Courses
Courses for Kids
Free study material
Offline Centres
More

Reactance vs Impedance: Differentiate between Reactance and Impedance Reaction

ffImage
Last updated date: 24th Feb 2024
Total views: 81.9k
Views today: 2.81k
hightlight icon
highlight icon
highlight icon
share icon
copy icon

Introduction: Difference between Reactance and Impedance

In the world of electrical circuits, reactance and impedance play vital roles. Reactance refers to the opposition encountered by inductors and capacitors when connected to AC. On the other hand, impedance encompasses both resistance and reactance, offering a holistic measurement of opposition in AC circuits. By differentiating between reactance and impedance reactions, engineers and technicians can better analyse and optimise the performance of electrical systems.


Reactance:

Reactance measures the opposition faced by inductors and capacitors to the flow of alternating current. It is denoted by the symbol 'XL' and is measured in ohms (Ω). Reactance includes inductive reactance (XL) and capacitive reactance (XC). Inductive reactance increases with frequency, while capacitive reactance decreases with frequency.


Impedance:

Impedance represents the total opposition faced by electrical components in an AC circuit. It is denoted by the symbol 'Z' and is measured in ohms (Ω). Impedance combines resistance and reactance. Resistance (R) refers to the opposition offered by a circuit element to the flow of current, and it is measured in ohms. Hence, impedance encompasses both resistance and reactance.


Difference between Reactance and Impedance:

This section deals with Reactance vs Impedance. The primary difference lies in their composition and purpose within electrical circuits. Reactance solely focuses on the opposition offered by inductors and capacitors in an AC circuit. It does not include resistance. On the other hand, impedance encompasses both resistance and reactance, providing a more comprehensive measurement of opposition. In other words, impedance is the total opposition faced by electrical components in an AC circuit.


The table describes the difference between Reactance and Impedance:


Reactance

Impedance

Reactance refers to the opposition faced by inductors and capacitors in an AC circuit. Reactance does not include resistance.

Impedance represents the total opposition faced by electrical components in an AC circuit. Impedance includes both resistance and reactance.

It is solely concerned with the opposition offered by inductors and capacitors in an AC circuit.

In this, the opposition is offered by resistors, inductors, and capacitors in an AC circuit.

Inductive reactance (XL) is calculated using the formula XL = 2πfL.
Where f is the frequency of alternating current and L is the inductance. Capacitive reactance (XC) is calculated using $X_C=\frac{1}{2πfC}$, where C is the capacitance.

Impedance (Z) is calculated using the formula $Z =\sqrt(R^2 + (X_L - X_C)^2)$, where R represents resistance, XL is the inductive reactance, and XC is the capacitive reactance.

Reactance has only magnitude, which represents the amount of opposition faced by inductors and capacitors.

Impedance has both magnitude and phase. The magnitude represents the total opposition, while the phase accounts for the shift between the voltage and current waveforms.

It is a component of impedance, focusing solely on the opposition offered by inductors and capacitors.

It includes both reactance and resistance, providing a comprehensive measure of total opposition in an AC circuit.


Reactance and Impedance Reactions:

The fundamental question that often arises is: What is reactance and impedance reactions? These are important concepts in the field of electrical circuits, particularly when dealing with alternating current (AC). While both terms are related to the opposition faced by electrical components in an AC circuit, there are key differences between them. These reactions provide insights into how inductors, capacitors, and resistors behave in electrical systems, enabling us to optimize and design circuits more efficiently.


Reactance Reactions:

  • Inductive Reactance (XL): Inductive reactance is the opposition encountered by inductors in an AC circuit. It arises from the behavior of inductors, which store energy in a magnetic field. Inductive reactance increases with higher frequencies of AC.

  • Capacitive Reactance (XC): Capacitive reactance is the opposition encountered by capacitors in an AC circuit. It arises from the behavior of capacitors, which store energy in an electric field. Capacitive reactance decreases with higher frequencies of AC.


Impedance Reactions:

Impedance represents the overall opposition faced by electrical components in an AC circuit. It combines resistance, inductive reactance, and capacitive reactance. Impedance is denoted by the symbol 'Z' and is measured in ohms (Ω). It determines the total opposition to the flow of AC current in a circuit.


Impedance is calculated using the formula $Z = √(R^2 + (X_L - X_C)^2)$, where R represents resistance, XL represents inductive reactance, and XC represents capacitive reactance. By calculating impedance, engineers can assess the combined effect of resistance and reactance on the flow of AC current in a circuit.


In AC circuits, reactance and impedance reactions examples are such as an inductive reactance increases with frequency, causing an inductor to impede current more at higher frequencies. On the other hand, capacitive reactance decreases with frequency, allowing a capacitor to pass more current at higher frequencies. When considering impedance, the combination of resistance, inductive reactance, and capacitive reactance determines the overall opposition to current flow in the circuit


Summary:

Reactance and impedance are fundamental concepts in AC circuits. Reactance represents the opposition faced by inductors and capacitors to the flow of AC, while impedance combines resistance and reactance to provide a comprehensive measure of opposition.


Reactance reactions include inductive reactance and capacitive reactance, while impedance combines resistance, inductive reactance, and capacitive reactance. Understanding these concepts is essential for designing and analyzing electrical circuits, enabling engineers to optimize circuit performance, prevent issues, and achieve desired circuit characteristics.

FAQs on Reactance vs Impedance: Differentiate between Reactance and Impedance Reaction

1. Can reactance or impedance be negative?

Reactance and impedance can have negative values. Negative reactance or impedance arises when the capacitive reactance is greater than the inductive reactance in a circuit. It indicates a phase shift between the current and voltage waveforms.

2. Can impedance exist without reactance?

No, impedance always incorporates both resistance and reactance. Even in circuits where there is no reactive element (inductor or capacitor), resistance contributes to the overall opposition to AC, thus forming the impedance.

3. How do reactance and impedance impact power usage in circuits?

Reactance and impedance introduce phase shifts between voltage and current, causing power consumption to vary based on the reactive components present in the circuit.