Which statement about ladder diagrams is true?

• A. They show the physical wiring
• B. They show electrical interconnections between components
• C. They are not used in control systems
• D. They show nothing about wiring

Answer: (B)

Ladder diagrams depict how devices in a control circuit are electrically connected and how control signals flow between them. They focus on interconnections and the logic of the circuit rather than the exact physical layout of wires, mapping the relationships between components like relays, contactors, and sensors. This makes them a core tool in control systems and PLC programming, where understanding which components are connected and how power and signals travel is essential. So the true statement is that ladder diagrams show electrical interconnections between components. They do not show physical wiring routes, and they are indeed used in control systems.