183 8. The work angle for a fi llet weld on a T-joint is _____. A. 10° B. 20° C. 30° D. 45° 9. The _____ pass is the fi rst and most important in a butt joint. A. cover B. root C. fi llet D. hot 10. Which of the following is the best defi nition of undercut? A. Visual pockets on the surface of the weld face. B. Foreign material trapped inside a completed weld. C. Base metal melted at the toe of a weld but not fi lled with fi ller metal. D. Weld toe is not fused into the base metal. Apply and Analyze 1. _____ are worn under the welding helmet to protect from reflected arc rays. 2. The _____ is the distance between the electrode and the base metal. 3. Arc blow is the result of a(n) _____ around the wire or electrode. 4. What current is recommended in Figure 11-9 for a 3/32″ (2.4 mm) E6013 electrode? 5. What is the recommended arc length for a 5/32″ electrode? 6. Right-handed welders usually start from the _____ side of the weld joint. Left-handed welders start from the other side. 7. The electrode is typically tilted 20° in the direction of travel. This is called backhand welding or a(n) _____ travel angel. 8. What is the cause of a weld bead that is rough with a lot of spatter? It may also cause poor penetration and undercutting at the weld toes. 9. What is the shape of the weld pool when making a fi llet weld? 10. How far forward is an electrode moved when using the whip and pause technique? STEM Connections 1. Math. Investigate the mathematical principles involved in determining the angle of the electrode from perpendicular and from the surface. Refer to Figure 12-9 as needed in your investigation. Notice that the two angles in the side view of the fi gure, when added, equal 90°. What name is given to two angles that equal 90°? How could you use this principle in a practical way when determining the proper electrode travel and work angles? 2. Technology. Conduct research to fi nd out more about fi re-resistant clothing. Write a report comparing and contrasting the different methods of making clothing fi re-resistant. Which methods are generally used for cloth welding jackets? Why? 3. Science. Conduct research to fi nd out more about the principles of electromagnetism. Create a poster to illustrate how electromagnetism affects SMAW welding when AC polarity is used and when DC polarity is used. Curricular Connections 1. Critical Thinking. A welder who has been assigned to weld 3/16″ plate is given a new assignment to weld plates of 9/16″ carbon steel. The resulting welds must have full penetration. The welder’s fi rst inclination is to use a square groove butt joint, which he has mastered and welded on 3/16″ plate with great success. Why is this a bad choice? What type of joint would you recommend, and why? 2. Language Arts. Conduct research to fi nd out more about iron powder electrodes. Write a technical report explaining when they are most useful and describing their advantages and disadvantages. Copyright Goodheart-Willcox Co., Inc.