1. Definitions and fundamental properties

1.1 Topological definitions and conventions

• Dipole: a dipole is an element connected to the outside by two terminals A and B, the current flowing into one being equal to that flowing out the other.

• Sign conventions: figure 1 shows the representation of a dipole and indicates the conventions for the current i flowing through it and the voltage v at its terminals.

  i is expressed in amperes and v in volts.

• Network: an electrical network (or circuit) is a set of interconnected dipoles.

  Figure