This set of Mechanical Behaviour Multiple Choice Questions & Answers (MCQs) focuses on “Plastic Deformation”.
1. What is the atomic density on the prismatic plane?
a) 1/a2
b) 2/ac
c) 2/a2
d) 2/√3a2
View Answer
Explanation: Basal plane and prismatic planes are the two types of the plane that are present in HCP crystal structure. And the atomic density of the prismatic and basal plane is given by 2/ac and 2/√3a2 respectively.
2. What is atomic density on {1 1 1} plane in fcc?
a) 4/√3a2
b) √2/a2
c) 2/a2
d) 1/a2
View Answer
Explanation: The atomic density is 4/√3a2 on {1 1 1} plane in fcc. √2/a2 is on {1 1 0} plane. While 2/a2 is on {1 0 0} plane.
3. What is interplanar spacing for {1 1 1} planes in BCC?
a) a/2√3
b) a/√2
c) a/2
d) a√3/2
View Answer
Explanation: Interplanar spacing for {1 1 1} planes is a/2√3 in bcc crystal. a/√2 is for {1 1 0} planes. While a/2 is for {1 0 0} planes in BCC crystal.
4. What is interplanar spacing for {1 1 0} planes in BCC?
a) a/√3
b) a/2√2
c) a/2
d) a/√2
View Answer
Explanation: Interplanar spacing is a/2√2 for {1 1 0} planes in BCC structure. It is a/√3 for {1 1 1} planes. While a/2 for {1 0 0} planes in BCC structure.
5. {1 1 1} are called _____ planes.
a) Basal
b) Prismatic
c) Octahedral
d) Cube
View Answer
Explanation: The planes {1 1 1} already called octahedral planes. Basal planes are {0 0 0 1}. Prismatic planes are {1 0 1 0}.
6. c/a ratio is highest for ______ and least for _____
a) Mg, Co
b) Zr, Ti
c) Cd, Be
d) Hg, Be
View Answer
Explanation: c/a ratio is highest for Cd (1.886). It is lowest for Be (1.567). Its ideal ratio is 1.632.
7. What is c/a ratio of magnesium?
a) 1.856
b) 1.624
c) 1.593
d) 1.567
View Answer
Explanation: c/a ratio for Mg is 1.624. It is lesser than ideal c/a ratio. 1.856, 1.593 and 1.567 are ratios for Zn, Zr and Be.
8. What is c/a ratio of titanium?
a) 1.886
b) 1.632
c) 1.587
d) 1.586
View Answer
Explanation: c/a ratio for Ti is 1.587. While 1.632 is ideal c/a ratio. 1.886 and 1.586 are ratios for Cd and Hg.
9. Value of CRSS for HCP crystal _____ with increasing temperature.
a) Increases
b) Decreases
c) Remains constant
d) First decreases then remain unaffected
View Answer
Explanation: Yield strength increases significantly with decreasing temperature below 300 K. Above this temperature yield strength remains unaffected. It is similar to P-N stress relation.
10. Value of CRSS ____ with increasing impurity contents in a metal crystal.
a) Increases
b) Decreases
c) Remains constant
d) May increase or decrease
View Answer
Explanation: CRSS increases with an increase in impurity contents in metal. As silver containing impurities 0.01% and 0.03%, CRSS values are 0.47 MPa and 0.71 MPa. It is also observed in other metals.
11. The slope of stress-strain curve in plastic range is _____
a) Rate of strain hardening
b) Bauschinger effect
c) True strain
d) Resolved shear stress
View Answer
Explanation: Strain hardening behaviour is represented by the stress-strain curve. The slope of this curve is rate of strain hardening. It is the reason behind calling these curves ‘hardening curves’.
12. Pile up of dislocations causes strain hardening.
a) True
b) False
View Answer
Explanation: Pile up of dislocations makes sessile dislocations. These dislocations act as a barrier for other dislocations movement. The effect of strain hardening rises.
13. Recrystallization temperature is defined as the temperature at which cold worked metal recrystallizes completely in 1 hour.
a) True
b) False
View Answer
Explanation: Recrystallization temperature is arbitrarily defined as the temperature at which 50% of cold worked metal recrystallizes in 1 hour. It ranges from 0.3Tm to 0.5Tm. Here Tm is the melting temperature in Kelvin.
14. Ideal rolling texture is developed after ____ cold deformation.
a) 20-30%
b) 40-50%
c) 60-70%
d) 80-90%
View Answer
Explanation: Ideal rolling texture is developed after extensive cold deformation. It is 80-90%.
Sanfoundry Global Education & Learning Series – Mechanical Behaviour & Testing of Materials.
To practice all areas of Mechanical Behaviour & Testing of Materials, here is complete set of 1000+ Multiple Choice Questions and Answers.
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