NOT one of the three main sub-systems of the Electrical System?

• A. Regulator
• B. Supply
• C. Distribution
• D. Consumers

Answer: (A)

The main idea here is distinguishing between broad subsystems and individual control components within an electrical system. The three broad sub-systems are the supply (source of power), the distribution (carrying power to where it’s needed), and the consumers (the devices or loads using the electricity). A regulator, on the other hand, is a control device that keeps voltage or current within safe or desired levels. It functions inside the system to maintain stability, but it isn’t one of the three broad sub-systems itself. So the regulator is not a main sub-system, while supply, distribution, and consumers are.