Answer: All of above.
- A No photons are emitted
- B Electron emission does not occur
- C Maximum KE is zero
- D All of above
Correct answer: D. All of above
Explanation: Below threshold frequency: E = hf < phi. No electrons are emitted regardless of 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.