An electron beam can undergo defraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes `1.54` Å?

An electron beam can undergo defraction by crystals. Through what pote

1.	An electron beam can undergo defraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes `1.54` Å?
Answer» Correct Answer - C For `1.54 Å` wavelength, the momentum for electron would be given by the expression `p = (h)/(lambda) rArr v = (h)/(m lambda)` The potential to which a beam of electron be acceletated is given by the expression `eV = (1)/(mv^(2))` `i.e. V = (1)/(2me) ((h)/(lambda))^(2)` Substituting the value , we get `V = (1)/((2)(9.1 xx 10^(-31)kg) (1.6 xx 10^(-19)C))((6.626 xx 10^(-34) J s)/(1.54 xx 10^(-10)m))^(2)` `= 63.573 m s^(-1)`

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An electron beam can undergo defraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes `1.54` Å?

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