Impedance is one of the most frequently encountered fundamental components in electrical circuits. This term is very important in the analysis and design of AC circuits. As a combination of resistance, reactance and phase angle, it directly affects the efficiency and performance of electrical and electronic systems.

Impedance is denoted by the letter “Z” and is measured in ohms (Ω). This value affects the circuit’s phase difference between current and voltage, energy storage capacity and power dissipation.  This in turn determines the overall performance of the circuit. Understanding and controlling impedance is essential in many fields, from filter design to power transfer and acoustic applications.

What is Impedance?

Briefly defined, it is the resistance of an electrical circuit element or the entire circuit to alternating current (AC). It is measured in Ohm (Ω) units and defines the properties of circuit elements. This ratio is used in many applications in the field of electrical and electronics. This ratio consists of three basic components: resistance (R), capacitance (C) and inductance (L).

In order to understand impedance, knowledge of its components is necessary. Other terms related to this ratio can be explained as follows;

It is the resistance of the circuit element against current flow. This value is measured in ohms (Ω).

It is the resistance of capacitors (capacitors) and inductors (inductors) against alternating current. It can be inductive or capacitive.

It refers to the phase difference between current and voltage.

How is Impedance Calculated?

This value is found as the vector sum of resistance and reactance. The impedance formula is Z = R + jX. The “j” used here is the virtual unit. The magnitude of the impedance can be found with the Pythagoras (Pythagoras) theorem. The unit of measurement of the value is the ohm (Ω) and the phase angle is expressed in degrees (°) or radian (rad).

An impedance tester is an instrument used to measure the impedance of various electrical and electronic components, circuits and systems. Such instruments can usually measure frequency, resistance, capacitance and inductance values and analyze the real and imaginary components of impedance.


What is Impedance in Electricity?

This term can be generally defined as the resistance of an electrical circuit element to current. It has an important position in circuit analysis. In AC circuits, the impedance value is used to analyze the current, voltage and power values of the circuit. Its matching is especially important in communication, radio frequency and microwave systems. For maximum power transfer, the load impedance must be equal to the source impedance.

In electronic filter design processes, it also has an important position in the distribution and storage of energy. It is involved in many areas of life. A question about headphone impedance, “What is impedance headphones?” can be answered as a value that provides information about sound quality, power consumption and compatibility.

High impedances mean that alternating current has a harder time traveling through an electrical circuit or circuit component. It can also be understood that the circuit element has more resistance to alternating current and therefore the current flowing through the circuit is lower. To explain;

  • High impedance headphones have better sound detailing.
  • Headphones with this value draw more current and have lower power consumption.
  • High Z headphones are suitable for professional use.

Frequency Impedance Relationship

The relationship between these two terms is very important, especially in alternating current circuits. The impedance of a circuit varies depending on the applied frequency. This relationship can be examined in particular through the reactance components, capacitive reactance (Xc) and inductive reactance (XL).

What are the Differences Between Impedance and Resistance?

Resistance is the difficulty of a conductor or circuit element against direct current (DC). It is measured in Ohms (Ω). Impedance is the difficulty of a circuit element against alternating current (AC). It is also measured in Ohms (Ω), but this value is a complex number.