JOURNEYMAN PLUMBER LICENSE EXAM
PRACTICE QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the minimum burial depth for a direct burial cable under a
residential driveway?
A. 12 inches
B. 18 inches
C. 24 inches
D. 30 inches
The NEC requires 18 inches for direct burial cable under residential
driveways.
2. What is the maximum allowable voltage drop for branch circuits?
A. 3%
B. 3%
C. 5%
D. 10%
Voltage drop should not exceed 3% on branch circuits per NEC
recommendations.
3. What is the minimum ampacity for a #8 AWG copper conductor?
A. 30 amps
B. 50 amps
C. 40 amps
, D. 60 amps
According to NEC Table 310.16, #8 AWG copper is rated at 50
amps at 60°C.
4. A 20-ampere branch circuit supplying receptacles in a dwelling
unit shall have what minimum wire size?
A. #12 AWG aluminum
B. #12 AWG copper
C. #14 AWG copper
D. #10 AWG copper
20-amp circuits require a minimum of #12 AWG copper per NEC.
5. What color is typically used for a grounded (neutral) conductor?
A. Green
B. White
C. Red
D. Blue
The NEC specifies white or gray for grounded conductors.
6. What is the maximum number of 12 AWG conductors allowed in a
4-inch square box that is 2-1/8 inches deep?
A. 8
B. 9
C. 10
D. 11
Based on NEC box fill calculations, a 4-inch square 2-1/8" deep box
allows 9 #12 conductors.
7. What is the standard frequency of AC power in the United States?
A. 25 Hz
B. 60 Hz
C. 50 Hz
, D. 75 Hz
U.S. power operates at 60 hertz.
8. What does GFCI stand for?
A. Grounded Fault Current Isolator
B. Ground Fault Current Indicator
C. Ground-Fault Circuit Interrupter
D. Ground Flow Current Interrupter
GFCIs protect against electrical shock by detecting ground faults.
9. What is the primary purpose of bonding?
A. To reduce voltage
B. To ensure electrical continuity and safety
C. To increase resistance
D. To insulate equipment
Bonding ensures metal parts are electrically continuous and safe.
10. How many 15-amp receptacles are permitted on a 20-amp
circuit in a commercial occupancy?
A. 8
B. 10
C. 13
D. 15
Each receptacle is considered 180 VA; 20A x 120V = 2400VA /180 =
13 outlets.
(Questions 11–50 continue in the same style)
Journeyman Plumber License Exam – Questions 51–100
PRACTICE QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the minimum burial depth for a direct burial cable under a
residential driveway?
A. 12 inches
B. 18 inches
C. 24 inches
D. 30 inches
The NEC requires 18 inches for direct burial cable under residential
driveways.
2. What is the maximum allowable voltage drop for branch circuits?
A. 3%
B. 3%
C. 5%
D. 10%
Voltage drop should not exceed 3% on branch circuits per NEC
recommendations.
3. What is the minimum ampacity for a #8 AWG copper conductor?
A. 30 amps
B. 50 amps
C. 40 amps
, D. 60 amps
According to NEC Table 310.16, #8 AWG copper is rated at 50
amps at 60°C.
4. A 20-ampere branch circuit supplying receptacles in a dwelling
unit shall have what minimum wire size?
A. #12 AWG aluminum
B. #12 AWG copper
C. #14 AWG copper
D. #10 AWG copper
20-amp circuits require a minimum of #12 AWG copper per NEC.
5. What color is typically used for a grounded (neutral) conductor?
A. Green
B. White
C. Red
D. Blue
The NEC specifies white or gray for grounded conductors.
6. What is the maximum number of 12 AWG conductors allowed in a
4-inch square box that is 2-1/8 inches deep?
A. 8
B. 9
C. 10
D. 11
Based on NEC box fill calculations, a 4-inch square 2-1/8" deep box
allows 9 #12 conductors.
7. What is the standard frequency of AC power in the United States?
A. 25 Hz
B. 60 Hz
C. 50 Hz
, D. 75 Hz
U.S. power operates at 60 hertz.
8. What does GFCI stand for?
A. Grounded Fault Current Isolator
B. Ground Fault Current Indicator
C. Ground-Fault Circuit Interrupter
D. Ground Flow Current Interrupter
GFCIs protect against electrical shock by detecting ground faults.
9. What is the primary purpose of bonding?
A. To reduce voltage
B. To ensure electrical continuity and safety
C. To increase resistance
D. To insulate equipment
Bonding ensures metal parts are electrically continuous and safe.
10. How many 15-amp receptacles are permitted on a 20-amp
circuit in a commercial occupancy?
A. 8
B. 10
C. 13
D. 15
Each receptacle is considered 180 VA; 20A x 120V = 2400VA /180 =
13 outlets.
(Questions 11–50 continue in the same style)
Journeyman Plumber License Exam – Questions 51–100
