This set of Materials Science Multiple Choice Questions & Answers (MCQs) focuses on “Lattice Strain”.
1. 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
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. When atoms are deformed approximately what fraction of deformation energy is retained internally?
Explanation: When a metal is plastically deformed, the atoms inside the lattice retain approximately 5% of the deformation energy.
3. For which of the following dislocation the strain is pure shear?
a) Screw dislocation
b) Jog dislocation
c) Mixed dislocation
d) Edge dislocation
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. Which of the following will decrease lattice strain?
a) Line defects
b) Point defects
d) Heating the material
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. 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
Explanation: The dislocation density when the body or material is heavily deformed due to plastic deformation can be as high as 1010 mm-2.
6. 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
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. Dislocation annihilation occurs when two dislocations meet.
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. Shear strains are observed in the vicinity of the edge dislocation.
Explanation: Along with tensile and compressive strains, in edge dislocation shear strains are also observed in the neighboring regions of the dislocation.
Sanfoundry Global Education & Learning Series – Materials Science.
To practice all areas of Materials Science, here is complete set of 1000+ Multiple Choice Questions and Answers.