1. Is it possible for two screw dislocations of opposite sign to annihilate each other? Explain your answer.
2. For each of edge, screw, and mixed dislocations, cite the relationship between the direction of the applied shear stress and the direction of dislocation line motion.
3. (a) Define a slip system.
(b) Do all metals have the same slip system? Why or why not?
4. (a) Compare planar densities (Section 3.11 and Problem 3.53) for the (100), (110), and (111) planes for FCC.
(b) Compare planar densities (Problem 3.54) for the (100), (110), and (111) planes for BCC.