Civil Engineering - Soil Mechanics and Foundation Engineering MCQs Part 1

1. In a liquid limit test, the moisture content at 10 blows was 70% and that at 100 blows was 20%. The liquid limit of the soil, is

A.
35%

B.
50%

C.
65%

D.
none of these.

 Answer Option C

2. The active earth pressure of a soil is proportional to (where φ is the angle of friction of the soil)

A.
tan (45° - φ)

B.
tan2 (45° + φ/2)

C.
tan2 (45° - φ/2)

D.
tan (45° + φ)

 Answer Option C

3. The minimum water content at which the soil just begins to crumble when rolled into threads 3 mm in diameter, is known

A.
liquid limit

B.
plastic limit

C.
shrinkage limit

D.
permeability limit.

 Answer Option B

4. Pick up the correct statement from the following:

A.
The rise of the ground surface due to frost action is called frost heave.

B.
The freezing of water is accompained by a volume increase of 9%.

C.
Below freezing point, higher soil suction develops.

D.
The magnitude of frost heave decreases as the degree of saturation of soil decreases

E.
All the above.

 Answer Option E

5. Which one of the following statements is true ?

A.
Clays are more porous than sands

B.
Pressure of organic matter in a soil decreases the bearing capacity of the soil

C.
Aluminous cement is used for foundations in soils with chemical deposits

D.
All the above.

 Answer Option D

6. The lateral earth pressure on a retaining wall

A. is equal to mass of the soil retained

B. proportional to the depth of the soil

C. proportional to the square of the depth of the soil

D. proportional to the internal friction of the soil

E. none of these.

 Answer Option D

7. The internal molecular attraction of a soil, the cohesion

A. decreases as the moisture content increases

B. increases as the moisture content decreases

C. is more in well compacted clays

D. depends upon the external applied load.

 Answer Option C

8. The quantity of seepage of water through soils is proportional to

A. coefficient of permeability of soil

B. total head loss through the soil

C. neither (a) nor (b)

D. both (a) and (b).

 Answer Option D

9. When drainage is permitted under initially applied normal stress only and full primarily consolidation is allowed to take place, the test is known as

A. quick test

B. drained test

C. consolidated undrained test

D. none of these.

 Answer Option C

10. The minimum water content at which the soil retains its liquid state and also possesses a small shearing strength against flowing, is known

A. liquid limit

B. plastic limit

C. shrinkage limit

D. permeability limit.

 Answer Option A

11. Minimum size of the particles of silt soil, is

A. 0.002 mm

B. 0.04 mm

C. 0.06 mm.

D. 0.08 mm

E. 1 mm

 Answer Option A

12. The maximum value of effective stress in the past divided by the present value, is defined as over consolidation ratio (OCR). The O.C.R. of an over consolidated clay is

A. less than 1

B. 1

C. more than 1

D. None of these.

 Answer Option C

13. If Nf, Nd and H are total number flow channels, total number of potential drops and total hydraulic head differences respectively, the discharge q through the complete flow is given by (where K is a constant)

A.

B.

C.

D.

 Answer Option C

14. A flow line makes angles θ1 and θ2 with the normal to the interface of the soils having permeabilities k1, k2 before and after deflection. According to the law of deflection of the flow lines at the interface of the dissimilar soils

A.

B.

C.

D.

 Answer Option C

15. Under-reamed piles are generally

A. driven piles

B. bored piles

C. precast piles

D. all the above.

 Answer Option B

16. Pick up the clay soil group which does not swell when wet from the following :

A. Kaolinite group

B. Illite group

C. Vermiculite group

D. Montrorillonite group.

 Answer Option B

17. Factor of safety against sliding of a slope, is the ratio of

A. actual cohesion to that required to maintain stability of slope

B. shear strength to shear stress along the surface

C. neither (a) nor (b)

D. both (a) and (b).

 Answer Option D

18. The ratio of the volume of voids to the volume of soil solids in a given soil mass, is known

A. porosity

B. specific gravity

C. void ratio

D. water content.

 Answer Option C

19. A compacted soil sample using 10% moisture content has a weight of 200 g and mass unit weight of 2.0 g/cm3. If the specific gravity of soil particles and water are 2.7 and 1.0, the degree of saturation of the soil is

A. 11.1%

B. 55.6%

C. 69.6%

D. none of these.

 Answer Option B

20. A partially saturated sample of soil has a unit weight of 2.0 g/cm3 and specific gravity of soil particles is 2.6. If the moisture content in the soil is 20%, the degree of saturation is

A. 20%

B. 77%

C. 92%

D. none of these.

 Answer Option C

21. Minimum depth of a footing carrying a heavy load, is calculated by the formula

A.

B.

C.

D.

 Answer Option B

22. According to Coulomb's wedge theory, the active earth pressure slides the wedge

A. down and outwards on a slip surface

B. up and inwards on a slip surface

C. horizontal upward and parallel to base

D. horizontal inward and parallel to base.

 Answer Option A

23. The coefficient of curvature is defined

A.

B.

C.

D.

 Answer Option C

24. The effective size of particles of soil is denoted by

A. D10

B. D20

C. D30

D. D60

 Answer Option A

25. Degree of saturation of a natural soil deposit having water content 15%, specific gravity 2.50 and void ratio 0.5, is

A. 50%

B. 60%

C. 75%

D. 80%

 Answer Option C

26. The coefficient of compressibility of soil, is the ratio of

A. stress to strain

B. strain to stress

C. stress to settlement

D. rate of loading to that of settlement.

 Answer Option B

27. If the failure of a finite slope occurs through the toe, it is known as

A. slope failure

B. face failure

C. base failure

D. toe failure.

 Answer Option D

28. Rankine's theory of active earth pressure assumes

A. soil mass is homogeneous, dry and cohesionless

B. ground surface is a plane which may be horizontal or inclined

C. back of the wall is vertical and smooth

D. wall yields about the base

E. all the above.

 Answer Option E

29. The water content of soil is defined as the ratio of

A. volume of water to volume of given soil

B. volume of water to volume of voids in soil

C. weight of water to weight of air in voids

D. weight of water to weight of solids of given mass of soil.

 Answer Option D

30. Accurate determination of water content, is made by

A. calcium carbide method

B. sand bath method

C. alcohol method

D. oven-drying method.

 Answer Option D

31. Stoke's law sates that the velocity at which a grain settles out of suspension, the other factors remaining constant, is dependent upon

A. shape of grain

B. weight of grain

C. size of grain

D. shape and size of grain

E. shape, size and weight of grain.

 Answer Option E

32. Pick up the correct statement from the following:

A. When water table is above the base of a footing, the dry weight m should be used for soil below water table

B. When water table is located somewhat below the base of a footing, the elastic wedge is partly of moist soil and partly of submerged soil, and a suitable reduction factor is used

C. When water table is just at the base of the footing, no reduction factor is used

D. None of these.

 Answer Option B

33. Pick up the correct statement from the following :

A. In soils, the flow index indicates variation in shear strength with water content

B. Liquid limit minus plastic limit, is known as plasticity index of the soil

C. Plastic limit minus shrinkage limit, is known as shrinkage index of the soil

D. The ratio of the plasticity index to the flow limit, is known as toughness index of the soil

E. All the above.

 Answer Option E

34. If S, L and R are the arc length, long chord and radius of the sliding circle then the perpendicular distance of the line of the resultant cohesive force, is given by

A.

B.

C.

D. none of these.

 Answer Option A

35. The liquid limit and plastic limit exist in

A. sandy soils

B. silty soils

C. gravel soils

D. clay soils.

 Answer Option D

36. Back fill with a sloping surface exerts a total active pressure Pa on the wall of height H and acts at

A. H/4 above the base parallel to base

B. H/2 above the base parallel to base

C. H/3 above the base parallel to base

D. H/5 above the base parallel to base.

 Answer Option C

37. The ratio of the weight of given volume of soil solids to the weight of an equal volume of distilled water at the given temperature, is known

A. porosity

B. specific gravity

C. void ratio

D. water content.

 Answer Option B

38. The ultimate Settlement of a soil is directly proportional to:

A. depth of the compressible soil strata

B. compressive index

C. void ratio

D. both (a) and (b)

E. none of these.

 Answer Option D

39. The seepage force in a soil, is

A. perpendicular to the equipotential lines

B. proportional to the exit graident

C. proportional to the head loss

D. all the above.

 Answer Option D

40. A soil has bulk density 2.30 g/cm3 and water content 15 per cent, the dry density of the sample, is

A. 1.0 g/cm2

B. 1.5 g/cm3

C. 2.0 g/cm3

D. 2.5 g/cm3

 Answer Option C

41. Pick up the correct statement from the following:

A. Sandy clayloam contains highest percentage of sand

B. Silty clayloam contains highest percentage of silt

C. Stiff boulder clay offers maximum shear strength

D. Soft chalk carries least safe load

E. All the above.

 Answer Option B

42. The clay soil mainly consists of

A. Kaolinites .

B. Montomorillonite

C. Illites

D. Vermiculite

E. All the above.

 Answer Option E

43. The liquidity index is defined as a ratio expressed as percentage of

A. plastic limit minus the natural water content, to its plasticity index

B. natural water content minus its plastic limit to its plasticity index

C. natural water content plus its plastic limit to its plasticity index

D. liquid limit minus the natural water content to the plasticity index.

 Answer Option B

44. The fluid generally used for grouting is

A. cement and water mix

B. clay suspension

C. sodium silicate

D. bitumen emulsion

E. all the above.

 Answer Option E

45. A coarse-grained soil has a voids ratio 0.75, and specific gravity as 2.75. The critical gradient at which quick sand condition occurs, is

A. 0.25

B. 0.50

C. 0.75

D. 1.00

 Answer Option D

46. The relationship between void ratio (e) and porosity ratio (n) is :

A. n =

B. e =

C. n =

D. e = n/(1 - n)

 Answer Option D

47. Failure of the stability of slopes, generally occurs along

A. slip plane

B. a horizontal surface

C. a curved surface

D. all the surfaces.

 Answer Option C

48. Pick up the correct statement from the following:

A. Failure plane carries maximum shear stress

B. Failure plane does not carry maximum shear stress

C. Failure plane carries shear stress equal to maximum shear stress

D. None of these.

 Answer Option B

49. Geologic cycle for the formation of soil, is

A. Upheavel → transportation → deposition → weathering

B. Weathering → upheaval → transportation → deposition

C. Transportation → upheaval → weathering → deposition

D. Weathering → transportation → deposition → upheaval

E. None of these.

 Answer Option D

50. The weight of a pycnometer containing 400 g sand and water full to the top is 2150 g. The weight of pycnometer full of clean water is 1950 g. If specific gravity of the soil is 2.5, the water content is

A. 5%

B. 10%

C. 15%

D. 20%

 Answer Option D