What does AC stand for and how does it differ from DC?

AC stands for Alternating Current, and it is characterized by the periodic reversal of direction of the flow of electric charge. This means that the voltage and current in an AC system oscillate over time, typically following a sinusoidal waveform. This behavior allows AC to be efficiently transmitted over long distances, making it the preferred form of electricity for power distribution systems.

In contrast to AC, Direct Current (DC) flows consistently in one direction and maintains a constant voltage level. Various devices, such as batteries and electronic circuits, utilize DC, but it is less suited for long-distance transmission due to greater energy loss through resistance.

The other options provided do not accurately represent the nature of AC or DC. The definition of "amplified current" and "applied current" is not standard in electrical terminology, and those descriptions do not reflect the standard characteristics of alternating or direct current. Understanding the distinction between AC and DC is crucial for anyone involved in electrical theory and applications, as each type of current has its own set of practical applications, advantages, and disadvantages.