District Of Columbia cdl Class B Knowledge Test - 1
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 Handbooks8. Air tank drains:
Allow rain water to enter the tanks.
Are used to drain water and oil from the air tanks.
Should never be opened.
Must remain open while driving.