In an electron microscope, the resolution that can be achieved is of the order of the wavelength of

Question

In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of $7.5 	imes 10^{-12} \mathrm{~m}$, the minimum electron energy required is close to

Professor PC Thomas Classes · Answer

$\lambda = \frac{h}{\sqrt{2mE}}$. Rearranging for $E$ and substituting $\lambda = 7.5 	imes 10^{-12}$ m gives $\approx 25$ KeV.