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 or four 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), 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 you must travel down a hill, when should you switch into a lower gear?

Explanation
You should always slow down and shift into a lower gear before starting down a hill. If you do not begin to drive down a hill at a low enough speed, you risk overusing your brakes, causing them to overheat and fade.

2. If you have more than one license:

Explanation
All states share driver information through a computerized database in order to prevent the issuance of multiple licenses to a single person. It is prohibited for a person to have more than one driver license.

3. Header boards:

Explanation
Front-end header boards, also known as "headache racks," protect the driver from cargo moving in the event of a crash or emergency stop.

4. What is a drawback of retarders?

Explanation
A retarder is a device that helps to slow a vehicle, reducing the need for a driver to use the brakes. However, these devices can be noisy and are not permitted everywhere.

5. Overloading a vehicle with cargo:

Explanation
Overloading a vehicle can have negative effects on steering, braking, and speed control. Learn to recognize when cargo is overloaded or poorly balanced.

6. Pre-trip inspections should be done:

Explanation
A pre-trip inspection should be completed in the same way before every drive. Consistency will help you learn all of the proper steps and decrease the likelihood that you will forget to check something.

7. What is the minimum number of tie-downs required to secure a 10-foot piece of cargo?

Explanation
On flatbed trailers and trailers without sides, cargo must be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.
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