MAE 201 Final Exam Review NCSU
Questions With Verified Answers ||
100% pass
Question 1. A reversible process returns the working f
A. True
B. False
Correct Answer: B
Rationale: A reversible process is one that can be reversed without leaving
any net change in the system or surroundings; it does not simply mean
returning the working fluid to its initial state. A cyclic process returns the
working fluid to its initial state, regardless of whether it is reversible.
Question 2. Entropy generation is a property.
A. True
B. False
Correct Answer: B
Rationale: Entropy generation is not a property; it is a measure of the
irreversibilities that occur during a process. A property is a characteristic
of a system in a given state, independent of the path taken to reach that
state.
,Question 3. An isentropic process is an ideal process with no heat transfer.
A. True
B. False
Correct Answer: A
Rationale: An isentropic process is both adiabatic (no heat transfer) and
reversible, which makes it an ideal process. Internally, the entropy
remains constant (s₁ = s₂).
Question 4. The purpose of a refrigerator is to remove heat from a high-
temperature area.
A. True
B. False
Correct Answer: B
Rationale: The purpose of a refrigerator is to remove heat from a low-
temperature area (the refrigerated space) and reject it to a high-
temperature area (the surroundings). It requires work input to move heat
“uphill” against the natural temperature gradient.
Question 5. The second law of thermodynamics states that all real
processes must occur in the direction that generates entropy.
A. True
B. False
,Correct Answer: A
Rationale: The second law dictates that for any real (irreversible) process,
the total entropy of the system and its surroundings must increase. Only
in a reversible ideal process does entropy remain constant.
Question 6. What classifies a reversible process?
A. A process that is perfectly isothermal
B. A process that returns the system to its initial state
C. A process that can be reversed without increasing entropy
D. A process with no heat transfer
Correct Answer: C
Rationale: A reversible process is an idealization where the system and
surroundings can be returned to their original states with no net increase
in entropy. It requires the system to be in near-equilibrium at all times and
is realistically impossible.
Question 7. What makes something a property?
A. It must be independent of the amount of mass
B. It must be path-independent and depend only on the state
C. It must be a measure of energy transfer
D. It must change only during reversible processes
Correct Answer: B
Rationale: A property is any characteristic of a system that depends only
on its state (e.g., temperature, pressure, volume, mass) and not on the
, path taken to reach that state. Properties can be intensive (independent of
mass) or extensive (dependent on mass).
Question 8. What makes something an “ideal” process?
A. It occurs infinitely fast
B. It involves no work interactions
C. Its direction can be reversed by infinitesimal changes, with no entropy
increase
D. It happens at constant pressure
Correct Answer: C
Rationale: An ideal process is a reversible process, meaning that it can be
reversed by making infinitesimal changes in the surroundings, and it
produces no entropy. It is a theoretical benchmark for real processes.
Section A: Fundamentals of Thermodynamics (Questions 9–40)
Question 9. Which of the following is an extensive property?
A. Temperature
B. Pressure
C. Density
D. Volume
Correct Answer: D
Questions With Verified Answers ||
100% pass
Question 1. A reversible process returns the working f
A. True
B. False
Correct Answer: B
Rationale: A reversible process is one that can be reversed without leaving
any net change in the system or surroundings; it does not simply mean
returning the working fluid to its initial state. A cyclic process returns the
working fluid to its initial state, regardless of whether it is reversible.
Question 2. Entropy generation is a property.
A. True
B. False
Correct Answer: B
Rationale: Entropy generation is not a property; it is a measure of the
irreversibilities that occur during a process. A property is a characteristic
of a system in a given state, independent of the path taken to reach that
state.
,Question 3. An isentropic process is an ideal process with no heat transfer.
A. True
B. False
Correct Answer: A
Rationale: An isentropic process is both adiabatic (no heat transfer) and
reversible, which makes it an ideal process. Internally, the entropy
remains constant (s₁ = s₂).
Question 4. The purpose of a refrigerator is to remove heat from a high-
temperature area.
A. True
B. False
Correct Answer: B
Rationale: The purpose of a refrigerator is to remove heat from a low-
temperature area (the refrigerated space) and reject it to a high-
temperature area (the surroundings). It requires work input to move heat
“uphill” against the natural temperature gradient.
Question 5. The second law of thermodynamics states that all real
processes must occur in the direction that generates entropy.
A. True
B. False
,Correct Answer: A
Rationale: The second law dictates that for any real (irreversible) process,
the total entropy of the system and its surroundings must increase. Only
in a reversible ideal process does entropy remain constant.
Question 6. What classifies a reversible process?
A. A process that is perfectly isothermal
B. A process that returns the system to its initial state
C. A process that can be reversed without increasing entropy
D. A process with no heat transfer
Correct Answer: C
Rationale: A reversible process is an idealization where the system and
surroundings can be returned to their original states with no net increase
in entropy. It requires the system to be in near-equilibrium at all times and
is realistically impossible.
Question 7. What makes something a property?
A. It must be independent of the amount of mass
B. It must be path-independent and depend only on the state
C. It must be a measure of energy transfer
D. It must change only during reversible processes
Correct Answer: B
Rationale: A property is any characteristic of a system that depends only
on its state (e.g., temperature, pressure, volume, mass) and not on the
, path taken to reach that state. Properties can be intensive (independent of
mass) or extensive (dependent on mass).
Question 8. What makes something an “ideal” process?
A. It occurs infinitely fast
B. It involves no work interactions
C. Its direction can be reversed by infinitesimal changes, with no entropy
increase
D. It happens at constant pressure
Correct Answer: C
Rationale: An ideal process is a reversible process, meaning that it can be
reversed by making infinitesimal changes in the surroundings, and it
produces no entropy. It is a theoretical benchmark for real processes.
Section A: Fundamentals of Thermodynamics (Questions 9–40)
Question 9. Which of the following is an extensive property?
A. Temperature
B. Pressure
C. Density
D. Volume
Correct Answer: D
