Circuit, Electric, Active

A circuit through which a current pa es. The circuit itself need only be a conducting ring, or endle wire. Generally it includes, as part of the circuit, a generator of electro-motive force, and through which generator by conduction, ordinary or electrolytic, the same current goes that pa es through the rest of the circuit. One and the same current pa es through all parts of a series circuit when such current is constant. force disappearing in its production in an active circuit, there must be some source of energy which will maintain electromotive force against the drain made upon it by the current. The simplest conception of an active electric circuit is a ring or endle conductor swept through a field of force so as to cut lines of force. A simple ring dropped over a magnet pole represents the simplification of this proce . In such a ring a current, exceedingly slight, of course, will be produced. In this case there is no generator in the circuit. An earth coil (see Coil, Earth,) represents such a circuit, with the addition, when experimented with, of a galvanometer in the circuit. In practice, a circuit includes a generator such as a battery or dynamo, and by conductors is led through a continuous path. Electric lamps, electrolytic cells, motors and the like may be included in it. The term "circuit" is also applied to portions of a true circuit, as the internal circuit, or external circuit. A certain amount of elasticity is allowed in its use. It by no means nece arily indicates a complete through circuit.