Physics - Modern Physics Question with Solution | TestHub

Given: Total time, $\mathrm{T}=10$ years Half life, ${\mathrm{T}}_{1/2}=5$ years $\therefore$ No. of half lives, $\mathrm{n}=\frac{10}{5}=2$ From $\frac{\mathrm{N}}{{\mathrm{N}}_0}={\left(\frac{1}{2}\right)}^{\mathrm{n}}$ $\therefore \frac{\mathrm{N}}{{\mathrm{N}}_0}={\left(\frac{1}{2}\right)}^2=\frac{1}{4}$ $\therefore$ After 10 years, ${\frac{1}{4}}^{\text{th }}$ of the original substance will remain. $\Rightarrow \left(1-\frac{1}{4}\right)=\frac{3}{4}\times 100=75\%$ of the fraction would get decayed.