Question

Two radioactive species A, B having No, = 4Nowith half-life periods 3and 9 min respectively. How much time it will take to make N. = N, ?​

Answer 1

Explanation:

Correct option is

D

2λ1

Decay equation is given by N=Noe−λt

Where, λ is Decay constant; N is number of atom at time t

So, number of atom of A is given by, NA=Noe−5λt

And that of B are given by, NB=Noe−λt

Taking ration we get: NBNA=e−4λt

Given that: NBNA=e−2

So, this will happen when, t=2λ1