Electrical circuit is built with three passive parts, resistor R1=2[Ω], capacitor C1=2[μF] and inductivity L1=100[mH]. All parts in circuit are connected in parallel. Circuit is supplied with voltage U. Voltage's rms value is 230[VAC]. Voltage has frequency f=50[Hz]. Subject of example is calculation of current I, which flows through circuit. In example total impedance Z will be calculated. Ohm's law for AC circuits will be applied to calculate current I → I=U/Z. All calculations in example are made with application of complex numbers.