Master Electrician Licensing Exam practice test
Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
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1. The National Electrical Code (NEC) requires a minimum of how
many inches of working space in front of electrical equipment rated
600 volts or less?
A) 24 inches
B) 30 inches
C) 36 inches
D) 42 inches
Rationale: NEC 110.26 requires at least 36 inches of clear working space
in front of equipment.
2. In a 3-phase, 4-wire wye system, the line-to-neutral voltage is 208V.
What is the line-to-line voltage?
A) 208V
B) 240V
C) 360V
D) 480V
Rationale: Line-to-line voltage in a wye system = line-to-neutral × √3 =
208 × 1.732 ≈ 360V.
,3. Which conductor material provides the best conductivity for
standard building wiring?
A) Aluminum
B) Copper
C) Steel
D) Iron
Rationale: Copper offers the highest conductivity and flexibility.
4. The NEC requires GFCI protection for receptacles in which of the
following locations?
A) Bedrooms
B) Bathrooms
C) Living rooms
D) Attics
Rationale: NEC 210.8 requires GFCI in bathrooms, kitchens, garages,
outdoors, and other wet locations.
5. What is the maximum number of 12 AWG THHN wires allowed in a
3/4-inch EMT conduit?
A) 10
B) 12
C) 14
D) 16
Rationale: NEC Chapter 9, Table 1 and Annex C allow 14 conductors of
12 AWG THHN in 3/4" EMT.
6. A 20-ampere branch circuit is required to supply how many general-
purpose receptacles in a dwelling?
, A) 5
B) 6
C) 8
D) No minimum; depends on load
Rationale: NEC does not specify a minimum; branch circuits are sized
according to calculated load.
7. What is the purpose of a bonding conductor?
A) Carry current under normal conditions
B) Ensure electrical continuity and safety by connecting metal parts
C) Reduce voltage drop
D) Insulate conductors
Rationale: Bonding ensures that metal parts do not have voltage
differences, preventing shock hazards.
8. When calculating voltage drop, what is the maximum
recommended drop for feeders?
A) 1%
B) 2%
C) 3%
D) 5%
Rationale: NEC recommends a maximum of 3% voltage drop for feeders
to maintain equipment performance.
9. What is the color code for a grounded conductor in residential
wiring?
A) Red
B) Black
C) White
Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The National Electrical Code (NEC) requires a minimum of how
many inches of working space in front of electrical equipment rated
600 volts or less?
A) 24 inches
B) 30 inches
C) 36 inches
D) 42 inches
Rationale: NEC 110.26 requires at least 36 inches of clear working space
in front of equipment.
2. In a 3-phase, 4-wire wye system, the line-to-neutral voltage is 208V.
What is the line-to-line voltage?
A) 208V
B) 240V
C) 360V
D) 480V
Rationale: Line-to-line voltage in a wye system = line-to-neutral × √3 =
208 × 1.732 ≈ 360V.
,3. Which conductor material provides the best conductivity for
standard building wiring?
A) Aluminum
B) Copper
C) Steel
D) Iron
Rationale: Copper offers the highest conductivity and flexibility.
4. The NEC requires GFCI protection for receptacles in which of the
following locations?
A) Bedrooms
B) Bathrooms
C) Living rooms
D) Attics
Rationale: NEC 210.8 requires GFCI in bathrooms, kitchens, garages,
outdoors, and other wet locations.
5. What is the maximum number of 12 AWG THHN wires allowed in a
3/4-inch EMT conduit?
A) 10
B) 12
C) 14
D) 16
Rationale: NEC Chapter 9, Table 1 and Annex C allow 14 conductors of
12 AWG THHN in 3/4" EMT.
6. A 20-ampere branch circuit is required to supply how many general-
purpose receptacles in a dwelling?
, A) 5
B) 6
C) 8
D) No minimum; depends on load
Rationale: NEC does not specify a minimum; branch circuits are sized
according to calculated load.
7. What is the purpose of a bonding conductor?
A) Carry current under normal conditions
B) Ensure electrical continuity and safety by connecting metal parts
C) Reduce voltage drop
D) Insulate conductors
Rationale: Bonding ensures that metal parts do not have voltage
differences, preventing shock hazards.
8. When calculating voltage drop, what is the maximum
recommended drop for feeders?
A) 1%
B) 2%
C) 3%
D) 5%
Rationale: NEC recommends a maximum of 3% voltage drop for feeders
to maintain equipment performance.
9. What is the color code for a grounded conductor in residential
wiring?
A) Red
B) Black
C) White
