Permanent Magnet vs Electromagnet Attraction

  • Context: Undergrad 
  • Thread starter Thread starter Kirua
  • Start date Start date
  • Tags Tags
    Magnet
Click For Summary

Discussion Overview

The discussion revolves around the interaction between a permanent magnet and an electromagnet, particularly focusing on the effects of the electromagnet's soft-iron core when both are positioned with their poles facing each other. Participants explore the theoretical implications of magnetic fields, attraction forces, and the potential for experimental verification.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether a permanent magnet would attract to the soft-iron core of an electromagnet, assuming both have similar strength and dimensions.
  • Another participant suggests that the total magnetic field will affect the iron core, indicating a need for experimental verification.
  • A participant emphasizes that the iron core will be influenced by the magnetic field of the electromagnet, but also acknowledges the potential influence of the permanent magnet's field.
  • There is a discussion about whether a magnet interacts with a magnetic field solely through its own magnetism or if it also behaves as a non-magnetic metal, raising questions about induced currents.
  • Another participant introduces a scenario involving two magnets with equal pulling energy and an iron strip placed between them, asking how to calculate the force exerted on the strip and whether the total attraction force would be doubled.
  • There is a request for clarification on the calculations related to the forces involved with magnets and iron strips, including a reference to a data sheet for a specific magnet.

Areas of Agreement / Disagreement

Participants express differing views on the nature of magnetic interactions and the effects of the electromagnet's core. There is no consensus on the specific outcomes of the interactions or the calculations involved.

Contextual Notes

Some assumptions about the experimental setup and the definitions of magnetic interactions remain unresolved. The discussion includes various hypothetical scenarios that may not have been fully explored or clarified.

Kirua
Messages
12
Reaction score
0
If I have a cylindrical permanent magnet and an electromagnet with both poles facing each other, would the permanent magnet attract to the soft-iron core of the electromagnet? Assuming both magnets are restricted on an axis and have +/- equal strength (~375lb pull force, 2" cross sectional diameter).

I would assume the electric current would temporary magnetize the soft-iron core, thus temporary eliminating its attraction force. But I am not sure.
 
Physics news on Phys.org
You should be able to discover the answer by experiment :)

The iron core will, of course, be affected by the total magnetic field it is subject to wouldn't it?
 
The iron core will, of course, be affected by the total magnetic field it is subject to wouldn't it?

That's what I'm trying to find out. Also, I am short of equipment to perform an experiment. :(
 
You just said you had an electromagnet and a permanent magnet - after that you just need a spring and a ruler.
 
I said "If" I have a electromagnet and a permanent magnet...
 
My mistake. Well, if they are not easy to get then you have bigger problems to take care of first :)

Think of the core of the electromagnet as just a lump of iron ... don't let it's purpose distract you, that a human assignment not a physical one. The coil is an electromagnet whether it has a core or not.

No matter where that lump of iron is, it will be affected by the total magnetic field there. Make sense?

If the iron is inside the coil, then it is most affected by the coil's field ... this is not to say that it is not affected by the magnet's field. The effect may be so small wrt the coil that it can be neglected in the math though.

The core question is wether a magnet interacts with a magnetic field only through it's own magnetism or if it also reacts as a lump of non-magnetic metal in addition. For instance, if you move a magnet towards a metal magnet, is there a current induced in the magnet(s) to oppose the motion?
 
Force exerted on iron beetwen repelling magnet

Force to an iron between 2 magnets
Two magnets (A and B)has the same pulling energy @ 50 lbs. Put face by face on the same north poles (in repelling mode) within 10 mm distance. If a 3 mm bar iron strip/steel trip put in the middle of these 2 magnets, What will the forcstrip irone exerted on the strip iron/steel ? Howdo you calculate ?

Best regards

Windu Hernowo
++++++++++++++++
 


hernowo said:
Force to an iron between 2 magnets
Two magnets (A and B)has the same pulling energy @ 50 lbs. Put face by face on the same north poles (in repelling mode) within 10 mm distance. If a 3 mm bar iron strip/steel trip put in the middle of these 2 magnets, What will the forcstrip irone exerted on the strip iron/steel ? Howdo you calculate ?

I found a data Sheet for a 47.75lb magnet:
h-ttp://www.kjmagnetics.com/proddetail.asp?prod=DEX2
(p.s. is there an equation are to how they got those numbers?)

I have a question, if the iron strip is placed in the middle of the 2 magnets, would the total force of attraction be doubled that of the iron strip-magnet attraction force?
 

Similar threads

  • · Replies 0 ·
Replies
0
Views
461
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K