Davisson-Germer, Uncertainty, Compton & X-Rays
In an experiment, electrons are made to pass through a narrow slit of width comparable to their de Broglie wavelength. They are detected on a screen at a distance from the slit (see figure).
Which of the following graphs can be expected to represent the number of electrons detected as a function of the detector position corresponds to the middle of the slit
Show answer and solution
Answer: (d)
- Electrons behave as waves and give a single-slit diffraction pattern on the screen.
- This has a broad, tall central maximum at , spreading beyond the slit width , with smaller secondary maxima on both sides.
- Graph (d) shows the central peak plus weaker side peaks; (b) is the shadow of a particle beam and (a), (c) lack secondary maxima.
- So the answer is (d).