This set of Materials Science Multiple Choice Questions & Answers (MCQs) focuses on “Brittle Fracture”.
1. Which of the following is associated with minimum plastic deformation?
a) Ductile fracture
b) Brittle fracture
c) Fatigue
d) It doesn’t occur during fracture
View Answer
Explanation: In brittle fracture, the plastic deformation occurring in the body is minimum and there is a rapid movement of crack with a very little amount of plastic deformation.
2. Which of the following fracture mechanisms in which the crack propagates more rapidly?
a) Ductile fracture
b) Brittle fracture
c) Fatigue
d) It doesn’t occur during fracture
View Answer
Explanation: In brittle fracture, after a little plastic deformation the material fractures and then the crack propagates rapidly, making the material break.
3. Below which point does brittle fracture occur?
a) Ultimate tensile strength
b) Fracture point
c) Elastic limit
d) Yield point
View Answer
Explanation: Fatigue is one of the mechanical failures of the metals that occur due to cyclic loading. It occurs when the stress applied is less than the yield stress or yield point.
4. Cleavage planes are a term associated with ductile fracture.
a) True
b) False
View Answer
Explanation: Brittle fracture occurs generally along crystal planes called cleavage planes where the number of atomic bonds are relatively low.
5. The tendency of brittle fracture increases with:
a) Decreasing temperature
b) Increasing temperature
c) Decrease in strain rate
d) It doesn’t depend on temperature or strain rate
View Answer
Explanation: The tendency of brittle fracture to be observed increases as the temperature decreases.
6. The tendency of brittle fracture increases with:
a) Increasing temperature
b) Increase in strain rate
c) Decrease in strain rate
d) It doesn’t depend on temperature or strain rate
View Answer
Explanation: The tendency of brittle fracture to be observed increases as the strain rate of the body increases. As the strain rate increases the body dislocations start piling up and ultimately leading to failure.
7. Which of the following statement is true regarding the toughness of a metal?
a) Energy consumed is less in ductile fracture than brittle fracture
b) Energy consumed is more in ductile fracture than brittle fracture
c) Energy consumed in the brittle fracture is same as the ductile fracture
d) Energy consumed is more in brittle fracture than ductile fracture
View Answer
Explanation: As brittle fracture less plastic deformation and absorbs less amount of energy before breaking, the energy consumed by brittle fracture is less than the ductile fracture.
8. Which of the theory is related to brittle fracture?
a) Laundau theory
b) Dirac hole theory
c) Valence bond theory
d) Griffith’s theory
View Answer
Explanation: Griffith’s theory is a theory which was postulated by Griffith and is related to brittle fracture. It is known as Griffith’s theory of brittle fracture.
9. The graph for Griffith’s crack is ____________
a) An ellipse
b) A circle
c) A straight line
d) A hyperbola
View Answer
Explanation: The graph for Griffith’s crack is an ellipse. The graph tensile stress applied perpendicular to the length of crack and the length of the crack.
10. Surface energy of the specimen increases when the crack lengthens.
a) True
b) False
View Answer
Explanation: When the crack lengthens the surface area increases and hence the surface energy of the specimen increases.
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.
