InterviewSolution
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InterviewSolution
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Derive expression for the de-Broglie wavelength of an electron moving under a potential difference of V volt. Name an experiment which verified the wave nature of electrons. |
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Answer» Solution :Wavelength associated with a moving electron Suppose an electron starting from rest falls through a potential difference V Let charge on electron = e Mass of electron = m Velocity acquired by the electron in falling through a potential difference, V = v WORK done on the electrons `=1/2mv^(2)` Obviously, `1/2mv^(2) =EV` or `v=sqrt((2eV)/m)`...........(1) If `LAMBDA` is the wavelength associated with the electron, then according to de-Broglie WAVE equation. `lambda =h/(mv)` `=h/(msqrt(2eV)/m) = h/sqrt(2meV)` Substituting the values of h,m and e. we get `lambda =(12.27)/sqrt(V) Å, (10^(-10) m =1 Å)` The wave NATURE of electrons was verified by Davisson and Gerner experiment. |
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