With a constant voltage power source, arc voltage changes only if the arc length and amperage increase or decrease?

• A. True
• B. False
• C. Not sure
• D. Sometimes

Answer: (B)

With a constant voltage power source, the voltage across the arc is held near the set value. If you lengthen the arc, the arc’s resistance goes up and the current drops, but the supply maintains the same arc voltage. If you shorten the arc, current rises but the arc voltage remains roughly the same. So arc voltage does not depend on arc length or the current in the way the statement suggests; it’s the current that changes while the voltage stays clamped by the power source. That’s why the statement is false.