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Texas CDL Combination Test 1
Practice mode
Question
1
of 20
QUESTION 1 / 20
Driving a combination vehicle ____ than driving a single vehicle.
Choose one answer below.
A
Is easier
✓
B
Requires more driving skill
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C
Is better for training
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D
Is safer in inclement weather
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QUESTION 2 / 20
The easiest way to recognize that your trailer has begun to skid is to:
Choose one answer below.
A
Ask another driver.
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B
Use your mirrors to determine if the trailer has left the lane.
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C
Release the brake pedal and then push it down again.
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D
Watch the jackknife warning light on the control panel.
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QUESTION 3 / 20
When coupling a trailer:
Choose one answer below.
A
Make sure to couple matching glad hands.
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B
Any glad hand can be connected to any other glad hand.
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C
It is best to leave one glad hand unattached.
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D
Only one set of glad hands should be connected.
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QUESTION 4 / 20
The trailer hand valve:
Choose one answer below.
A
Should always be used for parking.
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B
Should only be used for parking on a downhill.
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C
Should never be used for parking.
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D
Should only be used when transporting cargo.
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QUESTION 5 / 20
Using the trailer hand valve while driving:
Choose one answer below.
A
Will help you turn safely.
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B
Will stop your trailer safely.
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C
Can cause a skid.
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D
Is impossible.
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QUESTION 6 / 20
An air supply control in its "emergency" position will:
Choose one answer below.
A
Turn on the air supply.
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B
Apply the trailer emergency brakes.
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C
Prevent a skid.
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D
Accelerate the vehicle.
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QUESTION 7 / 20
Which type of vehicle is most prone to the “crack-the-whip” effect?
Choose one answer below.
A
A five-axle tractor semi-trailer
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B
A three-axle tractor semi-trailer
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C
A bobtail tractor
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D
A triple trailer
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QUESTION 8 / 20
Before a drive, ensure that air flows to all trailers by:
Choose one answer below.
A
Opening the rear shut-off valves and listening for escaping air.
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B
Closing the rear shut-off valves and listening for escaping air.
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C
Disconnecting air supply lines and listening for escaping air.
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D
Rolling each trailer down a hill and testing the brakes.
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QUESTION 9 / 20
The service air line is attached to the:
Choose one answer below.
A
Relay valves.
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B
Supply line.
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C
Emergency air line.
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D
Steering wheel.
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QUESTION 10 / 20
Trailers with low underneath clearance may be difficult to drive:
Choose one answer below.
A
On interstate highways.
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B
Over railroad crossings.
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C
On dirt roads.
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D
At the posted speed limit.
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QUESTION 11 / 20
When entering or crossing traffic while driving a combination vehicle, it is especially important that you:
Choose one answer below.
A
Sound your horn.
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B
Make sure there is a large enough gap for your vehicle.
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C
Expect other drivers to make room for your vehicle.
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D
Let other drivers wave you into their lane.
✓
QUESTION 12 / 20
Large combination vehicles take the longest amount of time to stop:
Choose one answer below.
A
When fully loaded.
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B
When partially loaded.
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C
When empty.
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D
When mostly loaded.
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QUESTION 13 / 20
A lightly-loaded combination vehicle will stop more slowly than a fully-loaded vehicle because:
Choose one answer below.
A
The stiff suspension springs and strong brakes will have high traction.
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B
The stiff suspension springs and strong brakes will have low traction.
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C
The brakes only operate when a trailer reaches a minimum weight.
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D
The suspension springs only operate when a trailer reaches a minimum weight.
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QUESTION 14 / 20
Fully-loaded rigs:
Choose one answer below.
A
Are less likely to roll over than empty rigs.
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B
Are more likely to roll over than empty rigs.
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C
Are just as likely to roll over as empty rigs.
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D
Should not be driven.
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QUESTION 15 / 20
One way to prevent a rollover is to:
Choose one answer below.
A
Move cargo to the left side of the rig.
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B
Keep cargo centered on the rig.
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C
Move cargo to the right side of the rig.
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D
Keep cargo as far from the ground as possible.
✓
QUESTION 16 / 20
The trailer hand valve should be used:
Choose one answer below.
A
To test the trailer brakes.
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B
To check the connection between the trailer and tractor.
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C
To accelerate.
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D
To test the lights on the trailer.
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QUESTION 17 / 20
A shut-off valve:
Choose one answer below.
A
Is located on the front of a trailer.
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B
Is located on the instrument panel.
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C
Prevents air from escaping an air brake system.
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D
Should always be open.
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QUESTION 18 / 20
Failure to keep the fifth wheel plate properly greased could:
Choose one answer below.
A
Cause the trailer to disconnect.
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B
Cause steering problems.
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C
Cause braking problems.
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D
Affect the lights.
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QUESTION 19 / 20
A tractor protection valve is:
Choose one answer below.
A
A device that keeps air in the tractor or truck brake system, should the trailer break away or develop a bad leak.
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B
A device that prevents theft.
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C
A device that controls fuel levels.
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D
A device that allows the battery to recharge efficiently.
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QUESTION 20 / 20
A trailer will be most likely to swing around when:
Choose one answer below.
A
It is full.
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B
Traveling in a straight line.
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C
It is empty.
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D
The wheels are rotating.
✓
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