51. Physical properties of a permeant which influence permeability are
a) viscosity only
b) unit weight only
c) both viscosity and unit weight
d) none of the above
Ans:c
52. Select the correct statement.
a) The greater the viscosity, the greater is permeability.
b) The greater the unit weight, the greater is permeability.
c) The greater the unit weight, the smaller is permeability.
d) Unit weight does not affect per-meability.
Ans:b
53. Effective stress on soil
a) increases voids ratio and decreases permeability
b) increases both voids ratio and per-meability
c) decreases both voids ratio and per-meability
d) decreases voids ratio and increases permeability
Ans:c
54. If the permeability of a soil is 0.8 mm/sec, the type of soil is
a) gravel
b) sand
c) silt
d) clay
Ans:b
55. Which of the following methods is more suitable for the determination of permeability of clayey soil ?
a) constant head method
b) falling head method
c) horizontal permeability test
d) none of the above
Ans:b
56. Which of the following methods is best suited for determination of permeability of coarsegrained soils ?
a) constant head method
b) falling head method
c) both the above
d) none of the above
Ans:a
57. Due to a rise in temperature, the viscosity and the unit weight of the percolating fluid are reduced to 60% and 90% respectively. If other things remain constant, the coefficient of permeability
a) increases by 25%
b) increases by 50%
c) increases by 33.3%
d) decreases by 33.3%
Ans:b
58. Coefficient of permeability of soil
a) does not depend upon temperature
b) increases with the increase in tempe-rature v
c) increases with the decrease in tempe-rature
d) none of the above
Ans:b
59. The average coefficient of permeability of natural deposits
a) parallel to stratification is always greater than that perpendicular to stratification
b) parallel to stratification is always less than that perpendicular to stratifi-cation
c) is always same in both directions
d) parallel to stratification may or may not be greater than that perpendicular to stratification
Ans:a
60. The total discharge from two wells situated near to each other is
a) sum of the discharges from individual wells
b) less than the sum of the discharges from individual wells
c) greater than the sum of the discharges from individual wells
d) equal to larger of the two discharges from individual wells
Ans:b
61. The flownet for an earthen dam with 30 m water depth consists of 25 potential drops and 5 flow channels. The coefficient of permeability of dam material is 0.03 mm/sec. The discharge per metre length of dam is
a) 0.00018 nrVsec
b) 0.0045 m3/sec
c) 0.18m3/sec
d) 0.1125m3/sec
Ans:a
62. The most suitable method for drainage of fine grained cohesive soils is
a) well ppint system
b) vacuum method
c) deep well system
d) electro-osmosis method
Ans:d
63. Total number of stress components at a point within a soil mass loaded at its boundary is
a) 3
b) 6
c) 9
d) 16
Ans:c
64. The slope of isochrone at any point at a given time indicates the rate of change of
a) effective stress with time
b) effective stress with depth
c) pore water pressure with depth
d) pore water pressure with time
Ans:c
65. Within the consolidation process of a saturated clay
a) a gradual increase in neutral pressure and a gradual decrease in effective pressure takes place and sum of the two is constant
b) a gradual decrease in neutral pressure and a gradual increase in effective pressure takes place and sum of the two is constant
c) both neutral pressure and effective pressure decrease
d) both neutral pressure and effective pressure increase
Ans:b
66. The value of compression index for a remoulded sample whose liquid limit is 50% is
a) 0.028
b) 0.28
c) 036
d) 0.036
Ans:b
67. Which one of the following clays behaves like a dense sand ?
a) over-consolidated ciay with a high over-consolidation ratio
b) over-consolidated clay with a low over-consolidation ratio
c) normally consolidated clay
d) under-consolidated clay
Ans:a
68. Coefficient of consolidation of a soil is affected by
a) compressibility
b) permeability
c) both compressibility and permeability
d) none of the above
Ans:c
69. Degree of consolidation is
a) directly proportional to time and inversely proportional to drainage path
b) directly proportional to time and inversely proportional to square of drainage path
c) directly proportional to drainage path and inversely proportional to time
d) directly proportional to square of drainage path and inversely proportional to time
Ans:b
70. Time factor for a clay layer is
a) a dimensional parameter
b) directly proportional to permeability of soil
c) inversely proportional to drainage path
d) independent of thickness of clay layer
Ans:b
71. Clay layer A with single drainage and coefficient of consolidation Cv takes 6 months to achieve 50% consolidation. The time taken by clay layer B of the same thickness with double drainage and coefficient of consolidation Cv/2 to achieve the same degree of consolidation is
a) 3 months
b) 6 months
c) 12 months
d) 24 months
Ans:a
72. Coefficient of consolidation for clays normally
a) decreases with increase in liquid limit
b) increases with increase in liquid limit
c) first increases and then decreases with increase in liquid limit
d) remains constant at all liquid limits
Ans:a
73. Direct measurement of permeability of the specimen at any stage of loading can be made
a) only in fixed ring type consolido-meter
b) only in floating ring type consolido-meter
c) both (a) and (b)
d) none of the above
Ans:a
74. Compressibility of sandy soils is
a) almost equal to that of clayey soils
b) much greater than that of clayey soils
c) much less than that of clayey soils
d) none of the above
Ans:c
75. Select the correct statement.
a) coefficient of compressibility of an over-consolidated clay is less than that of a normally consolidated clay
b) coefficient of compressibility of an over-consolidated clay is greater than that of a normally consolidated clay
c) coefficient of compressibility is cons-tant for any clay
d) none of the above
Ans:a