Answer: f₀ = phi/h.
- A f₀ = phi/h
- B f₀ = h/phi
- C f₀ = phi × h
- D f₀ = sqrt(phi/h)
Correct answer: A. f₀ = phi/h
Explanation: Threshold: hf₀ = phi. f₀ = phi/h. Below this frequency, no photoelectrons regardless of 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.