Which statement describes the distribution of arc heat in DCEP?

Which statement describes the distribution of arc heat in DCEP?

• A. Plate receives 2/3, electrode 1/3
• B. Plate receives 1/3, electrode 2/3
• C. Plate and electrode share heat equally
• D. All heat goes to the gas

Answer: (B)

In DCEP, the electrode is the positive pole and the workpiece is negative, which shifts most of the arc heat into the electrode. The tungsten tip and the arc near it absorb about two-thirds of the heat, while the plate (workpiece) receives roughly one-third. The shielding gas is heated too, but it doesn’t take the majority of the arc heat. This explains why heat input to the workpiece is lower with DCEP than to the electrode. The other distributions don’t match how the energy concentrates with positive polarity, so the plate receiving about one-third and the electrode about two-thirds is the best description.

In DCEP, the electrode is the positive pole and the workpiece is negative, which shifts most of the arc heat into the electrode. The tungsten tip and the arc near it absorb about two-thirds of the heat, while the plate (workpiece) receives roughly one-third. The shielding gas is heated too, but it doesn’t take the majority of the arc heat. This explains why heat input to the workpiece is lower with DCEP than to the electrode. The other distributions don’t match how the energy concentrates with positive polarity, so the plate receiving about one-third and the electrode about two-thirds is the best description.