Tuesday 16 July 2013

Material Science/Mechanical Properties of Metals Multiple Choice Questions

Material Science/Mechanical Properties of Metals Multiple Choice Questions

Satish V. Kailas/IISc, Bangalore M4/V1/June 04/1

Multiple Choice Questions:

1. Time dependent permanent deformation is called ________________.
(a) Plastic deformation (b) Elastic deformation
(c) Creep (d) Anelastic deformation
2. Figure-out the odd point in the following
(a) Proportinal limit (b) Elastic limit (c) Yeild point (d) Fracture point
3. If a material is subjected to two incremental true strains namely ε1 and ε2, then the total true strain is
(a) ε1 * ε2 (b) ε1 - ε2 (c) ε1 + ε2 (d) ε1 / ε2
4. Engineering stress-strain curve and True stress-strain curve are equal up to
(a) Proportional limit (b) Elastic limit (c) Yeild point (d) Tensile strength point
5. Value of Poisson’s ratio for ionic solids in the range of
(a) 0.1 (b) 0.2 (c) 0.3 (d) 0.4
6. Hydrostatic stress results in the following
(a) Linear strain (b) Shear strain (c) Both linear and shear strains (d) None
7. High elastic modulus in materials arises from
(a) High strength of bonds (b) Weak bonds (c) combination of bonds (d) None
8. Change in elastic modulus for ordinary materials between 0K and melting point is
(a) 10-20% increase (b) 10-20% decrease (c) 80-90% decrease (d) 80-90% increase
9. Bauschinger effect
(a) Hysteresis loss during loading and unloading (b) Anelastic deformation
(c) Dependence of yield stress on path and direction (d) None
10. Shape of true stress-strain curve for a material depends on
(a) Strain (b) Strain rate (c) Temperature (d) All
11. Toughness of a material is equal to area under ____________ part of the stress-strain curve.
(a) Elastic (b) Plastic (c) Both (d) None
12. True stress-strain curve need to be corrected after
(a) Elastic limit (b) Yield limit (c) Tensile strength (d) no need to correct
13. Following condition represents onset of necking
(a) εu = n (b) εu = 1-n (c) εu = 1+n (d) εu = ln (1+n)
14. As compared with conventional stress-strain curve, the true stress-strain curve is
(a) Above and right (b) Below and right (c) Above and left (d) Below and left
15. According to distortion-energy criterion, yielding occurs when
(a) Distortion energy reaches a critical value
(b) Second invariant of the stress deviator exceeded some critical value
(c) Octahedral shear stress reaches a critical value
(d) All
16. von Mises and Tresca criteria give different yield stress for
(a) Uni-axial stress (b) Balanced bi-axial stress (c) Pure shear stress (d) All
17. Plastic deformation results from the following
(a) Slip (b) Twinning (c) Both (d) None
18. Time dependent recoverable deformation under load is called ____________ deformation.
(a) Elastic (b) Anelastic (c) Elastic after-effect (d) Visco-elastic
Material Science/Mechanical Properties of Metals Multiple Choice Questions
Satish V. Kailas/IISc, Bangalore M4/V1/June 04/2
Answers:
1. c
2. d
3. c
4. c
5. b
6. d
7. a
8. b
9. c
10. d
11. c
12. c
13. a
14. c
15. d
16. c
17. c
18. b

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