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Pennsylvania CDL Combination Test 1
Practice mode
Question
1
of 20
QUESTION 1 / 20
What does the trailer air supply control look like?
Choose one answer below.
A
It is a square blue knob.
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B
It is a triangular yellow knob.
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C
It is an eight-sided red knob.
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D
It is a circular orange knob.
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QUESTION 2 / 20
In a vehicle equipped with an automatic tractor protection valve, the valve will pop out when:
Choose one answer below.
A
Air pressure drops to a level between 20 and 45 psi.
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B
You are experiencing a trailer jackknife.
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C
Wheels have regained traction after a skid.
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D
Air pressure is above 45 psi.
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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
When driving a bobtail tractor, you should be aware that:
Choose one answer below.
A
Bobtails stop very easily.
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B
Bobtails cannot drive as fast as tractors with semitrailers.
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C
Bobtails are more difficult to stop than tractors with semitrailers.
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D
Bobtails are illegal in most states.
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QUESTION 5 / 20
When a combination vehicle goes around a corner:
Choose one answer below.
A
The turn should be made as tightly as possible.
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B
The front and rear wheels move in different paths.
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C
The rear wheels should run over the curb.
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D
It is acceptable for street signs to be knocked over if they are too close to the road.
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QUESTION 6 / 20
When connecting a converter dolly to a second or third trailer, the trailer height should be:
Choose one answer below.
A
Slightly higher than the center of the fifth wheel.
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B
Level with the center of the fifth wheel.
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C
Slightly lower than the center of the fifth wheel.
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D
Next to the center of the fifth wheel.
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QUESTION 7 / 20
If a trailer is too high:
Choose one answer below.
A
It will not make a difference when coupling.
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B
It may not couple correctly.
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C
Coupling will be more secure.
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D
Coupling will be easier.
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QUESTION 8 / 20
Rollovers happen when:
Choose one answer below.
A
A truck driver is driving too fast.
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B
The driver of a vehicle in front of a truck is moving to slowly.
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C
A truck driver is driving too slowly.
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D
ABS is working effectively.
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QUESTION 9 / 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 10 / 20
Air pressure in the ____ air line is controlled by either the foot brake or trailer hand brake.
Choose one answer below.
A
Emergency
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B
Service
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C
Rear
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D
Auxiliary
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QUESTION 11 / 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 12 / 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 13 / 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 14 / 20
A combination vehicle has:
Choose one answer below.
A
One air line.
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B
Two air lines.
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C
Three air lines.
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D
Four air lines.
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QUESTION 15 / 20
Driving a combination vehicle ____ than driving a single vehicle.
Choose one answer below.
A
Is easier
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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 16 / 20
An Anti-Lock Braking System (ABS):
Choose one answer below.
A
Allows wheels to lock up.
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B
Prevents wheels from locking up.
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C
Makes it easier to turn a large vehicle.
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D
Assists with the operation of brake lights.
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QUESTION 17 / 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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QUESTION 18 / 20
Push in the trailer air supply control to:
Choose one answer below.
A
Activate the emergency brakes.
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B
Deactivate the air brakes.
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C
Sound the horn.
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D
Supply the trailer with air.
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QUESTION 19 / 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 20 / 20
After finishing a pre-trip inspection, you should:
Choose one answer below.
A
Leave the rear shut-off valves open.
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B
Remove the service line valve.
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C
Close the emergency line valve.
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D
Leave the emergency line valve open.
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