u have two magnetic bars and u dont know the poles of these two magnets.How can u know the poles?
414734
bring the magnets close to each other. If u feel any repulsion, that means u have tried joining opposite poles.\nWith this test u just come to know of the repulsive and attractive sides relative to a magnet. No qualitative nalysis of which is North pole and which is south cannot be done! But hey! If the bar magnet is painted red on one side, then that would be the north pole!
591035
Ferromags are substances that are strongly attracted by a magnetic substance. Some ferromagnetic  metals are iron, cobalt, nickel, gadolinium and dysprosium. To generate electricity from ferromags, take two iron sheets 5 cm wide. rub both of them using a bar magnet only in one direction for about 10 minutes. This will impart magnetic properties to d iron sheet. Then u arrange the sheets in such a way that u feel d force of attraction between the sheets. take a copper wire. make a loop out of it. rotate d loop in d space between d sheets with a constant frequency. Voila electricity generated at d ends of d loop
115436
With a Magnetometer. See below for more detail.
513594
No, the magnetic poles are off from the geographic poles by several miles (perhaps even hundreds of miles, I don't recall exactly how much).
244341
Look up the mecahnical univers 43? on magnetic induction.
610327
electromagnetic or magnetic fields. It is easiest to research and to do the practical of. Just place the magnets and use iron filings to measure it
1123749
Hey there:\n\nInteresting question, because a month ago, i stumbled upon a thrown away harddrive while walking my dog.  I desembled it while I was at home, and found inside it TWO EXTREMELY POWERFULL RARE EARTH MAGNETS.  Also, around on each side of these magnets, was a magnetic shield, that did not allow them to attract from one side, but yes from the other.  If I was you, look for any thrown away harddrive, they all have them, and you will also be getting an extremly powerfull magnet while you are at it.
673529
north and south poles
703613
If they are too strong to pull apart directly, try sliding them.\n\nIf this doesn't work, find an even stronger magnet and put something between it and the other two first.
560218
instead of counting the number of flux to determine the strength of the force, i suggest u hang a piece of metal on a string, then investigate the angle of the string when u put a magnet at different distance. Because with this experiment, u can calculate the force much more easily through the angel and length of the string with the knowledge of gravitational force.\n\nThe flux suggestion is good, but how do u determine the force? There r much more complicated theory behind it and they r less intuitive than gravitational force.
514548
I do not know unless it has a weak magnetic field around it or even static electricity
674108
The poles of any magnetized item will be at the extreme opposite points...in other words the positive will be as far as it can get from the negative.  In the case of a sphere this would be "top" and "bottom" not core and perimeter.  (Think of the Earth's magnetic poles!).
341358
The north and south poles will be at opposite ends of the object and will lie along the axis of the applied magnetic field that was used to produce the ring or marble magnet.\n\nThe poles in the case of the ring can be produced  on a line (axis) perpendicular to the ring (circle), or it can be produced along a line (axis) that passes through the ring material (the circle). Using the iron filings and multiple orientations will assist you in determining the general direction of the axis of the field, but will not tell you precisely where the poles are.
101591
See if it is attracted to a magnet?
702587
It won't be easy to calculate.  You can easily calculate the strength of the magnetic field of the electromagnet with the current and the number of turns.  But it's harder to know the field strength of the bar magnet, and even harder to calculate the force produced by the interaction between the fields.  Once you got that force, it's easy to compare that to the gravitational force on the mass of the bar magnet.  It's probably easier just to build it and try it.  All you really need is a coil of wire and a current.\n\nOnce you have the apparatus, borrow an instrument to measure the fields.  I'd have more fun with a ball bearing on a circular (non-magnetic) track, timing the current to make the ball move around the track, like a cyclotron.
152758
The measure magnetic fields with a magnetometer.
152782
If a bar magnet breaks into two, then there will be two magnets, each with a N and a S pole.