Electromagnetic Repulsion Power

  • Thread starter Jakeeis
  • Start date
  • #1
4
0

Main Question or Discussion Point

So I coiled ~3' of 28awg wire in a 1/4" coil and connected it to an AA battery. It is unable to pick up nuts but still attracts and repulses in the presence of a permanent magnet. When a piece of iron is added to the center of the coil the strength of the magnet increases, as expected, and it is now able to pick up nuts. The problem is that now both poles of the permanent magnet are now attracted to the iron core. How can I achieve repulsion with the electromagnet? Would more turns or voltage help?

Thanks for your help!
 

Answers and Replies

  • #2
davenn
Science Advisor
Gold Member
2019 Award
9,139
7,113
The problem is that now both poles of the permanent magnet are now attracted to the iron core. How can I achieve repulsion with the electromagnet? Would more turns or voltage help?
Hi
and welcome to PF :)

yes many more turns and a few more volts....
At the moment the magnetic attraction of the permanent magnet to the iron core far exceeds the magnetic field strength of your electro magnet

cheers
Dave[/QUOTE]
 
Last edited by a moderator:
  • #3
sophiecentaur
Science Advisor
Gold Member
24,300
4,323
How can I achieve repulsion with the electromagnet? Would more turns or voltage help?
The permanent magnet is obviously a lot stronger than your electromagnet so the induced magnetisation in the iron, due to the permanent magnet - and which will cause attraction, is stronger than any magnetisation that your electromagnet can produce. So the net resultant of the two magnets still causes attraction. If you could actually measure the forces involved, I am sure you would measure a smaller force with your electromagnet on 'repel' setting. You could use a small Force Meter or weak spring or you could even hang the iron on a string cradle and see if the angle it hangs at is altered with and without current flowing.
 
  • #4
4
0
That makes sense. But does this mean that the repulsion force will always have a lower magnitude than the attraction force?
 
  • #5
davenn
Science Advisor
Gold Member
2019 Award
9,139
7,113
until you make the electromagnet stronger, yes
 
  • #6
4
0
Thanks for your help!
 
  • #7
sophiecentaur
Science Advisor
Gold Member
24,300
4,323
That makes sense. But does this mean that the repulsion force will always have a lower magnitude than the attraction force?
The Iron is passive and will take a 'polarity' which is due to the stronger of the two fields. So you will always have a field vector that is a product of the cancellation of the two fields you put it in. The resultant will always be less in magnitude than either of the two.
I don't think there is anything inherently asymmetrical about the situation you describe so your 'repulsion' term only means 'attraction' to the other (winning) magnet.
 

Related Threads on Electromagnetic Repulsion Power

  • Last Post
Replies
6
Views
3K
  • Last Post
Replies
12
Views
926
  • Last Post
Replies
3
Views
3K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
5
Views
4K
  • Last Post
Replies
6
Views
3K
  • Last Post
Replies
11
Views
5K
  • Last Post
2
Replies
29
Views
4K
  • Last Post
Replies
9
Views
7K
Top