SOM Questions for AE Exams
Strength of Materials (SOM) Questions for AE Exams
Exam Pattern:
• 1 mark for each correct answer
• 0.25 negative marking for wrong answers
• Questions similar AE level exams
1. The ratio of lateral strain to longitudinal strain is known as:
A) Young's modulus
B) Bulk modulus
C) Poisson's ratio
D) Modulus of rigidity
Correct Answer: C) Poisson's ratio
Poisson's ratio is defined as the ratio of lateral strain to longitudinal strain when a material is stretched.
2. For a simply supported beam with central point load, the maximum bending moment occurs at:
A) Supports
B) Quarter span
C) Mid span
D) Throughout the beam
Correct Answer: C) Mid span
For a simply supported beam with central point load, the maximum bending moment occurs at the mid span.
3. The unit of modulus of elasticity is same as that of:
A) Stress
B) Strain
C) Force
D) Pressure
Correct Answer: A) Stress
Modulus of elasticity (E) = Stress/Strain, hence its unit is same as stress (N/mm² or Pa).
4. A column of length 'L' with both ends fixed has effective length:
A) L
B) L/2
C) 2L
D) L/√2
Correct Answer: B) L/2
For a column with both ends fixed, the effective length is L/2.
5. The bending stress in a beam is:
A) Directly proportional to the distance from neutral axis
B) Inversely proportional to the distance from neutral axis
C) Constant throughout the cross-section
D) Zero at the extreme fibers
Correct Answer: A) Directly proportional to the distance from neutral axis
Bending stress (σ) = (M*y)/I, where y is distance from NA. Hence, σ ∝ y.
6. The maximum shear stress in a solid circular shaft subjected to torsion is:
A) At the center
B) At the surface
C) Uniform throughout
D) At quarter radius
Correct Answer: B) At the surface
Shear stress in circular shaft varies linearly from zero at center to maximum at surface.
7. The moment of inertia of a rectangular section about its base is:
A) bd³/3
B) bd³/12
C) db³/3
D) db³/12
Correct Answer: A) bd³/3
For rectangle about its base, I = bd³/3 (where b=width, d=depth).
8. The shape of shear stress distribution diagram for a rectangular beam is:
A) Rectangular
B) Triangular
C) Parabolic
D) Circular
Correct Answer: C) Parabolic
Shear stress distribution in rectangular beam is parabolic with maximum at neutral axis.
9. The maximum deflection of a cantilever beam carrying a point load at free end is:
A) WL³/3EI
B) WL³/8EI
C) WL³/16EI
D) WL³/48EI
Correct Answer: A) WL³/3EI
Maximum deflection for cantilever with end load is WL³/3EI at free end.
10. The polar moment of inertia of a solid circular shaft of diameter D is:
A) πD⁴/16
B) πD⁴/32
C) πD⁴/64
D) πD³/16
Correct Answer: B) πD⁴/32
Polar moment of inertia J = πD⁴/32 for solid circular section.
11. The Euler's buckling load for a column with one end fixed and other end free is:
A) π²EI/L²
B) π²EI/4L²
C) 2π²EI/L²
D) 4π²EI/L²
Correct Answer: B) π²EI/4L²
For fixed-free column, effective length = 2L, so Pcr = π²EI/(2L)² = π²EI/4L².
12. The strain energy stored in a body due to shear stress is given by:
A) τ²/2G
B) τ/2G
C) τ²/G
D) τ/G
Correct Answer: A) τ²/2G
Strain energy per unit volume in shear = τ²/2G, where G is modulus of rigidity.
13. A beam is said to be of uniform strength if:
A) Bending moment is same at all sections
B) Shear force is same at all sections
C) Deflection is same at all sections
D) Maximum bending stress is same at all sections
Correct Answer: D) Maximum bending stress is same at all sections
Uniform strength beam has same maximum bending stress at all cross-sections.
14. The slenderness ratio of a column is defined as the ratio of:
A) Length to radius of gyration
B) Radius of gyration to length
C) Effective length to least lateral dimension
D) Least lateral dimension to effective length
Correct Answer: A) Length to radius of gyration
Slenderness ratio = Effective length / Least radius of gyration.
15. The maximum deflection of a simply supported beam carrying UDL over entire span is:
A) 5wL⁴/384EI
B) wL⁴/8EI
C) wL⁴/384EI
D) wL⁴/48EI
Correct Answer: A) 5wL⁴/384EI
Maximum deflection for simply supported beam with UDL is 5wL⁴/384EI at center.
16. The neutral axis of a beam under bending stresses:
A) Experiences maximum stress
B) Experiences zero stress
C) Experiences minimum stress
D) Experiences shear stress only
Correct Answer: B) Experiences zero stress
Neutral axis is the layer where bending stress is zero.
17. The modulus of rigidity is defined as the ratio of:
A) Longitudinal stress to longitudinal strain
B) Shear stress to shear strain
C) Volumetric stress to volumetric strain
D) Lateral strain to longitudinal strain
Correct Answer: B) Shear stress to shear strain
Modulus of rigidity (G) = Shear stress (τ) / Shear strain (γ).
18. The bending moment diagram for a cantilever beam with UDL is:
A) Rectangular
B) Triangular
C) Parabolic
D) Cubic
Correct Answer: C) Parabolic
BMD for cantilever with UDL is parabolic (second degree curve).
19. The maximum shear stress theory is also known as:
A) Rankine's theory
B) Guest's theory
C) Saint Venant's theory
D) Mohr's theory
Correct Answer: B) Guest's theory
Maximum shear stress theory is also called Guest's or Tresca's theory.
20. The ratio of maximum shear stress to average shear stress in a rectangular beam is:
A) 1.0
B) 1.5
C) 2.0
D) 2.5
Correct Answer: B) 1.5
For rectangular section, τmax = 1.5 × τavg.
21. The point of contraflexure occurs in:
A) Simply supported beams
B) Cantilever beams
C) Overhanging beams
D) Fixed beams
Correct Answer: C) Overhanging beams
Point of contraflexure (where BM changes sign) occurs in overhanging beams.
22. The bulk modulus is defined as the ratio of:
A) Direct stress to direct strain
B) Shear stress to shear strain
C) Volumetric stress to volumetric strain
D) Lateral strain to linear strain
Correct Answer: C) Volumetric stress to volumetric strain
Bulk modulus (K) = Volumetric stress / Volumetric strain.
23. The maximum bending moment for a simply supported beam with UDL occurs at:
A) Supports
B) Quarter points
C) Mid span
D) Throughout the beam
Correct Answer: C) Mid span
For simply supported beam with UDL, maximum BM occurs at mid span.
24. The moment of inertia of a triangular section about its base is:
A) bh³/12
B) bh³/36
C) bh³/24
D) bh³/48
Correct Answer: A) bh³/12
For triangle about its base, I = bh³/12 (b=base, h=height).
25. The torsional rigidity of a shaft is given by:
Correct Answer: B) GJ
Torsional rigidity = G × J, where G=modulus of rigidity, J=polar moment of inertia.
