New Jersey Master Plumber Examination
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A
1. Which code governs plumbing installations in New Jersey?
| | | | | | |
A. International Plumbing Code (IPC) | | |
B. Uniform Plumbing Code (UPC) | | |
C. New Jersey State Plumbing Subcode
| | | |
D. National Standard Plumbing Code | | |
Correct Answer: C | |
The New Jersey State Plumbing Subcode, based on the IPC with state
| | | | | | | | | | |
amendments, is the legally adopted standard.
| | | | | |
2. A master plumber in New Jersey is responsible for which of the
| | | | | | | | | | |
following?
|
A. Only residential plumbing work
| | |
B. Supervising journeymen and apprentices | | |
C. Gas piping only | |
D. Design work only | |
Correct Answer: B | |
A master plumber is legally responsible for supervising plumbing work
| | | | | | | | |
and personnel.
| |
3. What is the minimum size of a building sewer serving a one-family
| | | | | | | | | | |
dwelling?
|
, A. 3 inches
|
B. 4 inches
|
C. 5 inches
|
D. 6 inches
|
Correct Answer: B
| |
The minimum building sewer size for a single-family dwelling is 4 inches.
| | | | | | | | | | |
4. Which material is prohibited for potable water distribution?
| | | | | | |
A. Copper
B. CPVC
C. Galvanized steel |
D. ABS
Correct Answer: D
| |
ABS is not approved for potable water distribution systems.
| | | | | | | |
5. What fitting must be used to change direction horizontally in a
| | | | | | | | | |
drainage system?
| |
A. Sanitary tee |
B. Long-turn wye |
C. Vent tee |
D. Pressure elbow |
Correct Answer: B
| |
Long-turn fittings are required to maintain flow characteristics in
| | | | | | | |
drainage systems.
| |
6. What is the maximum trap arm length for a 2-inch pipe under
| | | | | | | | | | |
standard conditions?
| |
A. 3 feet |
B. 5 feet |
, C. 8 feet |
D. 10 feet |
Correct Answer: C | |
Trap arm length is limited to prevent siphonage and maintain trap seals.
| | | | | | | | | | |
7. Which valve is required at the water service entrance?
| | | | | | | |
A. Check valve |
B. Gate valve |
C. Full-open shutoff valve | |
D. Relief valve |
Correct Answer: C | |
A full-open shutof f valve allows complete control of the water supply.
| | | | | | | | | | |
8. What is the minimum slope for a 3-inch horizontal drainage pipe?
| | | | | | | | | |
A. 1/8 inch per foot | | |
B. 1/4 inch per foot | | |
C. 1/2 inch per foot | | |
D. No slope required | |
Correct Answer: B | |
Pipes 3 inches and smaller require a minimum slope of 1/4 inch per foot.
| | | | | | | | | | | | |
9. What device protects a water heater from excessive pressure?
| | | | | | | |
A. Check valve |
B. Expansion tank |
C. Pressure relief valve | |
D. Vacuum breaker |
Correct Answer: C | |
A pressure relief valve prevents dangerous overpressure conditions.
| | | | | | |
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A
1. Which code governs plumbing installations in New Jersey?
| | | | | | |
A. International Plumbing Code (IPC) | | |
B. Uniform Plumbing Code (UPC) | | |
C. New Jersey State Plumbing Subcode
| | | |
D. National Standard Plumbing Code | | |
Correct Answer: C | |
The New Jersey State Plumbing Subcode, based on the IPC with state
| | | | | | | | | | |
amendments, is the legally adopted standard.
| | | | | |
2. A master plumber in New Jersey is responsible for which of the
| | | | | | | | | | |
following?
|
A. Only residential plumbing work
| | |
B. Supervising journeymen and apprentices | | |
C. Gas piping only | |
D. Design work only | |
Correct Answer: B | |
A master plumber is legally responsible for supervising plumbing work
| | | | | | | | |
and personnel.
| |
3. What is the minimum size of a building sewer serving a one-family
| | | | | | | | | | |
dwelling?
|
, A. 3 inches
|
B. 4 inches
|
C. 5 inches
|
D. 6 inches
|
Correct Answer: B
| |
The minimum building sewer size for a single-family dwelling is 4 inches.
| | | | | | | | | | |
4. Which material is prohibited for potable water distribution?
| | | | | | |
A. Copper
B. CPVC
C. Galvanized steel |
D. ABS
Correct Answer: D
| |
ABS is not approved for potable water distribution systems.
| | | | | | | |
5. What fitting must be used to change direction horizontally in a
| | | | | | | | | |
drainage system?
| |
A. Sanitary tee |
B. Long-turn wye |
C. Vent tee |
D. Pressure elbow |
Correct Answer: B
| |
Long-turn fittings are required to maintain flow characteristics in
| | | | | | | |
drainage systems.
| |
6. What is the maximum trap arm length for a 2-inch pipe under
| | | | | | | | | | |
standard conditions?
| |
A. 3 feet |
B. 5 feet |
, C. 8 feet |
D. 10 feet |
Correct Answer: C | |
Trap arm length is limited to prevent siphonage and maintain trap seals.
| | | | | | | | | | |
7. Which valve is required at the water service entrance?
| | | | | | | |
A. Check valve |
B. Gate valve |
C. Full-open shutoff valve | |
D. Relief valve |
Correct Answer: C | |
A full-open shutof f valve allows complete control of the water supply.
| | | | | | | | | | |
8. What is the minimum slope for a 3-inch horizontal drainage pipe?
| | | | | | | | | |
A. 1/8 inch per foot | | |
B. 1/4 inch per foot | | |
C. 1/2 inch per foot | | |
D. No slope required | |
Correct Answer: B | |
Pipes 3 inches and smaller require a minimum slope of 1/4 inch per foot.
| | | | | | | | | | | | |
9. What device protects a water heater from excessive pressure?
| | | | | | | |
A. Check valve |
B. Expansion tank |
C. Pressure relief valve | |
D. Vacuum breaker |
Correct Answer: C | |
A pressure relief valve prevents dangerous overpressure conditions.
| | | | | | |
