How AC Circuits Really Work — The Geometry Hidden Inside Every Equation

You've seen the equations for impedance, reactance, and phase shift — but have you ever seen where they actually come from? This video strips away the calculus and reveals the simple geometry hiding inside every AC circuit equation. Using rotating vectors (phasors) and basic triangles, you'll finally see why current leads in a capacitor, lags in an inductor, and how resistance, reactance, and impedance all connect through one elegant visual framework. 🔗 Related Videos: ▶ What are Resistance, Reactance & Impedance:    • Why V × I Gives the WRONG Answer in AC Cir...   ▶ AC Circuit Analysis Using Complex Numbers:    • AC Circuit Analysis Using Complex Numbers ...   ▶ Capacitors Explained:    • Capacitors Explained: Charging, Dischargin...   ▶ Inductors Explained:    • The Hidden Power of Inductors — Why Coils ...   📋 Full Series — Passive Components:    • Passive Components — How They Really Work   📋 Circuit Analysis Toolkit:    • Circuit Analysis Toolkit — Solve Any Circuit   🎯 Support ProfMAD:   / profmad   ⏱️ Chapters: 0:00 What is AC and how does an alternator create it? 0:58 Rotating vectors — how phasors represent AC signals 2:43 What "out of phase" really means 3:48 From frequency to angular velocity 4:42 How resistors behave in AC circuits 6:25 Capacitive reactance — why current leads voltage 8:10 Inductive reactance — why current lags voltage 11:24 Analyzing an RC circuit with vector triangles 15:32 Analyzing an RL circuit with vector triangles 17:30 Analyzing an RLC circuit — combining all three 23:40 What impedance really means