18-GEOL-A5 Rock Mechanics Exam B
Question 1. What is the primary scope of rock mechanics?
A) Study of soil behavior under static conditions
B) Investigation of rock behavior and response under various forces for
engineering purposes
C) Examination of mineral extraction techniques
D) Analysis of groundwater flow in porous media
Answer: B
Explanation: Rock mechanics focuses on understanding the behavior of
rocks under different stress conditions, crucial for engineering design
and safety assessments involving rock masses.
Question 2. Which historical figure is credited with developing the
Mohr-Coulomb failure criterion?
A) Albert Einstein
B) Charles-Augustin de Coulomb
C) Isaac Newton
D) Georges-Louis Leclerc
Answer: B
Explanation: Coulomb contributed to the development of the failure
criterion that combines shear and normal stresses to predict failure,
widely used in rock and soil mechanics.
, 18-GEOL-A5 Rock Mechanics Exam B
Question 3. Which mineral composition best characterizes a granite
rock?
A) Mainly quartz and feldspar with minor mica
B) Mostly calcite and aragonite
C) Primarily clay minerals
D) Dominated by olivine and pyroxene
Answer: A
Explanation: Granite is an igneous rock primarily composed of quartz,
feldspar, and mica, giving it a coarse-grained texture.
Question 4. Porosity in rocks refers to which of the following?
A) The weight of the rock per unit volume
B) The percentage of void space within the rock
C) The permeability of the rock to water flow
D) The mineral composition of the rock
Answer: B
Explanation: Porosity measures the volume of void spaces within a rock
relative to its total volume, indicating how much fluid a rock can store.
, 18-GEOL-A5 Rock Mechanics Exam B
Question 5. How does permeability differ from porosity?
A) Permeability measures mineral content, porosity measures water
content
B) Permeability indicates fluid flow capacity, porosity indicates void
space volume
C) They are synonyms in rock mechanics
D) Permeability measures density, porosity measures elastic properties
Answer: B
Explanation: Permeability quantifies the ability of a rock to transmit
fluids, while porosity indicates the amount of void space available in
the rock.
Question 6. Which property relates the density of a rock to its specific
gravity?
A) Density is always higher than specific gravity
B) Specific gravity is the ratio of the density of the rock to the density of
water
C) Density and specific gravity are unrelated
D) Specific gravity measures the elastic modulus of the rock
Answer: B
, 18-GEOL-A5 Rock Mechanics Exam B
Explanation: Specific gravity is the ratio of the density of the material to
the density of water, providing a dimensionless measure of density.
Question 7. Water content in rocks influences which mechanical
property?
A) Young’s modulus
B) Tensile strength
C) Shear strength
D) All of the above
Answer: D
Explanation: Water content affects various properties, including
stiffness (Young’s modulus), tensile, and shear strengths, often
weakening the rock.
Question 8. Which of the following best describes elastic behavior in
rocks?
A) Permanent deformation after load removal
B) Reversible deformation within the elastic limit
C) Irreversible deformation at low stresses
D) Brittle fracture without deformation
Question 1. What is the primary scope of rock mechanics?
A) Study of soil behavior under static conditions
B) Investigation of rock behavior and response under various forces for
engineering purposes
C) Examination of mineral extraction techniques
D) Analysis of groundwater flow in porous media
Answer: B
Explanation: Rock mechanics focuses on understanding the behavior of
rocks under different stress conditions, crucial for engineering design
and safety assessments involving rock masses.
Question 2. Which historical figure is credited with developing the
Mohr-Coulomb failure criterion?
A) Albert Einstein
B) Charles-Augustin de Coulomb
C) Isaac Newton
D) Georges-Louis Leclerc
Answer: B
Explanation: Coulomb contributed to the development of the failure
criterion that combines shear and normal stresses to predict failure,
widely used in rock and soil mechanics.
, 18-GEOL-A5 Rock Mechanics Exam B
Question 3. Which mineral composition best characterizes a granite
rock?
A) Mainly quartz and feldspar with minor mica
B) Mostly calcite and aragonite
C) Primarily clay minerals
D) Dominated by olivine and pyroxene
Answer: A
Explanation: Granite is an igneous rock primarily composed of quartz,
feldspar, and mica, giving it a coarse-grained texture.
Question 4. Porosity in rocks refers to which of the following?
A) The weight of the rock per unit volume
B) The percentage of void space within the rock
C) The permeability of the rock to water flow
D) The mineral composition of the rock
Answer: B
Explanation: Porosity measures the volume of void spaces within a rock
relative to its total volume, indicating how much fluid a rock can store.
, 18-GEOL-A5 Rock Mechanics Exam B
Question 5. How does permeability differ from porosity?
A) Permeability measures mineral content, porosity measures water
content
B) Permeability indicates fluid flow capacity, porosity indicates void
space volume
C) They are synonyms in rock mechanics
D) Permeability measures density, porosity measures elastic properties
Answer: B
Explanation: Permeability quantifies the ability of a rock to transmit
fluids, while porosity indicates the amount of void space available in
the rock.
Question 6. Which property relates the density of a rock to its specific
gravity?
A) Density is always higher than specific gravity
B) Specific gravity is the ratio of the density of the rock to the density of
water
C) Density and specific gravity are unrelated
D) Specific gravity measures the elastic modulus of the rock
Answer: B
, 18-GEOL-A5 Rock Mechanics Exam B
Explanation: Specific gravity is the ratio of the density of the material to
the density of water, providing a dimensionless measure of density.
Question 7. Water content in rocks influences which mechanical
property?
A) Young’s modulus
B) Tensile strength
C) Shear strength
D) All of the above
Answer: D
Explanation: Water content affects various properties, including
stiffness (Young’s modulus), tensile, and shear strengths, often
weakening the rock.
Question 8. Which of the following best describes elastic behavior in
rocks?
A) Permanent deformation after load removal
B) Reversible deformation within the elastic limit
C) Irreversible deformation at low stresses
D) Brittle fracture without deformation
