magnetic field

magnetic field Region surrounding a magnet, or a conductor through which a current is flowing, in which magnetic effects, such as the deflection of a compass needle, can be detected. A magnetic field can be represented by a set of lines of force (flux lines) spreading out from the poles of a magnet or running around a current-carrying conductor. The direction of a magnetic field is the direction a tiny magnet takes when placed in the field. Magnetic poles are the field regions in which magnetism appears to be concentrated. If a bar magnet is suspended to swing freely in the horizontal plane, one pole will point north; this is called the north-seeking or north pole. The other pole, the south-seeking or south pole, will point south. Unlike poles attract each other; like poles repel each other. The Earth's magnetic poles are the ends of the huge ‘magnet’ that is Earth.