What is the Difference Between Resistance and Reactance?

Resistance and reactance are two major parameters of an electric circuit element that together form the impedance (Z) of the circuit. The main differences between resistance and reactance are:

1. Definition: Resistance is the measure of opposition offered by a conductor to the flow of electric current, while reactance is the opposition to the flow of alternating current, which opposes any change in the magnitude and direction of the current.
2. Energy Dissipation: Resistance consumes active power or real power and dissipates it, meaning it cannot supply power back to the circuit. In contrast, reactance does not dissipate power; it stores it and returns it back to the circuit.
3. Circuit Types: Resistance is found in both AC and DC circuits, while reactance is specific to AC power and depends on the frequency of the current.
4. Applications: Resistance is mainly used to control the amount of electric current in an electric circuit, while reactance is used to control the sudden change in current and voltage in an AC circuit.
5. Components: Resistors introduce resistance in the path of current, whereas reactance is found in both inductors and capacitors.

In summary, resistance is the opposition to the flow of electric current, while reactance is the opposition to the change in the magnitude and direction of the current. Resistance dissipates power, while reactance stores power and returns it to the circuit. Resistance is present in both AC and DC circuits, while reactance is specific to AC circuits. Resistors are used to control the amount of electric current, while reactance is used to control sudden changes in current and voltage in AC circuits.

Comparative Table: Resistance vs Reactance

Here is a table comparing the differences between resistance and reactance: