1. At 100°C Copper (Cu) has FCC unit cell structure with cell edge length of XA° . What is the approximate density of Cu (in g cm-3) at this temperature? (Atomic mass of Cu = 63.55 u)
1) 150/X3 2) 211/X3 3) 205/X3 4) 422/X3
2. On doping Ge metal with a little of In or Ga, one gets.......
1) p - type semi conductor 2) n - type semi conductor
3) Insulator 4) Rectifier
3. When Frenkel defects are created in an otherwise perfect ionic crystal, the density of the ionic crystal?
1) Increases 2) Decreases
3) Remains same 4) Oscillates with the number of defects
4. For orthorhombic system axial ratios are a ≠ b ≠ c and the axial angles are
1) α = β = γ ≠ 90° 2) α = β = γ = 90°
3) α = γ = 90°, β ≠ 90° 4) α ≠ β ≠ γ ≠ 90°
5. Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29 A° . The radius of sodium atom is approximately...
1) 1.86 A° 2) 3.22 A° 3) 5.723 A° 4) 0.93 A°
6. Percentage of free space in cubic close packed structure and in body centred packed structure are respectively...
1) 48% and 26% 2) 30% and 26% 3) 26% and 32% 4) 32% and 48%
7. The appearance of colour in solid alkali metal halides is generally due to
1) Interstitial positions 2) F - centres
3) Schottky defect 4) Frenkel defect
8. If a stands for the edge length of the cubic systems: simple cubic, body centred cubic and face centred cubic, then the ratio of radii of the spheres in these systems will be respectively 
9. How many unit cells are present in a cube shaped ideal crystal of NaCl of mass 1.0 gr?
1) 5.14 × 1021 2) 1.28 × 1021 3) 1.71 × 1021 4) 2.57 × 1021
10. Fraction of total volume occupied by atoms in a simple cubic cell is 
11. Fe3O4 is ferromagnetic at room temperature but at 850K it becomes
1) Diamagnetic 2) Ferromagnetic 3) Anti ferromagnetic 4) Paramagnetic
12. The 8 : 8 type of packing is present in
1) KCl 2) CaF2 3) CsCl 4) NaCl
13. The unit cell with crystallographic dimensions a = b ≠ c, α = β = γ = 90° is...
1) Cubic 2) Hexagonal 3) Tetragonal 4) Orthorhombic
14. CsCl crystallises in body centred cubic lattice. If ‘a’ is its edge length then which of the following expression is correct? 
15. A material was used as rectifier for changing alternate current into direct current. The material consists of
1) n - type semiconductor 2) p - type semiconductor
3) Combination of n - and p - type semiconductors (n - p junction)
4) Combination of an insulator and n - type semiconductor
ANSWERS: 1-4; 2-1; 3-3; 4-2; 5-1; 6-3; 7-2; 8-3; 9-4; 10-4; 11-4; 12-3; 13-3; 14-3; 15-3.
