Meters and troubleshootingQuestion 542 of 1506

A switch in a working series circuit is opened. What voltage appears across the open contacts?

  1. Zero volts
  2. Half the source voltage
  3. The full source voltage
  4. The voltage of the load
Show answer

Correct answer: The full source voltage

With no current, all the source voltage appears across the break.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 1.4: Voltage and Current

Practice meters and troubleshooting

Questions last reviewed: 18 October 2026