Answer: Stop all emitted electrons.
- A Accelerate electrons
- B Stop all emitted electrons
- C Increase photo current
- D Change threshold frequency
Correct answer: B. Stop all emitted electrons
Explanation: Stopping potential V<sub>0</sub> halts all emitted electrons. eV<sub>0</sub> = maximum KE of emitted electrons = hf - phi.
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.