250+ TOP MCQs on Soils – Textural Classification and Answers

Geotechnical Engineering Multiple Choice Questions on “Soils – Textural Classification”.

1. Soil classification based on the particle size distribution is _____________
a) Unified soil classification
b) IS classification
c) Particle size classification
d) Textural classification
Answer: d
Clarification: Soil classification of composite soils exclusively based on the particle size distribution is known as textural classification.

2. The best known classification system in textural classification is __________
a) M.I.T. classification system
b) Triangular classification of U.S. public road administration
c) Indian classification system
d) International classification
Answer: b
Clarification: Triangular classification of U.S. public road administration is a commonly used system for textural classification.

3. Textural classification is most suitable for ____________
a) Clay soil
b) Wet soil
c) Coarse grained soil
d) Soil with moist
Answer: c
Clarification: Since the textural classification is based on the percentages of sand, silt, and clay size making up the soil. Such a classification is more suitable for describing coarse-grained soil.

4. To use textural classification chart ___________ lines must be drawn.
a) Parallel to the three sides of the triangle
b) Parallel to the only one side of the triangle
c) Adjacent to the three sides of the triangle
d) Adjacent to the one sides of the triangle
Answer: a
Clarification: To use the textural classification chart, for a given percentage of three constituents forming a soil, lines are drawn parallel to three sides of the equilateral triangle.

5. The type of triangle, used in textural classification of soil is _____________
a) Right angled triangle
b) Equilateral triangle
c) Perpendicular triangle
d) None of the mentioned
Answer: b
Clarification: A triangle, having equal length of sides (i.e. Equilateral triangle) is used in textural classification chart.

6. Public road administration (PRA) system is based on _____________
a) Particle-size composition and Plasticity characteristics
b) Particle size distribution
c) All of the mentioned
d) None of the mentioned
Answer: a
Clarification: HRB classification system, also known as public road administration (PRA) is based on both the particle-size composition and plasticity characteristics.

7. Highway research board (HRB) classification system is also known as__________
a) Indian classification system
b) Public road administration (PRA) system
c) International classification system
d) M.I.T. classification system
Answer: b
Clarification: Highway research board classification system is also known as public road administration (PRA) system.

8. Based on HRB classification system, the soil are divided in to ___________
a) 2 primary groups
b) 6 primary groups
c) 7 primary groups
d) 6 primary groups
Answer: c
Clarification: Based on HRB system, the soil is divided into 7 primary groups, designated as A-1, A-2…A-7.

9. The performance of the soil, when used for pavement construction is found out by using _____________
a) Quality test
b) Group index
c) Material test
d) None of the mentioned
Answer: b
Clarification: As group index is a mean of rating the value of soil as a sub-grade material. It can be used for finding the performance and quality of the soil.

10. The group index of a soil depends on ____________
a) Liquid limit
b) Plastic limit
c) All of the mentioned
d) None of the mentioned
Answer: a
Clarification: Group index of soil usually varies by
i. Liquid limit
ii. Plastic limit
iii. Amount of material passing through the 75-micron IS sieve.

11. Group index is defined by which of the equation?
a) GI=0.2b+0.005ac+0.01bd
b) GI=0.2a+0.005bd+0.001ac
c) GI=0.2a+0.005ac+0.001bd
d) GI=0.2a+0.5ac+0.001bd
Answer: c
Clarification: Group index (GI) is given by the following equation
GI = 0.2a+0.005ac+0.01bd.

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