question_answer

A radioactive sample at any instant has its disintegration rate 5000 disintegrations per minute. After 5 min, the rate is 1250 disintegrations per minute. Then, the decay constant (per minute) is [AIEEE 2003]

A) \[0.4\] In 2

B) \[0.2\] In 2

C) \[0.1\] In 2

D) \[0.8\] In 2

Correct Answer: A

Solution :

[a] Given,

where,  is decay constant per minute.