Question

Electrons are accelerated by a potential difference of 100v and 400v.

Calculate the wavelength associated with the electrons in each case

Answer 1

a)

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

$$\lambda_1=\frac{hc}{eV_1}=\frac{1239.84}{100}=12.4\ nm$$

b)

$$\lambda_2=\frac{hc}{eV_2}=\frac{1239.84}{400}=3.1\ nm$$