Which statement is true about DCEN in GTAW?

Which statement is true about DCEN in GTAW?

• A. Heat balance in arc is 70% at the work end and 30% at the electrode end
• B. Penetration is shallow and wide
• C. Electrode capacity is poor
• D. It uses positive polarity

Answer: (A)

In GTAW, polarity controls where most of the arc heat goes. Direct Current Electrode Negative means the electrode is negative and the workpiece is positive. This setup pushes more heat into the workpiece, which produces deeper penetration and less wear on the tungsten electrode. A common way to summarize this is that about 70% of the heat is delivered to the workpiece and about 30% to the electrode. That aligns with the statement you’re evaluating, making it the true one. The other ideas don’t fit this polarity. Using DCEN is not positive polarity—that would be DC electrode positive. With DCEN, heat is not primarily at the electrode, so the notion of shallow and wide penetration isn’t correct; DCEN favors deeper penetration, not shallower. Also, “electrode capacity” isn’t a standard way to describe DCEN behavior in GTAW.

In GTAW, polarity controls where most of the arc heat goes. Direct Current Electrode Negative means the electrode is negative and the workpiece is positive. This setup pushes more heat into the workpiece, which produces deeper penetration and less wear on the tungsten electrode. A common way to summarize this is that about 70% of the heat is delivered to the workpiece and about 30% to the electrode. That aligns with the statement you’re evaluating, making it the true one.

The other ideas don’t fit this polarity. Using DCEN is not positive polarity—that would be DC electrode positive. With DCEN, heat is not primarily at the electrode, so the notion of shallow and wide penetration isn’t correct; DCEN favors deeper penetration, not shallower. Also, “electrode capacity” isn’t a standard way to describe DCEN behavior in GTAW.