Inductive reactance

Definition

Inductive reactance is the opposition that an inductor presents to alternating current due to its inductance. It is proportional to both the frequency of the AC signal and the inductance.

5 Must Know Facts For Your Next Test

1. Inductive reactance ($X_L$) is given by the formula $X_L = 2\pi f L$, where $f$ is the frequency and $L$ is the inductance.
2. The unit of inductive reactance is ohms (Ω).
3. Inductive reactance increases with an increase in either frequency or inductance.
4. In a purely inductive circuit, the current lags behind the voltage by 90 degrees.
5. Inductive reactance causes energy to be temporarily stored in the magnetic field of the inductor.

Review Questions

• What formula is used to calculate inductive reactance?
• How does inductive reactance change with increasing frequency?
• In a purely inductive circuit, what is the phase relationship between current and voltage?

Related terms

Capacitive Reactance:

The opposition that a capacitor presents to alternating current due to its capacitance, given by $X_C = \frac{1}{2\pi f C}$.

Impedance:

The total opposition that a circuit presents to alternating current, combining resistance, inductive reactance, and capacitive reactance.

Resonant Frequency:

The frequency at which inductive reactance equals capacitive reactance in a circuit, resulting in maximum voltage or current amplitude.