Strength of Materials (SS)

Q:   The Poisson's ratio for a perfectly incompressible linear elastic material is

• A:  1
• B:  0.5
• C:  0
• D:  infinity

Q:   In the engineering stress-strain curve for mild steel, the Ultimate Tensile Strength (UTS) refers to

• A:  Yield stress
• B:  Proportional limit
• C:  Maximum stress
• D:  Fracture stress

Q:   A helical compression spring made of wire of circular cross-section is subjected to a compressive load. The maximum shear stress induced in the cross-section of the wire is 24 MPa. For the same compressive load, if both the wire diameter and the mean coil diameter are doubled, the maximum shear stress (in MPa) induced in the cross-section of the wire is _____.

Q:   The deflection of a spring with 20 active turns under a load of 1000 N is 10 mm. The spring is made into two pieces each of 10 active coils and placed in parallel under the same load. The deflection of the system is

• A:  20mm
• B:  10mm
• C:  5mm
• D:  2.5mm

Q:   A cantilever beam with square cross-section of 6 mm side is subjected to a load of 2kN normal to the top surface as shown in figure. The Young’s modulus of elasticity of the material of the beam is 210 GPa. The magnitude of slope (in radian) at Q (20 mm from the fixed end) is ________

Q:   A thin cylindrical pressure vessel with closed-ends is subjected to internal pressure. The ratio of circumferential (hoop) stress to the longitudinal stress is

• A:  0.25
• B:  0.5
• C:  1
• D:  2

Q:   A cylindrical tank with closed ends is filled with compressed air at a pressure of 500kPa. The inner radius of the tank is 2m, and it has wall thickness of 10mm. The magnitude of maximum in-plane shear stress (in MPa) is ________

Q:   Consider a simply supported beam of length 50h, with a rectangular cross-section of depth h, and width 2h. The beam carries a vertical point load P, at its mid-point. The ratio of the maximum shear stress to the maximum bending stress in the beam is

• A:  0.02
• B:  0.1
• C:  0.05
• D:  0.01

Q:   A long thin walled cylindrical shell, closed at both the ends, is subjected to an internal pressure. The ratio of the hoop stress (circumferential stress) to longitudinal stress developed in the shell is

• A:  0.5
• B:  1
• C:  2
• D:  4

Q:   Two threaded bolts A and B of same material and length are subjected to identical tensile load. If the elastic strain energy stored in bolt A is 4 times that of bolt B and the mean diameter of bolt A is 12 mm, the mean diameter of bolt B in mm is

• A:  16
• B:  24
• C:  36
• D:  48