Chapter 14 Knowledge Check

Chapter 14

Quiz yourself using the following chapter review questions to check how well you can recall the material.

Review Questions

1. Tungsten Inert Gas welding was originally modified into a cutting process to cut                          .
2. Which one of the following  is a main advantage of Plasma Arc Cutting (PAC)?
   1. Low cost.
   2. Slow cutting speed.
   3. Fast, high quality cutting.
   4. Requires high preparation work.
3. True or False: PAC requires an electrical power source and compressed air.
4.                        is considered to be a fourth state of matter, along with solid, liquid, or gas.
5. Which of the following is NOT a typical use for handheld Plasma Arc Cutting?
   1. Vehicle repair.
   2. Tank fabrication.
   3. Ornamental fabrication.
   4. Heavy equipment manufacturing.
6. What is the main function of the power source in a plasma arc cutting system?
   1. To focus the plasma.
   2. To act as a CNC controller.
   3. To regulate the amperage.
   4. To provide direct current for the arc and control the flow of gas or compressed air.
7. What should you always wear to protect your eyes while plasma arc cutting?
   1. Safety goggles.
   2. Welding helmet with the appropriate shade.
   3. Glasses with UV protection.
   4. Face shield.
8. True or False: Testing on scrap material helps troubleshoot settings before cutting your actual material.
9. True or False: If you don’t cut all the way through the material, you should decrease the amperage.
10. How can you avoid electrical shock while using plasma arc cutting equipment?
    1. Only use the equipment in dry conditions.
    2. Use rubber surgical gloves at all times.
    3. Never use extension cords.
    4. Avoid grounding the machine chassis to earth.

Answer Key

1. Stainless steel. Stainless steel is not easily cut with oxy-fuel due to its oxide layer. PAC was developed specifically for cutting stainless steel.
2. Fast, high quality cutting. One reason PAC is popular is because it quickly produces high quality cuts.
3. True. The need for an electrical power and compressed air limit PAC’s portability.
4. Plasma. Plasma is considered a fourth state of matter largely because it does not fit into the characteristics of other states of being.
5. Heavy equipment manufacturing. Heavier materials that need to be cut in large quantities are typically mechanized or robotic.
6. To provide direct current for the arc and control the flow of gas or compressed air. The power source provides the DC for the arc, and controls the cutting air or gas.
7. Welding helmet with the appropriate shade. Like other arc processes, PAC produces UV light that can permanently damage eyes or even cause blindness. Proper shade is necessary for protection.
8. True. Similar to welding, you should always test your machine on a piece of scrap to verify proper function and settings.
9. False. Not completely cutting through the metal can be caused by insufficient air/gas pressure, travelling too fast, or not having enough current/electrical energy.
10. Only use the equipment in dry conditions. Like all electrical equipment, avoid getting PAC equipment wet, and avoid handling the equipment with wet clothes or gloves.