In a ladder diagram, what does a rung represent?

• A. A mechanical rung that physically connects parts.
• B. A live wire path.
• C. The control path that completes a circuit when the rung conditions are satisfied.
• D. A coil symbol.

Answer: (C)

In ladder diagrams, a rung is the control path that connects the left power rail to the right side and represents the set of conditions that must be met to energize an output. When all the devices on that rung (such as normally open or normally closed contacts) are in their true state, current can flow through the rung and energize the output coil at the end of the rung. It’s a logical pathway, not a physical rung or just a live wire, and the coil symbol at the end is the actuator that responds when the rung is satisfied.