Properties Of a Magnet
Check us out at http://www.tutorvista.com A feature of magnets is the ends acting differently from each other. While one end attracts, the other end repels. Thus magnet ends are called poles, and in particular, a magnet itself is referred to as a dipole. An interesting aspect of magnets is when suspended by a string, they always align themselves in a North-South direction. For this reason, magnet poles are correspondingly labelled North and South. Lines of force emanate from the North pole and return to the South pole. Source of Magnetism If one was inquisitive, it would be tempting to see what happens if a magnet is chopped in pieces. Surprisingly, each piece retains its magnetic properties, no matter how small the piece. This gives the idea that at the microscopic level, there must be some fundamental magnetic domain •When an iron object is unmagnetized, the domains consisting of N-S dipoles, lie in random directions •When the object is placed in a magnetic field, the internal domains line up with each other, giving rise to a net magnetic field This magnetic field is said to be induced by the external field of the magnet. As soon as the external magnet is removed, the object is observed to lose its magnetism: domains return to their random states and the induced field disappears. The object only makes a temporary magnet.