• Tags: strategy, phasor, calculation
• Difficulty: Advanced

Step 1: Identify circuit type (pure R/L/C, series LR/CR/LCR, parallel). Step 2: Calculate reactances: X_L = omegaL, X_C = 1/(omegaC). Step 3: Find impedance Z and phase angle phi. Step 4: Calculate current I = V/Z. Step 5: Find individual voltages: V_R = IR, V_L = IX_L, V_C = IX_C. Step 6: Calculate power: P = I^2R = VI*cos(phi). Common pitfalls: (1) Adding voltages algebraically instead of using phasor addition — V_R + V_L + V_C does NOT equal V_source. (2) Confusing peak and RMS values — power formulas use RMS. (3) In resonance problems, forgetting that V_L and V_C can individually exceed V_source. (4) For parallel circuits, add admittances (Y = 1/Z) instead of impedances. (5) At resonance in a parallel LC circuit, impedance is maximum (not minimum like series).