Recently Asked Nuclear Engineering Objective Questions In Competitive’s
Q – 1 Neutrons have mass approximately equal to that of __________ atoms.
A. hydrogen
B. helium
C. deuterium
D. none of these
Ans- Option A
Q – 2 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.
Ans- Option D
Q – 3 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.
Ans- Option B
Q – 4 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.
Ans- Option B
Q – 5 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
Ans- Option B
Q – 6 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.
Ans- Option A
Q – 7 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.
Ans- Option B
Q – 8 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.
Ans- Option C
Q – 9 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
Ans- Option C
Q – 10 Coolant used in a fast breeder reactor is
A. molten sodium
B. heavy water
C. ordinary water
D. helium
Ans- Option A
Q – 11 An element having large number of __________ is most easily subjected to nuclear fission.
A. protons
B. electrons
C. neutrons
D. nucleons
Ans- Option D
Q – 12 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 (a), (b) and (c).
Ans- Option D
Q – 13 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
Ans- Option B
Q – 14 The number of neutrons in the nucleus of Uranium-233 (92U233) is
A. 141
B. 92
C. 233
D. 325
Ans- Option A
Q – 15 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
Ans- Option A
Q – 16 Nuclear power reactor located at Tarapur is of __________ type.
A. fast breeder
B. pressurised water
C. boiling water
D. gas cooled
Ans- Option C
Q – 17 Which of the following is not an ore of uranium?
A. Pitchblende
B. Kyanite
C. Carnotite
D. Rescolite
Ans- Option B
Q – 18 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.
Ans- Option A
Q – 19 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.
Ans- Option D
Q – 20 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
Ans- Option A
Q – 21 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.
Ans- Option A
Q – 22 Which of the following is a non-fissile material?
A. Plutonium-239
B. Uranium-235
C. Uranium-233
D. Thorium-232
Ans- Option D
Q – 23 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
Ans- Option A
Q – 24 Percentage of natural uranium present in uranium ore found in Jadugoda (Jharkhand) is
A. 0.1
B. 1
C. 3
D. 12
Ans- Option A
Q – 25 Nucleus of tritium has __________ neutrons.
A. 1
B. 2
C. 3
D. 5
Ans- Option B
Q – 26 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 (a), (b) and (c).
Ans- Option A
Q – 27 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
Ans- Option C
Q – 28 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 (a), (b) and (c).
Ans- Option D
Q – 29 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.
Ans- Option B
Q – 30 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
Ans- Option D
Q – 31 First experimental observation of nuclear fission was done by
A. Plane
B. Rutherford
C. Fermi
D. Hahn and Strassman
Ans- Option C
Q – 32 Coolant present in the primary circuit of a pressurised water reactor is high pressure
A. sub cooled water
B. saturated water
C. superheated steam
D. saturated steam
Ans- Option B
Q – 33 Extraction of uranium from its ore is done using __________ methods.
A. electrometallurgical
B. pyrometallurgical
C. chemical
D. physical beneficiation
Ans- Option C
Q – 34 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.
Ans- Option A
Q – 35 ‘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.
Ans- Option A
Q – 36 Fast breeder reactors are most usable in India, because of our largest __________ deposits.
A. thorium
B. plutonium
C. uranium
D. none of these
Ans- Option A
Q – 37 The main ore of thorium is
A. pitchblende
B. monazite sand
C. limonite
D. galena
Ans- Option B
Q – 38 Critical energy should be __________ the neutron binding energy of the atom in order to initiate a nuclear fission.
A. equal to
B. less than
C. more than
D. either more or less==
Ans- Option C
Q – 39 In nuclear reactions, __________ number is conserved.
A. mass
B. atomic
C. both (a) & (b)
D. neither (a) nor (b)
Ans- Option C
Q – 40 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
Ans- Option A
Q – 41 Function of control rod in a nuclear reactor is to control
A. temperature
B. pressure
C. fuel consumption
D. absorption of neutrons
Ans- Option D
Q – 42 The main ore of uranium is
A. pitchblende
B. monazite sand
C. cassiterite
D. chalcopyrite
Ans- Option A
Q – 43 Which of the following nuclear materials is fissile?
A. Uranium-238
B. Thorium-232
C. Plutonium-239
D. None of these
Ans- Option C
Q – 44 Solar energy results from __________ reaction.
A. fission
B. combustion
C. thermonuclear
D. none of these
Ans- Option C
Q – 45 Heavy water (D2O) in a nuclear reactor serves as a
A. coolant
B. moderator
C. both (a) & (b)
D. neutron absorber
Ans- Option C
Q – 46 Atoms of U-238 and U-235 differ in structure by three
A. electrons and three protons
B. protons
C. neutrons
D. electrons
Ans- Option C
Q – 47 A radioactive isotope undergoes decay with respect to time following __________ law.
A. logarithmic
B. exponential
C. linear
D. inverse square
Ans- Option B
Q – 48 Main source of __________ is monazite sand.
A. uranium
B. polonium
C. hafnium
D. thorium
Ans- Option D
Q – 49 The first underground nuclear test was conducted by India at
A. Jaisalmer
B. Pokharan
C. Kalpakkam
D. Narora
Ans- Option B
Q – 50 Which of the following is not a good moderating material?
A. Concrete
B. Boron
C. 18/8 stainless steel
D. All (a), (b) and (c)
Ans- Option D
Q – 51 The molecular weight of heavy water is
A. 10
B. 18
C. 20
D. 36
Ans- Option C
Q – 52 The size of an atom is of the order of one
A. Angstrom
B. fermi
C. micron
D. mm
Ans- Option A
Q – 53 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.
Ans- Option D
Q – 54 The phenomenon of nuclear fission is opposite to that of
A. radioactive decay
B. thermionic emission
C. nuclear fusion
D. combustion
Ans- Option C
Q – 55 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.
Ans- Option A
Q – 56 Coolant used in a boiling water reactor is
A. hydrogen gas
B. water
C. steam
D. a mixture of water & steam
Ans- Option D
Q – 57 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
Ans- Option C
Q – 58 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.
Ans- Option C
Q – 59 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
Ans- Option A
Q – 60 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
Ans- Option D
Q – 61 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
Ans- Option C
Q – 62 The phenomenon of radioactivity was discovered by
A. Madam Curie
B. Bacquerrel
C. Roentgen
D. J.J. Thomson
Ans- Option B
Q – 63 Out of the following places, heavy water plant is not located at
A. Baroda
B. Ramagundam
C. Talcher
D. Tuticorin
Ans- Option B
Q – 64 A pressurised water reactor (PWR) uses pressurised water as a
A. coolant.
B. working fluid in power turbine.
C. moderator.
D. none of these.
Ans- Option A
Q – 65 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.
Ans- Option A
Q – 66 Which of the following is the best nuclear fuel?
A. Np- 239
B. U-234
C. Pu-239
D. Th-236
Ans- Option C
Q – 67 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.
Ans- Option B
Q – 68 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.
Ans- Option C
Q – 69 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
Ans- Option A
Q – 70 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.
Ans- Option C
Q – 71 Nuclear power plant is not located at
A. Talcher (Orissa)
B. Rawatbhata (Rajasthan)
C. Kalpakkam (Tamilnadu)
D. Kaiga (Karnataka)
Ans- Option A
Q – 72 Isotopes of an element have the same
A. number of neutrons
B. mass number
C. electronic configuration
D. atomic weight
Ans- Option C
Q – 73 Extraction of uranium from its ore is done by __________ method.
A. chemical
B. pyrometallurgical
C. physical beneficiation
D. electrometallurgical
Ans- Option A
Q – 74 Radioactivity of an isotope is expressed in
A. barn
B. MeV
C. Curie
D. Ergs=
Ans- Option C
Q – 75 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.
Ans- Option C
Q – 76 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.
Ans- Option D
Q – 77 Net efficiency of ordinary light water cooled nuclear reactor is about __________ percent.
A. 32
B. 52
C. 72
D. 88
Ans- Option A
Q – 78 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
Ans- Option A
Q – 79 The new nucleus formed after β-decay of a radioactive element has
A. less atomic number
B. less atomic weight
C. more atomic number
D. more atomic weight
Ans- Option A
Q – 80 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
Ans- Option D
Q – 81 ‘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.
Ans- Option B
Q – 82 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)
Ans- Option B
Q – 83 __________ 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
Ans- Option A
Q – 84 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.
Ans- Option B
Q – 85 Quantity of fissionable material (i.e. U-235) in natural uranium is __________ percent.
A. 0.71
B. 6.31
C. 99.29
D. 12.73
Ans- Option A
Q – 86 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
Ans- Option B
Q – 87 Which of the following isotopes is not present in natural uranium?
A. U-238
B. U-234
C. U-235
D. U-232
Ans- Option D
Q – 88 Which of the following is not used as a moderator in nuclear reactor?
A. Molten sodium
B. Light water
C. Beryllium
D. Boron hydride
Ans- Option A
Q – 89 Percentage of the heavy water in ordi water is around
A. 0.015
B. 7.54
C. 0.71
D. 32.97
Ans- Option A
Q – 90 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 (a), (b) and (c).
Ans- Option D
Q – 91 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.
Ans- Option C
Q – 92 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.
Ans- Option A
Q – 93 Energy produced in the nuclear fission is of the order of __________ MeV.
A. 20
B. 200
C. 1000
D. 2000
Ans- Option B
Q – 94 In β-decay of radioactive material, the ratio of neutron to proton
A. increases.
B. remains same.
C. decreases.
D. is unpredictable; may increase or decrease.
Ans- Option C
Q – 95 Nuclear fuel usually used in a Boiling Water Reactor (BWR) is
A. plutonium
B. enriched uranium
C. natural uranium
D. thorium
Ans- Option B
Q – 96 Which is not a fissile nuclear material?
A. U-233
B. U-235
C. U-238
D. Pu-239
Ans- Option C
Q – 97 Heavy water plant is not located at
A. Talcher
B. Tuticorin
C. Ramagundam
D. Kota
Ans- Option C
Q – 98 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
Ans- Option A
Q – 99 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.
Ans- Option C
Q – 100 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
Ans- Option C