The energy required to be applied to a radioactive nucleus for the emission of a neutron is
1 MeV
2.4 MeV
4.3 MeV
7.8 MeV
Correct Answer :
D. 7.8 MeV
Related Questions
U235 will undergo fission by
High energy (fast) neutrons alone
Low energy (slow) neutrons alone
Either fast or slow neutrons
Medium energy neutrons
Plutonium is produced
As basic raw material
By neutron irradiation of Uz
By neutron irradiation of thorium
Artificially
Which of the following nuclear reactor does not need a heat exchanger for generation of steam?
Gas cooled
Liquid metal cooled
Pressurised water
Boiling water
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
The risk of radioactive hazard is greatest in the turbine with following reactor
Pressurised water
Boiling water
Gas cooled
Liquid metal cooled
A fast breeder reactor uses
90% U₂₃₅
U₂₃₈
U₂₃₅
Pu₂₃₉
Pressurised water reactor is designed
For boiling pi water in the core
To use liquid sodium metal as coolant
To use intermediate coolant
To prevent the water coolant from boiling in the core
In natural uranium, the constituents of three naturally occuring isotopes are
U₂₃₄ = 0.006%, U₂₃₅ = 0.712% and U₂₃₈ = 99.282%
U₂₃₄ = 0.712%, U₂₃₅ = 0.006% and U₂₃₈ = 99.282%
U₂₃₄ = 99.282%, U₂₃₅ = 0.006% and U₂₃₈ = 0.712%
U₂₃₄ = 0.006%, U₂₃₅ = 99.282% and U₂₃₈ = 0.712%
In a fission process, maximum percentage of energy is released as
Kinetic energy of neutrons
Kinetic energy of fission products
Instantaneous release of gamma rays
Gradual radioactive decay of fission products
Amongst the following, the fissionable materials are
U₂₃₃ and Pu₂₂₉
U₂₃₁ and Pu₂₃₃
U₂₃₅ and Pu₂₃₅
U₂₃₈ and Pu₂₃₉
A pressurised water reactor employs pressurises for the following application
To maintain constant pressure in primary circuit under varying load
To Supply high pressure steam
To increase pressure of water in primary circuit
To provide sub cooled water at high pressure
A nuclear fission is initiated when the critical energy as compared to neutron binding energy of the atoms is
Same
More
Less
There is no such criterion
The function of control rods in nuclear plants is to
Control temperature
Control radioactive pollution
Control absorption of neutron
Control fuel consumption
The efficiency of a nuclear power plant in comparison to a conventional thermal power plant is
Same
More
Less
May be less or mote depending on size
The most commonly used moderator in nuclear plants is
Heavy water
Concrete and bricks
Graphite and concrete
Graphite
Which of the following are ferrite materials?
U₂₃₃ and Pu₂₃₉
U
U₂₃₈ and Pu₂₃₉
U₂₃₈ and Th₂₃₉
The commonly used material for shielding is
Lead or concrete
Lead and tin
Graphite or cadmium
Thick galvanised sheets
Effective moderators are those materials which contain
Light weight atoms
Heavy weight atoms
Critical atoms
Zero weight atoms
The material most commonly used for shielding is
Carbon
Lead
Concrete
All of these
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
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
Each fission of U₂₃₅ produces on the average _________ fast neutrons as a product of reaction.
2.46
24.6
246
2460
Breeder reactor has a conversion ratio of
Unity
More than unity
Less than unity
Zero
A moderator, in nuclear power plants, is a medium introduced into the fuel mass in order to
Slow down the speed of fast moving neutrons
Control the reaction
Reduce the temperature
Extracts heat from nuclear reaction
Boiling water reactor employs
Boiler
Direct cycle of coolant system
Double circuit system of coolant cycle
Multi passes system
Ferrite material is
The most fissionable material
The basic fuel for nuclear paints
Basic raw material for nuclear plants
The material which absorbs neutrons and undergoes spontaneous changes leading to the formation of fissionable material
Which of the following is more appropriate for a moderator? One which
Does not absorb neutrons
Absorbs neutrons
Accelerates neutrons
Eats up neutrons
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.
Uranium has isotopes
U₂₃₄
U₂₃₅
U₂₃₈
All of these
In order to have constant chain reaction to produce a constant rate of heat output, the value of ratio of the number of neutrons in one generation to the number of neutrons in the immediately preceding generation must be
Greater than 1.0
Less than 1.0
Equal to zero
Equal to 1.0