Journeyman Plumber Practice Exam (General)
ACTUAL EXAM QUESTIONS AND CORRECT
ANSWERS VERIFIED ANSWERS GRADED A+
1. What is the minimum slope required for a 3-inch horizontal drain?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 3/8 inch per foot
D. 1/2 inch per foot
Rationale: The minimum slope for 2½ inches or smaller drains is 1/4 inch per foot to maintain
proper flow and prevent buildup.
2. What type of fitting is used to connect two pipes at a 45° angle?
A. Tee
B. Wye
C. Elbow
D. Coupling
Rationale: A wye fitting allows a 45° branch connection, promoting smoother flow and less
turbulence than a tee.
3. What is the minimum trap seal depth required for a plumbing fixture?
A. 1 inch
B. 1 ½ inches
C. 2 inches
D. 3 inches
Rationale: Trap seals must be between 2 and 4 inches to prevent sewer gases from entering
the building.
4. Which type of pipe is most commonly used for water service lines?
A. PVC
B. ABS
C. Type K copper
D. CPVC
Rationale: Type K copper is typically used for underground water service due to its thickness
and corrosion resistance.
5. What is the purpose of a vent pipe?
A. Carry waste
B. Supply water
, C. Allow air into the drainage system
D. Seal traps
Rationale: Vent pipes admit air to maintain neutral pressure in the drainage system and
protect trap seals.
6. The minimum size of a building drain shall be:
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Rationale: Most codes require a minimum 4-inch building drain to handle combined fixture
load.
7. What type of valve is used to prevent backflow?
A. Ball valve
B. Gate valve
C. Globe valve
D. Check valve
Rationale: A check valve allows one-way flow, preventing contamination or backflow into
potable water.
8. Which material is not approved for hot water distribution?
A. CPVC
B. PVC
C. Copper
D. PEX
Rationale: PVC is not rated for hot water applications and can deform or leach chemicals when
exposed to heat.
9. What is the minimum vertical distance between a fixture outlet and the weir of the trap?
A. 12 inches
B. 6 inches
C. 24 inches
D. 30 inches
Rationale: The developed length between fixture outlet and trap weir shall not exceed 24
inches to ensure proper trap function.
10. What is the maximum distance a trap can be from a vent for a 2-inch pipe?
A. 2 feet
B. 4 feet
C. 5 feet
D. 8 feet
Rationale: The trap arm length for a 2-inch pipe can be up to 5 feet under standard code
provisions.
11. The minimum air gap for a sink faucet above the flood rim is:
A. ½ inch
ACTUAL EXAM QUESTIONS AND CORRECT
ANSWERS VERIFIED ANSWERS GRADED A+
1. What is the minimum slope required for a 3-inch horizontal drain?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 3/8 inch per foot
D. 1/2 inch per foot
Rationale: The minimum slope for 2½ inches or smaller drains is 1/4 inch per foot to maintain
proper flow and prevent buildup.
2. What type of fitting is used to connect two pipes at a 45° angle?
A. Tee
B. Wye
C. Elbow
D. Coupling
Rationale: A wye fitting allows a 45° branch connection, promoting smoother flow and less
turbulence than a tee.
3. What is the minimum trap seal depth required for a plumbing fixture?
A. 1 inch
B. 1 ½ inches
C. 2 inches
D. 3 inches
Rationale: Trap seals must be between 2 and 4 inches to prevent sewer gases from entering
the building.
4. Which type of pipe is most commonly used for water service lines?
A. PVC
B. ABS
C. Type K copper
D. CPVC
Rationale: Type K copper is typically used for underground water service due to its thickness
and corrosion resistance.
5. What is the purpose of a vent pipe?
A. Carry waste
B. Supply water
, C. Allow air into the drainage system
D. Seal traps
Rationale: Vent pipes admit air to maintain neutral pressure in the drainage system and
protect trap seals.
6. The minimum size of a building drain shall be:
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Rationale: Most codes require a minimum 4-inch building drain to handle combined fixture
load.
7. What type of valve is used to prevent backflow?
A. Ball valve
B. Gate valve
C. Globe valve
D. Check valve
Rationale: A check valve allows one-way flow, preventing contamination or backflow into
potable water.
8. Which material is not approved for hot water distribution?
A. CPVC
B. PVC
C. Copper
D. PEX
Rationale: PVC is not rated for hot water applications and can deform or leach chemicals when
exposed to heat.
9. What is the minimum vertical distance between a fixture outlet and the weir of the trap?
A. 12 inches
B. 6 inches
C. 24 inches
D. 30 inches
Rationale: The developed length between fixture outlet and trap weir shall not exceed 24
inches to ensure proper trap function.
10. What is the maximum distance a trap can be from a vent for a 2-inch pipe?
A. 2 feet
B. 4 feet
C. 5 feet
D. 8 feet
Rationale: The trap arm length for a 2-inch pipe can be up to 5 feet under standard code
provisions.
11. The minimum air gap for a sink faucet above the flood rim is:
A. ½ inch
