True or False: Voltage is governed by the arc length between the electrode and the workpiece and is influenced by electrode diameter.

• A. Cannot be determined
• B. False
• C. True
• D. Both

Answer: (C)

Voltage in arc welding is controlled mainly by how far the electrode is from the workpiece—the arc length. A longer arc gap requires a higher voltage to keep the plasma ionized and the current flowing across the gap, so the arc voltage rises with arc length.

The electrode diameter affects the arc in a secondary way. A thicker electrode changes the current-carrying capability and the geometry at the tip, which influences the arc’s stability and the voltage drop near the electrode. Because the power source is usually set to a certain current, these changes in arc behavior with electrode diameter can alter the voltage you observe for a given arc length.

So the statement is true: arc length governs the voltage, and electrode diameter can influence it through its effect on current capacity and arc characteristics.