Answer: small.
- A small
- B large
- C zero
- D infinite
Correct answer: A. small
Explanation: Because λ = h/mv, only very light particles have a measurable wavelength.
In the photoelectric setup, light striking the metal plate ejects electrons that cross the evacuated tube to the collector, producing a measurable current on the ammeter.
Concept context
Photoelectric effect, de Broglie waves, Bohr's model, atomic spectra.