The photoelectric effect is an important subject matter in the study of light. The photoelectric effect is a phenomenon where electrons are dispelled from the surface of the metal on which a ray of light strikes under certain suitable circumstances. This phenomenon and its study by Einstein helped dispel some of the debates that surrounded the behaviour of light. The light had dual properties of wave-like formations and particle-like formations that were packed closely. The particle of light was called photons. It is on this photoemission that photoelectric equations are based. Kinetic energy is required to dispel the electrons, as well as the photoelectrons themselves, which have a certain kinetic energy that is related to the intensity of the light. 

Different Graphs

In the study of the photoelectric effect, different graphs can be produced depending on variations in the intensity and kinetic energy involved in the Photoelectric Effect. The equation is KEmax = hv – . The line equation is y = mx + c. So, m is h and c is – . From there it was proven that the slope is dependent on Planck’s constant but is not dependent on radiation intensity. However, the point where the line is drawn in the negative values on the Y-axis represented by c is dependent on the work function . The different types of graphs are:

• • Photoelectric current vs Retarding Potential
  • Saturated Current vs Intensity
  • Vmax V/sV
  • Potential vs Current
  • Stopping potential vs Frequency

• Kinetic Energy vs Frequency

Kinetic Energy

Kinetic Energy is defined as the energy that a particle has due to its motion. It is further defined as the work required to accelerate the body or particle into motion from rest. It is this acceleration that helps the object or article attain motion and creates kinetic energy. Kinetic Energy in the photoelectric effect refers to the energy produced during the emission of electrons or photoelectrons from the surface of a metal when light hits the surface with enough intensity or has a shorter wavelength and the threshold frequency is surpassed. The photoelectric current is directly proportional to the frequency of light. 

Kinetic Energy Graph

The Kinetic Energy Graph when plotted onto a graph shows the given results:

• The kinetic energy is represented by a line and for a body in motion, the line will be straight
• The formula is K = ½ mv2, where K is kinetic energy, m is the mass and v is the velocity
• Kinetic energy for a body in motion will be directly proportional to the velocity square.
• The slope indicated that it is not constant

Kinetic Energy vs Frequency

The kinetic energy vs frequency graph has the following elements:

• The vertical axis is the energy
• Horizontal axis is the frequency
• Positive values indicate the kinetic energy of electrons
• Negative values indicate the lack of energy needed for electrons to break free
• X intercept represents the threshold frequency
• Y-intercept represents the material’s work function
• KE = hv – , the line equation is y = mx + c. So, m is h and c is – .

Conclusion

The amplitude of light influences the photons in the light. The higher the amplitude, the more photons will be hitting the metal body and upon crossing the threshold frequency, will expel photoelectrons. So, the light frequency must be higher than the threshold frequency. Therefore, it is demonstrable through plotting it on a graph, that the ejection of electrons is directly proportional to the increase in amplitude.