Understanding Magnet Polarity: Magnetic Confusion

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Discussion Overview

The discussion revolves around the confusion regarding the polarity of magnets, specifically in the context of an experiment involving an electromagnet and a permanent magnet. Participants explore the behavior of these magnets under different conditions, including changes in current direction and the influence of the electromagnet's core material.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes an experiment where an electromagnet attracted a permanent magnet regardless of the current direction, leading to confusion about magnet polarity.
  • Another participant suggests that the experimental setup details are crucial for understanding the observed behavior, indicating a possible mistake with polarities.
  • A question is raised about whether the facing side of the permanent magnet remained consistent during the experiment.
  • Details about the electromagnet's construction are provided, including the use of an iron core and insulated copper wire, along with a transformer as the power source.
  • It is noted that when the permanent magnet is turned around, it still attracts the electromagnet, accompanied by increased buzzing, suggesting complex interactions.
  • One participant proposes that rectifying the AC current from the transformer to DC may be necessary to change the current direction effectively.
  • Another participant mentions that the strength of the permanent magnet might be significantly greater than that of the electromagnet, contributing to the attraction observed.
  • There is a suggestion to remove the metal core of the electromagnet, as it could have become permanently magnetized, affecting the results.

Areas of Agreement / Disagreement

Participants express various hypotheses and uncertainties regarding the behavior of the magnets, with no consensus reached on the underlying reasons for the observed attraction or the implications of the electromagnet's construction and power source.

Contextual Notes

Participants note potential limitations in the experimental setup, including the need for clarity on the current type (AC vs. DC) and the strength of the magnets involved, which may influence the outcomes but remain unresolved.

Woodski
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I made myself an electromagnet and did a small experiment involving it and a permanent magnet. When I switched on the electromagnet it attracted the permanent magnet. I made the assumption that they were opposite poles, hence making them attract. However, I changed the current direction of the electromagnet thinking that it would then repel the permanent magnet. However, it also attracted the permanent magent. This has left me highly confused about the polarity of magnets. Can someone please help?
 
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You should give full details of your experimental setup. It sounds as if you made a mistake with your polarities but without seeing the alignments of magnet and coil one can't be sure what's happening.
 
was the permanent magnet's facing side always the same?
 
The electromagnet is made with am iron core with insulated copper wire wrapped around it. The power source is a transformer from my sons train set. When I move the permanent magnet to the top of the electromagnet it is attracted. If I turn the permanent around so the opposite pole is pointing towards the same end of the electromagnet then there is a bit more buzzing by the electromagnet but again the permanent magnet is attracted to it.
 
Woodski said:
The electromagnet is made with am iron core with insulated copper wire wrapped around it. The power source is a transformer from my sons train set. When I move the permanent magnet to the top of the electromagnet it is attracted. If I turn the permanent around so the opposite pole is pointing towards the same end of the electromagnet then there is a bit more buzzing by the electromagnet but again the permanent magnet is attracted to it.

Umm...Seems like you need to rectify the AC current from the transformer to get a DC current to be able to change the current direction through the electromagnet.
 
Yes, make sure you've got DC. Another possibility is that the permanent magnet is magnitudes stronger than the electro-magnet.
 
I believe the transformer is AC-DC. I guess it is just because the magnitudes of the permanent magnet are stronger. However, I would still have thought that they would have repelled because if you have a strong and weak permanent magnet, they will repel. So I am still confused.
 
Try removing the metal core of the electromagnet. It could have become permanently magnetised.
 

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