NEET Sample Paper NEET Sample Test Paper-25

  • question_answer
    The total energy of an electron in the first excited; state of hydrogen is about -3.4 eV. Its kinetic energy in this state is

    A)  -3.4 eV

    B)  -6.8 eV

    C)  6.8 eV

    D)  3.4eV

    Correct Answer: D

    Solution :

     Kinetic energy of electron \[K=\frac{Z{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\] Potential energy of electron \[U=-\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Z{{e}^{2}}}{r}\] \[\therefore \]Total energy \[E=K+U=\frac{Z{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}-\frac{Z{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\] or \[E=-\frac{Z{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\] or \[E=-K\] or \[K=-E=-(-3.4)=3.4\,eV\]


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