What does NO stand for in relay terminology?

What does NO stand for in relay terminology?

• A. Normally Open
• B. Normally Closed
• C. No Connection
• D. Neutral Output

Answer: (A)

NO stands for Normally Open. In relay terminology, a contact labeled as normally open is open (no electrical connection) when the relay coil is not energized. When the coil is energized, the contact closes, allowing current to flow from the common terminal to the NO contact. This is useful when you want a circuit to turn on only after a control signal activates the relay. By contrast, a normally closed contact is closed when the coil is de-energized and opens when energized, which is the opposite behavior. The other terms listed aren’t standard for relay contact states — they don’t describe the default on/off behavior of the contact itself.

NO stands for Normally Open. In relay terminology, a contact labeled as normally open is open (no electrical connection) when the relay coil is not energized. When the coil is energized, the contact closes, allowing current to flow from the common terminal to the NO contact. This is useful when you want a circuit to turn on only after a control signal activates the relay.

By contrast, a normally closed contact is closed when the coil is de-energized and opens when energized, which is the opposite behavior. The other terms listed aren’t standard for relay contact states — they don’t describe the default on/off behavior of the contact itself.