What does "NC" indicate in the context of a switch?

In the context of a switch, "NC" stands for "Normally Closed." This term describes a type of switch configuration where the circuit is closed (allowing current to flow) when the switch is in its default or unactivated state. That means, under normal conditions, the switch connects the electrical path, and current can flow through it.

When the switch is actuated or operated, it opens the circuit, interrupting the flow of current. This is in contrast to a "Normally Open" switch, which remains open and does not allow current to flow under normal conditions but closes the circuit when activated. The understanding of "Normally Closed" is crucial in designing circuits, particularly in safety systems, alarm systems, and control systems where maintaining current flow under default conditions is necessary.