When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon :-

When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon the frequency of the incident light and the work function of the metal.

1. The first step is to understand the concept of the photoelectric effect. When light, which is made up of photons, falls on a metal surface, it can cause the ejection of electrons from the metal. These ejected electrons are called photo-electrons.

2. The energy of a photon is directly proportional to its frequency. So, the higher the frequency of the incident light, the higher the energy of the photons.

3. The work function of a metal is the minimum amount of energy required to remove an electron from the metal surface. It is a characteristic property of the metal.

4. When a photon with enough energy (greater than or equal to the work function) strikes a metal surface, it can transfer its energy to an electron in the metal. If the energy of the photon is greater than the work function, the excess energy is converted into the kinetic energy of the emitted photo-electron.

5. The maximum kinetic energy of the emitted photo-electrons can be calculated using the equation:

   Kinetic energy = Energy of incident photon - Work function

   This equation shows that the maximum kinetic energy depends on the energy of the incident photon (which is directly related to its frequency) and the work function of the metal.

6. In summary, the maximum kinetic energy of the emitted photo-electrons depends on the frequency of the incident light and the work function of the metal. Higher frequency light and lower work function metals will result in higher maximum kinetic energies.