# Urgent Help Needed on Saturation, Coercivity and Energy Stored in a magnetic field

1. Oct 12, 2011

### Patrick Tew

Urgent Help Needed on Saturation, Coercivity and Energy Stored in a magnetic field!!

Hi guys,

I'm applying to university to study Natural Science and the deadline to apply is Friday. In my application it's crucial I demonstrate extra ability and I thought of using a recent idea I had when doing a thought experiment on magnets. But, since I thought of my idea, I have not been able to find the right resources to help me clarify my idea but I need to be sure of the physics so when I write the idea into the personal statement, I haven't said something that simply isn't true or I make a mess of explaining it. I'm desperate for some help on clarifying the physics of my idea, which goes as follows:

If you were to magnetize an object, you would do work to align it's domains. The energy invested would then be a kind of potential energy stored by the magnetic field. If you were then to bring this new magnet (1) to another magnet (2) facing opposite poles the two would repel each other. Increasing the strength of 2's magnetic field would increase the force between 1 and 2 until the force would be so big, it would cause a change to the internal structure of magnet 1, demagnetising it and so releasing the potential energy we invested into 1 to magnetize it in the first place.

Upon follow up of my idea, I thought this could be related/explained by saturation, coercivity and inductance, however having just come out of secondary school it's been hard trying to learn these concepts to understand if what I thought is correct.

Though this may be basic, poorly thought out or down right wrong, any clarification on if what I'm thinking is real physics would be massively appreciated as this could really effect my uni application! Thanks a lot!!

2. Oct 12, 2011

### Drakkith

Staff Emeritus
Re: Urgent Help Needed on Saturation, Coercivity and Energy Stored in a magnetic fiel

I THINK when you change the direction of the domains the energy isn't stored there, as it is used to overcome friction and othe effects. Most of it would be converted to heat I believe.