AIIMS 2019 Physics Decay Law MCQ Question

Option A is correct because it accurately derives the percentage decay of active nuclei over a one-hour interval, using the exponential decay formula $N(t) = N_0 e^{-λt}$. The expression $\left( \frac{N_1 - N_2}{N_1} \right) \times 100$ simplifies to $\left( 1 - \frac{1}{e^{λ}} \right) \times 100$, which represents the fraction of nuclei that have decayed in that hour, expressed as a percentage. The other options are not applicable or do not provide additional relevant information, as they are marked as N/A. This question highlights the relationship between decay constant $λ$ and half-life $T_{1/2}$, reinforcing the understanding of radioactive decay processes.