This set of Materials Science Multiple Choice Questions & Answers (MCQs) focuses on “Creep”.
1. Which of the following is a slow rise of plastic deformation under the action of shear stresses when it is below the yield strength of the material?
a) Brittle fracture
b) Ductile fracture
c) Creep
d) Fatigue
View Answer
Explanation: Creep is defined as a slow rise of plastic deformation under the action of shear stresses when it is below the yield strength of the material.
2. Which of the following isn’t a stage of creep?
a) Transient creep stage
b) Constant creep stage
c) Fracture stage
d) Steady stage creep stage
View Answer
Explanation: Transient creep stage, steady stage creep stage and fracture stage are the three stages of creep called as primary, secondary and tertiary creep respectively.
3. Which of the following stage is also known as the unstable stage?
a) Transient creep stage
b) Constant creep stage
c) Fracture stage
d) Steady stage creep stage
View Answer
Explanation: Transient stage or primary creep is also called the unstable stage and in this stage, there is a gradual decrease in deformation rate to a definite constant value.
4. In which of the stages, do we observe a constant deformation rate?
a) Transient creep stage
b) Constant creep stage
c) Fracture stage
d) Steady stage creep stage
View Answer
Explanation: Steady stage creep stage or secondary creep is the stage which is characterized by a constant deformation rate.
5. In which of the following stages do the deformation rate increases and causes failure?
a) Transient creep stage
b) Constant creep stage
c) Fracture stage
d) Steady stage creep stage
View Answer
Explanation: Fracture stage or the tertiary creep is that stage where the material deformation rate increases and finally results in failure of that material.
6. Creep depends on temperature.
a) True
b) False
View Answer
Explanation: The above statement is true. Creep is dependent on temperature and stress. Increase in temperature for a constant stress can decrease the time of the second stage and hence accelerate failure.
7. Above what temperature is the phenomenon of creep important in steel?
a) 200 °C
b) 500 °C
c) 300 °C
d) 600 °C
View Answer
Explanation: For steel, the phenomenon of creep is important at a temperature above 300 °C while in polymer it is significant at room temperature.
8. Which of the following is true?
a) The slope of the strain-time graph increases with temperature and stress
b) The slope of strain-time graph decreases with temperature
c) The slope of strain-time graph decreases with stress
d) The slope of strain-time graph does not depend on temperature or stress
View Answer
Explanation: The slope of a strain-time graph increases with the increase in temperature. The slope of a strain-time graph increases with the increase in stress too.
9. What is the nature of the curve of a viscous creep?
a) Parabola
b) Hyperbola
c) Straight line passing through an origin
d) Circle
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Explanation: The nature of the curve for a viscous creep is a straight line passing through the origin while it is a horizontal line for sudden creep.
10. Diffusion creep is a type of creep. The slope of a strain-time graph increases with the increase in temperature.
a) True
b) False
View Answer
Explanation: Diffusion creep, logarithmic creep and recovery creep are the three major types of creep. This classification is according to the temperature at which the creep occurs. Diffusion creep occurs at a temperature above 0.7 Tm(melting point of material).
Sanfoundry Global Education & Learning Series – Materials Science.
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