### Civil Engineering - Strength of Materials MCQs Part 4

1. The bending moment is maximum on a section where shearing force

A.
is maximum
B.
is minimum
C.
is equal
D.
changes sign.

2. Pick up the correct statement from the following :

A.
The rate of change of bending moment is equal to rate of shear force
B.
The rate of change of shear force is equal to rate of loading
C.
neither (a) nor (b)
D.
both (a) and (b).

3. A short masonry pillar is 60 cm x 60 cm in cross-section, the core of the pillar is a square whose side is

A.
17.32 cm
B.
14.14 cm
C.
20.00 cm
D.
22.36 cm
E.
25.22 cm.

4. A rectangular log of wood is floating in water with a load of 100 N at its centre. The maximum shear force in the wooden log is

A.
50 N at each end
B.
50 N at the centre
C.
100 N at the centre
D.
none of these.

5. The following assumption is not true in the theory of pure torsion :

A.
The twist along the shaft is uniform
B.
The shaft is of uniform circular section throughout
C.
Cross-section of the shaft, which is plane before twist remains plane after twist
D.
All radii get twisted due to torsion.

6. The under mentioned type is simple strain

A. tensile strain
B. compressive strain
C. shear strain
D. volumetric strain
E. all the above.

7. The ratio of the effective length of a column and minimum radius of gyration of its cross-sectional area, is known

A. buckling factor
B. slenderness ratio
C. crippling factor
D. none of these.

8. The bending moment at C of a portal frame shown in below figure is(1st distance 4m)

A. 8 t-m
B. 4 t-m
C. 28 t-m
D. 16 t-m
E. zero.

9. Failure of riverted joints is due to

A. Tearing of the plates between the rivet hole and the edge of the plate
B. Tearing of plates between rivets
C. Shearing of rivets
D. Crushing of rivets
E. All the above.

10. The maximum load to which a fillet joint of length L can be subjected to, is

A. 0.7 x S x fillet size x L
B. 2 x S x fillet size x L
C. permissible shear stress x fillet size x L
D.
E. none of these.

11. Pick up the correct assumption of the theory of simple bending

A. The value of the Young's modulus is the same in tension as well as in compression
B. Transverse section of a beam remains plane before and after bending
C. The material of the beam is homogeneous and isotropic
D. The resultant pull or thrust on transverse section of a beam is zero
E. All the above.

12. The neutral axis of a beam cross-section must

A. pass through the centroid of the section
B. be equidistant from the top of bottom films
C. be an axis of symmetry of the section
D. none of these.

13. If the beam is supported so that there are only three unknown reactive elements at the supports. These can be determined by using the following fundamental equation of statics

A. ∑H = 0
B. ∑V = 0
C. ∑H = 0; ∑H = 0
D. ∑H = 0; ∑V = 0; ∑M = 0
E. ∑M = 0; ∑H = 0

14. In a solid arch, shear force acts

A. vertically upwards
B. along the axis of the arch
C. perpendicular to the axis of arch
D. tangentially to the arch
E. none of these.

15. A three hinged arch is loaded with an isolated load 1000 kg at a horizontal distance of 2.5 m from the crown, 1 m above the level of hinges at the supports 10 metres apart. The horizontal thrust is

A. 1250 kg
B. 125 kg
C. 750 kg
D. 2500 kg
E. 2325 kg.

16. For keeping the stress wholly compressive the load may be applied on a circular column anywhere within a concentric circle of diameter

A. d/2
B. d/3
C. d/4
D. d/8
E. d/10

17. A member is balanced at its end by two inclined members carrying equal forces. For equilibrium the angle between the inclined bars must be

A. 3°
B. 45°
C. 60°
D. 90°
E. 120°

18. For a cantilever with a uniformly distributed load W over its entire length L, the maximum bending moment is

A. WL
B. WL
C. WL
D. W2L
E. WL2

19. To ascertain the maximum permissible eccentricity of loads on circular columns, the rule generally followed, is

A. middle half rule of columns
B. middle third rule of columns
C. middle fourth rule of columns
D. none of these.

20. If Z and I are the section modulus and moment of inertia of the section, the shear force F and bending moment M at a section are related by

A.
B.
C.
D.

21. A closely coiled helical spring of radius R, contains n turns and is subjected to an axial load W. If the radius of the coil wire is r and modulus of rigidity of the coil material is C, the deflection of the coil is

A.
B.
C.
D.

22. The width of a beam of uniform strength having a constant depth d length L, simply supported at the ends with a central load W is

A.
B.
C.
D.

23. Beams of uniform strength are preferred to those of uniform section because these are economical for

A. large spans
B. heavy weights
C. light weights
D. short spans.

24. The moment diagram for a cantilever whose free end is subjected to a bending moment, will be a

A. triangle
B. rectangle
C. parabola
D. cubic parabola.

25. Reactions at the supports of a structure can be determined by equating the algebraic sum of

A. horizontal forces to zero
B. vertical forces to zero
C. moment about any point to zero
D. all the above.

26. If a steel rod of 20 mm diameter and 5 metres long elongates by 2.275 mm when subjected to an axial pull of 3000 kg, the stress developed, is

A. 9.5541 kg/cm2
B. 95.541 kg/cm2
C. 955.41 kg/cm2
D. 9554.1 kg/cm2.

27. Shear force for a cantilever carrying a uniformly distributed load over its length, is

A. triangle
B. rectangle
C. parabola
D. cubic parabola.

28. If the width of a simply supported beam carrying an isolated load at its centre is doubled, the deflection of the beam at the centre is changed by

A. 2 times
B. 4 times
C. 8 times
D. 1/2 times
E. 3 times.

29. For a stable frame structure, number of members required, is

A. three times the number of joints minus three
B. twice the number of joints minus three
C. twice the number of joints minus two
D. twice the number of joints minus one
E. none of these.

30. When a rectangular beam is loaded transversely, the maximum compressive stress develops on

A. bottom fibre
B. top fibre
C. neutral axis
D. every cross-section.

31. The maximum deflection of a simply supported beam of length L with a central load W, is

A.
B.
C.
D.
E.

32. In a continuous bending moment curve the point where it changes sign, is called

A. point of inflexion
B. point of contraflexture
C. point of virtual hinge
D. all the above.

33. A beam of length L supported on two intermediate rollers carries a uniformly distributed load on its entire length. If sagging B.M. and hogging B.M. of the beam are equal, the length of each overhang, is

A. 0.107 L
B. 0.207 L
C. 0.307 L
D. 0.407 L
E. 0.5 L.

34. A long vertical member, subjected to an axial compressive load, is called

A. a column
B. a strut
C. a tie
D. a stanchion
E. all the above.

35. The property by which a body returns to its original shape after removal of the force, is called

A. plasticity
B. elasticity
C. ductility
D. malleability.

36. The ratio of the maximum deflection of a cantilever beam with an isolated load at its free end and with a uniformly distributed load over its entire length, is

A. 1
B.
C.
D.
E.

37. For a beam of uniform strength keeping its depth constant, the width will vary in proportion to

A. bending moment (M)
B. M
C. M2
D. none of these.

38. A shaft 9 m long is subjected to a torque 30 t-m at a point 3 m distant from either end. The reactive torque at the nearer end will be

A. 5 tonnes metre
B. 10 tonnes metre
C. 15 tonnes metre
D. 20 tonnes metre
E. none of these.

39. The width b and depth d of a beam cut from a wooden cylindrical log of 100 cm diameter for maximum strength are :

A. b = 57.73 cm d = 81.65 cm
B. b = 81.65 cm d = 57.73 cm
C. b = 50.00 cm d = 50.00 cm
D. b = 40.00 cm d = 80.00 cm
E. b = 30.00 cm d = 60.00 cm.

40. If the stress produced by a prismatic bar is equal to the working stress, the area of the cross-section of the prismatic bar, becomes

A. zero
B. infinite
C. maximum
D. minimum.

41. The section modulus of a rectangular section is proportional to

A. area of the section
B. square of the area of the section
C. product of the area and depth
D. product of the area and width
E. half moment of inertia of the section.

42. The property of a material by which it can be drawn to a smaller section, due to tension, is called

A. plasticity
B. ductility
C. elasticity
D. malleability.

43. The distance between the centres of adjacent rivets in the same row, is called

A. pitch
B. lap
C. gauge
D. staggered pitch.

44. Shear deflection of a cantilever of length L, cross sectional area A and shear modulus G, subjected to w/m u.d.l., is

A.
B.
C.
D.

45. 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
E. none of the these.

46. As the elastic limit reaches, tensile strain

A. increases more rapidly
B. decreases more rapidly
C. increases in proportion to the stress
D. decreases in proportion to the stress.

47. The ratio of the flexural strengths of two square beams one placed with its two sides horizontal and the other placed with one diagonal vertical, diagonal, is

A. 2
B. 2
C. 5
D. 7

48. Simple bending equation is

A.
B.
C.
D.
E. none of these.

49. Every material obeys the Hooke's law within its

A. elastic limit
B. plastic point
C. limit of proportionality
D. none of these.

50. The maximum compressive stress at the top of a beam is 1600 kg/cm2 and the corresponding tensile stress at its bottom is 400 kg/cm2 . If the depth of the beam is 10 cm, the neutral axis from the top, is

A. 2 cm
B. 4 cm
C. 6 cm
D. 8 cm
E. 10 cm.