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North Dakota CDL practice test

Getting a commercial driver's licence in North Dakota starts with the CDL knowledge tests. The content is federal: every state, North Dakota 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 Dakota driver licensing agency administers the test; the rules behind it are published by the FMCSA. Try the free North Dakota CDL practice questions below, then pick a full test.

Free North Dakota CDL practice questions

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

  1. Water that collects in the air tanks is dangerous because it can:

    • Freeze in cold weather and cause brake failure
    • Rust the brake drums
    • Make the air smell bad
    • Lower the cut-out pressure
    Show answer
    Answer: A. Freeze in cold weather and cause brake failure

    Compressed air contains moisture, and the compressor adds a little oil. Both collect at the bottom of the tanks. In cold weather the water can freeze and block the lines, so drain the tanks every day.

    Source: FMCSA CDL Manual, Section 5.1.3 (Air Tank Drains)

  2. In cold weather, how often should you check and fill the alcohol evaporator?

    • Once a month
    • Only when the low air warning comes on
    • Once at the start of winter
    • Every day
    Show answer
    Answer: D. Every day

    The evaporator puts alcohol into the air system to keep ice from forming in valves and lines. Check the level daily in cold weather, and keep draining the tanks because the alcohol does not remove the water.

    Source: FMCSA CDL Manual, Section 5.1.4 (Alcohol Evaporator)

  3. If the safety valve on an air tank releases air, it means:

    • Something is wrong and the system should be checked by a mechanic
    • The tanks are at normal pressure
    • The brakes are properly adjusted
    • The governor is working as designed
    Show answer
    Answer: A. Something is wrong and the system should be checked by a mechanic

    The safety valve opens at about 150 psi only if the governor has failed to stop the compressor. It should never release in normal operation, so a venting valve is a sign of a fault.

    Source: FMCSA CDL Manual, Section 5.1.6 (Safety Valve)

  4. What happens when you press the brake pedal harder in an air-brake vehicle?

    • The compressor shuts off
    • The spring brakes release
    • More air pressure is applied to the brakes
    • The trailer brakes release
    Show answer
    Answer: C. More air pressure is applied to the brakes

    The brake pedal controls how much air goes to the brakes. Pressing harder sends more pressure. When you let up, air is released from the chambers and the compressor must replace it.

    Source: FMCSA CDL Manual, Section 5.1.7 (The Brake Pedal)

  5. When you release the brake pedal, what happens to the air that was applying the brakes?

    • It returns to the tanks for reuse
    • It stays in the chambers until the next stop
    • It goes into the tires
    • It is let out of the brake chambers, so tank pressure drops and the compressor must replace it
    Show answer
    Answer: D. It is let out of the brake chambers, so tank pressure drops and the compressor must replace it

    Each brake application uses up stored air. Pressing and releasing the pedal repeatedly can use air faster than the compressor replaces it, which is why fanning the brakes is dangerous.

    Source: FMCSA CDL Manual, Section 5.1.7 (The Brake Pedal)

Every CDL test for North Dakota drivers

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

How the North Dakota 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 Dakota 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 Dakota CDL test questions

How many questions are on the North Dakota CDL test?

The North Dakota 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 Dakota 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 Dakota?

At the North Dakota 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 Dakota CDL practice questions?

Yes. Pick North Dakota 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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