Wrap some thin copper wire around the nail and connect it short circuited to a battery. The electric current that runs through the wire coils creates a magnetic field similar to the magnetic field of a stick magnet. A nail becomes a magnet. This experiment can be performed only with substances which are ferromagnetic (steel, iron, nickel or cobalt). These are substances which magnetic field density increases under the influence of the outer magnetic field (an electric current of a live wire). With this small electromagnet we can lift up paper clips or tiny screws and drop them, when we switch off the battery. Bigger electromagnets are used in industry for lifting heavy burdens. ATTENTION ! The wire, short circuited connected to the battery can be very warm! This is physics experiment for science project.
Okoli žeblja navijemo tanjšo izolirano žico in jo kratkostično priključimo na baterijo. Električni tok, ki teče skozi ovoje žic, ustvari magnetno polje, podobno polju paličastega magneta. Žebelj tako postane magnet. Ta poskus lahko izvedemo samo s snovmi, ki so feromagnetne (jeklo, železo, nikelj, kobalt). To so snovi, ki se jim gostota magnetnega polja zelo poveča pod vplivom zunanjega magnetnega polja (električni tok po žici). S takim elektromagnetom dvignemo sponke za papir ali drobne matice in jih spustimo, če izklopimo baterijo. Večje elektromagnete uporabljajo v industriji za dvigovanje težkih bremen. POZOR: Žica, ki je kratkostično priključena na baterijo, se lahko močno segreje!
