1. Which of the following statements are true for the line defect

A) Burger vector is parallel to dislocation in an edge dislocation
B) Burger vector is perpendicular to dislocation in an edge dislocation
C) Burger vector is perpendicular to dislocation in a screw dislocation
D) Burger vector is parallel to dislocation in a screw dislocation

2. A polymer bar's dimensions are 1 in x 2 in x 15 in. The polymer has a modulus of elasticity of 600,000 psi. What force is required to stretch the bar elastically to 15.25 in.?

A) 10,000 lb
B) 20,000 lb
C) 30,000 lb
D) 40,000 lb

3.A 3-in. diameter rod of copper is to be reduced to a 2-in. diameter rod by being pushed through an opening. The modulus of elasticity for the copper is 17 x 106 psi and the yield strength is 40,000 psi. To account for the elastic strain, the diameter of the opening would be

A) 2.521 in
B) 3.0 in
C) 0.895 in
D) 1.995 in