Parallel RL Circuit Impedance Calculator

Calculate the equivalent impedance in complex and polar forms

About This Calculator

This calculator determines the equivalent impedance of a resistor and inductor connected in parallel in an AC circuit. The result is presented as a complex number in both standard and polar forms, giving you complete information about the impedance magnitude and phase angle.

Parallel RL circuit diagram showing a resistor R and inductor L connected in parallel

Formulas Used in Calculations

For a parallel RL circuit, where:

The impedance of the inductor is given by:

\(Z_L = j\omega L\)

The equivalent impedance \(Z\) of the parallel RL circuit is:

\(\dfrac{1}{Z} = \dfrac{1}{R} + \dfrac{1}{Z_L}\)

Which simplifies to:

\(Z = \dfrac{R Z_L}{R + Z_L} = \dfrac{j R \omega L}{R + j\omega L} = \dfrac{1}{\dfrac{1}{R} - j\dfrac{1}{\omega L}}\)

The magnitude (modulus) and phase angle of the impedance are:

Modulus: \(|Z| = \dfrac{1}{\sqrt{\dfrac{1}{R^2} + \dfrac{1}{\omega^2 L^2}}}\) in ohms (Ω)

Phase angle: \(\theta = \arctan\left(\dfrac{R}{\omega L}\right)\) in radians or degrees

Parallel RL Circuit Calculator

Enter the values for resistance, inductance, and frequency to calculate the impedance:

Results

Inductive Reactance (XL):

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Impedance (Complex Form):

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Impedance Magnitude (|Z|):

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Phase Angle (radians):

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Phase Angle (degrees):

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References & Further Reading