Free practice test

Plumber Practice Test

Check what you know about the plumber job with 15 free questions and instant explanations.

Updated By the Career Education Institute Curriculum Team
About this practice test

15 multiple-choice questions on plumber knowledge, safety and vocabulary. Submit to see your score and explanations, or open any question’s answer as you go. Nothing is saved or shared.

Question 1 of 15What does a P-trap do?
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Answer: Blocks sewer gas with a water seal. The water seal in the trap blocks sewer gases.

Question 2 of 15A common slope for small drain pipes is:
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Answer: 1/4 inch per foot. 1/4 inch per foot is typical for smaller drain lines.

Question 3 of 15When soldering copper, you should heat:
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Answer: The fitting evenly. Heat the fitting; capillary action draws in the solder.

Question 4 of 15What prevents contaminated water from entering the potable supply?
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Answer: A backflow preventer. Backflow preventers protect drinking water.

Question 5 of 15What is the T&P valve on a water heater for?
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Answer: Relieving excess temperature and pressure. It prevents dangerous pressure buildup.

Question 6 of 15Which term matches this definition: “A copper joint made by soldering.”
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Answer: Sweat joint. Sweat joint: A copper joint made by soldering.

Question 7 of 15What does “P-trap” mean?
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Answer: A U-shaped pipe that holds water to block sewer gas from entering a building.. P-trap: A U-shaped pipe that holds water to block sewer gas from entering a building.

Question 8 of 15Which term matches this definition: “The downward pitch of a drain pipe, commonly 1/4 inch per foot for smaller pipes.”
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Answer: Slope (grade). Slope (grade): The downward pitch of a drain pipe, commonly 1/4 inch per foot for smaller pipes.

Question 9 of 15What does “Cleanout” mean?
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Answer: An access fitting used to clear blockages in drain lines.. Cleanout: An access fitting used to clear blockages in drain lines.

Question 10 of 15Which term matches this definition: “A vertical pipe that lets air into the drainage system so it flows properly.”
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Answer: Vent stack. Vent stack: A vertical pipe that lets air into the drainage system so it flows properly.

Question 11 of 15What does “T&P relief valve” mean?
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Answer: A temperature and pressure relief valve that prevents water heaters from exploding.. T&P relief valve: A temperature and pressure relief valve that prevents water heaters from exploding.

Question 12 of 15Which term matches this definition: “A measure of a fixture’s load on the plumbing system, used to size pipes.”
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Answer: Fixture unit. Fixture unit: A measure of a fixture’s load on the plumbing system, used to size pipes.

Question 13 of 15What does “PEX” mean?
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Answer: Cross-linked polyethylene tubing used for water supply lines.. PEX: Cross-linked polyethylene tubing used for water supply lines.

Question 14 of 15Which term matches this definition: “A device that stops contaminated water from flowing back into the potable supply.”
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Answer: Backflow preventer. Backflow preventer: A device that stops contaminated water from flowing back into the potable supply.

Question 15 of 15What does “Rough-in” mean?
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Answer: Installing pipes inside walls and floors before finishes go on.. Rough-in: Installing pipes inside walls and floors before finishes go on.

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