NEET Physics Nuclei Questions Solved


The activity of a radioactive sample is measured as 9750 counts per minute at t = 0 and as 975 counts per minute at t = 5 minutes. The decay constant is approximately

(a) 0.230 per minute             (b) 0.461 per minute
(c) 0.691 per minute             (d) 0.922 per minute

(b) A=A0e-λt975=9750 e-λ×5e5λ=10

5λ=loge10=2.3026 log1010=2.3026λ=0.461

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