1. Stress in tissues is defined as:
(A) Force per unit area
(B) Force × displacement
(C) Length ÷ original length
(D) Energy per unit mass
2. Strain is defined as:
(A) Change in force ÷ Area
(B) Change in length ÷ Original length
(C) Load ÷ Volume
(D) Force × Area
3. The unit of stress is:
(A) Newton
(B) Joule
(C) Pascal
(D) Watt
4. Strain is a:
(A) Dimensionless quantity
(B) Quantity measured in Pascal
(C) Vector
(D) Scalar with unit N/m²
5. Which type of stress tends to pull tissues apart?
(A) Compressive
(B) Tensile
(C) Shear
(D) Torsional
6. Which type of stress shortens tissues?
(A) Compressive
(B) Tensile
(C) Shear
(D) Rotational
7. Which type of stress acts parallel to a surface?
(A) Tensile
(B) Compressive
(C) Shear
(D) Normal
8. Stress-strain curve of bone shows:
(A) Elastic and plastic regions
(B) Only elastic region
(C) Only plastic region
(D) No deformation
9. The slope of stress-strain curve in elastic region is called:
(A) Yield point
(B) Young’s modulus
(C) Fracture strength
(D) Poisson’s ratio
10. A material with high Young’s modulus is:
(A) Very stiff
(B) Very flexible
(C) Weak
(D) Easily compressed
11. Bone shows more resistance to:
(A) Compression
(B) Tension
(C) Shear
(D) Torsion
12. Tendons show more resistance to:
(A) Tension
(B) Compression
(C) Shear
(D) Torsion
13. Cartilage shows better resistance to:
(A) Compression
(B) Tension
(C) Shear
(D) Fracture
14. Which point on stress-strain curve marks permanent deformation?
(A) Elastic limit
(B) Yield point
(C) Fracture point
(D) Ultimate strength
15. Strain energy is stored mainly in:
(A) Elastic region
(B) Plastic region
(C) At fracture point
(D) Beyond failure
16. The area under stress-strain curve represents:
(A) Work done per unit volume
(B) Velocity
(C) Force × mass
(D) Elastic modulus
17. Poisson’s ratio relates:
(A) Lateral strain to longitudinal strain
(B) Stress to strain
(C) Force to area
(D) Energy to strain
18. Normal value of Poisson’s ratio for bone is about:
(A) 0.1
(B) 0.3
(C) 0.5
(D) 1.0
19. Hooke’s law states:
(A) Stress ∝ Strain within elastic limit
(B) Stress = Strain²
(C) Strain ∝ Force
(D) Stress independent of strain
20. Viscoelastic tissues show:
(A) Elastic behavior only
(B) Plastic behavior only
(C) Both elastic and viscous behavior
(D) No stress response
21. The stress at which tissue fails is called:
(A) Yield strength
(B) Fracture strength
(C) Elastic limit
(D) Strain limit
22. Ultimate tensile strength of a tissue means:
(A) Maximum stress it can withstand
(B) Minimum stress it can withstand
(C) Elastic region slope
(D) Permanent deformation
23. Which tissues demonstrate large strain before failure?
(A) Brittle tissues
(B) Ductile tissues
(C) Rigid tissues
(D) Compact bone
24. A brittle material fails:
(A) After large strain
(B) After small strain
(C) With no stress
(D) With no force
25. Stress concentration occurs at:
(A) Smooth surfaces
(B) Sharp notches and irregularities
(C) Uniform areas
(D) Balanced load distribution
26. Which structure behaves more elastically?
(A) Bone
(B) Tendon
(C) Ligament
(D) Cartilage
27. The viscoelastic property of creep means:
(A) Strain increases with constant stress over time
(B) Stress increases with constant strain
(C) Stress remains constant regardless of strain
(D) Energy is fully recovered instantly
28. Stress relaxation means:
(A) Stress decreases under constant strain
(B) Strain decreases under constant stress
(C) Both stress and strain remain constant
(D) Stress and strain both increase
29. The toe region of stress-strain curve in tendon represents:
(A) Uncrimping of collagen fibers
(B) Plastic deformation
(C) Fracture
(D) Elastic limit
30. The linear region of tendon’s stress-strain curve corresponds to:
(A) Elastic behavior
(B) Plastic deformation
(C) Fracture point
(D) Relaxation
31. Stress in ligaments is mainly:
(A) Tensile
(B) Compressive
(C) Shear
(D) Rotational
32. Compressive stress in vertebrae mainly acts on:
(A) Intervertebral discs
(B) Muscles
(C) Ligaments
(D) Cartilage
33. Which tissue shows the highest stiffness?
(A) Tendon
(B) Bone
(C) Ligament
(D) Skin
34. Which tissue is most compliant (flexible)?
(A) Skin
(B) Tendon
(C) Bone
(D) Cartilage
35. The ratio of stress to strain in elastic region is:
(A) Young’s modulus
(B) Fracture strength
(C) Yield strength
(D) Toughness
36. The toughness of a tissue represents:
(A) Energy absorbed before failure
(B) Slope of elastic curve
(C) Resistance to elastic deformation
(D) Ratio of lateral to longitudinal strain
37. Which stress is most responsible for bone fractures during twisting?
(A) Tensile
(B) Compressive
(C) Shear
(D) Elastic
38. Fatigue failure of bone occurs due to:
(A) Repetitive stress below fracture limit
(B) Single high-impact stress
(C) Lack of tensile strength
(D) Lack of compression resistance
39. Which mechanical property describes resistance to permanent deformation?
(A) Strength
(B) Stiffness
(C) Ductility
(D) Elasticity
40. Which mechanical property describes ability to deform before fracture?
(A) Ductility
(B) Brittleness
(C) Stiffness
(D) Resilience
41. Which property describes ability to absorb energy and return to original shape?
(A) Resilience
(B) Stiffness
(C) Toughness
(D) Strength
42. Which mechanical property is most important in tendons?
(A) Tensile strength
(B) Compressive strength
(C) Shear resistance
(D) Torsional stiffness
43. Which mechanical property is most important in cartilage?
(A) Compressive strength
(B) Tensile strength
(C) Shear strength
(D) Torsion resistance
44. Which mechanical property is most important in ligaments?
(A) Tensile strength
(B) Compressive strength
(C) Shear strength
(D) Elastic modulus
45. Which factor affects stress-strain behavior of bone?
(A) Age
(B) Loading rate
(C) Geometry
(D) All of the above
46. The region between elastic limit and fracture is called:
(A) Plastic region
(B) Elastic region
(C) Resilience zone
(D) Recovery region
47. The stress corresponding to first permanent deformation is:
(A) Yield stress
(B) Fracture stress
(C) Ultimate stress
(D) Elastic modulus
48. Bone is anisotropic, meaning:
(A) Properties vary with direction of loading
(B) Properties remain same in all directions
(C) No stress-strain curve
(D) Deforms only under compression
49. Which property decreases most with osteoporosis?
(A) Compressive strength
(B) Tensile strength
(C) Elastic modulus
(D) All of the above
50. The ultimate failure point on stress-strain curve corresponds to:
(A) Fracture
(B) Yield
(C) Elastic limit
(D) Recovery