Exam 2026–2027 | Full-Length
Questions, Answers & Detailed
Rationales
Q1.
A prismatic steel bar has a cross-sectional area of 2,000 mm² and carries an axial
tensile load of 180 kN. What is the average normal stress in the bar?
A. 45 MPa
B. 60 MPa
C. 90 MPa
D. 120 MPa
Answer: 90 MPa
Rationale: Normal stress is σ = P/A. Thus, σ = 180,000 N / 2,000 mm² = 90
N/mm² = 90 MPa.
Q2.
,A 3.0-m-long steel rod with a cross-sectional area of 600 mm² carries an axial
tensile load of 120 kN. If E = 200 GPa, what is the elongation?
A. 0.75 mm
B. 1.50 mm
C. 3.00 mm
D. 6.00 mm
Answer: 3.00 mm
Rationale: Axial deformation is δ = PL/(AE). Substituting the values gives δ =
(120,000)(3,000)/(600)(200,000) = 3.0 mm.
Q3.
A steel specimen is subjected to a uniaxial tensile stress of 160 MPa. If the
modulus of elasticity is 200 GPa, what is the corresponding normal strain?
A. 0.0004
B. 0.0008
C. 0.0010
D. 0.0016
Answer: 0.0008
Rationale: Hooke's law gives ε = σ/E = 160 MPa / 200,000 MPa = 0.0008.
Q4.
A rectangular beam has a width of 150 mm and a depth of 300 mm. What is its
elastic section modulus about the centroidal horizontal axis?
A. 1.125 × 10⁶ mm³
B. 2.25 × 10⁶ mm³
,C. 3.375 × 10⁶ mm³
D. 4.50 × 10⁶ mm³
Answer: 2.25 × 10⁶ mm³
Rationale: I = bh³/12 = 150(300³)/12 = 337.5 × 10⁶ mm´. The section modulus is S
= I/c = 337.5 × 10⁶/150 = 2.25 × 10⁶ mm³.
Q5.
A beam section has a moment of inertia of 8.0 × 10⁶ mm´ and an extreme-fiber
distance of 200 mm. If the bending moment is 24 kN·m, what is the maximum
bending stress?
A. 300 MPa
B. 150 MPa
C. 600 MPa
D. 75 MPa
Answer: 600 MPa
Rationale: The flexure formula is σ = Mc/I. Therefore, σ = (24 × 10⁶)(200)/(8 ×
10⁶) = 600 MPa.
Q6.
For a homogeneous rectangular beam subjected to pure positive bending, where
is the longitudinal bending stress zero?
A. At the top surface
B. At the bottom surface
C. At the neutral axis
D. At the centroid only
Answer: At the neutral axis
, Rationale: The bending stress varies linearly with distance from the neutral axis
and is zero at the neutral axis.
Q7.
A 250-mm-wide rectangular beam is 500 mm deep. If the bending moment is 100
kN·m, what is the maximum bending stress?
A. 2.4 MPa
B. 4.8 MPa
C. 9.6 MPa
D. 19.2 MPa
Answer: 9.6 MPa
Rationale: I = bh³/12 = 250(500³)/12 = 2.604 × 10⁹ mm´. With c = 250 mm, σ =
Mc/I = (100 × 10⁶)(250)/(2.604 × 10⁹) ≈ 9.6 MPa.
Q8.
A solid circular shaft has diameter 80 mm. What is its polar moment of inertia?
A. 1.61 × 10⁶ mm´
B. 3.22 × 10⁶ mm´
C. 6.43 × 10⁶ mm´
D. 12.86 × 10⁶ mm´
Answer: 3.22 × 10⁶ mm⁴
Rationale: For a solid circular shaft, J = πd´/32. Substituting d = 80 mm gives J ≈
3.22 × 10⁶ mm´.
Q9.