Question

Why does the amount of photoelectrons ejected increase linearly with illumination time?

Answer 1

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.