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Author Topic: How does this experiment work?  (Read 2367 times)

Offline thebrain13

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How does this experiment work?
« on: 29/04/2010 04:49:16 »
I was doing a couple experiments using the magnets around my house, and there was one experiment I did not get. This is how it works. I had a permanent magnet on a smooth table. I also had some paperclips, and a piece of ferromagnetic material (the metal on a pair of scissors). What I did is I put the scissors next to the magnet and saw how the scissors would affect the strength of the magnetism. I could see how the strength of the force would change by moving the magnet slowly towards the paperclip to see how close I could get before the paperclip flew over to the magnet.

What I found was that, if you put the metal "behind" the magnet, meaning the metal was on the opposite side of the magnet in relation to the paperclip. So oriented in this way paperclip(left) magnet(middle) metal(right). When I did this I got the result I was expecting, this increases the strength of magnetic force, the magnet could pull the paperclip a further distance, than if there was no metal behind it.

However when you do the inverse of this experiment, when you put the metal in between the magnet and the paperclip. It doesn't increase the strength of magnetism, it reduces it. The magnet can get even closer to the paperclip than if the metal wasn't there at all. Why does this happen?


 

Offline Soul Surfer

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How does this experiment work?
« Reply #1 on: 29/04/2010 08:54:57 »
The presence of ferromagnetic material between a magnet and an object can act as a magnetic screen if it is a thin layer placed across the path of the field  however if it is placed along the direction of the field the induced poles in the material can effectively increase the field at a distance from the magnet
 

Offline thebrain13

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How does this experiment work?
« Reply #2 on: 29/04/2010 16:25:55 »
The presence of ferromagnetic material between a magnet and an object can act as a magnetic screen if it is a thin layer placed across the path of the field  however if it is placed along the direction of the field the induced poles in the material can effectively increase the field at a distance from the magnet

I always thought that the magnetic field strength was just the composite of all the individual magnetic fields. I thought the "magnetic screen" was just an illusion. Do you know what the effect is called?

Another note about the experiment is that the magnetic field lines point in the direction of the paperclip. That is, the north and the south side of the magnet is aligned from left to right. So to be more specific.

the lineup is this.  (paperclip) (ferromagnetic material) (north end of magnet) (south end of magnet)
 

Offline Geezer

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How does this experiment work?
« Reply #3 on: 29/04/2010 18:15:07 »
You are altering the magnetic circuit in your experiments. By introducing pieces of steel, you are altering the path of least resistance to the magnetic flux.
 

Offline tommya300

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How does this experiment work?
« Reply #4 on: 20/05/2010 07:15:00 »
I was doing a couple experiments using the magnets around my house, and there was one experiment I did not get. This is how it works. I had a permanent magnet on a smooth table. I also had some paperclips, and a piece of ferromagnetic material (the metal on a pair of scissors). What I did is I put the scissors next to the magnet and saw how the scissors would affect the strength of the magnetism. I could see how the strength of the force would change by moving the magnet slowly towards the paperclip to see how close I could get before the paperclip flew over to the magnet.

What I found was that, if you put the metal "behind" the magnet, meaning the metal was on the opposite side of the magnet in relation to the paperclip. So oriented in this way paperclip(left) magnet(middle) metal(right). When I did this I got the result I was expecting, this increases the strength of magnetic force, the magnet could pull the paperclip a further distance, than if there was no metal behind it.

However when you do the inverse of this experiment, when you put the metal in between the magnet and the paperclip. It doesn't increase the strength of magnetism, it reduces it. The magnet can get even closer to the paperclip than if the metal wasn't there at all. Why does this happen?

Johann Carl Friedrich Gauss I presume.

An easy way to visualize the magnetic field is to use an old plastic tray tape the magnet to the center outside bottom of it. Turn it back over and block up each end just enough of clearance. Sprinkle iron filings in the top where the magnet would be underneath it. Watch and see the mag field. Now outside this tray underside place the steel sizzers orientating them as you did the way you explained before. Watch the filings change position.  This help?
« Last Edit: 20/05/2010 07:25:33 by tommya300 »
 

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How does this experiment work?
« Reply #4 on: 20/05/2010 07:15:00 »

 

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