Material Science Mid - I, September - 2014

1.Assign the Bravais lattice type for the following unit-cell structure  
  • Cubic I
  • Orthorhombic I
  • Tetragonal I
  • Monoclinic
Answer: C
2.How many nearest neighbours are there for an atom in a hexagonal close-packed crystal structure?
  • 6
  • 12
  • 18
  • 24
Answer: B
3.Which of the following set of planes are parallel?
  • (111), (100), (102)
  • (101), (202), (303)
  • (222), (202), (022)
  • None of the above
Answer: B
5.Which of the following is cubic system?
  • a = b = c, α = β = γ = 90°
  • a = b ≠ c, α = β = γ = 90°
  • a = b = c, α ≠ β ≠ γ ≠ 90°
  • None of the above
Answer: A
6.Which of the following is cubic system?
  • P, I, C
  • P, I, C, F
  • I, F
  • None of the above
Answer: B
7.How many number of atoms in the FCC structure?
  • 8
  • 12
  • 4
  • 1
Answer: C
8.What is the packing density of BCC structure?
  • 54%
  • 68%
  • 74%
  • None of the above
Answer: B
9.Repeatable entity of a crystal structure is known as
  • Crystal
  • Lattice
  • Unit cell
  • Miller indices
Answer: C
10.Coordination number in simple cubic crystal structure
  • 1
  • 2
  • 3
  • 4
Answer: B
11.____________________ are widely used to study the structure of materials.
Answer: x-rays
12.The powder camera is also called ____________________.
Answer: Debye Scherrer camera
13.For diffraction to occur the wavelength of x-rays should not exceed ____________________ the interplanar spacing.
Answer: Twice
14.____________________ is a function of the miller indices and lattice parameters as well as the crystal structure.
Answer: Interplanar spacing
15.An ____________________ is simply the edge of an extra inserted fractional plane of atoms.
Answer: Edge dislocation
16.Burger vector is parallel to the dislocation line in ____________________.
Answer: Screw dislocation
17.___________________ reduces the dielectric strength drastically.
Answer: Defect
18.Coordination number for closest packed crystal structure is ____________________.
Answer: 12
19.Gibbs phase rule for general system is ___________________.
Answer: P+F = C+2
20.Line defects are also called as ____________________
Answer: Dislocations