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 Iowa 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. An application pressure gauge shows:

Explanation
If a vehicle is equipped, an application pressure gauge shows how much air pressure is being applied to the brakes. This gauge can help a driver identify if their brakes are beginning to fade.

2. Skids caused by over-acceleration can usually be resolved by:

Explanation
A skid caused by over-acceleration can be resolved simply by removing your foot from the accelerator. Skids of this nature happen most frequently on surfaces covered in snow or ice.

3. The only way to sober up after consuming alcohol is to:

Explanation
Most alcohol is removed from the body by the liver, which processes alcohol at a fixed rate. Despite popular belief, techniques like drinking black coffee or taking a cold shower will not accelerate this process. The only thing you can do to become sober after drinking is allow your body the time it needs to eliminate the alcohol from your system.

4. When driving at night, you should do all of the following, except:

Explanation
To ensure that you can see as well as possible, don't wear sunglasses when driving at night. If you wear eyeglasses, make sure they are clean and unscratched. Make sure you are rested and alert before driving at night.

5. During a pre-trip inspection, belts should be:

Explanation
When inspecting your vehicle, you should check all belts for tightness and excessive wear. You should learn how much "give" is appropriate for each belt.

6. In cool weather, as the temperature begins to rise and ice begins to melt:

Explanation
As the temperature begins to rise and ice on the road begins to melt, the road surface will often become even more slippery. Water from the slight melting will sit on top of the ice, decreasing the available traction even more. Always decrease your speed and drive with caution when traveling on slippery surfaces.

7. You must have an air brake endorsement:

Explanation
You must take an air brakes knowledge test to become licensed to operate a vehicle that is equipped with air brakes, including an air over hydraulic braking system.
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