Which logical function is associated with a rung that has a normally closed contact on an input device?

A rung that includes a normally closed contact on an input device is associated with the NOT logical function. In a control circuit, a normally closed contact means that the circuit is completed (or the contact is closed) when the input device is not energized. This means that the output will be activated as long as the input is inactive.

In terms of logic, the NOT function inverts the input state. When the normally closed contact is intact, the output is true, and when the input device is activated (which opens the normally closed contact), the output becomes false. This behavior exemplifies the function of NOT, as it produces the opposite output to the state of the input.

The other functions like NOR, AND, and OR behave differently with their own set of rules and requirements concerning input states and necessary conditions for activation. Understanding these concepts of input conditions and their corresponding logical outcomes is crucial in electrical control circuits.