Electrical machines

Electric generators and motors are widely used due to the fact that electricity is a very convenient form of energy. Electricity generation is a fairly easy process, as the motors can perform different purposes, from drilling wells to ensuring the movement of trains.
Matter consists of atoms, and those, in turn - of electrically charged particles - protons and electrons. Even the ancient Greeks knew: if you RUB amber with a cloth it would attract light objects, but did not understand the reasons for what is happening. Actually occurred due to friction electricity.
Usually in any substance is the same number of negatively and positively charged particles. Therefore, their electrical charges are balanced, and the substance is neutral. However, as a result of friction, some electrons move from one material to another. As a consequence, disturbed the equilibrium of the charges: the material dragged by the electrons, becomes negatively charged, and the one that gave them positively charged.