Electrostatics lab report question

[Cheim2003]

Hi everyone, I was wondering if anyone could give me any input on this question over an electrostatics lab I recently did. The part I'm not sure about was a section where we sampled the charges of several different wands by placing them into a Faraday ice pail connected to an electrometer. The first portion of it were were to rub two wands together (that we had grounded to remove any charge) and then insert them individually into the ice pail to measure the magnitude and polarity of the charge on each one. The second part was to ground each wand, then insert them into the pail together, then to rub them together and sample the charge by removing each one. Now, when I did this I didn't notice a difference in magnitude or polarity of charge on either wand using the two techniques. However, the way the question in my lab is worded leads me to believe that I should have. Anyone wish to weigh in?

Thanks, Chris

 

[anathema]

Hi Chris,

First of all, great job on completing the electrostatics lab and being curious about your results! It sounds like you did the experiment correctly, but there may be a few factors that could explain why you didn't notice a difference in magnitude or polarity of charge using the two techniques.

One possibility is that the wands you used may not have had a significant amount of charge to begin with. Even though you grounded them before the experiment, there may still have been some residual charge that was not completely removed. This could have resulted in similar readings for both techniques.

Another factor to consider is the sensitivity of the equipment you used. The electrometer may not be able to detect small differences in charge, especially if the wands were not highly charged to begin with. In this case, you may not have noticed a difference in the readings.

It's also important to note that the rubbing technique may not always result in a significant transfer of charge between the wands. This could be due to various factors such as the materials of the wands, the amount of pressure applied during rubbing, or even humidity in the air. All of these can affect the transfer of charge and may have played a role in your experiment.

Overall, I would recommend repeating the experiment with different wands and possibly using a more sensitive electrometer to see if you can detect any differences in charge using the two techniques. It's also worth discussing your results with your lab instructor or classmates to see if they had similar observations.

I hope this helps and good luck with your future experiments!

 

[quicknote]

Sure, I will be happy to provide some input on your question. From the description of your experiment, it seems that you were trying to compare the charge on the wands when they were rubbed together while grounded versus when they were not grounded. In theory, grounding the wands should remove any excess charge on them, resulting in a smaller or no difference in charge when compared to the ungrounded wands. However, in practice, there may be some residual charge left on the wands even after grounding, which could explain why you did not notice a difference in magnitude or polarity of charge.

To further investigate this, you can repeat the experiment multiple times and take multiple readings to see if there is any consistency in the results. You can also try using different types of wands or different materials to see if that affects the charge readings. Additionally, you can try using a more sensitive instrument to measure the charge, as the electrometer may not be able to detect small differences in charge.

Overall, it is important to carefully follow the instructions of the experiment and make sure all variables are controlled to get accurate results. If you are still unsure about your results, it would be best to consult with your instructor or a fellow classmate to discuss and compare your findings.