Civil Engineering - Strength of Materials MCQs Part 3

1. The ratio of the moments of resistance of a solid circular shaft of diameter D and a hollow shaft (external diameter D and internal diameter d), is

A.

B.

C.

D.

E.
none of these.

 Answer Option A

2. A cantilever carries is uniformly distributed load W over its whole length and a force W acts at its free end upward. The net deflection of the free end will be

A.
zero

B.
upward

C.
downward

D.
none of these.

 Answer Option B

3. The moment diagram for a cantilever carrying a concentrated load at its free end, will be

A.
triangle

B.
rectangle

C.
parabola

D.
cubic parabola.

 Answer Option A

4. In a shaft rotated by a couple, the shear force varies

A.
from zero at the centre to a maximum at the circumference

B.
from minimum at the centre of maximum at the circumference

C.
from maximum at the centre to zero at the circumference

D.
equally throughout the section

E.
none of these.

 Answer Option A

5. The section modulus of a rectangular light beam 25 metres long is 12.500 cm3. The beam is simply supported at its ends and carries a longitudinal axial tensile load of 10 tonnes in addition to a point load of 4 tonnes at the centre. The maximum stress in the bottom most fibre at the mid span section, is

A.
13.33 kg/cm2 tensile

B.
13.33 kg/cm2 compressive

C.
26.67 kg/cm2 tensile

D.
26.67 kg/cm2 compressive

E.
none of these.

 Answer Option C

6. The shape of the bending moment diagram over the length of a beam, carrying a uniformly increasing load, is always

A. linear

B. parabolic

C. cubical

D. circular.

 Answer Option C

7. When a rectangular beam is loaded longitudinally, shear develops on

A. bottom fibre

B. top fibre

C. middle fibre

D. every-horizontal plane.

 Answer Option D

8. The tension coefficient of any member is

A. force divided by the length

B. tension divided by the length

C. tension per unit area

D. tension in the member.

 Answer Option B

9. A steel rod of 2 cm diameter and 5 metres long is subjected to an axial pull of 3000 kg. If E = 2.1 x 106, the elongation of the rod will be

A. 2.275 mm

B. 0.2275 mm

C. 0.02275 mm

D. 2.02275 mm.

 Answer Option B

10. For a given material, if E, C, K and m are Young's modulus, shearing modulus, bulk modulus and poisson ratio, the following relation does not hold good

A.

B.

C.

D.

E.

 Answer Option C

11. If the width b and depth d of a beam simply supported with a central load are interchanged, the deflection at the centre of the beam will be changed in the ratio of

A. b/d

B. d/b

C. (d/b)2

D. (b/d)2

E. (b/d)3.

 Answer Option D

12. In the given below figure, the rivets with maximum stress, are :

A. 1 and 2

B. 1 and 3

C. 3 and 4

D. 2 and 4

 Answer Option D

13. The maximum stress intensity due to a suddenly applied load is x-times the stress intensity produced by the load of the same magnitude applied gradually. The value of x is

A. 1

B. 2

C. 3

D.

E.

 Answer Option B

14. For the beam shown in below figure, the maximum positive bending moment is nearly equal to negative bending moment when L1 is equal to

A. 1.0 L

B. 0.7 L

C. 0.5 L

D. 0.35 L.

 Answer Option D

15. Strain energy of a member may be equated to

A. average resistance x displacement

B. stress x strain x area of its cross-section

C. stress x strain x volume of the member

D. (stress)2 x volume of the member + Young's modulus E.

 Answer Option D

16. If the stress in each cross-section of a pillar is equal to its working stress, it is called

A. body of equal

B. body of equal section

C. body of equal strength

D. none of these.

 Answer Option C

17. A composite member shown in below figure was formed at 25°C and was made of two materials a and b. If the coefficient of thermal expansion of a is more than that of b and the composite member is heated upto 45°C, then

A. a will be in tension and b in compression

B. both will be in compression

C. both will be in tension

D. a will be in compression and b in tension.

 Answer Option D

18. The stress at which extension of a material takes place more quickly as compared to the increase in load, is called

A. elastic point

B. plastic point

C. breaking point

D. yielding point.

 Answer Option D

19. In a square beam loaded longitudinally, shear develops

A. on middle fibre along horizontal plane

B. on lower fibre along horizontal plane

C. on top fibre along vertical plane

D. equally on each fibre along horizontal plane

E. none of these.

 Answer Option D

20. Shear deflection of a cantilever of length L, cross sectional area A and shear modulus G, under a concentrated load W at its free end, is

A.

B.

C.

D.

 Answer Option C

21. The point of contraflexture occurs in

A. cantilever beams only

B. continuous beams only

C. over hanging beams only

D. all types of beams

E. both (a) and (b).

 Answer Option C

22. An open-ended cylinder of radius r and thickness t is subjected to internal pressure p. The Young's modulus for the material is E and Poisson's ratio is μ. The longitudinal strain is

A. zero

B.

C.

D. none of these.

 Answer Option A

23. The force in BD of the truss shown in below figure is :

A. 500 kg compressive

B. 500 kg tensile

C. 1500 kg tensile

D. 1500 kg compressive

E. zero.

 Answer Option A

24. The bending moment at E for the structure shown in below figure, is

A. zero

B. 10 Tm

C. 20 Tm

D. 40 Tm.

 Answer Option A

25. A member which is subjected to reversible tensile or compressive stress may fail at a stress lower than the ultimate stress of the material. This property of metal, is called

A. plasticity of the metal

B. elasticity of the metal

C. fatigue of the metal

D. workability of the metal.

 Answer Option C

26. For a simply supported beam carrying uniformly distributed load W on it entire length L, the maximum bending moment is

A.

B.

C.

D.

E.

 Answer Option B

27. Euler's formula states that the buckling load P for a column of length l, both ends hinged and whose least moment of inertia and modulus of elasticity of the material of the column are I and E respectively, is given by the relation

A.

B.

C.

D.

E. P = πEl2.

 Answer Option A

28. The stiffness factor for a prismatic beam of length L and moment of inertia I, is

A.

B.

C.

D.

E.

 Answer Option A

29. The stress in the wall of a cylinder in a direction normal to its longitudinal axis, due to a force acting along the circumference, is known as

A. yield stress

B. longitudinal stress

C. hoop stress

D. circumferential stress

E. ultimate stress.

 Answer Option C

30. In a simply supported beam (l + 2a) with equal overhangs (a) and carrying a uniformly distributed load over its entire length, B.M. at the middle point of the beam will be zero if

A. l = 2a

B. l = 4a

C. l < 2a

D. l > a

E. l > 3a.

 Answer Option A

31. At either end of a plane frame, maximum number of possible bending moments, are

A. one

B. two

C. three

D. four

E. zero.

 Answer Option E

32. The principal stresses at a point are 100, 100 and-200 kgf/cm2, the octo hedral shear stress at the point is :

A. 100 2 kg/cm2

B. 200 2 kg/cm2

C. 300 2 kg/cm2

D. 400 2 kg/cm2

E. 500 2 kg/cm2.

 Answer Option A

33. During a tensile test on a ductile material

A. nominal stress at fracture is higher than the ultimate stress

B. true stress at fracture is higher than the ultimate stress

C. true stress at fracture is the same as the ultimate stress

D. none of these.

 Answer Option B

34. Rankine-Golden formula accounts for direct as well as buckling stress and is applicable to

A. very long columns

B. long columns

C. short columns

D. intermediate columns

E. all the above.

 Answer Option D

35. Pick up the correct statement from the following :

A. The point through which the resultant of the shear stresses, passes is known as shear centre

B. In the standard rolled channels, the shear centre is on the horizontal line passing through and away from the C.G. beyond web

C. In equal angles, the shear centre is on the horizontal plane and away from the C.G., outside of the leg projection

D. In T-sections, the shear centre is at the C.G. of the section

E. All the above.

 Answer Option E

36. In a three hinged arch, the bending moment will be zero

A. at right hinge only

B. at left hinge only

C. at both right and left hinges

D. at all the three hinges.

 Answer Option D

37. The ratio of the tensile stress developed in the wall of a boiler in the circumferential direction to the tensile stress in the axial direction, is

A. 4

B. 3

C. 2

D. 1

 Answer Option C

38. The force in the member DE of the truss shown in below figure will be

A. zero

B. 2 W tensile

C. 2 W compressive

D. 4 W compressive

E. 4 W tensile.

 Answer Option C

39. In a shaft shear stress intensity at a point is not

A. directly proportional to the distance from the axis

B. inversely proportional to the distance from the axis

C. inversely proportional to the polar moment of inertia

D. directly proportional to the applied torque.

 Answer Option B

40. Along the neutral axis of a simply supported beam

A. fibres do not undergo strain

B. fibres undergo minimum strain

C. fibres undergo maximum strain

D. none of these.

 Answer Option A

41. A joint of a frame is subjected to three tensile force P, Q and R equally inclined to each other. If P is 10 tonnes, the other forces will be

A. Q = 10 tonnes and R = zero

B. R + 10 tonnes and Q = zero

C. Q + R = 10 tonnes

D. Q - R = zero

E. Q and R each is equal to 10 tonnes.

 Answer Option E

42. If a member is subjected to a tensile force P, having its normal cross-section A, the resulting shear stress in an oblique plane inclined at an angle θ to its transverse plane, is

A.

B.

C.

D.

E.

 Answer Option B

43. A simply supported beam carries two equal concentrated loads W at distances L/3 from either support. The maximum bending moment

A.

B.

C.

D.

E.

 Answer Option A

44. If a solid shaft is subjected to a torque T at its end such that maximum shear stress does not exceed fz the diameter of the shaft will be

A.

B.

C.

D. none of these.

 Answer Option C

45. Pick up the correct statement from the following :

A. The distance of the eccentric axial load from the C.G. beyond which tension develops, is known as kern distance

B. In visco-elastic material, stress-strain relation is dependent on time

C. An instropic material has different properties is different directions

D. An orthotropic material has different properties in three mutually perpendicular directions

E. All the above.

 Answer Option E

46. In a simply supported beam L with a triangular load W varying from zero at one end to the maximum value at the other end, the maximum bending moment is

A.

B.

C.

D.

E.

 Answer Option D

47. Maximum deflection of a cantilever due to pure bending moment M at its free end, is

A.

B.

C.

D.

E.

 Answer Option D

48. Along the principal plan subjected to maximum principal stress

A. maximum shear stress acts

B. minimum shear stress acts

C. no shear stress acts

D. none of these.

 Answer Option C

49. A diagram which shows the variations of the axial load for all sections of the span of a beam, is called

A. bending moment diagram

B. shear force diagram

C. thrust diagram

D. stress diagram

E. none of these.

 Answer Option C

50. A member which does not regain its original shape after removed of load producing deformation is said

A. plastic

B. elastic

C. rigid

D. none of these.

 Answer Option A