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 possible answer choices. Test questions come from the Missouri Commercial 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. When starting an engine:

Explanation
After a vehicle is started, the warning lights and buzzers should go out after a few seconds. If the warning signals do not turn off, there may be something wrong with the vehicle.

2. Which of the following is not a good rule when using turn signals?

Explanation
When using your turn signals, you should signal well before the turn or lane change, signal continuously throughout the turn or lane change, and cancel the signal after you have completed your move.

3. Air brakes use ____ to function.

Explanation
Air brakes function through the use of compressed air.

4. When driving a vehicle equipped with an Anti-Lock Braking System (ABS), you should:

Explanation
Drivers of vehicles equipped with ABS and drivers of vehicles without ABS should brake in relatively the same manner. When ABS is working properly, it automatically applies when brakes are applied in situations that may create lockup.

5. Brake linings should be:

Explanation
Brake linings should not be loose or soaked with oil or grease. They shouldn't be dangerously thin.

6. Hydroplaning happens most often when:

Explanation
Hydroplaning is most likely to occur when driving on wet roads with tire pressure that is too low and tire tread that is too worn. If there is enough water on the road, hydroplaning can occur at speeds as low as 30 mph.

7. When loading a trailer, it is important to:

Explanation
A load of cargo must be properly balanced. Placing too much weight over an axle can damage the axle and make it more difficult for you to steer. Placing too little weight over an axle can cause poor traction, also leading to difficult handling.
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