A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct?

Options

A. Diffraction patternn is not observed on the screen in the case of electrons
B. The angular width of the central maxima of the diffraction pattern will increase
C. The angular width of the central maxima will decrease
D. The angularr width of the central maxima will remain the same

Answer

C

Explanation

For electron diffraction, we consider the de broglie waves `(lamda)` associated with them,
`because lamda=(h)/(mv)` then if v is increased, `lamda` will decrease.
the angular width of the central maximum is given by
`2theta=(2lamda)/(a)` where a is the slit width as `theta=lamda`, if `lamda` is decreased, the angular width will also decrease.