1. In mural jointing, one set is horizontal and two sets are vertical.
a) True
b) False
Explanation: In granitic and other rock masses, there may occur three sets of joints in such a way that one set is horizontal and the other two sets are vertical, all the three sets being mutually perpendicular to each other.
2. The nature of sedimentary rock that can undergo some irregular jointing is ___________
a) Plastic in nature
b) Non-plastic in nature
c) Rich in moisture
d) Plastic in nature and rich in moisture
Explanation: Sedimentary rocks especially those of plastic nature and rich in moisture in the initial stage (clays, shales, limestones, dolomites etc.) undergo some contraction on drying up which might have resulted into irregular jointing.
3. Contraction or shrinkage is the cause of which joints?
a) Radial joints
b) Vertical joints
c) Sheet joints
d) Mural joints
Explanation: During the formation of igneous rocks, tensile forces are developed in them due to cooling and the force is strong enough to cause joints. Such contraction or shrinkage is generally, accepted to be the cause of the vertical type of joints in granites and the so well -known columnar joints of basalts and other effusive rocks.
4. A single theory is enough to explain origin of all types of joints.
a) True
b) False
Explanation: Joints are caused in different rocks due to different reasons. No single theory can explain origin of all types of joints.
5. The wide range of temperature which vary in arid climate is ___________
a) -10° to 100° C
b) 10° to 80° C
c) -50° to 60°C
d) 50° to 60° C
Explanation: Repeated expansion and contraction is characteristic of regions with dry hot (arid) climates where day and night temperatures on the one hand and summer and winter temperatures on the other hand vary within a very wide range of -50° to 60° C.
6. Removal of overburden causes ___________
a) Expansion
b) Contraction
c) Shrinkage
d) Rise
Explanation: Removal of overburden due to weathering or other processes of rock wasting may also cause expansion of the underlying rocks due to unloading. The previously loaded rocks get relaxed with the release of the forces.
7. Sheet joints in sedimentary rocks are attributed to ___________
a) Erosional loading
b) Erosional unloading
c) Weathering loading
d) Weathering unloading
Explanation: The sheet joints of sedimentary rocks and other rocks are attributed by many to the process of erosional unloading through geological ages.
8. What kind of impact do the joints have on activities of engineering?
a) Positive
b) Negative
c) No impact
d) Positive and negative
Explanation: Joints affect the properties of rocks both in a negative as well as positive manner with respect to the activities of a professional civil and mining engineer.
9. What is/are related to jointed rocks?
a) Earthquakes
b) Landslides
c) Slope failures
d) Landslides and slope failures
Explanation: Many landslides and slope failures are directly related to the jointed nature of the rocks. This is due to instability of rocks in hilly regions and the jointed rocks get easily lubricated in presence of moisture and start sliding or falling from their places.
10. First step of treatment of joints is ___________
a) Grouting
b) Filling with chemicals
c) Detailed investigation
d) Installing devices
Explanation: Treating the negative qualities of rocks due to joints will differ in different projects. The first requirement in all cases is, however, detailed investigations to establish full characteristics of the joints.