assume that we have a relay:
what will happen if we connected the relay coil with the normally closed contact (series connection)of the relay then we applied electricity through the normally closed contact to the coil ?
The NC contacts are ‘made’, so when the coil is energized, the contacts open. As the contacts open, the coil de-energizes, so the contacts begin to close, but as the contacts close and are ‘made’ again, the coil re-energizes.
The relay will chatter continuously (and sound like a buzzer), cycling between on and off until it destroys itself in a short time.
This relay is not wired for functionality, it is miswired (Power through the NC contacts driving the coil).
In a functional circuit, when an external circuit drives the coil, then the coil’s NC contact will ‘invert’ the state of the coil as poster automate suggests. Coil = ON or logic 1, NC contacts = Open/Off or logic 0.