ABSTRACT
This chapter explains the need for external negative and positive potentials to cause current in a conductor and describes simple electric field patterns. It provides state the SI unit of measurement of potential difference. The chapter contains the differences between each of the following terms: potential difference, voltage, electromotive force and potential. The chapter also explains the terms, potential and potential difference in terms of charge movement within electric fields and explores what is meant by 'charge separation'. The area surrounding an electric charge, in which the effects of that charge may be observed, is termed an 'electric field'. An electric field is graphically represented using lines of force, called 'electricflux'. The imaginary and magnetic flux lines emanate perpendicularly from an electric charge and spread out in all directions towards infinity with individual flux lines repelling adjacent flux lines. It is conventional to allocate a direction to electric flux lines using arrow heads.
