NYC Master Electrician Written Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.A 120/240-volt single-phase dwelling service has a calculated load of 165
amperes. In accordance with standard service sizing principles used in the
NYC Electrical Code and NEC requirements, which of the following service
disconnect ratings would be the minimum acceptable standard rating for this
installation?
A. 150 amperes
B. 200 amperes
C. 175 amperes
D. 180 amperes
Rationale: Service equipment must be sized not less than the calculated
load, and standard overcurrent device ratings are used. Since 165 amperes
exceeds 150 amperes, a 200-ampere service is the next standard size that
complies with code requirements.
, 2. Which of the following best describes the primary purpose of
equipment grounding conductors in an electrical system?
A. To carry normal load current
B. To stabilize utility voltage fluctuations
C. To provide a low-impedance path for fault current
D. To increase branch-circuit ampacity
Rationale: Equipment grounding conductors are intended to facilitate the
operation of overcurrent protective devices by providing a low-impedance
fault-current path during ground-fault conditions.
3. A feeder supplies continuous lighting loads totaling 80 amperes. What
is the minimum ampacity required for the feeder conductors?
A. 80 amperes
B. 90 amperes
C. 95 amperes
D. 100 amperes
Rationale: Continuous loads must generally be calculated at 125 percent.
Multiplying 80 amperes by 125 percent results in a required feeder
ampacity of 100 amperes.
4. What is the principal purpose of bonding metal raceways and
enclosures together?
,A. To reduce conductor voltage drop
B. To improve power factor
C. To establish electrical continuity and fault-current paths
D. To increase conductor insulation life
Rationale: Bonding ensures all conductive parts remain at substantially the
same potential and provides an effective path for fault current.
5. In a branch circuit supplying receptacle outlets in a dwelling-unit
kitchen, GFCI protection is primarily intended to protect against:
A. Overloads
B. Short circuits
C. Arc faults only
D. Electric shock hazards from ground faults
Rationale: Ground-fault circuit interrupters detect imbalance between
ungrounded and grounded conductors and quickly disconnect power to
reduce shock hazards.
6. Which conductor is intentionally connected to ground at the service
disconnecting means?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Grounded conductor (neutral)
D. Bonding jumper only
, Rationale: The grounded conductor is bonded to the grounding electrode
system at the service equipment to establish a reference to earth and
facilitate fault clearing.
7. When determining conductor ampacity, which factor is most likely to
require ampacity adjustment?
A. Color of insulation
B. Manufacturer’s warranty period
C. Length of conduit only
D. Current-carrying conductors installed together in a raceway
Rationale: Multiple current-carrying conductors in the same raceway can
increase heat buildup and require ampacity adjustment factors.
8. Which wiring method provides mechanical protection and serves as an
equipment grounding path when properly installed?
A. Flexible cord
B. Nonmetallic tubing
C. Rigid metal conduit
D. Open conductors on insulators
Rationale: Rigid metal conduit offers substantial physical protection and
can function as an effective equipment grounding conductor when properly
connected.
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.A 120/240-volt single-phase dwelling service has a calculated load of 165
amperes. In accordance with standard service sizing principles used in the
NYC Electrical Code and NEC requirements, which of the following service
disconnect ratings would be the minimum acceptable standard rating for this
installation?
A. 150 amperes
B. 200 amperes
C. 175 amperes
D. 180 amperes
Rationale: Service equipment must be sized not less than the calculated
load, and standard overcurrent device ratings are used. Since 165 amperes
exceeds 150 amperes, a 200-ampere service is the next standard size that
complies with code requirements.
, 2. Which of the following best describes the primary purpose of
equipment grounding conductors in an electrical system?
A. To carry normal load current
B. To stabilize utility voltage fluctuations
C. To provide a low-impedance path for fault current
D. To increase branch-circuit ampacity
Rationale: Equipment grounding conductors are intended to facilitate the
operation of overcurrent protective devices by providing a low-impedance
fault-current path during ground-fault conditions.
3. A feeder supplies continuous lighting loads totaling 80 amperes. What
is the minimum ampacity required for the feeder conductors?
A. 80 amperes
B. 90 amperes
C. 95 amperes
D. 100 amperes
Rationale: Continuous loads must generally be calculated at 125 percent.
Multiplying 80 amperes by 125 percent results in a required feeder
ampacity of 100 amperes.
4. What is the principal purpose of bonding metal raceways and
enclosures together?
,A. To reduce conductor voltage drop
B. To improve power factor
C. To establish electrical continuity and fault-current paths
D. To increase conductor insulation life
Rationale: Bonding ensures all conductive parts remain at substantially the
same potential and provides an effective path for fault current.
5. In a branch circuit supplying receptacle outlets in a dwelling-unit
kitchen, GFCI protection is primarily intended to protect against:
A. Overloads
B. Short circuits
C. Arc faults only
D. Electric shock hazards from ground faults
Rationale: Ground-fault circuit interrupters detect imbalance between
ungrounded and grounded conductors and quickly disconnect power to
reduce shock hazards.
6. Which conductor is intentionally connected to ground at the service
disconnecting means?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Grounded conductor (neutral)
D. Bonding jumper only
, Rationale: The grounded conductor is bonded to the grounding electrode
system at the service equipment to establish a reference to earth and
facilitate fault clearing.
7. When determining conductor ampacity, which factor is most likely to
require ampacity adjustment?
A. Color of insulation
B. Manufacturer’s warranty period
C. Length of conduit only
D. Current-carrying conductors installed together in a raceway
Rationale: Multiple current-carrying conductors in the same raceway can
increase heat buildup and require ampacity adjustment factors.
8. Which wiring method provides mechanical protection and serves as an
equipment grounding path when properly installed?
A. Flexible cord
B. Nonmetallic tubing
C. Rigid metal conduit
D. Open conductors on insulators
Rationale: Rigid metal conduit offers substantial physical protection and
can function as an effective equipment grounding conductor when properly
connected.
