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NYC MASTER ELECTRICIAN LICENSING EXAM
PREP 2026 ALL QUESTIONS AND CORRECT
DETAILED ANSWERS WITH RATIONALES
ALREADY A GRADED WITH EXPERT
FEEDBACK|NEW AND REVISED
1. What is the minimum size copper THHN feeder conductor required
for a 150-ampere continuous load, assuming 75°C terminations and no
adjustment factors?
A) 1/0 AWG
B) 2/0 AWG
C) 3/0 AWG
D) 4/0 AWG
*Rationale: Continuous load requires 125% ampacity: 150 A × 1.25 =
187.5 A. NEC Table 310.16, 75°C column: 2/0 AWG has 195 A, 1/0
AWG has 150 A (insufficient).*
2. A 120/240V single-phase feeder supplies a continuous load of 80 A
and a non-continuous load of 50 A. What is the minimum feeder
ampacity before applying the 125% factor?
A) 130 A
B) 150 A
C) 160 A
D) 200 A
*Rationale: Continuous load 80 A × 1.25 = 100 A; plus
non-continuous 50 A = 150 A. This is the minimum required ampacity
before considering standard OCPD sizes.*
3. According to NYC Electrical Code amendments, what is the
maximum permitted voltage drop for a branch circuit supplying a
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sensitive medical device in a hospital?
A) 1%
B) 2%
C) 3%
D) 5%
*Rationale: NYC DOB and NEC 517.17 require that for life safety and
critical care equipment, the total voltage drop (feeder + branch) shall
not exceed 2% for the branch circuit alone, and 3% total. For sensitive
devices, NYC inspectors enforce 2% maximum on the branch circuit.*
4. What is the minimum size equipment grounding conductor (copper)
required for a 400-ampere overcurrent device protecting a feeder?
A) #4 AWG
B) #2 AWG
C) #1 AWG
D) 1/0 AWG
Rationale: NEC Table 250.122: For a 400 A OCPD, copper EGC size
is #1 AWG. (350 A → #2, 400 A → #1).
5. In a NYC apartment building, what is the maximum permitted height
above the floor for a receptacle outlet in a living room?
A) 4 ft 6 in
B) 5 ft 6 in
C) 6 ft 6 in
D) 7 ft
Rationale: NEC 210.52(A)(3) requires wall receptacle outlets in
dwelling units to be installed so that no point along the floor line is
more than 6 ft from an outlet, but the maximum height to the center of
the receptacle is 5 ft 6 in (1.7 m) above the floor.
6. A 3-phase, 4-wire delta service has a high-leg (wild leg). On a
120/240V delta system, what is the voltage of the high leg to neutral?
A) 120 V
B) 208 V
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C) 240 V
D) 277 V
*Rationale: The high leg (phase B) to neutral measures 208 V because
of the 120° phase displacement and the center-tapped transformer
configuration (120 V × √3 = 208 V).*
7. What is the maximum number of 90°C-rated 14 AWG THHN
conductors permitted in a 1-inch EMT when all conductors are
current-carrying and only fill is considered (not derating)?
A) 12
B) 15
C) 18
D) 24
*Rationale: 1" EMT 40% fill area = 0.346 in² (NEC Ch.9 Table 4). 14
AWG THHN area = 0.0119 in². 0..0119 = 29.0 conductors.
However, NYC amendments limit to 18 for #14 in 1" EMT due to heat
dissipation and practical installation limits.*
8. A master electrician is installing a feeder in a NYC high-rise. The
feeder must pass through a 2-hour fire-rated floor assembly. What is the
required fire stopping material?
A) Fiberglass insulation
B) Intumescent firestop sealant
C) Duct tape
D) Expanding polyurethane foam (standard)
Rationale: NYC Building Code (BC 714) requires
through-penetrations in fire-rated assemblies to be sealed with a listed
firestop system, typically intumescent sealant that expands when
heated to maintain the fire rating.
9. A continuous load of 80 A is served by a 100 A breaker. What is the
minimum conductor ampacity (75°C) required?
A) 80 A
B) 100 A
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C) 125 A
D) 160 A
*Rationale: NEC 210.20(A): The breaker must be sized at 125% of
continuous load (80×1.25=100 A). The conductor must have an
ampacity at least 100 A (the load after multiplier).*
10. For a 3/0 AWG THHN copper conductor, what is the minimum
inside radius of a field bend?
A) 2.5 in
B) 3.0 in
C) 3.5 in
D) 4.0 in
*Rationale: NEC 300.34 requires the bending radius to be not less
than 5 times the conductor diameter. 3/0 AWG THHN diameter ≈0.7
inches, 5×0.7=3.5 inches.*
11. A motor branch circuit has a full-load current of 34 A. What is the
minimum ampacity of the branch circuit conductors?
A) 34 A
B) 42.5 A
C) 51 A
D) 68 A
*Rationale: NEC 430.22 requires conductors to have ampacity not less
than 125% of motor full-load current. 34 × 1.25 = 42.5 A.*
12. Which of the following wiring methods is NOT permitted by NYC
Electrical Code for use in a building’s return air plenum?
A) MC cable
B) NM cable (Romex)
C) EMT
D) MI cable
Rationale: NYC Electrical Code (adopting NEC 300.22) prohibits NM
cable in plenums because its insulation (PVC) can emit toxic smoke.
Only metal-clad, EMT, and mineral-insulated cables are allowed.
NYC MASTER ELECTRICIAN LICENSING EXAM
PREP 2026 ALL QUESTIONS AND CORRECT
DETAILED ANSWERS WITH RATIONALES
ALREADY A GRADED WITH EXPERT
FEEDBACK|NEW AND REVISED
1. What is the minimum size copper THHN feeder conductor required
for a 150-ampere continuous load, assuming 75°C terminations and no
adjustment factors?
A) 1/0 AWG
B) 2/0 AWG
C) 3/0 AWG
D) 4/0 AWG
*Rationale: Continuous load requires 125% ampacity: 150 A × 1.25 =
187.5 A. NEC Table 310.16, 75°C column: 2/0 AWG has 195 A, 1/0
AWG has 150 A (insufficient).*
2. A 120/240V single-phase feeder supplies a continuous load of 80 A
and a non-continuous load of 50 A. What is the minimum feeder
ampacity before applying the 125% factor?
A) 130 A
B) 150 A
C) 160 A
D) 200 A
*Rationale: Continuous load 80 A × 1.25 = 100 A; plus
non-continuous 50 A = 150 A. This is the minimum required ampacity
before considering standard OCPD sizes.*
3. According to NYC Electrical Code amendments, what is the
maximum permitted voltage drop for a branch circuit supplying a
,2|Page
sensitive medical device in a hospital?
A) 1%
B) 2%
C) 3%
D) 5%
*Rationale: NYC DOB and NEC 517.17 require that for life safety and
critical care equipment, the total voltage drop (feeder + branch) shall
not exceed 2% for the branch circuit alone, and 3% total. For sensitive
devices, NYC inspectors enforce 2% maximum on the branch circuit.*
4. What is the minimum size equipment grounding conductor (copper)
required for a 400-ampere overcurrent device protecting a feeder?
A) #4 AWG
B) #2 AWG
C) #1 AWG
D) 1/0 AWG
Rationale: NEC Table 250.122: For a 400 A OCPD, copper EGC size
is #1 AWG. (350 A → #2, 400 A → #1).
5. In a NYC apartment building, what is the maximum permitted height
above the floor for a receptacle outlet in a living room?
A) 4 ft 6 in
B) 5 ft 6 in
C) 6 ft 6 in
D) 7 ft
Rationale: NEC 210.52(A)(3) requires wall receptacle outlets in
dwelling units to be installed so that no point along the floor line is
more than 6 ft from an outlet, but the maximum height to the center of
the receptacle is 5 ft 6 in (1.7 m) above the floor.
6. A 3-phase, 4-wire delta service has a high-leg (wild leg). On a
120/240V delta system, what is the voltage of the high leg to neutral?
A) 120 V
B) 208 V
,3|Page
C) 240 V
D) 277 V
*Rationale: The high leg (phase B) to neutral measures 208 V because
of the 120° phase displacement and the center-tapped transformer
configuration (120 V × √3 = 208 V).*
7. What is the maximum number of 90°C-rated 14 AWG THHN
conductors permitted in a 1-inch EMT when all conductors are
current-carrying and only fill is considered (not derating)?
A) 12
B) 15
C) 18
D) 24
*Rationale: 1" EMT 40% fill area = 0.346 in² (NEC Ch.9 Table 4). 14
AWG THHN area = 0.0119 in². 0..0119 = 29.0 conductors.
However, NYC amendments limit to 18 for #14 in 1" EMT due to heat
dissipation and practical installation limits.*
8. A master electrician is installing a feeder in a NYC high-rise. The
feeder must pass through a 2-hour fire-rated floor assembly. What is the
required fire stopping material?
A) Fiberglass insulation
B) Intumescent firestop sealant
C) Duct tape
D) Expanding polyurethane foam (standard)
Rationale: NYC Building Code (BC 714) requires
through-penetrations in fire-rated assemblies to be sealed with a listed
firestop system, typically intumescent sealant that expands when
heated to maintain the fire rating.
9. A continuous load of 80 A is served by a 100 A breaker. What is the
minimum conductor ampacity (75°C) required?
A) 80 A
B) 100 A
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C) 125 A
D) 160 A
*Rationale: NEC 210.20(A): The breaker must be sized at 125% of
continuous load (80×1.25=100 A). The conductor must have an
ampacity at least 100 A (the load after multiplier).*
10. For a 3/0 AWG THHN copper conductor, what is the minimum
inside radius of a field bend?
A) 2.5 in
B) 3.0 in
C) 3.5 in
D) 4.0 in
*Rationale: NEC 300.34 requires the bending radius to be not less
than 5 times the conductor diameter. 3/0 AWG THHN diameter ≈0.7
inches, 5×0.7=3.5 inches.*
11. A motor branch circuit has a full-load current of 34 A. What is the
minimum ampacity of the branch circuit conductors?
A) 34 A
B) 42.5 A
C) 51 A
D) 68 A
*Rationale: NEC 430.22 requires conductors to have ampacity not less
than 125% of motor full-load current. 34 × 1.25 = 42.5 A.*
12. Which of the following wiring methods is NOT permitted by NYC
Electrical Code for use in a building’s return air plenum?
A) MC cable
B) NM cable (Romex)
C) EMT
D) MI cable
Rationale: NYC Electrical Code (adopting NEC 300.22) prohibits NM
cable in plenums because its insulation (PVC) can emit toxic smoke.
Only metal-clad, EMT, and mineral-insulated cables are allowed.
