MECH 321 56 Multiple Choice -True/False Answer Sheet

MECH 321 56 Multiple Choice -True/False Answer Sheet 2010 A Surname, given names: Student Number: e number Detach this sheet from the answer book to make your task easier but ensure that your name and student ID are on this page as well as on your exam paper. For questions (1-40), fill in, or put a distinct X in the box containing the letter of the "best" answer to that question, E.g. If you want answer (b) fill in the box containing (b) as indicated. 1 a 8 C d e The numbers refer to the question numbers on the exam paper. Fill in only one box per question.-A line with two or more responses will be treated as blank. Q Q 1 -a b c d 16 F 2 b C d e 17 F 3 a b C d 18 F X 4 a C d e 19 T 5 a b e 20 T 6 b d e 21 F 7 a b C e 22 T 8 a b C d 23 T و b c d P 24 F X 10 a C d e 25 F 11 a b C e 26 T 12 a C d e 27 F 13 a b C e 28 T 14 a b C e 29 15 a b C e 30 2/30 C) 18.7 MN d) 34.1 MN e) 187 MN A 7. A single crystal of a metal is subjected to a tensile stress. The critical resolved shear stress, ta on the most favourable slip system (for which ф = 60° and λ = 35°) is 7.2MPa.What is the magnitude of the tensile-stress that willcause yielding in this crystal? Teess = 7.2MPa 8. 9. a) 2.95 MPa b) 3.6 MPа c) 14.4 MPa d) 17.58 MPa e) 29.5 MPa σ = 7.2 X10Pa = 17-58πρα Τr= σαςλωςΦ (cos35)(cOSGO) Cold rolling or forming causes an increase in hardness. The reason for this is that: