Parallel RL circuit Impedance Calculator
Table of Contents
A calculator to calculate the equivalent impedance of a resistor and an inductor in parallel.
The impedance is given as a complex number in standard form and
polar forms.
\( \) \( \) \( \)
Formulae for Parallel R L Circuit Impedance Used in Calculator and their Units
Let \( f \) be the frequency, in Hertz.
The angular frequency is given by
\( \omega = 2 \pi f \) , in rad/s
The inductive reactance
\( X_L = \omega L \) , in ohms \( (\Omega) \)
The impedance of the inductor \( L \) is given by
\( Z_L = j \omega L \)
Let \( Z \) be the equivalent impedance to the parallel RL circuit shown above and write it in complex form as follows
\[ \dfrac{1}{Z} = \dfrac{1}{R} + \dfrac{1}{Z_L} \]
\( Z = \dfrac{R Z_L}{R + Z_L} = \dfrac{ j R \omega L }{R+j \omega L } = \dfrac{1}{\dfrac{1}{R} - j \dfrac{1}{\omega L}} \)
The formulae for the modulus \( |Z| \) and argument (or phase) \( \theta \) of \( Z \) are given by
Modulus: \( |Z| = \dfrac{1}{\sqrt{ \dfrac{1}{r^2} + \dfrac{1}{\omega^2 L^2}}} \) in ohms \( (\Omega) \)
Argument (Phase): \( \theta = \arctan \left( \dfrac{ R }{\omega L} \right) \) in radians or degrees
Use of the calculator
Enter the resistance, the capacitance and the frequency as positive real numbers with the given units then press "calculate".
Results of Calculations
More References and links
AC Circuits Calculators and Solvers
Complex Numbers - Basic Operations
Complex Numbers in Exponential Form
Complex Numbers in Polar Form
Convert a Complex Number to Polar and Exponential Forms Calculator
Engineering Mathematics with Examples and Solutions