$A$ and $B$ are two radioactive substances whose half lives are $1$ and $2$ years respectively. Initially $10\, g$ of $A$ and $1\,g$ of $B$ is taken. The time (approximate) after which they will have same quantity remaining is ........... $years$

Consider a radioactive material of half-life $1.0 \, minute$. If one of the nuclei decays now, the next one will decay

Two radioactive isotopes $P$ and $Q$ have half Jives $10$ minutes and $15$ minutes respectively. Freshly prepared samples of each isotope initially gontain the same number of atoms. After $30$ minutes, the ratio $\frac{\text { number of atoms of } P}{\text { number of atoms of } Q}$ will be

A radioactive sample disintegrates via two independent decay processes having half lives $T _{1 / 2}^{(1)}$ and $T _{1 / 2}^{(2)}$ respectively. The effective half- life $T _{1 / 2}$ of the nuclei is

The sample of a radioactive substance has $10^6$ nuclei. Its half life is $20 \,s$. The number of nuclei that will be left after $10 \,s$ is nearly ...... $\times 10^5$

The fraction $f$ of radioactive material that has decayed in time $t$, varies with time $t$. The correct variation is given by the curve