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Thread: Electromagnet vs. Permanent magnet

  1. #1 Electromagnet vs. Permanent magnet 
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    Do both form the same field lines in iron powder given equal characteristics (orientation, strength, etc...)?

    The electromagnet would be a "pure" electromagnet without any external metal coupled to it; in other words just a simple copper coil in free space, like an air core inductor.


    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

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    It will be the same field lines. There will be also advantages and disadvantages either.


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  4. #3 Re: Electromagnet vs. Permanent magnet 
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    Quote Originally Posted by Cold Fusion
    Do both form the same field lines in iron powder given equal characteristics (orientation, strength, etc...)?

    The electromagnet would be a "pure" electromagnet without any external metal coupled to it; in other words just a simple copper coil in free space, like an air core inductor.
    A magnetic field is what is meant by the colloquial term "field lines" and the source of the field is immaterial.
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  5. #4 Re: Electromagnet vs. Permanent magnet 
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    Quote Originally Posted by Cold Fusion
    Do both form the same field lines in iron powder given equal characteristics (orientation, strength, etc...)?

    The electromagnet would be a "pure" electromagnet without any external metal coupled to it; in other words just a simple copper coil in free space, like an air core inductor.
    Do not forget that the magnetic field created by a permanent magnet is also due to electric currents. Yes, I am thinking in terms of an oversimplified model of orbiting electrons belonging to atoms and molecules.
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    Mmm...interesting.

    Thank you.
    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

    -Einstein

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    Use your computing strength for science!
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  7. #6  
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    Another idea....do static electric fields such as those found on capacitor plates also generate field lines? If so...then do they just propagate in all directions evenly if there is no opposite field for them to couple to?

    Can magnetic fields be said to propagate infinitely like gravity, or is there an absolute and definite boundary to their size? Perhaps static fields can if they have no opposing field to couple with?

    I am interested in this because I do not see a reason as to why the fields are not evenly distributed, but rather are in the form of lines.
    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

    -Einstein

    http://boinc.berkeley.edu/download.php

    Use your computing strength for science!
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  8. #7  
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    Quote Originally Posted by Cold Fusion
    Another idea....do static electric fields such as those found on capacitor plates also generate field lines? If so...then do they just propagate in all directions evenly if there is no opposite field for them to couple to?

    Can magnetic fields be said to propagate infinitely like gravity, or is there an absolute and definite boundary to their size? Perhaps static fields can if they have no opposing field to couple with?

    I am interested in this because I do not see a reason as to why the fields are not evenly distributed, but rather are in the form of lines.
    1) Electric field lines are generated by electric charges. Plates on which net electric charges reside do generate field lines. But plates without charges do not generate them.

    2) Yes Electric field lines "couple to," as you say to other charges. And yes, electric field lines of a single charge "couple to" infinity.

    3) Magnetic poles are not like electric charges. They exist in pairs. That is magnetic field lines (unlike electric and gravitational lines) do not "couple to" infinity.
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  9. #8  
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    Quote Originally Posted by Cold Fusion
    Another idea....do static electric fields such as those found on capacitor plates also generate field lines? If so...then do they just propagate in all directions evenly if there is no opposite field for them to couple to?

    Can magnetic fields be said to propagate infinitely like gravity, or is there an absolute and definite boundary to their size? Perhaps static fields can if they have no opposing field to couple with?

    I am interested in this because I do not see a reason as to why the fields are not evenly distributed, but rather are in the form of lines.
    Fields are NOT in the form of lines. Field lines are nothing more than a rather imperfect means of visualizing fields. What you are dealing with are vector fields. How you depict them graphically is simply a matter of convenience.

    Static fields do not propagate. That is why they are static.
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    Mmmm....then why does iron dust placed on a sheet with a magnet underneath form the shape of lines? I can think of no other reason than the idea that they are attracting to literal spherical 'globes' of magnetic force, which on a 2d plan like that of a paper sheet, appear as regular curving lines.
    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

    -Einstein

    http://boinc.berkeley.edu/download.php

    Use your computing strength for science!
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  11. #10  
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    Quote Originally Posted by Cold Fusion
    Mmmm....then why does iron dust placed on a sheet with a magnet underneath form the shape of lines? I can think of no other reason than the idea that they are attracting to literal spherical 'globes' of magnetic force, which on a 2d plan like that of a paper sheet, appear as regular curving lines.
    I am quite certain that YOU can think of no other explanation.

    Go learn something about electromagnetic theory. Read a book. Jackson's Classical Electrodynamics is the usual graduate text.
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  12. #11  
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    Haha, such amazing condescension.

    But I will not try to justify myself; if you disagree then that is fine, it cannot be helped.

    Oh, thanks kowalskil for your answer and minding my jargon. So far my method of thought has led to great success, so I am sticking with it.
    Of all the wonders in the universe, none is likely more fascinating and complicated than human nature.

    "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."

    "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence"

    -Einstein

    http://boinc.berkeley.edu/download.php

    Use your computing strength for science!
    Reply With Quote  
     

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