Illinois Journeyman Electrician
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the standard color for a grounding conductor in residential
wiring?
A. Black
B. Red
C. Green
D. White
Green is the standard color for grounding conductors according to
the NEC.
2. A 20-amp branch circuit requires what minimum wire size?
A. 12 AWG
B. 12 AWG
C. 14 AWG
D. 10 AWG
12 AWG copper wire is the minimum for a 20-amp circuit per NEC
Table 310.15(B)(16).
3. What is the maximum number of 20-amp receptacles on a 20-amp
general-use branch circuit?
A. 6
B. 8
C. 10
D. 12
The NEC recommends a maximum of 10 receptacles on a 20-amp
general-purpose circuit.
,4. Which device is used to protect conductors from overcurrent?
A. Transformer
B. Circuit breaker
C. Contactor
D. Relay
Circuit breakers automatically interrupt current when an overcurrent
condition occurs.
5. What is the minimum height for installing a residential wall receptacle
above the floor?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
NEC requires wall receptacles in dwelling units to be at least 12
inches above the floor.
6. Which type of conduit is typically used outdoors and underground?
A. EMT
B. PVC
C. FMC
D. BX
PVC is nonmetallic, resistant to corrosion, and suitable for outdoor
underground installation.
7. What is the main purpose of a neutral conductor?
A. Grounding
B. Return path for current
C. Protect against shock
D. Reduce voltage drop
The neutral provides a return path for current to complete the circuit.
8. How often should GFCI protection be installed in kitchens?
A. Every outlet
B. Only for appliances
C. All countertop receptacles
D. None required
NEC requires all kitchen countertop receptacles to be GFCI protected.
, 9. What is the voltage rating for a typical residential service in Illinois?
A. 120V
B. 208V
C. 120/240V
D. 480V
Most residential services are 120/240 volts single-phase.
10. Which NEC article covers grounding and bonding?
A. Article 200
B. Article 250
C. Article 300
D. Article 310
Article 250 covers grounding and bonding requirements.
11. What is the maximum allowable voltage drop for a feeder or
branch circuit?
A. 1%
B. 2%
C. 3%
D. 5%
NEC recommends a maximum 3% voltage drop for feeders or branch
circuits for efficiency and performance.
12. A transformer has a primary voltage of 480V and secondary
voltage of 120/240V. What type of transformer is it?
A. Step-up
B. Step-down
C. Isolation
D. Autotransformer
A step-down transformer reduces voltage from higher to lower
levels.
13. What is the minimum spacing for electrical boxes on a wall in a
dwelling unit?
A. 6 feet
B. No minimum spacing specified
C. 12 feet
D. 18 inches
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the standard color for a grounding conductor in residential
wiring?
A. Black
B. Red
C. Green
D. White
Green is the standard color for grounding conductors according to
the NEC.
2. A 20-amp branch circuit requires what minimum wire size?
A. 12 AWG
B. 12 AWG
C. 14 AWG
D. 10 AWG
12 AWG copper wire is the minimum for a 20-amp circuit per NEC
Table 310.15(B)(16).
3. What is the maximum number of 20-amp receptacles on a 20-amp
general-use branch circuit?
A. 6
B. 8
C. 10
D. 12
The NEC recommends a maximum of 10 receptacles on a 20-amp
general-purpose circuit.
,4. Which device is used to protect conductors from overcurrent?
A. Transformer
B. Circuit breaker
C. Contactor
D. Relay
Circuit breakers automatically interrupt current when an overcurrent
condition occurs.
5. What is the minimum height for installing a residential wall receptacle
above the floor?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
NEC requires wall receptacles in dwelling units to be at least 12
inches above the floor.
6. Which type of conduit is typically used outdoors and underground?
A. EMT
B. PVC
C. FMC
D. BX
PVC is nonmetallic, resistant to corrosion, and suitable for outdoor
underground installation.
7. What is the main purpose of a neutral conductor?
A. Grounding
B. Return path for current
C. Protect against shock
D. Reduce voltage drop
The neutral provides a return path for current to complete the circuit.
8. How often should GFCI protection be installed in kitchens?
A. Every outlet
B. Only for appliances
C. All countertop receptacles
D. None required
NEC requires all kitchen countertop receptacles to be GFCI protected.
, 9. What is the voltage rating for a typical residential service in Illinois?
A. 120V
B. 208V
C. 120/240V
D. 480V
Most residential services are 120/240 volts single-phase.
10. Which NEC article covers grounding and bonding?
A. Article 200
B. Article 250
C. Article 300
D. Article 310
Article 250 covers grounding and bonding requirements.
11. What is the maximum allowable voltage drop for a feeder or
branch circuit?
A. 1%
B. 2%
C. 3%
D. 5%
NEC recommends a maximum 3% voltage drop for feeders or branch
circuits for efficiency and performance.
12. A transformer has a primary voltage of 480V and secondary
voltage of 120/240V. What type of transformer is it?
A. Step-up
B. Step-down
C. Isolation
D. Autotransformer
A step-down transformer reduces voltage from higher to lower
levels.
13. What is the minimum spacing for electrical boxes on a wall in a
dwelling unit?
A. 6 feet
B. No minimum spacing specified
C. 12 feet
D. 18 inches
