Desperately need help on an idea I'm putting in my uni app!!

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Patrick Tew
Posts: 1
Joined: Wed Oct 12, 2011 1:02 pm

Desperately need help on an idea I'm putting in my uni app!!

Post by Patrick Tew » Wed Oct 12, 2011 1:07 pm

Hi guys,

Though this may not be the right place for help on a physics idea, it's really important for my uni application as it's a piece of evidence to demonstrate ability and I would hugely appreciative of any help you can give me!!

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:

My Idea
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!!

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Joined: Fri May 13, 2011 10:08 am

Re: Desperately need help on an idea I'm putting in my uni app!!

Post by beefpatty » Sat Oct 15, 2011 12:15 am

An object that is initially unmagnetized has its magnetic moments aligned in random directions. When you magnetize it you align those moments with an external B field, as you mentioned. Introducing another magnet would only align them even better, so it wouldn't become demagnetized. You would have to randomly assort their moments once again to demagnetize it.

My creds: 4th year Physics major, so take what you want from my explanation.

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