CBSE Class 12 · 2014 · Modern PhysicsShort Answer

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An electron microscope uses electrons accelerated by a voltage of 50 kV. Determine the de-Broglie wavelength associated with the electrons. Taking other factors, such as numerical aperture etc., to be the same, how does the resolving power of an electron microscope compare with that of an optical microscope which uses yellow light?

Answer: ; resolving power times the optical microscope.

Solution

De-Broglie wavelength:

Resolving power . Yellow light has , so the electron wavelength is smaller by a factor .
Hence the electron microscope has a resolving power about times that of the optical microscope.

CBSE Class 12 Board · 2014 · Subjective

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