No.	Question	A	B	C	D	Answer
15	In welding applications the term “base metal” refers to	A. low alloy steel	B. the metal to be joined	C. a pure alloy	D. the filler material	A B C D
16	The non uniform expansion and contraction of weld metal and adjacent base metals is called	A. distortion	B. tempering	C. annealing	D. ductility	A B C D
17	Which one of the following is a ferrous metal?	A. aluminum	B. copper	C. magnesium	D. mild steel	A B C D
18	Slag trapped in a weld is an example of	A. a blow hole	B. a nonmetallic inclusion	C. undercut	D. porosity	A B C D
19	Which type of metal is the best conductor of electricity?	A. aluminum	B. brass	C. copper	D. nickel	A B C D
20	What element has the most important effect on the weldability of ordinary gray cast iron	A. copper	B. carbon	C. steel	D. sulfur	A B C D
21	Holes, notches, and sharp corners in metals	A. decrease stress	B. reduce weight and add strength	C. are stress risers	D. have little effect on the loading of the part.	A B C D
22	Underbead cracking is often eliminated by	A. preheating	B. chipping	C. peening	D. backwelding	A B C D