Description : Which of the following can be used to absorb neutrons to control the chain reaction during nuclear fission? (1) Boron (2) Heavy water (3) Uranium (4) Plutonium
Last Answer : (1) Boron Explanation: Boron shielding is used as a control for nuclear reactors, taking advantage of its high cross-section for neutron capture. Elemental boron is rare and ... aluminium. Crystalline boron is chemicallyinert and resistant to attack by boiling hydrofluoric or hydrochloric acid.
Description : wo elements which are used to absorb neutrons to control the chain reaction during nuclear fission are - (1) Boron and Cadmium (2) Boron and Plutonium (3) Cadmium and Uranium (4) Uranium and Boron
Last Answer : (1) Boron and Cadmium Explanation: Since the continued chain reaction of a nuclear fission reactor depends upon at least one neutron from each fission being absorbed by another fissionable nucleus, the ... and then the control rods are slowly lifted until a chain reaction can just be sustained.
Description : 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
Last Answer : (A) Slow down the secondary neutrons
Description : 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) ... radiation (C) Conversion of fissile material into fertile material (D) Velocity of the secondary neutrons
Last Answer : (A) Chain reaction and hence the power output by regulating the number of secondary neutrons causing fission
Description : The two elements which are used to absorb the neutrons in nuclear fission during chain reaction
Last Answer : Boran and Cadmium
Description : Of the following, which non-fissioning element is used in the cooling water of nuclear power plants to help control the rate of the fission reaction by absorbing neutrons: w) zirconium x) boron y) krypton z) cesium
Last Answer : ANSWER: X -- BORON
Description : Which of the following can be used to absorb neutrons to control the chain reaction during nuclear fission ? (1) Boron (2) Heavy water (3) Uranium (4) Plutonium
Last Answer : Boron
Description : Two elements which are used to absorb neutrons to control the chain reaction during nuclear fission are (1) Boron and Cadmium (2) Boron and Plutonium (3) Cadmium and Uranium (4) Uranium and Boron
Last Answer : Boron and Cadmium
Description : Moderator is a material which is used to slow down the neutrons produced during nuclear fission. The neutrons from the source are of high speed and en
Last Answer : Moderator is a material which is used to slow down the neutrons produced during nuclear fission ... neutrons C. magnetic neutrons D. electric neutrons
Last Answer : Moderator is a material which is used to slow down the neutrons produced during nuclear fission. The ... water B. Graphite C. Beryllium D. Sodium
Last Answer : Moderator is a material which is used to slow down the neutrons produced during nuclear fission. The ... mass number only D. be all the above three
Last Answer : Moderator is a material which is used to slow down the neutrons produced during nuclear fission ... . absorbs thermal energy. Produced in the reactors
Description : In a nuclear reactor the moderator is usually made of graphite placed between the fuel rods used to slow down neutrons all of the above none of the above?
Last Answer : Feel Free to Answer
Description : Who have the highest energy gamma rays or neutrons produced from nuclear reactor?
Last Answer : Not sure
Description : Which is are used nuclear reactors to absorb neutrons?
Last Answer : control rods
Description : Choose the incorrect statement from the following: (a) The nuclear becomes weak if the nucleus contains too many protons compared to the number of neutrons (b) The nuclear force becomes weak if the ... (d) The nuclear force becomes very strong if the nucleus contains a large number of nucleons.
Last Answer : Ans:(d)
Description : The nuclear particles that are assumed to hold nucleons together are (a) Electrons (b) Positrons (c) Neutrons (d) Mesons
Description : In an atomic explosion enormous energy is released which is due to the - (1) Conversions of neutrons into protons (2) Conversion of chemical energy into nuclear energy (3) Conversion of mechanical energy into nuclear energy (4) Conversion of mass into energy
Last Answer : (4) Conversion of mass into energy
Description : The enormous amount of energy released in an explosion of an atomic bomb is due to the - (1) conversion of mass into energy (2) conversion of chemical energy into heat energy (3) conversion of mechnical energy into nuclear energy (4) conversion of neutrons into protons
Last Answer : (4) conversion of neutrons into protons Explanation: The enormous amount of energy released in an explosion of an atomic bomb is due to the converson of neutrons into protons. When, a neutron strikes ... , each of which is a nucleus with about half the protons and neutrons of the original nucleus.
Description : Graphite is used in nuclear reactors for- (1) reducing the speed of fast neutrons (2) cooling the reactor (3) absorbing neutrons (4) None of the above
Last Answer : (1) reducing the speed of fast neutrons Explanation: A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows unenriched uranium to be used as nuclear fuel.
Description : Neutrons are slowed down in a nuclear reactor by – (1) Fissionable Material (2) Moderator (3) Control rods (4) Cooling system
Last Answer : (2) Moderator Explanation: In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
Description : In a nuclear reactor the material use for absorbing neutrons is – (1) zinc (2) radium (3) lead (4) cadmium
Last Answer : (4) cadmium Explanation: One isotope of cadmium, 113Cd, absorbs neutrons with very high probability if they have an energy below the cadmium cut-off and transmits them otherwise. The cadmium ... below the cut-off are deemed slow neutrons, distinguishing them from intermediate and fast neutrons.
Description : The nuclear particles which are assumed to hold the nucleons together are - (1) positrons (2) neutrons (3) electrons (4) mesons
Last Answer : (4) mesons Explanation: The nuclear particles which are assumed to hold the nucleons together are mesons.
Description : 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
Last Answer : (C) Neutrons & gamma
Description : The velocity of thermal (slow) neutrons triggering nuclear fissionreaction (having energy equal to 0.025 eV) is about __________ metres/second. (A) 1100 (B) 2200 (C) 3300 (D) 4400
Last Answer : (B) 2200
Description : 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
Last Answer : (A) Protect the walls of the reactor from radiation damage
Description : 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
Last Answer : (D) Fission of U-235 by neutrons
Description : An element having large number of __________ is most easily subjected to nuclear fission. (A) Protons (B) Electrons (C) Neutrons (D) Nucleons
Last Answer : (D) Nucleons
Description : 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
Last Answer : (A) Uses slower neutrons for fission
Description : 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
Last Answer : (A) Kinetic energy of fission products
Description : 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
Last Answer : (B) A compound of oxygen and deuterium
Description : 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
Last Answer : (D) Be free from radiation damage and non-corrosive
Description : The number of neutrons accompanying the formationof 54Xe 139 and 38Sr 94 from the absorption of a slow neutron by 92U235 , followed by nuclear fission is (A) 1 (B) 2 (C) 3 (D) 4
Last Answer : (C) 3
Description : The speed of neutrons in a nuclear reactor is reduced with the help of
Last Answer : graphite / heavy water.
Description : The part of the nuclear reactor that controls the speed of neutrons released during nuclear fission is
Last Answer : moderator.
Description : A moderator is used in nuclear reactor in order to ? A. Accelerate the neutrons B. Slow down the speed of the neutrons (Answer) C. Increase the number of elections D. Decrease the number of electrons E. None of these
Last Answer : B. Slow down the speed of the neutrons (Answer)
Description : Biological shield in a nuclear reactor is generally provided to protect against the (A) α-rays (B) β-rays (C) Gamma rays & neutrons (D) Electrons
Last Answer : Option C
Description : Most of the new atoms formed when atoms in a nuclear reactor capture neutrons without fissioning are: w) fission products x) activation products y) actinides z) lead isotopes
Last Answer : ANSWER: Y -- ACTINIDES
Description : Reactors in commercial nuclear power plants in the U.S. are often referred to as thermal reactors. A thermal reactor uses: w) fissionable plutonium-239 as fuel. x) a relatively low heat output. y) neutrons moderated to relatively low energies. z) liquid sodium as a coolant.
Last Answer : ANSWER: Y -- NEUTRONS MODERATED TO RELATIVELY LOW ENERGIES.
Description : The neutrons in an atom: w) are part of the nuclear charge x) rotate about the nucleus in elliptical orbits y) vary in number with different isotopes z) are always equal in number to the total number of protons
Last Answer : ANSWER: Y -- VARY IN NUMBER WITH DIFFERENT ISOTOPES
Description : In the nuclear reactors, moderators are used to : (1) Accelerate neutrons (2) Absorb the neutrons (3) Slow down the neutrons (4) Generate neutrons
Last Answer : Slow down the neutrons
Description : Which one of the following takes place during a nuclear fusion? (1) a heavy nucleus bombarded by neutrons breaks up (2) a heavy nucleus breaks up spontaneously (3) two light nuclei combine to form a heavy nucleus (4) a light nucleus breaks up spontaneously
Last Answer : two light nuclei combine to form a heavy nucleus
Description : Neutrons are slowed down in a nuclear reactor by (1) Fissionable material (2) Moderator (3) Control rods (4) Cooling system
Last Answer : Moderator
Description : The enormous amount of energy released in an explosion of an atmoic bomb is due to the (1) conversion of mass into energy (2) conversion of chemical energy into heat energy (3) conversion of mechnical energy into nuclear energy (4) conversion of neutrons into protons
Last Answer : conversion of neutrons into protons
Description : In a nuclear reactor the material use for absorbing neutrons is (1) zinc (2) radium (3) lead (4) cadmium
Last Answer : cadmium
Description : In the neutron`-`induced fissioin reaction of `._(92)U^(235)` one of the products if `._(37)Rb^(95),` in this mode, another nuclide and three neutrons
Last Answer : In the neutron`-`induced fissioin reaction of `._(92)U^(235)` one of the products if `._(37)Rb^(95),` in this ... `._(55)^(145)Co` D. `._(54)^(143)Xe`
Description : 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
Last Answer : (A) Rapid heat transfer from the core
Description : A chain reaction in which the number of neutrons produced is kept constant is called
Last Answer : controlled chain reaction.
Description : Participation of __________ is involved in the occurrence of a chemical reaction. (A) Protons (B) Neutrons (C) Electrons (D) None of these
Last Answer : (C) Electrons
Description : In the fission of U235, what is the average number of neutrons produced in the fission reaction? w) 1.5 x) 2.5 y) 3.5 z) 4.5
Last Answer : ANSWER: X -- 2.5