Vocabulary

is a continuous and closed path of an electric current. An electric circuit consists of electric devices, a source of electricity and wires that are connected with the help of a switch.

is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources.

current in a generator - in the case of a machine with field coils, a current must flow in the coils to generate the field, otherwise no power is transferred to or from the rotor. The process of generating a magnetic field by means of an electric current is called excitation.