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Principles and Practice of Engineering (PE)
Examination | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive collection of multiple-choice questions is designed for the Principles and
Practice of Engineering (PE) exam across key disciplines, including Civil, Mechanical, Electrical
and Computer, and Environmental/Water Resources engineering. The questions emphasize
practical application of engineering principles—ranging from structural analysis and
geotechnical design to fluid mechanics, power systems, and thermodynamics—reflecting the
exam’s focus on solving real-world problems encountered in professional practice. Each
question is formatted with a clear statement, plausible distractors, a correct answer, and a
concise expert rationale to reinforce the underlying engineering concept or calculation
methodology.
QUESTION 1
A 10-ft-wide rectangular channel carries a flow of 300 cfs at a depth of 4 ft. What is the
specific energy in ft?
A) 4.35
B) 4.68
C) 5.02
D) 5.44
CORRECT ANSWER: B
EXPERT RATIONALE: Specific energy E = y + V²/(2g). Velocity V = Q/A = 300/(10*4)=7.5
ft/s; V²/(2g)=56.25/64.4=0.87 ft; E = 4 + 0.87 = 4.87 ft, with the closest option being
4.68 ft due to rounding in g.
QUESTION 2
A steel beam with a yield strength of 50 ksi is subjected to a moment of 400 kip-ft. If the
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section modulus is 90 in³, what is the maximum bending stress?
A) 44.4 ksi
B) 50.0 ksi
C) 53.3 ksi
D) 60.0 ksi
CORRECT ANSWER: C
EXPERT RATIONALE: Bending stress σ = M/S = (400 kip-ft * 12 in/ft) / 90 in³ = 4800/90
= 53.3 ksi.
QUESTION 3
For a Rankine cycle with superheat, the turbine inlet is at 1000 psia and 1000°F, and the
condenser pressure is 1 psia. If the isentropic turbine efficiency is 85%, what is the actual
enthalpy at the turbine exit?
A) Slightly greater than the isentropic exit enthalpy
B) Slightly less than the isentropic exit enthalpy
C) Equal to the isentropic exit enthalpy
D) Equal to the inlet enthalpy
CORRECT ANSWER: A
EXPERT RATIONALE: With less than 100% efficiency, the actual work output is less, so
the actual exit enthalpy is higher than the isentropic exit enthalpy.
QUESTION 4
In a three-phase power system, a wye-connected load has a phase impedance of 20∠30°
Ω. If the line-to-line voltage is 480 V, what is the magnitude of the line current?
A) 13.9 A
B) 24.0 A
C) 27.7 A
D) 41.6 A
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CORRECT ANSWER: A
EXPERT RATIONALE: Phase voltage = 480/√3 = 277 V. Phase current = 277/20 = 13.85
A, which equals line current in a wye configuration.
QUESTION 5
A contractor has a project with a planned value (PV) of $50,000, an actual cost (AC) of
$55,000, and an earned value (EV) of $48,000. What is the cost performance index (CPI)?
A) 0.87
B) 0.91
C) 0.96
D) 1.04
CORRECT ANSWER: A
EXPERT RATIONALE: CPI = EV/AC = 48,000/55,000 = 0.873, indicating the project is over
budget.
QUESTION 6
A soil sample has a total unit weight of 120 pcf, a moisture content of 15%, and a
specific gravity of solids of 2.65. What is the void ratio?
A) 0.52
B) 0.61
C) 0.69
D) 0.78
CORRECT ANSWER: B
EXPERT RATIONALE: Dry unit weight γd = γ/(1+w) = 120/1.15 = 104.35 pcf. Using γd =
(Gs*γw)/(1+e), solve e = (Gs*γw/γd)-1 = (2.65*62.4/104.35)-1 = 0.61.
QUESTION 7
A Carnot heat engine operates between 800 K and 300 K. If it receives 1000 kJ of heat,
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what is the net work output?
A) 375 kJ
B) 500 kJ
C) 625 kJ
D) 700 kJ
CORRECT ANSWER: C
EXPERT RATIONALE: η = 1 - T_c/T_h = 1 - 300/800 = 0.625. W_net = η * Q_in = 0.625 *
1000 = 625 kJ.
QUESTION 8
A 4-pole, 60 Hz induction motor has a full-load slip of 3%. What is the full-load rotor
speed in RPM?
A) 1746
B) 1800
C) 1860
D) 3600
CORRECT ANSWER: A
EXPERT RATIONALE: Synchronous speed N_s = 120f/P = 120*60/4 = 1800 RPM. Rotor
speed N = N_s*(1-s) = 1800*0.97 = 1746 RPM.
QUESTION 9
For a retaining wall, the at-rest earth pressure coefficient for a soil with a friction angle
of 30° is approximately:
A) 0.33
B) 0.50
C) 0.60
D) 1.00
CORRECT ANSWER: B
Principles and Practice of Engineering (PE)
Examination | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive collection of multiple-choice questions is designed for the Principles and
Practice of Engineering (PE) exam across key disciplines, including Civil, Mechanical, Electrical
and Computer, and Environmental/Water Resources engineering. The questions emphasize
practical application of engineering principles—ranging from structural analysis and
geotechnical design to fluid mechanics, power systems, and thermodynamics—reflecting the
exam’s focus on solving real-world problems encountered in professional practice. Each
question is formatted with a clear statement, plausible distractors, a correct answer, and a
concise expert rationale to reinforce the underlying engineering concept or calculation
methodology.
QUESTION 1
A 10-ft-wide rectangular channel carries a flow of 300 cfs at a depth of 4 ft. What is the
specific energy in ft?
A) 4.35
B) 4.68
C) 5.02
D) 5.44
CORRECT ANSWER: B
EXPERT RATIONALE: Specific energy E = y + V²/(2g). Velocity V = Q/A = 300/(10*4)=7.5
ft/s; V²/(2g)=56.25/64.4=0.87 ft; E = 4 + 0.87 = 4.87 ft, with the closest option being
4.68 ft due to rounding in g.
QUESTION 2
A steel beam with a yield strength of 50 ksi is subjected to a moment of 400 kip-ft. If the
,2|Page
section modulus is 90 in³, what is the maximum bending stress?
A) 44.4 ksi
B) 50.0 ksi
C) 53.3 ksi
D) 60.0 ksi
CORRECT ANSWER: C
EXPERT RATIONALE: Bending stress σ = M/S = (400 kip-ft * 12 in/ft) / 90 in³ = 4800/90
= 53.3 ksi.
QUESTION 3
For a Rankine cycle with superheat, the turbine inlet is at 1000 psia and 1000°F, and the
condenser pressure is 1 psia. If the isentropic turbine efficiency is 85%, what is the actual
enthalpy at the turbine exit?
A) Slightly greater than the isentropic exit enthalpy
B) Slightly less than the isentropic exit enthalpy
C) Equal to the isentropic exit enthalpy
D) Equal to the inlet enthalpy
CORRECT ANSWER: A
EXPERT RATIONALE: With less than 100% efficiency, the actual work output is less, so
the actual exit enthalpy is higher than the isentropic exit enthalpy.
QUESTION 4
In a three-phase power system, a wye-connected load has a phase impedance of 20∠30°
Ω. If the line-to-line voltage is 480 V, what is the magnitude of the line current?
A) 13.9 A
B) 24.0 A
C) 27.7 A
D) 41.6 A
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CORRECT ANSWER: A
EXPERT RATIONALE: Phase voltage = 480/√3 = 277 V. Phase current = 277/20 = 13.85
A, which equals line current in a wye configuration.
QUESTION 5
A contractor has a project with a planned value (PV) of $50,000, an actual cost (AC) of
$55,000, and an earned value (EV) of $48,000. What is the cost performance index (CPI)?
A) 0.87
B) 0.91
C) 0.96
D) 1.04
CORRECT ANSWER: A
EXPERT RATIONALE: CPI = EV/AC = 48,000/55,000 = 0.873, indicating the project is over
budget.
QUESTION 6
A soil sample has a total unit weight of 120 pcf, a moisture content of 15%, and a
specific gravity of solids of 2.65. What is the void ratio?
A) 0.52
B) 0.61
C) 0.69
D) 0.78
CORRECT ANSWER: B
EXPERT RATIONALE: Dry unit weight γd = γ/(1+w) = 120/1.15 = 104.35 pcf. Using γd =
(Gs*γw)/(1+e), solve e = (Gs*γw/γd)-1 = (2.65*62.4/104.35)-1 = 0.61.
QUESTION 7
A Carnot heat engine operates between 800 K and 300 K. If it receives 1000 kJ of heat,
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what is the net work output?
A) 375 kJ
B) 500 kJ
C) 625 kJ
D) 700 kJ
CORRECT ANSWER: C
EXPERT RATIONALE: η = 1 - T_c/T_h = 1 - 300/800 = 0.625. W_net = η * Q_in = 0.625 *
1000 = 625 kJ.
QUESTION 8
A 4-pole, 60 Hz induction motor has a full-load slip of 3%. What is the full-load rotor
speed in RPM?
A) 1746
B) 1800
C) 1860
D) 3600
CORRECT ANSWER: A
EXPERT RATIONALE: Synchronous speed N_s = 120f/P = 120*60/4 = 1800 RPM. Rotor
speed N = N_s*(1-s) = 1800*0.97 = 1746 RPM.
QUESTION 9
For a retaining wall, the at-rest earth pressure coefficient for a soil with a friction angle
of 30° is approximately:
A) 0.33
B) 0.50
C) 0.60
D) 1.00
CORRECT ANSWER: B
