Ham Amateur Radio Technician Practice Exam 2026 – The Complete All-in-One Guide to Exam Success

An inductor's behavior in an alternating current (AC) circuit is fundamentally linked to its property of inductance, which opposes changes in current. Reactance is the measure of how much an inductor resists the flow of AC, and it is affected by the frequency of the AC signal.

As frequency increases, the reactance of the inductor also increases. Reactance (XL) is calculated using the formula XL = 2πfL, where f is the frequency and L is the inductance. Therefore, when the frequency (f) rises, the value of reactance (XL) directly increases, leading to greater opposition to the AC current. This means the inductor will impede the flow of current more as the frequency goes up.

This relationship is fundamental in many RF (radio frequency) applications and helps in creating filters, tuning circuits, and shaping waveforms in AC systems. Thus, it is clear why the correct answer highlights the direct correlation between frequency and reactance in inductors.