Power Pro Pre-End-of-Course Practice Test

In the context of alternating current (AC) characteristics, capacitance is the feature that is responsible for opposing any change in voltage value. When an AC voltage is applied across a capacitor, it stores energy in the form of an electric field. As the voltage changes, the capacitor resists the immediate change by drawing or releasing current, effectively smoothing out fluctuations in voltage. This characteristic of capacitance is known as reactance, which specifically addresses the capacitor's ability to impede voltage change.

This ability to oppose abrupt changes in voltage is particularly useful in various applications, such as filtering signals, where capacitors can stabilize voltage levels and reduce noise in electrical circuits. In contrast, resistance relates to opposing current regardless of the changes in voltage, inductance involves the opposition to changes in current, and impedance is a broader term that combines resistance, inductance, and capacitance effects in AC circuits. Thus, while capacitance specifically targets the behavior of voltage, the other characteristics do not focus on this aspect in the same way.