# Basic Civil Engineering Questions and Answers – Soil Properties

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This set of Basic Civil Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Soil Properties”.

1. Most soils have a particle density of about:
a) 2.6 g/cc
b) 2.9 g/cc
c) 2.5 g/cc
d) 2.7 g/cc

Explanation: Particle density is mass per unit volume of soil particles. It is expressed in g/cc and most soils have 2.6 g/cc as particle density.

2. Soil exists in how many states?
a) 1
b) 2
c) 3
d) 4

Explanation: Soil can exist in four states based on the amount of water content. They are liquid, plastic, semi solid and solid state. Water content decreases with each state.

3. In oven drying method for determination of water content, temperature maintained is:
a) 100-105oC
b) 150-160oC
c) 105-110oC
d) 110-120oC

Explanation: An optimum and constant temperature of 105-110oC is to be maintained in the oven. The specimen is kept for about 24 hours to ensure proper drying.

4. A soil generally consists of combination of __________ separates.
a) 2
b) 3
c) 4
d) 5

Explanation: The mineral components of soil are termed as separates. These are three of them – clay, silt and sand. Various soils are designated based on the proportion of separates.

5. Loose soil has a relative density within a range of:
a) 60-85
b) 85-100
c) 10-35
d) 35-60

Explanation: Relative density is used to express relative compactness of cohesionless soil. It ranges from <10 to 100 (very loose to very dense). Loose soil has a relative density between 10 and 35.

6. _________ apparatus is used to test liquid limit of a soil.
a) Mohr
b) Casagrande
c) Otto
d) Terzaghi

Explanation: The water content at which soil changes from liquid to plastic state is liquid limit. Casagrande apparatus consists of a rubber base and brass cup. Sample is filled in a cup, subjected to blows by rotating handle at 2 revolutions per second. Water content corresponding to 25 blows is the liquid limit.

7. How many tests in the lab can be performed to get permeability of soil?
a) 5
b) 4
c) 3
d) 2

Explanation: The two tests are constant head permeability test and variable head permeability test. The constant head permeability test is done for highly permeable soil and the other one for fine grained soil.

8. Soil with higher Ic (consistency index) is a better foundation material.
a) True
b) False

Explanation: If two soils are to be compared, based on Ic, then higher value one is better foundation material. If Ic < 0, natural water content < liquid limit and soil would behave like liquid. This is not a desired property for foundation material.

9. How many types of pores are present in a soil mass?
a) 6
b) 3
c) 5
d) 4

Explanation: The five types are macropore (too large, >75μm), mesopore (30-75μm), micropore (5-30μm), ultramicropore (0.1-30μm) and cryptopore (smallest, < 0.1 μm).

10. How many grades of soil are there?
a) 5
b) 4
c) 7
d) 6