How to predict a magnet's field strength?

In summary, the conversation discusses the process of creating permanent magnets by exposing ferrous material to an electromagnet. The speaker is interested in finding formulas or rules of thumb to estimate the resulting field strength of the magnet. They also mention the importance of the strength of the magnetic field and the time the material is exposed, as well as the potential effect of material qualities. The conversation also references a method of using an electromagnet and lowering the temperature to create a permanent magnet.
  • #1
downtownjapan
6
0
Hi,

I am interested in making my own (weak) magnets exposing some ferrous metal to the magnetic field of an electromagnet, but this is theoretical rather than something I am able to actually do right now. I am wondering if there are any formulas that can help calculate/estimate the resulting field strength of the permanent magnet being created. I am guessing the key factors are the strength of the field the ferrous material is exposed to, and the time the material is exposed - but I am not sure how the material qualities might affect the process. Are there any formulas or even rules of thumb that I can use to estimate the permanent magnet's field strength?

Thanks,
Eddie
 
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  • #2
Are you planning something like this guy does?

http://www.instructables.com/id/Permanent-Magnets/

If you heat a magnetic material above its "Curie temperature" it will lose any existing magnetization. So when it is in this condition you can expose it to a strong magnetic field (e.g., via an electromagnet such as a Helmholtz coil), and slowly lower the temperature.

See http://en.wikipedia.org/wiki/Curie_temperature
and http://en.wikipedia.org/wiki/Helmholtz_coil

You can make everything that you need.
 

FAQ: How to predict a magnet's field strength?

1. How is magnetic field strength measured?

The strength of a magnetic field is measured in units called gauss or tesla. Gauss is more commonly used for small magnetic fields, while tesla is used for larger fields. To measure the field strength, a magnetometer is used which contains a small, lightweight magnet that is placed near the magnet being tested. The force between the two magnets is then measured and the strength of the field can be calculated.

2. What factors affect the strength of a magnet's field?

The strength of a magnet's field is affected by several factors including the size and shape of the magnet, the material it is made of, the distance from the magnet, and any other nearby magnetic fields. The strength of the field is also dependent on the orientation of the magnet and the temperature.

3. How can the strength of a magnet's field be increased?

The strength of a magnet's field can be increased by using a stronger magnetic material, increasing the size of the magnet, or placing multiple magnets in close proximity to each other. Another way to increase the field strength is by increasing the electrical current in an electromagnet.

4. Can the strength of a magnet's field be predicted?

Yes, the strength of a magnet's field can be predicted by using mathematical equations such as the Biot-Savart law or Ampere's law. These equations take into account the shape, size, and material of the magnet as well as the distance from the magnet and any other magnetic fields present.

5. How does distance affect the strength of a magnet's field?

The strength of a magnet's field decreases with distance. The farther away from the magnet, the weaker the field becomes. The exact relationship between distance and field strength depends on the size and shape of the magnet, but it follows an inverse square law, meaning that as distance increases, the strength of the field decreases exponentially.

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