An electron beam can undergo defraction by crystals .Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to `1.54 Å`

Explanation

For an electron , `1/2 mu^2 =e.V`
and ` lambda = ( h)/( mu)`
Thus ` 1.2 m h^2 /( m^2lambda^2) = e. V`
or ` V= 1/2 h^2/( mlambda^2 . E)`
` = (1 xx ( 6.62 xx 10^(-34)))/(2 xx 9. 108 xx 10^(-31) xx ( 1.54 xx 10^(-10))^2 xx 1. 602 xx 10^(19))`
` 63.3 ` volt .