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Drivers who want to drive combination vehicles must pass the combination vehicles test. The North Carolina 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 North Carolina CDL Manual. Take this practice test now to prepare for the actual NC CDL combination test!
1. Air brakes use ________ to make the brakes work.
compressed gas cylinders
compressed oil
compressed gases
compressed air
2. When looking at your cargo covers in the mirrors while driving, you must be aware that a flapping cover:
keeps the cargo cool.
helps keep the cargo as close to the ground as possible.
can tear loose, uncovering the cargo.
means that the cargo is balanced.
3. You should always try to back toward the driver's side because:
you can more easily correct any steering errors.
backing toward the left side is more dangerous.
you can watch the rear of your vehicle out the side window.
None of the above.
4. It's very important to distribute the cargo so it is:
as high up as possible.
piled up.
as low as possible.
in the centre of the load.
5. When checking air brakes on combination vehicles, which of the following is NOT part of checking that air flows to all trailers?
Using the trailer handbrake to provide air to the service line.
Going to the rear of the rig.
Pulling tractor forward until the fifth-wheel comes out from under the trailer.
Opening the emergency line shut-off valve at the rear of the last trailer.
6. What happens when the center of gravity of a truck moves higher up from the road?
The vehicle is more stable while turning.
It becomes much easier to downshift at the right rpm.
The truck becomes easier to turn over.
It is easier it is to turn around corners.
7. To prevent a rollover, the driver should:
make quick lane changes if possible.
drive on the shoulder if possible.
drive slowly around corners, on ramps, and off ramps.
pay extra attention to the coolant level.
8. If you try to couple when the trailer is too low:
the tractor may strike and damage the trailer nose.
it might not couple correctly.
the tractor could roll away.
All of the above.
9. The trailer hand valve should:
be used in driving.
never be used to test the trailer brakes.
never be used for parking.
All of the above.
10. To secure the tractor you should:
Put on the parking brake and put the transmission in neutral.
Check that the kingpin and the fifth-wheel are aligned.
Connect the tractor service air-line to the trailer service glad hand.
All of the above.
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NC Combination Test

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