Knowledge Test Class B #2
Class B Driving Test | Iowa 2025 #2 Page 4 of 7
Train for FREE online with our Iowa class B license 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 CDL class B permit in 2025, 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 CDL class B requirements may vary from state to state.
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22 . The two markings on a front brake limiting valve usually read:
Some vehicles with air brake systems manufactured before 1975 have a front brake limiting valve with "normal" and "slippery" settings.
23 . Black ice is:
Black ice is a layer of ice that is thin and clear enough for the road to be visible through it. The surface will look like a wet road. Always be alert to black ice if the road looks wet when the temperature is below freezing.
24 . People working on a disabled vehicle:
Be cautious when driving near people who are working on a disabled vehicle on the side of the road. They may be focused on the repair and not paying attention to nearby traffic.
25 . During a pre-trip inspection, belts should be:
When inspecting your vehicle, you should check all belts for tightness and excessive wear.
26 . If you are being tailgated, you should:
If someone is following you too closely, you should open up the space in front of your vehicle to make it easier for the tailgater to pass. Speeding up is counterproductive because the other driver may just continue tailgating you at the higher speed, only increasing the danger.
27 . What is the average driver’s reaction time?
The average driver has a reaction time between three-quarters of a second and one second. At 55 mph, this corresponds to a distance of 61 feet traveled.
28 . What is often found in compressed air?
Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.
2025 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.