Do fields created by magnets add up?

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Discussion Overview

The discussion centers on the behavior of magnetic fields created by stacked magnets, specifically whether the strength of the magnetic field measured by a gaussmeter would double when two identical magnets are stacked. Participants explore the principles of superposition and vector addition in magnetic fields, as well as practical implications related to magnet specifications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if the magnetic field strength would read double when stacking two identical magnets, suggesting that distance between the magnets may affect the measurement.
  • Another participant proposes that magnetic fields obey superposition, indicating that if the current is doubled, the magnetic field would also double.
  • Some participants assert that electromagnetic fields do stack and add linearly, while others caution that the fields from two magnets can cancel each other at certain points due to vector addition.
  • A participant mentions that stacking magnets of different thicknesses could yield a stronger field than a single thicker magnet, depending on the materials and configurations used.
  • There is a discussion about the properties of rare earth magnets and their applications in miniaturized electronics, though this is somewhat tangential to the main question.
  • One participant clarifies that if two magnetic fields are aligned in the same direction, they add up, while opposing fields would result in a different net strength.

Areas of Agreement / Disagreement

Participants express differing views on whether the magnetic fields from stacked magnets add up linearly and how vector addition affects the overall strength. There is no consensus on the exact behavior of the fields when magnets are stacked.

Contextual Notes

Participants mention various assumptions regarding the alignment and materials of the magnets, as well as the influence of distance on field strength, which remain unresolved.

SMD1990
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If I were to use a gaussmeter to measure the strength of a magnet's magnetic field, would the value read be double if I were to stack two (of the same kind of magnets) on top of one another?
 
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I THINK it might, but I'm not entirely sure. If you're thinking exactly double, probably not, since there is still a difference between the two magnets positions so one spot is technically further. But I think it should be double for the most part.
 
Well B fields obey superposition. And if we think of amperes law and if i were to double the current enclosed then the B field would double.
 
Yes, electromagnetic fields obey superposition and will stack as you guessed.
 
Why I was wondering is, I was looking at Magcraft's selection of magnets. Taking into account the differences in thickness, http://www.rare-earth-magnets.com/p-5-nsn0592.aspx" of theirs are the strongest.

So if you were to stack them, and their magnetic fields add-up linearly, then they are stronger than individual singular magnets of a greater thickness.
 
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Those itty bitty super magnets are probably made with rare Earth materials. Apparently they channel or enhance the magnetic properties of materials or something. I'm not sure why, but I think that's what the article said. They play a major role in allowing us to have miniaturized electronics, so we don't need earbuds the size of an egg or something.

I saw a picture of one holding a foot long wrench in a National Geographic magazine, and it was maybe half a centimeter long(if i had to guess). It looked like a cylinder, for the most part, but angled, so like a hexagon with depth.
 
SMD1990 said:
Why I was wondering is, I was looking at Magcraft's selection of magnets. Taking into account the differences in thickness, http://www.rare-earth-magnets.com/p-5-nsn0592.aspx" of theirs are the strongest.

So if you were to stack them, and their magnetic fields add-up linearly, then they are stronger than individual singular magnets of a greater thickness.
Magnetic fields from two sources add up as vectors at each point. So the strength of the field is not necessarily the sum of the strengths. In extreme case, the fields from two magnets can cancel at certain points.

Assuming same materials and cross-section of bar or cylinder magnets, two magnets of length L/2 stacked together should give you the same field as single magnet of length L.
 
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If they go in the same direction the add up. 5Tesla up + 10 Tesla up = 15 Tesla. 10 Tesla up + 5 Tesla down= 5 Tesla. Its all vectors.
 

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