Question

By what potential difference must an electron (m = 9.11*10^-31 kg) be accelerated to have a wavelength of 5.16*10^-12 m? i keep getting wied answers, thanks in advance.

Answer 1

For an electron accelerated by potential difference V the de broglie wavelength is related to V as

$\lambda = \frac{h}{\sqrt{2meV}}$ .......... 1

we have

$\lambda= 5.16 * 10^{-12} m$

Substituting these values in equation 1

$5.16 * 10^{-12}= \frac{1.227 *10^{-9}}{\sqrt{V}}$

${\sqrt{V}} = 237.8$

We are given