# Mechanics of Structures

### CE3I

#### 22303

##### Multiple Choice Questions (MCQs)
1   The axis passing through the center of gravity of a section is called
(A)   Centroidal axis
(B)   X-X axis
(C)   Y-Y axis
(D)   All of the above

2   Moment of inertia is a________ moment of area
(A)   First
(B)   Second
(C)   Infinite
(D)   Zero

3   Radius of gyration is expressed as.
(A)   N
(B)   kN
(C)   mm
(D)   kN-m

4   Moment of inertia of quarter circle is
(A)   0.11 R4
(B)   0.055 R4
(C)   0.55 R2
(D)   0.011 R4

5   The moment of inertia of plane section about any axis parallel to the centroidal axis is equal to the moment of inertia of the section about the centroidal axis plus the product of the area of the section and the square of the distance between the two axes is a
(A)   Perpendicular axis theorem
(B)   Polar axis theorem
(C)   Parallel axis theorem
(D)   All the above

6   Polar moment of inertia is expressed as (Ixx=moment of inertia about X-X axis, Iyy = moment of inertia about Y-Y axis)
(A)   Ixx+Iyy
(B)   Ixx+Izz
(C)   Ixx-Iyy
(D)   Ixx/Iyy

7   Calculate moment of inertia of a circular section having 50 mm diameter
(A)   306.79×103 mm4
(B)   308.7×104 mm4
(C)   311.20×104 mm4
(D)   364.20×104 mm4

8   Stress is a
(A)   External force
(B)   Internal resisting force
(C)   Axial force

9   When tensile stress is applied axially on a circular rod its
(A)   Diameter decreases and length also decreases
(B)   Diameter decreases and length increases
(C)   Diameter increases and volume decreases
(D)   Length decreases

10   Tensile strain is
(A)   Increase in length /Original length
(B)   Decrease in length/ Original length
(C)   Change in volume / Original volume
(D)   All of the above

11   Hooke’s law is applicable within
(A)   Elastic limit
(B)   Plastic limit
(C)   Fracture point
(D)   Ultimate strength

12   Modulus of rigidity is
(A)   Tensile stress / Tensile strain
(B)   Shear stress / Shear strain
(C)   Tensile stress / Shear strain
(D)   Shear stress / Tensile strain

13   A rod, 120cm long and diameter 3 cm is subjected to an axial pull of 18kN. The stress in N/mm2 is
(A)   22.57
(B)   23.47
(C)   24.57
(D)   25.47

14   Which of the following is not a basic type of strain
(A)   Compressive strain
(B)   Shear strain
(C)   Area strain
(D)   Volume strain

15   Double shear is a (A- Area of cross section, P- Load)
(A)   P/2A
(B)   2P/A
(C)   2P/2A
(D)   P/A

16   Bulk modulus of elasticity is
(A)   Tensile stress/Tensile strain
(B)   Shear stress / Shear strain
(C)   Tensile stress/ Shear strain
(D)   Nominal stress on each face of cube / volumetric strain

17   Poisson’s ratio is
(A)   Lateral strain to linear strain
(B)   Shear strain to lateral strain
(C)   Linear strain to lateral strain
(D)   Lateral strain to volumetric strain

18   Modulus of elasticity is
(A)   Strain /stress
(B)   stress/strain
(C)   Stress-strain
(D)   Stress x strain

19   The relationship between modulus of elasticity (E), Bulk modulus (K) and Poisson’s ratio (u) is given by
(A)   E=2K(1-u)
(B)   E=3K(1-2u)
(C)   E=2K(1-3u)
(D)   E=3K(1-u)

20   The deformation per unit length is called as
(A)   Strain
(B)   Stress
(C)   Elasticity
(D)   Plasticity

21   Which of the following material is more elastic
(A)   Rubber
(B)   Glass
(C)   Steel
(D)   Wood

22   Young modulus of certain metal is 120kN/mm2, if Poisson’s ratio is 0.29. Find the value of modulus of rigidity
(A)   44.51 kN/mm2
(B)   46.512 kN/mm2
(C)   40.12 kN/mm2
(D)   47.512 kN/mm2

23   % elongation of bar is calculated as
(A)   (Increase in length/ Original length) x 100
(B)   (Increase in length/ Decrease in length) x 100
(C)   (Original length/ Increase in length) x 100
(D)   (Original length/ Decrease in length) x 100

24   Find temperature stress if rod is heated through 60⁰, Coefficient of linear expansion=12×102-6/⁰c and E=2.1×105N/mm2
(A)   128.2 N/mm2
(B)   151.2 N/mm2
(C)   204.2 N/mm2
(D)   32k N/mm2

25   A bar of c/s area mm2 is axially pulled by a force ‘P’ kN. If the maximum stress induced in the bar is 30mpa, determine ‘P’.
(A)   3 kN
(B)   2 kN
(C)   0.4 kN
(D)   6 kN

26   Biaxial lateral strain Mpa, determine is
(A)   ey=1/E(σy-uσx)
(B)   ey=1/E(uσy-uσx)
(C)   ey=1/E(uσy-σx)
(D)   None of the above

27   Relation between bulk modulus (K), Poisson’s ratio (u), 27. modulus of rigidity(G), Modulus of elasticity (E) is
(A)   E=6KG/G=3K
(B)   E=9KG/G+3K
(C)   E=KG/9G+3K
(D)   E=2KG/G+K

28   The stress-strain curve for a mild steel is straight line up to
(A)   Yield point
(B)   Proportional limit
(C)   Elastic limit
(D)   all of the above