Nuclear Power Engineering MCQs : This section focuses on the "Nuclear Power Engineering". These Multiple Choice Questions (MCQs) should be practiced to improve the Nuclear Power Engineering skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
"Critical mass" is the minimum mass of nuclear fissile material required for the
A. sustainment of chain reaction.
B. power generation on commercial scale.
C. economic power generation.
D. none of these.
Question 2
A boiling water reactor is the one, in which the
A. coolant water is allowed to boil in the core of the reactor.
B. coolant water, after being heated in the reactor core, generates steam in a boiler.
C. pressurised water is pumped into the core.
D. fuel and the coolant are thoroughly mixed to form a homogeneous solution.
Question 3
A homogeneous reactor is the one, in which the
A. fissile atoms are evenly distributed throughout the mass of nuclear reactor.
B. same substance (e.g. heavy water) is used as moderator & coolant.
C. the fuel and the moderator is mixed to form a homogeneous material.
D. all (a), (b) and (c).
Question 4
A nuclear reactor can't be used for
A. the production of radioisotopes.
B. supplying intense fields or beams of neutron for scientific experiments.
C. marine ship propulsion.
D. none of these.
Question 5
An electron has a mass that is approximately __________ that of the proton.
A. 1836 (approximately)
B. 1/1836 (approximately)
C. 1
D. ∞
Question 6
Commercial power generation from fusion reactor is not yet possible, because
A. it is difficult to control fusion reaction.
B. the fuel required (e.g. deuterium and tritium) is scarce.
C. it is difficult to initiate fusion reaction.
D. quantity of fuel required for initiating fusion reaction is prohibitively high.
Question 7
Energy equivlant to one atomic mass unit (amu) is __________ MeV.
A. 9.31
B. 93.1
C. 931
D. 9310
Question 8
Fast breeder reactors do not
A. use Th-232 as fissile fuel.
B. convert fertile material to fissile material.
C. use fast neutrons for fission.
D. use molten sodium as coolant.
Question 9
Fast breeder Test Reactor (FBTR) is located at
A. Kalpakkam (near Madras).
B. Kota (in Rajasthan).
C. BARC (Trombay).
D. Tarapur (in Maharashtra).
Question 10
Final product of uranium extraction plant at Jadugoda (Bihar) is
A. uranium
B. uranium oxide
C. uranium carbide
D. magnesium diuranate
Question 11
Fission of U-235 on slow neutron bombardment can be represented by
A. 92U235 + 3 γ1 56Ba143 + 36Kr90
B. 92U235 + 0n1 56Ba143 + 36Kr90 + 3 0n1
C. 92U235 + 0n1 56Ba143 + 36Kr90 + 3 0n1 + Q (energy)
D. 92U235 + 0n1 92U236 + 30n1+ Q (energy)
Question 12
Gas cooling as compared to water cooling of nuclear reactors
A. can not attain a high temperature.
B. is more efficient as gas has a higher specific heat.
C. can produce only saturated steam for feeding to power turbine.
D. none of these.
Question 13
Heat is generated in a nuclear reactor (thermal) by
A. combustion of a nuclear fuel e.g. uranium.
B. fusion of atoms of uranium.
C. absorption of neutrons in uranium atoms.
D. fission of U-235 by neutrons.
Question 14
Hydrogen bomb employs the nuclear fusion of
A. hydrogen
B. deuterium
C. tritium
D. helium
Question 15
Hydrogen has __________ isotopes.
A. no
B. one
C. two
D. three
Question 16
In a nuclear explosion, the energy is released primarily in the form of __________ energy-
A. potential
B. thermal
C. kinetic
D. electrical
Question 17
MeV is the unit of
A. radioactivity
B. energy
C. potential difference
D. none of these
Question 18
Moderating material used in a thermal-reactor should be a
A. good absorber of neutrons.
B. solid substance.
C. poor absorber of neutrons.
D. none of these.
Question 19
Molten sodium (as a coolant in fast breeder reactor)
A. can't attain high temperature at normal pressure.
B. is not at all corrosive, even at a higher temperature.
C. is highly radioactive at elevated temperatures and can cause explosion, when it comes in contact with air or water.
D. none of these
Question 20
One 'amu' is equivalent to
A. 9.31 MeV
B. 931 eV
C. 931 Mev
D. 931J
Question 21
Ordinary water is not used as a moderator because, it
A. has a low absorption cross-section.
B. has a low scattering cross-section.
C. absorbs neutrons.
D. does not absorb neutrons.
Question 22
Out of the followingplaces, a nuclear power plant is not located at
A. Talcher (Orissa)
B. Kaiga (Karnataka)
C. Rawatbhata (Rajsthan)
D. Kalpakkam (Tamilnadu)
Question 23
Research reactors are normally meant for
A. producing high neutron flux 1012-1013 neutrons/cm2, sec and studying the effect of neutron bombardment on dif ferent materials.
B. accelerating the neutrons.
C. power generation.
D. none of these
Question 24
Sodium melts (at atmospheric pressure) at a temperature of __________ °C.
A. 58
B. 98
C. 348
D. 588
Question 25
Spent fuel from the nuclear thermal reactor contains
A. fission products
B. plutonium
C. unused fuel
D. all (a), (b) & (c)
Question 26
Tarapur atomic power station
A. has two boiling water reactors of American design.
B. has an installed capacity of 400 MW.
C. is the first power reactor in India, which became critical in 1969.
D. all (a), (b) and (c).
Question 27
The amount of a radioactive material (having a half life of 100 years) remaining after 400 years will be __________ of its original weight.
A. 01-Feb
B. 01-Apr
C. 01-Aug
D. Jan-16
Question 28
The amount of a radioisotope remaining undecayed after a time equal to four times its half life, will be __________ percent.
A. 3.125
B. 6.25
C. 12.5
D. 25
Question 29
The atomic number of a radioactive element is not changed, when it emits __________ rays.
A. α
B. β
C. γ
D. α & β
Question 30
The atomic number of an element is equal to the number of __________ present in its atom.
A. neutrons
B. electrons
C. protons
D. either (b) or (c)
Question 31
The decay product of tritium (a beta emitter) is
A. lithium
B. helium
C. deuterium
D. hydrogen
Question 32
The decrease in the atomic number is not observed in case of
A. electron capture
B. β-emission
C. α-emission
D. positron emission
Question 33
The largest stable nucleus is
A. U-235
B. U-238
C. Pb-206
D. Bi-209
Question 34
The mass number of an element is not changed, when it emits __________ radiations.
A. α & β
B. β & γ
C. γ & α
D. α, β, & γ
Question 35
The ratio of volume of an atom to that of its nucleus is
A. 1012
B. 10-Dec
C. 10-Aug
D. 108
Question 36
The second underground nuclear test was conducted by India at
A. Jaisalmer
B. Pokhran
C. Kalpakkan
D. Narora
Question 37
The time taken for a radioactive element to reduce to 50% of its original weight is __________ years, if its half life period is 12 years.
A. 24
B. 18
C. 6
D. 36
Question 38
The type of pump used for the recirculation of molten sodium coolant in liquid metal cooled reactor is a/an __________ pump.
A. electromagnetic
B. reciprocating
C. centrifugal
D. volute
Question 39
Thorium-232 is converted into uranium-233 in a/an __________ nuclear reactor.
A. thermal
B. fast breeder
C. heavy water moderated
D. enriched uranium
Question 40
Velocity of the thermal neutron (< 0.025 eV) used for fission of U-235 is around __________ m/sec.
A. 1
B. 2200
C. 3 x 1011
D. 9 x 1021
Question 41
Which is the most commonly used molten metal for cooling of nuclear reactors ?
A. Calcium
B. Sodium
C. Mercury
D. Zinc
Question 42
Which is used as a coolant in nuclear reactor due to its high capture cross-section ?
A. H2
B. N2
C. He
D. CO2
Question 43
Which of the following is not a naturally occurring nuclear fuel ?
A. Uranium-238
B. Thorium-233
C. Plutonium-239
D. None of these
Question 44
Which of the following is a moderating material used in nuclear reactor ?
A. Graphite.
B. Cadmium.
C. Zircalloy (an alloy of zirconium and aluminium).
D. Stainless steel.
Question 45
Which of the following is artificially produced as it does not occur in nature ?
A. Uranium-235
B. Uranium-233
C. Plutonium-239
D. Both (b) and (c)
Question 46
Which of the following is not, a fertile material ?
A. Th-232
B. U-238
C. U-233
D. none of these
Question 47
Which of the following may be used to measure the rate of nuclear disintegration?
A. Geiger-Muller Counter
B. Cyclotron
C. Cold chamber
D. Mass spectrograph
Question 48
Which of the following may not need a control rod ?
A. Liquid metal cooled reactor.
B. Fast breeder reactor.
C. Candu reactor.
D. None of these.
Question 49
Which of the following may not need a moderator ?
A. Candu reactor
B. Fast breeder reactor
C. Homogeneous reactor
D. Pressurised water reactor
Question 50
Which one is the radioactive isotope of hydrogen ?
A. Deuterium
B. Ortho-hydrogen
C. Tritium
D. None of these
Question 51
Which of the following gases has very high neutron capture cross-section, making it unsuitable as a coolant in nuclear reactor?
A. N₂
B. He
C. CO₂
D. H₂
Question 52
Heavy water (D₂O) in a nuclear reactor serves as a
A. Coolant
B. Moderator
C. Both A & B
D. Neutron absorber
Question 53
Moderating material used in a thermal-reactor should be a
A. Good absorber of neutrons
B. Solid substance
C. Poor absorber of neutrons
D. None of these
Question 54
The 92U238 emits an a-particle. The product is
A. 90U234
B. 90U238
C. 90U236
D. 92U236
Question 55
__________ have the same mass number, but different nuclear charge.
A. Isotopes
B. Isobars
C. Isotones
D. None of these
Question 56
Water is a better coolant than a gas (like CO₂, He, N₂ etc.), because it
A. Is a better neutron moderator as well
B. Requires comparatively smaller pumps and heat exchanger for a given heat transfer rate
C. Has a better heat transfer characteristics, and it can be pressurised to attain a high temperature
D. All of the above
Question 57
Which is the most commonly used molten metal for cooling of nuclear reactors?
A. Calcium
B. Sodium
C. Mercury
D. Zinc
Question 58
Radioactive decay is a __________ change.
A. Chemical
B. Nuclear
C. Physical
D. None of these
Question 59
Heavy water used in the nuclear reactors to slow down the speed of neutrons is
A. Highly purified water
B. A compound of oxygen and deuterium
C. Water having dissolved salts of heavy metals
D. None of these
Question 60
Use of molten metal as a coolant in fast breeder reactor helps in
A. Rapid heat transfer from the core
B. Accelerating the reaction rate in the core
C. Breeding neutrons
D. Accelerating the neutrons
Question 61
Fuel for a fast breeder reactor is
A. Plutonium
B. Uranium
C. Radium
D. Neptunium
Question 62
Uranium is recovered from its ore (pitchblende) by
A. Froth floatation technique
B. Leaching with sulphuric acid
C. Smelting in a furnace
D. Dissolving in water
Question 63
Which of the following is the most harmful for the human being?
A. Β-rays
B. X-rays
C. Γ-rays
D. Ultra violet rays
Question 64
Coolant used in a boiling water reactor is
A. Hydrogen gas
B. Water
C. Steam
D. A mixture of water & steam
Question 65
The atomic weight and atomic number of an element are A and Z respectively. What is the number of neutrons in the atom of that element?
A. A+Z
B. A- Z
C. A
D. Z
Question 66
Extraction of uranium from its ore is done by __________ method.
A. Chemical
B. Pyrometallurgical
C. Physical beneficiation
D. Electrometallurgical
Question 67
Graphite is used in nuclear reactor as
A. Insulation lining of the reactor
B. Fuel
C. Lubricant
D. Retarder of neutron velocity
Question 68
The most abundant isotope of natural uranium is
A. 92U238
B. 92U235
C. 92U234
D. None of these
Question 69
Which of the following is artificially produced as it does not occur in nature?
A. Uranium⁻²35
B. Uranium⁻²33
C. Plutonium⁻²39
D. Both B and C
Question 70
Function of control rod in a nuclear reactor is to control
A. Temperature
B. Pressure
C. Fuel consumption
D. Absorption of neutrons
Question 71
Atoms with same number of neutrons, but different number of nucleons are called
A. Isotones
B. Isobars
C. Isotopes
D. Isoters
Question 72
The mass number of an element is equal to the number of __________ in the nucleus.
A. Electrons
B. Neutrons
C. Protons
D. Neutrons plus protons (i.e., nucleons)
Question 73
Radioactivity of an isotope is expressed in
A. Barn
B. MeV
C. Curie
D. Ergs
Question 74
Nuclear power plant is not located at
A. Talcher (Orissa)
B. Rawatbhata (Rajasthan)
C. Kalpakkam (Tamilnadu)
D. Kaiga (Karnataka)
Question 75
The disintegration rate of a radioactive element
A. Progressively increases
B. Progressively decreases
C. Remains constant throughout
D. May increase or decrease depending on the material
Question 76
When the difference between mass number and atomic number of atoms of two or more elements are same, the atoms are termed as
A. Isomers
B. Isotopes
C. Isobars
D. Isotones
Question 77
An element having large number of __________ is most easily subjected to nuclear fission.
A. Protons
B. Electrons
C. Neutrons
D. Nucleons
Question 78
Which of the following accounts for the maximum energy release in the nuclear fission process?
A. Kinetic energy of fission products
B. Radioactive decay of fission products
C. Instantaneous release of γ-rays
D. Kinetic energy of neutrons
Question 79
The emission of an a-particle causes the resultant nucleus to have
A. More atomic weight and less atomic number
B. Less atomic weight and less atomic number
C. Less atomic weight and more atomic number
D. None of these
Question 80
The radioisotope used to study the thyroid gland is
A. Iodine
B. Cobalt
C. Iron
D. Carbon
Question 81
Percentage of the heavy water in ordi water is around
A. 0.015
B. 7.54
C. 0.71
D. 32.97
Question 82
Heavy water plant is not located at
A. Talcher
B. Tuticorin
C. Ramagundam
D. Kota
Question 83
Out of the following places, heavy water plant is not located at
A. Baroda
B. Ramagundam
C. Talcher
D. Tuticorin
Question 84
Heavy water plant is not located at
A. Kota and Baroda
B. Talcher (Orissa)
C. Tuticorin(Tamilnadu)
D. Korba
Question 85
Absorption/scattering cross-section of an element is expressed in "barn", which is equivalent to
A. 10⁻²⁴ cm²
B. 10⁻¹² cm
C. 1 Angstrom
D. 10⁻²⁴ cm
Question 86
U-235 content in enriched uranium, that is normally used in power reactors (e.g., at Tarapur atomic power plant), is about __________ percent.
A. 85
B. 50
C. 3
D. 97
Question 87
Thorium⁻²32 (a fertile material) on absorption of a neutron gets converted into __________ , which is a fissile material.
A. Thorium⁻²33
B. Uranium⁻²35
C. Uranium⁻²33
D. Plutonium⁻²39
Question 88
In the nuclear reaction, 93N239 → 93Pu239 + ?; the missing particle is a/an
A. Electron
B. Proton
C. Neutron
D. Position
Question 89
Enrichment of uranium is done to increase the concentration of __________ in the natural uranium.
A. U-238
B. U-233
C. U-235
D. Pu-239
Question 90
The amount of a radioactive material (having a half life of 100 years) remaining after 400 years will be __________ of its original weight.
A. 1-2
B. 1-4
C. 1-8
D. 1-16
Question 91
Biological shield is provided in a nuclear power reactor to protect the __________ from radiation damage.
A. Fuel elements
B. Operating personnels
C. Walls of the reactor
D. None of these
Question 92
In nuclear reactions, __________ number is conserved.
A. Mass
B. Atomic
C. Both A & B
D. Neither A nor B
Question 93
The atomic number of an element is equal to the number of __________ present in its atom.
A. Neutrons
B. Electrons
C. Protons
D. Either B or C
Question 94
In a homogeneous nuclear reactor, the __________ are mixed together.
A. Fuel & coolant
B. Fuel & moderator
C. Coolant & moderator
D. None of these
Question 95
Nucleus of 92U235 contains __________ protons.
A. 92
B. 235
C. 143
D. 325
Question 96
Thermal neutrons which are used to cause the fission of U-235 have energy __________ eV.
A. < 0.025
B. > 1
C. 1-25
D. > 200
Question 97
Primary purpose of a __________ nuclear reactor is to supply a high neutron flux of the order of 10¹³ to 10¹⁴ neutrons/cm² second.
A. Research
B. Power
C. Breeder
D. Homogeneous
Question 98
Velocity of the thermal neutron (< 0.025 eV) used for fission of U-235 is around __________ m/sec.
A. 1
B. 2200
C. 3 x 10¹¹
D. 9 x 10²¹
Question 99
Atoms of U-238 and U-235 differ in structure by three
A. Electrons and three protons
B. Protons
C. Neutrons
D. Electrons
Question 100
Percentage of U-238 in natural uranium is around
A. 0.71
B. 99.29
C. 0.015
D. 29.71
Question 101
Candu reactor is a __________ nuclcear reactor.
A. Natural uranium fuelled heavy water cooled & moderated
B. Highly enriched uranium (85% U-235) fuelled
C. Homogeneous
D. Fast breeder
Question 102
A control rod
A. Should have small absorption cross-section
B. Is generally made of boron, hafnium or cadmium
C. Should have large absorption cross-section
D. Both B and C
Question 103
A fast breeder reactor
A. Utilises fast neutrons for causing fission
B. Converts fertile material (e.g., U-238) into fissile material (Pu-239)
C. Normally employs molten sodium as coolant
D. All of the above
Question 104
Heat is generated in a nuclear reactor (thermal) by
A. Combustion of a nuclear fuel e.g. uranium
B. Fusion of atoms of uranium
C. Absorption of neutrons in uranium atoms
D. Fission of U-235 by neutrons
Question 105
Fuel for a nuclear reactor (thermal) is
A. Uranium
B. Plutonium
C. Radium
D. None of these
Question 106
β-rays emission in radioactive disintegration is always accompanied by the emission of
A. γ-rays
B. α-rays
C. Neutrons
D. None of these
Question 107
A radioactive substance does not emit
A. Α-ray
B. Proton
C. Position
D. Β-ray
Question 108
A boiling water reactor is the one, in which the
A. Coolant water is allowed to boil in the core of the reactor
B. Coolant water, after being heated in the reactor core, generates steam in a boiler
C. Pressurised water is pumped into the core
D. Fuel and the coolant are thoroughly mixed to form a homogeneous solution
Question 109
A homogeneous reactor is the one, in which the
A. Fissile atoms are evenly distributed throughout the mass of nuclear reactor
B. Same substance (e.g. heavy water) is used as moderator & coolant
C. The fuel and the moderator is mixed to form a homogeneous material
D. All of the above
Question 110
The phenomenon of radioactivity was discovered by
A. Madam Curie
B. Bacquerrel
C. Roentgen
D. J.J. Thomson
Question 111
Fast breeder test reactor at Kalpakkam is designed for using
A. Thorium as a fertile material
B. U-238 as a fertile material
C. Helium as a coolant
D. Uranium ore directly as a fuel
Question 112
Thorium⁻²32 is converted into uranium⁻²33 in a/an __________ nuclear reactor.
A. Thermal
B. Fast breeder
C. Heavy water moderated
D. Enriched uranium
Question 113
The size of an atom is of the order of one
A. °Angstrom
B. Fermi
C. Micron
D. Mm
Question 114
A thermal nuclear reactor compared to a fast breeder reactor
A. Uses slower neutrons for fission
B. Uses faster neutrons for fission
C. Gives higher power density
D. Requires less fuel to run at the same power level
Question 115
Heavy water is preferred over ordinary water as a coolant, because it.
A. Acts both as an efficient coolant as well as a moderator
B. Can be heated to a higher temperature without pressurizing
C. Is less prone to radiation damage
D. All of the above
Question 116
Pressure in a Pressurised Water Reactor (PWR) is used for
A. Maintaining constant pressure in the primary cooling circuit under varying loads
B. Superheating the steam
C. Pressurising the water in the primary coolant circuit
D. None of these
Question 117
The ratio of volume of an atom to that of its nucleus is
A. 10¹²
B. 10⁻¹²
C. 10⁻⁸
D. 10⁸
Question 118
The function of moderators in nuclear reactor is to
A. Slow down the secondary neutrons
B. Absorb the secondary neutrons
C. Control the chain reaction
D. None of these
Question 119
Which of the following ores contains maximum percentage of uranium?
A. Carnotite
B. Thorium
C. Rescolite
D. Pitchblende
Question 120
Fission of U-235 on slow neutron bombardment can be represented by
A. 92U235 + 0n1 → 56Ba143 + 36Kr90
B. 92U235 + 0n1 → 56Ba143 + 36Kr90 + 3 0n1
C. 92U235 + 0n1 → 56Ba143 + 36Kr90 + 3 0n1 + Q (energy)
D. 92U235 + 0n1 → 92U236 + 3 0n1+ Q (energy)
Question 121
The critical mass of a fissionable material can be reduced by
A. Heating it
B. Cooling it
C. Surrounding it by neutron reflecting material
D. Surrounding it by neutron absorbing material
Question 122
Nuclear fuel usually used in a Boiling Water Reactor (BWR) is
A. Plutonium
B. Enriched uranium
C. Natural uranium
D. Thorium
Question 123
Number of secondary neutron emitted on fission of an atom of U-235 by slow neutron bombardment is
A. 3
B. 235
C. 200
D. 92
Question 124
Pick out the correct statement.
A. Positron is the antiparticle of electron
B. In α-decay, the ratio of neutron to proton decreases
C. Ionising power of β-rays is higher than that of α-rays
D. Speed of α-rays is more than that of γ-rays
Question 125
Which of the following is present in Bhabha Atomic Research Centre (BARC) complex, Trombay (Bombay)?
A. Power reactor
B. Research reactor
C. Fast breeder reactor
D. Heavy water plant
Question 126
Safety rods provided in nuclear reactors to guard against accidents, in case of earthquake are made of
A. High carbon steel
B. Molybdenum
C. Zircalloy
D. Boron or cadmium
Question 127
Which of the following is not used as a nuclear fuel cladding material?
A. Zircalloy
B. Cadmium
C. Ceramics
D. Stainless steel
Question 128
Spent fuel from the nuclear thermal reactor contains
A. Fission products
B. Plutonium
C. Unused fuel
D. All of the above
Question 129
The half life period of a radioactive element depends upon the
A. Temperature
B. Pressure
C. Amount of element present
D. None of these
Question 130
Which of the following is a fuel for a fusion reactor (thermonuclear reactor)?
A. Deuterium and tritium
B. U-233
C. Thorium
D. Heavy water
Question 131
The molecular weight of heavy water is
A. 10
B. 18
C. 20
D. 36
Question 132
Bhabha Atomic Research Centre (BARC) located at Trombay (near Bombay) has
A. Five operating research reactors (namely Apsara, Cirus Zerelina, Purnima and Dhurva)
B. A 420 MW nuclear power plant
C. A very large capacity (100 tons/yr) heavy water plant
D. All of the above
Question 133
Coolant used in a fast breeder reactor is
A. Molten sodium
B. Heavy water
C. Ordinary water
D. Helium
Question 134
Ceramic nuclear metals compared to solid nuclear metals have
A. Higher melting points
B. Low strength at high temperature
C. More chances of radiation damage
D. Poorer corrosion resistance
Question 135
The time required for half of the __________ of a radioactive isotope to decay is called its half life.
A. Nuclei
B. Electrons
C. Protons
D. Neutrons
Question 136
Extraction of uranium from its ore is done using __________ methods.
A. Electrometallurgical
B. Pyrometallurgical
C. Chemical
D. Physical beneficiation
Question 137
Nuclides having the same atomic numbers are termed as
A. Isotopes
B. Isomers
C. Isotones
D. Isobars
Question 138
Emission of β-particles during radioactive decay of a substance is from
A. Innermost shell
B. Nucleus
C. Outermost shell
D. None of these
Question 139
The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then
A. 3/4th of it will disintegrate in two months
B. It will completely disintegrate in two months
C. It will completely disintegrate in four months
D. L/8th of it will remain intact at the end of four months
Question 140
Pressure of CO₂ gas (which is a coolant) in the Calder-Hall nuclear reactor is __________ kgf/cm² .
A. 0.2
B. 7
C. 35
D. 50
Question 141
Research reactors are normally meant for
A. Producing high neutron flux 10¹²-10¹³ neutrons/cm², sec and studying the effect of neutron bombardment on dif ferent materials
B. Accelerating the neutrons
C. Power generation
D. None of these
Question 142
The most commonly used nuclear fuel in boiling water reactor is
A. Enriched uranium
B. Natural uranium
C. Plutonium
D. Monazite sand
Question 143
The atomic mass of an element is fractional, because
A. Of uncertainty principle
B. It may have isobars
C. It contains neutrons
D. It may have isotopes
Question 144
Nuclear power generation capacity in India is
A. 3000 MW
B. 10000 MW
C. More than hydroelectric power generation capacity
D. More than thermal power generation capacity
Question 145
Gas cooling as compared to water cooling of nuclear reactors
A. Can not attain a high temperature
B. Is more efficient as gas has a higher specific heat
C. Can produce only saturated steam for feeding to power turbine
D. None of these
Question 146
Percentage of heavy water in ordinary water is around
A. 0.015
B. 7.54
C. 0.71
D. 32.97
Question 147
Heavy water is used as a moderator in a
A. Pressurised water reactor (PWR)
B. Boiling water reactor (BWR)
C. Candu reactor
D. Molten sodium cooled reactor
Question 148
A fertile material is the one, which can be
A. Converted into fissile material on absorption of neutron
B. Fissioned by slow (thermal) neutrons
C. Fissioned by fast neutrons
D. Fissioned by either slow or fast neutrons
Question 149
Heavy water' is termed as 'heavy' because it is
A. Denser than water
B. An oxide of deuterium
C. A heavy liquid
D. An oxide of heavier isotope of oxygen
Question 150
Isotopes of an element have the same
A. Number of neutrons
B. Mass number
C. Electronic configuration
D. Atomic weight
Question 151
Which of the following nuclear reactors is the most efficient thermodynamically while operating between the same temperature and pressure limits of the reactor?
A. Molten sodium cooled
B. CO₂ gas cooled
C. Pressurised water
D. Boiling water
Question 152
Main source of __________ is monazite sand.
A. Uranium
B. Polonium
C. Hafnium
D. Thorium
Question 153
Which one is different for the neutral atoms of the isotopes of an element?
A. Atomic weights
B. Atomic numbers
C. Number of protons
D. Number of electrons
Question 154
Energy produced in the nuclear fission is of the order of __________ MeV.
A. 20
B. 200
C. 1000
D. 2000
Question 155
Fast breeder reactors do not
A. Use Th-232 as fissile fuel
B. Convert fertile material to fissile material
C. Use fast neutrons for fission
D. Use molten sodium as coolant
Question 156
75% of a radioactive element decays in 6 hours. Its half life period is __________ hours.
A. 3-4
B. 1-6
C. 3
D. 4
Question 157
The phenomenon of nuclear fission is opposite to that of
A. Radioactive decay
B. Thermionic emission
C. Nuclear fusion
D. Combustion
Question 158
The number of neutrons accompanying the formation of 54Xe139 and 38Sr94 from the absorption of a slow neutron by 92U235 , followed by nuclear fission is
A. 1
B. 2
C. 3
D. 4
Question 159
Which of the following is not, a fertile material?
A. Th-232
B. U-238
C. U-233
D. None of these
Question 160
Which of the following may not need a control rod?
A. Liquid metal cooled reactor
B. Fast breeder reactor
C. Candu reactor
D. None of these
Question 161
Pick out the wrong statement.
A. Isotopes have the same number of protons & electrons, but different number of neutrons
B. Hydrogen has two isotopes
C. In ordinary hydrogen, 1H1 and 1H2 are present in the ratio 6400:1
D. None of these
Question 162
Thermal shield is used in high powered nuclear reactors to
A. Protect the walls of the reactor from radiation damage
B. Absorb the fast neutrons
C. Slow down the secondary neutrons
D. Protect the fuel element from coming in contact with the coolant
Question 163
Which of the following undergoes fission reaction easily?
A. U-235
B. U-238
C. Th-232
D. None of these
Question 164
H₂ is a better coolant than CO₂, due to its relatively
A. Lower density
B. Higher specific heat
C. Non-reactivity to uranium
D. Lower neutron capture cross-section
Question 165
Out of the following, nucleus of __________ atom contains the largest number of neutrons.
A. U-235
B. U-238
C. U-239
D. Pu-239
Question 166
The sum of masses of two nuclei produced in nuclear fission compared to the mass of original nucleus is
A. Less
B. More
C. Same
D. Much more
Question 167
Pick out the correct statement.
A. Loss of electrons from neutral atoms produces negative ions
B. The radius of nucleus & atomic size are of the order of 10⁻¹² cm & 10⁻⁸ cm respectively
C. Gain of electrons by neutral atoms form cations
D. Proton to neutron ratio in a stable nucleus is 2 : 1
Question 168
Heavy water has maximum density at __________ °C.
A. 4
B. 11.6
C. 0
D. 18.6
Question 169
How many atoms are present in one gm-atom of an element?
A. 2 x 10²³
B. 6 x 10²³
C. 6 x 10³²
D. 5 x 10?
Question 170
A heterogeneous reactor is the one, in which the moderator and the
A. Coolant are different materials
B. Coolant are present in different phases (e.g., heavy water and graphite)
C. Fuel are present in different phases (e.g. uranium and heavy water)
D. None of these
Question 171
Which of the following is not an ore of uranium?
A. Pitchblende
B. Kyanite
C. Carnotite
D. Rescolite
Question 172
Which of the following may not need a moderator?
A. Candu reactor
B. Fast breeder reactor
C. Homogeneous reactor
D. Pressurised water reactor
Question 173
Which one is the radioactive isotope of hydrogen?
A. Deuterium
B. Ortho-hydrogen
C. Tritium
D. None of these
Question 174
Artificially produced radioactive isotopes are used for
A. Power generation
B. Treatment of certain diseases
C. Initiating nuclear fission and fusion
D. All of the above
Question 175
Pick out the wrong statement.
A. The ratio of the density of the 'nucleus' to that of the 'atom' is 10¹²
B. Α-particle is identical with a doubly charged helium ion
C. The mass of deuterium atom is half that of helium atom
D. Gamma rays are high energy electrons
Question 176
Nuclear reactors are provided with shield to guard against the emission of mainly __________ rays.
A. X
B. α and β
C. Neutrons & gamma
D. Infrared
Question 177
Nucleus of tritium has __________ neutrons.
A. 1
B. 2
C. 3
D. 5
Question 178
The half life period of a radiactive element is 100 days. After 400 days, one gm of the element will be reduced to __________ gm.
A. 1-4
B. 1-8
C. 1-2
D. 1-16
Question 179
Neutrons have mass approximately equal to that of __________ atoms.
A. Hydrogen
B. Helium
C. Deuterium
D. None of these
Question 180
A nuclear reactor can't be used for
A. The production of radioisotopes
B. Supplying intense fields or beams of neutron for scientific experiments
C. Marine ship propulsion
D. None of these
Question 181
The main purpose of control rod in a nuclear reactor is to control the
A. Chain reaction and hence the power output by regulating the number of secondary neutrons causing fission
B. Emission of hazardous radiation
C. Conversion of fissile material into fertile material
D. Velocity of the secondary neutrons
Question 182
Which of the following is not used as a moderator in nuclear reactor?
A. Molten sodium
B. Light water
C. Beryllium
D. Boron hydride
Question 183
Uranium Corporation of India Limited (UCIL) engaged in the mining & concentration of uranium ore is located at
A. Alwaye (in Kerala)
B. Jadugoda (in Jharkhand)
C. Kalpakkam (in Tamilnadu)
D. Gopalpur coast (in Orissa)
Question 184
__________ gas is normally not used as a coolant in a nuclear reactor, because of its high neutron capture cross-section.
A. Nitrogen
B. Hydrogen
C. Helium
D. Carbon dioxide
Question 185
What is the average life of a radioactive atom having a 'half life period' of T?
A. 1.44 T
B. 0.144 T
C. 14.4 T
D. 2T
Question 186
Which of the following is a non-fissile material?
A. Plutonium⁻²39
B. Uranium⁻²35
C. Uranium⁻²33
D. Thorium⁻²32
Question 187
In the gaseous diffusion process of uranium enrichment, the natural uranium is converted into gaseous
A. Uranium oxide
B. Uranium hexaflouride
C. Uranium carbide
D. Uranium sulphate
Question 188
Indian monazite sand contains __________ percent thorium.
A. 10
B. 25
C. 60
D. 90
Question 189
Which of the following nuclear materials is fissile?
A. Uranium⁻²38
B. Thorium⁻²32
C. Plutonium⁻²39
D. None of these
Question 190
Light water' used as a coolant in nuclear reactor is nothing but
A. Ordinary water
B. Mildly acidic (pH = 6) water
C. Mildly alkaline (pH = 8) water
D. None of these
Question 191
The specific heats of three gaseous coolants namely H₂, He and CO₂ in the increasing order are
A. CO₂, He, H₂
B. CO₂, H₂, He
C. H₂, He, CO₂
D. H₂, CO₂, He
Question 192
The half life period of a radioactive element depends on its
A. Temperature
B. Pressure
C. Amount
D. None of these
Question 193
First experimental observation of nuclear fission was done by
A. Plane
B. Rutherford
C. Fermi
D. Hahn and Strassman
Question 194
Molten sodium (as a coolant in fast breeder reactor)
A. Can't attain high temperature at normal pressure
B. Is not at all corrosive, even at a higher temperature
C. Is highly radioactive at elevated temperatures and can cause explosion, when it comes in contact with air or water
D. None of these
Question 195
Pick out the wrong statement.
A. Α-particle emission from a radioactive element makes it electrically negative
B. Β-particle emission from a radioactive element makes it electrically positive
C. A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
D. The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
Question 196
Which of the following factors is the most important in the site selection for a nuclear power plant?
A. Absence of earthquake prone zone in nearby areas
B. Abundant availability of water
C. Remotely located from residential areas
D. Proximity to fuel source
Question 197
Which one is radioactive in nature?
A. Helium
B. Deuterium
C. Heavy hydrogen
D. Tritium
Question 198
If 4 gm of a radioisotope has a half life period of 10 days, the half life of 2 gm of the same istotope will be __________ days.
A. 5
B. 10
C. 20
D. 30
Question 199
The electric power generation cost in nuclear power plant is less than that in a coal based thermal power plant, mainly because the
A. Fuel cost per unit power generated is less
B. Thermal efficiency of the former is higher
C. Maintenance cost of the former is less
D. None of these
Question 200
Pick out the wrong statement.
A. The disintegration rate of a radioactive substance can not be increased by heating it
B. Electrons have negligible mass and unit negative change
C. Deuterium atom has one proton and two neutrons in its nucleus
D. Cadmium is capable of absorbing neutrons
Question 201
Plutonium
A. Is recovered from spent fuel from thermal nuclear reactor
B. Has much lower melting point (640°C ) compared to thorium (1690°C)
C. Both A & B
D. Neither A nor B
Question 202
Positron is a/an
A. Nucleus having two protons
B. Helium nucleus
C. Electron with positive charge
D. Nucleus with one proton and one neutron
Question 203
Which of the following types of nuclear reactors is most prone to radioactive hazards?
A. Pressurised water reactor
B. Gas cooled reactor
C. Molten sodium cooled reactor
D. Boiling water reactor
Question 204
The ratio of mass of a neutron to that of an electron is about 1839. What is the ratio of the mass of a proton to that of an electron?
A. 159
B. 1837
C. 2537
D. 10000
Question 205
Net efficiency of ordinary light water cooled nuclear reactor is about __________ percent.
A. 32
B. 52
C. 72
D. 88
Question 206
Commercial power generation from fusion reactor is not yet possible, because
A. It is difficult to control fusion reaction
B. The fuel required (e.g. deuterium and tritium) is scarce
C. It is difficult to initiate fusion reaction
D. Quantity of fuel required for initiating fusion reaction is prohibitively high
Question 207
Fast breeder reactors are most usable in India, because of our largest __________ deposits.
A. Thorium
B. Plutonium
C. Uranium
D. None of these
Question 208
The ratio of neutrons to protons of an element having a mass number and atomic number of 80 and 40 respectively is
A. 1
B. 0.5
C. 2
D. 4
Question 209
A pressurised water reactor (PWR) uses pressurised water as a
A. Coolant
B. Working fluid in power turbine
C. Moderator
D. None of these
Question 210
Nuclear fuel complex, Hyderabad is engaged in the job of
A. Manufacture of nuclear fuel elements/assemblies
B. Processing of uranium ore
C. Treatment of spent fuel
D. None of these
Question 211
Which of the following is not a naturally occurring nuclear fuel?
A. Uranium⁻²38
B. Thorium⁻²33
C. Plutonium⁻²39
D. None of these
Question 212
Enriched uranium means that, it contains
A. More than 0.71% of U-235
B. Only fertile material
C. Only fissile material
D. No impurities
Question 213
A moderator __________ the neutrons.
A. Slows down
B. Absorbs
C. Accelerates
D. Reflects
Question 214
Molten sodium is used as a coolant in a fast breeder reactor, because of its
A. Excellent moderating properties
B. Neutron breeding capability
C. Faster heat removal capability from the core
D. Capability to increase the reaction rate in the core
Question 215
Uranium ore is currently mined & concentrated at
A. Jadugoda
B. Ghatsila
C. Khetri
D. Alwaye
Question 216
Which of the following is a moderating material used in nuclear reactor?
A. Graphite
B. Cadmium
C. Zircalloy (an alloy of zirconium and aluminium)
D. Stainless steel
Question 217
In a pressurised water reactor (PWR), the
A. Fuel is natural uranium and heavy water acts both as moderator & coolant
B. Coolant water boils in the core of the reactor
C. Coolant water is pressurised to prevent bulk boiling of water in the core
D. Use of moderator is not required
Question 218
Hydrogen differs from deuterium in __________ properties.
A. Radioactive
B. Physical
C. Chemical
D. All of the above
Question 219
Which of the following reactors is operated at high neutron flux and low power level?
A. Breeder reactor
B. Research reactor
C. Heterogeneous reactor
D. Liquid metal (e.g., molten sodium) cooled reactor
Question 220
Radioactive decay of a material involves a __________ order reaction.
A. Third
B. Second
C. First
D. Zero
Question 221
Which is used as a coolant in nuclear reactor due to its high capture cross-section?
A. H₂
B. N₂
C. He
D. CO₂
Question 222
Isotopes of an element have different
A. Mass number
B. Electronic configuration
C. Nuclear charge
D. Chemical properties
Question 223
Liquid metal (e.g, . molten sodium) is preferred as a coolant in case of a/an __________ reactor.
A. Homogeneous
B. Graphite moderated
C. Fast breeder
D. Enriched uranium (3% U-235) fuelled
Question 224
Ordinary water is not used as a moderator because, it
A. Has a low absorption cross-section
B. Has a low scattering cross-section
C. Absorbs neutrons
D. Does not absorb neutrons
Question 225
Pick out the wrong statement.
A. Atoms with same number of nucleons but different number of protons are called isobars
B. Atoms with same number of protons but different number of nucleons are called isoters
C. Out of α, β, and γ-rays, the one having maximum penetration power are γ-rays
D. The product formed by emission of α-particle has mass number less by 4 units than the parent nuclide
Question 226
__________ moderator is used in a fast breeder reactor.
A. Graphite
B. Heavy water
C. Beryllium
D. No
Question 227
Critical mass is the minimum mass of nuclear fissile material required for the
A. Sustainment of chain reaction
B. Power generation on commercial scale
C. Economic power generation
D. None of these
Question 228
Mass of a positron is same as that of a/an
A. Electron
B. α-particle
C. Proton
D. Neutron
Question 229
__________ nuclear reactor does not require a heat exchanger to supply steam to power turbine.
A. Molten sodium cooled
B. Helium cooled
C. Boiling water
D. Pressurised water
Question 230
Which is not a fissile nuclear material?
A. U-233
B. U-235
C. U-238
D. Pu-239
Question 231
Which of the following is not a good moderating material?
A. Concrete
B. Boron
C. 18/8 stainless steel
D. All of the above
Question 232
Thermal nuclear reactors using enriched uranium as fuel contains a maximum of __________ percent fissile material i.e. U-235.
A. 1
B. 2
C. 3
D. 7
Question 233
An ideal coolant for a nuclear reactor should
A. Be a good absorber of neutrons
B. Be capable of attaining high temperature, only when it is pressurised
C. Have high density, but low heat transfer co-efficient
D. Be free from radiation damage and non-corrosive
Question 234
Which of the following isotopes is not present in natural uranium?
A. U-238
B. U-234
C. U-235
D. U-232
Question 235
Which of the following radiations is the least penetrating?
A. α-rays
B. β-rays
C. γ-rays
D. X-rays
Question 236
Secondary cooling circuit is a must in molten sodium cooled fast breeder reactor for
A. Achieving high degree of superheat in the steam
B. Faster heat removal rate from the core
C. Lowering the coolant circulation pressure
D. Avoiding the mixing of water with radioactive sodium, as it may cause explosion