交流回路の計算とフェーザと位相の基礎を分かりやすく解説【電験三種理論】

The terms "reactance," "impedance," and "complex number j" suddenly appear in AC circuit calculations. You may know the formulas, but why the j? Why is it +j for inductors and -j for capacitors? —Are you just memorizing the calculations without understanding their meaning? This video explains everything from the true nature of reactance to phase calculations using complex numbers, step by step, in a way that beginners can truly grasp. Instead of simply memorizing formulas, this video helps you understand "why this calculation represents phase" by actually drawing phasor diagrams. ▼What you will learn from this video ・What is reactance? (Difference between inductive and capacitive) ・The difference between DC resistance and AC impedance ・What does ω represent in the equations ωL and 1/ωC? ・Why is the imaginary unit j used in reactance calculations? ・Why are coils +j and capacitors -j? ・Understanding phase shifts visually using phasor diagrams ・How coils delay current by 90° and capacitors advance it by 90° ・The concept of RLC circuits and impedance ▼Recommended for: ・Those studying for the Class 3 Electrical Engineer Examination on their own ・Those struggling with AC circuit calculations ・Those calculating without understanding the meaning of "j" ・Those who want to overcome their complex number aversion ・Those struggling to remember the phase lead and lag of coils and capacitors Reactance and complex numbers are extremely important topics that cannot be avoided when solving AC circuit calculation problems. If you grasp this point not through rote memorization but through understanding its meaning, you'll be able to smoothly transition to applied topics such as RLC circuits, resonance, and power factor correction. Let's make this a source of points! #ElectricalEngineerExam #ChiefElectricalEngineer #Reactance #Impedance #ComplexNumbers #ACCircuits #Theory ▼Related Videos For those who want to learn more about phase lead and lag, click here:    • 【電験3種理論】位相とは？位相差と遅れと進みの見分け方の解説【交流回路】   Video explaining what reactance is:    • リアクタンスとは？分かりやすく解説【電験三種理論】   Video explaining phasors in detail:    • 【電験3種理論】交流計算のフェーザとは何かをやさしく解説【交流回路】