What is the difference between AC and DC electrical systems?

The distinction between alternating current (AC) and direct current (DC) centers on the direction of flow of electrical charge. AC periodically reverses direction, meaning that the flow of electric charge alternates back and forth within the circuit, which is commonly seen in power systems that deliver electricity to homes and businesses. This alternating nature allows for efficient transmission over long distances, making AC suitable for widespread distribution.

In contrast, DC flows in one direction only, delivering a constant voltage and current. This characteristic is commonly utilized in low-voltage applications such as batteries, electronic devices, and circuits where stable voltage is essential. Understanding this fundamental difference is crucial for anyone working in the field of electrical engineering, as it influences the choice of electrical systems for varying applications.

While other choices may touch on aspects related to AC and DC systems, they do not accurately represent the core definition of each type of current as it relates specifically to its flow direction.