Final answer:
The positive/negative LED indicates that power is on, showing current flow status. Two conducting paths are needed in a circuit for current to flow out and back, completing the circuit and allowing device operation.
Step-by-step explanation:
The purpose of a positive/negative LED is to indicate that the power is on. This is a visual indicator that shows the user whether the device is receiving power or not. Concerning two conducting paths, they are necessary because in an electrical circuit, current must have a complete path to flow. One path is for the current to flow 'out' from the power source, and the other path is for the current to return 'back' to the source, completing the circuit.
Without these two paths, known as the 'hot' and the 'neutral,' the electrical device would not operate because the circuit would not be complete, and electric current could not flow continuously. This principle is fundamental in all of electrical engineering, where every device needs a complete circuit to function properly.