Which polarity yields deeper penetration than DCEP?

• A. DCEN
• B. DCEP
• C. AC
• D. None

Answer: (A)

Heat distribution in the arc changes with polarity. With electrode negative (DCEN), most of the arc heat goes into the workpiece, giving deeper penetration. With electrode positive (DCEP), heat is drawn more into the electrode, producing shallower penetration in the base metal. AC splits heat between the electrode and workpiece, so penetration isn’t as deep as with DCEN under the same conditions. So, the polarity that yields deeper penetration than DCEP is DCEN.