Why does the amount of photoelectrons ejected increase linearly with illumination time?
The amount of photoelectrons ejected from a metal surface is directly proportional to the intensity (brightness) of the incident light and the time it is illuminated. As the incident light shines on the metal surface, more and more electrons are excited and ejected from the surface. The number of electrons ejected is proportional to the number of photons that hit the surface, which is proportional to the intensity of the light and the time it is illuminated. Therefore, the amount of photoelectrons ejected increases linearly with illumination time.
The amount of photoelectrons ejected increasing linearly with illumination time can be explained by the basics of the photoelectric effect. Here are the steps:
1. The photoelectric effect occurs when light, typically in the form of photons, is incident on a material surface.
2. When the photons hit the surface of a material, they transfer their energy to the electrons within the material.
3. In order for electrons to be ejected from the material, the energy of the incident photons must be greater than the work function of the material. The work function is the minimum energy required to remove an electron from the material's surface.
4. If the incident photons have sufficient energy, they can overcome the work function, freeing the electrons from the surface of the material. These freed electrons are referred to as photoelectrons.
5. The number of photoelectrons ejected from the material depends on the number of incident photons and their energy. When the illumination time increases, the number of incident photons hitting the material surface also increases.
6. Since each incident photon can potentially eject an electron, an increase in the number of incident photons will result in a linear increase in the number of ejected photoelectrons.
Therefore, the amount of photoelectrons ejected increases linearly with illumination time because more incident photons are available to transfer their energy and free electrons from the material surface.