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Module 2: Basic elements & phasors

Useful Equations

Resistor: $$ I_m = \frac{V_m}{R} \text{ , } i_R(t) \text{ and } v_R(t) \text{ are in phase.} $$

Inductor: $$ X_L = \omega L \text{ , } v_L(t) \text{ leads } i_L(t) \text{ by 90}^o. $$

Capacitor: $$ X_C = \frac{1}{\omega C} \text{ , } i_C(t) \text{ leads } v_C(t) \text{ by 90}^o. $$

Average Power: $$ P = \frac{V_mI_m}{2}cos(\theta) = V_{rms}I_{rms}cos(\theta) $$ Resistive load: $$ P = V_{rms}I_{rms} = I_{rms}^2R = \frac{V_{rms}^2}{R} $$

Power Factor: $$ F_P = cos(\theta) = \frac{P}{V_{rms}I_{rms}} $$