Photoelectric Effect: Max Current, Cutoff Potential, Kinetic Energy

[marshall4]

What is the relationship between the maximum electric current and the intensity of incident light?
-are the inversely proportional?


What colour has the larges cutoff potential?
-is it yellow?

Is cutoff potential effected for violet light?
-no?


How do you calulate maximum kinetic energy of ejected electrons using wavelength?

 

[himanshu121]

Photoelectric equation is

$$eV_0=\frac{hc}{\lambda}-\phi$$

where V0 is cuttoff potential and phi is the work function of the metal

 

[M98Ranger]

The photoelectric effect is a phenomenon in which electrons are emitted from a material when it is exposed to light. The maximum electric current, cutoff potential, and kinetic energy are all important factors in understanding this effect.

The maximum electric current refers to the maximum number of electrons that can be emitted from a material per unit time. It is directly proportional to the intensity of the incident light. This means that as the intensity of the light increases, the maximum electric current also increases. This relationship is described by the equation I ∝ I0, where I is the maximum electric current and I0 is the intensity of the incident light.

The cutoff potential, also known as the stopping potential, is the minimum potential difference needed to stop all emitted electrons from reaching the anode. It is a measure of the energy required to overcome the binding energy of the electrons in the material. The cutoff potential is not affected by the intensity of the incident light, but it does depend on the wavelength of the light. Shorter wavelengths have higher cutoff potentials, as they have more energy to overcome the binding energy of the electrons.

The kinetic energy of the ejected electrons is related to the wavelength of the incident light through the equation Ekin = hν - φ, where h is Planck's constant, ν is the frequency of the light, and φ is the work function of the material. The work function is the minimum energy required to remove an electron from the material. As the wavelength of the incident light decreases, the frequency and energy of the light increase, resulting in higher kinetic energy of the ejected electrons.

The color with the largest cutoff potential would be the color with the shortest wavelength, which is violet. This is due to the higher energy of the shorter wavelength light, which requires a higher cutoff potential to overcome the binding energy of the electrons.

The cutoff potential is not affected by the color of the light, but rather by the wavelength. So, for violet light, the cutoff potential would be higher compared to other colors with longer wavelengths.

To calculate the maximum kinetic energy of ejected electrons using the wavelength, you can use the above equation, Ekin = hν - φ. You would need to know the frequency of the light, which can be calculated using the speed of light (c) and the wavelength (λ) through the equation ν = c/λ. Then, you can substitute the frequency into the equation to calculate the maximum kinetic energy.