11.5 Particular Forms of Maxwell’s Equations
Maxwell’s equations as given in Section 11.2.2 are general and apply to all electromagnetic situations and for any type of
time dependency. In this sense, whenever there is a need to solve an electromagnetic problem, we can start with Eqs. (11.24)
through (11.27) or, if integral representation is more convenient, with Eqs. (11.28) through (11.31). However, more often
than not, there is no need to resort to the general system. For example, we might need to solve the equations at low
frequencies, in which case the displacement currents might be negligible or do not exist. In still other situations the current
densities or charge densities in the system, or both, are negligible. Some of these representations are particularly useful, and,
therefore, we discuss these here, before we apply them to particular electromagnetic problems in the following chapters. In
particular, the time-harmonic representation of the equations is often useful.