Question

An electron in order to have a wavelength of 500 angstrom,through what potential difference it must pass?

Answer 1

hc / lamda = ev             (v = potential difference)
6.626*10^-34*3*10^8/5*10^-8 = 1.6*10^-19*v
v = 24.85volts

Answer 2

Answer:

It will pass through the potential of 24.81 eV.

Explanation:

Wavelength of an electron = $\lambda =500 \AA$

Energy of an electron = E

$E=\frac{hc}{\lambda }$

$E=\frac{6.626\times 10^{-34} Js\times 3\times 10^8 m/s}{500\times 10^{-10}m}$

$E=3.9756\times 10^{-18} J=24.81 eV$

$1 Joule = 6.242\times 10^{18} eV$

It will pass through the potential of 24.81 eV.