A latching relay is a relay that requires a short pulse to energize the relay.

• A. Digital output
• B. Pseudopoint
• C. Latching relay
• D. Accumulator

Answer: (C)

A latching relay operates by changing state with a brief input pulse and then staying in that state without needing continuous power. This bistable behavior means a momentary energize toggles the contacts, and the relay “remembers” the position until another short pulse is applied to switch it back. This is often achieved with two coils (set and reset) or a single coil driven in opposite directions. Because it holds its state without power, it’s energy-efficient and useful when you only want a quick trigger to switch a circuit.

Other options don’t describe a relay: a digital output is a signalling type, not a device that latches; a pseudopoint isn’t a standard term for this context; an accumulator is a memory element used to store a value, not a switching device.