Engineering Questions with Answers - Multiple Choice Questions

# Strength of Materials MCQs Rankine’s Theory at Buckling Load and Crushing Load

1 - Question

Calculate the Euler’s crippling load, if the effective length of column is 10 m take flexural rigidity as 6.14 × 1010 Nmm2.
a) 6 kN
b) 8 kN
c) 10 kN
d) 12 kN

Explanation: To find P:
P = π2 × EI/L2
P = π2 × 6.14 ×1010 / 100002
P = 6.055 kN ~ 6 kN.

2 - Question

A fine grained material is mostly ________
a) Homogeneous
b) Isotropic
c) Isomeric
d) Elastic

Explanation: A material is said to be isotropic if at any point it has identical elastic properties in all directions. A fine grained material is mostly isotropic in nature.

3 - Question

The tangential force per unit area is _________
a) Shear strain
b) Shear stress
c) Modulus of rigidity
d) Torsion

Explanation: The tangential force acting along the section of the body is termed as shear force and the stress in the section due to shear force is called shear stress and it is denoted by fs.

4 - Question

Which of the following is also known as pushing force?
a) Tensile stress
b) Compressive stress
c) Shear stress
d) Temperature stress

Explanation: When an external force cause shortening of the body in the direction of the force it is termed as compressive force. The stress developed in the body due to the compressive force is called compressive stress.

5 - Question

Which of the following is also known as pulling force?
a) Tensile stress
b) Shear stress
c) Lateral stress
d) Axial stress

Explanation: When an external force produces elongation of the body in its direction, it is termed as a tensile force. The stress developed in a cross section of the body due to a tensile force is called tensile stress.

6 - Question

Longitudinal strain is also known as ___________
a) Direct strain
b) Axial strain
c) Indirect strain
d) Shear strain

Explanation: Direct strain is a measure of deformation produced by the application of the external forces. It is the ratio of change in dimension to the original dimension. It is also known as longitudinal strain.

7 - Question

Which of the following is also known as transverse strain?
a) Tensile strain
b) Compressive strain
c) Shear strain
d) Volumetric strain

Explanation: Shear Strain is a measure of the angle through which a body is this distorted with applied forces. Shear Strain is also known as the transverse strain.
Shear strain = ds/L.

8 - Question

The hooks law is valid only for _________
a) Uni axial forces
b) Bi axial forces
c) Tri axial forces
d) Lateral forces

Explanation: Hooke’s law: (Given by Sir Robert Hooke in 1678): stress is directly proportional to strain within limit of proportionality. It is valid for uniaxial force only.

9 - Question

Which of the following is also known as endurance limit?
a) Proportionality limit
b) Rupture limit
c) Elastic limit
d) Fatigue limit

Explanation: The greatest stress applied an infinite number of times that a material can take without causing Failure is known as endurance or fatigue limit.

10 - Question

The ultimate strength in flexure is known as modulus of ________
a) Toughness
b) Rupture
c) Resilience
d) Hardening

Explanation: The ultimate strength in flexure or torsion is known as modulus of rupture and the modulus of resilience is defined as the energy stored per unit volume at the elastic limit.

11 - Question

A material which ruptures with little or no plastic deformation is said to be ____________
a) Ductile material
b) Elastic material
c) Plastic material
d) Brittle material

Explanation: A material is said to be brittle, if it ruptures with little or no plastic deformation and a material said to be ductile if it undergoes deformation without rupture.

12 - Question

The stress which is just sufficient to cause a permanent set is known as ___________
a) tenacity
b) ultimate stress
c) proof stress
d) working stress

Explanation: Proof stress is a stress which is just sufficient to cause a permanent set equal to a specified percentage of the original gauge length. The stress corresponding to 0.2% of strain in the stress strain curve of mild steel is also known as proof stress.

13 - Question

For engineering materials, the poison’s ratio lies in the range of ___________
a) 0 and 1
b) -1 and 1
c) -2 and 2
d) 0 and 1/2

Explanation: The ratio of lateral strain to the corresponding longitudinal or linear strain is called poison’s ratio and it is denoted by 1 / m. The value of poison’s ratio for elastic materials usually lies between 0.25 and 0.33 in no case the value doesn’t exceed 0.5.

14 - Question

For ductile materials, the factor of safety is the ratio of yield stress to ___________
a) tenacity
b) ultimate stress
c) working stress
d) shear stress

Explanation: Factor of safety,; for ductile materials, F.O.S = yield stress/Working stress
For brittle materials; F.O.S = ultimate stress / working stress.

15 - Question

A material having three mutually perpendicular planes of elastic symmetry is said to be _________
a) Isotropic
b) Autotrophic
c) Orthotropic
d) Anisotropic