EMC Questions & Answers 100% Correct!

1. What can cause stress risers? a. punch marks b. corrosion grooves c. corrosion pits d. all of the above - ANSWERSD 2. When a metal (or alloy) cools from a liquid to a solid state, the lack of molten metal to feed the shrinkage will lead to: a. pipes, voids and cavities b. sponge like appearance and hot tears c. none of the above d. both a and b - ANSWERSD 2. Which of the following is not a cause of undercutting? a. excessive amperage b. excessive travel speed c. excessive electrode diameter d. excessive restraint during welding - ANSWERSD 2. An extremely thin discontinuity that is the result of pipes or inclusions flattened and made directional by working is called: a. a stringer b. a lamination c. a seam d. a cold shut - ANSWERSB 2. In general, where can you find heat treatment cracks? a. at the center of a weld b. in areas of sudden change in thickness c. on a cast plate d. all of the above - ANSWERSB 2. Which of the following measurements indicates the smoothest surface finish? a. 250 micro inches b. 0.0002 inch c. 0.00015 inch d. 100 micro inches - ANSWERSD 2. After solidification of a casting, the internal granular structure consists of three layers: outer, intermediate and central. The central layer consists of: a. a mixture of large and small grains with random shape and orientation b. large columnar grains c. large equi-axed grains d. small equi-axed grains with random shape and orientation - ANSWERSC A cause of gas porosity is: a. welding at too low a temperature b. improper cleaning or preheating of the plates to be welded c. the use of insufficient filler metal d. restriction of the movement of the material during heating or welding - ANSWERSB