Question

What is meant by the Photoelectric effect?

Answer 1

Hint: By explaining the phenomenon of metals releasing electrons, when they are exposed to the light of the appropriate frequency is called the photoelectric effect. The electrons that are emitted during the process are called photoelectrons where the incident light should have energy more than the work function of the surface.

Complete Step By Step Answer:
The photoelectric effect means the ejection of electrons from the surface of a metal when an incident light falls on it. This takes place because of the energy of incident photons of light that have more energy than the work potential of the incident metal surface, emitting electrons with positive kinetic energy.
Where Photon energy is given by $ \left( {E = hf{\text{ }}or{\text{ }}E = \dfrac{{hc}}{\lambda }} \right). $ where $ h $ is Planck’s constant, $ f $ is the frequency of incident light, $ \lambda $ = wavelength of the incident light, $ c $ is the speed of light in a vacuum
This ejection of the electron process is generally known as photoemission. The work function is known as the minimum energy needed by a conduction electron to escape from the metal surface when the metal is at zero potential. If the conduction electron doesn’t leave the metal, it collides with other electrons repeatedly and positive ions and loses its excessive kinetic energy and the frequency should be above the threshold irrespective of the intensity of incident light. This is the whole phenomenon of the photoelectric effect.

Note:
The photoelectric effect happens because the electrons at the surface of the metal tend to capture energy from the incident light and use it to overcome the attractive forces that bind them to the metallic nuclei. This energy will be more than the work potential of the incident surface. The obtained energy is represented in the above equation for a given frequency and wavelength of incident light.