Principles and Practice of Engineering (PE) Electrical and
Computer Examination Questions And Correct Answers
(Verified Answers) Plus Rationales 2025/2026 Q&A | Instant
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1. Which of the following is the primary purpose of a transformer in an AC
power system?
A) Store electrical energy
B) Convert AC to DC
C) Step up or step down voltage
D) Measure current
Answer: C) Step up or step down voltage
Transformers are used to change the voltage level in AC systems, either
increasing (step-up) or decreasing (step-down) voltage, while maintaining
power.
2. For a three-phase, balanced, wye-connected load, the line-to-line voltage
𝑽𝑳 is related to the line-to-neutral voltage 𝑽𝑳𝑵 as:
A) 𝑉𝐿 = 𝑉𝐿𝑁
B) 𝑉𝐿 = √2𝑉𝐿𝑁
C) 𝑉𝐿 = √3𝑉𝐿𝑁
D) 𝑉𝐿 = 3𝑉𝐿𝑁
Answer: C) 𝑉𝐿 = √3𝑉𝐿𝑁
In a wye connection, the line-to-line voltage is √3 times the phase (line-to-
neutral) voltage.
3. What is the main advantage of using a synchronous motor in industry?
A) High starting torque
B) Constant speed under varying load
C) Simple construction
D) Self-starting
,Answer: B) Constant speed under varying load
Synchronous motors operate at a fixed speed determined by supply frequency
and number of poles, regardless of load, making them ideal for precision
applications.
4. In digital logic, what is the function of a flip-flop?
A) Amplify signals
B) Store a single bit of information
C) Convert analog to digital signals
D) Generate clock signals
Answer: B) Store a single bit of information
Flip-flops are bistable devices used to store one bit of data, fundamental in
sequential digital circuits.
5. According to Ohm’s Law, the current 𝑰through a resistor is given by:
A) 𝐼 = 𝑉 ⋅ 𝑅
B) 𝐼 = 𝑉/𝑅
C) 𝐼 = 𝑅/𝑉
D) 𝐼 = 𝑉 2 /𝑅
Answer: B) I = V / R
Ohm’s Law states that current is directly proportional to voltage and inversely
proportional to resistance.
6. The per-unit system is commonly used in power systems analysis because
it:
A) Reduces the number of calculations
B) Normalizes quantities relative to system ratings
C) Eliminates the need for transformers
D) Simplifies AC to DC conversion
Answer: B) Normalizes quantities relative to system ratings
The per-unit system expresses voltages, currents, and impedances as fractions
of a base value, simplifying comparisons and calculations.
, 7. A digital signal is defined by:
A) Continuous amplitude
B) Discrete levels
C) Frequency only
D) Phase angle only
Answer: B) Discrete levels
Digital signals have specific levels representing binary data, unlike analog
signals which vary continuously.
8. Which law is used to analyze the voltage around a closed loop in an
electrical circuit?
A) Ohm’s Law
B) Kirchhoff’s Voltage Law (KVL)
C) Kirchhoff’s Current Law (KCL)
D) Faraday’s Law
Answer: B) Kirchhoff’s Voltage Law (KVL)
KVL states that the sum of all voltages around a closed loop equals zero.
9. A stepper motor is preferred in applications where:
A) High torque is required at all speeds
B) Precise angular positioning is required
C) Constant speed operation is critical
D) Variable frequency drives are not available
Answer: B) Precise angular positioning is required
Stepper motors move in discrete steps, making them ideal for accurate position
control in robotics and CNC machines.
10. In a single-phase AC circuit with a resistive load, the voltage and current
are:
Computer Examination Questions And Correct Answers
(Verified Answers) Plus Rationales 2025/2026 Q&A | Instant
Download Pdf
1. Which of the following is the primary purpose of a transformer in an AC
power system?
A) Store electrical energy
B) Convert AC to DC
C) Step up or step down voltage
D) Measure current
Answer: C) Step up or step down voltage
Transformers are used to change the voltage level in AC systems, either
increasing (step-up) or decreasing (step-down) voltage, while maintaining
power.
2. For a three-phase, balanced, wye-connected load, the line-to-line voltage
𝑽𝑳 is related to the line-to-neutral voltage 𝑽𝑳𝑵 as:
A) 𝑉𝐿 = 𝑉𝐿𝑁
B) 𝑉𝐿 = √2𝑉𝐿𝑁
C) 𝑉𝐿 = √3𝑉𝐿𝑁
D) 𝑉𝐿 = 3𝑉𝐿𝑁
Answer: C) 𝑉𝐿 = √3𝑉𝐿𝑁
In a wye connection, the line-to-line voltage is √3 times the phase (line-to-
neutral) voltage.
3. What is the main advantage of using a synchronous motor in industry?
A) High starting torque
B) Constant speed under varying load
C) Simple construction
D) Self-starting
,Answer: B) Constant speed under varying load
Synchronous motors operate at a fixed speed determined by supply frequency
and number of poles, regardless of load, making them ideal for precision
applications.
4. In digital logic, what is the function of a flip-flop?
A) Amplify signals
B) Store a single bit of information
C) Convert analog to digital signals
D) Generate clock signals
Answer: B) Store a single bit of information
Flip-flops are bistable devices used to store one bit of data, fundamental in
sequential digital circuits.
5. According to Ohm’s Law, the current 𝑰through a resistor is given by:
A) 𝐼 = 𝑉 ⋅ 𝑅
B) 𝐼 = 𝑉/𝑅
C) 𝐼 = 𝑅/𝑉
D) 𝐼 = 𝑉 2 /𝑅
Answer: B) I = V / R
Ohm’s Law states that current is directly proportional to voltage and inversely
proportional to resistance.
6. The per-unit system is commonly used in power systems analysis because
it:
A) Reduces the number of calculations
B) Normalizes quantities relative to system ratings
C) Eliminates the need for transformers
D) Simplifies AC to DC conversion
Answer: B) Normalizes quantities relative to system ratings
The per-unit system expresses voltages, currents, and impedances as fractions
of a base value, simplifying comparisons and calculations.
, 7. A digital signal is defined by:
A) Continuous amplitude
B) Discrete levels
C) Frequency only
D) Phase angle only
Answer: B) Discrete levels
Digital signals have specific levels representing binary data, unlike analog
signals which vary continuously.
8. Which law is used to analyze the voltage around a closed loop in an
electrical circuit?
A) Ohm’s Law
B) Kirchhoff’s Voltage Law (KVL)
C) Kirchhoff’s Current Law (KCL)
D) Faraday’s Law
Answer: B) Kirchhoff’s Voltage Law (KVL)
KVL states that the sum of all voltages around a closed loop equals zero.
9. A stepper motor is preferred in applications where:
A) High torque is required at all speeds
B) Precise angular positioning is required
C) Constant speed operation is critical
D) Variable frequency drives are not available
Answer: B) Precise angular positioning is required
Stepper motors move in discrete steps, making them ideal for accurate position
control in robotics and CNC machines.
10. In a single-phase AC circuit with a resistive load, the voltage and current
are:
