NYC Electrician (CUNY) Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a circuit breaker?
A) To increase voltage
B) To store energy
C) To protect the circuit from overcurrent
D) To convert AC to DC
Rationale: Circuit breakers are designed to interrupt the flow of electricity
when current exceeds safe levels, preventing damage to the circuit.
2. According to the NEC, what is the maximum allowable voltage drop for
branch circuits?
A) 5%
, B) 8%
C) 3%
D) 10%
Rationale: The National Electrical Code recommends a maximum of 3%
voltage drop for branch circuits to ensure proper device operation and
efficiency.
3. What color is typically used for grounding conductors in the U.S.?
A) Red
B) White
C) Green
D) Black
Rationale: Green (or bare copper) is the standard color for grounding
conductors, ensuring safety and consistency.
4. Which of the following materials is most commonly used for
residential electrical wiring?
A) Aluminum
B) Steel
C) Copper
D) Silver
,Rationale: Copper has high conductivity, durability, and flexibility, making
it the standard for residential wiring.
5. What is the main function of a transformer?
A) To convert DC to AC
B) To store energy
C) To change voltage levels
D) To regulate current flow
Rationale: Transformers adjust voltage levels between circuits, either
stepping up or stepping down voltage as needed.
6. In a three-phase electrical system, what is the phase angle difference
between each phase?
A) 60°
B) 90°
C) 120°
D) 180°
Rationale: Three-phase systems have a 120° phase difference to provide
continuous power and balance the load.
7. What is the minimum wire size allowed for a 20-amp branch circuit
according to the NEC?
, A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
Rationale: 12 AWG copper wire is required for 20-amp circuits to safely
carry the current without overheating.
8. Which type of electrical motor is most commonly used in HVAC
systems?
A) Synchronous
B) Induction
C) Stepper
D) Servo
Rationale: Induction motors are durable, reliable, and efficient, making
them standard in HVAC applications.
9. What is the main advantage of using a GFCI (Ground Fault Circuit
Interrupter)?
A) Increases voltage
B) Reduces resistance
C) Protects against electrical shock
D) Converts AC to DC
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a circuit breaker?
A) To increase voltage
B) To store energy
C) To protect the circuit from overcurrent
D) To convert AC to DC
Rationale: Circuit breakers are designed to interrupt the flow of electricity
when current exceeds safe levels, preventing damage to the circuit.
2. According to the NEC, what is the maximum allowable voltage drop for
branch circuits?
A) 5%
, B) 8%
C) 3%
D) 10%
Rationale: The National Electrical Code recommends a maximum of 3%
voltage drop for branch circuits to ensure proper device operation and
efficiency.
3. What color is typically used for grounding conductors in the U.S.?
A) Red
B) White
C) Green
D) Black
Rationale: Green (or bare copper) is the standard color for grounding
conductors, ensuring safety and consistency.
4. Which of the following materials is most commonly used for
residential electrical wiring?
A) Aluminum
B) Steel
C) Copper
D) Silver
,Rationale: Copper has high conductivity, durability, and flexibility, making
it the standard for residential wiring.
5. What is the main function of a transformer?
A) To convert DC to AC
B) To store energy
C) To change voltage levels
D) To regulate current flow
Rationale: Transformers adjust voltage levels between circuits, either
stepping up or stepping down voltage as needed.
6. In a three-phase electrical system, what is the phase angle difference
between each phase?
A) 60°
B) 90°
C) 120°
D) 180°
Rationale: Three-phase systems have a 120° phase difference to provide
continuous power and balance the load.
7. What is the minimum wire size allowed for a 20-amp branch circuit
according to the NEC?
, A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
Rationale: 12 AWG copper wire is required for 20-amp circuits to safely
carry the current without overheating.
8. Which type of electrical motor is most commonly used in HVAC
systems?
A) Synchronous
B) Induction
C) Stepper
D) Servo
Rationale: Induction motors are durable, reliable, and efficient, making
them standard in HVAC applications.
9. What is the main advantage of using a GFCI (Ground Fault Circuit
Interrupter)?
A) Increases voltage
B) Reduces resistance
C) Protects against electrical shock
D) Converts AC to DC
