District of Columbia CDL Combination 1 - DMV Written Test Questions with Answers - MCQGeeks.com

Q.1

Failure to keep the fifth wheel plate properly greased could:

Cause the trailer to disconnect.
Cause steering problems.
Cause braking problems.
Affect the lights.

Q.2

If a parked trailer does not have spring brakes, you should keep the trailer from moving by:

Using the air brakes.
Using wheel chocks.
Parking near a wall.
Parking on a slight incline.

Q.3

A combination vehicle has:

One air line.
Two air lines.
Three air lines.
Four air lines.

Q.4

Avoid needing to make sudden lane changes by:

Using your horn to encourage other drivers to move out of your lane.
Only driving slower than the posted speed limit.
Watching the road ahead while driving.
Pulling off the road and waiting when there is high traffic.

Q.5

During a trip, which shut-off valves should be open?

All shut-off valves should be open.
The rear shut-off valves should be open.
All shut-off valves should be in the open position, except the rear shut-off valves.
No shut-off valves should be open.

Q.6

In a combination rig, it is best to make:

Quick, sudden stops.
Sharp turns.
Quick accelerations.
Slow, planned stops.

Q.7

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

May lean, and could result in a rollover.
May add extra support during turns.
Have improved braking.
Have improved steering.

Q.8

To prevent a trailer from rolling over, you should:

Speed up when nearing a corner.
Make sudden steering moves.
Take on-ramps faster than the posted speed limit.
Drive slowly around corners.

Q.9

When the wheels of a trailer lock up:

The trailer will stay straight.
The trailer tends to swing around.
The cab will swing, but the trailer will stay straight.
They will likely go flat.

Q.10

If unsure if a trailer is equipped with ABS, you can:

Check under the trailer for wheel speed sensors coming from the back of the brakes.
Try driving on a slippery surface and see if ABS kicks in.
Assume it does have ABS.
Remove a tire and look for the ABS sensor on the axle.

Q.11

Which of the following types of vehicles is most prone to the “crack-the-whip" effect?

An automobile
A three-axle tractor
A bobtail tractor
A triple combination

Q.12

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.13

Using the trailer hand brake while experiencing a trailer jackknife will:

Stop the skid.
Straighten the trailer.
Increase traction.
Continue the skid.

Q.14

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

Front
Last
Middle
First

Q.15

When driving a tractor-trailer equipped with ABS, you should:

Stop harder than you would otherwise.
Use extra braking force to ensure the ABS kicks in.
Brake as you normally would.
Brake using less pressure than you would otherwise use.

Q.16

If colors are being used to distinguish glad hands, which color is used for emergency lines?

Orange
Yellow
Blue
Red

Q.17

A tractor protection valve is:

A device that keeps air in the tractor or truck brake system, should the trailer break away or develop a bad leak.
A device that prevents theft.
A device that controls fuel levels.
A device that allows the battery to recharge efficiently.

Q.18

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.19

Simply changing lanes can cause:

A “crack-the-whip” effect, resulting in a rollover.
A trailer to straighten out.
Confusion over which lane the driver is hoping to use.
Other drivers to reduce their speed.

Q.20

When driving a combination rig, following distance should be:

Decreased in poor weather.
Shorter than when driving a single vehicle.
About the same as when driving a single vehicle.
Longer than when driving a single vehicle.

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