WB JEE Medical WB JEE Medical Solved Paper-2007

  • question_answer
    The half-life period of radioactive element is 140 days. After 560 days, 1 gram of element will reduce to

    A)  \[\frac{1}{2}g\]                               

    B)  \[\frac{1}{4}g\]

    C)  \[\frac{1}{8}g\]                               

    D)   \[\frac{1}{16}g\]

    Correct Answer: D

    Solution :

                     \[T=n\times {{t}_{1/2}}\] Where, \[{{t}_{1/2}}=\]half-life period, \[n=\frac{T}{{{t}_{1/2}}}=\frac{560}{140}=4\]                 Now, \[{{N}_{t}}={{N}_{0}}{{\left( \frac{1}{2} \right)}^{n}}\]                                 \[=1\times {{\left( \frac{1}{2} \right)}^{4}}=\frac{1}{16}g\]


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