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1) Find the number of atoms in a cubic based unit cell having one atom on
each corner and two atoms on each diagonal.
a) 9
b) 13
c) 5
d) 18
ANSWER : 9
2) Brass is a type of …………… crystal.
a) Covalent
b) Ionic
c) Metallic
d) None of these.
ANSWER : Metallic
3) A NaCl crystal is found to have CsCl structure because it might have been
subjected to:
a) High temperature
b) Low temperature
c) High pressure
d) Low pressure
ANSWER : High pressure
4) The particles when placed in the adjacent rows show a horizontal as well
as vertical alignment and form squares. This type of packing is known as:
a) Hexagonal close packing
b) Square close packing
c) Cubic close packing
d) Both b and c
ANSWER : Square close packing
5) Calculate the radius of the anion B, if the radius of the cation A is
100pm. The solid AB has NaCl structure.
a) 240 pm
b) 140 pm
c) 340 pm
d) 241 pm
ANSWER : 241 pm
6) Which among the following does not have a close packed structure?
a) Be
b) Ni
c) Ne
d) He
ANSWER : He
7) In the close packed crystal of compound AB. Predict the co-ordination
number of A+, if two ions A+ and B- have radii
88 and 200 pm respectively.
a) 6
b) 4
c) 2
d) 8
ANSWER : 6
8) Calculate the interionic distance in CsCl if it has bcc arrangement and
its unit cell edge length is 400 pm.
a) 346 pm
b) 346.4 pm
c) 346.8 pm
d) 345 pm
ANSWER : 346.4 pm
9) …………. is used in the solar cell.
a) Ti
b) Sn
c) Cs
d) Si
ANSWER : Si
10) Find the co-ordination number of the cations and anions in the calcium
fluoride structure.
a) 4 and 4
b) 4 and 8
c) 8 and 4
d) 6 and 6
ANSWER : 8 and 4
11) From the following find the ferroelectric compound.
a) BaTiO3
b) Pb2O3
c) K4 [Fe (CN) 6]
d) None of these
ANSWER : BaTiO3
12) ………… ionic compound has maximum distance between the centres of the
cations and anions.
a) CsI
b) CsF
c) LiI
d) LiF
ANSWER : CsI
13) Schottky defect in crystals is observed when:
a) Density of the crystal is increased.
b) Unequal number of cations and anions are missing from the lattice.
c) Equal number of cations and anions are missing from the lattice.
d) An ion leaves its normal site and occupies an interstitial site.
ANSWER : Equal number of cations and anions are missing from the lattice.
14) How many kinds of space lattices are possible in a crystal?
a) 230
b) 14
c) 23
d) 7
ANSWER : 14
15) Potassium crystallizes with a:
a) Simple cubic lattice.
b) Face-centred cubic lattice.
c) Orthorhombic lattice.
d) Body-centred cubic lattice.
ANSWER : Body-centred cubic lattice.
16) Calculate the density of an iron atom having rock like structure and
effective radius of 1.42Å. (Fe = 56 amu)
a) 5.74 kg m-1
b) 5.74 g cm-1
c) 3.01 kg m-1
d) 3.01 g cm-1
ANSWER : 5.74 g cm-1
17) Arrange the following in the increasing order of nuclear charge? Al, Mg,
Na.
a) Al < Mg < Na
b) Na < Mg < Al
c) Mg < Al < Na
d) None of these
ANSWER : Al < Mg < Na
18) Substances which show permanent magnetism even in the absence of the
magnetic field are called?
a) Ferromagnetic substances.
b) Ferromagnetic substances.
c) Diamagnetic substances.
d) Anti-ferromagnetic substances.
ANSWER : Ferromagnetic substances.
19) Polar crystals when heated produce a small electric current. The
electricity thus produced is called:
a) Ferroelectricity.
b) Pyroelectricity.
c) Piezoelectricity.
d) None of these.
ANSWER : Pyroelectricity.
20) Which among the following is not a property of Amorphous solids?
a) No sharp melting point.
b) Conversion into crystalline on heating.
c) Existence of short – range order.
d) None of these.
ANSWER : None of these.
21) Pure silicon and germanium are:
a) Insulators
b) Conductors
c) Semiconductors
d) Both b and c
ANSWER : Semiconductors
22) Doping is a process of introducing a defect in a crystal by adding:
a) Impurity to it
b) Salt to it
c) Water to it
d) None of these.
ANSWER : Impurity to it
23) Ferromagnetic substances show ……………. even when the external magnetic
field is removed.
a) Permanent magnetism
b) Temporary magnetism
c) No magnetism
d) None of these.
ANSWER : Permanent magnetism
24) Which among the following is an example of Amorphous solid?
a) Glass
b) Fused silica
c) Both a and b
d) Only one among a and b
ANSWER : Both a and b
25) Calculate the radius of aluminium atom in metres when the density of
aluminium is 2700 kg m-3. Aluminium crystallises in face- centred
cubic lattice. (Atomic mass of Al = 27)
a) 1.11 x 10-10
b) 1.11 x 10-12
c) 1.43 x 10-12
d) 1.43 x 10-10
ANSWER : 1.43 x 10-10
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