Questioning photoelectric effect theory

In summary, the conversation discusses an experiment involving the use of LEDs of different wavelengths to record photocurrent created by striking a metal. The data was used to find an equation relating the wavelength of the incident light to the current produced. However, when the experiment was repeated with different light sources, the retarding potentials did not fit with the data from the LEDs. The photoelectric effect states that only the frequency of the incident light matters, but the current is affected by its intensity. The participant asks if there are any other factors that could affect the current produced through the photoelectric effect besides frequency. The difference in frequency and intensity of different light sources can result in varying amounts of current produced.
  • #1
moonman
21
0
I'm working on a lab where I used LEDs of different wavelenths to record photocurrent they create when striking a metal. Using this data, i was able to find an equation relating the wavelength of the incident light to the current that is produced.
My problem is that when I repeated the experiment with different light sources (HeNe Laser, Hg lamp), the retarding potentials did not fit with the data from the LED's. The photoelectric effect says that the only thing that matters in the incident light is its frequency, because things like intensity are irrelevant. So I don't see why different light sources should create different currents. I don't know if what I said made any sense, but can anyone help me out here? Basically I'm asking if there are any other factors that would effect the current produced through the photoelectric effect other than frequency. I hope someone out there can help me out. thanks
 
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  • #2
moonman said:
The photoelectric effect says that the only thing that matters in the incident light is its frequency, because things like intensity are irrelevant.
Right and wrong.. the retarded potential is related to its frequency only, but the current is affected by its intensity,

moonman said:
My problem is that when I repeated the experiment with different light sources (HeNe Laser, Hg lamp), the retarding potentials did not fit with the data from the LED's.
different light sources has different frequence.. for example.. a red light has a lower frequence than a blue light.. surely you won't get a same result using different light source..

moonman said:
So I don't see why different light sources should create different currents
different light source not only have different frequency (color), their intensity (strength) varies, too..
 
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  • #3


The photoelectric effect theory is a fundamental concept in physics that explains how light can cause the emission of electrons from a metal surface. It states that the energy of the incident light (determined by its frequency) is responsible for the energy of the emitted electrons, while the intensity of the light does not affect this process.

Based on your experiment, it seems that you have found an equation relating the wavelength of the incident light to the current produced in the photoelectric effect. However, you have noticed that this equation does not hold true for all light sources, as the retarding potentials did not fit with the data from the LED's when using different light sources like a HeNe laser or Hg lamp.

This discrepancy raises an important question about the photoelectric effect theory. Are there other factors that could affect the current produced in the photoelectric effect, besides the frequency of the incident light?

One possible explanation for this inconsistency could be the different intensities of the light sources. While the photoelectric effect theory states that the intensity of the light does not affect the energy of the emitted electrons, it could still affect the number of electrons that are emitted. Therefore, it is possible that the different light sources used in your experiment had varying intensities, leading to different currents being produced.

Another factor that could potentially affect the current in the photoelectric effect is the surface properties of the metal being used. Different metals have different work functions, which is the minimum energy required to remove an electron from the surface of the metal. This could also contribute to the varying currents observed in your experiment.

In conclusion, while the photoelectric effect theory is a well-established concept, there may be other factors at play that could affect the current produced in the photoelectric effect. Further experimentation and analysis may be needed to fully understand the discrepancy you have observed in your experiment.
 

Related to Questioning photoelectric effect theory

1. What is the photoelectric effect theory?

The photoelectric effect theory is a scientific explanation for how light can cause the emission of electrons from a material. It states that when light of a certain frequency, called the threshold frequency, shines on a metal surface, it can transfer enough energy to the electrons in the metal to overcome the attractive forces holding them in place and cause them to be emitted.

2. What evidence supports the photoelectric effect theory?

There have been numerous experiments conducted over the years that support the photoelectric effect theory. One of the most well-known is the work of Albert Einstein, who used the theory to explain the results of the photoelectric effect experiments. Additionally, the theory has been confirmed through the observation of the photoelectric effect in a variety of different materials and under different conditions.

3. Is the photoelectric effect theory universally accepted?

While the photoelectric effect theory is widely accepted in the scientific community, there are still some ongoing debates and discussions about certain aspects of the theory. However, the majority of evidence and research supports the theory and it is considered a fundamental concept in the field of physics.

4. How does the photoelectric effect theory relate to quantum mechanics?

The photoelectric effect theory played a crucial role in the development of quantum mechanics. The theory introduced the idea that light could act as both a wave and a particle, which was a key concept in the development of quantum mechanics. The theory also helped to explain the discreteness of energy levels in atoms, which is a fundamental principle in quantum mechanics.

5. Can the photoelectric effect theory be applied to other phenomena?

While the photoelectric effect theory was initially developed to explain the emission of electrons from metals, it has since been applied to other phenomena, such as the emission of electrons from semiconductors and the behavior of photons in photosynthesis. Additionally, the principles of the theory have been extended to other areas of physics, such as the study of the interaction between light and matter.

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