Radioactive decay to 1/32 initial: number of half-lives: MCQ with Answer and Explanation

Radioactive decay to 1/32 initial: number of half-lives:
A. 4
B. 5
C. 3
D. 6
Answer: Option B
Solution (By JKSSB Mock Tests)
(1/2)ⁿ = 1/32 ⇒ 2ⁿ = 32 ⇒ n = 5 half-lives. Exponential decay calculation. Memory aid: '1/2ⁿ remaining; 1/32 = 1/2⁵ ⇒ 5 half-lives'. Radioactivity arithmetic frequently tested in competitive exams.

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The time period of a simple pendulum is 2 s at a place where g=9.8 m/s². Its length is about
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B. 0.5 m
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Correct Answer: Option C


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