What does a signal light connected across a control indicate?

A signal light connected across a control serves as an indicator of the control’s status. When the control contacts are open, the circuit is incomplete, and this can be represented by the signal light not being illuminated. This typical indication provides a visual cue to the technician or operator that the control is not allowing current to flow, thereby confirming that the load is not powered.

Understanding how signal lights operate is crucial for troubleshooting and ensuring that systems are functioning properly. When a control is engaged, the contacts close, and typically the signal light indicates that the circuit is closed and the load is powered. Therefore, the correct choice focuses specifically on the state of the control contacts — open means no power is flowing, which is what the signal light reflects.

Other options, while related to electrical and control concepts, do not accurately represent the primary function of a signal light in this context. For instance, when the load is powered, you would expect the light to be illuminated, not as an indication of a problem with control contacts. A shorted socket would typically not activate a signal light in the expected manner since it points more to a fault condition. Lastly, while a neon light being operational is possible in certain diagnostics, it does not convey the same information about the control