What are domains in magnets and how do we determine poles?
1. A magnetic domain is region in which the magnetic fields of atoms are grouped together and aligned. You can think of magnetic domains as miniature magnets within a material. 2. How do we determine the poles? You normally cannot since the domains are randomly distributed and so the net magnetic effect is zero. However, if you magnetize the bar with electric current or using another permanent magnet, then its poles can be determined. If the material has high hysteresis value, some domains remain in the new aligned state and so the metal displays magnetic properties.
USING A COMPASS !!