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"Camilo" <camilogil@[EMAIL PROTECTED]
> wrote in message
news:43e07b13-59fc-46d7-9a4d-6dfed7ea1c7c@[EMAIL PROTECTED]
everybody! As I understand when you face two magnets by the same
pole, no matter if one of the magnets is very weak, they always get
rejected between them.
Well, guided by this premise, I tried to achieve this objective, but
replacing the weak magnet by a weak electromagnet, with an "I" shaped
ferromagentic core, and 15 meters of 36 number gauge used for the
coil, and supplied by a 9 volts battery. I must to clarify that I made
several experiments by changing the cross area of the core, but using
always the same lenght of wire (because I need to obtain in every
experiment approximately the same DC resistance). Obviously the
resulting number of turns is smaller when higher cross section is
used.
Ok, so the question is, no matter which cross section you use ¿why
always electromagnet get attracted to the magnet?
I´m sure that they are faced by the same pole when I perform the
experiment and electromagnet works properly, the only thing is that
its power isn´t too much; so finally, Is the problem here that the
mentioned premise doesn´t apply to magnet-electromagnet interaction?
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If your electromagnet wasn't energized, the permanent magnet would attract
the core. The characteristic of the permanent magnet is to have nearly
constant flux and it acts like an electromagnet with possibly several
thousand ampere turns ( and a big fat B-H curve) so that a change in the
air gap doesn't change the field much. Similarly introducing a relatively
few ampere turns is going to have only a bit more than effect as peeing in
Lake Superior is going to have on the water level- it doesn't change the
flux pattern or magnitude appreciably. If you used a strong electromagnet
you would see a difference but if strong enough, the permanent magnet
could
be demagnetized.
A better explanation would require a fair amount of background information
and math.
--
Don Kelly dhky@[EMAIL PROTECTED]
the X to answer
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