JEE Main & Advanced Sample Paper JEE Main Sample Paper-43

  • question_answer
    At what temperature will the translational kinetic energy of H-atom equal to that for H-atom of first line Lyman transition? (Given \[{{N}_{A}}=6\times {{10}^{23}}\])

    A)  780 K                         

    B)  \[1.32\times {{10}^{5}}\,K\]

    C)  \[7.84\times {{10}^{4}}K\]            

    D)  \[1900\,K\]

    Correct Answer: C

    Solution :

                 \[q'=(Q-q)\] where,      \[\therefore \] \[F=\frac{1}{r\pi {{\varepsilon }_{0}}}\frac{Q(Q-q)}{{{R}^{2}}}\] \[\frac{dF}{dq}=0\] \[\frac{d}{dq}\,\left[ \frac{Kq(Q-q)}{{{R}^{2}}} \right]=0\] \[\Rightarrow \] \[[Q-2q]=0\]  \[q=\frac{Q}{2}\] of H atom \[U=\frac{{{Q}^{2}}}{2C}\] \[C'=KC\] \[U'=\frac{{{Q}^{2}}}{2C'}=\frac{1}{2}\,\frac{{{Q}^{2}}}{KC}\]

You need to login to perform this action.
You will be redirected in 3 sec spinner