Which of the following is not an advantage of an AC arc welding machine?

Which of the following is not an advantage of an AC arc welding machine?

• A. The machine is relatively inexpensive
• B. Out of position welds have less weld spatter
• C. Welds have moderate penetration
• D. High AC currents can be used with large diameter electrodes

Answer: (B)

AC arc welding uses alternating current, which means the arc polarity reverses rapidly. This setup is generally inexpensive to build, can deliver the high currents needed for welding with large-diameter electrodes, and yields a moderate level of penetration that fits many common joint configurations. The idea that out-of-position welds have less weld spatter with an AC machine isn’t accurate because the rapid polarity changes can make the arc less stable in some positions, often increasing spatter rather than reducing it. So, the statement about less spatter in out-of-position welds is not an advantage of an AC arc welding machine, while the other points describe typical advantages.

AC arc welding uses alternating current, which means the arc polarity reverses rapidly. This setup is generally inexpensive to build, can deliver the high currents needed for welding with large-diameter electrodes, and yields a moderate level of penetration that fits many common joint configurations. The idea that out-of-position welds have less weld spatter with an AC machine isn’t accurate because the rapid polarity changes can make the arc less stable in some positions, often increasing spatter rather than reducing it. So, the statement about less spatter in out-of-position welds is not an advantage of an AC arc welding machine, while the other points describe typical advantages.