Knowledge Test Class B

This license is required for driving a single vehicle with a GVWR of more than 26,001 pounds, and a trailer not to exceed 10,000 pounds gross vehicle weight rating, or a vehicle designed to transport 24 or more people (including the.. Read More

This license is required for driving a single vehicle with a GVWR of more than 26,001 pounds, and a trailer not to exceed 10,000 pounds gross vehicle weight rating, or a vehicle designed to transport 24 or more people (including the driver). 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 Commercial Driver Guide. Questions come from chapters covering: Introduction, Driving Safely, Transporting Cargo Safely, Air Brakes (if applicable), Pre-Trip Vehicle Inspection Test, Basic Vehicle Control Skills Test and On-Road Driving. Endorsements that may be used with a Class B CDL are: Hazardous materials, Tank, Passenger, HazMat and Tank, Air Brakes and School bus.

Number of Question
Passing Score

1. When it’s difficult to see, such as at dawn or dusk, a driver can increase their vehicle's visibility by:

Explanation
When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

2. When approaching your vehicle as part of a pre-trip inspection, seeing fresh oil underneath the vehicle is:

Explanation
When approaching your vehicle, you should check under the vehicle for fresh oil, coolant, grease, or fuel leaks. Spotting any of these before a trip is a cause for concern.

3. What do air brakes use to make the brakes work?

Explanation
Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.

4. When loading a trailer, weight should be:

Explanation
Cargo with a high center of gravity makes a vehicle more likely to tip over than cargo with a low center of gravity. For this reason, it is important that the weight of cargo be distributed as low as possible.

5. In a dual air brake system:

Explanation
There are two air brake systems in a dual air brake system. The systems share a set of brake controls, but each system has its own tanks, hoses, and lines.

6. When are people usually the least alert?

Explanation
Most drivers are the least alert at night, especially after midnight. Therefore, crashes due to fatigued driving are more likely at night than any other time of day.

7. The minimum acceptable tread depth for rear tires is:

Explanation
When inspecting your tires, verify that there is at least 4/32 of an inch of tread depth in every major groove on the front tires, and tread depth of at least 2/32 of an inch on the other tires. Tires on the same vehicle should all be the same size.
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