Go To Your Study Dashboard

Get Answers to all your Questions

header-bg

The decay constant of a radioisotope is $\lambda$ . if $A_{1}$ and $A_{2}$ are its activities at times $t_{1}$ and $t_{2}$ respectively, the number of nuclei which have decayed during the time $\left ( t_{1} \right-_{t_{2}} )$ :

Option 1)
$\lambda \left ( A_{1} \right-A_{2} )$

Option 2)
$A_{1}t_{1}-A_{2}t_{2}$

Option 3)
$A_{1}-A_{2}$

Option 4)
$\left ( A_{1} \right-A_{2} )/\lambda$

Answers (1)

best_answer

As we learnt in

Number of nuclei after disintegration -

$N=N_{0}e^{-lambda t}$ or $A=A_{0}e^{-lambda t}$

- wherein

Number of nucleor activity at a time is exponentional function

Law of radioactivity -

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

- wherein

Ratio of disintegration is propotional to number of nuclei

$lambda$ = disintegration constant

$A_{1}=A_{o}\cdot e^{-\lambda t_{1}} \: \: \Rightarrow N_{1}=\frac{A_{1}}{\lambda }=\frac{A_{o}}{\lambda }\cdot e^{-\lambda t_{2}}$

$A_{2}=A_{o}\cdot e^{-\lambda t_{2}} \: \: \Rightarrow N_{2}=\frac{A_{2}}{\lambda }=\frac{A_{o}}{\lambda }\cdot e^{-\lambda t_{1}}$

Number of nuclei decayed between t₁ and t₂ = N₁-N₂= $\frac{A_{1}-A_{2}}{\lambda }$

Option 1)

$\lambda \left ( A_{1} \right-A_{2} )$

Incorrect

Option 2)

$A_{1}t_{1}-A_{2}t_{2}$

Incorrect

Option 3)

$A_{1}-A_{2}$

Incorrect

Option 4)

$\left ( A_{1} \right-A_{2} )/\lambda$

Correct

Posted by

divya.saini

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

Want a career in medicine without NEET? Consider paramedical courses after Class 12

anam-khan

AFMC hikes MBBS seat leaving bond penalty, mandates 7 years of commission service

anam-khan

‘Patience and not backing down’: Kabir Paharia’s SC fight eases MBBS admissions for disabled candidates

Latest Question