NICET Construction Materials Testing –
Soils Level III Practice Exam Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. Which soil classification system is most commonly used for
engineering purposes in the United States?
A. AASHTO
B. USDA
C. Unified Soil Classification System (USCS)
D. ISO
Answer: C
USCS is the primary system used by engineers to classify soils based
on grain size distribution and plasticity characteristics.
2. In the USCS, a soil classified as CL is best described as:
A. Low plasticity silt
, B. High plasticity clay
C. Low plasticity clay
D. Organic clay
Answer: C
CL indicates inorganic clay with low plasticity according to Atterberg
limits.
3. Which laboratory test is used to determine the liquid limit of a soil?
A. Proctor test
B. Casagrande cup or fall cone test
C. Hydrometer analysis
D. Direct shear test
Answer: B
The liquid limit is determined using either the Casagrande apparatus
or the fall cone method.
4. The plasticity index (PI) is calculated as:
A. LL + PL
B. PL – LL
C. LL – PL
D. LL ÷ PL
Answer: C
PI represents the range of moisture contents over which the soil
remains plastic.
,5. Which soil property is most directly related to shear strength?
A. Permeability
B. Compressibility
C. Cohesion and angle of internal friction
D. Specific gravity
Answer: C
Shear strength depends on soil cohesion and friction angle.
6. A Proctor compaction test determines the relationship between:
A. Moisture content and permeability
B. Density and grain size
C. Moisture content and dry density
D. Load and settlement
Answer: C
The Proctor test establishes the optimum moisture content and
maximum dry density.
7. Which compaction test uses higher compactive effort?
A. Standard Proctor
B. Modified Proctor
C. California Bearing Ratio
D. Atterberg limits
Answer: B
The Modified Proctor applies greater energy, simulating heavier field
compaction.
, 8. Field density of compacted soil is commonly measured using:
A. Sieve analysis
B. Nuclear density gauge
C. Triaxial test
D. Hydrometer test
Answer: B
Nuclear gauges are widely used for rapid field density and moisture
measurements.
9. When using a nuclear density gauge, which safety practice is required?
A. Wearing steel-toe boots
B. Proper radiation safety training and licensing
C. Daily calibration by a lab
D. Keeping it underground
Answer: B
Nuclear gauges contain radioactive sources and require licensed
operators.
10. The California Bearing Ratio (CBR) test is primarily used to
evaluate:
A. Soil classification
B. Subgrade strength for pavement design
C. Soil permeability
D. Soil plasticity
Answer: B
Soils Level III Practice Exam Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which soil classification system is most commonly used for
engineering purposes in the United States?
A. AASHTO
B. USDA
C. Unified Soil Classification System (USCS)
D. ISO
Answer: C
USCS is the primary system used by engineers to classify soils based
on grain size distribution and plasticity characteristics.
2. In the USCS, a soil classified as CL is best described as:
A. Low plasticity silt
, B. High plasticity clay
C. Low plasticity clay
D. Organic clay
Answer: C
CL indicates inorganic clay with low plasticity according to Atterberg
limits.
3. Which laboratory test is used to determine the liquid limit of a soil?
A. Proctor test
B. Casagrande cup or fall cone test
C. Hydrometer analysis
D. Direct shear test
Answer: B
The liquid limit is determined using either the Casagrande apparatus
or the fall cone method.
4. The plasticity index (PI) is calculated as:
A. LL + PL
B. PL – LL
C. LL – PL
D. LL ÷ PL
Answer: C
PI represents the range of moisture contents over which the soil
remains plastic.
,5. Which soil property is most directly related to shear strength?
A. Permeability
B. Compressibility
C. Cohesion and angle of internal friction
D. Specific gravity
Answer: C
Shear strength depends on soil cohesion and friction angle.
6. A Proctor compaction test determines the relationship between:
A. Moisture content and permeability
B. Density and grain size
C. Moisture content and dry density
D. Load and settlement
Answer: C
The Proctor test establishes the optimum moisture content and
maximum dry density.
7. Which compaction test uses higher compactive effort?
A. Standard Proctor
B. Modified Proctor
C. California Bearing Ratio
D. Atterberg limits
Answer: B
The Modified Proctor applies greater energy, simulating heavier field
compaction.
, 8. Field density of compacted soil is commonly measured using:
A. Sieve analysis
B. Nuclear density gauge
C. Triaxial test
D. Hydrometer test
Answer: B
Nuclear gauges are widely used for rapid field density and moisture
measurements.
9. When using a nuclear density gauge, which safety practice is required?
A. Wearing steel-toe boots
B. Proper radiation safety training and licensing
C. Daily calibration by a lab
D. Keeping it underground
Answer: B
Nuclear gauges contain radioactive sources and require licensed
operators.
10. The California Bearing Ratio (CBR) test is primarily used to
evaluate:
A. Soil classification
B. Subgrade strength for pavement design
C. Soil permeability
D. Soil plasticity
Answer: B
