Section outline

  • Chapter 3 introduces time-dependent regimes using the Quasi-Stationary Regime approximation (ARQS), valid for low-frequency variations where propagation effects are negligible.

    ARQS assumes spatial uniformity over the observation domain at each instant, neglecting displacement current in Maxwell-Ampère's law relative to conduction current. This simplifies analysis of induction phenomena, like varying magnetic fields inducing emfs in circuits.

    Focuses on time-varying fields from oscillating currents or dipoles, deriving retarded potentials while approximating static-like solutions for antennas and slow motions. Prepares for full wave propagation in later chapters.