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 four possible answer choices. Test questions come from the Washington D.C. Commercial Driver License 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. Which of the following is not a sign of bad brake drums or shoes?

Explanation
Potential problems to check for when inspecting brakes include cracked drums; shoes or pads with oil, grease, or brake fluid on them; and shoes that are missing, broken, or worn dangerously thin.

2. What is a wig wag?

Explanation
A wig wag is a type of low air pressure warning device in an air brake system. It drops a mechanical arm into the driver's view when the air pressure in the tanks falls below 60 psi.

3. In bad weather, many drivers:

Explanation
In bad weather, particularly when visibility is poor, it is common for automobile drivers to follow closely behind trucks. Open up the distance between your vehicle and the vehicle in front of you if you are being followed too closely.

4. If you’re not sure how to handle a fire, you should:

Explanation
If you are unsure of which method is appropriate to use to extinguish a fire, you should wait for firefighters to arrive and let them handle it. This is especially important when dealing with hazardous materials fires.

5. What should happen if the air pressure in the braking system's air tanks falls below 60 psi?

Explanation
On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.

6. On newer vehicles, how do you put on the parking brake?

Explanation
On newer vehicles with air brakes, the parking brake is controlled by a yellow, diamond-shaped knob. The knob is pulled out to set the brakes, and pushed in to release them.

7. Which of the following is not a sign of fatigue?

Explanation
Driving while fatigued is dangerous. Warning signs of fatigue include difficulty focusing; repeated yawning or rubbing of the eyes; daydreaming or wandering thoughts; and drifting out of your lane.
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