Strength of Material MCQ Set 9
STRENGTH OF MATERIAL MCQ SET 9
Q1. Rankine’s formula combines the effect of:
A) Bending and torsion
B) Direct stress and bending
C) Crushing and buckling
D) Shear and torsion
Show Answer
Answer: C) Crushing and buckling
Explanation: Rankine’s formula is a semi-empirical relation covering both short and long column failures.
Q2. The unit of strain energy is:
A) N/m
B) N/m²
C) Joule
D) N
Show Answer
Answer: C) Joule
Explanation: Strain energy is a form of energy stored, hence measured in Joules.
Q3. Strain energy per unit volume is called:
A) Resilience
B) Elasticity
C) Modulus
D) Stiffness
Show Answer
Answer: A) Resilience
Explanation: Resilience = energy stored per unit volume within elastic limit.
Q4. Modulus of resilience is numerically equal to:
A) σ²/2E
B) σ/E
C) σ²/E
D) 2E/σ²
Show Answer
Answer: A) σ²/2E
Explanation: The area under the linear portion of stress-strain curve gives modulus of resilience.
Q5. The energy stored due to bending in a beam is called:
A) Strain energy
B) Bending energy
C) Torsional energy
D) Deflection energy
Show Answer
Answer: A) Strain energy
Explanation: Bending induces strain energy due to bending stress distribution.
Q6. Thermal stress occurs when:
A) Body is free to expand
B) Body is restrained from expansion
C) Temperature is constant
D) None
Show Answer
Answer: B) Body is restrained from expansion
Explanation: When expansion is restricted, temperature change induces internal stresses.
Q7. The formula for thermal stress is:
A) σ = EαΔT
B) σ = αΔT/E
C) σ = E/αΔT
D) σ = αE/ΔT
Show Answer
Answer: A) σ = EαΔT
Explanation: Thermal stress = modulus × coefficient of expansion × temperature change.
Q8. A composite bar means:
A) Same material
B) Different materials joined together
C) Same cross-section
D) Equal stresses
Show Answer
Answer: B) Different materials joined together
Explanation: Composite bars consist of dissimilar materials rigidly connected to act together.
Q9. In a composite bar under temperature change, the stress depends on:
A) α and E of both materials
B) Only α
C) Only E
D) None
Show Answer
Answer: A) α and E of both materials
Explanation: Both modulus and thermal expansion coefficient affect the induced stresses.
Q10. The shear stress on a plane parallel to principal plane is:
A) Maximum
B) Minimum
C) Zero
D) Infinite
Show Answer
Answer: C) Zero
Explanation: Shear stress on principal planes is always zero.