question_answer

The speed of electrons in an electron microscope is\[\mathbf{1}{{\mathbf{0}}^{\mathbf{8}}}\mathbf{m}{{\mathbf{s}}^{\mathbf{-1}}}\]. If protons with the same speed are used instead of electrons, what additional advantage such a proton microscope has over an electron microscope?

Answer:

                                                                de -Broglie wavelength, \[\lambda =\frac{h}{m\upsilon }\] As the mass of a proton is 1836 times that of an electron, so for the same speed, the wavelength of proton beam will be\[\frac{1}{1836}\]times that of an electron beam. But resolving power of a microscope \[\propto \frac{1}{\text{wavelength}}.\] Hence the resolving power of a proton microscope will be 1836 times that of an electron microscope.