JEE Main & Advanced Physics Atomic Physics Question Bank Atomic Structure

  • question_answer
    The wavelength of radiation emitted is \[{{\lambda }_{0}}\]when an electron jumps from the third to the second orbit of hydrogen atom. For the electron jump from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be                                                                               [SCRA 1998; MP PET 2001; MH CET 2003]

    A)            \[\frac{16}{25}{{\lambda }_{0}}\]                                    

    B)            \[\frac{20}{27}{{\lambda }_{0}}\]

    C)            \[\frac{27}{20}{{\lambda }_{0}}\]                                    

    D)            \[\frac{25}{16}{{\lambda }_{0}}\]

    Correct Answer: B

    Solution :

                       \[\frac{1}{\lambda }=R\,\left[ \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right]\] Þ \[\frac{1}{{{\lambda }_{3\to 2}}}=R\,\left[ \frac{1}{{{(2)}^{2}}}-\frac{1}{{{(3)}^{2}}} \right]=\frac{5R}{36}\]                    and \[\frac{1}{{{\lambda }_{4\to 2}}}=R\left[ \frac{1}{{{(2)}^{2}}}-\frac{1}{{{(4)}^{2}}} \right]=\frac{3R}{16}\]            \ \[\frac{{{\lambda }_{4\to 2}}}{{{\lambda }_{3\to 2}}}=\frac{20}{27}\] Þ \[{{\lambda }_{4\to 2}}=\frac{20}{27}{{\lambda }_{0}}\]


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