AN electron beam can undergo diffraction by crystals . through wat potential should beam of electrons be accelerated so that its wavelength becomes equal to 1.54 Armstrong.???

Question

anonymous · Answer

Angstrom, not Armstrong (I made the same mistake at first).
$$1.54Å=1.54*10^{-10}m$$$$E_{(eV)}=eV=hc/\lambda$$
In any case, I get a potential of about 8,051 volts.$$V=hc/e\lambda=(6.63*10^{-34}*3.00*10^8Jm)/(1.60*10^{-19}*1.54*10^{-10}Cm)$$$$V=8.05*10^3J/C=8.05*10^3V$$