^{17}$ kg/m³

     (C) $2.3 \times 10^{10}$ kg/m³

     (D) $10^5$ kg/m³

117. Binding energy of Deuteron ($^2H$) is:

     (A) 2.22 MeV

     (B) 1.11 MeV

     (C) 28.3 MeV

     (D) 7.07 MeV

118. Atomic mass is measured by:

     (A) Mass spectrograph

     (B) Screw gauge

     (C) Calorimeter

     (D) Potentiometer

119. Unit of packing fraction is:

     (A) No unit

     (B) kg

     (C) amu

     (D) MeV

120. Radioactivity is a:

     (A) Nuclear phenomenon

     (B) Atomic phenomenon

     (C) Chemical phenomenon

     (D) Thermal phenomenon

121. The most penetrating radiation among the following is: [BSEB, 2024]

     (A) $\gamma$-rays

     (B) $\beta$-rays

     (C) $\alpha$-rays

     (D) X-rays

122. Half-life and mean life are related as:

     (A) $T_{1/2} = 0.693 \tau$

     (B) $\tau = 0.693 T_{1/2}$

     (C) $T_{1/2} = \tau$

     (D) $T_{1/2} = 1.44 \tau$

123. During $\beta^-$ decay, a neutron is converted into:

     (A) Proton + electron + antineutrino

     (B) Proton + positron + neutrino

     (C) Only proton

     (D) Alpha particle

124. Which of the following is not a nucleon?

     (A) Proton

     (B) Neutron

     (C) Electron

     (D) None

125. The ratio of radii of nuclei with $A=1$ and $A=27$:

     (A) 1:3

     (B) 1:9

     (C) 3:1

     (D) 1:27

126. If $N_0$ is initial amount, amount left after $n$ half-lives: [BSEB, 2021]

     (A) $N_0 (1/2)^n$

     (B) $N_0 / n$

     (C) $N_0 \times n$

     (D) $N_0 – n$

127. Which is used as a coolant?

     (A) Liquid Sodium

     (B) Heavy water

     (C) Air

     (D) All of these

128. Nuclear fission was discovered by:

     (A) Hahn and Strassmann

     (B) Fermi

     (C) Curie

     (D) Bohr

129. The range of $\alpha$-particles in air is:

     (A) Very small (cms)

     (B) Very large (kms)

     (C) Zero

     (D) Infinite

130. Nuclear reactor works on:

     (A) Controlled chain reaction

     (B) Uncontrolled chain reaction

     (C) Spontaneous reaction

     (D) Chemical reaction

131. In $\beta^+$ decay, atomic number:

     (A) Decreases by 1

     (B) Increases by 1

     (C) Remains same

     (D) Decreases by 2

132. Mass defect per nucleon is:

     (A) Packing fraction

     (B) Binding energy

     (C) Decay constant

     (D) Activity

133. Binding energy curve helps to explain:

     (A) Fission and Fusion

     (B) Atomic spectra

     (C) Magnetic properties

     (D) Conductivity

134. Unit of Decay Constant $\lambda$ is: [BSEB, 2023]

     (A) $s^{-1}$

     (B) $m$

     (C) $s$

     (D) $J$

135. Mirror nuclei have:

     (A) Same $A$ but $Z$ and $N$ interchanged

     (B) Same $Z$

     (C) Same $N$

     (D) Same chemistry

136. Particle having zero rest mass: [BSEB, 2017]

     (A) Photon

     (B) Electron

     (C) Proton

     (D) Alpha

137. 1 amu is equivalent to:

     (A) $1.66 \times 10^{-27}$ kg

     (B) $1.66 \times 10^{-24}$ kg

     (C) Both (A) and (B)

     (D) $10^{-31}$ kg

138. Binding energy of $^{4}He$ is approximately:

     (A) 28.3 MeV

     (B) 7.07 MeV

     (C) 1.1 MeV

     (D) 100 MeV

139. If $T_{1/2} = 1580$ years, its mean life is:

     (A) 2278 years

     (B) 1580 years

     (C) 1000 years

     (D) 3160 years

140. Nuclear reactor control rods absorb:

     (A) Neutrons

     (B) Protons

     (C) Electrons

     (D) Energy

141. Shape of nucleus is generally:

     (A) Spherical

     (B) Cylindrical

     (C) Disc-like

     (D) Flat

142. Nuclear force is charge independent:

     (A) True

     (B) False

     (C) Only for heavy nuclei

     (D) Only for $n-n$

143. Which series is $(4n)$ series?

     (A) Thorium

     (B) Neptunium

     (C) Uranium

     (D) Actinium

144. $H_\alpha$ line of hydrogen spectrum relates to:

     (A) Atom (not Nuclei)

     (B) Nuclei

     (C) Fusion

     (D) Fission

145. One Bequerel is equal to:

     (A) 1 disintegration/sec

     (B) $3.7 \times 10^{10}$ dps

     (C) $10^6$ dps

     (D) 0

146. K-capture occurs in:

     (A) Nuclei with excess protons

     (B) Nuclei with excess neutrons

     (C) All nuclei

     (D) Stable nuclei

147. Neutrino has:

     (A) Spin 1/2

     (B) No charge

     (C) Almost zero mass

     (D) All of these

148. Average binding energy per nucleon is about:

     (A) 8 MeV

     (B) 13.6 eV

     (C) 1.6 MeV

     (D) 100 MeV

149. Moderator for fast neutrons should be:

     (A) Light nuclei

     (B) Heavy nuclei

     (C) Liquid oxygen

     (D) Lead

150. Total number of nucleons in $_{92}^{238}U$ is:

     (A) 238

     (B) 92

     (C) 146

     (D) 330