ABSTRACT
The concepts of potent ia l and transfer apply d i rec t ly to s imple electrical circuits. Ohm's law relates the applied voltage, £, in a circuit to the product of the current, / and resistance R,
E = iR, (1.1) where E is the potential difference or the work done in moving one charge in the field of another charge. The unit of potential is volt, V, w i t h one v o l t be ing equal to 1 j ou l e per C o u l o m b . Genera l ly the po t en t i a l difference is expressed w i t h respect to some reference level. Often, the level is called the ground, considered to be an infinite electrical sink.
