Answer: E = pc.
- A E = pc
- B E = p/c
- C E = p<sup>2</sup>c
- D E = pc<sup>2</sup>
Correct answer: A. E = pc
Explanation: For a photon, E = hν and p = hν/c, so E = pc.
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.