Question
Question: The count rate of a Geiger- Muller counter for the radiation of a radioactive material of half life ...
The count rate of a Geiger- Muller counter for the radiation of a radioactive material of half life of 30 minutes decreases to 5s−1after 2 hours. The initial count rate was.
A
25s−1
B
80s−1
C
625s−1
D
20s−1
Answer
80s−1
Explanation
Solution
A=A0(21)t/T1/2⇒5=A0(21)302×60=16A0⇒A0=80sec−1