Permanent Magnet vs Electromagnet Attraction

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SUMMARY

The discussion centers on the interaction between a cylindrical permanent magnet and an electromagnet with a soft-iron core. It is established that the soft-iron core will be temporarily magnetized when current flows through the electromagnet, affecting its attraction to the permanent magnet. The total magnetic field influences the core's behavior, and while the core is primarily affected by the electromagnet's field, the permanent magnet's field also plays a role, albeit potentially negligible in calculations. The conversation highlights the need for experimentation to fully understand these interactions.

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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.
 
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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 ?

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Windu Hernowo
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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?
 

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