Which symbol is used to represent the NC contacts in a device?

The symbol used to represent normally closed (NC) contacts in a device is a circle. In electrical schematics and diagrams, a circle indicates that the contacts are closed when the device is in its unenergized state. This means that the circuit remains complete, allowing current to flow through the contact until the device is activated, which then opens the circuit.

In contrast, other symbols have specific meanings in electrical diagrams: a square typically signifies a relay or a different type of contact arrangement, a triangle may denote a particular type of device or function, and an arrow is usually used to indicate a direction or flow, such as the flow of electricity or signal. Understanding these symbols is crucial for reading and interpreting electrical diagrams accurately, ensuring the correct connections and operations within electrical systems.