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North Carolina CDL practice test

Getting a commercial driver's licence in North Carolina starts with the CDL knowledge tests. The content is federal: every state, North Carolina included, writes its tests from the FMCSA CDL manual, so the general knowledge test has 50 questions, the endorsement tests have 20 to 30, and the passing score is 80% on each. The North Carolina driver licensing agency administers the test; the rules behind it are published by the FMCSA. Try the free North Carolina CDL practice questions below, then pick a full test.

Free North Carolina CDL practice questions

Five questions from the general knowledge, air brakes and combination vehicles banks, the three tests most North Carolina Class A applicants take first. Show the answer to read the explanation.

  1. To test the service brakes before a trip, move forward at about 5 mph and apply the brakes firmly. A problem is shown if:

    • The vehicle stops quickly
    • The vehicle pulls to one side, feels unusual, or the pedal is mushy
    • The low air warning stays off
    • The air gauge drops a few psi
    Show answer
    Answer: B. The vehicle pulls to one side, feels unusual, or the pedal is mushy

    A pull to one side, a strange feel, or a delayed, soft stop all point to brake trouble. Do the test at low speed on a flat surface before you need the brakes at highway speed.

    Source: FMCSA CDL Manual, Section 5.3.3 (Test Service Brakes)

  2. Air brakes use what to make the brakes work?

    • Hydraulic fluid under pressure
    • Electric motors at each wheel
    • Engine vacuum
    • Compressed air
    Show answer
    Answer: D. Compressed air

    Compressed air stored in tanks pushes on brake chambers that apply the brakes. The system is safe and effective, but only if it is well maintained and used properly.

    Source: FMCSA CDL Manual, Section 5 (Air Brakes: Introduction)

  3. The air compressor governor makes the compressor start pumping again ('cut-in') at about:

    • 60 psi
    • 125 psi
    • 150 psi
    • 100 psi
    Show answer
    Answer: D. 100 psi

    The governor controls when the compressor pumps air into the tanks. It cuts in around 100 psi and cuts out around 125 psi, so the tanks stay in that working range while you drive.

    Source: FMCSA CDL Manual, Section 5.1.2 (Air Compressor Governor)

  4. If the air compressor is belt driven, you should check the belt during your inspection for:

    • Proper tightness and condition
    • The manufacturer's name
    • Whether it is the same color as the fan belt
    • Nothing; compressor belts never need checking
    Show answer
    Answer: A. Proper tightness and condition

    A loose or worn belt can slip or break, and then the compressor stops supplying air. The compressor may also be gear driven, and it needs oil either from the engine or its own supply.

    Source: FMCSA CDL Manual, Section 5.1.1 (Air Compressor)

  5. Why do air storage tanks hold enough air for several brake applications?

    • So you can inflate the tires on the road
    • So the horn keeps working after the engine is off
    • So the compressor can rest between trips
    • So the brakes can still be used if the compressor stops working
    Show answer
    Answer: D. So the brakes can still be used if the compressor stops working

    The tanks are a reserve. Even with the compressor failed, the stored air lets you make several stops while you get the vehicle safely off the road.

    Source: FMCSA CDL Manual, Section 5.1.3 (Air Storage Tanks)

Every CDL test for North Carolina drivers

Each page has ten free sample questions, the real question count, the 80% pass mark and what the test covers.

How the North Carolina CDL knowledge test works

You take the general knowledge test first; it is required for every CDL class. Class A drivers add the combination vehicles test. Almost everyone takes the air brakes test, because skipping it puts an air brake restriction on the licence. Endorsements (hazmat, tanker, doubles/triples, passenger, school bus) each have their own knowledge test. Pass the tests and you hold a commercial learner's permit; the skills test in a truck comes later.

Fees, appointment rules and test centre locations are set by North Carolina and change over time, so check the state driver licensing agency before you go. What does not change is the content, and that is what PassRig drills.

North Carolina CDL test questions

How many questions are on the North Carolina CDL test?

The North Carolina CDL general knowledge test follows the federal model: 50 questions, 40 correct to pass. Endorsement tests are shorter: air brakes 25, hazmat 30, and combination vehicles, tanker, doubles/triples, passenger and school bus 20 each.

What is the passing score on the North Carolina CDL permit test?

80% on every knowledge test, the same pass mark used across the United States.

Where do I take the CDL knowledge test in North Carolina?

At the North Carolina state driver licensing agency (the DMV, DOT or equivalent). Check its website for locations, appointments and current fees; the test content itself comes from the FMCSA CDL manual.

Does PassRig have North Carolina CDL practice questions?

Yes. Pick North Carolina in the app and you get practice sets and mock exams built from the knowledge test content your state uses, with the real counts and the 80% line.

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