51. Liquidity index is a measure of: A. Soil saturation B. Compressibility C. Relative consistency D. Organic content Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Liquidity index (LI) shows how close a soil's moisture is to its liquid limit.LI = (Natural water content - Plastic limit) / (Liquid limit - Plastic limit).
52. Compaction improves soil by: A. Reducing density B. Increasing permeability C. Increasing voids D. Increasing shear strength Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D Solution: Compaction increases shear strength and stability by reducing air voids and densifying the soil mass.
53. Soil consolidation is due to: A. Reduction in air content B. Increase in moisture C. Decrease in temperature D. Expulsion of water from pores Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D Solution: Consolidation is the gradual decrease in volume of a saturated soil due to the expulsion of water from its pores under load.
54. What is the effect of organic matter on soil strength? A. Increases strength B. No effect C. Decreases strength D. Increases cohesion Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Organic matter interferes with soil structure and bonding, leading to reduced strength and load-bearing capacity.
55. What does a high void ratio indicate? A. Dense soil B. Strong soil C. Loose soil D. Expansive soil Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: A high void ratio indicates that the soil is loose with more air and water spaces, reducing strength and stability.
56. Which property is measured in a Proctor test? A. Plasticity B. Permeability C. Dry density D. Grain size Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: The Proctor test determines the maximum dry density and optimum moisture content for compaction of soils.
57. The angle of internal friction is most relevant to: A. Clayey soils B. Organic soils C. Cohesionless soils D. Expansive soils Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Angle of internal friction quantifies shear strength in cohesionless soils like sand due to interparticle friction.
58. Which factor affects soil permeability the most? A. Soil structure B. Clay content C. Particle size distribution D. Organic matter Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Particle size distribution greatly affects permeability: coarse soils (e.g., sand) allow water to pass quickly, fine soils (e.g., clay) restrict it.
59. Which instrument is used to determine the liquid limit of soil? A. Hydrometer B. Casagrande apparatus C. Triaxial cell D. Compaction mold Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: The Casagrande apparatus is used to determine the liquid limit of soils through repeated blows in a standard cup until closure.
60. The shrinkage limit of soil is defined as the: A. Water content below which soil shrinks B. Lowest moisture content before cracking C. Water content at plastic state D. Moisture content at maximum volume Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Shrinkage limit is the lowest moisture content at which a soil can be dried without further volume reduction.Below this, no more shrinkage occurs.