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The CDL general knowledge test is required to be taken by all CDL applicants. The Iowa 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 Iowa 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 IA 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. Transporting livestock requires special attention. Why?
Because livestock can move around in a trailer.
Because livestock can lean on curves.
All of the above.
2. ABS will:
increase your average speed.
shorten your stopping distance.
not change your normal braking capability.
3. When traction is poor, as in rain or snow, you should speed up very gradually. If you don't:
you could lose control.
you will exceed the speed limit.
the brakes will not work.
4. In which of the following situations should you check your mirrors more often?
When driving on a single lane road.
When driving on a narrow road.
When changing lanes or merging.
5. A cardboard box on the road:
may contain some solid material capable of causing damage.
will never damage vehicle parts if driven over.
is likely to be empty and should not be considered a hazard.
6. Drivers who must stop on a road or the shoulder of any road must put out their emergency warning devices within:
20 minutes
10 minutes
5 minutes
7. During a pre-trip inspection, you discover a power steering leak. You should:
report the problem and make arrangements to use another vehicle.
report the problem after your trip and try to stay on schedule.
report the problem and start your trip, driving slower than normal.
8. How can you avoid rolling back when you start your vehicle?
Accelerate quickly so the vehicle does not jerk.
Partly engage the clutch before you take your right foot off the brake.
Use stab braking before you engage the clutch.
9. Name two situations in which it may not be safe to operate your vehicle at legal maximum weights.
In heavy traffic or at night
During bad weather or in mountains
Over bridges or through tunnels
10. Controlled braking:
involves locking the wheels and then releasing the brakes.
must be used when you need to turn sharply while braking.
can be used to keep your vehicle in a straight line and allow you to turn if necessary.
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CDL Knowledge Test IA

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