PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation
Problem
In a Davisson–Germer type setup, electrons accelerated through 54 V give a strong diffraction peak at a glancing angle of about 65°. When the accelerating voltage is raised to 100 V, what qualitative change is expected for the same order peak?
(a) It shifts to a larger angle because the electron wavelength increases.
(b) It remains at the same angle but its intensity increases.
(c) It shifts to a smaller angle because the electron wavelength decreases.
(d) It disappears completely because higher-energy electrons cannot be diffracted.