Mechanical Properties of Solids — 50 High-Yield MCQs (English)

Covers stress & strain, Hooke's law, elastic moduli (Young's, shear, bulk), torsion, bending, fracture, toughness, Poisson's ratio and material behaviour. Correct answer shown after each question.

50 MCQs
Mobile-friendly • SEO
Stress & Strain Elastic Moduli Torsion & Bending Fracture & Toughness
1. Tensile stress is defined as:
A. Force × area
B. Force / area
C. Area / force
D. Force + area
Answer: B
2. Longitudinal strain is:
A. ΔL
B. ΔL / L
C. L / ΔL
D. ΔL × L
Answer: B
3. Hooke's law in elastic region states that stress is proportional to:
A. Strain
B. Area
C. Volume
D. Time
Answer: A
4. Young's modulus E has SI units of:
A. N
B. N/m
C. N/m^2 (Pa)
D. m^2/N
Answer: C
5. Poisson's ratio ν is defined as ratio of:
A. Lateral strain / longitudinal strain
B. Longitudinal strain / lateral strain
C. Stress / strain
D. Force / area
Answer: A
6. Typical range of Poisson's ratio for most metals is approximately:
A. 0.0–0.1
B. 0.2–0.35
C. 0.5–0.7
D. >1
Answer: B
7. Relation between Young's modulus E, shear modulus G and Poisson's ratio ν for isotropic material is:
A. E = G(1+ν)
B. E = 2G(1+ν)
C. E = 3G(1−2ν)
D. E = G/(1+ν)
Answer: B
8. Bulk modulus K relates volumetric stress to volumetric strain. Its unit is:
A. Pa
B. m
C. N
D. None
Answer: A
9. The slope of linear portion of stress–strain curve gives:
A. Yield strength
B. Toughness
C. Young's modulus
D. Fracture stress
Answer: C
10. Elastic limit is the maximum stress up to which material:
A. Breaks immediately
B. Undergoes plastic deformation
C. Returns to original shape on unloading
D. Melts
Answer: C
11. Yield point on stress–strain curve indicates:
A. Onset of fracture
B. Onset of plastic deformation
C. Maximum elastic energy
D. Zero stress
Answer: B
12. Ultimate tensile strength is:
A. Stress at proportional limit
B. Maximum stress a material can withstand before necking
C. Stress at fracture
D. Zero
Answer: B
13. Toughness of material measures its ability to:
A. Stretch without breaking
B. Absorb energy before fracture
C. Resist corrosion
D. Conduct heat
Answer: B
14. Resilience is area under stress–strain curve up to:
A. Fracture point
B. Yield point
C. Ultimate strength
D. Zero stress
Answer: B
15. Ductile materials typically show:
A. Large plastic deformation before fracture
B. Little or no plastic deformation
C. Brittle fracture at elastic limit
D. No fracture
Answer: A
16. Hardness of a material is a measure of its resistance to:
A. Impact
B. Scratch or indentation
C. Heat
D. Electrical current
Answer: B
17. Shear stress τ equals shear force divided by:
A. Volume
B. Area
C. Length
D. Time
Answer: B
18. Shear modulus G relates shear stress to:
A. Shear strain
B. Volumetric strain
C. Longitudinal strain
D. Time
Answer: A
19. Bulk modulus K measures resistance to:
A. Shear
B. Volume change
C. Bending
D. Thermal expansion
Answer: B
20. For small strains, material is linear elastic if stress–strain relation is:
A. Nonlinear
B. Proportional
C. Random
D. Time-dependent only
Answer: B
21. Strain energy stored per unit volume (energy density) in linear elastic material under stress σ is:
A. σ^2 / (2E)
B. E/σ^2
C. σ/E
D. 2E/σ^2
Answer: A
22. In torsion of circular shaft, angle of twist φ = TL/(GJ). Here J is:
A. Polar moment of inertia
B. Area moment of inertia
C. Mass moment
D. None
Answer: A
23. Maximum shear stress in a solid circular shaft under torque T is at:
A. Centre
B. Outer surface
C. Mid-radius only
D. Zero everywhere
Answer: B
24. Flexural (bending) stress in beam is given by σ = M y / I where I is:
A. Area
B. Second moment of area (moment of inertia)
C. Mass
D. Length
Answer: B
25. For rectangular cross-section of width b and height h, moment of inertia about neutral axis is:
A. b h^3 / 12
B. b h^2 / 12
C. b^3 h /12
D. b h /12
Answer: A
26. Creep is time-dependent deformation under:
A. Rapid loading
B. Sustained load at elevated temperature
C. No load
D. Shear only
Answer: B
27. Fatigue failure occurs due to:
A. Single static overload
B. Repeated cyclic stresses below ultimate strength
C. High temperature only
D. Corrosion only
Answer: B
28. Hardness tests (Brinell, Vickers) approximate which property?
A. Elastic modulus
B. Yield or resistance to plastic deformation
C. Density
D. Thermal conductivity
Answer: B
29. For a wire of length L and cross-sectional area A, extension under tensile load F is ΔL = FL/(AE). This formula assumes:
A. Large plastic deformation
B. Linear elasticity and uniform cross-section
C. Variable E with position
D. None
Answer: B
30. Poisson's effect causes lateral contraction when a bar is:
A. Sheared
B. Stretched in longitudinal direction
C. Heated only
D. Bent
Answer: B
31. Young's modulus for steel is approximately:
A. 2×10^9 Pa
B. 2×10^11 Pa
C. 2×10^7 Pa
D. 2×10^5 Pa
Answer: B
32. A brittle material generally exhibits:
A. Large plastic deformation before fracture
B. Little or no plastic deformation and sudden fracture
C. Flow under load
D. High toughness
Answer: B
33. The modulus of resilience is maximum energy per unit volume that material can absorb without:
A. Elastic deformation
B. Yielding (plastic deformation)
C. Fracture
D. Heating
Answer: B
34. Stress concentration factor is high near:
A. Smooth uniform section
B. Notches, holes, sharp corners
C. Middle of large plate
D. Far from load application
Answer: B
35. For two springs in series, equivalent spring constant k_eq is:
A. k1 + k2
B. (k1 k2)/(k1 + k2)
C. k1 k2
D. k1 − k2
Answer: B
36. For springs in parallel, equivalent stiffness is:
A. k1 + k2
B. (k1 k2)/(k1 + k2)
C. k1 k2
D. k1 − k2
Answer: A
37. Ultimate tensile strength is typically measured in:
A. Pa
B. m
C. kg
D. J
Answer: A
38. Work-hardening (strain hardening) increases material's:
A. Ductility
B. Yield strength
C. Corrosion rate
D. Electrical conductivity
Answer: B
39. Fracture toughness quantifies material's resistance to:
A. Crack initiation and propagation
B. Shear only
C. Thermal expansion
D. Elastic deformation
Answer: A
40. For pure bending, neutral axis experiences:
A. Maximum tensile stress
B. Zero longitudinal stress
C. Maximum compressive stress
D. Shear stress only
Answer: B
41. True stress differs from engineering stress because it accounts for:
A. Original cross-section only
B. Instantaneous cross-section during deformation
C. Time only
D. Temperature only
Answer: B
42. A material with high Young's modulus is generally:
A. Very flexible
B. Very stiff
C. Highly ductile
D. Low density
Answer: B
43. In tensile test, necking begins when engineering stress reaches:
A. Proportional limit
B. Ultimate tensile strength
C. Yield strength
D. Zero
Answer: B
44. Anisotropic material has mechanical properties that:
A. Are same in all directions
B. Vary with direction
C. Depend only on temperature
D. Are zero
Answer: B
45. For linear elastic isotropic material, Poisson's ratio must lie between:
A. −1 and 0.5
B. 0.5 and 1
C. 1 and 2
D. 0 and 10
Answer: A
46. Brittle fracture is usually characterized by:
A. Significant plastic deformation
B. Little plastic deformation and rapid crack propagation
C. High energy absorption
D. Ductile necking
Answer: B
47. The area under complete stress–strain curve up to fracture measures:
A. Toughness
B. Resilience
C. Hardness
D. Yield strength
Answer: A
48. Mechanical testing to determine elastic modulus commonly uses:
A. Tensile test
B. Hardness test only
C. Chemical analysis
D. Electrical test
Answer: A
49. Fatigue limit (endurance limit) indicates stress amplitude below which:
A. Material will always fail
B. Material may endure infinite number of cycles without failure
C. Material melts
D. Material becomes brittle
Answer: B
50. For isotropic linear elastic material, three independent elastic constants can be chosen as:
A. E, G, K
B. Density, mass, volume
C. Yield strength, toughness, hardness
D. Temperature, pressure, time
Answer: A