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The CDL general knowledge test is required to be taken by all CDL applicants. The Illinois 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 Illinois 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 IL 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. To stay alert while driving, you should:
never open the window or use the air conditioner.
avoid medications that can cause drowsiness.
rely on caffeine.
All of the above.
2. What should you look for when checking tires?
Cracked valve stems
Fabric showing through the tread or sidewall
All of the above
3. If the ABS is not working:
the truck will have no brakes.
the truck will still have normal brakes.
you should immediately reduce your speed.
All of the above.
4. How can you determine your following distance?
When the vehicle ahead of you passes a stationary object such as a sign along the road, use the stopwatch on your smartphone to determine how long it takes you to reach that same object.
When the vehicle ahead of you passes a stationary object on the side of road, start counting the seconds it takes you to reach that same object.
Pass a stationary object and count how many seconds it takes the vehicle ahead of you to reach that same object.
None of the above.
5. During a trip:
you should not watch gauges as they can be misleading.
you should watch gauges to make sure that valve caps are not missing.
you should watch gauges for signs of trouble.
None of the above.
6. Which of these statements is NOT true?
BAC measures the amount of alcohol in your body.
BAC is determined by the amount of alcohol you drink, how fast you drink, and your weight.
The liver can only process ⅓ an ounce of alcohol per hour.
Alcohol doesn't affects judgment and self-control.
7. If your tires are hot, you should NOT:
stop to let the tires cool down.
once the tires have cooled down, make another stop to check the tires.
let air out of the tires so the pressure goes back to normal.
drive until you correct the cause of the overheating.
8. Before driving a vehicle with a dual air system, the air compressor should build up a minimum of _____ pressure in both the primary and secondary systems.
100 psi
10 psi
75 psi
50 psi
9. To use the controlled braking method in an emergency, you should:
apply the brakes when the wheels lock up.
pump the brake pedal 3 times.
apply your brakes all the way, and release the brakes when the wheels lock up.
apply the brakes as hard as you can without locking the wheels.
10. In order to protect yourself and others, you must be aware that children may do something hazardous because:
they tend to like trucks.
they tend to act quickly without checking traffic.
they are often found in school zones.
they don't have a driving license.
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IL CDL Practice Test

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