Journeyman Plumber Licensing Examination
Questions And Correct Answers (Verified Answers)
Plus Rationales 2025/2026 Q&A |Already graded A+
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent backflow
C. Prevent sewer gases from entering the building
D. Improve drainage speed
Answer: C
Traps hold water to form a seal that blocks sewer gases.
2. The minimum slope for horizontal drainage piping 3 inches or smaller is:
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Most plumbing codes require a 1/4-inch-per-foot slope for proper drainage.
3. What material is commonly used for water supply lines due to flexibility
and corrosion resistance?
A. Galvanized steel
B. Cast iron
C. PEX tubing
D. Clay pipe
Answer: C
PEX is flexible, easy to install, and resistant to corrosion.
4. A vent pipe primarily serves to:
,A. Carry wastewater
B. Increase pressure
C. Allow air into the drainage system
D. Remove solids
Answer: C
Vents equalize pressure and protect trap seals.
5. Which fitting connects two pipes of different diameters?
A. Tee
B. Coupling
C. Reducer
D. Elbow
Answer: C
Reducers transition between different pipe sizes.
6. What is the standard water test pressure for residential plumbing
systems?
A. 25 psi
B. 50 psi
C. 100 psi
D. 150 psi
Answer: C
Most codes require a 100 psi pressure test for water systems.
7. Which valve is designed to stop backflow in a plumbing system?
A. Gate valve
B. Globe valve
C. Ball valve
D. Check valve
Answer: D
Check valves allow flow in one direction only.
, 8. What type of pipe is required for underground drainage?
A. Copper Type L
B. PVC or ABS
C. PEX
D. Steel
Answer: B
PVC and ABS are approved for underground drainage use.
9. The purpose of a cleanout is to:
A. Increase pressure
B. Vent the system
C. Provide access for cleaning drains
D. Measure flow
Answer: C
Cleanouts allow removal of blockages.
10. Which tool is best for cutting copper pipe?
A. Hacksaw
B. Tubing cutter
C. Pipe wrench
D. Chisel
Answer: B
Tubing cutters provide clean, square cuts.
11. What fitting is commonly used to change direction by 90 degrees?
A. Tee
B. Elbow
C. Wye
D. Coupling
Questions And Correct Answers (Verified Answers)
Plus Rationales 2025/2026 Q&A |Already graded A+
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent backflow
C. Prevent sewer gases from entering the building
D. Improve drainage speed
Answer: C
Traps hold water to form a seal that blocks sewer gases.
2. The minimum slope for horizontal drainage piping 3 inches or smaller is:
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Most plumbing codes require a 1/4-inch-per-foot slope for proper drainage.
3. What material is commonly used for water supply lines due to flexibility
and corrosion resistance?
A. Galvanized steel
B. Cast iron
C. PEX tubing
D. Clay pipe
Answer: C
PEX is flexible, easy to install, and resistant to corrosion.
4. A vent pipe primarily serves to:
,A. Carry wastewater
B. Increase pressure
C. Allow air into the drainage system
D. Remove solids
Answer: C
Vents equalize pressure and protect trap seals.
5. Which fitting connects two pipes of different diameters?
A. Tee
B. Coupling
C. Reducer
D. Elbow
Answer: C
Reducers transition between different pipe sizes.
6. What is the standard water test pressure for residential plumbing
systems?
A. 25 psi
B. 50 psi
C. 100 psi
D. 150 psi
Answer: C
Most codes require a 100 psi pressure test for water systems.
7. Which valve is designed to stop backflow in a plumbing system?
A. Gate valve
B. Globe valve
C. Ball valve
D. Check valve
Answer: D
Check valves allow flow in one direction only.
, 8. What type of pipe is required for underground drainage?
A. Copper Type L
B. PVC or ABS
C. PEX
D. Steel
Answer: B
PVC and ABS are approved for underground drainage use.
9. The purpose of a cleanout is to:
A. Increase pressure
B. Vent the system
C. Provide access for cleaning drains
D. Measure flow
Answer: C
Cleanouts allow removal of blockages.
10. Which tool is best for cutting copper pipe?
A. Hacksaw
B. Tubing cutter
C. Pipe wrench
D. Chisel
Answer: B
Tubing cutters provide clean, square cuts.
11. What fitting is commonly used to change direction by 90 degrees?
A. Tee
B. Elbow
C. Wye
D. Coupling
