What characterizes alternating current (AC)?

Alternating current (AC) is defined by its characteristic of changing both in magnitude and in direction over time. This fluctuation allows for the efficient transmission of electricity over long distances and is the standard form of electrical power used in homes and industries.

In AC, the voltage alternates in polarity and the current changes direction periodically, typically in a sinusoidal waveform. This is in contrast to direct current (DC), where the flow of electrons is steady and unidirectional.

The property of AC allows it to be transformed easily to different voltages using transformers, making it versatile for various applications, such as powering homes, businesses, and machinery. This adaptability and the ability to easily manipulate its characteristics are some of the reasons AC is preferred for most power systems today.