Question
An electron microscope uses electrons accelerated through 50 kV. Find the deBroglie wavelength of these electrons. If other factors like numerical aperture etc. are roughly the same, how does the resolving power of an electron microscope compare with that of an optical microscope which uses variable light?

None of these



easy
Solution
The deBroglie wave length of Vvolt ‘electron’ is given by
.
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The mean wavelength of visible light may be taken to be , which is 10^{5} times the wavelength of 50kV electrons.
Now, the resolving power of a microscope is inversely proportional to the wavelength of the radiation used. Thus, the resolving power of electron microscope will be 10^{5} times higher than that of optical microscope.
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