Designation of total impedance Z and its components for AC circuit. In example circuit impedance which is seen from power supply terminals will be calculated. Circuit is built with two inductivities, three resistors and capacitor. Impedances of every part in circuit is known. Circuit has mixed connections, parallel and serial . Relation between impedance Z and admittance Y will be applied → Y=1/Z. Admittance is usually used to calculate impedance of parallel connection between parts.