What should the voltage reading across an open switch in an energized electrical circuit show?

When a switch in an energized electrical circuit is open, it means that there is a break in the circuit, preventing the flow of current. However, because the switch is part of the circuit, the voltage potential from one side of the switch to the other is present. The correct answer indicates that the voltage reading across an open switch will show the full applied voltage.

In this scenario, since the circuit is energized, the voltage that is supplied to the circuit is still present on the side of the switch that is connected to the power source. Therefore, if you measure the voltage across the switch, you should observe the full applied voltage, reflecting the potential difference created by the voltage source. This situation occurs because there is no load connected to draw current; the open switch itself does not consume or drop voltage.

Understanding this is crucial for diagnosing electrical issues, ensuring safe practices when working on energized circuits, and knowing how to interpret voltage readings effectively.