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The CDL general knowledge test is required to be taken by all CDL applicants. The District of Columbia CDL test consists of 50 questions. To pass, you must correctly answer at least 40 questions (80%). The general knowledge test covers the contents of the District of Columbia CDL Manual. All CDL applicants (Class A, B and C) must study the following sections: Driving Safely, Transporting Cargo Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Vehicle Inspection Test, Basic Control Skills Test, Road Test. In addition, the Class A CDL test will include questions based on the Combination Vehicles section. Take this CDL practice test now to prepare for the actual DC general knowledge test! To get your CDL, you must pass both the knowledge and skills tests. CDL knowledge tests include: General Knowledge, Passenger Transport, Air Brakes, Combination Vehicles, Hazardous Materials, Tanker Vehicles, Doubles/Triples, School Bus, Firefighter. Depending on what class of license (A, B or C) and endorsements you need, you must take one or more knowledge tests. A special endorsement is also required to drive certain types of vehicles. The following endorsements may be used with a Class A, B or C CDL: HazMat (H), Tank Vehicles (N), Tank Vehicles Transporting Hazardous Materials (X) and Passenger Transport (P). The School Bus endorsement (S) is only available for Class A or B CDL, and the Doubles/Triples endorsement (T) is only available for Class A driver's licenses.
1. As part of your pre-trip inspection, make sure:
the vehicle is not overloaded.
the cargo is balanced properly.
your cargo does not obscure your view.
All of the above.
2. If your truck catches fire, the first thing you should do is to:
pull off the road and park in an open area.
pull into a service station and call for help.
get off the vehicle, open the hood and start shooting foam to keep the engine cool.
get the vehicle off the road and park near other vehicles.
3. When the road is slippery, you should:
release the accelerator and push in the clutch.
apply the brakes, then let the wheels turn freely.
slightly increase your speed to reach the next stop.
reduce your speed.
4. Which of the following vehicles is most likely to turn over?
5 axle tractor semitrailer
Triple trailer
3 axle tractor semitrailer
65 ft. conventional double
5. To back safely, you should NOT:
use a helper whenever possible.
back as slowly as possible and use the lowest reverse gear.
look at your line of travel before you begin backing.
back to the right side whenever possible.
6. Blood Alcohol Concentration (BAC) is determined by:
the type of alcohol you drink.
the amount of alcohol you drink.
how frequently you drink.
All of the above.
7. How do you find out how many seconds of following distance you have?
Wait until the vehicle ahead of you passes a pavement marking, shadow or landmark. Then count off the seconds until you reach the same spot.
Wait until the vehicle ahead of you passes a pavement marking or some other clear landmark, then use the stopwatch on your mobile phone to see how long it takes you to reach the same spot.
Pass a stationary object and count how many seconds it takes the vehicle ahead of you to reach the same spot.
None of the above.
8. Under a pressurized system, the radiator cap:
should be removed when the coolant is hot.
should always be cool.
should never be hot.
should never be removed until the system has cooled.
9. Do NOT use a B:C fire extinguisher on:
grease fires.
wood fires.
electrical equipment fires.
gasoline fires.
10. To test your hydraulic brakes for leaks:
apply firm pressure to the brakes for five seconds, then pump them three times.
pump the brake pedal three times, then hold it down for five seconds.
turn off the engine and and listen for leaks.
None of the above.
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CDL Knowledge Test DC

Number of questions: 50
Correct answers to pass:40
Passing score:80%
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