Alberta Plumber Apprenticeship Certification Exam (First Period) Practice Questions And Correct Answers (Verified) Latest Update 2026/2027 | Graded A+.

Alberta Plumber Apprenticeship Certification Exam (First Period) Practice Questions And Correct Answers (Verified) Latest Update 2026/2027 | Graded A+. 1. What is the primary purpose of a trap in a drainage system? A. Provide mechanical filtration B. Prevent sewer gases from entering the building C. Increase water pressure D. Prevent pipe corrosion Rationale: Traps hold a water seal that blocks harmful sewer gases from migrating into occupied spaces. 2. What is the minimum water seal depth required for a trap? A. 25 mm B. 100 mm C. 50 mm D. 150 mm Rationale: Most codes require a 50 mm (2-inch) water seal to maintain effective gas blocking. 3. A vent prevents which of the following? A. Water hammer B. Trap siphonage C. Pipe corrosion D. Backflow Rationale: Vents equalize air pressure to prevent traps from being siphoned dry. 4. Which type of copper tube is typically used for water distribution? A. Type DWV B. Type K only C. Type L D. Type M Rationale: Type L strikes a balance between wall thickness and cost, making it suitable for water supply lines. 5. What material is commonly used for DWV systems? A. Steel B. Copper C. PEX D. PVC Rationale: PVC is lightweight, easy to install, and widely allowed in DWV systems. 8. A backflow preventer protects against… A. Clogging B. Contamination of potable water C. Pipe corrosion D. Air circulation in vents Rationale: Backflow prevention ensures contaminants cannot enter the clean water system. 9. Hard water contains high levels of: A. Sodium B. Iron C. Calcium and magnesium D. Carbon dioxide Rationale: Hardness is caused by calcium and magnesium mineral content. 10. The term “fixture unit” measures: A. Weight of a fixture B. Probable discharge load of a fixture C. Size of drain D. Pressure rating Rationale: Fixture units estimate probable demand on a drainage or water system. 11. What is the minimum size for a building drain? A. 2" B. 3" C. 4" D. 6" Rationale: Building drains normally require at least 4 inches for capacity and code compliance. 12. Galvanic corrosion occurs when: A. Water is too pure B. Dissimilar metals contact in presence of an electrolyte C. Pressure is too high D. Venting is inadequate Rationale: Different metals create an electrical reaction causing accelerated corrosion. 13. Soldering copper requires heating to approximately: A. 150°C B. 230°C C. 600°C D. 900°C Rationale: Soft solder melts between 180–230°C depending on alloy. What is the primary purpose of a cleanout? A. Increase flow velocity B. Allow water hammer control C. Provide access for cleaning the drainage system D. Prevent siphonage Rationale: Cleanouts give access points for clearing blockages. 6. What is the typical slope for a horizontal drainage pipe ≤ 3 inches? A. 1% B. 2% C. 4% D. 10% Rationale: A 2% slope (¼ inch per foot) ensures proper drainage without excessive velocity. 14. Which fitting changes pipe direction by 90°? A. Wye B. Coupling C. Elbow D. Union Rationale: Elbows are designed for directional changes, including 90°. 15. Pressure in a closed water system increases when: A. A vent is added B. Flow stops C. Water is heated D. A relief valve is removed Rationale: Thermal expansion increases pressure unless properly relieved. 16. A water hammer arrester is used to: A. Increase water pressure B. Remove air from pipes C. Absorb sudden pressure spikes D. Prevent backflow Rationale: Arresters reduce the shock caused by quick valve closures. 17. A vent stack is used to: A. Drain stormwater B. Provide air circulation in the drainage system C. Boost water pressure D. Store wastewater Rationale: Vent stacks ensure proper air movement throughout the system. 19. What is the maximum trap arm length determined by? A. Fixture units B. Pipe diameter and slope C. Vent size D. Water pressure Rationale: Trap arm limits depend on diameter and slope to maintain a functional seal. 20. The main purpose of a vent header is: