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

1 Answer

Answer :

(A) Chain reaction and hence the power output by regulating the number of
secondary neutrons causing fission

Related questions

Description : 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)

Last Answer : (D) All (A), (B) and (C)

Description : Fast breeder reactors do not (A) Use Th-232 as fissile fuel (B) Convert fertile material to fissile material (C) Use fast neutrons for fission (D) Use molten sodium as coolant

Last Answer : (A) Use Th-232 as fissile fuel

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 : If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor. (A) Critical (B) Breeder (C) Fertile (D) Heterogeneous

Last Answer : (B) Breeder

Description : A fertile material is the one, which can be (A) Converted into fissile material on absorption of neutron (B) Fissioned by slow (thermal) neutrons (C) Fissioned by fast neutrons

Last Answer : (A) Converted into fissile material on absorption of neutron

Description : In a breeder reactor --------- a. amount of fuel decreases b. amount of fuel increases c. amount of fuelremain same d. fissile material is converted in to fertile

Last Answer : b. amount of fuel increases

Description : Critical mass" is the minimum mass of nuclear fissile material required for the (A) Sustainment of chain reaction (B) Power generation on commercial scale (C) Economic power generation (D) None of these

Last Answer : (A) Sustainment of chain reaction

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 : 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 : 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 : 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 : A homogeneous reactor is the one, in which the (A) Fissile atoms are evenly distributed throughout the mass of nuclear reactor (B) Same substance (e.g. heavy water) is used as moderator & coolant (C) The fuel and the moderator is mixed to form a homogeneous material (D) All (A), (B) and (C)

Last Answer : (C) The fuel and the moderator is mixed to form a homogeneous material

Description : Critical mass" is the minimum mass of nuclear fissile materialrequired for the (A) Sustainment of chain reaction (B) Power generation on commercial scale (C) Economic power generation (D) None of these

Last Answer : (A) Sustainment of chain reaction

Description : The two elements which are used to absorb the neutrons in nuclear fission during chain reaction

Last Answer : Boran and Cadmium

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 : A nuclear reactor harnesses nuclear energy by A. Nuclear fusion B. Spontaneous fission C. Uncontrolled chain reaction D. Controlled chain reaction

Last Answer : ANSWER: D

Description : 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

Last Answer : (C) Uranium-233

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 : The part of the nuclear reactor that controls the speed of neutrons released during nuclear fission is

Last Answer : moderator.

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 : Enriched uranium means that, it contains (A) More than 0.71% of U-235 (B) Only fertile material (C) Only fissile material (D) No impurities

Last Answer : (A) More than 0.71% of U-235

Description : __________ is not used as the control rod material in a nuclear reactor. (A) Cobalt (B) Hafnium (C) Cadmium (D) Boron

Last Answer : (A) Cobalt

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 : Thorium is mainly used (A) For the manufacture of gas mantles (B) As a fissile fuel in a nuclear reactor (C) In the manufacture of hydrogen bomb (D) In the treatment of cancer

Last Answer : (A) For the manufacture of gas mantles

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 : 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 : Neutrons are slowed down in a nuclear reactor by (1) Fissionable material (2) Moderator (3) Control rods (4) Cooling system

Last Answer : Moderator

Description : In a nuclear power reactor, fission produces heat which is used to produce electricity. A reactor producing more fissionable material than it consumes is known as what kind of reactor? 

Last Answer : ANSWER: BREEDER REACTOR 

Description : The part of a nuclear power plant that prevents thermal pollution of lakes or rivers is the: w) reactor x) coolant/moderator y) cooling tower z) control rod

Last Answer : ANSWER: Y -- COOLING TOWER

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

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. The ... water B. Graphite C. Beryllium D. Sodium

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. The ... mass number only D. be all the above three

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 ... . absorbs thermal energy. Produced in the reactors

Description : Which material is used in controlling chain reaction in a nuclear reactor?  A) Thorium B) Uranium C) Boron D)Beryllium

Last Answer : Which material is used in controlling chain reaction in a nuclear reactor?  A) Thorium B) Uranium C) Boron D)Beryllium

Description : The phenomenon of nuclear fission is opposite to that of (A) Radioactive decay (B) Thermionic emission (C) Nuclear fusion (D) Combustion

Last Answer : (C) Nuclear fusion

Description : Explain difference between fissile and fertile materials.

Last Answer : The materials which can give nuclear fission e.g. U 35, Pu 39, U 33 are fissile materi¬als. Fertile material itself is not fissionable, but it can be converted to a fissionable material by irradiation of neutrons in a nuclear reactor.

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 : 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 : What is the function of control rod in nuclear reactor?

Last Answer : These rods absorb neutrons and stop the chain reaction to proceed further.. Some control rods are made from an alloy of silver and cadmium. Some are made from boron mixed with iron or carbon. ... happens and the reactor gets colder.The control rods can used to shut the reactor down completely.

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 : In a nuclear reactor the material use for absorbing neutrons is (1) zinc (2) radium (3) lead (4) cadmium

Last Answer : cadmium

Description : Which is not a fissile nuclear material? (A) U-233 (B) U-235 (C) U-238 (D) Pu-239

Last Answer : (C) U-238

Description : Thermal nuclear reactors using enriched uranium as fuel contains a maximum of __________ percent fissile material i.e. U-235. (A) 1 (B) 2 (C) 3 (D) 7

Last Answer : (C) 3

Description : Fast breeder nuclear reactors using enriched uranium as fuel may contain upto a maximum of __________ percent of U-235 (i.e. fissile material). (A) 15 (B) 45 (C) 65 (D) 85

Last Answer : (D) 85

Description : A nuclear reactor is a device used to carry out controlled nuclear reaction whereas GM counter is a device used to detect? A. Current B. Voltage C. Nuclear Radiation (Answer) D. power E. None of these

Last Answer : C. Nuclear Radiation (Answer)

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 : Nuclear fuel generally used in reactors is uranium oxide instead of uranium, because the former has higher (A) Melting point, hence can be subjected to higher temperature (B) Density; hence core volume for a given ... be smaller (C) Resistance to effects of irradiation (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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