Which voltage is measured at the output terminals of the power source during welding?

• A. Open circuit voltage
• B. Arc Voltage
• C. Load voltage
• D. None of the above

Answer: (C)

When welding, current flows through the circuit, so the voltage you measure at the power source’s output terminals is the voltage delivered to the load—the arc and workpiece. This is known as the load voltage. Open circuit voltage is what you’d measure with no arc (no current) in the circuit, while arc voltage refers specifically to the voltage drop across the arc itself; under welding conditions, the terminal voltage during operation is the load voltage. Therefore, the measurement during welding corresponds to the load voltage.