Engineering Geology Questions and Answers Part-2

1. The area not considered under the crust is ____________
a) Mountainous area
b) Continental area
c) Oceanic area
d) Glacial area

Answer: d
Explanation: The first the options, Mountainous, Continental and Oceanic areas are studied separately whereas Glacial area is not considered under study of the crust as such.

2. Which of the following about weathering is not true?
a) It is a natural process
b) Mechanical disintegration is involved
c) Chemical decomposition is involved
d) It is a rapid process

Answer: d
Explanation: Weathering is defined as, a natural process of in-situ mechanical disintegration and or chemical decomposition of the rocks of the crust of the Earth by certain physical and chemical agencies of the atmosphere. It is a very slow process.

3. The process that is not considered under mechanical weathering is _______
a) Carbonation
b) Temperature variation
c) Unloading
d) Insolation

Answer: a
Explanation: Carbonation is a chemical weathering process whereas the rest viz., temperature variation, unloading, insolation are processes of mechanical weathering.

4. What is the change in volume when water freezes?
a) 10% decrease
b) 20% increase
c) 20% decrease
d) 10% increase

Answer: d
Explanation: It is said that water on freezing undergoes an increase in its volume by about ten per cent. This is expansion is accompanied by the exertion of pressure.

5. The form of rock not found by freezing-thawing cycle is ________
a) Angular
b) Sub angular
c) Spherical
d) Irregular

Answer: c
Explanation: The frost formed fragments are angular, sub angular, irregular in outline and remain spread over the parent rock having flat surface or flat slopes. Spherical form or outline of rock doesn’t come into picture here.

6. The processes by which Scree deposits are formed are ________
a) Chemical attack
b) Exposure to sunlight
c) Water movement
d) Heaving and rolling

Answer: d
Explanation: If the original surface forms a significant slope, as is commonly the case in the hilly and mountainous regions, the frost fragments get heaved up from the crevices and cavities and then roll down the slope under the influence of gravity. Finally, the fragments accumulate at the base as heaps commonly called as Scree deposits.

7. What are the slopes covered by Scree called?
a) Scree slope
b) Frost slope
c) Talus slope
d) Trist slope

Answer: c
Explanation: The slopes covered by frost formed scree are often referred to as Talus slopes.

8. Where can one find the process of exudation occur?
a) Plains
b) Seashore
c) Hills
d) Waterfalls

Answer: b
Explanation: Exudation is a process similar to frost action but in this case disintegration takes place due to the formation of sodium chloride etc., within the cavities of rocks thereby causing disintegration. This process is seen in good measure in porous rocks near seashore.

9. The stress developed in the top layers of the rocks which disintegrate due to repeated variations in temperatures is ________
a) Tensile stress
b) Compressive stress
c) Shear stress
d) Bending stress

Answer: a
Explanation: Repeated variations in temperature experienced by a body of rock gradually break it into smaller pieces, especially in the top layers, by development of tensile stresses developing from alternate expansion and contraction.

10. Which of the following facts about Exfoliation is false?
a) It is the phenomenon of peeling off of curved shells from rocks
b) The change is accompanied by chemical weathering
c) Internal structure of the rock is affected
d) It occurs in thick or layered rocks.

Answer: c
Explanation: The internal structure of the rock is not affected due to the process of exfoliation. The phenomenon of peeling off occurs only in the layered or thick rocks and is accompanied by chemical weathering, mostly near the margins and develop curved surfaces. So basically surface is affected and not the internal structure.