Theoretical Electrical Engineering deals with the analysis of electrical circuits because they are the most characteristic structure of electrical engineering. Knowledge of the theory of electrical circuits is one of the basic knowledge used throughout the course of study. Thesis: Basic principles and methods of alternating electrical circuits (Kirchhoff's laws, Ohm's law, principle of superposition, Thevenin and Norton theorem, law of continuity, Faraday's law), linear electronic components (resistor, inductor, capacitor) frequency characteristics, solution of transient processes I and II. order, Laplace's transformation. Homogeneous line, primary and secondary parameters, wave impedance.