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Standard XII

Physics

Work Done When Force Is Varying

57Co decays b...

Question

$^{57}$ Co decays by electron capture.Its half-life is $272$ days. The activity left after a year is (if present activity is 2 $μ$ Ci)

0.788 μ C i

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0.431 μ C i

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0.39 μ C i

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0.23 μ C i

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Solution

The correct option is A $0.788 μ C i$
Half life $= 272 d a y s$
$λ = \frac{l n 2}{272}$
So, $x = 2 μ c i e^{\frac{- l n 2}{272}} \times 365$

$x = 0.7889 μ c i$

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57Co decays by electron capture.Its half-life is 272 days. The activity left after a year is (if present activity is 2μCi)

The correct option is A 0.788μCiHalf life =272 daysλ=ln2272So, x=2μcie−ln2272×365x=0.7889μci

$^{57}$ Co decays by electron capture.Its half-life is $272$ days. The activity left after a year is (if present activity is 2 $μ$ Ci)

The correct option is A $0.788 μ C i$
Half life $= 272 d a y s$
$λ = \frac{l n 2}{272}$
So, $x = 2 μ c i e^{\frac{- l n 2}{272}} \times 365$

$x = 0.7889 μ c i$