Millwright Level 1 Practice Exam

What does reverse polarity do in welding?

1. Increases the welding speed significantly

2. Leads to cooler burning and better control when position welding

3. Burns hotter and has shallower penetration

4. Reduces the amount of oxygen used in the process

The correct answer is: Leads to cooler burning and better control when position welding

Reverse polarity in welding primarily impacts the heat distribution and arc characteristics. When reverse polarity is employed, the electrode serves as the positive terminal, while the workpiece becomes the negative terminal. This configuration allows for better control and cooler burning, which is particularly beneficial in position welding. Position welding often requires precise control over the heat input to avoid warping or damaging the workpiece. By using reverse polarity, the welder can produce a softer, more controlled arc with less penetration. This means that the heat is concentrated in a more manageable manner, allowing for intricate work that might be required in tight spaces or when working on thin materials. Thus, it facilitates finesse and accuracy in the welding process. Other options touch on aspects of welding but do not accurately describe the effects of reverse polarity. For instance, suggesting that it increases welding speed or alters the amount of oxygen used are not relevant characteristics related to the polarity used in welding processes. The focus on heat and control illustrates why reverse polarity is advantageous in certain welding situations.