SSC JE–pattern practice set for Soil Mechanics:
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100 MCQs
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Topic-wise
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Moderate level
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Each question has a short explanation (so you learn while practicing)
SOIL MECHANICS – 100 MCQs (SSC JE Pattern)
🔹 TOPIC 1: BASIC SOIL PROPERTIES (Q1–Q15)
Q1. Void ratio is defined as
A) Vv/V
B) Vs/V
C) Vv/Vs
D) Va/Vw
Ans: C
Explanation: Void ratio = volume of voids / volume of solids.
Q2. Porosity is related to void ratio by
A) n = e/(1+e)
B) n = 1/(1+e)
C) n = e/(1−e)
D) n = 1/e
Ans: A
Explanation: Standard relation between n and e.
Q3. Degree of saturation is
A) Vw/Vs
B) Vw/Vv
C) Vv/V
D) Va/V
Ans: B
Explanation: Ratio of volume of water to volume of voids.
Q4. Typical specific gravity of soil solids is
A) 1.2
B) 2.0
C) 2.65
D) 4.0
Ans: C
Explanation: Most mineral soils have G ≈ 2.65.
Q5. For dry soil, which phase is absent?
A) Solid
B) Air
C) Water
D) Void
Ans: C
Explanation: Dry soil has solids + air only.
Q6. Bulk unit weight includes
A) Solids only
B) Solids + air
C) Solids + water
D) Solids + water + air
Ans: D
Explanation: Bulk unit weight considers all phases.
Q7. Submerged unit weight is
A) γsat − γw
B) γd + γw
C) γw − γsat
D) γsat + γw
Ans: A
Explanation: Effective weight in water = saturated − water.
Q8. If void ratio increases, soil becomes
A) Dense
B) Loose
C) Hard
D) Cemented
Ans: B
Explanation: Higher void ratio → more empty space.
Q9. Water content is ratio of
A) Ww/Ws
B) Ww/W
C) Vw/Vs
D) Vv/Vs
Ans: A
Explanation: Standard definition.
Q10. Three phases of soil are
A) Solid–liquid–gas
B) Solid–water–air
C) Rock–soil–water
D) Air–sand–clay
Ans: B
Explanation: Engineering soil system.
Q11. Air content is zero when soil is
A) Dry
B) Moist
C) Saturated
D) Submerged
Ans: C
Explanation: Saturated soil has no air.
Q12. Which parameter mostly affects compressibility?
A) Void ratio
B) Specific gravity
C) Unit weight
D) Water content
Ans: A
Explanation: Higher void ratio → more compression.
Q13. If porosity is 50%, void ratio is
A) 0.5
B) 1.0
C) 1.5
D) 2.0
Ans: B
Explanation: n = e/(1+e) ⇒ e = 1.
Q14. Unit weight of water is
A) 9.81 kN/m³
B) 10 kN/m³
C) 1 kN/m³
D) 1000 kN/m³
Ans: A
Explanation: Standard value.
Q15. Which soil parameter decides permeability most?
A) Shape
B) Grain size
C) Colour
D) Odour
Ans: B
Explanation: Larger grains → higher permeability.
🔹 TOPIC 2: SOIL CLASSIFICATION (Q16–Q30)
Q16. Soil classification mainly helps in
A) Transportation
B) Predicting behaviour
C) Costing
D) Excavation
Ans: B
Explanation: Classification links soil type with engineering use.
Q17. In India, soil classification is based on
A) AASHTO
B) BIS system
C) British system
D) USDA
Ans: B
Q18. Coarse-grained soils have more than
A) 50% passing 75 μm
B) 50% retained on 75 μm
C) 75% passing 4.75 mm
D) 25% passing 75 μm
Ans: B
Q19. Gravel size is
A) > 4.75 mm
B) < 0.075 mm
C) 0.075–4.75 mm
D) > 2 mm
Ans: A
Q20. Plasticity index =
A) LL − SL
B) LL − PL
C) PL − SL
D) WL − PL
Ans: B
Q21. Soil with PI = 0 is
A) Clay
B) Silt
C) Sand
D) Non-plastic
Ans: D
Q22. Which chart is used to classify fine soils?
A) Mohr circle
B) Casagrande chart
C) Flow net
D) Stress path
Ans: B
Q23. CH represents
A) Low plastic clay
B) High plastic clay
C) Low plastic silt
D) High plastic silt
Ans: B
Q24. Highly compressible soil is
A) Sand
B) Gravel
C) Clay
D) Silt
Ans: C
Q25. Well-graded soil has
A) Uniform size
B) Wide range of sizes
C) Only fine grains
D) Only coarse grains
Ans: B
Q26. Expansive soil is generally
A) Sand
B) Gravel
C) Clay
D) Silt
Ans: C
Q27. Black cotton soil mainly contains
A) Kaolinite
B) Illite
C) Montmorillonite
D) Quartz
Ans: C
Q28. Best soil for foundation is
A) Organic soil
B) Clay
C) Well-graded sand
D) Silt
Ans: C
Q29. Uniformly graded soil has
A) Cu > 4
B) Cu ≈ 1
C) Cu > 10
D) Cu < 0.5
Ans: B
Q30. Organic soils are unsuitable because they are
A) Strong
B) Stable
C) Compressible
D) Dense
Ans: C
🔹 TOPIC 3: ATTERBERG LIMITS (Q31–Q45)
Q31. Liquid limit is the water content at which soil changes from
A) Solid → semi-solid
B) Semi-solid → plastic
C) Plastic → liquid
D) Liquid → gas
Ans: C
Q32. Plastic limit is obtained by
A) Casagrande cup
B) Cone penetration
C) Rolling threads
D) Compaction
Ans: C
Q33. Shrinkage limit is when further drying causes
A) Volume decrease
B) No volume change
C) Volume increase
D) Weight increase
Ans: B
Q34. PI indicates
A) Density
B) Strength
C) Plasticity range
D) Permeability
Ans: C
Q35. Soil with high PI is
A) Sand
B) Silt
C) Clay
D) Gravel
Ans: C
Q36. LL > 50% indicates
A) Low plastic soil
B) Medium plastic soil
C) High plastic soil
D) Non-plastic soil
Ans: C
Q37. Which test finds LL?
A) Proctor test
B) Casagrande test
C) Permeability test
D) Shear test
Ans: B
Q38. Plasticity chart separates
A) Sand and gravel
B) Clay and silt
C) Organic and inorganic
D) Fine and coarse
Ans: B
Q39. If PI = 5, soil is
A) Highly plastic
B) Moderately plastic
C) Slightly plastic
D) Non-plastic
Ans: C
Q40. Shrinkage ratio is
A) ΔV/Δw
B) ΔV/V
C) Δw/ΔV
D) W/V
Ans: A
Q41. High LL means
A) Low compressibility
B) High compressibility
C) High permeability
D) High strength
Ans: B
Q42. PL corresponds to
A) Start of flow
B) Start of cracking
C) Crumbling of 3 mm thread
D) Maximum shrinkage
Ans: C
Q43. At SL soil becomes
A) Brittle
B) Elastic
C) Plastic
D) Liquid
Ans: A
Q44. Flow index is slope of
A) Compaction curve
B) Flow curve
C) Stress–strain curve
D) Permeability curve
Ans: B
Q45. Toughness index is
A) PI/FI
B) FI/PI
C) LL/PL
D) SL/LL
Ans: A
🔹 TOPIC 4: PERMEABILITY & SEEPAGE (Q46–Q60)
Q46. Darcy’s law is valid for
A) Turbulent flow
B) Laminar flow
C) Capillary flow
D) Seepage failure
Ans: B
Q47. Unit of permeability is
A) m²
B) m/s
C) N/m²
D) kg/m³
Ans: B
Q48. Highest permeability soil is
A) Clay
B) Silt
C) Sand
D) Gravel
Ans: D
Q49. Constant head test suits
A) Clay
B) Silt
C) Sand
D) Peat
Ans: C
Q50. Falling head test suits
A) Gravel
B) Sand
C) Clay
D) Coarse sand
Ans: C
Q51. Seepage velocity equals
A) Discharge velocity × porosity
B) Discharge velocity / porosity
C) Discharge velocity × e
D) Same as discharge velocity
Ans: B
Q52. Critical hydraulic gradient occurs when
A) Soil dries
B) Soil boils
C) Soil compacts
D) Soil cracks
Ans: B
Q53. Piping failure is due to
A) High load
B) High seepage force
C) Low density
D) Shrinkage
Ans: B
Q54. Flow net consists of
A) Flow lines & equipotential lines
B) Stress lines
C) Contours
D) Velocity lines
Ans: A
Q55. Equipotential lines show
A) Direction of flow
B) Equal head
C) Equal velocity
D) Equal discharge
Ans: B
Q56. Quick sand condition when
A) i > ic
B) i < ic
C) i = 0
D) i < 1
Ans: A
Q57. Hydraulic gradient is
A) h/L
B) L/h
C) h×L
D) h²/L
Ans: A
Q58. Permeability mainly depends on
A) Colour
B) Shape
C) Grain size
D) Odour
Ans: C
Q59. Discharge through soil ∝
A) Area
B) Gradient
C) Permeability
D) All
Ans: D
Q60. Seepage force per unit volume is
A) γw i
B) γsat
C) γd
D) γsub
Ans: A
🔹 TOPIC 5: COMPACTION (Q61–Q75)
Q61. Compaction increases
A) Void ratio
B) Strength
C) Compressibility
D) Permeability
Ans: B
Q62. OMC is water content at
A) Max density
B) Min density
C) Saturation
D) Shrinkage
Ans: A
Q63. Proctor test gives
A) Permeability
B) OMC & MDD
C) Shear strength
D) Settlement
Ans: B
Q64. Increase in compaction energy causes
A) ↑ OMC
B) ↓ OMC
C) No change
D) Random change
Ans: B
Q65. Best roller for clay is
A) Smooth wheel
B) Sheep foot
C) Vibratory
D) Grid
Ans: B
Q66. Best roller for sand is
A) Sheep foot
B) Pneumatic
C) Vibratory
D) Grid
Ans: C
Q67. Dry density =
A) γ/(1+w)
B) γ×(1+w)
C) γ − w
D) γ×w
Ans: A
Q68. Zero air voids line shows
A) Max density
B) Saturation line
C) Min density
D) Porosity line
Ans: B
Q69. Field density is checked by
A) Sieve test
B) Core cutter
C) Triaxial test
D) Plate load test
Ans: B
Q70. Compaction reduces
A) Strength
B) Density
C) Void ratio
D) Stability
Ans: C
Q71. Heavy compaction gives
A) Lower MDD
B) Higher MDD
C) Same MDD
D) Zero MDD
Ans: B
Q72. For highway embankment, aim is
A) High permeability
B) Low density
C) High density
D) Low strength
Ans: C
Q73. Which soil needs maximum compaction effort?
A) Sand
B) Silt
C) Clay
D) Gravel
Ans: C
Q74. Compaction is a
A) Drainage process
B) Mechanical process
C) Chemical process
D) Biological process
Ans: B
Q75. OMC depends mainly on
A) Colour
B) Grain size
C) Mineralogy
D) Shape
Ans: C
🔹 TOPIC 6: SHEAR STRENGTH (Q76–Q90)
Q76. Shear strength depends on
A) Cohesion
B) Friction
C) Both
D) Density only
Ans: C
Q77. Mohr–Coulomb equation is
A) τ = σ
B) τ = c + σ tanφ
C) τ = σ tanφ
D) τ = c
Ans: B
Q78. For clean sand, cohesion is
A) High
B) Moderate
C) Zero
D) Negative
Ans: C
Q79. Best test for shear strength is
A) Permeability test
B) Direct shear test
C) Compaction test
D) Consolidation test
Ans: B
Q80. Triaxial test is better than direct shear because
A) Simpler
B) More accurate stress control
C) Cheaper
D) Faster
Ans: B
Q81. In undrained test, drainage is
A) Allowed
B) Not allowed
C) Partial
D) Controlled
Ans: B
Q82. Angle of internal friction depends mainly on
A) Particle shape
B) Colour
C) Moisture
D) Temperature
Ans: A
Q83. Clay has
A) High φ
B) Low φ
C) Zero φ
D) Infinite φ
Ans: B
Q84. Maximum shear strength is in
A) Loose sand
B) Dense sand
C) Soft clay
D) Silt
Ans: B
Q85. Unconfined compression test is for
A) Sand
B) Gravel
C) Clay
D) Silt
Ans: C
Q86. UCS value equals
A) 2c
B) c
C) φ
D) c/2
Ans: A
Q87. Shear failure occurs when
A) Stress > strength
B) Stress < strength
C) Stress = 0
D) Strength increases
Ans: A
Q88. In cohesive soil, shear strength mainly comes from
A) Friction
B) Cohesion
C) Density
D) Water
Ans: B
Q89. Quick shear test is
A) Consolidation test
B) Unconfined compression
C) Direct shear
D) Permeability
Ans: B
Q90. Factor of safety =
A) Stress/strength
B) Strength/stress
C) Load/area
D) Area/load
Ans: B
🔹 TOPIC 7: CONSOLIDATION & SETTLEMENT (Q91–Q100)
Q91. Consolidation occurs due to
A) Compression of solids
B) Expulsion of air
C) Expulsion of water
D) Evaporation
Ans: C
Q92. Consolidation is significant in
A) Sand
B) Gravel
C) Clay
D) Rock
Ans: C
Q93. Primary consolidation is due to
A) Soil creep
B) Water expulsion
C) Air expulsion
D) Elastic rebound
Ans: B
Q94. Secondary consolidation is due to
A) Drainage
B) Elastic deformation
C) Soil creep
D) Air movement
Ans: C
Q95. Terzaghi’s theory applies to
A) Sand
B) Clay
C) Gravel
D) Rock
Ans: B
Q96. Coefficient of consolidation depends on
A) Permeability
B) Compressibility
C) Both
D) Density only
Ans: C
Q97. Time for consolidation ∝
A) Thickness
B) Thickness²
C) 1/Thickness
D) √Thickness
Ans: B
Q98. Maximum settlement occurs in
A) Sand
B) Gravel
C) Clay
D) Rock
Ans: C
Q99. Consolidation test is called
A) Triaxial test
B) Oedometer test
C) Shear test
D) Plate load test
Ans: B
Q100. Immediate settlement is due to
A) Drainage
B) Elastic deformation
C) Creep
D) Consolidation
Ans: B