### Civil Engineering - Theory of Structures MCQs Part 4

1. In case of principal axes of a section

A.
sum of moment of inertia is zero
B.
difference of moment inertia is zero
C.
product of moment of inertia is zero
D.
none of these.

2. The forces acting normally on the cross section of a bar shown in the given figure introduce

A.
compressive stress
B.
tensile stress
C.
shear stress
D.
none of these.

3. The maximum deflection due to a load W at the free end of a cantilever of length L and having flexural rigidity EI, is

A.
B.
C.
D.

4. If the normal stresses due to longitudinal and transverse loads on a bar are σ1 and σ2 respectively, the tangential component of the stress on an inclined plane through θ°, the longitudinal load is

A.
σ1 sin θ + σ2 cos θ
B.
σ1 sin θ2 + σ2 cos2 θ
C.
D.

5. The ratio of the section modulus of a square section of side B and that of a circular section of diameter D, is

A.
B.
C.
D.

6. The force in BC of the truss shown in the given figure, is

A. 3.0t compression
B. 3.0t tension
C. t tension
D. t compression
E. None of these.

7. The equivalent length of a column of length L, having one end fixed and other end hinged, is

A. 2L
B. L
C.
D.

8. At any point of a beam, the section modulus may be obtained by dividing the moment of inertia of the section by

A. depth of the section
B. depth of the neutral axis
C. maximum tensile stress at the section
D. maximum compressive stress at the section
E. none of these.

9. For calculating the permissible stress is the emprical formula, known as

A. Straight line formula
B. Parabolic formula
C. Perry's formula
D. Rankine's formula.

10. The maximum height of a masonry dam of a triangular section whose base width is b and specific gravity s, is

A. bs
B. b.s
C. bs
D. s b
E.

11. The load on a spring per unit deflection, is called

A. stiffness
B. proof resilience
C. proof stress

12. In a shaft, the shear stress is not directly proportional to

B. angle of twist
C. length of the shaft
D. modulus of rigidity.

13. Ab and Ac are the cross sections of bronze and copper bars of equal length, σb, σc are their respective stresses due to load P. If Pb and Pc are the loads shared by them, (where Eb and Ec are their modulii).

A.
B. P = Pb + Pc
C. P = Ab σb + Ac σb
D. all the above

14. A compound truss may be formed by connecting two simple rigid frames, by

A. two bars
B. three bars
C. three parallel bars
D. three bars intersecting at a point.

15. The locus of the end point of the resultant of the normal and tangential components of the stress on an inclined plane, is

A. circle
B. parabola
C. ellipse
D. straight line.

16. The degree of indeterminacy of the frame in the given figure, is

A. zero
B. 1
C. 2
D. 3

17. The equivalent length of a column of length L having one end fixed and the other end free, is

A. 2L
B. L
C.
D.

18. To determine the force in BD of the truss shown in the given figure a section is passed through BD, CD and CE, and the moments are taken about

A. A joint
B. B joint
C. C joint
D. D joint.

19. The ratio of the length and depth of a simply supported rectangular beam which experiences maximum bending stress equal to tensile stress, due to same load at its mid span, is

A.
B.
C.
D.

20. The radius of gyration of a rectangular section (depth D, width B) from a centroidal axis parallel to the width is

A.
B.
C.
D.

21. For a strongest rectangular beam cut from a circular log, the ratio of the width and depth, is

A. 0.303
B. 0.404
C. 0.505
D. 0.606
E. 0.707

22. The moment of inertia of a circular section about any diameter D, is

A.
B.
C.
D.

23. The ratio of maximum and average shear stresses on a rectangular section, is

A. 1
B. 1.25
C. 1.5
D. 2.0
E. 2.5

24. The locus of the moment of inertia about inclined axes to the principal axis, is

A. straight line
B. parabola
C. circle
D. ellipse.

25. A lift of weight W is lifted by a rope with an acceleration f. If the area of cross-section of the rope is A, the stress in the rope is

A.
B.
C.
D.

26. A close coil helical spring of mean diameter D consists of n coils of diameter d. If it carries an axial load W, the energy stored in the spring, is

A.
B.
C.
D.

27. A simply supported beam A carries a point load at its midspan. An other identical beam B carries the same load but uniformly distributed over the entire span. The ratio of the maximum deflections of the beams A and B, will be

A.
B.
C.
D.

28. The maximum deflection of a simply supported beam of span L, carrying an isolated load at the centre of the span ; flexural rigidity being EI, is

A.
B.
C.
D.

29. The strain energy due to volumetric strain

A. is directly proportional to the volume
B. is directly proportional to the square of exerted pressure
C. is inversely proportional to Bulk modulus
D. all the above.

30. If the strain energy stored per unit volume in a hollow shaft subjected to a pure torque when t attains maximum shear stress fs the ratio of inner diameter to outer diameter, is

A.
B.
C.
D.

31. m1 and m2 are the members of two individual simple trusses of a compound truss. The compound truss will be rigid and determinate if

A. m = m1 + m2
B. m = m1 + m2 + 1
C. m = m1 + m2 + 2
D. m = m1 + m2 + 3

32. In case of a simply supported I-section beam of span L and loaded with a central load W, the length of elasto-plastic zone of the plastic hinge, is

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

6. The force in BC of the truss shown in the given figure, is

A. 3.0t compression
B. 3.0t tension
C. t tension
D. t compression
E. None of these.

7. The equivalent length of a column of length L, having one end fixed and other end hinged, is

A. 2L
B. L
C.
D.

8. At any point of a beam, the section modulus may be obtained by dividing the moment of inertia of the section by

A. depth of the section
B. depth of the neutral axis
C. maximum tensile stress at the section
D. maximum compressive stress at the section
E. none of these.

9. For calculating the permissible stress is the emprical formula, known as

A. Straight line formula
B. Parabolic formula
C. Perry's formula
D. Rankine's formula.

10. The maximum height of a masonry dam of a triangular section whose base width is b and specific gravity s, is

A. bs
B. b.s
C. bs
D. s b
E.