Master Electrician Licensing Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A
1. What is the maximum allowable voltage drop for a feeder circuit to
ensure efficient operation?
A) 1%
B) 3%
C) 5%
D) 10%
Rationale: NEC recommends a maximum of 5% voltage drop for
feeders and branch circuits to maintain equipment efficiency and
prevent overheating.
2. Which conductor is typically used as a grounding conductor?
A) Black
B) White
C) Green or bare copper
, D) Red
Rationale: Green or bare copper wires are designated for grounding to
provide a safe path for fault current.
3. According to the NEC, how often should arc-fault circuit interrupters
(AFCIs) be installed in dwelling unit bedrooms?
A) Only in kitchens
B) Only in living rooms
C) In all bedrooms
D) Only in garages
Rationale: NEC 210.12 requires AFCIs in all dwelling unit bedrooms to
reduce fire risk from arc faults.
4. What is the maximum ampacity of a 12 AWG copper conductor in a
residential application under normal conditions?
A) 10A
B) 15A
C) 20A
D) 25A
Rationale: According to NEC Table 310.15(B)(16), 12 AWG copper
conductors are rated for 20 amps.
5. Which device protects against overcurrent caused by short circuits or
overloads?
A) Transformer
B) Circuit breaker
, C) Contactor
D) Surge protector
Rationale: Circuit breakers are designed to interrupt current in
overload or short circuit conditions to prevent damage and fire
hazards.
6. What is the purpose of a GFCI outlet?
A) Increase voltage
B) Prevent electrocution
C) Reduce energy consumption
D) Stabilize current
Rationale: Ground-Fault Circuit Interrupters (GFCI) detect current
leakage and trip to prevent shock hazards.
7. What type of conduit is typically used outdoors and underground?
A) EMT
B) PVC
C) Flexible metal conduit
D) BX cable
Rationale: PVC conduit is corrosion-resistant and suitable for wet and
underground locations.
8. How many wires are required in a 120/240V single-phase branch
circuit with a neutral?
A) 2
B) 3
, C) 3 hot/neutral/ground
v
D) 4
Rationale: A single-phase 120/240V circuit requires two hot wires, one
v v v v v v v v v
v neutral, and typically a ground.
v v v v
9. What is the minimum burial depth for rigid metal conduit (RMC) under
v v v v v v v v v v v
v residential driveways? v
A) 12 inches v
B) 18 inches v
C) 24 inches v
D) 6 inchesv
Rationale: NEC Table 300.5 specifies 6 inches minimum burial depth
v v v v v v v v v
v for RMC under concrete driveways.
v v v v
10. Which type of load is considered continuous under NEC?
v v v v v v v v
A) Loads lasting less than 1 hour
v v v v v
B) Loads fluctuating rapidly
v v
C) Loads expected to run for 3 hours or more
v v v v v v v v
D) Motor loads only v v
Rationale: NEC defines continuous load as a load expected to operate
v v v v v v v v v v
v for three hours or more.
v v v v
11. What color is typically used for a grounded (neutral) conductor?
v v v v v v v v v
A) Black
B) Red
C) White
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A
1. What is the maximum allowable voltage drop for a feeder circuit to
ensure efficient operation?
A) 1%
B) 3%
C) 5%
D) 10%
Rationale: NEC recommends a maximum of 5% voltage drop for
feeders and branch circuits to maintain equipment efficiency and
prevent overheating.
2. Which conductor is typically used as a grounding conductor?
A) Black
B) White
C) Green or bare copper
, D) Red
Rationale: Green or bare copper wires are designated for grounding to
provide a safe path for fault current.
3. According to the NEC, how often should arc-fault circuit interrupters
(AFCIs) be installed in dwelling unit bedrooms?
A) Only in kitchens
B) Only in living rooms
C) In all bedrooms
D) Only in garages
Rationale: NEC 210.12 requires AFCIs in all dwelling unit bedrooms to
reduce fire risk from arc faults.
4. What is the maximum ampacity of a 12 AWG copper conductor in a
residential application under normal conditions?
A) 10A
B) 15A
C) 20A
D) 25A
Rationale: According to NEC Table 310.15(B)(16), 12 AWG copper
conductors are rated for 20 amps.
5. Which device protects against overcurrent caused by short circuits or
overloads?
A) Transformer
B) Circuit breaker
, C) Contactor
D) Surge protector
Rationale: Circuit breakers are designed to interrupt current in
overload or short circuit conditions to prevent damage and fire
hazards.
6. What is the purpose of a GFCI outlet?
A) Increase voltage
B) Prevent electrocution
C) Reduce energy consumption
D) Stabilize current
Rationale: Ground-Fault Circuit Interrupters (GFCI) detect current
leakage and trip to prevent shock hazards.
7. What type of conduit is typically used outdoors and underground?
A) EMT
B) PVC
C) Flexible metal conduit
D) BX cable
Rationale: PVC conduit is corrosion-resistant and suitable for wet and
underground locations.
8. How many wires are required in a 120/240V single-phase branch
circuit with a neutral?
A) 2
B) 3
, C) 3 hot/neutral/ground
v
D) 4
Rationale: A single-phase 120/240V circuit requires two hot wires, one
v v v v v v v v v
v neutral, and typically a ground.
v v v v
9. What is the minimum burial depth for rigid metal conduit (RMC) under
v v v v v v v v v v v
v residential driveways? v
A) 12 inches v
B) 18 inches v
C) 24 inches v
D) 6 inchesv
Rationale: NEC Table 300.5 specifies 6 inches minimum burial depth
v v v v v v v v v
v for RMC under concrete driveways.
v v v v
10. Which type of load is considered continuous under NEC?
v v v v v v v v
A) Loads lasting less than 1 hour
v v v v v
B) Loads fluctuating rapidly
v v
C) Loads expected to run for 3 hours or more
v v v v v v v v
D) Motor loads only v v
Rationale: NEC defines continuous load as a load expected to operate
v v v v v v v v v v
v for three hours or more.
v v v v
11. What color is typically used for a grounded (neutral) conductor?
v v v v v v v v v
A) Black
B) Red
C) White
