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Question
Explain the process of controlled and uncontrolled chain reactions.
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Solution
- Controlled chain reaction
- In the controlled chain reaction, the number of neutrons released is maintained to be one. This is achieved by absorbing the extra neutrons with a neutron absorber leaving only one neutron to produce further fission.
- Thus, the reaction is sustained in a controlled manner. The energy released due to a controlled chain reaction can be utilized for constructive purposes.
- The controlled chain reaction is used in a nuclear reactor to produce energy in a sustained and controlled manner.
- Uncontrolled chain reaction:
- In the uncontrolled chain reaction, the number of neutrons multiplies indefinitely and causes fission in a large amount of the fissile material.
- This results in the release of a huge amount of energy within a fraction of a second.
- This kind of chain reaction is used in the atom bomb to produce an explosion.

Uncontrolled chain reaction
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