Engineering Questions with Answers - Multiple Choice Questions
Materials Science MCQ’s – Lattice Strain
1 - Question
Which of the following is not a lattice strain due to dislocation?
a) Tensile lattice strain
b) Compressive lattice strain
c) Shear lattice strain
d) Torsional lattice strain
View Answer
Explanation: Due to the movement of dislocation in a material tensile lattice strain, compressive lattice strain and shear lattice strain are felt by the neighboring atoms in the lattice.
2 - Question
When atoms are deformed approximately what fraction of deformation energy is retained internally?
a) 5%
b) 10%
c) 15%
d) 20%
View Answer
Explanation: When a metal is plastically deformed, the atoms inside the lattice retain approximately 5% of the deformation energy.
3 - Question
For which of the following dislocation the strain is pure shear?
a) Screw dislocation
b) Jog dislocation
c) Mixed dislocation
d) Edge dislocation
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Explanation: In screw dislocation only, pure shear stress is felt by the body while in edge dislocation, jog dislocation and mixed dislocation, other types of lattice strains also exist.
4 - Question
Which of the following will decrease lattice strain?
a) Line defects
b) Point defects
c) Dislocation
d) Heating the material
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Explanation: When a body is heated the strain on the body decreases whereas it increases when defects like line defects, point defects and dislocation are present in the lattice.
5 - Question
How high can dislocation density of a material be when it is heavily deformed?
a) 1010 mm-2
b) 109 mm-2
c) 1011 mm-2
d) 1012 mm-2
View Answer
Explanation: The dislocation density of a material increases with increase in deformation and the heavily deformed material will have dislocation density up to 1010 mm-2.
6 - Question
Two edge dislocation on same slip plane and the same sign will ________
a) Exert attractive force
b) Exert no force
c) Exert repulsive force
d) Exert shearing force
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Explanation: When two dislocations are of the same sign and are located on the same slip plane they exert a repelling force on each other.
7 - Question
Dislocation annihilation occurs when two dislocations of different signs meet each other on the same plane.
a) True
b) False
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Explanation: When two dislocations of opposite sign are on located on same slip plane the two dislocations exert an attractive force and then they will start moving towards each other on meeting dislocation annihilation takes place.
8 - Question
Shear strains are observed in the vicinity of the edge dislocation.
a) True
b) False
View Answer
Explanation: Along with tensile and compressive strains, in edge dislocation shear strains are also observed in the neighboring regions of the dislocation.