MATSE 201 MIDTERM EXAM
1.
Which is true regarding the crystal systems?
A) they completely define a crystal structure
B) they describe the shape
... [Show More] of the unit cell.
C) there are 7 shapes that can completely fill 3D space through translational symmetry
D) all of the above.
Points Earned: 2.0/2.0
Correct Answer(s): C
2.
Which of the following is NOT one of the 7 crystal systems?
A) Tetragonal
B) Rhombohedral
C) Trigonal
D) Face centered cubic
Points Earned: 2.0/2.0
Correct Answer(s): D
3.
Elemental metals do not commonly crystallize in which of the following lattices
A) simple cubic
B) face-centered cubic
C) hexagonal close packed
D) body centered cubic.
Points Earned: 2.0/2.0
Correct Answer(s): A
4.
Which direction has the highest linear density in a crystal of Cu that crystallizes in the fcc?
A) [100]
B) [110]
C) [111]
D) (110)
Points Earned: 2.0/2.0
Correct Answer(s): B
5.
Which direction has the highest linear density in a crystal of Na that crystallizes in the bcc?
A) [110]
B) [100]
C) [111]
D) (111)
Points Earned: 2.0/2.0
Correct Answer(s): C
6.
In a BCC metal, the plane with the highest planer density is:
A) (100)
B) (110)
C) (111)
D) (200)
Points Earned: 2.0/2.0
Correct Answer(s): B
7.
The closest packed plane in a metal FCC structure is:
A) (100)
B) (110)
C) (111)
D) (200)
Points Earned: 2.0/2.0
Correct Answer(s): C
8.
Which is TRUE about Bragg’s Law?
A) It defines conditions necessary for diffraction in primitive cells
B) It is insufficient to predict diffraction in non-primitive cells
C) It relates the the path length difference between to diffracted beams to the lattice d-spacing
D) All of the above
Points Earned: 2.0/2.0
Correct Answer(s): D
9.
Which plane will show a peak on a diffraction pattern for alpha-Fe (metal bcc structure)?
A) (100)
B) (220)
C) (210)
D) (221)
Points Earned: 2.0/2.0
Correct Answer(s): B
10.
Which of the following statements about vacancies is true?
A) vacancies are always present in materials
B) as temperature increases, the number of vacancies will increase
C) as temperature decreases, the number of vacancies will increase
D) vacancies are considered linear defects
Points Earned: 2.0/2.0 [Show Less]