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)`.
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Which of the following graphs 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 ).

Options

A.
B.
C.
D.

Answer

D

Explanation

Electron beam serves as a light wave. As width `(d)` of slit is comparable to de-Broglie wavelength, therefore, the electron beam is diffracted on passing through the slit.
We obtain a central maximum surrouded by secondary minima and maxima placed alternately. The intensity is represented by `N` and in diffraction pattern, intensity is never zero. Therefore, choice `(d)` refresents the correct graph, in Fig.