STUDY GUIDE · GKU 1
Electrical circuits study guide (Electrical Engineering)
Electrical circuits is the language the rest of electrical engineering is written in. The subject begins with two laws — Ohm's law and Kirchhoff's laws — and a set of reduction rules that turn a network of resistors into one equivalent resistance. It then adds the theorems that make analysis practical: Thevenin and Norton reduce a complicated network to a source and a resistance, while nodal, mesh and superposition methods solve for every current and voltage without guesswork. The second half moves to alternating current, where every quantity becomes a sinusoid with an amplitude, a frequency and a phase. Phasors turn the differential relations of inductors and capacitors into algebra with complex impedances, and the same algebra gives real power, reactive power, power factor and balanced three-phase quantities. Every section opens with a quick-revision card, and the worked examples run from easy to exam level.
Structured by the official ETEC subject standard for this topic: every listed topic and learning outcome, with formulas, figures and worked examples. The full sections are available to members in the app.
SKU 1.1 · Basic laws of circuits
Equivalent circuits and network reduction
Series and parallel combinations, the wye–delta transformation and source transformation, and why an equivalent circuit is only equivalent at its terminals.
Ohm and Kirchhoff: the basic circuit laws
Ohm's law with the passive sign convention, KCL and KVL, and the voltage and current divider rules with their loading limits.
SKU 1.2 · Advanced circuit analysis
Thevenin, Norton, nodal and mesh analysis
Reducing a two-terminal network to a source and a resistance, and solving the full network by nodal, mesh and superposition methods.
Sinusoids, phasors and impedance
RMS and average values, frequency, phase and wavelength, the phasor representation, and complex impedance for R, L and C circuits.
AC power, power factor and three-phase circuits
Real, reactive and apparent power, the power triangle, power-factor correction, and balanced three-phase power.