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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. A vehicle inspection should be done in the same order each time:
so you are less likely to forget something.
because it is required by law.
because the report must be written in that order.
2. When backing a trailer, turn the wheel right to make the cab go ________ and the trailer go ________.
left; right
left; left
right; left
3. The emergency air line does NOT:
pump air into the relay valves, allowing the trailer brakes to be applied more quickly.
control the emergency brakes on combination vehicles.
supply air to the trailer air tanks.
4. What is the emergency air line for?
It controls theĀ front brakes of the tractor in case of an emergency.
It supplies air to the trailer air tanks, and controls the emergency brakes on combination vehicles.
It tells you the amount of brake pressure you need to stop the vehicle.
5. Combination vehicles usually:
are shorter than single than single CMVs.
require more driving skill than single CMVs.
are easier to drive than single than single CMVs.
6. If your vehicle thumps or vibrates heavily, it may be a sign that:
the brakes have failed.
you need to shift up.
one of the tires has gone flat.
7. Which of the following will NOT help you prevent rollover?
Keeping the cargo as close to the ground as possible.
Driving slowly around turns.
Using the controlled braking method.
8. When backing a truck you should:
get out and walk around the vehicle before you begin to back.
look straight ahead.
always rely on your mirrors.
9. If the drive wheels start to skid:
use the brakes to slow down.
push in the clutch to let them turn freely.
accelerate slightly to regain control.
10. Which of the following is not a reason for covering cargo?
To protect people from spilled cargo
To protect the cargo from weather
To prevent other drivers from looking at the cargo
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IA CDL Combination Test

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