Question

The magnification of an electron microscope is much larger than that of an optical microscope, because electron beams are used instead of light beams in an electron microscope.

1. Which property of electrons is used in the construction of the electron microscope?

2. Obtain expression for the wavelength of de Droglie waves associated with an electron accelerated through a potential of V volts.

Answer 1

1. Wave nature.

2. ev = 1/2mv² 

mv² = 2 eV

m²v² = 2eVm

mv = \(\sqrt{2eVm}\)

λ = \(\frac{h}{p}=\frac{h}{\sqrt{2eVm}}\)