NYC Electrician (Prom) Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the standard voltage for most residential circuits in the United
States?
A) 120 V
B) 208 V
C) 240 V
D) 480 V
Rationale: Residential circuits typically use 120/240 V split-phase, with
240 V used for larger appliances like ovens and dryers.
2. According to the National Electrical Code (NEC), the minimum size
grounding electrode conductor for a 200-amp service is:
A) 6 AWG
, B) 4 AWG
C) 2 AWG
D) 1/0 AWG
Rationale: NEC Table 250.66 specifies 4 AWG copper for a 200-amp
service when using a ground rod.
3. What is the primary purpose of a GFCI (Ground Fault Circuit
Interrupter)?
A) Prevent short circuits
B) Prevent electrical shock
C) Increase voltage
D) Protect equipment from surges
Rationale: GFCIs trip when there is a difference in current between hot
and neutral, protecting people from electric shock.
4. In NYC, which of the following requires a permit before electrical work
can begin?
A) Replacing a light bulb
B) Installing a new lamp
C) Adding a new circuit to a building
D) Plugging in a surge protector
Rationale: Any significant wiring change, including new circuits,
requires a permit according to NYC Electrical Code.
,5. What type of conduit is commonly used for exposed interior wiring in
commercial buildings?
A) EMT (Electrical Metallic Tubing)
B) PVC
C) UF cable
D) Knob and tube
Rationale: PVC is widely used for exposed interior commercial wiring
due to its durability and insulation properties.
6. What color is typically used for the neutral conductor in electrical
wiring?
A) Black
B) Red
C) White
D) Green
Rationale: NEC specifies that white or gray conductors are used as
neutral.
7. What is the maximum allowable voltage drop for branch circuits in a
commercial building?
A) 1%
, B) 2%
C) 3%
D) 5%
Rationale: NEC recommends a maximum voltage drop of 3% for
branch circuits to ensure proper equipment operation.
8. Which device is designed to protect wiring from overheating due to
excessive current?
A) Transformer
B) Circuit breaker
C) GFCI
D) Contactor
Rationale: Circuit breakers and fuses protect conductors from
overcurrent, preventing fires and damage.
9. In NYC, what is the minimum clearance above a residential swimming
pool for overhead electrical conductors?
A) 8 feet
B) 10 feet
C) 15 feet
D) 22.5 feet
Rationale: NEC 680.8 specifies a minimum of 22.5 feet to prevent
electrical hazards over pools.
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the standard voltage for most residential circuits in the United
States?
A) 120 V
B) 208 V
C) 240 V
D) 480 V
Rationale: Residential circuits typically use 120/240 V split-phase, with
240 V used for larger appliances like ovens and dryers.
2. According to the National Electrical Code (NEC), the minimum size
grounding electrode conductor for a 200-amp service is:
A) 6 AWG
, B) 4 AWG
C) 2 AWG
D) 1/0 AWG
Rationale: NEC Table 250.66 specifies 4 AWG copper for a 200-amp
service when using a ground rod.
3. What is the primary purpose of a GFCI (Ground Fault Circuit
Interrupter)?
A) Prevent short circuits
B) Prevent electrical shock
C) Increase voltage
D) Protect equipment from surges
Rationale: GFCIs trip when there is a difference in current between hot
and neutral, protecting people from electric shock.
4. In NYC, which of the following requires a permit before electrical work
can begin?
A) Replacing a light bulb
B) Installing a new lamp
C) Adding a new circuit to a building
D) Plugging in a surge protector
Rationale: Any significant wiring change, including new circuits,
requires a permit according to NYC Electrical Code.
,5. What type of conduit is commonly used for exposed interior wiring in
commercial buildings?
A) EMT (Electrical Metallic Tubing)
B) PVC
C) UF cable
D) Knob and tube
Rationale: PVC is widely used for exposed interior commercial wiring
due to its durability and insulation properties.
6. What color is typically used for the neutral conductor in electrical
wiring?
A) Black
B) Red
C) White
D) Green
Rationale: NEC specifies that white or gray conductors are used as
neutral.
7. What is the maximum allowable voltage drop for branch circuits in a
commercial building?
A) 1%
, B) 2%
C) 3%
D) 5%
Rationale: NEC recommends a maximum voltage drop of 3% for
branch circuits to ensure proper equipment operation.
8. Which device is designed to protect wiring from overheating due to
excessive current?
A) Transformer
B) Circuit breaker
C) GFCI
D) Contactor
Rationale: Circuit breakers and fuses protect conductors from
overcurrent, preventing fires and damage.
9. In NYC, what is the minimum clearance above a residential swimming
pool for overhead electrical conductors?
A) 8 feet
B) 10 feet
C) 15 feet
D) 22.5 feet
Rationale: NEC 680.8 specifies a minimum of 22.5 feet to prevent
electrical hazards over pools.
