Researchers routinely observe clear interference patterns when sending single…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
Researchers routinely observe clear interference patterns when sending single electrons through a narrow double-slit apparatus, yet no comparable pattern is ever recorded when identical equipment is used to launch macroscopic objects such as millimeter-sized glass beads at the same slits.
Answer the following questions in a coherent, well-organized response that references appropriate physical principles.
(a) Describe the essential physical conditions that must be met for an interference pattern to be observable when particles traverse a double-slit apparatus.
(b) Explain qualitatively, without performing any numerical calculation, why electrons readily satisfy these conditions while millimeter-sized glass beads do not.
(c) Discuss how the resolving power of the detection screen and the spatial separation of the slits jointly influence whether any underlying wave character of the incident particles can be detected.
(d) Real laboratory electrons possess a distribution of momenta. Explain how increasing the spread of electron momenta would alter the visibility and sharpness of the interference fringes, and justify your answer.