Ohm between two points of a conductor when a constant potential difference of one volt, applied to these points, produces in the conductor a current of one ampere, the conductor not being the seat of any electromotive force. in which the following units appear: volt (V), ampere (A), siemens (S), watt (W), second (s), farad (F), joule (J), kilogram (kg), metre (m), and coulomb (C). In many cases the resistance of a conductor in ohms is approximately constant within a certain range of voltages, temperatures, and other parameters. These are called linear resistors. In other cases resistance varies (e.g., thermistors). A
Inductance rate of change of current in circuit formula_7. This is the principle behind a "transformer". The sections below will describe self-inductance, the effect of inductance in a single conductor or circuit. Mutual inductance, inductance between circuits, is described in the section at the end. If the current through a conductor with inductance is increasing, a voltage formula_20 will be induced across the conductor with a polarity which opposes the current, as described above (this is in addition to any voltage drop caused by the conductor's resistance). The charges flowing through the circuit lose potential energy moving from the higher voltage