In an RC parallel circuit, E_T = 480 V, R = 50 k Ω , and X_C = 47 k Ω . What is the reactive power? A) 4.90 VARs B) 5.36 VARs C) 6.38 VARs D) 7.61 VARs

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Quizplus · Accepted Answer

Reactive power is given by Q = ET * IT * sin(θ), where ET is the total voltage, IT is the total current, and θ is the phase angle between the voltage and current. In a parallel circuit, the total current is the sum of the currents through each branch. The current through the resistor is IR = ET / R, and the current through the capacitor is IC = ET / XC. The phase angle between the voltage and current in the resistor is 0°, and the phase angle between the voltage and current in the capacitor is -90°. Therefore, the total current is:IT = √(IR^2 + IC^2) = √((ET / R)^2 + (ET / XC)^2) = ET * √(1 / R^2 + 1 / XC^2)The reactive power is then:Q = ET * IT * sin(θ) = ET * √(1 / R^2 + 1 / XC^2) * sin(-90°) = -ET * √(1 / R^2 + 1 / XC^2)Substituting the given values, we get:Q = -480 V * √(1 / (50 kΩ)^2 + 1 / (47 kΩ)^2) = -4.90 VARsTherefore, the reactive power is 4.90 VARs.

In an RC Parallel Circuit, ET = 480 V, R

In an RC Parallel Circuit, E_T = 480 V, R