Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • A radioactive isotope has a, half-life of 5 years. After how much time it its activity reduced to 3.125 % of its original activity?Option: 1 20 years

A radioactive isotope has a, half-life of 5 years. After how much time it its activity reduced to 3.125 % of its original activity?

Option: 1

20 years 


Option: 2

40 years 


Option: 3

25 years 


Option: 4

24 years 


Answers (1)

best_answer

\mathrm{we \ know, \left(\frac{R}{R_0}\right)=\left(\frac{1}{2}\right)^n } \\ {Given, \frac{R}{R_0}=3.125 \%=3.125 \times \frac{1}{100} }
\mathrm{\begin{aligned} & \frac{3 \cdot 125}{100}=\left(\frac{1}{2}\right)^n \text { or } \frac{1}{32}=\left(\frac{1}{2}\right)^n \\ & \left(\frac{1}{2}\right)^5=\left(\frac{1}{2}\right)^n \end{aligned} }
Given, n=5 years

As, n=t/T=5

t=25 years

 

Posted by

qnaprep

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

Karnataka NEET UG 2026: KEA allows candidates without seats in stray round, extends choice filling to Oct 19
anam-khan

Maharashtra NEET Counselling: Pvt medical colleges move HC, want institute rounds of MBBS, MD admissions back
anam-khan

NEET UG 2026: CBI files supplementary chargesheet in paper leak case

Latest Question