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Nuclear Power Engineering MCQ Questions & Answers

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

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

View Answer

Question 2

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

View Answer

Question 3

Radioactive decay is a __________ change.

A. Chemical
B. Nuclear
C. Physical
D. None of these

View Answer

Question 4

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

View Answer

Question 5

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

View Answer

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.

View Answer

Question 7

The size of an atom is of the order of one

A. °Angstrom
B. Fermi
C. Micron
D. Mm

View Answer

Question 8

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

View Answer

Question 9

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.

View Answer

Question 10

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

View Answer

Question 11

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

View Answer

Question 12

Which of the following is not used as a nuclear fuel cladding material?

A. Zircalloy
B. Cadmium
C. Ceramics
D. Stainless steel

View Answer

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

View Answer

Question 14

First experimental observation of nuclear fission was done by

A. Plane
B. Rutherford
C. Fermi
D. Hahn and Strassman

View Answer

Question 15

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

View Answer

Question 16

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.

View Answer

Question 17

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

View Answer

Question 18

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

View Answer

Question 19

Indian monazite sand contains __________ percent thorium.

A. 10
B. 25
C. 60
D. 90

View Answer

Question 20

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

View Answer

Question 21

Which of the following may not need a moderator?

A. Candu reactor
B. Fast breeder reactor
C. Homogeneous reactor
D. Pressurised water reactor

View Answer

Question 22

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

View Answer

Question 23

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

View Answer

Question 24

The most commonly used nuclear fuel in boiling water reactor is

A. Enriched uranium
B. Natural uranium
C. Plutonium
D. Monazite sand

View Answer

Question 25

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

View Answer

Question 26

Which is not a fissile nuclear material?

A. U-233
B. U-235
C. U-238
D. Pu-239

View Answer

Question 27

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

View Answer

Question 28

Heavy water plant is not located at

A. Kota and Baroda
B. Talcher (Orissa)
C. Tuticorin(Tamilnadu)
D. Korba

View Answer

Question 29

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

View Answer

Question 30

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).

View Answer

Question 31

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

View Answer

Question 32

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

View Answer

Question 33

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)

View Answer

Question 34

In a homogeneous nuclear reactor, the __________ are mixed together.

A. Fuel & coolant
B. Fuel & moderator
C. Coolant & moderator
D. None of these

View Answer

Question 35

Which of the following is not, a fertile material ?

A. Th-232
B. U-238
C. U-233
D. none of these

View Answer

Question 36

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

View Answer

Question 37

Which of the following ores contains maximum percentage of uranium?

A. Carnotite
B. Thorium
C. Rescolite
D. Pitchblende

View Answer

Question 38

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

View Answer

Question 39

Percentage of heavy water in ordinary water is around

A. 0.015
B. 7.54
C. 0.71
D. 32.97

View Answer

Question 40

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)

View Answer

Question 41

Nucleus of tritium has __________ neutrons.

A. 1
B. 2
C. 3
D. 5

View Answer

Question 42

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.

View Answer

Question 43

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

View Answer

Question 44

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

View Answer

Question 45

Coolant used in a boiling water reactor is

A. Hydrogen gas
B. Water
C. Steam
D. A mixture of water & steam

View Answer

Question 46

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

View Answer

Question 47

Coolant used in a fast breeder reactor is

A. Molten sodium
B. Heavy water
C. Ordinary water
D. Helium

View Answer

Question 48

Which of the following isotopes is not present in natural uranium?

A. U-238
B. U-234
C. U-235
D. U-232

View Answer

Question 49

Sodium melts (at atmospheric pressure) at a temperature of __________ °C.

A. 58
B. 98
C. 348
D. 588

View Answer

Question 50

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

View Answer

Question 51

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

View Answer

Question 52

Which of the following is not an ore of uranium?

A. Pitchblende
B. Kyanite
C. Carnotite
D. Rescolite

View Answer

Question 53

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.

View Answer

Question 54

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

View Answer

Question 55

Which one is the radioactive isotope of hydrogen ?

A. Deuterium
B. Ortho-hydrogen
C. Tritium
D. None of these

View Answer

Question 56

Thorium-232 is converted into uranium-233 in a/an __________ nuclear reactor.

A. thermal
B. fast breeder
C. heavy water moderated
D. enriched uranium

View Answer

Question 57

Radioactive decay of a material involves a __________ order reaction.

A. Third
B. Second
C. First
D. Zero

View Answer

Question 58

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

View Answer

Question 59

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

View Answer

Question 60

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.

View Answer

Question 61

Heavy water plant is not located at

A. Talcher
B. Tuticorin
C. Ramagundam
D. Kota

View Answer

Question 62

Fast breeder reactors are most usable in India, because of our largest __________ deposits.

A. Thorium
B. Plutonium
C. Uranium
D. None of these

View Answer

Question 63

__________ 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

View Answer

Question 64

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

View Answer

Question 65

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

View Answer

Question 66

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)

View Answer

Question 67

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)

View Answer

Question 68

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

View Answer

Question 69

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)

View Answer

Question 70

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).

View Answer

Question 71

Which of the following is not a naturally occurring nuclear fuel?

A. Uranium⁻²38
B. Thorium⁻²33
C. Plutonium⁻²39
D. None of these

View Answer

Question 72

Hydrogen differs from deuterium in __________ properties.

A. Radioactive
B. Physical
C. Chemical
D. All of the above

View Answer

Question 73

Energy produced in the nuclear fission is of the order of __________ MeV.

A. 20
B. 200
C. 1000
D. 2000

View Answer

Question 74

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

View Answer

Question 75

Percentage of U-238 in natural uranium is around

A. 0.71
B. 99.29
C. 0.015
D. 29.71

View Answer

Question 76

The atomic number of a radioactive element is not changed, when it emits __________ rays.

A. α
B. β
C. γ
D. α & β

View Answer

Question 77

Atoms with same number of neutrons, but different number of nucleons are called

A. Isotones
B. Isobars
C. Isotopes
D. Isoters

View Answer

Question 78

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)

View Answer

Question 79

Which of the following radiations is the least penetrating?

A. α-rays
B. β-rays
C. γ-rays
D. X-rays

View Answer

Question 80

An element having large number of __________ is most easily subjected to nuclear fission.

A. Protons
B. Electrons
C. Neutrons
D. Nucleons

View Answer

Question 81

Main source of __________ is monazite sand.

A. Uranium
B. Polonium
C. Hafnium
D. Thorium

View Answer

Question 82

Emission of β-particles during radioactive decay of a substance is from

A. Innermost shell
B. Nucleus
C. Outermost shell
D. None of these

View Answer

Question 83

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

View Answer

Question 84

Nuclear power plant is not located at

A. Talcher (Orissa)
B. Rawatbhata (Rajasthan)
C. Kalpakkam (Tamilnadu)
D. Kaiga (Karnataka)

View Answer

Question 85

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

View Answer

Question 86

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

View Answer

Question 87

Out of the following places, heavy water plant is not located at

A. Baroda
B. Ramagundam
C. Talcher
D. Tuticorin

View Answer

Question 88

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

View Answer

Question 89

The molecular weight of heavy water is

A. 10
B. 18
C. 20
D. 36

View Answer

Question 90

Fuel for a nuclear reactor (thermal) is

A. Uranium
B. Plutonium
C. Radium
D. None of these

View Answer

Question 91

Extraction of uranium from its ore is done by __________ method.

A. Chemical
B. Pyrometallurgical
C. Physical beneficiation
D. Electrometallurgical

View Answer

Question 92

Extraction of uranium from its ore is done using __________ methods.

A. Electrometallurgical
B. Pyrometallurgical
C. Chemical
D. Physical beneficiation

View Answer

Question 93

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.

View Answer

Question 94

The half life period of a radioactive element depends on its

A. Temperature
B. Pressure
C. Amount
D. None of these

View Answer

Question 95

One 'amu' is equivalent to

A. 9.31 MeV
B. 931 eV
C. 931 Mev
D. 931J

View Answer

Question 96

The 92U238 emits an a-particle. The product is

A. 90U234
B. 90U238
C. 90U236
D. 92U236

View Answer

Question 97

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

View Answer

Question 98

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

View Answer

Question 99

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

View Answer

Question 100

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

View Answer

Question 101

Hydrogen has __________ isotopes.

A. no
B. one
C. two
D. three

View Answer

Question 102

Which of the following is not used as a moderator in nuclear reactor?

A. Molten sodium
B. Light water
C. Beryllium
D. Boron hydride

View Answer

Question 103

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

View Answer

Question 104

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

View Answer

Question 105

Hydrogen bomb employs the nuclear fusion of

A. hydrogen
B. deuterium
C. tritium
D. helium

View Answer

Question 106

__________ moderator is used in a fast breeder reactor.

A. Graphite
B. Heavy water
C. Beryllium
D. No

View Answer

Question 107

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

View Answer

Question 108

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

View Answer

Question 109

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

View Answer

Question 110

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

View Answer

Question 111

Radioactivity of an isotope is expressed in

A. Barn
B. MeV
C. Curie
D. Ergs

View Answer

Question 112

Which of the following is a non-fissile material?

A. Plutonium⁻²39
B. Uranium⁻²35
C. Uranium⁻²33
D. Thorium⁻²32

View Answer

Question 113

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

View Answer

Question 114

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

View Answer

Question 115

Which is the most commonly used molten metal for cooling of nuclear reactors ?

A. Calcium
B. Sodium
C. Mercury
D. Zinc

View Answer

Question 116

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

View Answer

Question 117

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

View Answer

Question 118

Atoms of U-238 and U-235 differ in structure by three

A. Electrons and three protons
B. Protons
C. Neutrons
D. Electrons

View Answer

Question 119

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

View Answer

Question 120

A radioactive substance does not emit

A. Α-ray
B. Proton
C. Position
D. Β-ray

View Answer

Question 121

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

View Answer

Question 122

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

View Answer

Question 123

Which of the following may not need a moderator ?

A. Candu reactor
B. Fast breeder reactor
C. Homogeneous reactor
D. Pressurised water reactor

View Answer

Question 124

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

View Answer

Question 125

Nucleus of 92U235 contains __________ protons.

A. 92
B. 235
C. 143
D. 325

View Answer

Question 126

"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.

View Answer

Question 127

The decay product of tritium (a beta emitter) is

A. lithium
B. helium
C. deuterium
D. hydrogen

View Answer

Question 128

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

View Answer

Question 129

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

View Answer

Question 130

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

View Answer

Question 131

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.

View Answer

Question 132

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

View Answer

Question 133

The most abundant isotope of natural uranium is

A. 92U238
B. 92U235
C. 92U234
D. None of these

View Answer

Question 134

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

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Question 135

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

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Question 136

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

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Question 137

Net efficiency of ordinary light water cooled nuclear reactor is about __________ percent.

A. 32
B. 52
C. 72
D. 88

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Question 138

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

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Question 139

Mass of a positron is same as that of a/an

A. Electron
B. α-particle
C. Proton
D. Neutron

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Question 140

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

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Question 141

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

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Question 142

Spent fuel from the nuclear thermal reactor contains

A. Fission products
B. Plutonium
C. Unused fuel
D. All of the above

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Question 143

Which of the following is not a naturally occurring nuclear fuel ?

A. Uranium-238
B. Thorium-233
C. Plutonium-239
D. None of these

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Question 144

Nuclear fuel usually used in a Boiling Water Reactor (BWR) is

A. Plutonium
B. Enriched uranium
C. Natural uranium
D. Thorium

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Question 145

Which is used as a coolant in nuclear reactor due to its high capture cross-section ?

A. H2
B. N2
C. He
D. CO2

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Question 146

Energy equivlant to one atomic mass unit (amu) is __________ MeV.

A. 9.31
B. 93.1
C. 931
D. 9310

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Question 147

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

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Question 148

Which is the most commonly used molten metal for cooling of nuclear reactors?

A. Calcium
B. Sodium
C. Mercury
D. Zinc

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Question 149

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

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Question 150

Percentage of the heavy water in ordi water is around

A. 0.015
B. 7.54
C. 0.71
D. 32.97

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Question 151

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

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Question 152

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

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Question 153

Which of the following is not a good moderating material?

A. Concrete
B. Boron
C. 18/8 stainless steel
D. All of the above

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Question 154

MeV is the unit of

A. radioactivity
B. energy
C. potential difference
D. none of these

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Question 155

The decrease in the atomic number is not observed in case of

A. electron capture
B. β-emission
C. α-emission
D. positron emission

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Question 156

A moderator __________ the neutrons.

A. Slows down
B. Absorbs
C. Accelerates
D. Reflects

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Question 157

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

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Question 158

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

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Question 159

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

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Question 160

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

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Question 161

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

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Question 162

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

View Answer

Question 163

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

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Question 164

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

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Question 165

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

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Question 166

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

View Answer

Question 167

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

View Answer

Question 168

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

View Answer

Question 169

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

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Question 170

A pressurised water reactor (PWR) uses pressurised water as a

A. Coolant
B. Working fluid in power turbine
C. Moderator
D. None of these

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Question 171

Uranium ore is currently mined & concentrated at

A. Jadugoda
B. Ghatsila
C. Khetri
D. Alwaye

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Question 172

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

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Question 173

Neutrons have mass approximately equal to that of __________ atoms.

A. Hydrogen
B. Helium
C. Deuterium
D. None of these

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Question 174

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

View Answer

Question 175

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

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Question 176

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

View Answer

Question 177

The second underground nuclear test was conducted by India at

A. Jaisalmer
B. Pokhran
C. Kalpakkan
D. Narora

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Question 178

The largest stable nucleus is

A. U-235
B. U-238
C. Pb-206
D. Bi-209

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Question 179

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

View Answer

Question 180

Which of the following nuclear materials is fissile?

A. Uranium⁻²38
B. Thorium⁻²32
C. Plutonium⁻²39
D. None of these

View Answer

Question 181

Out of the followingplaces, a nuclear power plant is not located at

A. Talcher (Orissa)
B. Kaiga (Karnataka)
C. Rawatbhata (Rajsthan)
D. Kalpakkam (Tamilnadu)

View Answer

Question 182

In a nuclear explosion, the energy is released primarily in the form of __________ energy-

A. potential
B. thermal
C. kinetic
D. electrical

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Question 183

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

View Answer

Question 184

The half life period of a radioactive element depends upon the

A. Temperature
B. Pressure
C. Amount of element present
D. None of these

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Question 185

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

View Answer

Question 186

Which one is the radioactive isotope of hydrogen?

A. Deuterium
B. Ortho-hydrogen
C. Tritium
D. None of these

View Answer

Question 187

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

View Answer

Question 188

Function of control rod in a nuclear reactor is to control

A. Temperature
B. Pressure
C. Fuel consumption
D. Absorption of neutrons

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Question 189

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

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Question 190

Fuel for a fast breeder reactor is

A. Plutonium
B. Uranium
C. Radium
D. Neptunium

View Answer

Question 191

The phenomenon of nuclear fission is opposite to that of

A. Radioactive decay
B. Thermionic emission
C. Nuclear fusion
D. Combustion

View Answer

Question 192

The ratio of volume of an atom to that of its nucleus is

A. 10¹²
B. 10⁻¹²
C. 10⁻⁸
D. 10⁸

View Answer

Question 193

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

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Question 194

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

View Answer

Question 195

An electron has a mass that is approximately __________ that of the proton.

A. 1836 (approximately)
B. 1/1836 (approximately)
C. 1
D. ∞

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Question 196

Final product of uranium extraction plant at Jadugoda (Bihar) is

A. uranium
B. uranium oxide
C. uranium carbide
D. magnesium diuranate

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Question 197

Isotopes of an element have different

A. Mass number
B. Electronic configuration
C. Nuclear charge
D. Chemical properties

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Question 198

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

View Answer

Question 199

Isotopes of an element have the same

A. Number of neutrons
B. Mass number
C. Electronic configuration
D. Atomic weight

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Question 200

In nuclear reactions, __________ number is conserved.

A. Mass
B. Atomic
C. Both A & B
D. Neither A nor B

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Question 201

The ratio of volume of an atom to that of its nucleus is

A. 1012
B. 10-Dec
C. 10-Aug
D. 108

View Answer

Question 202

Which of the following undergoes fission reaction easily?

A. U-235
B. U-238
C. Th-232
D. None of these

View Answer

Question 203

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

View Answer

Question 204

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?

View Answer

Question 205

The phenomenon of radioactivity was discovered by

A. Madam Curie
B. Bacquerrel
C. Roentgen
D. J.J. Thomson

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Question 206

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

View Answer

Question 207

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

View Answer

Question 208

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

View Answer

Question 209

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

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Question 210

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

View Answer

Question 211

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

View Answer

Question 212

Nuclides having the same atomic numbers are termed as

A. Isotopes
B. Isomers
C. Isotones
D. Isobars

View Answer

Question 213

Thorium⁻²32 is converted into uranium⁻²33 in a/an __________ nuclear reactor.

A. Thermal
B. Fast breeder
C. Heavy water moderated
D. Enriched uranium

View Answer

Question 214

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

View Answer

Question 215

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

View Answer

Question 216

Which is used as a coolant in nuclear reactor due to its high capture cross-section?

A. H₂
B. N₂
C. He
D. CO₂

View Answer

Question 217

Which of the following is not, a fertile material?

A. Th-232
B. U-238
C. U-233
D. None of these

View Answer

Question 218

Fast breeder Test Reactor (FBTR) is located at

A. Kalpakkam (near Madras).
B. Kota (in Rajasthan).
C. BARC (Trombay).
D. Tarapur (in Maharashtra).

View Answer

Question 219

Graphite is used in nuclear reactor as

A. Insulation lining of the reactor
B. Fuel
C. Lubricant
D. Retarder of neutron velocity

View Answer

Question 220

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

View Answer

Question 221

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

View Answer

Question 222

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.

View Answer

Question 223

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

View Answer

Question 224

In the nuclear reaction, 93N239 → 93Pu239 + ?; the missing particle is a/an

A. Electron
B. Proton
C. Neutron
D. Position

View Answer

Question 225

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

View Answer

Question 226

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

View Answer

Question 227

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.

View Answer

Question 228

__________ 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

View Answer

Question 229

Which one is radioactive in nature?

A. Helium
B. Deuterium
C. Heavy hydrogen
D. Tritium

View Answer

Question 230

The radioisotope used to study the thyroid gland is

A. Iodine
B. Cobalt
C. Iron
D. Carbon

View Answer

Question 231

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

View Answer

Question 232

Heavy water (D₂O) in a nuclear reactor serves as a

A. Coolant
B. Moderator
C. Both A & B
D. Neutron absorber

View Answer

Question 233

__________ have the same mass number, but different nuclear charge.

A. Isotopes
B. Isobars
C. Isotones
D. None of these

View Answer

Question 234

Heavy water has maximum density at __________ °C.

A. 4
B. 11.6
C. 0
D. 18.6

View Answer

Question 235

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

View Answer

Question 236

Spent fuel from the nuclear thermal reactor contains

A. fission products
B. plutonium
C. unused fuel
D. all (a), (b) & (c)

View Answer