26. Which of the following statements is correct?
a) Uniformity coefficient represents the shape of the particle size distribution curve.
b) For a well graded soil, both uniformity coefficient and coefficient of curvature are nearly unity.
c) A soil is said to be well graded if it has most of the particles of about the same size
d) none of the above
Ans:d
27. Uniformity coefficient of a soil is
a) always less than 1
b) always equal to 1
c) equal to or less than 1
d) equal to or gi eater than 1
Ans:d
28. According to Atterberg, the soil is said to be of medium plasticity if the plasticity index PI is
a) 0 < PI < 7
b) 7<PI< 17
c) 17<PI27
Ans:b
29. If the natural water content of soil mass lies between its liquid limit and plastic limit, the soil mass is said to be in
a) liquid state
b) plastic state
c) semi-solid state
d) solid state
Ans:b
30. When the plastic limit of a soil is greater than the liquid limit, then the plasticity index is reported as
a) negative
b) zero
c) non-plastic (NP)
d) 1
Ans:b
31. Toughness index is defined as the ratio of
a) plasticity index to consistency index
b) plasticity index to flow index
c) liquidity index to flow index
d) consistency index to liquidity index
Ans:b
32. If the plasticity index of a soil mass is zero, the soil is
a) sand
b) silt
c) clay
d) clayey silt
Ans:a
33. The admixture of coarser particles like sand or silt to clay causes
a) decrease in liquid limit and increase in plasticity index
b) decrease in liquid limit and no change in plasticity index
c) decrease in both liquid limit and plasticity index
d) increase in both liquid limit and plasticity index
Ans:c
34. Select the correct statement.
a) A uniform soil has more strength and stability than a non-uniform soil.
b) A uniform soil has less strength and stability than a non-uniform soil.
c) Uniformity coefficient does not affect strength and stability.
d) Uniformity coefficient of a poorly graded soil is more than that of a well graded soil.
Ans:b
35. The water content of soil, which represents the boundary between plastic state and liquid state, is known as
a) liquid limit
b) plastic limit
c) shrinkage limit
d) plasticity index
Ans:a
36. Which of the following soils has more plasticity index ?
a) sand
b) silt
c) clay
d) gravel
Ans:c
37. At liquid limit, all soils possess
a) same shear strength of small magnitude
b) same shear strength of large magnitude
c) different shear strengths of small magnitude
d) different shear strengths of large magnitude
Ans:a
38. If the material of the base of the Casagrande liquid limit device on which the cup containing soil paste drops is softer than the standard hard rubber, then
a) the liquid limit of soil always increases
b) the liquid limit of soil always decreases
c) the liquid limit of soil may increase
d) the liquid limit of soil may decrease
Ans:a
39. According to IS classification, the range of silt size particles is
a) 4.75 mm to 2.00 mm
b) 2.00 mm to 0.425 mm
c) 0.425 mm to 0.075 mm
d) 0.075 mm to 0.002 mm
Ans:d
40. Highway Research Board (HRB) classification of soils is based on
a) particle size composition
b) plasticity characteristics
c) both particle size composition and plasticity characteristics
d) none of the above
Ans:c
41. Inorganic soils with low compressibility are represented by
a) MH
b) SL
c) ML
d) CH
Ans:c
42. Sand particles are made of
a) rock minerals
b) kaolinite
c) illite
d) montmorillonite
Ans:a
43. The clay mineral with the largest swelling and shrinkage characteristics is
a) kaolinite
b) illite
c) montmorillonite
d) none of the above
Ans:c
44. Dispersed type of soil structure is an arrangement comprising particles having
a) face to face or parallel orientation
b) edge to edge orientation
c) edge to face orientation
d) all of the above
Ans:a
45. Effective stress is
a) the stress at particles contact
b) a physical parameter that can be measured
c) important because it is a function of engineering properties of soil
d) all of the above
Ans:c
46. Rise of water table above the ground surface causes
a) equal increase in pore water pressure and total stress
b) equal decrease in pore water pressure and total stress
c) increase in pore water pressure but decrease in total stress
d) decrease in pore water pressure but increase in total stress
Ans:a
47. The total and effective stresses at a depth of 5 m below the top level of water in a swimming pool are respectively
a) zero and zero
b) 0.5 kg/cm2 and zero
c) 0.5 kg/cm2 and 0.5 kg/cm2
d) 1.0 kg/cm2 and 0.5 kg/cm2
Ans:b
48. If the water table rises upto ground surface, then the
a) effective stress is reduced due to decrease in total stress only but pore water pressure does not change
b) effective stress is reduced due to increase in pore water pressure only but total stress does not change
c) total stress is reduced due to increase in pore water pressure only but effec-tive stress does not change
d) total stress is increased due to de-crease in pore water pressure but effective stress does not change
Ans:b
49. Quick sand is a
a) type of sand
b) flow condition occurring in cohesive soils
c) flow condition occurring in cohesionless soils
d) flow condition occurring in both cohesive and cohesionless soils
Ans:a
50. The hydraulic head that would produce a quick condition in a sand stratum of thickness 1.5 m, specific gravity 2.67 and voids ratio 0.67 is equal to
a) 1.0m
b) 1.5 m
c) 2.0 m
d) 3m
Ans:b