In a properly functioning circuit, what should the ohm reading be across an open limit switch?

In a properly functioning circuit, an open limit switch is designed to break the current flow in the circuit when it is not activated. As a result, when measuring the resistance across an open limit switch, the reading should indicate infinity ohms. This essentially reflects an open circuit condition, meaning no electrical continuity is present because the switch is open and not allowing electricity to flow. Thus, the meter will show a maximum resistance value, which is interpreted as infinite resistance.

The other options reflect scenarios that do not correspond to the state of an open limit switch. A reading of zero ohms would indicate a closed circuit or a shorted switch, which is not the case here. Values like twenty-four ohms or one hundred ohms would suggest incomplete closure or a fault within the switch, as these readings signify some level of current flow still available that contradicts the expected behavior of an open limit switch.