Knowledge Test Class B #2
Class B Driving Test | District Of Columbia 2026 #2 Page 5 of 7
Train for FREE online with our District Of Columbia 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 DC CDL class B permit in 2026, 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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29 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
30 . Most CDL holders have ____ licenses.
Non-exempted
Most CDL holders who drive CMVs in interstate commerce are non-excepted interstate commerce drivers.
31 . In a vehicle with dual air brakes, what happens if one system is low on pressure?
The low system will use an auxiliary system to fill the tank.
In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.
32 . Some air brake systems use alcohol:
To reduce the risk of rust forming on air brake valves.
Some air brake systems contain an alcohol evaporator. This device introduces alcohol into the braking system to inhibit the formation of ice.
33 . While driving, spring brakes are generally held in place by:
Sturdy ties.
While driving, spring brakes are generally held in place by air pressure. If the air pressure gets low enough, the springs will activate the brakes.
34 . When approaching a curve during the on-road driving test, you must do all of the following, except:
Steadily use the brakes throughout the curve.
When approaching a curve during the on-road driving test, you should thoroughly check traffic in all directions. Before entering the curve, reduce your speed sufficiently so that further braking or shifting is not required. Keep your vehicle in its lane and continue checking traffic in all directions.
35 . Hydroplaning occurs when:
Front tires have less traction than rear tires.
Hydroplaning is an effect that occurs on wet roads when tires lose traction with the road surface and begin gliding along on a layer of water.
See the exact questions that will be on the 2026 District Of Columbia DMV exam.
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2026 District Of Columbia | Frequently Asked Questions
To acquire a CDL Hazmat endorsement in the District of Columbia, you must first hold a valid CDL. Then, pass the Hazardous Materials Knowledge Test at a DMV service location. You'll also need to undergo a federal TSA background check and fingerprinting. Lastly, submit the Hazmat Endorsement Application, proof of U.S. citizenship or legal status, and pay the required fees.
To obtain a CDL Hazmat license, you must already hold a valid Commercial Driver's License (CDL). You also need to pass the Hazardous Materials Knowledge Test, undergo a federal TSA background check, and be fingerprinted. Proof of U.S. citizenship or legal status is required. Lastly, you need to be in good physical health to meet the demands of the job.
When applying for a CDL Hazmat endorsement, you'll need to provide your valid Commercial Driver's License (CDL), proof of U.S. citizenship or legal residency (like a passport or birth certificate), and proof of identity. You'll also need to bring the receipt for your TSA background check and fingerprinting, and complete the Hazmat Endowment Application.
Yes, there is a dedicated written test for the CDL Hazmat endorsement. This test focuses on the rules and safety procedures for handling and transporting hazardous materials. It's essential to study the Hazmat section of your state's CDL manual thoroughly before taking the test to ensure you're well-prepared.
The written test for the CDL Hazmat endorsement covers a range of topics related to hazardous materials. These include identifying hazardous materials, understanding shipping papers, using placards and labels, handling emergencies, loading and unloading procedures, and complying with the relevant safety rules and regulations.
Yes, there are extra charges associated with acquiring a CDL Hazmat endorsement. These include fees for the TSA background check and fingerprinting, which typically cost around $86.50. Additionally, there may be a fee for the endorsement application, which varies by state. It's best to check with your local DMV for specific costs.
Yes, obtaining a CDL Hazmat endorsement requires a mandatory background check and fingerprinting conducted by the Transportation Security Administration (TSA). This ensures the individual doesn't pose a security threat and is part of the federal safety regulations for handling hazardous materials.
Yes, specialized training is mandatory for the CDL Hazmat endorsement. Applicants must pass a written test that covers the regulations and requirements for transporting hazardous materials. After passing the test, they receive a certification, which is the Hazmat endorsement on their Commercial Driver's License (CDL). This ensures they are knowledgeable about handling hazardous materials safely.
No, you cannot legally transport hazardous materials without a valid CDL Hazmat endorsement. This endorsement ensures that you have the necessary knowledge and skills to handle hazardous materials safely. Driving without it can result in serious penalties, including fines and suspension of your commercial driver's license.
Yes, you can add a Hazmat endorsement to your existing CDL. You don't need to apply for a new CDL. However, you must pass a written Hazmat knowledge test, submit to a TSA background check, and pay the associated fees. Once these steps are completed successfully, the Hazmat endorsement will be added to your CDL.
