Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • Stuck here, help me understand: - Atoms And Nuclei - JEE Main-4

At some instant, a radioactive sample S_{1} having an activity 5 μCi has twice the
number of nuclei as another sample S_{2} which has an activity of 10 μCi. The half
lives of S_{1} and S_{2} are :

  • Option 1)

    20 years and 5 years, respectively

  • Option 2)

    20 years and 10 years, respectively

  • Option 3)

    5 years and 20 years, respectively

  • Option 4)

    10 years and 20 years, respectively

 

Answers (2)

best_answer

As we have learned

Law of radioactivity -

-\frac{dN}{dt}= \lambda N

- wherein

Ratio of disintegration is propotional to number of nuclei         

\lambda= disintegration constant

 

Activity = \lambda N

\lambda_{1} N_{1}= 5\mu Ci \Rightarrow( \frac{\lambda _{1}N_{1}}{\lambda _{2}N})=1/2

\lambda_{2} N_{2}= 10\mu Ci

also N_{2}= N_{1}=/2 \Rightarrow \frac{\lambda _{1}}{\lambda _{2}}=1/4

or t_{2}/t_{1}=1/4

half life of s_{1}= 20years  and s_{2}= 5 years 

 

 

 

 

 


Option 1)

20 years and 5 years, respectively

This is correct

Option 2)

20 years and 10 years, respectively

This is incorrect

Option 3)

5 years and 20 years, respectively

This is incorrect

Option 4)

10 years and 20 years, respectively

This is incorrect

Posted by

Aadil

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2024 session 2 result date announced; Steps to check NTA session 2 scores
anam-khan

JEE Main 2024 session 2 final answer key soon at jeemain.nta.ac.in; result on April 25
anam-khan

JEE Main 2024 Session 2: Last day to challenge answer key today

Latest Question