District Of Columbia cdl Class B Knowledge Test - 2
Number of questions: 50
Passing score: 80%
Acceptable number of errors: 10
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 four possible answer choices. Test questions come from the Washington D.C. 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.
To DMV Handbooks21. How is water and compressor oil removed from the bottom of an air storage tank?
The water and oil are siphoned out of the tank.
A drain valve is opened to remove the water and oil from the tank.
The water and oil are removed automatically as the brakes are used.
A sponge is used to soak up the water and oil.