Plasma arc cutting process is best described as which of the following?

• A. It uses a chemical reaction between fuel and oxygen.
• B. It relies on a water jet to cut metal.
• C. It uses an electrical arc to ionize gas and cut metal.
• D. It relies on a mechanical saw blade.

Answer: (C)

Plasma arc cutting relies on an electrical arc to ionize a gas into plasma, which then becomes a conductive jet that melts and blows away metal along a cut line. The arc heats the workpiece to very high temperatures, and the flowing plasma jet carries melted metal away, producing a clean cut. This process uses an electric current through a gas to form plasma, distinguishing it from other cutting methods. The other descriptions don’t fit: oxy-fuel cutting relies on a chemical reaction between fuel and oxygen, water jet cutting uses a high-pressure stream of water (often with abrasive), and mechanical sawing uses a blade to physically cut.