Home
Class 12
PHYSICS
In a nuclear reactor, moderators slow do...

In a nuclear reactor, moderators slow down the neutrons which come out in a fission process. The moderator used have light nuclei. Heavy nuclei will not serve the purpose because

A

they will break up

B

elastic collision of neutrons with heavy nuclei will not slow them down.

C

the net weight of the reactor would be unbearably

D

substances with heavy nuclei do not occur in liquid or gaseous state at room temperature.

Text Solution

Verified by Experts

The correct Answer is:
B
Conceptual
Promotional Banner

Topper's Solved these Questions

  • NUCLEI

    NARAYNA|Exercise ASSERTION & REASON|5 Videos

  • NUCLEI

    NARAYNA|Exercise EXERCISE-3|30 Videos

  • NUCLEAR PHYSICS

    NARAYNA|Exercise LEVEL-II-(H.W)|9 Videos

  • RAY OPTICS AND OPTICAL INSTRAUMENTS

    NARAYNA|Exercise EXERCISE- 4 One or more than one correct answer type|13 Videos

Similar Questions

Explore conceptually related problems

Calcium rods are used in nuclear reactors to slow down the neutrons taking part in the fission process

Substance used to slow down the fast neutrons released during nuclear fission is called?

(a) What are thermal neutrons in the context of nuclear fission ? (b) What role does a moderator play in a nuclear reactor ?

Moderator is used in a nuclear to slow down fast neutrons generated after a fission event in the reactor consider a fast neutron (mass m_(n) ) moving at speed v. The neutron hits a moderator nucleus (Mass M), which is originally static, and gets scattered elastically by 180^(@) (a) Find te rato of kinetic energy of the neutron after and before collision. (b) Show that when Mgtgtm_(n) , neutron does not lose much energy and therefore, a moderator should have a small mass number.

Which of the following is used as a moderator in nuclear reactors ?

NARAYNA-NUCLEI -EXERCISE-4
  1. Tritium is an isotope of hydrogen whose nucleus triton contains 2 neut...

    Text Solution

    |

  2. Heavy stable nuclei have more neutrons than protons. This is because o...

    Text Solution

    |

  3. In a nuclear reactor, moderators slow down the neutrons which come out...

    Text Solution

    |

  4. 50% of a radio active substance decays in 5 hours. The time required f...

    Text Solution

    |

  5. 4 grams of radioactive substance A left 1//2 gm after some time . 1 gr...

    Text Solution

    |

  6. One mole of alpha emitter of half life equal to 2 days was placed in a...

    Text Solution

    |

  7. 3 ruthuerfords of a radio active isotope of half-life equal to 3 days ...

    Text Solution

    |

  8. The half life of a radio active substance is 6 hours. The amount of th...

    Text Solution

    |

  9. The radio active nuclides A and B have half lives t and 2t respectivey...

    Text Solution

    |

  10. 20% of a radio active element disintergrates in 1 hr. The percentage o...

    Text Solution

    |

  11. The C^(14) to C^(12) ratio in a certain piece of wood is 25% of that i...

    Text Solution

    |

  12. A radiactive sample decays by two different processes .Half - life for...

    Text Solution

    |

  13. The age of the wood if only 1//16 part of original C^(14) is present ...

    Text Solution

    |

  14. A piece of wood is found to have the (C^(14))/(C^(12)) ratio to be 0.5...

    Text Solution

    |

  15. A piece of wood collected from cro-Magnon caves gave 4 disintergration...

    Text Solution

    |

  16. The number of U^(238) nuclei in a rock sample equal to the number of P...

    Text Solution

    |

  17. Equal masses of two samples of charcoal A and B are burnt separately a...

    Text Solution

    |

  18. The half life of a radioactive substance is 20 minutes . The approxima...

    Text Solution

    |

  19. A charged capacitor of capacitance C is discharged through a resistanc...

    Text Solution

    |

  20. Uranium- 238 decays to thorium-234 with half-life 5xx10^(9) yr. The re...

    Text Solution

    |