Interpretation Now the first term represents the rate of increase of stored energy per unit volume. The second term represents the rate of working per unit volume of the field on the conduction currents J. These currents might result in the dissipation of energy in the resistance of the medium, ...
Kirchho ff s current law Kirchhoff's current law states that the algebraic sum of the currents entering a single node of circuit is zero. There are a number of assumptions underlying this statement. The first is that we know where the currents are in the sense that the currents flow on wires, we...
Kirchho ff s voltage law Kirchhoff's voltage law of lumped circuit theory states that the sum of the voltage rises in traversing any closed path in a circuit is zero. The voltage rises are of course differences in electric potential. The statement above is equivalent to the statement that the lin...
Level of treatment In this treatment of energy storage and power flow, some results will be advanced by inductive generalisation of formulae which can be established readily only in simple geometries. In this aspect the present chapter may appear to differ from earlier chapters, where an attempt...
Line charging waveforms The solution defined by equation 2.26 has the graph shown in Figure 2.10. The following observations may be made about the diagram. • There is no activity at the load until the time T for a one-way propagation of signals on the line has elapsed. • The initial step at tha...
Line open circuit at load end and fed from a low impedance source There are many reflections from both the load and source ends of the line. The reflection factor at the load end is unity, and there is thus no attenuation of the wave reflected from the load end. The reflection factor at the sourc...
Linear crystalline dielectric If a dielectric medium is in the form of a single crystal, it will generally exhibit different polarisation responses to electric fields in different directions. This behaviour is described by the equation P = ²0 χ≈ · E (5.6) where χ≈ is called the dimensionles...
Linear electrostatic case In the simple case of a distribution of point charges which are assembled from infinitely separated points into a final position in a linear homogeneous dielectric medium of dielectric permittivity ², it is possible to show from a study of the mechanical work done that ...
Linear lossless dielectrics In most non-crystalline dielectrics, at least for electric field strengths below that of dielectric breakdown, the polarisation is proportional to and in the direction of the internal electric field. This is expressed by the equation P = χe ²0 E (5.1) where χe is a d...
Linear lossy dielectric In some dielectric materials, losses involved in changing the state of polarisation cannot be entirely neglected. In these materials, we can sometimes write a linear differential equation relating the polarisation and its time rate of change, and the corresponding quantiti...
