Answer:
1.94 x 10^-10 m
Explanation:
V = 40 V
The relation for the de broglie wavelength and teh potential difference is given by
[tex]\lambda = \frac{12.27}{\sqrt{V}} Angstrom[/tex]
[tex]\lambda = \frac{12.27}{\sqrt{40}} Angstrom[/tex]
λ = 1.94 Angstrom = 1.94 x 10^-10 m