Question

Two radioactive materials $X_1$ $X_1$ contain same number of nuclei. If $6\lambda s^{-1}$ and $4\lambda s^{-1}$ are the decay constants of $X_1$ and $X_2$ respectively, the ratio of number of 48 nuclei, undecayed of $X_1$ to that of $X_2$ will be (1/e) after a time.

• A. $\frac{1}{2\lambda }sec$
• B. $\frac{1}{10\lambda }sec$
• C. $\frac{1}{5\lambda }$
• D. $\frac{1}{8\lambda }sec$

Answer 1

Answer: (A)