Natural uranium is made up of
99.282% U₂₃₈, 0.712% U₂₃₅, 0.006% U₂₃₄
99.282% U₂₃₅, 0.712% U₂₃₈, 0.06%' U₂₃₄
99.282% U₂₃₄, 0.712% U₂₃₈, 0.006% U₂₃₅
99.282% U₂₃₅, 0.712% U₂₃₄, 0.006% U₂₃₈
Correct Answer :
A. 99.282% U₂₃₈, 0.712% U₂₃₅, 0.006% U₂₃₄
Related Questions
The material most commonly used for shielding is
Carbon
Lead
Concrete
All of these
U238 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
Which of the following statement is correct regarding the features of a Breeder reactor?
It produces more fuel than it consumes.
It requires highly enriched fuel.
It requires liquid sodium metal as moderator.
All of the above
A fission chain reaction in uranium can be developed
By increasing the contents of U₂₃₅
By slowing down fast neutrons so that U₂₃₅ fission continues by slow neutron
Both (A) and (B)
None of these
Atomic number of an element in the periodic table represents the numbers of
Protons in the nucleus
Electrons in the nucleus
Neutrons in the nucleus
Electrons in the atom
The process by which a heavy nucleus is spitted into two light nuclei is known as
Splitting
Fission
Fusion
Disintegration
A moderator generally used in nuclear power plants is
Graphite
Heavy water
Concrete
Graphite and concrete
Ideally the neutron flux in reactor should be
Maximum in centre and zero at side
Maximum at side and zero in canter
Uniform throughout
Zero throughout
The coolant used in boiling water reactor is
CO2
Pressurised water
Mixture of water and steam
Liquid metal
The presence of reflector in nuclear power plants results in
Increased production of neutrons
Complete absorption of neutrons
Controlled production of neutrons
Decreased leakage of neutrons
Plutonium is produced
As basic raw material
By neutron irradiation of Uz
By neutron irradiation of thorium
Artificially
Half life of a radioactive isotope corresponds to the time required for half of the following to decay
Electrons
Protons
Neutrons
Atom
A power plant giving least running cost of production of electrical power is
Steam power plant
Gas turbine power plant
Hydro electric power plant
Nuclear power plant
Enriched uranium is required as a fuel in a nuclear reactor, if light water is used as moderator and coolant, because light water has
High neutron absorption cross-section
Low moderating efficiency
High neutron scatter cross-section
Low neutron absorption cross-section
Boiling water reactor uses the following as moderator, coolant and working fluid
Ordinary fluid
Heavy water
Molten lead
Hydrogen gas
Reflector in nuclear power plants _________ neutron leakage.
Increases
Decreases
Have no effect on
None of these
Reflector in nuclear plants is used to
Return the neutrons back into the core
Shield the radioactivity completely
Check pollution
Conserve energy
When a reactor becomes critical, then the production of neutrons is
Infinite
Zero
Exactly balanced by the loss of neutrons through leakage
Initiated
Pick up the wrong statement
In a heterogeneous or solid fuel reactor, the fuel is mixed in a regular pattern within moderator.
Slow or thermal neutrons have energy of the order or 0.025 eV
Fast neutrons have energies above 1000 eV
Fast reactor uses moderator
Enriched uranium is one in which
Percentage of U₂₃₅ has been artificially increased
Percentage of U has been artificially increased
Percentage of U₂₃₄ has been artificially increased
Extra energy is pumped from outside
Boiling water reactor employs
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is
Heavy water
Graphite
Carbon dioxide
No moderator is needed
Plutonium (Pu239) is produced
Artificially
When U238 is irradiated by neutrons
By fission of Th232
As basic raw material
Nuclear reactors are used
To produce heat for thermoelectric power
To produce fissionable material
To propel ships, submarines, aircrafts
All of these
The fuel needed, with reflector in nuclear power plant, in order to generate sufficient neutrons to sustain a chain reaction, would be
More
Less
Same
Zero
Superheated steam is generated in following reactor
Boiling water
Gas cooled
Pressurised water
All of the above
Reactors for propulsion applications use
Natural uranium
Molten lead
Any form of uranium
Thorium
Breeder reactor has a conversion ratio of
Unity
More than unity
Less than unity
Zero
In fast breeder reactors
Any type of moderator can be used
Graphite is used as the moderator
Heavy water is used as the moderator
Moderator is dispensed with.
In triggering fission, which types of neutrons are more effective?
Fast
Slow
In bulk
Static