Comparing Lab Results to Theory: Equipotential Lines Analysis

In summary, the conversation discusses a lab where the result is significantly different from the theoretical value. The lab involves using a sheet of conductive paper with dipole electrodes connected to a battery and voltmeter to measure voltage on different points. The result shows all positive numbers, while the theory predicts only half of the equipotential lines to be positive. Possible explanations for this discrepancy include the battery not being powerful enough or the conductive paper not being thick enough. The speaker seeks guidance from their professor or TA to understand and solve the problem.
  • #1
cy19861126
69
0
Okay, we are supposed to do a lab in class and compare it to the real results. However, for some reason, my lab result is very different from my theoretical value.

The lab is like this: I put a sheet of conductive paper with the dipole electrodes, one positive and one negative, of course. I connected the two electrodes to a battery by clip-leads. Also, I connected the Voltmeter to the two pins on the electrodes, I connected one of the wires from Voltmeter to the negative electrodes and one another (positive) to various places on the conductive sheet. In the lab, the two electrodes are points. Therefore, this is a situation of two point charges.

After I placed the positive probes on various places and measured the voltage on a 0.5V increments, I drew the lab result. The shape of the result is fine; it is almost exactly like what you would fine on a topography, but what I'm concerned about are the numbers. The voltage numbers all came out to be positive, while from the theory, only half of the equipotential lines are positive (the half that is close to the positve side).

If you want to know what the theory would look like, you can go to: http://www.colorado.edu/physics/phet/simulations/chargesandfields/ChargesAndFields.swf. The way to use this is to drag 1nC to the top of the page and -1nC to the bottom of the page. And on the lower left hand corner, try and plot different equipotential lines. Remember to click on "show numbers" on the lower right hand corner
 
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  • #2
before plotting the lines. There could be a couple of factors that could explain why this might be the case. The first could be that the battery I used in the lab wasn't powerful enough to create a larger potential difference, thus the numbers all appeared to be positive. The second is that the conductive paper I used in the lab wasn't thick enough, or it wasn't made out of material that allows for a large potential difference. It would be helpful to have some guidance from my professor or TA in order to understand why this discrepancy is happening and what I can do to solve the problem.
 
  • #3
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As a scientist, it is important to carefully analyze and compare experimental results to theoretical values. In this case, it seems that your lab results are significantly different from the expected theoretical values. This could be due to a number of factors such as experimental error, equipment malfunction, or even incorrect set-up of the experiment. It is important to carefully review your experimental procedure and data to identify any potential sources of error.

Additionally, it is important to keep in mind that theoretical values are based on ideal conditions and may not always match up exactly with experimental results. This is why it is important to repeat experiments multiple times and take an average to get a more accurate representation of the data.

In this specific experiment, it may also be helpful to compare your results with those of your classmates to see if there are any discrepancies and to discuss potential sources of error. It may also be beneficial to consult with your instructor or a teaching assistant for further guidance.

Overall, it is important to carefully analyze and interpret experimental results, and to always consider potential sources of error when comparing them to theoretical values.
 

Related to Comparing Lab Results to Theory: Equipotential Lines Analysis

1. What is the purpose of comparing lab results to theory using equipotential lines analysis?

The purpose of this comparison is to determine the accuracy and validity of the theory by comparing the predicted results with the actual results obtained from the lab experiment. This analysis helps to identify any discrepancies and assess the overall performance of the theory.

2. How are equipotential lines used in this analysis?

Equipotential lines are imaginary lines drawn in a two-dimensional graph that connect points with equal potential energy. In this analysis, these lines are used to visually compare the predicted and actual results. If the lines overlap or are very close to each other, it indicates a good fit between the theory and experiment. However, if there are significant differences between the lines, it suggests that the theory may need to be revised.

3. What factors can affect the accuracy of the comparison between lab results and theory?

There are several factors that can impact the accuracy of this comparison, such as experimental errors, limitations of the theory, and external factors like environmental conditions. It is important to carefully control and account for these factors to ensure a more accurate comparison.

4. What are some limitations of using equipotential lines in this analysis?

One limitation is that this method only works for two-dimensional systems, so it may not be applicable to all experiments. Additionally, it assumes that the potential energy remains constant along the equipotential lines, which may not always be the case. Other factors such as boundary conditions and non-uniform electric fields can also affect the accuracy of the analysis.

5. How can the results of this analysis be used to improve the theory?

If there are significant discrepancies between the predicted and actual results, it suggests that the theory may need to be revised or improved. By identifying these discrepancies and analyzing the possible sources of error, scientists can make adjustments to the theory to better fit the experimental data. This can lead to a more accurate and reliable understanding of the phenomenon being studied.

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