The magnet represents a metal subject which can attract to itself(himself) iron and some other metals. At magnets industrial and those that are used in training, as a rule, plus and minus are designated in color, under production conditions edges of the device cover with resistant paint. Become blue designate minus, and red - plus. Magnets which are used in mechanisms have no such designation, but when replacing parts and components with this device often it is required to find polarity.
Instruction
1. Bring closer a magnet to the iron paper clips scattered on a table. Being at some distance, the magnet will attract paper clips. If in a few minutes you remove paper clips from a magnet, you will find out that they began to have properties of a magnet. It occurs due to existence of magnetic field. As you noticed, the bigger quantity of paper clips was attracted by the ends of a magnet, that is to its poles. If you take two magnets and put one magnet on a table, and you will slowly bring closer the second to it, you will find out that poles of magnets can be attracted and make a start.
2. Therefore, for definition of plus at a magnet, it is possible to use other magnet which polarity is defined and noted. Bring magnets to each other. If they make a start, then poles at them identical.
3. For definition of plus at a magnet it is also possible to use a compass - the most known device in which the magnet is used, and it serves for definition of the sides of the horizon. Magnetic properties allocated an arrow of a compass. Always points north the blue end of an arrow of a compass, and on the South - red. Slowly bring a compass to one party of a magnet after the arrow of a compass is established in magnetic field of Earth. The southern arrow will indicate the North Pole of a magnet, and a northern arrow – on southern. Thus, you define where plus and where minus at a magnet.
4. It is possible to define magnet plus in one more way. For this purpose it is necessary to bring a magnet to the screen of the turned-on TV when on television, before the beginning or the end of broadcasting, the grid for control is transferred. If the central part of a grid is displaced in the opposite direction from a magnet, the field of a magnet positive means.
5. It is also possible to suspend a magnet for its central part on a string where nearby there are no metal objects. The South Pole of a magnet will indicate the South, and northern – the North.