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WorksheetsMETE230 - Chapter 4
Total questions: 10
Worksheet time: 5mins
Which of the following is NOT a point defect?
Vacancy
Interstitial atom
Edge dislocation
Substitutional impurity
Which type of dislocation has a Burgers vector perpendicular to the dislocation line?
Edge dislocation
Screw dislocation
Mixed dislocation
Planar dislocation
The number of vacancies in a material increases exponentially with:
Temperature
Stress
Grain size
Atomic radius
Which of the following best describes a grain boundary?
A perfect alignment of atoms in a lattice
The region between two differently oriented crystals
A type of point defect
A one-dimensional defect
What happens when a substitutional impurity atom is larger than the host atoms?
It creates a vacancy
It has no effect on the lattice
It causes distortion in the lattice
It produces compressive strain in the lattice
Which type of dislocation results in a helical atomic arrangement around the core?
Edge dislocation
Screw dislocation
Mixed dislocation
Interstitial dislocation
Grain boundaries generally have:
Lower energy than the bulk material
Higher energy than the bulk material
No effect on mechanical properties
A perfect atomic arrangement
Which of the following statements about twin boundaries is TRUE?
They separate grains with the same crystallographic orientation
They occur due to atomic diffusion
They lead to a mirror-image misorientation
They are the same as grain boundaries
In polycrystalline materials, smaller grain size generally leads to:
Increased strength
Decreased hardness
Lower dislocation density
Increased ductility
What is the primary difference between an interstitial defect and a substitutional defect?
The location of the impurity atom
The effect on electrical conductivity
The charge of the impurity atom
The change in crystal structure
