MCQ Soil mechanics

MCQ Soil mechanics

Q1. The unit of permeability coefficient in SI system is:

m/s N/m² m²/s kg/m³

Q2. Which soil type has the highest permeability?

Clay Silt Sand Peat

Q3. The consistency limits of a soil are determined using:

Proctor test Atterberg test Plate load test CBR test

Q4. The unconfined compressive strength test is applicable for:

Cohesionless soils Saturated clays Dry sand Gravel

Q5. Degree of saturation is expressed as:

Percentage of water content Percentage of voids filled with water Dry density Relative density

Q6. The dry density is maximum when:

Soil is saturated Optimum moisture content is reached Soil is fully dry Relative density is zero

Q7. The water content at which soil changes from liquid to plastic state is:

Plastic limit Liquid limit Shrinkage limit Saturation limit

Q8. Relative density is applicable to:

Cohesive soils Cohesionless soils Peaty soils Expansive soils

Q9. The term 'bulking' is associated with:

Clay Sand Silt Gravel

Q10. The compressibility of clay is:

Low Very low High Zero

Q11. Which method is commonly used for field compaction control?

Proctor test Sand replacement method CBR test Plate load test

Q12. CBR test is performed to assess:

Shear strength of soil Permeability of soil Bearing capacity of subgrade Moisture content

Q13. Coefficient of permeability depends mainly on:

Soil particle size Soil color Plasticity index None of these

Q14. Swelling pressure is significant in:

Sandy soil Gravelly soil Expansive clay Silty soil

Q15. Which equipment is preferred for compacting cohesive soils?

Smooth wheel roller Sheep foot roller Pneumatic roller Vibratory roller

Q16. In a soil sample, the void ratio is:

Volume of voids / Volume of solids Volume of water / Total volume Volume of solids / Total volume None of these

Q17. Which soil has the highest dry density for the same compactive effort?

Sand Clay Peat Silt

Q18. The plasticity index is defined as:

LL - PL SL - LL LL - SL PL + LL

Q19. Which soil classification system is used by Indian railways?

IS classification USCS AASHTO HRB classification

Q20. Clay soil particles are predominantly shaped:

Spherical Plate-like Needle-shaped Irregular

Q21. The ratio of weight of water to weight of solids in a soil mass is:

Degree of saturation Water content Specific gravity Porosity

Q22. The ratio of volume of voids to total volume is called:

Porosity Void ratio Degree of saturation Water content

Q23. Which soil has negligible plasticity?

Clay Silt Sand Peat

Q24. Liquid limit can be determined by:

Proctor apparatus CBR machine Casagrande device Plate load test

Q25. Effective stress is:

Total stress + pore water pressure Pore water pressure only Total stress - pore water pressure Sum of pore water and atmospheric pressure

Q26. Consolidation of clay occurs due to:

Rapid drainage Gradual expulsion of pore water Increase in air voids Vibration

Q27. The primary cause of settlement in saturated clays is:

Increase in temperature Loss of air voids Dissolution of solids Expulsion of pore water

Q28. The total unit weight of a fully saturated soil is called:

Submerged unit weight Bulk unit weight Saturated unit weight Dry unit weight

Q29. Which factor affects the shear strength of soil?

Cohesion Angle of internal friction Pore water pressure All of these

Q30. The critical hydraulic gradient in soils is given by:

G-1 / (1+e) (G-1)(1+e) (G+e)/(1+e) (G-1)e

Q31. Capillarity rise is more in:

Coarse sand Fine sand Gravel Silt and clay

Q32. Soil permeability decreases with:

Increase in grain size Increase in void ratio Decrease in temperature Increase in water content

Q33. The active earth pressure is minimum when:

Wall moves away from backfill Wall is at rest Wall moves towards soil Wall is restrained

Q34. The shear strength of cohesionless soils is due to:

Cohesion only Angle of internal friction Pore pressure None of these

Q35. Ultimate bearing capacity is:

Net safe load per unit area Load causing foundation failure Allowable load with factor of safety Load carrying capacity at zero settlement

Q36. Which one of the following has highest permeability?

Gravel Fine sand Clay Silt

Q37. Which test is used to determine unconfined compressive strength?

UCS test CBR test Direct shear test Plate load test

Q38. The property of soil to resist shear stress is called:

Compressibility Shear strength Cohesion Plasticity

Q39. The air content of a soil sample is:

Volume of air/volume of voids Volume of water/volume of solids Weight of air/weight of water Volume of water/volume of voids

Q40. Coefficient of curvature (Cc) is given by:

(D60 x D30)/(D10²) (D30)²/(D60 x D10) D10/(D60 x D30) (D10 x D60)/(D30²)

Q41. The compaction of granular soils is best achieved by:

Kneading action Static load Vibration Impact

Q42. The consistency index is given by:

(LL - w)/(LL - PL) (PL - w)/(LL - PL) (w - PL)/(LL - PL) (LL - PL)/(w - PL)

Q43. In a grain size distribution curve, a well-graded soil has:

Steep curve Flat curve Uniform curve Irregular curve

Q44. In Terzaghi’s theory, the time factor (T) is given by:

Cv × t / H² Cv / (t × H²) t / (Cv × H²) Cv × H² / t

Q45. Darcy’s law is valid for:

Turbulent flow Laminar flow Transitional flow Supercritical flow

Q46. Critical hydraulic gradient leads to:

Piping failure Swelling Increase in dry density Increase in permeability

Q47. The principal stress in vertical direction in saturated soil is:

Total stress Effective stress Pore water pressure None of these

Q48. A soil is said to be over-consolidated if:

Pc = Po Pc > Po Pc < Po Pc = 0

Q49. The clay mineral having highest swelling potential is:

Kaolinite Illite Montmorillonite Chlorite

Q50. The ratio of saturated unit weight to dry unit weight is always:

Less than one Equal to one Greater than one Zero

Q51. The laboratory test generally used for determining permeability of clayey soil is:

Constant head test Falling head test Plate load test Direct shear test

Q52. Coefficient of consolidation is affected by:

Compressibility Permeability Unit weight of water All of these

Q53. The value of compression index (Cc) for a normally consolidated clay can be estimated from:

Plasticity index Grain size analysis Shrinkage limit Void ratio

Q54. The area under the e-log p curve in a consolidation test represents:

Pore pressure Total settlement Volume change Effective stress

Q55. The maximum dry density of a soil is achieved at:

Zero water content Saturation point Optimum moisture content Air-dry state

Q56. The ratio of volume of air voids to total volume of voids is known as:

Degree of saturation Air content Porosity Water content

Q57. The unconfined compressive strength test is conducted on:

Cohesive soils Granular soils Organic soils Coarse gravels

Q58. Which soil shows dilatancy behavior when sheared?

Dense sand Loose sand Soft clay Organic soil

Q59. Which method is commonly used for determining shear strength of soil in lab?

Permeability test Direct shear test Triaxial test Both B and C

Q60. Coefficient of volume compressibility (mv) is:

Unit volume change per unit pressure increase Volume change per unit volume Pressure increase per volume change None of these

Q61. The shear strength parameters of a soil are determined from:

Direct shear test CBR test Proctor compaction test Consolidation test

Q62. A soil with Cu > 4 and 1 < Cc < 3 is considered:

Uniformly graded Well-graded Poorly graded Gap graded

Q63. Bulking of sand occurs due to:

Surface tension of water Capillarity Adhesion between particles None of these

Q64. The major factor influencing permeability of soil is:

Void ratio Soil type Temperature Water content

Q65. If the degree of saturation is 100%, then air content is:

1.0 0.5 0.0 Depends on void ratio

Q66. Quick condition in soil occurs when:

Effective stress becomes zero Void ratio increases Permeability reduces Degree of saturation increases

Q67. Critical hydraulic gradient depends upon:

Specific gravity and void ratio Porosity only Unit weight of soil Grain size

Q68. During consolidation, rate of settlement is directly proportional to:

Permeability Compressibility Void ratio Cohesion

Q69. The plastic limit of a soil is:

Lower limit of liquid state Upper limit of liquid state Lower limit of plastic state Upper limit of plastic state

Q70. The Atterberg limits are applicable to:

Sands Gravels Cohesive soils Organic soils

Q71. The main reason for soil compaction in the field is to:

Reduce permeability Increase strength Reduce settlement All of the above

Q72. The triaxial test is preferred over the direct shear test because:

It allows drainage control It simulates field stress conditions better Both A and B It is simpler

Q73. The standard proctor test uses a hammer of:

2.5 kg 4.5 kg 5.0 kg 10.0 kg

Q74. The primary consolidation of soil occurs due to:

Expulsion of pore water Compression of soil grains Creep of soil particles Both B and C

Q75. Which one of the following clays exhibits highest plasticity?

Kaolinite Illite Montmorillonite None of these

Q76. Coarse-grained soils are classified by:

Liquid limit and plastic limit Particle size distribution Field dry density Organic content

Q77. Degree of saturation is zero when:

Soil is fully dry Soil is fully saturated Water table rises Soil is submerged

Q78. Which of the following increases permeability of soil?

Increase in void ratio Decrease in grain size Increase in viscosity Decrease in temperature

Q79. Shear strength of a soil is mainly contributed by:

Cohesion only Friction only Both cohesion and friction None of these

Q80. Plasticity index is defined as:

LL - PL PL - LL LL + PL None of these

Q81. The consistency of a fine-grained soil is expressed by:

Atterberg limits Sieve analysis Proctor test CBR test

Q82. In a flow net, the flow lines and equipotential lines:

Are parallel Are perpendicular Intersect at 45° Are concentric

Q83. Which one of the following affects the compaction characteristics of soil?

Water content Type of compaction effort Type of soil All of the above

Q84. Specific gravity of soil solids is typically determined using:

Pycnometer Hydrometer Core cutter Casagrande device

Q85. The shear strength of saturated clay under undrained conditions is equal to:

Friction angle Cohesion only Both cohesion and friction None of these

Q86. A high liquid limit indicates:

High compressibility Low compressibility High permeability Low plasticity

Q87. Standard penetration test (SPT) is used to determine:

Compaction Shear strength Relative density Atterberg limits

Q88. Which factor influences the effective stress in soil?

Pore water pressure Total stress Both A and B None of these

Q89. Compaction energy is directly proportional to:

Number of blows Hammer weight Drop height All of these

Q90. Piping in soil occurs when:

Seepage pressure exceeds effective stress Water content exceeds liquid limit Degree of saturation becomes 100% Void ratio exceeds 1.0

Q91. The unit of coefficient of permeability is:

m/s m²/s m m³/s

Q92. Which test is suitable for determining field density of cohesive soils?

Sand replacement method Core cutter method Nuclear density test Hydrometer analysis

Q93. The term ‘cohesionless soil’ refers to:

Clays Silts Sands and gravels Organic soils

Q94. Which IS code provides guidelines for soil classification?

IS 2720 (Part 3) IS 1498 IS 456 IS 6403

Q95. The maximum dry density obtained by modified proctor test is:

Lower than standard proctor Same as standard proctor Higher than standard proctor Depends on soil type

Q96. Which soil property increases permeability?

Higher specific surface area Higher porosity Higher plasticity index Higher unit weight

Q97. Consistency index (Ic) is defined as:

(LL - PL) / (LL - SL) (LL - W) / (LL - PL) (W - PL) / (LL - PL) (W - SL) / (PL - SL)

Q98. During compaction, optimum moisture content (OMC) is:

Maximum possible water content Water content at maximum dry density Zero water content Water content at liquid limit

Q99. The bearing capacity of soil mainly depends on:

Shear strength Void ratio Liquid limit Permeability

Q100. Which soil has the maximum void ratio?

Gravel Sand Silt Clay