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WorksheetsPRETEST FINAL PERIOD IMPERFECTION, DIFFUSION
Total questions: 50
Worksheet time: 25mins
Vacancy defects in solids is a sub type of __________
Point imperfections
Line imperfections
Volume imperfections
Surface imperfections
Substitution of a foreign atom in the site of parent atom in the crystal is a________________?
Vacancy defect
Substitution impurity
Volume imperfections
Stacking Defect
Edge dislocation imperfection is a sub type of _____________
Point imperfections
Line imperfections
Volume imperfections
Surface imperfections
Displacement of an ion from regular location to interstitial location is known as ____________
Vacancy defect
Line imperfection
Schottky’s defect
Frenkel defect
When a pair of cation and anion are missing in a crystal, it is called ____________.
Vacancy defect
Line imperfection
Schottky’s defect
Frenkel defect
Which one of the following is not a zero-dimensional defect?
Vacancy defect
Substitution imperfection
Schottky’s defect
Screw dislocation
Twin or Twinning is a category of ________.
Point imperfections
Line imperfections
Volume imperfections
Surface imperfections
As the grain size of a metal increases, its ductility ________.
Decreases
Increases
Remains constant
No effect of grain size on ductility
Phenomenon of cross slip occurs in ________.
Point imperfections
Line imperfections
Volume imperfections
Surface imperfections
TWO types of solid solution :
Subsequences solid solution
Substitution solid solution
Interstellar solid solution
Interstitial solid solution
Substitutional solid solution
Interstate solid solution
Interstitial solid solution
Substance solid solution
TWO types of substitutional solid solution:
First In First Out
Fist In Last Out
Disorderd / Randomly Arrage
Ordered / Properly Arrange
Which diagram shows Interstitial Solid Solution?
(a)
This is a _______________________ .
Stress-Strain Diagram
Phase Diagram
Periodic Table
Binary Isomorphous System
Equilibrium Phase Diagram is __________________________ .
a state of balance of stability
a graphical representations of what phases are present in a materials system at various temperatures, pressures and compositions.
a portion of system that has uniform physical and chemical characteristics.
a percentage of certain materials contains purposely or not added to another material.
The diagram shows _________________________ .
Metal liquifying process
Metal solidification process
Metal iron process
Metal impurities process
Defects in crystal structure can improve strength of the material. This statement is
True
False
Which of the following is a planar defect?
vacancy
grain boundary
dislocation
second phase particle
Cu-Ag system has
limited solid solubility
extensive solid solubility
Presence of imperfections in the crystal
increase enthalpy & decrease configuration entropy
increase enthalpy & increase configuration entropy
decrease enthalpy & decrease configuration entropy
decrease enthalpy & increase configuration entropy
Imperfections will be thermodynamically stable if
free energy decreases
free energy increases
In a single Schottky imperfection in Calcium chloride crystal
one cataion and one anion is missing
one cataion and two anions are missing
cataion in misplaced to the interstitial void space
anion is misplaced to the interstitial void space
If Ca(+2) ion is substituted for a Na(+1) ion in NaCl crystal. Then what type of point defect will be observed?
Fraekel defect
Schottky defect
Cation vacancy
Anion vacancy
With the increase of temperature vacancy concentration
increases
decreases
does not change
Among solids, the highest melting point is exhibited by
Covalent solids
Ionic solids
Pseudo solids
Molecular solids
The major binding force of diamond, silicon and quartz is
Electrostatic force
Electrical attraction
Covalent bond force
Non-covalent bond force
In graphite electrons are
Localised on each carbon atom
Spread out between the sheets
Localised on every third carbon atom
Present in antibonding orbital
Which defect is shown in the given figure?
Frenkel defect
Impurity defect
Schottky defect
Vacancy defect
Which of the following statements is not correct ?
Vacancy defect results in decrease in density of substance.
Vacancy defect can develop when a substance is heated.
Interstitial defect increases the density of the substance.
Ionic solids show interstitial
White crystal of zinc oxide is heated
(i) Metal excess defect is created.
(ii) Presence of extra cation at interstitial site.
(iii) It loses oxygen and turns yellow.
(iv) Free electron are created.
All statement(s) are correct.
(i), (ii) and (iv)
(i), (ii) and (iii)
(ii) and (iv)
When electrons are trapped into the crystal in anion vacancy, the defect is known as :
Schottky defect
Frenkel defect
Stoichiometric defect
F-centre
Schottky defect in crystals is observed when,
An ion leaves its normal site and occupies an interstitial site
Unequal number of cations and anions are missing from the lattice
Density of the crystal increases
Equal number of cations and anions are missing from the lattice
Crystal defect indicated in the diagram is,
Interstitial defect
Schottky defect
Frenkel defect
Frenkel and Schottky defect
- Dislocation is fall under categories of "line defect'.
correct
incorrect
An extra atom is present in the void between atoms is called "vacancy".
correct
incorrect
Less distortion is created under self-interstitial defect.
correct
incorrect
More than one possible valence state of an ion is called Non-Stoichiometry defect.
correct
incorrect
Dislocation has less influence to material properties.
correct
incorrect
Twist boundary is formed by edge dislocation aligning up in a line.
correct
incorrect
Twin boundary is formed either by stress or annealing.
correct
incorrect
Diffusion is a process of mass transfer by movement of atoms from lower chemical potential to higher chemical potential.
correct
incorrect
Vacancy diffusion is more rapid than interstitial diffusion.
correct
incorrect
Steady state diffusion occurs due to concentration gradient
correct
incorrect
In non-steady state diffusion, the concentration gradient will not change with time.
correct
incorrect
Diffusion coefficient depend on diffusing species, not the mechanism followed for diffusion.
correct
incorrect
Regions of imperfection provide easier path for diffusion.
correct
incorrect
The simplest of the point defects is
Crystalline defect
Vaccancy
Self-interstitial
Imperfections
Atoms that contain large numbers of various defects
Crystalline defect
Vaccancy
Self-interstitial
Imperfections
Is an atom from the crystal that is crowded into an interstitial site, a small void space that under ordinary circumstances is not occupied
Crystalline defect
Vaccancy
Self-interstitial
Imperfections
Is a linear or one-dimensional defect around which some of the atoms are misaligned.
Dislocation
Edge Dislocation
Screw Dislocation
Mixed Dislocation
