Final answer:
The correct power source required for GMAW (MIG) welding is a DC power source. The DC voltage aids in creating a stable arc essential for consistent welds, and while other power sources exist, they are not commonly used for this process.
Step-by-step explanation:
The GMAW (Gas Metal Arc Welding) process, also commonly referred to as MIG (Metal Inert Gas) welding, requires a constant DC (Direct Current) power source. The power source supplies a continuous and stable DC voltage that helps create a steady arc and consistent welding performance. In GMAW/MIG welding, it's important to have the right polarity, which is typically DC electrode positive (DCEP). This means that the electrode, which is the wire in this case, is connected to the positive terminal, providing deeper penetration of the metal being welded.
Option 1, AC power source, is not typically used for MIG welding because it can lead to unstable arc behavior. Option 3, a battery power source, might be used in portable welding equipment for field repairs but is not the primary power source for typical GMAW processes. Option 4, a solar power source, can hypothetically be used if converted into appropriate DC power, but it is not a standard or common power source for MIG welding tasks.
Therefore, the correct answer to the question is: 2) DC power source.