Paragraph: Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see in figure).
Question: In an experiment, electrons are made to pass through a narrow slit of width '$$d$$' comparable to their de Broglie wavelength. They are detected on a screen at a distance '$$D$$' from the slit (see figure).
Which of the following graph can be expected to represent the number of electrons '$$N$$' detected as a function of the detector position '$$y$$' ($$y = 0$$ corresponds to the middle of the slit)?