In GTAW, which factor primarily sets the arc voltage?

In GTAW, which factor primarily sets the arc voltage?

• A. Arc length
• B. Gas flow rate
• C. Workpiece material
• D. Electrode angle

Answer: (A)

In GTAW, arc voltage is governed primarily by arc length—the gap between the tungsten electrode and the workpiece. The welding power supply keeps the current fixed, so the voltage adjusts to maintain that current as the arc length changes. A longer arc means a longer ionized path with higher resistance, which requires a higher voltage to keep the current flowing. A shorter arc lowers the required voltage. Shielding gas flow rate mainly affects arc stability and protection of the weld area rather than the voltage setting. The workpiece material and electrode angle influence heat transfer, penetration, and arc shape, but they don’t determine the voltage the supply must provide to sustain the arc.

In GTAW, arc voltage is governed primarily by arc length—the gap between the tungsten electrode and the workpiece. The welding power supply keeps the current fixed, so the voltage adjusts to maintain that current as the arc length changes. A longer arc means a longer ionized path with higher resistance, which requires a higher voltage to keep the current flowing. A shorter arc lowers the required voltage.

Shielding gas flow rate mainly affects arc stability and protection of the weld area rather than the voltage setting. The workpiece material and electrode angle influence heat transfer, penetration, and arc shape, but they don’t determine the voltage the supply must provide to sustain the arc.