A beam of electrons, each with the same kinetic energy, illuminates a pair of slits separated by a distance of 65 nm. The beam forms bright and dark fringes on a screen located a distance 2 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 0.2 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.

Ek=142.7keV

Explanation:

First we have to compute the associated wavelength of the electrons by using the formula for the interference condition:

where m is the order of the fringe, lambda is the wavelength of the electrons, d is the distance between the slits and D IS the distance to the screen. By taking m=1, we have that the distance between the first fringes is 0.2mm. Hence, from the middle of the screen we have that y=0.1mm=0.1*10^{-3}m.

By replacing we have:

Now, by using the Broglie's relation we get:

hope this helps!!

explanation:

a fuel engine ( known as a gasoline engine in american english )is an internal combustion engine with spark ignition, designed to run on petrol (gasoline) and similar volatile fuels.

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.