Knob-and-tube wiring typically supports which type of electrical conductor?

Knob-and-tube wiring typically supports only ungrounded conductors. This type of wiring system, which dates back to the late 19th and early 20th centuries, consists of separate insulated conductors that are run through wooden knobs and tubes to provide support and insulation.

In this system, one conductor is usually positive (or hot), while the other is neutral. However, it's important to note that the design does not include a dedicated ground conductor. The absence of a grounding system means that knob-and-tube wiring does not provide the additional safety benefits offered by more modern wiring methods that include grounding conductors.

As a result, while knob-and-tube wiring can effectively carry electrical current, it does so without the safety assurance provided by grounded conductors, which help to prevent electrical shocks and other hazards.