Question

A beam of electrons, each with the same kinetic energy, illuminates a pair of slits separated by a distance of 56 nm. The beam forms bright and dark fringes on a screen located a distance 1 m beyond the two slits. The arrangement is otherwise identical to that used in the optical two-slit interference experiment. The bright fringes are found to be separated by a distance of 0.6 mm. What is the kinetic energy of the electrons in the beam? Planck’s constant is 6.63 × 10−34 J · s. Answer in units of keV.

Answer 1