Question

Control rods of calcium or boron are inserted into the nuclear reactor:
(A) To absorb neutrons
(B) To absorb gamma particles
(C) As coolants
(D) To induce the nuclear fission

Answer 1

Nuclear reactor is a reactor in which nuclear reactions are carried out for constructive purposes. Thus, the rods of calcium or boron are inserted to assist the functions of nuclear reactors.

Complete step by step answer:
As we know that a nuclear reactor is a powerful device wherein the nuclear energy produced is utilized for constructive purposes. A nuclear reactor is based upon controlled nuclear chain reaction. Nuclear reactors are used at nuclear power plants to generate electricity and in nuclear marine propulsion & Heat from nuclear fission is passed to working fluid which in
Turn runs through steam turbines that either drive a ship's propeller or turn electrical generator shafts. Nuclear Reactors are used to produce neutron beams of high intensity which are used in the treatment of cancer and nuclear research. The main a nuclear reactor is given below:
1.Nuclear Fuel: It is a fissionable material to
be used for the fission process to take place commonly used fuels in a nuclear
reactors are ${U^{233}},{U^{235}},P{u^{239}}$ etc.
2.Moderator: - its function is to slow down
the fast moving secondary neutrons produced during the fission. The material of moderator used should be light and it should not absorb neutrons : i.e. – graphite, deuterium , and paraffin
Control Roes: they are used to capture slow neutrons . To control the chain reaction from becoming violent, rods of boron calcium or cadmium (called control rods)are inserted in the holes of the reactor core , up to a desirable length.
3.Coolant: A substance which is used to remove the heat produced and transfer it to the surroundings called coolant.
4.shielding : The whole reactor is protected with Concrete walls so that radiation emitted during nuclear reactions may not produce harmful effects.
From the above, we got to know that un control rods are used to absorb neutrons. So the calcium or boron control rods are inserted into the nucleon reactor to absorb neutrons,

So, the correct answer is Option A .

Note:
In an atom bomb, nuclear chain reaction is uncontrolled whereas in a nuclear reactor , nuclear chain reaction is controlled An unavoidable feature of a reactor is the accumulation of radioactive waste. This waste of a nuclear reactor is extremely hazardous to all forms of life on earth.