1.

A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference of V esu. If e and m are charge and mass of the electron respectively, then the value of `h//lamda` (where `lamda` is the wavelength associated with the electron wave) is given byA. `me V`B. `2 me V`C. `sqrt(me V)`D. `sqrt(2 meV)`

Answer» Correct Answer - D
`lamda = (h)/(p) or (h)/(lamda) = p = mv`
`KE = (1)/(2)mv^(2)` so that `v = sqrt((2KE)/(m)) " But " KE = eV`
`:. v = sqrt((2eV)/(m)) :. (h)/(lamda) = mv = m sqrt((2eV)/(m)) = sqrt(2meV)`


Discussion

No Comment Found

Related InterviewSolutions