Journeyman Plumber Licensing Exam,
Questions With Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which type of pipe is commonly used for potable water
distribution in residential plumbing?
A. Cast iron
B. Galvanized steel
C. PVC
D. Asbestos cement
PVC is widely used for potable water due to its corrosion
resistance and ease of installation.
2. The minimum slope for a horizontal 3-inch drain pipe is:
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
A slope of 1/4 inch per foot ensures proper drainage and
prevents blockages.
3. The function of a P-trap is to:
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Filter debris
, D. Regulate water temperature
A P-trap holds water that acts as a barrier against sewer gases.
4. What is the most common material for residential water service
lines?
A. Copper
B. PEX
C. Cast iron
D. Lead
PEX is flexible, resistant to corrosion, and easy to install, making
it common for modern water service lines.
5. Which valve is used to control water flow in a building’s main
supply line?
A. Globe valve
B. Gate valve
C. Check valve
D. Ball valve
Gate valves are designed for on/off control in main supply lines
and are not intended for throttling.
6. A water hammer arrester is used to:
A. Increase water temperature
B. Absorb shock caused by sudden valve closure
C. Prevent leaks
D. Filter water
Water hammer arresters protect piping systems from pressure
surges.
7. Which pipe joining method is typically used with copper tubing?
A. Threaded
, B. Soldering (sweating)
C. Solvent welding
D. Compression
Sweating copper pipes ensures a watertight, durable joint.
8. The maximum distance a water heater should be from a fixture to
avoid excessive heat loss is:
A. 5 feet
B. 10 feet
C. 25 feet
D. 50 feet
Long distances increase heat loss and reduce water delivery
efficiency.
9. Which of the following is a type of backflow prevention device?
A. Gate valve
B. Pressure relief valve
C. Atmospheric vacuum breaker
D. Ball valve
An atmospheric vacuum breaker prevents contaminated water
from siphoning back into the potable water system.
10. What is the minimum air gap for a sink drain above the flood
level rim?
A. 0.5 inches
B. 1 inch
C. 2 inches
D. 3 inches
A 2-inch air gap prevents backflow and contamination of potable
water.
Questions With Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which type of pipe is commonly used for potable water
distribution in residential plumbing?
A. Cast iron
B. Galvanized steel
C. PVC
D. Asbestos cement
PVC is widely used for potable water due to its corrosion
resistance and ease of installation.
2. The minimum slope for a horizontal 3-inch drain pipe is:
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
A slope of 1/4 inch per foot ensures proper drainage and
prevents blockages.
3. The function of a P-trap is to:
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Filter debris
, D. Regulate water temperature
A P-trap holds water that acts as a barrier against sewer gases.
4. What is the most common material for residential water service
lines?
A. Copper
B. PEX
C. Cast iron
D. Lead
PEX is flexible, resistant to corrosion, and easy to install, making
it common for modern water service lines.
5. Which valve is used to control water flow in a building’s main
supply line?
A. Globe valve
B. Gate valve
C. Check valve
D. Ball valve
Gate valves are designed for on/off control in main supply lines
and are not intended for throttling.
6. A water hammer arrester is used to:
A. Increase water temperature
B. Absorb shock caused by sudden valve closure
C. Prevent leaks
D. Filter water
Water hammer arresters protect piping systems from pressure
surges.
7. Which pipe joining method is typically used with copper tubing?
A. Threaded
, B. Soldering (sweating)
C. Solvent welding
D. Compression
Sweating copper pipes ensures a watertight, durable joint.
8. The maximum distance a water heater should be from a fixture to
avoid excessive heat loss is:
A. 5 feet
B. 10 feet
C. 25 feet
D. 50 feet
Long distances increase heat loss and reduce water delivery
efficiency.
9. Which of the following is a type of backflow prevention device?
A. Gate valve
B. Pressure relief valve
C. Atmospheric vacuum breaker
D. Ball valve
An atmospheric vacuum breaker prevents contaminated water
from siphoning back into the potable water system.
10. What is the minimum air gap for a sink drain above the flood
level rim?
A. 0.5 inches
B. 1 inch
C. 2 inches
D. 3 inches
A 2-inch air gap prevents backflow and contamination of potable
water.
