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JEE Main & Advanced JEE Main Paper Phase-I Held on 07-1-2020 Morning

  • question_answer
    The time period of revolution of electron in its ground state orbit in a hydrogen atom is\[1.6\times {{10}^{16}}s\]. The frequency of revolution of the electron in its first excited state (in\[{{s}^{1}}\]) is:        [JEE MAIN Held on 07-01-2020 Morning]

    A) \[1.6\times {{10}^{14}}\]         

    B) \[7.8\times {{10}^{14}}\]

    C) \[5.6\times {{10}^{12}}\]         

    D) \[6.2\times {{10}^{15}}\]

    Correct Answer: B

    Solution :

    [b] \[T\,\,\alpha \,\,{{n}^{3}}\] \[\therefore {{T}_{2}}=8T=8\times 1.6\times {{10}^{16}}s\] \[\therefore v=\frac{1}{{{T}_{2}}}=\frac{1}{8\times 1.6\times {{10}^{16}}}\] \[\approx 7.8\times {{10}^{14}}Hz\]


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