Two radioactive substances A and B have decay constants and respectively

PHYSICS · Single correct · CBSE · Physics · Nuclei · Nuclei

Problem

Two radioactive substances A and B have decay constants

5\lambda

and

\lambda

respectively. At

t=0

, a sample has the same number of the two nuclei. The time taken for the ratio of the number of nuclei to become

\left(\frac{1}{e}\right)^2

will be: (1)

1/2\lambda

(2)

1/4\lambda

(3)

1/\lambda

(4)

2/\lambda