Arc welding polarity — definition of straight polarity (DCEN) In manual metal arc (SMAW) with direct current, the setup is called “straight polarity” when which connection is used?

Introduction / Context:
Polarity in DC arc welding affects heat distribution between the electrode and the work. Correct selection influences penetration, spatter, and electrode performance. The two basic options are straight polarity (DCEN) and reverse polarity (DCEP).

Given Data / Assumptions:

• SMAW setup with a DC power source.
• Electrode holder carries the consumable electrode; the work clamp connects to the workpiece.
• Names: DCEN = direct current electrode negative (straight); DCEP = direct current electrode positive (reverse).

Concept / Approach:
In DCEN, electrons flow from the electrode (negative) to the work (positive). About two-thirds of the heat is generated at the positive side due to electron impact. Therefore, DCEN concentrates more heat in the workpiece, yielding deeper penetration and cooler electrode tip. This configuration is traditionally called straight polarity. Conversely, DCEP (reverse polarity) focuses more heat at the electrode and is beneficial for certain coatings and cleaning actions in processes like GTAW on aluminium.

Step-by-Step Solution:
Translate terminology: “straight polarity” = “electrode negative”.Apply to leads: electrode holder to negative; work to positive.Select the matching option.

Verification / Alternative check:
Welding textbooks and power source panels often label terminals EN (electrode negative) and EP (electrode positive), confirming the definition.

Why Other Options Are Wrong:

• Option (b) describes reverse polarity (DCEP).
• Options (c) and (d) misuse “earth” and do not define DCEN correctly.
• Option (e) describes AC, not DC straight polarity.

Common Pitfalls:
Memorise: Straight = Electrode Negative (S → EN). Reverse = Electrode Positive.

Final Answer:
work connected to positive and electrode holder to negative