Should only be used to test trailer brakes.

Should be used when parking uphill.

Be sure that you are coupling correctly.

You can assume all vehicles are the same.

Cracks in the mounting are acceptable.

Oklahoma CDL Combination 2 - DMV Written Test Questions with Answers

Q.1

What is a bobtail tractor?

A tractor without a trailer
A tractor attached to two trailers
A tractor with a tank

Q.2

If a trailer begins to jackknife, the driver:

Should not apply the trailer hand brake.
Should firmly apply the brakes.
Can straighten the trailer with the parking brake.

Q.3

Combination vehicles:

Are usually shorter than single commercial vehicles.
Usually require less skill to drive than single commercial vehicles.
Usually require more skill to drive than single commercial vehicles.

Q.4

Before a trip, you can make sure air flows to all trailers by:

Checking for moving air inside of each trailer.
Listening for air at the rear shut-off valve.
Feeling for air at the front shut-off valve.

Q.5

If a load is placed on one side of a trailer, the trailer:

May lean during turns.
May add extra support during turns.
May be easier to steer during turns.

Q.6

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.7

Before beginning a trip, you should:

Leave the service line valve open.
Remove the relay valves.
Close the emergency line valve.

Q.8

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

Relay
Supply
Emergency

Q.9

When driving with trailers, you should:

Make quick, sudden changes.
Avoid making sudden moves.
Accelerate by pushing the accelerator to the floor.

Q.10

A trolley valve:

Should be used while driving.
Should only be used to test trailer brakes.
Should be used when parking uphill.

Q.11

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

Lightest
Heaviest
Smallest

Q.12

To help prevent a rollover, cargo should be:

Placed as high as possible inside a trailer.
Placed as low as possible inside a trailer.
Placed on the driver’s side of a trailer.

Q.13

When braking with ABS, you should:

Push the brake pedal harder than usual.
Push the brake pedal as you normally would.
Push the brake pedal more lightly than usual.

Q.14

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.

Q.15

During a trip, the ____ should be open.

Rear service line shut-off valve
Rear supply line shut-off valve
Inner shut-off valves

Q.16

Combination vehicles are usually:

Easier to drive than single commercial vehicles.
Lighter than single commercial vehicles.
More difficult to drive than single commercial vehicles.

Q.17

If you are backing and the trailer begins to drift off-course, the driver should:

Return the steering wheel to the 12 o’clock position.
Turn the top of the steering wheel in the direction of the drift.
Turn the top of the steering wheel in the direction opposite of the drift.

Q.18

When coupling:

You can assume all vehicles are the same.
Be sure that you are coupling correctly.
Cracks in the mounting are acceptable.

Q.19

The best way to recognize that your trailer has started to skid is by:

Seeing other drivers' faces.
Checking the trailer in your mirrors.
Feeling the trailer move.

Q.20

The trailer hand valve should be used:

To test the trailer brakes.
To check the connection between the trailer and tractor.
To accelerate.