Which component is commonly represented on a one line diagram?

A one line diagram, also known as a single line diagram, provides a simplified representation of an electrical system, primarily focusing on the main components and their interconnections rather than the intricate details of individual elements. Transformers are integral parts of electrical systems because they modify voltage levels for efficient power distribution. In a one line diagram, transformers are depicted to show how the power is transformed from one voltage level to another, allowing for a clear understanding of the system's overall operation and layout.

While light bulbs, resistors, and switches can be critical components within an electrical system, they are typically not represented in detail on a one line diagram. Instead, a one line diagram emphasizes larger components that have significant effects on the system's functionality, like transformers, which play a key role in ensuring that electricity is transmitted effectively across long distances or utilized at appropriate voltages.