Tag: nuclear physics

Questions Related to nuclear physics

When the reactor shuts down why does it require cooling?

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. To cool the reactor from chain reaction

  2. To cool the reactor from fission reaction

  3. Both $(1)$ and $(2)$

  4. None of these

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Correct Option: C
Explanation:
Reactor requires cooling
  • To cool the reactor from chain reaction
  • To cool the reactor from fission reaction

The nuclear reactor of the power plant must be shielded with ______walls. 

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. Lead

  2. Steel

  3. Both

  4. None

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Correct Option: C
Explanation:

The nuclear reactor of the power plant must be shielded with lead and steel walls so as to stop radiations from escaping out to the environment during its normal operation.

The nuclear reactor at Kaiga is a :

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. research reactor

  2. fusion reactor

  3. breedor reactor

  4. power reactor

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Correct Option: D
Explanation:

The nuclear reactor at Kaiga is Kaiga Atomic Power Station.

A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity. 
The use of nuclear reactor for electricity and power generation classifies it as a power reactor.

Nuclear power reactor is based on the principle of.

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. Exothermic chemical reactions

  2. Endothermic chemical reactions

  3. Controlled nuclear fission

  4. Thermonuclear fusion

Show answer
Correct Option: C
Explanation:

Controlled nuclear fission 

In a nuclear power reactor, materials that may undergo nuclear fission is used in a controlled manner to produce a steady state supply of heat. 

A nuclear reactor must consist of which of the following parts?
I. Electric generator
II. Fissionable fuel elements
III. Moderator

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. I only

  2. III only

  3. I and II only

  4. II and III only

  5. I, II and III

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Correct Option: D
Explanation:

A nuclear reactor must consist:
 II. Fissionable fuel elements such as U-235 and Pu-239.
III. Moderator (heavy water) which slows down the speed of neutrons.

Boron rods, in a nuclear reactor, are used as.

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. moderator

  2. Protective shield

  3. Coolants

  4. Control rods

Show answer
Correct Option: A
Explanation:

Control rods are used in nuclear reactors to control the fission rate of uranium and plutonium. It is achieved by removing the excess neutrons from the reactor core. The only way to remove the excess neutrons through some elements which posses strong neutron absorption capacity. One such element is boron. By regulating the movement or insertion of boron rods into the reactor core while fission process is in progress, the excess neutrons produced during the chain reaction are absorbed by boron which rods regulate the availability of neutron. 


Best neutron moderator is.

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. Beryllium oxide

  2. Pure water

  3. Graphite

  4. Heavy water

Show answer
Correct Option: B
Explanation:

Pure water 

Neutron moderator is a medium that reduces the speed of fast neutrons.  Commonly used moderator is regular (light)  water(around 75% of the worlds reactors) 

A disadvantage of nuclear power is - 

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. it produces carbon dioxide which is responsible for global warming

  2. it produces toxic waste

  3. it affects the ozone layer

  4. it requires large amounts of fuel to produce a small amount of energy

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Correct Option: B
Explanation:

Nuclear fuels are non-renewable sources of energy and large amount of radioactive materials, which are toxic in nature, are released in the environment which are extremely hazardous to the health of living being for thousands of years.

Cadmium rods are used as moderators in a nuclear reactor.

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. True

  2. False

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Correct Option: B
Explanation:

Commonly used moderators include regular(light) water (roughly 75% of the world's reactors), solid graphite (20% of reactors) and heavy water (5% of reactors). Beryllium has also been used in some experimental types, and hydrocarbons have been suggested as another possibility.

Best moderator for neutron is

chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

  1. berillium oxide

  2. pure water

  3. heavy water

  4. graphite

Show answer
Correct Option: C
Explanation:
Heavy water is best moderator
Moderator-This is a material which slows down the medium speed of neutrons produced by fission