Question

Two radioactive sources A and B initially contain equal number of radioactive atoms. Source A has a half-life of 1 hour and source B has a half-life of 2 hours.At the end of 2 hours, the ratio of the rate of disintegration of A to that of Bis :

(A) 1 : 2 

(B) 2 : 1

(C) 1 : 1 

(D) 1 : 4

Answer 1

Correct Answer is: (C) 1 : 1 

No. of atoms of A after 2hrs. = N0/4

No of atoms of B after 2hrs. = N0/2