Pre-requisite: 75612+70320
Co-requisite: 75613
It is a common requirement of an electrical engineer to convey electrical energy from one place to another, whether for the purpose of power or information transport. A pair of conductors used for this purpose constitute a transmission line, and for any appreciable distance a.c. voltages and currents on the line must be regarded as a travelling wave - whether from a power station, in a radio receiver, or across a digital circuit board. The electric and magnetic fields associated with voltage and currents may be similarly propagated as a travelling wave; such fields also constitute the basis of electrical machines and are the cause of much unwanted interference. Therefore, an understanding of both wave propagation and electro- magnetic fields is essential in all branches of electrical engineering.