Instructions

Combination

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Alaska Commercial Driver License.. Read More

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Alaska Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice questions, and applicants will need to correctly answer a minimum of 16 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

1. When coupling, you should:

Make sure to couple the proper glad hands.

Only couple one set of glad hands.

It is best to leave one glad hand loose.

When coupling air brake hoses, you should make sure the proper pairs of gland hands are connected. They are sometimes color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

2. In an empty combination vehicle, the stiff suspension springs and strong brakes will have:

High traction.

Low traction.

No traction.

An empty combination vehicle will come to a complete stop more slowly than a fully-loaded vehicle. With less weight in a trailer, the stiff suspension springs and strong brakes will have lower traction than they would if the vehicle carried more weight.

3. Rearward amplification refers to:

The amount of noise projected to the rear of the vehicle.

The cause of the "crack-the-whip" effect.

The number of trailers that can be pulled by one tractor.

The "crack-the-whip" effect is a result of rearward amplification. If not properly handled, a trailer can tip over due to rearward amplification.

4. What does an Anti-Lock Braking System (ABS) do?

It allows a vehicle's wheels to lock up.

It prevents a vehicle's wheels from locking up.

It makes turning a vehicle easier.

An Anti-Lock Braking System (ABS) helps prevent wheel lockup during hard braking. If ABS detects impending lockup, it reduces braking pressure to a safe level.

5. If the emergency air line loses pressure:

The Anti-Lock Braking System will activate.

The service air line will activate.

The emergency brakes will activate.

The emergency air line controls the emergency brakes on a combination vehicle. A loss of air pressure in the emergency line will cause the emergency trailer brakes to activate.

6. When coupling a trailer:

Make sure to couple the proper glad hands.

Glad hands can be connected to any other glad hands.

Only one set of glad hands should be connected.

When coupling, make sure you couple matching glad hands. They are often color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

7. Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:

The trailer will stop normally.

The trailer will not have brakes.

The trailer will speed up.

Older trailers do not have spring brakes. This means that if the air supply in an older trailer's air tank has leaked away, there will be no working brakes connected to the trailer and its wheels will turn freely.

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