In the photoelectric effect, increasing the intensity of the incident light while keeping the frequency fixed increases
Correct answer: B. the number of electrons emitted per second
- A. the maximum kinetic energy of the emitted electrons
- B. the number of electrons emitted per second
- C. the threshold frequency
- D. the work function of the metal
Explanation
More intense light means more photons per second, so more electrons are ejected, but each photon still carries the same energy hf and so gives each electron the same maximum kinetic energy. Only raising the frequency raises that energy. The failure of the wave theory to predict this is the strongest evidence for the particle nature of light.
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About Photons and the Particle Model of Light
The particle model treats light as photons with energy E equals hf and momentum related to wavelength. Questions involve the photoelectric effect, work function, threshold frequency, stopping potential and photon energy, while distinguishing particle behaviour from the wave description of interference and diffraction.
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