What is the effect of having straight polarity (DC negative)?

• A. Deep penetration
• B. No effect
• C. Increased porosity
• D. Shallow penetration

Answer: (D)

Straight polarity means the electrode is negative (DCEN). In this arrangement, more heat is concentrated at the electrode and less heat goes into the workpiece, so the weld pool is shallower and penetration is reduced. If polarity is reversed (electrode positive), more heat goes into the base metal, increasing penetration. The other options don’t fit because straight polarity does affect penetration and does not produce deeper penetration or no effect, while porosity isn’t inherently caused by polarity alone.