Wave property of electron implies that they will show diffraction effected . Davisson and Germer demonstrated this by diffracting electron from crystals . The law governing the diffraction from a crystals is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructiely

Electron accelerated by potential `V` are diffracted from a crystal if `d = 1 Å and i = 30^(@), V` should be about `(h = 6.6 xx 10^(-34) Js, m_(e) = 9.1 xx 10^(-31) kg , e = 1.6 xx 10^(-19)C)`

Options

A. `2000 V`
B. `50 V`
C. `500 V`
D. `1000 V`

Answer

B

Explanation

`2d cos I =n lambda implies 2d cos i=(h)/sqrt(meV)implies V=50` volt