Q.1

Nucleus of tritium has __________ neutrons.

  • 1
  • 2
  • 3
  • 5
Q.2

Which of the following is the most harmful for the human being ?

  • β-rays
  • X-rays
  • γ-rays
  • ultra violet rays
Q.3

Candu reactor is a __________ nuclcear reactor.

  • natural uranium fuelled heavy water cooled & moderated
  • highly enriched uranium (85% U-235) fuelled
  • homogeneous
  • fast breeder
Q.4

"Critical mass" is the minimum mass of nuclear fissile material required for the

  • sustainment of chain reaction.
  • power generation on commercial scale.
  • economic power generation.
  • none of these.
Q.5

Which of the following gases has very high neutron capture cross-section, making it unsuitable as a coolant in nuclear reactor?

  • N2
  • He
  • CO2
  • H2
Q.6

Unit of radioactivity is

  • barn
  • fermi
  • angstrom
  • curie
Q.7

Molten sodium is used as a coolant in a fast breeder reactor, because of its

  • excellent moderating properties.
  • neutron breeding capability.
  • faster heat removal capability from the core.
  • capability to increase the reaction rate in the core.
Q.8

Which of the following nuclear materials is fissile ?

  • Uranium-238
  • Thorium-232
  • Plutonium-239
  • None of these
Q.9

The first underground nuclear test was conducted by India at

  • Jaisalmer
  • Pokharan
  • Kalpakkam
  • Narora
Q.10

When the difference between mass number and atomic number of atoms of two or more elements are same, the atoms are termed as

  • isomers
  • isotopes
  • isobars
  • isotones
Q.11

Fuel for a fast breeder reactor is

  • plutonium
  • uranium
  • radium
  • neptunium
Q.12

Enriched uranium means that, it contains

  • more than 0.71% of U-235.
  • only fertile material.
  • only fissile material.
  • no impurities.
Q.13

Nuclear power reactor located at Tarapur is of __________ type.

  • fast breeder
  • pressurised water
  • boiling water
  • gas cooled
Q.14

Which of the following is not an ore of uranium ?

  • Pitchblende
  • Kyanite
  • Carnotite
  • Rescolite
Q.15

Percentage of natural uranium present in uranium ore found in Jadugoda (Jharkhand) is

  • 0.1
  • 1
  • 3
  • 12
Q.16

Heavy water is preferred over ordinary water as a coolant, because it.

  • acts both as an efficient coolant as well as a moderator.
  • can be heated to a higher temperature without pressurizing.
  • is less prone to radiation damage.
  • all (a), (b) and (c).
Q.17

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

  • protons
  • electrons
  • neutrons
  • nucleons
Q.18

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

  • innermost shell
  • nucleus
  • outermost shell
  • none of these
Q.19

Radioactive decay is a __________ change.

  • chemical
  • nuclear
  • physical
  • none of these
Q.20

Which of the following is a non-fissile material ?

  • Plutonium-239
  • Uranium-235
  • Uranium-233
  • Thorium-232
Q.21

The velocity of thermal (slow) neutrons triggering nuclear fission reaction (having energy equal to 0.eV) is about __________ metres/second.

  • 1100
  • 2200
  • 3300
  • 4400
Q.22

Critical energy should be __________ the neutron binding energy of the atom in order to initiate a nuclear fission.

  • equal to
  • less than
  • more than
  • either more or less
Q.23

The number of neutrons in the nucleus of Uranium-(92U233) is

  • 141
  • 92
  • 233
  • 325
Q.24

Coolant present in the primary circuit of a pressurised water reactor is high pressure

  • sub cooled water
  • saturated water
  • superheated steam
  • saturated steam
Q.25

Critical energy should be __________ the neutron binding energy of the atom in order to initiate a nuclear fission.

  • equal to
  • less than
  • more than
  • either more or less
Q.26

Neutrons have mass approximately equal to that of __________ atoms.

  • hydrogen
  • helium
  • deuterium
  • none of these
Q.27

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

  • electrometallurgical
  • pyrometallurgical
  • chemical
  • physical beneficiation
Q.28

Main source of __________ is monazite sand.

  • uranium
  • polonium
  • hafnium
  • thorium
Q.29

The critical mass of a fissionable material can be reduced by

  • heating it.
  • cooling it.
  • surrounding it by neutron reflecting material.
  • surrounding it by neutron absorbing material.
Q.30

Fast breeder test reactor at Kalpakkam is designed for using

  • thorium as a fertile material.
  • U-238 as a fertile material.
  • helium as a coolant.
  • uranium ore directly as a fuel.
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