Answer: intensity.
- A intensity
- B frequency
- C wavelength
- D phase
Correct answer: A. intensity
Explanation: The number of photoelectrons, and hence the current, is proportional to the light intensity.
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.