magnet
A magnet is an object that can attract iron and generate a magnetic field therebetween. The magnet in the narrow sense refers to the product of the magnetite, and the generalized magnet refers to an object or device that produces a magnetic field. Magnets as magnetic dipoles, can attract ferromagnetic substances, such as iron, nickel and cobalt and other metals. Pole is determined by the fine line hanging a magnet, pointing to the north of the magnetic pole is called the north pole or N pole, pointing to the south of the magnetic pole for the pole or S pole. (If the earth would like a large magnet, then the Earth's magnetic north pole is the S pole, the magnetotelluric is the N pole.) Magnet is different, the same pole is excluded. Guide the pole and the North pole to absorb, guide pole and guide pole repulsion, referring to the North and the North polar repulsion. Magnet is divided into permanent magnets and non-permanent magnets. Natural permanent magnets, also known as natural magnets, can also be made by artificial (the strongest magnets are neodymium magnets). Non-permanent magnets can only have magnetic properties under certain conditions, usually in the form of electromagnets, that is, the use of current to strengthen its magnetic field. ...