Combination Vehicles Practice Test | Iowa 2024 #2

Train for FREE online with our Iowa CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a IA combination license in 2024, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

1 . Having anti-lock brakes on only one axle:

Will not make a difference in braking.

Will provide increased control in braking.

Will likely cause the air brakes to malfunction.

If a vehicle has anti-lock brakes on just one axle, the driver will still have more control during braking than they would without any anti-lock brakes.

2 . Fully-loaded rigs:

Usually are very responsive to steering.

Are more likely to roll over than empty rigs.

Can stop quickly.

Fully-loaded rigs are more vulnerable to rolling over than empty rigs because the weight of the cargo gives the vehicles higher centers of gravity.

3 . A trailer that is too high:

May not couple correctly.

Will couple securely.

Is not an issue.

Before coupling together a tractor and a trailer, you should make sure the trailer is at the proper height. If the trailer is too low, the trailer nose may be damaged. If the trailer is too high, it may not be able to couple correctly.

4 . A tractor protection valve:

Keeps air in a brake system if there is a bad leak.

Prevents a truck from being stolen.

Prevents a trailer from being accidentally released.

A tractor protection valve keeps air in a tractor or truck air brake system should the trailer break away or develop a bad leak. The valve will close automatically if the pressure drops to an unsafe level.

5 . A driver should test the tractor protection valve by:

Pulling the yellow, diamond-shaped knob.

Releasing air with the brake pedal.

Unlocking the trailer doors.

You should test the tractor protection valve by allowing the air supply to properly charge, turning off the engine, then releasing air from the system by pressing the brake pedal several times. The tractor protection valve should move into its emergency position when psi drops to an unsafe level.

6 . If unsure if a trailer has an Anti-Lock Braking System (ABS), you can:

Look under the trailer for wheel speed sensors coming from the back of the brakes.

Remove a tire and look for the ABS sensor on the axle.

Assume it does have ABS.

If you do not know whether or not a trailer is equipped with ABS, look under the vehicle for the electronic control unit and wheel speed sensor wires coming from the back of the brakes.

7 . If the emergency air line loses pressure:

The Anti-Lock Braking System will activate.

The service air line will activate.

The emergency brakes will activate.

The emergency air line controls the emergency brakes on a combination vehicle. A loss of air pressure in the emergency line will cause the emergency trailer brakes to activate.

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2024 Iowa | Frequently Asked Questions

A CDL Class B license in Iowa is designated for drivers operating vehicles with a Gross Vehicle Weight Rating (GVWR) exceeding 26,000 pounds, or towing vehicles not exceeding 10,000 pounds. This includes buses, dump trucks, straight trucks, and other large freight trucks. Drivers must pass knowledge and skills tests to obtain this license. Age and health requirements also apply.

A Class B CDL license in Iowa allows the holder to operate single vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 or more pounds, or any such vehicle towing another not in excess of 10,000 pounds. This includes large passenger buses, segmented buses, straight trucks, dump trucks, delivery trucks, and utility trucks.

To acquire a Class B CDL license in Iowa, applicants must be at least 18 years old (21 for interstate driving), possess a valid non-commercial driver's license, and pass a vision test. They must also pass a general knowledge test and a skills test, which includes a pre-trip vehicle inspection, a basic controls test, and a driving test. Medical examinations are also required.

To qualify for a Class B Commercial Driver's License (CDL) in Iowa, you must be at least 18 years old. However, you must be 21 years or older if you plan to drive across state lines, carry hazardous materials, or drive a vehicle designed to transport 16 or more passengers, including the driver.

Specific endorsements aren't necessary for a Class B CDL license, but they can enhance your license. Endorsements allow you to drive certain types of vehicles, like school buses, tank vehicles, or vehicles carrying hazardous materials. To get an endorsement, you'll need to pass additional written and skills tests.

The Class B CDL skills assessment in Iowa includes a pre-trip vehicle inspection, where you demonstrate knowledge about your vehicle and its safety. It also includes a basic controls test, where you show your ability to control the vehicle. Lastly, it encompasses a driving test, where you demonstrate safe driving practices on public roads.

Yes, Class B CDL license holders in Iowa are limited to operating vehicles under 26,001 pounds or towing vehicles not exceeding 10,000 pounds. They can drive buses, farm labor vehicles, and any fire-fighting or emergency vehicles. However, they cannot operate Class A vehicles without the proper endorsements. Interstate driving is not allowed until the age of 21.

Yes, in Iowa, the written Class B CDL test can be taken in Spanish. However, the Federal Motor Carrier Safety Administration requires all commercial drivers to read and speak English sufficiently to converse with the general public, understand highway traffic signs and signals, respond to official inquiries, and make entries on reports and records.

Yes, accommodations can be made for individuals with disabilities taking the Class B CDL written exam in Iowa. You need to request these accommodations in advance when scheduling your exam. Accommodations may include extended time, a separate testing room, or use of assistive technology. Always check with your local DMV office for specific procedures and requirements.

Yes, if you don't pass the Class B CDL written test in Iowa, you can retake it. However, you must wait at least one day before retaking the test. There may be additional fees for each retest. If you fail the test several times, you might be required to wait a longer period before your next attempt.