Two radioactive materials $M_1$ and $M_2$ have decay constants $9 \lambda$ and $\lambda$ respectively. Initially,they have the same number of nuclei. The ratio of the number of nuclei of $M_1$ to that of $M_2$ will be $\frac{1}{e}$ after a time interval of:

  • A
    $\frac{9}{10 \lambda}$
  • B
    $\frac{1}{10 \lambda}$
  • C
    $\frac{1}{9 \lambda}$
  • D
    $\frac{1}{8 \lambda}$

Explore More

Similar Questions

The activity of a radioactive sample is measured as $N_0$ counts per minute at time $t=0$,and $\frac{N_0}{e}$ counts per minute at time $t=3$ minutes. The activity reduces to half its value in time (in minutes) is:

Radioactive nuclei $A$ and $B$ disintegrate into $C$ with half-lives $T$ and $2T$. At $t = 0$,the number of nuclei of each $A$ and $B$ is $x$. The number of nuclei of $C$ when the rate of disintegration of $A$ and $B$ are equal is:

Difficult
View Solution

$A$ count rate meter shows a count of $240$ per minute from a given radioactive source. One hour later,the meter shows a count rate of $30$ per minute. The half-life of the source is .......... $min$.

If the mass of a radioactive sample is doubled,the activity of the sample and the disintegration constant of the sample are respectively

The half-life of a radioactive substance is $20 \, \text{minutes}$. The approximate time interval $(t_2 - t_1)$ between the time $t_2$ when $\frac{3}{4}$ of it has decayed and time $t_1$ when $\frac{1}{4}$ of it has decayed is:

Difficult
View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo