Answer: Intensity (number of photons).
- A Frequency of incident light
- B Square of intensity
- C Intensity (number of photons)
- D Wavelength
Correct answer: C. Intensity (number of photons)
Explanation: Photocurrent proportional to number of emitted electrons proportional to intensity (number of incident photons per second).
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.