Nuclear Physics And Radioactivity Question 302
Question: The counting rate observed from a radioactive source at t=0 second was 1600 counts per second and at t=8 seconds it was 100 counts per second. The counting rate observed, as counts per second at t=6 seconds, will be [MP PET 1996; UPSEAT 2000; Pb. PET 2004; Kerala PET 2005]
Options:
A) 400
B) 300
C) 200
D) 150
Show Answer
Answer:
Correct Answer: C
Solution:
$ A=A_{0}{{( \frac{1}{2} )}^{\frac{t}{{T_{1/2}}}}} $
Þ $ 100=1600,{{( \frac{1}{2} )}^{\frac{8}{{T_{1/2}}}}} $
Þ $ {T_{1/2}}=2sec $ Again at t = 6 sec, $ A=1600,{{( \frac{1}{2} )}^{\frac{6}{2}}}=200 $ counts/sec
BETA
