CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2010

  • question_answer
    If m is the mass of an electron and c is the speed of light, the ratio of the wavelength of a photon of energy E to that of the electron of the same energy is  

    A)  \[c\sqrt{\frac{2m}{E}}\]              

    B)         \[\sqrt{\frac{2m}{E}}\]

    C)  \[\sqrt{\frac{2m}{cE}}\]              

    D)         \[\sqrt{\frac{m}{E}}\]

    E)  \[\sqrt{\frac{cm}{E}}\]

    Correct Answer: A

    Solution :

    Energy, \[E=\frac{hc}{{{\lambda }_{p}}}\] Or           \[{{\lambda }_{p}}=\frac{hc}{E}\] and        \[{{\lambda }_{e}}=\frac{h}{p}=\frac{hc}{\sqrt{2mE}}\] \[\therefore \]  \[\frac{{{\lambda }_{p}}}{{{\lambda }_{e}}}=\frac{E}{\frac{h}{\sqrt{2mE}}}\] Or           \[\frac{{{\lambda }_{p}}}{{{\lambda }_{e}}}=\frac{c\sqrt{2mE}}{E}=c\sqrt{\frac{2m}{E}}\]            


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