Which of the following is true of the photoelectric effect?
A) The number of electrons emitted by a metallic surface is independent of the frequency of incident light.
B) The number of electrons emitted by a metallic surface is independent of the intensity of light at any frequency.
C) The number of electrons emitted by a metallic surface is directly proportional to the intensity of incident light above the threshold frequency.
D) The number of electrons emitted by a metallic surface is proportional to the frequency of incident light only below a certain light intensity.
E) The number of electrons emitted by a metallic surface is inversely proportional to the intensity and frequency of incident light.

Question

Quizplus · Accepted Answer

The photoelectric effect states that the number of electrons emitted by a metallic surface is directly proportional to the intensity of incident light above the threshold frequency. This means that higher intensity leads to more electrons being emitted, but only if the frequency is high enough to overcome the material's work function. The number of electrons emitted also depends on the frequency of the incident light, but this is only relevant below a certain light intensity (the threshold intensity) where the number of electrons emitted does not increase even if the frequency increases. The choice that best describes the photoelectric effect is C.

Which of the Following Is True of the Photoelectric Effect