When the frequency of an alternating current increases, what happens to capacitive reactance?

Capacitive reactance is defined by the formula (X_C = \frac{1}{2\pi f C}), where (X_C) is the capacitive reactance, (f) is the frequency of the alternating current, and (C) is the capacitance.

As the frequency (f) increases, the term (2\pi f) in the denominator increases, which results in a decrease in the overall value of (X_C). This means that as the frequency of the alternating current increases, the capacitive reactance decreases.

This relationship highlights the nature of capacitors in AC circuits, where higher frequencies effectively allow the capacitor to "pass" more of the current, behaving less like a barrier and more like a conductor at those frequencies. Thus, the connection between increasing frequency and decreasing capacitive reactance is well-established in electrical theory.