Superconductor: Magnetic Field Strength VS distance

Click For Summary

Discussion Overview

The discussion revolves around how the magnetic field strength of a superconductor varies with distance from its surface. Participants explore whether the magnetic field decreases according to the same principles as regular magnets, specifically questioning if it follows the 1/r^2 law or if it exhibits different behavior.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions how the magnetic field strength of a superconductor changes with distance, specifically asking if it decreases as 1/r^2 or in another manner.
  • Another participant asserts that the magnetic field produced by a superconductor does not have unusual properties and follows Maxwell's equations, attributing the stronger field to larger currents.
  • A participant expresses uncertainty about whether superconductors follow different power laws compared to other magnets, citing examples of different magnetic field behaviors from various configurations.
  • Another participant clarifies that the differences in magnetic field behavior are due to geometric considerations rather than any innate properties of superconductors.
  • One participant acknowledges their confusion but expresses satisfaction with the responses received.

Areas of Agreement / Disagreement

Participants generally agree that superconductors do not have fundamentally different magnetic field behaviors compared to regular magnets, but there is some uncertainty regarding the specific mathematical descriptions of these behaviors at varying distances.

Contextual Notes

Participants mention various configurations of magnetic fields and their mathematical representations, indicating that the discussion may depend on specific geometric arrangements and assumptions about the superconductors.

Albertgauss
Gold Member
Messages
298
Reaction score
38
Hi all,

Does anyone know how the magnetic field strength of a superconductor varies as distance from the outside of the superconductor?

Aside from a superconductor being able to creates a stronger magnetic field than a regular dipole, does the strength still go down as 1/r^2 or does it decrease by some other way?

Any webpages that show such graphs or formulas are helpful, if the superconductor B-field does decreases differently than normal magnets.
 
Physics news on Phys.org
Albertgauss said:
Hi all,

Does anyone know how the magnetic field strength of a superconductor varies as distance from the outside of the superconductor?

Aside from a superconductor being able to creates a stronger magnetic field than a regular dipole, does the strength still go down as 1/r^2 or does it decrease by some other way?

Any webpages that show such graphs or formulas are helpful, if the superconductor B-field does decreases differently than normal magnets.

I'm a bit confused here.

The magnetic field that is produced by a superconductor has no strange, unusual properties. Maxwell equations work perfectly well. It has a stronger field because it has a bigger current! That's it. There isn't any magic.

Zz.
 
I just wasn't sure if superconductors went as something different as 1/r^2. For example, a sphere of rotating charge produces a magnetic field that falls off as 1/r^3 when you get far from it, and I know there are magnetic fields that have 1/r^4 terms when you get far from the magnet. The magnetic field of a solenoid is constant--it never gets any weaker inside the coil no matter where you go. Not even talking about superconductors, regular magnets can have different math behaviors as you get far from them, depending on the configurations of the currents or atoms that make them. I just wasn't sure if superconductors followed different power laws as one moved away from them. I guess they are just like any other magnets, just stronger. If I had a superconducting magnet and moved away, it would be stronger than a regular magnet, but still diminish by 1/r^2 as you moved away from it.
 
There is no innate difference about the magnetic field of a superconductor. The differences you describe arise purely from geometric considerations. The only practical difference that you need to know about a superconductor is that its resistivity falls to zero when the material temperature drops below some critical value. That's it.
 
I thought so, but just wasn't sure. I got it. All good. Thanks for you help everyone!
 

Similar threads

Undergrad Relation between electric & magnetic fields in terms of field strength
  • · Replies 41 ·
2
Replies
41
Views
7K
Undergrad The difference between calculating energy from 1 vs. 2 magnets?
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Magnetic field strength of a stack of magnets
  • · Replies 7 ·
Replies
7
Views
4K
Graduate On the magnetic field in the Meissner effect
  • · Replies 3 ·
Replies
3
Views
15K
Undergrad Variation of the Strength of a Magnetic field?
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Can nested solenoids trap particles?
  • · Replies 12 ·
Replies
12
Views
1K
Undergrad Measuring Magnetic Field Strength of a Cylindrical Magnet
  • · Replies 3 ·
Replies
3
Views
2K
High School Experiment issues (electromagnetism)
  • · Replies 42 ·
2
Replies
42
Views
4K
Undergrad Directional magnetic field
  • · Replies 9 ·
Replies
9
Views
2K
Graduate What Superconductor Can Have The Highest Magnetic Field Strength?
  • · Replies 4 ·
Replies
4
Views
2K