Prevents air from escaping an air brake system.

Is located on the front of a trailer.

Is located on the instrument panel.

Are more likely to roll over than empty rigs.

Are less likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

Alabama CDL Combination 2 - DMV Written Test Questions with Answers

Q.1

The service air line is often controlled by the foot brake and is attached to the ____ valves.

Relay
Supply
Emergency

Q.2

When coupling, after you've connected the air lines to the trailer, you should:

Supply air to the trailer.
Activate the emergency brake.
Disconnect the glad hands.

Q.3

While inspecting a coupling, you should go under the trailer and:

Detach the jaws from around the kingpin.
Make sure the locking lever is in the "emergency" position.
Remove the safety latch.
Look into the back of the fifth wheel.

Q.4

In a sudden turn, the ____ trailer is the most likely to turn over.

Front
Last
Middle
First

Q.5

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.

Q.6

A loss of air pressure in the emergency line will cause:

The suspension springs to extend.
The tractor protection valve to open.
The rear trailer to detach from the combination.
The emergency brakes to activate.

Q.7

In a double or triple combination, the ____ trailer should be directly behind the cab.

Lightest
Heaviest
Smallest

Q.8

When driving a vehicle equipped with an Anti-Lock Braking System (ABS), brakes should be applied:

In the same way as they would be in a vehicle without ABS.
As the vehicle is placed in neutral.
With the hand brake.

Q.9

In a vehicle equipped with an automatic tractor protection valve, the valve will pop out when air pressure drops to a level between:

20 and 45 psi.
75 and 105 psi.
50 and 65 psi.

Q.10

Proper coupling technique:

Is the same on all vehicles.
Is essential to the safe operation of a vehicle.
Includes ensuring that the fifth wheel plate is not greased.
Can be learned over time.

Q.11

A shut-off valve:

Is located on the front of a trailer.
Is located on the instrument panel.
Prevents air from escaping an air brake system.
Should always be open.

Q.12

If you must cross traffic while driving a combination vehicle, you should:

Assume other drivers will make room for your vehicle.
Wait for a gap large enough for your vehicle to safely cross.
Rely only on your mirrors.

Q.13

If your vehicle gets stuck on railroad tracks, you should:

Sit in the cab and call for help.
Exit the cab and walk away from the tracks.
Motion for another driver to push your vehicle.

Q.14

If your trailer goes off course while you are backing, you should:

Continue the backing process without changing anything.
Pull the truck forward, readjust, and start backing again.
Get out of the truck and move the trailer into the right position.
Turn the steering wheel all the way to the left until the trailer straightens out.

Q.15

In a vehicle equipped with an automatic tractor protection valve, the valve will pop out when:

Air pressure drops to a level between 20 and 45 psi.
You are experiencing a trailer jackknife.
Wheels have regained traction after a skid.
Air pressure is above 45 psi.

Q.16

The ____ trailer is the most likely to turn over if a driver takes a turn too quickly.

Front
Last
Middle

Q.17

After coupling, there should be ____ between the upper and lower fifth wheel.

No space
Very little space
A lot of space
Three inches of space

Q.18

Fully-loaded rigs:

Are less likely to roll over than empty rigs.
Are more likely to roll over than empty rigs.
Are just as likely to roll over as empty rigs.
Should not be driven.

Q.19

Push in the trailer air supply control to:

Activate the emergency brakes.
Deactivate the air brakes.
Sound the horn.
Supply the trailer with air.

Q.20

To lower the risk of a rollover, you should:

Load the cargo as far forward as possible.
Load the cargo as far back as possible.
Load the cargo as low as possible.
Stack the cargo as high as possible.