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Object being magnetise from afar

  1. Mar 31, 2012 #1
    Is it possible to magnetize something from afar with a strong magnet. If it is possible, how much tesla will it need?
  2. jcsd
  3. Mar 31, 2012 #2


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    Could you be just a bit more vague in your question? How much magnetism do you want to induce? How far away is "afar"? An inch? A mile? From the other side of the earth?

    The earth's magnetic field is very weak (relatively speaking) but it magnetizes rocks in the earth's crust (weakly) over long periods of time, so I'd say yes, you definitely can do it, BUT I doubt you can induce much magnetism from any substantial distance.
  4. Mar 31, 2012 #3

    jim hardy

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    I walked into my workshop one day after a thunderstorm and found the FM radio wouldn't work. I opened it and found capacitors in the tuner blown apart , pesumably by a lightning strike in vicinity of my outdoor antenna.

    Next day i noticed two magnetic compasses i keep near workbench pointed South instead of North. I called Silva and spoke with their engineer, he said to send them back for remagnetization.

    I did it myself with a soldering gun. Found it quite easy.

    So part of your answer is "Yes it can be done"

    but i have no idea as to field strength required.
    For fun, take a soldering gun and hacksaw blade and feel how strong it vibrates when held near the high current heating element. You could measure flux with an open coil and calculate a ballpark answer i think. That'd give a number for the iron in compass needles, at least.

    just an approach .
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