Nuclear Physics And Radioactivity Question 73
Question: After 280 days, the activity of a radioactive sample is 6000 dps. The activity reduces to 3000 dps after another 140 days. The initial activity of the sample in dps is [IIT-JEE (Screening) 2004]
Options:
A) 6000
B) 9000
C) 3000
D) 24000
Show Answer
Answer:
Correct Answer: D
Solution:
Here the activity of the radioactive sample reduces to half in 140 days. Therefore, the half life of the sample is 140 days. 280 days is it?s two half lives. So before two half lives it?s activity was $ (2^{2}\times $ present activity). \ Initial activity = $ 2^{2}\times 6000=24000,dps. $
BETA
