Knowledge Test Class A

This license is required for driving any legal combination of vehicles, with a gross combination weight rating of 26,001 pounds or more, provided the GVWR of a trailer exceeds 10,000 pounds To receive this license, applicants must pass a 50-question.. Read More

This license is required for driving any legal combination of vehicles, with a gross combination weight rating of 26,001 pounds or more, provided the GVWR of a trailer exceeds 10,000 pounds To receive this license, applicants must pass a 50-question test. To pass, applicants must answer 40 questions correctly. Each question has three or four possible answer choices. Test questions come from the Mississippi Professional Driver’s Manual. Questions come from chapters covering: Introduction, Driving Safely, Transporting Cargo Safely, Air Brakes (if applicable), Combination, Doubles and Hazardous Materials. Endorsements that may be used with a Class A CDL are: Hazardous materials, Tank, Passenger, HazMat and Tank, Air Brakes and School bus.

Number of Question
Passing Score

1. If using the spring brakes while hauling a heavy load, a complete stop will:

Explanation
Spring brakes will activate in a vehicle with air brakes if the pressure in the air system becomes too low. A heavily loaded vehicle will take a long time to stop when using only the spring brakes because the spring brakes do not work on all axles.

2. In a dual air brake system:

Explanation
Most heavy-duty vehicles use dual air brake systems. A dual air brake system consists of two separate air brake systems, connected by a single set of brake controls. Each system has its own air tanks.

3. The air compressor is connected to the:

Explanation
The air compressor of an air brake system is connected to the engine through gears or a v-belt. The compressor may be air-cooled or cooled by the engine cooling system.

4. A CMV should:

Explanation
All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

5. Which of the following is not a part of an air brake system?

Explanation
Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system.

6. Leaking shock absorbers:

Explanation
The suspension system keeps a vehicle's axles in place. Damaged suspension parts, such as leaking shock absorbers, may be potentially dangerous defects on a vehicle.

7. When driving through a curve during the skills test, you should:

Explanation
When approaching a curve during the on-road driving skills test, you must reduce your speed sufficiently before entering the curve so that you do not need to further brake or shift in the curve. Keep the vehicle in its lane and continue to check for traffic in all directions.
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