What effect does an increase in intensity have according to the photoelectric effect?

In the context of the photoelectric effect, an increase in intensity refers to a greater number of photons hitting the surface of a material. The correct response relates to the outcome of this increased intensity: it affects the emitted photoelectrons by increasing the number of electrons emitted from the material.

When more photons are available (higher intensity), more electrons can absorb the energy required to escape from the surface of the material. However, the energy of each individual photon, which determines how much kinetic energy the emitted photoelectrons will have, does not change with intensity; it is determined by the frequency of the light. Thus, while you may have more electrons being emitted due to increased intensity, the energy of each emitted electron remains constant.

The other options do not accurately describe the effect of increased intensity on the photoelectric effect. Increasing intensity does not reduce photon energy or increase the wavelength of light; both of these attributes are related to the nature of the light source itself rather than the intensity. Furthermore, increased intensity generally leads to a higher current flow due to more emitted electrons, rather than a decrease.