Home
Class 12
PHYSICS
The decay constant of a radioactive elem...

The decay constant of a radioactive element is definded as the reciprocal of the time interval after which the number of atoms of the radioactive element falls to nearly

A

50% of its original number

B

36.8% of its original number

C

63.2% of its original number

D

75% of the original number

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • CIRCULAR MOTION

    NIKITA PUBLICATION|Exercise Multiple Choice Question|421 Videos

Similar Questions

Explore conceptually related problems

The decay constant of a radioactive element is defined as the reciprocal of the time interval after which the number of atoms of the radioactive element falls to neraly

The decay constant of a radioactive sample

Why do radioactive element decay?

The rate of decay of radioactive element

99 % of a radioactive element will decay between

The decay constant of a radioactive element is 1.05xx10^(-4) / year. What is its half life ?

The decay of a radioactive element follows first order kinetic. Thus,

NIKITA PUBLICATION-ATOMS, MOLECULES AND NUCLEI-MCQs
  1. A radioactive decay rate of 1 curie represents

    Text Solution

    |

  2. When a nucleus undergoes radioactive decay, its new mass number is

    Text Solution

    |

  3. The decay constant of a radioactive element is definded as the recipro...

    Text Solution

    |

  4. The half life of a radioactive element is T and its initial activity a...

    Text Solution

    |

  5. The decay constant of the end product of a radioactive series is

    Text Solution

    |

  6. Half-life-speed of lead is:

    Text Solution

    |

  7. The half life of 1 gm of a radioactive element of atomic weight M is T...

    Text Solution

    |

  8. Rate of disintegration per atom is called

    Text Solution

    |

  9. The value of decay constant is independent of

    Text Solution

    |

  10. Which of the following is the unit of activity of a radiactive element...

    Text Solution

    |

  11. Half-life of radioactive element depend upon

    Text Solution

    |

  12. N atoms of a radioactive substance emit n alpha-particles per second. ...

    Text Solution

    |

  13. If the half life of radium is 1620 years then its decay constant is

    Text Solution

    |

  14. A radioactive substance decay to 1/5 of its original value in 56 days....

    Text Solution

    |

  15. The activity of a radioactive substance is readuced by 80% in 100 days...

    Text Solution

    |

  16. The half-life period of radium is 1600 years. The fraction of a sample...

    Text Solution

    |

  17. A sample contains 10 mg of radioactive material of half life 270 days....

    Text Solution

    |

  18. If a radioactive material has half life of one year, a sample will be ...

    Text Solution

    |

  19. A radioactive substance decays to 1/64 of its initial quantity in 30 d...

    Text Solution

    |

  20. Three specimens A, B, C of same radioactive element has activities 1 m...

    Text Solution

    |