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
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%
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
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
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
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
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