21. The dry density of a compacted soil can be increased by: A. Increasing compactive effort B. Increasing water beyond optimum C. Reducing compactive energy D. Decreasing particle size Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Increasing compactive effort improves particle arrangement and reduces voids, increasing dry density up to a limit.
22. Which type of soil has negligible cohesion? A. Gravel B. Clay C. Organic soil D. Loam Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Gravel is a coarse-grained soil with no cohesion.It derives strength primarily from interparticle friction.
23. What happens to soil permeability as compaction increases? A. Increases B. Remains same C. Decreases D. Fluctuates Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Compaction reduces void spaces, thereby decreasing permeability and slowing water flow through soil.
24. The consistency index is calculated using: A. Plastic and liquid limits B. Dry density and moisture C. Shear strength D. Porosity Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Consistency index (Ic) = (Liquid limit - Natural water content) / (Plasticity index).It measures the firmness of soil in its natural state.
25. Which of the following has the highest permeability? A. Clay B. Silt C. Loam D. Gravel Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D Solution: Gravel has large, interconnected pores, resulting in high permeability.It allows rapid water movement.
26. Which method is used to determine the moisture content of soil? A. Casagrande test B. Pycnometer method C. Constant head test D. Vane shear test Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: The pycnometer method is a standard lab technique used to determine moisture content in soil samples.
27. The unconfined compressive strength (UCS) test is best suited for: A. Non-cohesive soils B. Saturated sands C. Stiff clays D. Silts Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: The UCS test is performed without lateral confinement and is most applicable for cohesive soils like stiff clays.
28. Plasticity index of soil is: A. Liquid limit + Plastic limit B. Liquid limit - Plastic limit C. Liquid limit / Plastic limit D. Plastic limit - Shrinkage limit Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: Plasticity index (PI) = Liquid limit - Plastic limitIt indicates the range of moisture content where the soil behaves plastically.
29. In the compaction curve, the peak point represents: A. Liquid limit B. Optimum moisture content C. Plastic limit D. Shear strength Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: The peak of the compaction curve indicates the optimum moisture content, which gives the highest dry density.
30. The slope of the e-log p curve in a consolidation test gives: A. Compression index B. Cohesion C. Void ratio D. Saturation Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: The compression index (Cc) is the slope of the e-log p curve, representing the compressibility of soil during primary consolidation.
