Creating a Magnetic Quadrupole w/Earth Magnets

  • Context: Undergrad 
  • Thread starter Thread starter caters
  • Start date Start date
  • Tags Tags
    Magnetic
Click For Summary

Discussion Overview

The discussion revolves around the creation of a magnetic quadrupole using Earth magnets, focusing on the stability of the arrangement and the challenges faced in maintaining the configuration in open space.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant describes their attempt to create a magnetic quadrupole with Earth magnets, noting the intended attraction and repulsion between the magnets.
  • Another participant questions the assumption that the quadrupole arrangement is stable on its own, suggesting that it may not be.
  • A different participant asserts that the arrangement represents an unstable equilibrium, where perfect positioning results in no net forces, but any slight deviation leads to collapse.

Areas of Agreement / Disagreement

Participants express differing views on the stability of the magnetic quadrupole arrangement, with some suggesting it is inherently unstable while others seem to assume it should be stable in open space.

Contextual Notes

The discussion does not resolve the assumptions about the stability of the quadrupole arrangement or the conditions required for maintaining it in open space.

caters
Messages
229
Reaction score
10
I have heard of a magnetic quadrupole. It is often represented as 4 bar magnets separated and arranged in such a way that for any 1 magnet it is attracted to the magnets 90 degrees from it but is repelled by the magnet 180 degrees from it. I have tried to form it with Earth magnets thinking that the stronger the magnet the more likely it is to form a quadrupole. But I have had no success. I successfully get the 4 magnets separated and at angles of 180 and 90 degrees making sure that the ones at 180 degrees repel and the ones at 90 degrees attract.

However the problem comes when I get rid of what is separating the magnets. Either 1 of the magnets turns 180 degrees or it flips or it turns 90 degrees. Either way pairs of magnets attach themselves.

How can I have magnets in open space form a quadrupole?
 
Physics news on Phys.org
Why do you assume the quadrupole arrangement is stable on its own? I'm pretty sure it isn't.
 
I assume that because I have always seen it represented as 4 magnets in open space.
 
I think the arrangement is a classic example of an unstable equilibrium. In perfect positions there are no net forces, but even the slightest deviation will make it collapse.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
10K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
13K
  • · Replies 2 ·
Replies
2
Views
1K