Nunavut Plumber Certification Exam Questions
And Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Which of the following materials is commonly used for potable
water supply in residential plumbing?
A. Cast iron
B. PVC
C. Copper
D. Galvanized steel
Copper is widely used for potable water because it is durable,
corrosion-resistant, and safe for drinking water.
2. What is the primary purpose of a trap in a plumbing system?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Filter debris
D. Regulate temperature
A trap holds water to block sewer gases while allowing waste to
pass through.
3. The minimum slope for a horizontal drain pipe is typically:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/4 inch per foot for pipes up to 3 inches
D. 1/2 inch per foot
Code requires a slope of 1/4 inch per foot for small drains to
maintain flow and prevent blockages.
,4. Which valve is commonly used to prevent backflow in a potable
water system?
A. Gate valve
B. Ball valve
C. Check valve
D. Globe valve
A check valve allows water to flow in only one direction,
preventing contamination.
5. What is the typical purpose of a vent pipe in a plumbing system?
A. Carry waste water
B. Allow air to enter the drainage system to prevent siphoning of
traps
C. Heat water
D. Regulate pressure in the water main
Vent pipes maintain air pressure in drains and prevent traps from
losing their water seal.
6. Which of the following is the most common method to join
copper tubing?
A. Threaded
B. Solvent weld
C. Compression
D. Soldering (sweating)
Soldering creates a watertight connection and is standard for
copper tubing in plumbing.
7. What is the main reason to use PEX piping in residential
plumbing?
A. Low cost
, B. Heat resistance only
C. Flexibility and ease of installation
D. Corrosion resistance only
PEX is flexible, easy to install, and resistant to scale and corrosion.
8. What is the minimum water pressure required for a residential
plumbing system?
A. 20 psi
B. 30 psi
C. 40 psi
D. 50 psi
Most plumbing codes require at least 40 psi to ensure proper
fixture operation.
9. Which of the following is a sign of a water leak in a residential
system?
A. Noisy pipes
B. Higher water bills
C. Hot water availability
D. Low water pressure
Sudden increases in water bills can indicate leaks in pipes or
fixtures.
10. What is the purpose of a pressure-reducing valve (PRV)?
A. Increase water pressure
B. Maintain hot water
C. Reduce incoming water pressure to a safe level
D. Prevent backflow
A PRV prevents damage to pipes and fixtures by lowering excessive
municipal water pressure.
And Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Which of the following materials is commonly used for potable
water supply in residential plumbing?
A. Cast iron
B. PVC
C. Copper
D. Galvanized steel
Copper is widely used for potable water because it is durable,
corrosion-resistant, and safe for drinking water.
2. What is the primary purpose of a trap in a plumbing system?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Filter debris
D. Regulate temperature
A trap holds water to block sewer gases while allowing waste to
pass through.
3. The minimum slope for a horizontal drain pipe is typically:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/4 inch per foot for pipes up to 3 inches
D. 1/2 inch per foot
Code requires a slope of 1/4 inch per foot for small drains to
maintain flow and prevent blockages.
,4. Which valve is commonly used to prevent backflow in a potable
water system?
A. Gate valve
B. Ball valve
C. Check valve
D. Globe valve
A check valve allows water to flow in only one direction,
preventing contamination.
5. What is the typical purpose of a vent pipe in a plumbing system?
A. Carry waste water
B. Allow air to enter the drainage system to prevent siphoning of
traps
C. Heat water
D. Regulate pressure in the water main
Vent pipes maintain air pressure in drains and prevent traps from
losing their water seal.
6. Which of the following is the most common method to join
copper tubing?
A. Threaded
B. Solvent weld
C. Compression
D. Soldering (sweating)
Soldering creates a watertight connection and is standard for
copper tubing in plumbing.
7. What is the main reason to use PEX piping in residential
plumbing?
A. Low cost
, B. Heat resistance only
C. Flexibility and ease of installation
D. Corrosion resistance only
PEX is flexible, easy to install, and resistant to scale and corrosion.
8. What is the minimum water pressure required for a residential
plumbing system?
A. 20 psi
B. 30 psi
C. 40 psi
D. 50 psi
Most plumbing codes require at least 40 psi to ensure proper
fixture operation.
9. Which of the following is a sign of a water leak in a residential
system?
A. Noisy pipes
B. Higher water bills
C. Hot water availability
D. Low water pressure
Sudden increases in water bills can indicate leaks in pipes or
fixtures.
10. What is the purpose of a pressure-reducing valve (PRV)?
A. Increase water pressure
B. Maintain hot water
C. Reduce incoming water pressure to a safe level
D. Prevent backflow
A PRV prevents damage to pipes and fixtures by lowering excessive
municipal water pressure.
