Home
Class 12
PHYSICS
Half life of a radioactive substance A i...

Half life of a radioactive substance A is two times the half life of another radioactive substance B. Initially, the number of nuclei of A and B are `N_(A) and N_(B)` respectively. After three half lives of A, number of nuclei of both are equal. Then the ratio `(N_(A))/(N _(B))` is

A

`(1)/(3)`

B

`(1)/(6)`

C

`(1)/(8)`

D

`(1)/(4)`

Text Solution

Verified by Experts

The correct Answer is:
C
Three half lives of A are equivalent to six half lives of B. As number of nuclei left are equal in the two cases.
Therefore, `N_(A)((1)/(2))^(3)=N_(B)((1)/(2))^(6)`
`(N_(A))/(N_(B))=((1//2)^(6))/((1//2)^(3))=((1)/(2))^(3)=(1)/(8)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ATOMS AND NUCLEI

    MTG GUIDE|Exercise NEET CAFÉ (TOPICWISE PRACTICE QUESTIONS)(NUCLEAR REACTION)|6 Videos

  • ATOMS AND NUCLEI

    MTG GUIDE|Exercise NEET CAFÉ (TOPICWISE PRACTICE QUESTIONS)(NUCLEAR FISSION AND FUSION)|9 Videos

  • ATOMS AND NUCLEI

    MTG GUIDE|Exercise NEET CAFÉ (TOPICWISE PRACTICE QUESTIONS)(NUCLEAR FORCE)|2 Videos

  • CURRENT ELECTRICITY

    MTG GUIDE|Exercise MCQs AIPMT / NEET|32 Videos

Similar Questions

Explore conceptually related problems

Half-life of a radioactive substance is T. At time t_1 activity of a radioactive substance is R_1 and at time t_2 it is R_2 . Find the number of nuclei decayed in this interval of time.

The half life of a radioactive element A is same as mean life time of another radioactive element B.Initially, both have same number of atoms. B decays faster than A . Why?

Knowledge Check

  • Half-life of a radioactive substance A is two times the half-life of another radioactive substance B . Initially, the number of A and B are N_(A) and N_(B) , respectively . After three half-lives of A , number of nuclei of both are equal. Then, the ratio N_(A)//N_(B) is .

    A
    `1//4`
    B
    `1//8`
    C
    `1//3
    D
    `1//6`

  • Half life of a radioactive substance with progress of time

    A
    increase
    B
    decrease
    C
    remain same
    D
    none

  • The half-life of a radioactive substance is 10 days. This means that

    A
    the substance completely disintergrates in 20 days
    B
    the substance completely disintergrates in 40 days
    C
    `1//8` part of the mass of the substance will be ledt intact at the end of 40 days
    D
    `7//8` part of the mass of the substance disintegrates in 30 days

    • Similar Questions

    Explore conceptually related problems

    The half life of a radioactive element A is same as the mean life time of another radioacitve element B. Initially , both have same number of atoms, B decay faster than A. Why ?

    N atoms of a radioactive substance emit n alpha -particles per second. The half life of the radioactive substance is

    The half life of a radioactive substance is 24 hours. Time required for 12.5% of the original radioactive substance W remain is

    The half life of a radioactive substance is T_(0) . At t=0 ,the number of active nuclei are N_(0) . Select the correct alternative.

    Two radioactive substances X and Y originally have N_(1) and N_(2) nuclei respectively. Half life of X is half of the half life of Y. After three half lives of Y, number of nuclei of both are equal. (N_(1))/(N_(2)) The ratio N will be equal to :

    Home
    Profile