Description

Chart Photoelectrical Effects

This is a chart illustrating the photoelectric effect it is designed in a ;

Labeled Diagram

This labeled diagram showcases the key components and the phenomenon of photoelectric effect:

• Light Source :An illustration of a light source emitting photons (light waves) of varying frequencies.
  

  Light source emitting photons
• Metal Plate: A metal plate labeled as “Cathode” which emits electrons when struck by light of sufficient energy.
• Positive Electrode: An electrode placed opposite the metal plate, labeled as “Anode” that attracts the emitted electrons.
• Electric Circuit: A voltmeter or ammeter to measure the current produced by the ejected electrons.

Explanation within the Diagram:

• Arrows depict photons traveling from the light source and striking the metal plate.
• Upon impact with sufficient energy photons, electrons are ejected from the metal plate (photoelectric effect). These ejected electrons are called photoelectrons.
• The minimum energy required to eject an electron from the metal plate is known as the work function ( denoted by the symbol Φ).
• The energy of an individual photon is related to its frequency (f) by Einstein’s equation: E = hf (where E is the energy of the photon, h is Planck’s constant, and f is the frequency of the light).
• If the frequency of the incident light is below the threshold frequency (f0) required to overcome the work function, no electrons are ejected (no matter the intensity of the light).
• If the frequency of the incident light is above the threshold frequency, electrons are ejected with kinetic energy (KE) equal to the difference between the photon energy (hf) and the work function (Φ) : KE = hf – Φ. This explains why higher frequency light (even with lower intensity) can eject electrons with higher kinetic energy.