Inductive Reactance

The capacitors and inductors are two reactive components. This implies that they react, or oppose each other, changes in electrical variables.

A capacitor opposes, for example, or reacts, to any change in voltage level. Inductors, on other hand, “react” to changes in current flow. This reactive effect has a deep relationship with the frequency. When frequency of the applied voltage to an inductor is enhanced, the inductor’s opposition to AC flow of current increases. This all happens because the energy capable of being stored in the electromagnetic field of inductor (its inductance value) stays constant, but the time period of the applied AC-voltage gets decreases. when the AC time period is decreased, few energy is required from the inductor’s electromagnetic field to oppose the voltage alternations. Take this example, when it would take 10 times the energy to oppose 100 volts for 10 seconds than it would to oppose the same voltage for 1 second.

The same rule applies with an increase in the frequency amd decrease in time period of the applied AC. We can state this basic principle by saying that the reactance of an inductor increases with an increase in frequency. This “frequency-dependent” opposition to AC flow of current through an inductor is called inductive reactance. The inductive reactance (XL), as are impedance (Z) and resistance (R), is measured in terms of ohms. The equation for calculating the value inductive reactance is, or formula of inductive reactance is

X_L = 2fL

This equation tells us that inductive reactance (measured in ohms) is equal to 6.28 (that is approximate value of 2) times frequency times the inductance value (in henrys). In illustration below the inductive reactance of the 1-henry coil having 60-hertz AC applied to it would be

X_L = 6.28 x 60 x 1 = 376.8 ohms

If the frequency of the applied ac voltage are increased to 100 Hz value, the inductive reactance of the same inductor would be

X_L = 6.28 x 100 x1 = 628 ohms

Note here that the value of inductive reactance is increased as the frequency of the applied AC goes up.