Strength of a permanent magnet

In summary, permanent magnets have a scalar strength advertised in Teslas, which does not depend on the volume but rather the composition of the magnet. This strength is measured at the surface of the magnet and varies with distance. Coupling two equally-oriented magnets together can approximately double the strength at large distances, but not at short distances. Near the face of the magnet, the field strength may slightly increase or decrease. Stacking two magnets together can also double the field strength at the face, as the flux is channeled in the magnetic material and adds together. Placing disk magnets N to N will double the strength, while placing them N to S will cancel their fields.
  • #1
evouga
10
0
Permanent magnets are advertised as having some scalar strength, say, 1.5 Teslas, depending on the composition of the magnet but not its volume. I'm confused about what this means. Shouldn't the magnitude of the magnetic field vary depending on where you measure it? And if I epoxy together two equally-oriented magnets, I would expect that the magnitude of the magnetic field, at a sufficient distance from the magnets, would be approximately twice the strength of that of one of the magnets alone.
 
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  • #2
Flux density is measured at the surface of the magnet and varies with the distance from the surface. For more info, visit the magnet FAQs at

wondermagnet.com
 
  • #3
Yeah if you coupled two identical Magnets together North to South you would approximately double the strength of the magnet.
 
  • #4
Coupling two magnets together increases the strength at large distances where the magnet looks like a dipole, but not at short distances. Near a face, or at a distance
d<L, there would be little change in the magnetic field. It could be slightly larger or slightly smaller depending on the location.
 
  • #5
The field strength at the face of the magnet does about double by stacking two magnets together. Just did a simple test with some disk magnets I have to confirm this.

The reasons is that the flux will be channeled in the magnetic susceptible material and therefore will add together.
 
  • #6
I thought you were talking about bar magnets. It is correct that disk magnets would add.
But I think they should be placed N to N. Placing them N to S should cancel their fields.
 

1. What is the strength of a permanent magnet?

The strength of a permanent magnet is typically measured in units of Tesla (T) or Gauss (G). It is a measure of the magnetic field that the magnet can produce.

2. How is the strength of a permanent magnet determined?

The strength of a permanent magnet is determined by its magnetic moment, which is a measure of the magnet's overall magnetic strength. This is influenced by factors such as the magnet's size, shape, and the material it is made of.

3. Can the strength of a permanent magnet be changed?

No, the strength of a permanent magnet cannot be changed. It is a characteristic of the material and cannot be altered once the magnet is created. However, the magnetic field can be affected by external factors such as temperature and nearby magnetic fields.

4. What materials are commonly used to make permanent magnets?

The most commonly used materials for making permanent magnets are iron, nickel, and cobalt, as well as their alloys. Other materials such as rare earth metals, including neodymium and samarium, are also used for their strong magnetic properties.

5. How does the strength of a permanent magnet affect its applications?

The strength of a permanent magnet is a crucial factor in its applications. Stronger magnets can be used for lifting heavy objects, powering motors, and generating electricity. Weaker magnets are commonly used in everyday objects such as fridge magnets and compasses.

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