What is the primary distinction between a single-phase and a three-phase electrical system?

The primary distinction between a single-phase and a three-phase electrical system lies in the characteristics of the alternating current waveforms they utilize. A single-phase system uses one alternating current waveform, which typically delivers power to smaller residential loads and appliances. This means that the electrical supply alternates in one cycle, resulting in a sinusoidal wave that varies in voltage, which can lead to inefficiencies for larger loads or complex circuits due to the fluctuation.

In contrast, a three-phase system comprises three alternating current waveforms that are out of phase with each other by 120 degrees. This structure provides a more stable and continuous supply of power that can support larger electrical loads and is commonly used in industrial settings due to its efficiency. The three-phase system is more effective in transmitting electricity over long distances and is capable of running heavy machinery more smoothly.

The other options do not accurately represent the differences between the two systems. A three-phase system utilizes three alternating current waveforms rather than two, and it is generally more efficient than a single-phase system. Single-phase systems are not suited for handling larger loads effectively; that capacity is a hallmark of three-phase systems.