What is the primary difference between AC and DC current?

The primary difference between AC (Alternating Current) and DC (Direct Current) is that AC changes direction periodically, while DC flows in one direction consistently. This characteristic of AC allows it to be efficiently transmitted over long distances, which is why it is commonly used in power grids and household appliances. The periodic change of direction means that the waveform of AC can be sinusoidal or have other shapes, enabling versatility in how power is distributed.

In contrast, DC maintains a constant voltage and does not reverse direction, making it suitable for devices that require stable and consistent power, such as batteries and electronic circuits. However, the statement indicating that DC is exclusively used in medical devices is not accurate, as AC is also employed in many medical technologies. The knowledge of these fundamental differences is crucial for biomedical equipment technicians when troubleshooting or maintaining electronic devices.