Magnetic field of magnet and its defination

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Discussion Overview

The discussion revolves around the definition and representation of magnetic fields associated with magnets, particularly focusing on how to accurately draw magnetic field lines. Participants explore the implications of defining magnetic poles and the challenges of visualizing magnetic fields in different orientations.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about how to draw magnetic field diagrams, noting that the traditional representation of field lines emerging from the north pole may not accurately reflect the nature of magnetic fields as constant loops.
  • Another participant shares a perspective that field lines are not particularly useful, suggesting that the focus should be on the interaction between a magnet and nearby materials, such as iron, which can induce opposite poles.
  • A later reply reiterates the previous point about the unpredictability of field lines and suggests a method of drawing induced poles when both poles of a magnet are exposed to a piece of iron.
  • Participants share a common sentiment of frustration regarding the complexity of field lines and their representation.

Areas of Agreement / Disagreement

Participants generally express a shared frustration with the concept of field lines, but there is no consensus on the best method for drawing them or the implications of defining magnetic poles. Multiple competing views on how to visualize magnetic fields remain present.

Contextual Notes

The discussion highlights limitations in the understanding of magnetic field representations, including the dependence on definitions of magnetic poles and the challenges of accurately depicting fields in various scenarios.

Who May Find This Useful

This discussion may be useful for individuals interested in physics, particularly those exploring concepts related to magnetism and magnetic fields, as well as educators seeking to understand common misconceptions among students.

sgstudent
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When we consider a magnet, usually we perceive the field lines to come out of the north pole. But since the poles of a magnet is actually just a man-defined thing, so actually the magnetic field doesn't emerge from the north but it's a constant loop. So when i draw the magnetic field of a bar magnet in this position, instinctively i will draw it like this: http://postimage.org/image/yzybv7vrl/full/

However if i invert my magnet then i would draw it like this:http://postimage.org/image/sh5ksynwt/full/

So if i take the north pole to be where the magnetic field emerges from, then the two magnetic field diagrams would be different but in actuality the second image should look similar to the first.

Thus, from this I'm confused about how i should draw my magnetic field diagram. Are there any guidelines so that i will draw the correct ones? Thanks for the help!
 
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I hate field lines too - fortunately they're not a very useful thing and you rarely see them being used except as a general indication of a field.

Anyway, the best way to look at is: If you bring a piece of iron near a pole, the pole will induce an opposite pole in the iron nearby. (it doesn't matter if it's a north or south pole)
Then that pole will induce another opposite pole in the iron as far away as it can. If it's a funny shape, it will induce several poles at the farthest points.

Once you've located all the induced poles, you can draw the field lines between them and add in any curves you feel might make it look more smooth.
 
AJ Bentley said:
I hate field lines too - fortunately they're not a very useful thing and you rarely see them being used except as a general indication of a field.

Anyway, the best way to look at is: If you bring a piece of iron near a pole, the pole will induce an opposite pole in the iron nearby. (it doesn't matter if it's a north or south pole)
Then that pole will induce another opposite pole in the iron as far away as it can. If it's a funny shape, it will induce several poles at the farthest points.

Once you've located all the induced poles, you can draw the field lines between them and add in any curves you feel might make it look more smooth.

Haha :smile: we share the same pain. Field lines are so unpredictable. Your method really great! Thanks!
 
AJ Bentley said:
I hate field lines too - fortunately they're not a very useful thing and you rarely see them being used except as a general indication of a field.

Anyway, the best way to look at is: If you bring a piece of iron near a pole, the pole will induce an opposite pole in the iron nearby. (it doesn't matter if it's a north or south pole)
Then that pole will induce another opposite pole in the iron as far away as it can. If it's a funny shape, it will induce several poles at the farthest points.

Once you've located all the induced poles, you can draw the field lines between them and add in any curves you feel might make it look more smooth.

Hello again. I was thinking about this and i thought what if both of the poles are exposed to the iron bar like this. Then how should i approach it? Should i draw both induced poles and from there draw the magnetic field? Something like this: http://postimage.org/image/5n2feusjf/full/

Thanks for the help!
 
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