Kansas Mechanical Engineer
Examination Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. Thermodynamics
A closed system undergoes a cycle in which the net heat transfer to the system is
420 kJ and the net work done by the system is 420 kJ. What is the net change in
internal energy over the cycle?
A. 420 kJ
B. -420 kJ
C. 840 kJ
D. 0 kJ
Answer: 0 kJ
,Rationale: For a complete thermodynamic cycle, the system returns to its initial
state. Because internal energy is a state function, its net change over the cycle is
zero.
2. Thermodynamics
An ideal gas is compressed isentropically from 100 kPa and 300 K to 800 kPa. For a
gas with k = 1.4, approximately what is the final temperature?
A. 386 K
B. 450 K
C. 543 K
D. 612 K
Answer: 543 K
Rationale: For an isentropic ideal-gas process, T₂/T₁ = (P₂/P₁)^*(k−1)/k+. Thus T₂ ≈
300(8)^0.2857 ≈ 543 K.
3. Thermodynamics
For a steady-flow turbine operating adiabatically with negligible changes in
elevation and velocity, the turbine work is primarily determined by:
A. The inlet pressure alone
B. The outlet pressure alone
C. The decrease in specific enthalpy
D. The increase in specific internal energy
Answer: The decrease in specific enthalpy
Rationale: The steady-flow energy equation reduces approximately to wₜ = h₁ −
h₂ for an adiabatic turbine with negligible kinetic and potential energy changes.
,4. Thermodynamics
A heat engine receives 1,200 kJ of heat from a high-temperature reservoir and
rejects 720 kJ to a low-temperature reservoir. What is its thermal efficiency?
A. 30%
B. 40%
C. 60%
D. 67%
Answer: 40%
Rationale: Thermal efficiency is η = (Qin − Qout)/Qin = (1,200 − 720)/1,200 =
0.40, or 40%.
5. Thermodynamics
Which condition most directly indicates that a two-phase water mixture is at
saturation equilibrium?
A. Temperature is greater than saturation temperature
B. Pressure is below saturation pressure
C. Temperature and pressure correspond to the saturation state
D. Specific volume equals the critical specific volume
Answer: Temperature and pressure correspond to the saturation state
Rationale: In a saturated two-phase mixture, pressure and temperature are
thermodynamically linked by the saturation relationship.
6. Thermodynamics
A refrigeration system has a refrigeration effect of 3.5 kW and requires 1.0 kW of
compressor power. What is its coefficient of performance?
, A. 0.286
B. 2.5
C. 3.5
D. 4.5
Answer: 3.5
Rationale: For a refrigerator, COP = refrigeration effect/work input = 3.5/1.0 =
3.5.
7. Thermodynamics
In an ideal Rankine cycle, superheating steam at constant boiler pressure
generally:
A. Reduces turbine work
B. Reduces the average temperature of heat addition
C. Increases turbine work and generally improves cycle efficiency
D. Eliminates condenser heat rejection
Answer: Increases turbine work and generally improves cycle efficiency
Rationale: Superheating increases the turbine inlet enthalpy and raises the
average temperature at which heat is supplied, generally increasing specific
turbine work and thermal efficiency.
8. Fluid Mechanics
Water flows through a horizontal pipe that decreases in diameter. If elevation
change and losses are negligible, what happens to static pressure as velocity
increases?
A. Static pressure increases
B. Static pressure remains constant
Examination Advanced 100-Question
Practice Exam 2026 | Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. Thermodynamics
A closed system undergoes a cycle in which the net heat transfer to the system is
420 kJ and the net work done by the system is 420 kJ. What is the net change in
internal energy over the cycle?
A. 420 kJ
B. -420 kJ
C. 840 kJ
D. 0 kJ
Answer: 0 kJ
,Rationale: For a complete thermodynamic cycle, the system returns to its initial
state. Because internal energy is a state function, its net change over the cycle is
zero.
2. Thermodynamics
An ideal gas is compressed isentropically from 100 kPa and 300 K to 800 kPa. For a
gas with k = 1.4, approximately what is the final temperature?
A. 386 K
B. 450 K
C. 543 K
D. 612 K
Answer: 543 K
Rationale: For an isentropic ideal-gas process, T₂/T₁ = (P₂/P₁)^*(k−1)/k+. Thus T₂ ≈
300(8)^0.2857 ≈ 543 K.
3. Thermodynamics
For a steady-flow turbine operating adiabatically with negligible changes in
elevation and velocity, the turbine work is primarily determined by:
A. The inlet pressure alone
B. The outlet pressure alone
C. The decrease in specific enthalpy
D. The increase in specific internal energy
Answer: The decrease in specific enthalpy
Rationale: The steady-flow energy equation reduces approximately to wₜ = h₁ −
h₂ for an adiabatic turbine with negligible kinetic and potential energy changes.
,4. Thermodynamics
A heat engine receives 1,200 kJ of heat from a high-temperature reservoir and
rejects 720 kJ to a low-temperature reservoir. What is its thermal efficiency?
A. 30%
B. 40%
C. 60%
D. 67%
Answer: 40%
Rationale: Thermal efficiency is η = (Qin − Qout)/Qin = (1,200 − 720)/1,200 =
0.40, or 40%.
5. Thermodynamics
Which condition most directly indicates that a two-phase water mixture is at
saturation equilibrium?
A. Temperature is greater than saturation temperature
B. Pressure is below saturation pressure
C. Temperature and pressure correspond to the saturation state
D. Specific volume equals the critical specific volume
Answer: Temperature and pressure correspond to the saturation state
Rationale: In a saturated two-phase mixture, pressure and temperature are
thermodynamically linked by the saturation relationship.
6. Thermodynamics
A refrigeration system has a refrigeration effect of 3.5 kW and requires 1.0 kW of
compressor power. What is its coefficient of performance?
, A. 0.286
B. 2.5
C. 3.5
D. 4.5
Answer: 3.5
Rationale: For a refrigerator, COP = refrigeration effect/work input = 3.5/1.0 =
3.5.
7. Thermodynamics
In an ideal Rankine cycle, superheating steam at constant boiler pressure
generally:
A. Reduces turbine work
B. Reduces the average temperature of heat addition
C. Increases turbine work and generally improves cycle efficiency
D. Eliminates condenser heat rejection
Answer: Increases turbine work and generally improves cycle efficiency
Rationale: Superheating increases the turbine inlet enthalpy and raises the
average temperature at which heat is supplied, generally increasing specific
turbine work and thermal efficiency.
8. Fluid Mechanics
Water flows through a horizontal pipe that decreases in diameter. If elevation
change and losses are negligible, what happens to static pressure as velocity
increases?
A. Static pressure increases
B. Static pressure remains constant
