Answer: frequency.
- A frequency
- B intensity
- C colour alone
- D phase
Correct answer: A. frequency
Explanation: The maximum kinetic energy, and hence the stopping potential, depends on the light’s frequency.
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.