In plasma arc cutting, which supplies part of the cutting heat?

• A. Acetylene
• B. Electricity
• C. Water
• D. Natural gas

Answer: (B)

In plasma arc cutting, the heat comes from the electric arc itself. Electricity passes through the plasma torch to ionize the gas into a hot plasma jet that conducts the heat to the workpiece, melting or vaporizing the metal. The cutting gas mainly forms and sustains the plasma and helps blow away the molten metal; it isn’t the primary heat source. Acetylene and natural gas are fuels used in oxy-fuel cutting, not plasma cutting, and water is typically used for cooling rather than supplying cutting heat.