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Georgia Mechanical Engineer
Examination Advanced Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. A vapor-compression refrigeration system operates with a condenser
pressure of 1.2 MPa and an evaporator pressure of 0.25 MPa. Which
component primarily controls the pressure drop between these two
pressure levels?
A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
Answer: C. Expansion valve
Rationale: The expansion valve meters refrigerant into the evaporator and
creates the pressure reduction from the high-pressure liquid side to the low-
pressure evaporator side.
2. In an ideal Brayton cycle, increasing the compressor pressure ratio while
maintaining turbine inlet temperature generally has what effect on thermal
efficiency?
,A. Decreases efficiency continuously
B. Increases efficiency within the practical operating range
C. Has no effect
D. Makes efficiency equal to zero
Answer: B. Increases efficiency within the practical operating range
Rationale: For an ideal Brayton cycle, increasing pressure ratio generally
increases thermal efficiency, although real systems experience additional losses
and temperature limitations.
3. A centrifugal pump experiences cavitation when the pressure at the pump
suction falls below the liquid's vapor pressure. Which parameter is most
directly used to assess resistance to cavitation?
A. Brake horsepower
B. NPSH available
C. Reynolds number
D. Hydraulic radius
Answer: B. NPSH available
Rationale: Net positive suction head available must exceed the pump's required
NPSH by an adequate margin to prevent cavitation.
4. Air enters a cooling coil at 80°F dry-bulb and 67°F wet-bulb temperature
and leaves at 55°F saturated. What type of process most closely represents
the air-side coil process?
A. Sensible heating only
B. Sensible cooling and dehumidification
C. Humidification only
D. Adiabatic compression
Answer: B. Sensible cooling and dehumidification
Rationale: Cooling air below its dew-point temperature causes moisture
condensation while the dry-bulb temperature decreases.
, 5. For fully developed laminar flow through a circular pipe, the Darcy friction
factor is:
A. 16/Re
B. 32/Re
C. 64/Re
D. 0.316/Re^0.25
Answer: C. 64/Re
Rationale: For fully developed laminar flow in a circular pipe, the Darcy friction
factor is exactly 64 divided by the Reynolds number.
6. A steel pressure vessel has an internal diameter of 48 in. and wall thickness
of 0.50 in. If the internal pressure is 200 psi, the approximate hoop stress
using the thin-wall relation is:
A. 2,400 psi
B. 4,800 psi
C. 9,600 psi
D. 19,200 psi
Answer: C. 9,600 psi
Rationale: For a thin cylindrical vessel, hoop stress is σ = pD/(2t) =
(200)(48)/(2×0.50) = 9,600 psi.
7. A heat exchanger has a hot-fluid inlet temperature of 350°F and outlet
temperature of 250°F. The cold fluid enters at 100°F and leaves at 200°F.
For counterflow operation, the log mean temperature difference is:
A. 75°F
B. 100°F
C. 150°F
D. 200°F
Answer: C. 150°F
, Rationale: The terminal temperature differences are 350−200 = 150°F and
250−100 = 150°F. When both terminal differences are equal, the LMTD is 150°F.
8. Which nondimensional number compares inertial forces to viscous forces in
fluid flow?
A. Mach number
B. Reynolds number
C. Prandtl number
D. Froude number
Answer: B. Reynolds number
Rationale: Reynolds number represents the ratio of inertial forces to viscous
forces and is widely used to characterize laminar and turbulent flow.
9. In a closed hydronic heating system, an expansion tank is primarily installed
to:
A. Increase pump head
B. Remove dissolved oxygen
C. Accommodate thermal expansion of the water
D. Increase boiler efficiency
Answer: C. Accommodate thermal expansion of the water
Rationale: Water expands as its temperature increases. The expansion tank
provides a compressible volume that accommodates this expansion and limits
pressure fluctuations.
10.For a reciprocating internal-combustion engine, volumetric efficiency
primarily measures:
A. Ratio of actual inducted air to theoretical displacement volume
B. Mechanical friction losses
C. Fuel heating value
D. Brake power divided by indicated power
Georgia Mechanical Engineer
Examination Advanced Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. A vapor-compression refrigeration system operates with a condenser
pressure of 1.2 MPa and an evaporator pressure of 0.25 MPa. Which
component primarily controls the pressure drop between these two
pressure levels?
A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
Answer: C. Expansion valve
Rationale: The expansion valve meters refrigerant into the evaporator and
creates the pressure reduction from the high-pressure liquid side to the low-
pressure evaporator side.
2. In an ideal Brayton cycle, increasing the compressor pressure ratio while
maintaining turbine inlet temperature generally has what effect on thermal
efficiency?
,A. Decreases efficiency continuously
B. Increases efficiency within the practical operating range
C. Has no effect
D. Makes efficiency equal to zero
Answer: B. Increases efficiency within the practical operating range
Rationale: For an ideal Brayton cycle, increasing pressure ratio generally
increases thermal efficiency, although real systems experience additional losses
and temperature limitations.
3. A centrifugal pump experiences cavitation when the pressure at the pump
suction falls below the liquid's vapor pressure. Which parameter is most
directly used to assess resistance to cavitation?
A. Brake horsepower
B. NPSH available
C. Reynolds number
D. Hydraulic radius
Answer: B. NPSH available
Rationale: Net positive suction head available must exceed the pump's required
NPSH by an adequate margin to prevent cavitation.
4. Air enters a cooling coil at 80°F dry-bulb and 67°F wet-bulb temperature
and leaves at 55°F saturated. What type of process most closely represents
the air-side coil process?
A. Sensible heating only
B. Sensible cooling and dehumidification
C. Humidification only
D. Adiabatic compression
Answer: B. Sensible cooling and dehumidification
Rationale: Cooling air below its dew-point temperature causes moisture
condensation while the dry-bulb temperature decreases.
, 5. For fully developed laminar flow through a circular pipe, the Darcy friction
factor is:
A. 16/Re
B. 32/Re
C. 64/Re
D. 0.316/Re^0.25
Answer: C. 64/Re
Rationale: For fully developed laminar flow in a circular pipe, the Darcy friction
factor is exactly 64 divided by the Reynolds number.
6. A steel pressure vessel has an internal diameter of 48 in. and wall thickness
of 0.50 in. If the internal pressure is 200 psi, the approximate hoop stress
using the thin-wall relation is:
A. 2,400 psi
B. 4,800 psi
C. 9,600 psi
D. 19,200 psi
Answer: C. 9,600 psi
Rationale: For a thin cylindrical vessel, hoop stress is σ = pD/(2t) =
(200)(48)/(2×0.50) = 9,600 psi.
7. A heat exchanger has a hot-fluid inlet temperature of 350°F and outlet
temperature of 250°F. The cold fluid enters at 100°F and leaves at 200°F.
For counterflow operation, the log mean temperature difference is:
A. 75°F
B. 100°F
C. 150°F
D. 200°F
Answer: C. 150°F
, Rationale: The terminal temperature differences are 350−200 = 150°F and
250−100 = 150°F. When both terminal differences are equal, the LMTD is 150°F.
8. Which nondimensional number compares inertial forces to viscous forces in
fluid flow?
A. Mach number
B. Reynolds number
C. Prandtl number
D. Froude number
Answer: B. Reynolds number
Rationale: Reynolds number represents the ratio of inertial forces to viscous
forces and is widely used to characterize laminar and turbulent flow.
9. In a closed hydronic heating system, an expansion tank is primarily installed
to:
A. Increase pump head
B. Remove dissolved oxygen
C. Accommodate thermal expansion of the water
D. Increase boiler efficiency
Answer: C. Accommodate thermal expansion of the water
Rationale: Water expands as its temperature increases. The expansion tank
provides a compressible volume that accommodates this expansion and limits
pressure fluctuations.
10.For a reciprocating internal-combustion engine, volumetric efficiency
primarily measures:
A. Ratio of actual inducted air to theoretical displacement volume
B. Mechanical friction losses
C. Fuel heating value
D. Brake power divided by indicated power
