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Drivers who want to drive combination vehicles must pass the combination vehicles test. The Iowa CDL combination test consists of 20 questions, and you'll need at least 16 correct answers to pass (80%). The test covers the combination vehicles section of the Iowa CDL Manual. Take this practice test now to prepare for the actual IA CDL combination test!
1. When driving at night you should:
always use low beams.
use your high beams when it is safe and legal to do so.
All of the above.
2. Your vehicle has hydraulic brakes. When you press the brake pedal while driving and the pedal goes to the floor, remember that:
the parking brake should never used to slow the vehicle.
shifting into neutral may help slow the vehicle.
pumping the brake pedal may generate enough hydraulic pressure to stop the vehicle.
3. When transporting cargo, the cargo should be checked:
only before the trip.
before the trip and after the first 150 miles.
before the trip and after the first 50 miles.
4. As part of the final air brake check, you should:
Check air compressor governor cut-in and cut-out pressure.
Test air leakage rate.
All of the above.
5. If you must make an emergency stop, you should:
apply the brakes as hard as you can to lock them.
brake in a way that will keep your vehicle in a straight line.
use the hand brake before the brake pedal.
6. Which of the following makes a rollover more likely?
Keeping the load centered on your rig
Keeping the cargo as close to the ground as possible
Driving quickly around turns
7. Which of the following is true about the trailer hand valve?
The trailer hand valve works the trailer brakes.
It should be used only to test the trailer brakes.
All of the above.
8. Which of the following is NOT part of testing the trailer service brakes?
Releasing the parking brakes.
Moving the vehicle forward slowly.
Pushing in the trailer air supply knob.
9. The only way to stop a front-wheel skid is to:
let the vehicle slow down.
supply more power to the drive wheels.
10. It's very important to distribute the cargo so it is:
as low as possible.
as high up as possible.
in the centre of the load.
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IA CDL Combination Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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