When speak about use of electric energy in life or transport, mean work of electric current. Electric current is brought to consumption sources from power plant on wires. The word "current" means the movement or a current something. What can move in the wires connecting stations to consumers of the electric power?
Instruction
1. In bodies there are electrons by which movement various electric phenomena are explained. Electrons possess negative electric charge. Electric charges also larger particles of substance – ions can possess. Therefore, in conductors various charged particles can move. Electric current is ordered (sent to one party) the movement of charged particles.
2. Existence of electric current in substance requires performance of the following two conditions: 1) in substance have to there are free charged particles, i.e. such particles which can freely move on all volume of a body (otherwise they are called current carriers); 2) some force forcing them to move in a certain direction has to affect these particles. Both of these conditions will be satisfied if, for example, to take the metal conductor and to create in it electric field.
3. That current existed a long time in the conductor, it is necessary to support all this time in it electric field. Electric field in conductors is created and the long time can be supported by sources of electric current. In the presence of a current source in the conductor the direct current can be supported. It is impossible to imagine current in the form of the movement of electrons on straight lines. Because of interaction with other particles their movement will still have difficult and and a chaotic order.
4. It is impossible to see electrons in the conductor. It is possible to find it on actions which current can make. Thermal action of a tokapra course of current the conductor heats up. By this principle such electric devices as the iron, electroboilers, teapots, soldering irons, etc. are arranged. Chemical action a current tokaprokhozhdeniye in conductors through solutions of salts, acids and alkalis is followed by allocation on the metal conductors lowered in solution, substances which are its part. So, for example, passing current through solution of copper vitriol, it is possible to emit pure copper. Magnetic action the tokaprovodnik on whom current flows gains magnetic properties and begins to attract to himself iron objects. Physiological action of a tokapra passing through a living organism current causes reductions of muscles. Such action of weak currents is applicable in medicine.