10 - Electrical and Electronics Principles

Abstract

This chapter discusses electrical and electronics principles. The concept of flux and potential difference enables a unified approach to be adopted for virtually all field type problems. In general, the flowing quantity is termed the flux and the quantity that drives the flow is called the potential difference. This consistency of method is equally applicable to problems in fluid flow, heat transfer, electrical conduction, electrostatics, and electromagnetism. In a metallic conductor that has a potential difference applied across opposite ends, free electrons are attracted to the more positive end of the conductor. It is this drift of electrons which constitutes the electric current and the effect is simply nature's attempt to redress an energy imbalance. Although the negatively charged electrons actually drift towards the positive end of the conductor, traditional convention gives the direction of the current flow from positive to negative. The electromotive force (e.m.f.) is that which tends to produce an electric current in a circuit. As e.m.f. is also measured in volts, the distinction between electromotive force and potential difference might at first appear rather subtle.