A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If c and m are charge and mass of an electron repectively, then the value of `h//lambda` (where `lambda` is wavelength associated with electron wave) is given by :

Options

A. `sqrt(meV)`
B. `sqrt(2meV)`
C. meV
D. `2meV`

Answer

B

Explanation

As electron of charge .e. is passed through .V. volts , kinetic nergy of electron will be V.
Wavelenght of electron will be `(lambda) = (h)/(sqrt(2m.K.E))`
`lambda = (h)/(sqrt(2meV)) rArr therefore (h)/(lambda) = sqrt(2meV)`