Structural Mechanics MCQ Questions and Answers in Civil Engineering

Question: Which type of load is applied in tensile testing?
a) Axial load
b) Shear load
c) Transverse load
d) Longitudinal load

Answer: c

Question: What is parallel axis theorem and to whom it is applied?
a) Theorem used to add the two mutually perpendicular moment of inertias for areas
b) Theorem used to add the two mutually perpendicular moment of inertias for volumes
c) Theorem used to add the two mutually perpendicular moment of inertias
d) Theorem used to add the two mutually perpendicular moment of inertias for vectors

Answer: a

Question: Consider a 250mmx15mmx10mm steel bar which is free to expand is heated from 150C to 400c. what will be developed?
a) Compressive stress
b) Tensile stress
c) Shear stress
d) No stress

Answer: d

Question: The maximum strain energy that can be stored in a body is known as
a) impact energy
b) resilience
c) proof resilience
d) modulus of resilience

Answer: c

Question: A 10 m long mild steel rail section is fixed at 300 K temperature. If temperature increases by 60 K, find stress in rail section if ends are not yielded. Coefficient of thermal expansion is 12 × 10 - 6 / K.
a) 72 N/mm2
b) 144 N/mm2
c) 120 N/mm2
d) 240 N/mm2

Answer: b

Question: What is the formula of theorem of parallel axis?
a) Iab = Ig + ah
b) Iab = ah2 + Ig
c) Iab = Ig – ah2
d) Izz = Iyy + Ixx

Answer: b

Question: Moment of inertia of any section about an axis passing through its C.G is
a) Maximum
b) Minimum
c) Depends upon the dimensions of the section
d) Depends upon the shape of the section

Answer: b

Question: which of the following has same unit?
a) modulus of elasticity, pressure, stress
b) elasticity, strain, stress
c) pressure, strain, stress
d) modulus of elasticity, strain, modulus of rigidity

Answer: a

Question: Young's modulus is defined as the ratio of
a) volumetric stress and volumetric strain
b) lateral stress and lateral strain
c) longitudinal stress and longitudinal strain
d) shear stress to shear strain

Answer: a

Question: The materials having same elastic properties in all directions are called
a) ideal materials
b) uniform materials
c) isotropic materials
d) elastic materials.

Answer: d

Question: Maximum deflection of a cantilever due to pure bending moment M at its free end, is
a) ML2/3EI
b) ML2/4EI
c) ML2/6EI
d) ML2/2EI

Answer: d

Question: The radius of gyration of a squar section is not proportional to
a) square root of the moment of inertia
b) square root of the inverse of the area
c) square root of the moment of inertia divided by area of the section
d) side of squar

Answer: d

Question: Pure bending of beam will have
a) Tensile and shear stresses
b) Compressive and shear stresses
c) Tensile and compressive stresses
d) None

Answer: c

Question: On bending of a beam, which is the layer which is neither elongated nor shortened?
a) Axis of load
b) Neutral axis
c) Center of gravity
d) None of the mentioned

Answer: d

Question: For any part of a beam between two concentrated load, Bending moment diagram is a
a) Horizontal straight line
b) Vertical straight line
c) Line inclined to x-axis
d) Parabola

Answer: c

Question: In a cantilever subjected to a combination of concentrated load, uniformly distributed load and uniformly varying load, Maximum bending moment is
a) Where shear force=0
b) At the free end
c) At the fixed end
d) At the mid-point

Answer: c

Question: A sudden increase or decrease in shear force diagram between any two points indicates that there is
a) No loading between the two points
b) Point loads between the two points
c) U.D,L. between the two points
d) None of these

Answer: b

Question: Sagging, the bending moment occurs at the of the beam.
a) At supports
b) Mid span
c) Point of contraflexure
d) Point of emergence

Answer: b

Question: Where do the maximum BM occurs for the below diagram.
a) -54 kNm
b) -92 kNm
c) -105 kNm
d) – 65 kNm

Answer: c

Question: Positive/negative bending moments occur where shear force changes its sign.
a) Minimum
b) Zero
c) Maximum
d) Remains same

Answer: c

Question: A sudden jump anywhere on the Bending moment diagram of a beam is caused by
a) Couple acting at that point
b) Couple acting at some other point
c) Concentrated load at the point
d) Uniformly distributed load or Uniformly varying load on the beam

Answer: a

Question: In bending moment diagram, if no load acts between two sections, then it is represented by
a) horizontal line
b) inclined line
c) vertical line
d) all of the above

Answer: b

Question: Net force acting on the cross section of beam in bending is
a) Tensile
b) Compressive
c) Zero
d) None

Answer: c

Question: In a composite beam bending, strain at the common interface will be
a) Equal
b) Unequal
c) Zero
d) None

Answer: a

Question: Which law is also called as the elasticity law?
a) Bernoulli’s law
b) Stress law
c) Hooke’s law
d) Poisson’s law

Answer: c

Question: In the calculation of the radius of gyration, we use intensity of loadings. So whenever the distributed loading acts perpendicular to an area its intensity varies __________
a) Linearly
b) Non-Linearly
c) Parabolically
d) Cubically

Answer: a

Question: The Young‟s modulus of elasticity of a material is 2.5 times its modulus of rigidity. The Poisson‟s ratio for the material will be
a) 0.25
b) 0.33
c) 0.50
d) 0.75

Answer: a

Question: The energy absorbed in a body, when it is strained within the elastic limits, is known as
a) strain energy
b) resilience
c) proof resilience
d) modulus of resilience

Answer: a

Question: During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm2. Ultimate tensile strength of specimen is
a) 4 tonnes/cm2
b) 8 tonnes/cm2
c) 16 tonnes/cm2
d) 22 tonnes/cm2

Answer: b

Question: A bar 2 m long and 20 mm diameter is subjected to an axial pull of 125.6 KN. Due to this load, length increases by 4 mm and diameter reduce by 0.012 mm. Find Poison‟s ratio.
a) 0.2
b) 0.25
c) 0.3
d) 0.35

Answer: c

Question: What is the formula of theorem of perpendicular axis?
a) Izz = Ixx – Iyy
b) Izz = Ixx + Ah2
c) Izz – Ixx = Iyy
d) None of the above

Answer: c

Question: What is modular ratio?
a) ratio of deflection in each material
b) ratio of modulus of elasticity of bot h material
c) ratio of load acting in each section
d) all of above

Answer: c

Question: Strain is defined as the ratio of
a) change in volume to original volume
b) change in length to original length
c) change in cross-sectional area to original cross-sectional area
d) any one of the above

Answer: b

Question: If the radius of wire stretched by a load is doubled, then its Young's modulus will be
a) Doubled
b) Halved
c) become four times
d) remain unaffected

Answer: d

Question: Columns of given length, cross-section and material have different values of buckling loads for different end conditions. The strongest column is one whose
a) one end is fixed and other end is hinged
b) both ends are hinged or pin jointed
c) one end is fixed and the other end entirely free
d) both the ends are fixed

Answer: d

Question: Bending stresses in a beam vary
a) Linearly
b) Parabolically
c) Cubic variation
d) None

Answer: a

Question: Bending occurs due to the application of
a) Axial load
b) Lateral load
c) Torsional load
d) None

Answer: b

Question: For any part of a beam subjected to uniformly distributed load, Shear force diagram is
a) Horizontal straight line
b) Vertical straight line
c) Line inclined to x-axis
d) Parabola

Answer: c

Question: Point of contra-flexure is also called
a) Point of maximum Shear force
b) Point of maximum Bending moment
c) Point of inflexion
d) Fixed end

Answer: c

Question: When the bending moment is parabolic curve between two points, it indicates that there is
a) No loading between the two points
b) Point loads between the two points
c) U.d)L. between the two points
d) Uniformly varying load between the two points

Answer: c

Question: What is the maximum bending moment for simply supported beam carrying a point load “W” kN at its centre?
a) W kNm
b) W/m kNm
c) W×l kNm
d) W×l/4 kNm

Answer: d

Question: Determine the moment at fixed end
a) 40 kNm
b) 50 kNm
c) 60 kNm
d) 80 kNm

Answer: d

Question: What is the other name for a positive bending moment?
a) Hogging
b) Sagging
c) Inflation
d) Contra flexure

Answer: b

Question: What is the maximum shear force acting on the beam shown below.
a) 125 N
b) 200 N
c) 4000 N
d) 8000 N

Answer: b

Question: What is the product of sectional modulus and allowable bending stress called as?
a) Moment of inertia
b) Moment of rigidity
c) Moment of resistance
d) Radius of gyration

Answer: c

Question: Which is more stronger in bending equal area square or circular beam
a) Square beam
b) Circular beam
c) Both are equally strong
d) None

Answer: b

Question: In bending, neutral axis always is
a) Perpendicular to the centroidal axis
b) Coincides with the centroidal axis
c) Parallel to the centroidal axis
d) None

Answer: b

Question: The materials which have the same elastic properties in all directions are called __________
a) Isotropic
b) Brittle
c) Homogeneous
d) Hard

Answer: a

Question: Elongation of a bar of uniform cross section of length „L‟, due to its own weight „W‟ is given by
a) 2WL/E
b) WL/E
c) WL/2E
d) WL/3E

Answer: c

Question: The safe stress for a hollow steel column which carries an axial load of 2100 kN is 125 MN/m2. if the external diameter of the column is 30cm, what will be the internal diameter?
a) 25 cm
b) 26.19cm
c) 30.14 cm
d) 27.9 cm

Answer: b

Question: stress at which extension of material takes place more quickly as compared to increase in load is called
a) elastic point of the material
b) plastic point of the material
c) breaking point of the material
d) yielding point of the material

Answer: d

Question: Tensile strength of a material is obtained by dividing the maximum load during the test by the
a) area at the time of fracture
b) original cross-sectional area
c) average of (a) and (b)
d) minimum area after fracture

Answer: b

Question: Moment of inertia of a square of side 1 unit about an axis through its center of gravity, is .
a) 1
b) 1/12
c) 1/3
d) 1/4

Answer: b

Question: What is the unit of Radius of gyration?
a) mm
b) mm2
c) mm3
d) mm4

Answer: a

Question: 3.5 m long bar is under tensile load and due to that increase in length of bar is 1.75 mm then strain =
a) 0.0035
b) 0.0005
c) 0.002
d) 0.0175

Answer: c

Question: The unit of Young's modulus is
a) mm/mm
b) kg/cm
c) kg
d) kg/cm2

Answer: d

Question: Which of the following has no unit
a) kinematic viscosity
b) surface tension
c) bulk modulus
d) strain

Answer: c

Question: A long vertical member, subjected to an axial compressive load, is called
a) a column
b) a strut
c) a tie
d) a stanchion

Answer: a

Question: The direction of bending stresses is along the
a) Axial direction
b) Lateral direction
c) Inclined direction
d) None

Answer: a

Question: Bending occurs due to the application of
a) Load parallel to the axis of the beam
b) Load inclined to the axis
c) Load perpendicular to the axis
d) None

Answer: c

Question: In a cantilever carrying a uniformly varying load starting from zero at the free end, the Bending moment diagram is
a) A horizontal line parallel to x-axis
b) A line inclined to x-axis
c) Follows a parabolic law
d) Follows a cubic law

Answer: d

Question: At a point in a simply supported or overhanging beam where Shear force changes sign and = 0, Bending moment is
a) Maximum
b) Zero
c) Either increasing or decreasing
d) Infinity

Answer: a

Question: Shear stress in the beam acting on the cross section is
a) Normal to the cross section
b) Tangential to the cross section
c) Neither normal nor tangential
d) None

Answer: b

Question: In Fig. (a), slope of S.F.d between B and C will be
a) Zero
b) 10 kN
c) 15 kN
d) 20 kN

Answer: a

Question: The equivalent length of a column fixed at one end and free at the other end, is
a) 0.5L
b) 0.7L
c) L
d) 2L

Answer: d

Question: Brittle material beams need reinforcement on the
a) Tension side
b) Compression side
c) Shear side
d) None

Answer: a

Question: Net force acting on the cross section of beam in bending is
a) Tensile
b) Compressive
c) Shear
d) None

Answer: d

Question: Uniformly varying load between two sections in shear force diagram is represented by
a) cubic curve
b) inclined line
c) horizontal line
d) parabolic curve

Answer: d

Question: For any part of the beam, between two concentrated load Shear force diagram is a
a) Horizontal straight line
b) Vertical straight line
c) Line inclined to x-axis
d) Parabola

Answer: a

Question: Shear force diagram is representation of shear force plotted as ordinate.
a) Scalar
b) Aerial
c) Graphical
d) Statically

Answer: c

Question: curve is formed due to bending of overhanging beams.
a) Elastic
b) Plastic
c) Flexural
d) Axial

Answer: a