IMPEDANCEBasic AC Reactive ComponentswhereZ_{T} = total impedance (W)V_{T} = total voltage (V)I_{T}= total current (A)Total current in a parallel R-C-L circuit is equal to the square root of the sum of the squares ofthe current flows through the resistance, inductive reactance, and capacitive reactance branchesof the circuit. Equations (8-15) and (8-16) are the mathematical representations of total currentin a parallel R-C-L circuit. Because the difference between I_{L} and I_{C} is squared, the order inwhich the quantities are subtracted does not affect the answer.I_{T} = (8-15)I^{2}_{R}(I_{C}I_{L})^{2}I_{T} = (8-16)I^{2}_{R}(I_{L}I_{C})^{2}whereI_{T}= total current (A)I_{R}= current through resistance leg of circuit (A)I_{C}= current through capacitive reactance leg of circuit (A)I_{L}= current through inductive reactance leg of circuit (A)Example: A 200 W resistor, a 100 W X_{L}, and an 80 W X_{C}are placed in parallel across a120V AC source (Figure 10). Find: (1) the branch currents, (2) the total current,and (3) the impedance.Figure 10 Simple Parallel R-C-L CircuitES-08 Page 16 Rev. 0

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