100+ Free Plumbing NC I Practice Questions

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2026 Statistics

Key Facts: Plumbing NC I Exam

₱1,609

Assessment Fee

TESDA Circular 072-2021

NC I

Level

TR 2014

Competency

Passing Standard

TESDA

5 years

NC Validity

TESDA

TESDA Plumbing NC I is entry-level national plumbing competency for single-unit installation. Assessment includes written and practical parts. Fee ₱1,140.

Sample Plumbing NC I Practice Questions

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

1According to TESDA Plumbing NC I, what must be done to PVC pipe ends before solvent-cement fit-up?

A.Clean the pipe ends according to standard procedures before fit-up

B.Heat the pipe ends with a blow torch until they soften

C.Apply primer only after the solvent cement has fully cured

D.Sand the interior only; the exterior does not need preparation

Explanation: Performance criteria for PVC joints require pipe ends to be properly cleaned prior to fit-up according to standard procedures, ensuring the solvent cement bonds effectively.

2When making PVC pipe joints, when should trial fitting be performed?

A.Before final fit-up and before applying solvent cement or other jointing materials

B.Only after the solvent cement has cured for 24 hours

C.After the joint is permanently connected to test for leaks

D.Trial fitting is optional if measurements are within tolerance

Explanation: The TR requires trial fitting prior to final fit-up and before application of solvent cement or other jointing materials to verify alignment.

3Which jointing material is specified in the TR for ensuring leak-free threaded pipe connections?

A.Teflon tape or other related jointing materials applied to the threads

B.Electrical tape wrapped around the outside of the fitting

C.Gasoline applied to the threads as a lubricant only

D.Chalk stone packed into the joint hub

Explanation: Element 2 of Make Piping Joints requires Teflon tape or other related jointing materials to ensure leak-free joints and connections.

4For caulked cast iron (CI) pipe joints, to what minimum depth must joints be firmly packed and fitted?

A.Not less than 25.4 mm

B.Not less than 12.7 mm

C.Exactly 50.8 mm regardless of pipe size

D.Until the joint is flush with the outside of the pipe only

Explanation: The TR specifies caulked CI joints must be firmly packed and fitted to a depth of not less than 25.4 mm and aligned with each other.

5For hubless cast iron caulked joints, how far below the rim of the hubless fitting may the caulk extend?

A.Not more than 3.2 mm below the rim of the hubless fitting

B.At least 25.4 mm below the rim

C.Flush with or above the rim of the fitting

D.Exactly 12.7 mm below the rim in all cases

Explanation: The TR states the caulked joint is extended to not more than 3.2 mm below the rim of the hubless fitting.

6What pipe materials are explicitly excluded from the Make Piping Joints and Connections unit descriptor?

A.Copper pipes and fittings

B.PVC DWV pipes and fittings

C.G.I. Schedule 40 pipes

D.HDPE pipes and fittings

Explanation: Unit CON712345 covers making pipe joints except copper pipes and fittings; copper jointing is outside this unit's scope.

7Which PVC pipe joint angles are listed in the Range of Variables for Make Piping Joints?

A.Right angle, 180°, and 30°/60°

B.Only 90° elbows with no other angles permitted

C.45° and 22.5° only

D.Any angle without measurement

Explanation: The TR Range of Variables for PVC pipe joints includes right angle, 180°, and 30°/60° configurations.

8When fitting up PVC joints, joints must be made with strict adherence to:

A.Perpendicularity and levelness of alignment per plumbing code requirements

B.Maximum pipe slope regardless of layout plans

C.Random alignment as long as solvent cement holds

D.Overlap of pipe ends by at least one pipe diameter

Explanation: PVC joints require strict adherence to perpendicularity and levelness of alignment in accordance with plumbing code requirements.

9What is used to connect hubless cast iron pipes according to the TR?

A.Couplers

B.Solvent cement only

C.Teflon tape wrapped around the outside of the pipe

D.Welding rod without a coupling

Explanation: The TR specifies couplers are used to connect pipes and fittings to hubless pipes in caulked CI work.

10Which tool is listed for cutting and preparing pipe during joint-making activities?

A.Pipe cutter and hacksaw with blade

B.Concrete cutter only

C.Paint brush

D.Framing square only

Explanation: The Range of Variables lists pipe cutter and hacksaw with blade among tools for joint work.

About the Plumbing NC I Exam

Entry-level plumbing certification practice covering pipe fittings, joints, fixtures basics, and installation knowledge.

Assessment

Performance-based assessment

Time Limit

4 to 8 hours

Passing Score

Competency-based

Exam Fee

₱1,609.00 (TESDA)

Plumbing NC I Exam Content Outline

30%

Piping Joints & Connections

Make piping joints and connections

35%

Install Pipes & Fittings

Install pipes and fittings for single plumbing units

20%

Minor Construction Work

Perform minor construction work supporting plumbing installation

15%

Safety, Tools & Plans

OHS, tools, and blueprint reading for entry-level plumbing

How to Pass the Plumbing NC I Exam

What You Need to Know

Passing score: Competency-based
Assessment: Performance-based assessment
Time limit: 4 to 8 hours
Exam fee: ₱1,609.00

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

Plumbing NC I Study Tips from Top Performers

1Know common pipe materials and jointing methods at a conceptual level.

2Practice reading simple plumbing isometric sketches.

3Review PPE and confined-space awareness for plumbing work.

4Understand trap and vent purpose without inventing unverified code article numbers.

5Prepare oral answers on leak checks after installation.

Frequently Asked Questions

What does Plumbing NC I cover?

Entry-level competencies: make piping joints/connections, perform minor construction work, and install/assemble a single plumbing unit (TR amended Oct 2014).

Fee?

Promulgated TESDA assessment fee ₱1,609.00 for Plumbing NC I Full (TESDA Circular No. 072-2021, 6 Sep 2021).

Assessment methods?

Written examination plus direct observation and demonstration with oral questioning.

Passing standard?

Competent / Not Yet Competent.

How does NC I differ from NC II?

NC I focuses on single plumbing units; NC II covers multiple units, estimation, leak testing, and repair/maintenance for medium-rise contexts.

100+ Free Plumbing NC I Practice Questions

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