Can You Control the Strength of a Magnetic Field with Obstructions?

[Math Jeans]

I've been somewhat curious about this for a little while:

Is there a way to obstruct a magnetic field so that it is weaker in one area and stronger than another.

I have attached a picture of what I'm kind of looking for, but also anything that could cause the same effect in terms of focusing the field into one place would be very helpful as well (like would a coiled magnet do this effectively?).

 

[marcusl]

You can reduce the field in a region by applying shielding consisting of sheets of iron (or iron alloys). See the following sites for more information:

http://www.advancemag.com/ShieldDesign.htm
http://www.magnetic-shield.com/idx-rd.html

 

[pallidin]

Without knowing your desired use, if you are hoping to construct a 'pseudo" magnetic monopole for PMM application, good luck. Shielding won't work, and damping will but requires energy applied thus negating PMM.

Then again, I have no idea what you are eventually after.

If you could explain your application, I might be of some help.

 

[Vanadium 50]

Magnetic field lines emerge from one point in the magnet, and enter another point: they don't form circles around the magnet like you've drawn.

There's a property of field lines that makes them very useful for understanding if a given field condition is possible: remember that you cannot change the entrance and exit points for a given field line at the magnet, but in between, you can reroute the field lines any way you like, provided that two lines never touch each other.

 

[pallidin]

Magnetic field lines emerge from one point in the magnet, and enter another point: they don't form circles around the magnet like you've drawn.

There's a property of field lines that makes them very useful for understanding if a given field condition is possible: remember that you cannot change the entrance and exit points for a given field line at the magnet, but in between, you can reroute the field lines any way you like, provided that two lines never touch each other.

Right, I had also noticed the drawing to be inaccurate, but I ignored it assuming the OP knows about field lines and chose to draw a simplistic(albeit inaccurate) diagram for his question.

In any event, V-50, I have a question related to the OP's query:

Do magnetic fields from a permanent magnet actually express in discreet "lines of force"?
If so, is their a magnetic force "in-between" those lines?

Or, are the "lines" merely an artifact of measurement techniques(iron filings, for example)

I'm not sure I asked this well... hope you can understand my questions.

 

[Vanadium 50]

The lines are imaginary (but nevertheless useful). One could use different measurement units and get different numbers of lines. (The iron filing lines you see depend on the size of the filings)

 

[canadmonster]

i am not great in physics and i am learning . it looks like you have a ball or circle there. maybe you could construct your circle or ball out of different metals or non metals . The area where you want less magnetism could be a non magnetic substance of equal weight or non equal weight, depending on what you want to construct. Correct me if i am wrong, just a newbie buff here.

 

[canadmonster]

non magnetic i mean like clay or plastic or other material. a combination to try to achieve your goal

 

[Math Jeans]

Ok. I appreciate your help.

In terms of what I was doing was transporting some sensitive electronics.

It all worked out fine.