ER-1J Residential Journeyman Electrical
Exam – Practice Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the maximum number of 12 AWG conductors allowed in a
standard 20-amp residential single-gang box according to the
NEC?
a) 3
b) 4
c) 5
d) 6
The NEC allows a maximum of 5 current-carrying conductors in a
standard single-gang box, plus ground.
2. What is the minimum height above finished floor for receptacles
in a dwelling living area?
a) 12 inches
b) 18 inches
c) 24 inches
d) 15 inches
The NEC specifies a minimum of 15 inches from the floor to
receptacle outlets in dwelling areas.
,3. What is the minimum required spacing for general-use receptacles
along walls in a dwelling?
a) 6 feet
b) 12 feet
c) 15 feet
d) 10 feet
NEC requires that no point along the floor line in any wall space be
more than 6 feet from a receptacle; effectively, receptacles are
spaced a maximum of 12 feet apart.
4. In a 120/240V single-phase dwelling service, how many watts can
a 20-amp, 120-volt branch circuit safely supply continuously?
a) 1800 W
b) 2000 W
c) 1920 W
d) 2200 W
Continuous load is calculated as 80% of circuit capacity: 120V ×
20A × 0.8 = 1920 W.
5. Which type of wire is commonly used for interior residential
branch circuits?
a) UF cable
b) NM-B cable
c) SE cable
d) MC cable
NM-B (non-metallic sheathed) cable is the standard for interior
residential wiring.
6. What is the minimum size copper grounding electrode conductor
for a 200-amp residential service?
, a) 6 AWG
b) 4 AWG
c) 4 AWG
d) 2 AWG
According to NEC Table 250.66, a 200A service requires a minimum
4 AWG copper grounding electrode conductor.
7. Which type of breaker is required for a bathroom receptacle?
a) Standard 15A
b) 20A GFCI
c) 20A GFCI
d) Standard 20A
Bathroom receptacles must be protected by a GFCI-rated 20-amp
circuit.
8. What is the required ampacity for a feeder supplying a dwelling
with a 100-amp main panel?
a) 100A minimum
b) 120A minimum
c) 100A minimum
d) 125A minimum
The feeder must at minimum match the rating of the main service
panel.
9. What is the NEC minimum size copper branch circuit conductor for
a 20-amp, 120-volt kitchen countertop circuit?
a) 14 AWG
b) 12 AWG
c) 10 AWG
d) 8 AWG
Exam – Practice Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the maximum number of 12 AWG conductors allowed in a
standard 20-amp residential single-gang box according to the
NEC?
a) 3
b) 4
c) 5
d) 6
The NEC allows a maximum of 5 current-carrying conductors in a
standard single-gang box, plus ground.
2. What is the minimum height above finished floor for receptacles
in a dwelling living area?
a) 12 inches
b) 18 inches
c) 24 inches
d) 15 inches
The NEC specifies a minimum of 15 inches from the floor to
receptacle outlets in dwelling areas.
,3. What is the minimum required spacing for general-use receptacles
along walls in a dwelling?
a) 6 feet
b) 12 feet
c) 15 feet
d) 10 feet
NEC requires that no point along the floor line in any wall space be
more than 6 feet from a receptacle; effectively, receptacles are
spaced a maximum of 12 feet apart.
4. In a 120/240V single-phase dwelling service, how many watts can
a 20-amp, 120-volt branch circuit safely supply continuously?
a) 1800 W
b) 2000 W
c) 1920 W
d) 2200 W
Continuous load is calculated as 80% of circuit capacity: 120V ×
20A × 0.8 = 1920 W.
5. Which type of wire is commonly used for interior residential
branch circuits?
a) UF cable
b) NM-B cable
c) SE cable
d) MC cable
NM-B (non-metallic sheathed) cable is the standard for interior
residential wiring.
6. What is the minimum size copper grounding electrode conductor
for a 200-amp residential service?
, a) 6 AWG
b) 4 AWG
c) 4 AWG
d) 2 AWG
According to NEC Table 250.66, a 200A service requires a minimum
4 AWG copper grounding electrode conductor.
7. Which type of breaker is required for a bathroom receptacle?
a) Standard 15A
b) 20A GFCI
c) 20A GFCI
d) Standard 20A
Bathroom receptacles must be protected by a GFCI-rated 20-amp
circuit.
8. What is the required ampacity for a feeder supplying a dwelling
with a 100-amp main panel?
a) 100A minimum
b) 120A minimum
c) 100A minimum
d) 125A minimum
The feeder must at minimum match the rating of the main service
panel.
9. What is the NEC minimum size copper branch circuit conductor for
a 20-amp, 120-volt kitchen countertop circuit?
a) 14 AWG
b) 12 AWG
c) 10 AWG
d) 8 AWG
