First slide

Radio activity

Question

Half-life of a substance is 10 years. In what time, it becomes $\frac{1}{4} th$ part of the initial amount?

Easy

A

5 years
B

10 years
C

20 years
D

None of these

Solution

$N = N_{0} e^{- t / T_{1 / 2}} \Rightarrow \frac{1}{4} = e^{- t / 10} \Rightarrow {(\frac{1}{2})}^{2} = \frac{1}{e^{t / 10}} \Rightarrow t = 20 years$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App