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100+ Free TN CMC-A Plumbing Practice Questions

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2026 Statistics

Key Facts: TN CMC-A Plumbing Exam

100 Q

Official Exam Questions

Prov TN Contractor CIB 2026.07.13

73%

Passing Score

Prov TN Contractor CIB 2026.07.13

5 hr

Time Allowed

Prov TN Contractor CIB 2026.07.13

USD 53

Prov Exam Fee

Prov TN Contractor CIB 2026.07.13

3 years

Plumbing Experience or Degree

Prov TN Contractor CIB 2026.07.13

Tennessee Plumbing (CMC-A) Contractor Examination is the official Board/Prov open-book exam: 100 questions, 73%, 5 hours, USD 53, with Board pre-approval required (bulletin dated 2026.07.13). Official delivery is English.

Sample TN CMC-A Plumbing Practice Questions

Try these sample questions to test your TN CMC-A Plumbing exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Per the 2021 International Plumbing Code, the building drain becomes the building sewer at which point?
A.At the first cleanout inside the foundation wall
B.30 inches in developed length of pipe beyond the exterior walls of the building
C.10 feet beyond the exterior walls of the building
D.At the public sewer tap, regardless of developed length
Explanation: IPC Chapter 2 defines the building drain as the lowest drainage piping that receives soil, waste, and other drainage inside the building and that extends 30 inches in developed length of pipe beyond the exterior walls. Beyond that 30-inch point the piping is the building sewer. Tennessee CMC-A candidates should not import the UPC 2-foot rule or a 10-foot municipal rule into an IPC lookup.
2A drainage fixture unit (DFU) as used in the 2021 IPC is best described as which of the following?
A.The measured gallons per minute discharged by a fixture at peak flow
B.A relative load value assigned to a fixture to estimate probable drainage load on a pipe
C.The trap diameter of the fixture expressed as a whole number
D.The number of occupants that may use one public water closet
Explanation: IPC Section 709 uses DFU values from Table 709.1 as relative load factors, not as a measured gpm. Hunter’s method accounts for intermittent use so shared piping is sized for probable peak load rather than the impossible case of every fixture discharging at once. Continuous-flow devices are converted separately at 2 DFU per 1 gpm under Section 709.3.
3The primary purpose of a fixture trap is to do which of the following?
A.Increase the velocity of waste so solids do not settle
B.Provide a water seal that prevents sewer gas from entering the building
C.Strain solids so they never enter the drainage piping
D.Serve as the required vent for the fixture drain
Explanation: A trap retains a water seal that blocks sewer gas and vermin from entering the occupied space. IPC Chapter 10 requires each fixture to be trapped and protected against siphonage and back pressure, which is why a vent is also required. The trap is not a strainer, a velocity booster, or a substitute for a vent.
4Developed length of piping, as used for IPC vent and water-supply calculations, is measured in which manner?
A.The straight-line horizontal distance between the two endpoints
B.The length along the pipe centerline, including fittings, between the two points considered
C.The vertical rise only, ignoring horizontal offsets
D.The sum of fitting equivalent lengths only, ignoring the pipe itself
Explanation: IPC Chapter 2 defines developed length as the length of a pipeline measured along the centerline of the pipe and fittings. Isometric and vent items on the CMC-A use that centerline distance, not a plan-view shortcut. Appendix E water-sizing then applies a separate 1.2 fitting allowance to that developed length; the allowance is not a substitute for measuring the pipe.
5A cross-connection in a potable water system is best defined as which of the following?
A.Any tee that joins a hot-water branch to a cold-water branch at a mixing valve
B.An actual or potential connection between potable water and a source of contamination or pollution
C.A dielectric union between dissimilar metals
D.A water-service pipe that shares a trench with a building drain of approved material
Explanation: IPC Chapter 2 and Section 608 treat a cross-connection as any actual or potential link between the potable system and a nonpotable or contaminated source. Protection is by air gap or a listed backflow preventer matched to the hazard. An ordinary mixing-valve tee is not a cross-connection, and a dielectric union addresses galvanic corrosion, not contamination.
6Atmospheric pressure at sea level will support a water column of approximately which height, which is why a suction lift pump has a practical limit well below that theoretical value?
A.14.7 feet
B.23.0 feet
C.33.9 feet
D.43.3 feet
Explanation: Standard atmospheric pressure is about 14.7 psi. Because a 1-foot water column exerts about 0.433 psi, 14.7 ÷ 0.433 ≈ 33.9 feet. Real suction lifts are much lower because of friction, vapor pressure, and altitude. The 0.433 psi per foot and 33.9-foot theoretical lift are staple plumbing-math facts on contractor exams.
7A 40-foot horizontal building drain is installed at a uniform slope of 1/4 inch per foot. What is the total fall from the upstream end to the downstream end?
A.5 inches
B.8 inches
C.10 inches
D.12 inches
Explanation: Fall equals length times slope: 40 ft × 1/4 in/ft = 10 inches. IPC Table 704.1 requires at least 1/4 inch per foot on piping 2-1/2 inches and smaller, and 1/8 inch per foot is allowed on 3- to 6-inch piping, but the arithmetic is the same. Grade questions on the CMC-A are almost always this product.
8A 45-degree offset must gain 8 inches of offset. Using the standard 45-degree travel constant of 1.414, what is the center-to-center travel of the offset piece?
A.8.0 inches
B.9.2 inches
C.11.3 inches
D.16.0 inches
Explanation: For a 45-degree offset, travel = offset × 1.414. 8 × 1.414 = 11.312 inches, reported as 11.3 inches. The same constant comes from 1 / sin(45°). Rolling offsets use a different set-back calculation; this item is a simple two-fitting 45-degree offset.
9A water column 28 feet high stands on a gauge at the base of a riser. Using 0.433 psi per foot of water, what is the static pressure at the gauge?
A.6.5 psi
B.12.1 psi
C.16.2 psi
D.28.0 psi
Explanation: Static pressure = 28 ft × 0.433 psi/ft = 12.124 psi, which rounds to 12.1 psi. The same factor is used to convert elevation loss when sizing a water distribution system under IPC Appendix E. Do not use 0.434 or 0.5 unless the problem states that approximation.
10A dwelling contains two private bathroom groups that use 1.6-gpf water closets, one domestic kitchen sink, and one residential clothes washer. Using 2021 IPC Table 709.1, what is the total drainage fixture-unit load?
A.10 DFU
B.12 DFU
C.14 DFU
D.16 DFU
Explanation: Table 709.1 rates a bathroom group with a 1.6-gpf water closet at 5 DFU, a domestic kitchen sink at 2 DFU, and a residential clothes washer at 2 DFU. 5 + 5 + 2 + 2 = 14 DFU. Do not add the individual lavatory, tub, and water-closet values on top of the bathroom-group value; footnote f only adds fixtures that are extra to the defined group.

About the TN CMC-A Plumbing Exam

The Tennessee Plumbing (CMC-A) Contractor Examination is the official Board plumbing trade examination administered by Prov beginning July 1, 2026. The official exam has 100 questions. Passing is 73% in 5 hours. The examination is open book. Prov lists USD 53 per attempt (Tennessee Contractor Candidate Information Bulletin dated 2026.07.13). Board pre-approval is required, including three years of plumbing experience or a degree in plumbing or mechanical engineering. CMC-A covers water supply, DWV, venting, storm drainage, fixtures, fuel gas related to plumbing, isometrics, and OSHA safety. Candidates must also pass Business and Law. The Board charges a separate USD 250 initial application fee. This bank is an English-language MCQ study adaptation. It does not replace required trade experience, board approval, financial statements or bonds, or the official examination.

Assessment

Open-book computer-based multiple-choice. Prov lists 2021 IPC, 2018 or 2021 IFGC, Mathematics for Plumbers and Pipefitters (8th edition), OSHA 29 CFR 1926, and Plumbing Basics for Contractors (4th Edition, 2021). Remote Examroom testing is available.

Time Limit

5 hours

Passing Score

73% (73 of 100)

Exam Fee

USD 53 (Prov, Inc. (for the Tennessee Board for Licensing Contractors))

TN CMC-A Plumbing Exam Content Outline

6%

General Knowledge

General Knowledge (6 items)

6%

Plumbing Math

Plumbing Math (6 items)

10%

Code Requirements

Code Requirements (10 items)

3%

Fixtures and Fittings

Fixtures & Fittings (3 items)

3%

Water Heaters

Water Heaters (3 items)

4%

Storm Drainage

Storm Drainage (4 items)

10%

Fuel Gas Systems

Fuel Gas Systems (10 items)

4%

OSHA Safety

OSHA Safety (4 items)

18%

Isometrics

Isometrics (18 items)

10%

Water Supply and Distribution

Water Supply and Distribution (10 items)

20%

Drain, Waste, and Vent Systems

Drain, Waste, and Vent Systems (20 items)

6%

Tools and Installation Practices

Tools and Installation Practices (6 items)

How to Pass the TN CMC-A Plumbing Exam

What You Need to Know

  • Passing score: 73% (73 of 100)
  • Assessment: Open-book computer-based multiple-choice. Prov lists 2021 IPC, 2018 or 2021 IFGC, Mathematics for Plumbers and Pipefitters (8th edition), OSHA 29 CFR 1926, and Plumbing Basics for Contractors (4th Edition, 2021). Remote Examroom testing is available.
  • Time limit: 5 hours
  • Exam fee: USD 53

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

TN CMC-A Plumbing Study Tips from Top Performers

1Obtain Board pre-approval before paying the Prov USD 53 scheduling fee
2DWV (20 items) and isometrics (18 items) are the two heaviest official topics
3Include genuine fixture-unit, pipe-sizing, and grade calculations
4This bank is an English-language MCQ study aid, not an official Prov form

Frequently Asked Questions

How many questions are on the Tennessee CMC-A Plumbing Contractor Examination?

The official Prov examination has 100 questions. Passing is 73% within 5 hours (Tennessee Contractor Candidate Information Bulletin dated 2026.07.13).

Is Board pre-approval required for the Tennessee CMC-A exam?

Yes. The Board and Prov require pre-approval. Prov states applicants must show at least three years of plumbing experience or a degree in plumbing or mechanical engineering. The Board charges a USD 50 pre-approval request fee.

Which plumbing code is used on the Tennessee CMC-A exam?

Prov lists the 2021 International Plumbing Code and the 2018 or 2021 International Fuel Gas Code.

Do I also need the Business and Law exam?

Yes. Every new contractor applicant must pass the Tennessee Contractor Business and Law Examination in addition to any required trade examination.