The activity of a radioactive material is curie. Its half life is 5 days. The activity will become curie after:
- (A)7 days
- (B)15 days
- (C)25 days
- (D)35 days✓ Correct
Answer: (D)
Solution
Using the radioactive decay law , where day. Given curie and curie. Thus , giving . Taking natural log: , so . Solving: days.
JEE Main · 2022 · 27 Jul 2022 · Shift 2 · Single correct option