InterviewSolution
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InterviewSolution
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A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial activity is ten times the permissible value, after how many days will it be safe to enter the roomA. 1000 daysB. 300 daysC. 10 daysD. 100 days |
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Answer» Correct Answer - D Activity `(-(dN)/(dt)) prop N` `N = N_(0) ((1)/(2))^(n) rArr (N)/(N_(0)) = ((1)/(2))^(n)` `(1)/(10) = ((1)/(2))^(n) rArr 10 = 2^(n)` `log 10 = n log 2 rArr n = (1)/(0.301) = 3.32` `t = n xx t_(1//2) = 3.32 xx 30 = 99.6` days |
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