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OR CDL Combination Practice Questions - Oregon CDL Combination Vehicles Test Exam
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Question
1
of 25
QUESTION 1 / 25
Under Oregon CDL rules, the Combination Vehicles Test is required for drivers seeking to operate which vehicles?
Choose one answer below.
A
Only passenger buses
✓
B
Class A combination vehicles
✓
C
Only tank vehicles
✓
D
Motorcycles with trailers
✓
QUESTION 2 / 25
A Group A/Class A combination generally means a combination with a GCWR of at least 26,001 pounds and a towed unit over:
Choose one answer below.
A
5,000 pounds
✓
B
8,000 pounds
✓
C
10,000 pounds
✓
D
20,000 pounds
✓
QUESTION 3 / 25
What is the best way to reduce rollover risk in a loaded combination vehicle?
Choose one answer below.
A
Keep cargo high and drive normally
✓
B
Keep cargo low and slow before turns
✓
C
Brake hard while turning
✓
D
Use the trailer hand valve through curves
✓
QUESTION 4 / 25
The “crack-the-whip” effect is mainly caused by:
Choose one answer below.
A
Rearward amplification after quick steering
✓
B
Too much fifth-wheel grease
✓
C
Low engine coolant
✓
D
A trailer door left open
✓
QUESTION 5 / 25
Oregon Section 6 recommends following at least one second for each 10 feet of vehicle length, plus one extra second when traveling over:
Choose one answer below.
A
25 mph
✓
B
35 mph
✓
C
40 mph
✓
D
55 mph
✓
QUESTION 6 / 25
What is off-tracking?
Choose one answer below.
A
The trailer wheels follow a shorter path than the tractor in a turn
✓
B
The tractor engine loses power uphill
✓
C
The air lines disconnect during backing
✓
D
The fifth wheel slides forward by itself
✓
QUESTION 7 / 25
When making a right turn with a tractor-trailer, you should mainly watch for:
Choose one answer below.
A
The trailer cutting inside the tractor path
✓
B
The trailer turning wider than the tractor
✓
C
The kingpin unlocking automatically
✓
D
The service line changing color
✓
QUESTION 8 / 25
During a left turn in a combination vehicle, why should you monitor the left side carefully?
Choose one answer below.
A
Cars or motorcycles may try to pass on the left
✓
B
The trailer air tank may overfill
✓
C
The landing gear lowers in left turns
✓
D
The fifth wheel must be unlocked
✓
QUESTION 9 / 25
Before entering a sharp curve with a heavy combination, the safest approach is to:
Choose one answer below.
A
Slow to a safe speed before the curve
✓
B
Maintain speed and brake in the curve
✓
C
Accelerate to keep the trailer straight
✓
D
Use only the trailer brakes
✓
QUESTION 10 / 25
Which backing setup is generally preferred for a combination vehicle when available?
Choose one answer below.
A
Blind-side backing
✓
B
Driver-side backing
✓
C
Backing from the passenger seat
✓
D
Backing without checking mirrors
✓
QUESTION 11 / 25
A trailer skid is most often corrected by:
Choose one answer below.
A
Releasing the brakes so trailer wheels roll
✓
B
Applying only the trailer hand valve
✓
C
Steering harder away from the skid
✓
D
Pulling the parking brake
✓
QUESTION 12 / 25
What is a jackknife?
Choose one answer below.
A
The tractor and trailer fold toward each other at the coupling
✓
B
A loose landing-gear crank
✓
C
A broken trailer light circuit
✓
D
A normal fifth-wheel adjustment
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QUESTION 13 / 25
The kingpin is:
Choose one answer below.
A
The vertical trailer pin that locks into the fifth wheel jaws
✓
B
The red trailer air supply knob
✓
C
The landing gear crank handle
✓
D
The electrical socket on the tractor
✓
QUESTION 14 / 25
Before backing under a trailer to couple, the fifth-wheel locking jaws should be:
Choose one answer below.
A
Open
✓
B
Closed and locked
✓
C
Removed
✓
D
Covered by the release handle
✓
QUESTION 15 / 25
For coupling, the trailer should be set so the tractor must:
Choose one answer below.
A
Lift the trailer slightly as it backs under
✓
B
Pass under with no contact at all
✓
C
Hit the trailer hard to latch
✓
D
Stay several inches below the apron
✓
QUESTION 16 / 25
A tug test is performed by:
Choose one answer below.
A
Setting trailer brakes and gently pulling forward in low gear
✓
B
Driving at highway speed and braking hard
✓
C
Lowering the landing gear while moving
✓
D
Disconnecting the electrical cord
✓
QUESTION 17 / 25
After a tug test, what visual check is still required?
Choose one answer below.
A
Jaws closed around the kingpin shank and no gap between fifth wheel and apron
✓
B
Fuel cap color
✓
C
Cab radio operation
✓
D
Windshield washer level only
✓
QUESTION 18 / 25
Which line is the emergency or supply line on most tractor-trailers?
Choose one answer below.
A
Red
✓
B
Blue
✓
C
Green
✓
D
White
✓
QUESTION 19 / 25
Which line carries service-brake control pressure to the trailer?
Choose one answer below.
A
Red emergency line
✓
B
Blue service line
✓
C
Electrical light cord
✓
D
Landing-gear air hose
✓
QUESTION 20 / 25
The trailer electrical cord should be:
Choose one answer below.
A
Firmly plugged in and secured
✓
B
Left loose for more slack
✓
C
Disconnected during highway travel
✓
D
Wrapped around the landing gear
✓
QUESTION 21 / 25
Before driving after coupling, landing gear should be:
Choose one answer below.
A
Fully raised with the crank handle secured
✓
B
Left partly down for support
✓
C
Lowered until it touches the road
✓
D
Removed from the trailer
✓
QUESTION 22 / 25
When parking a trailer for uncoupling, what surface is best?
Choose one answer below.
A
Firm, level ground
✓
B
Soft mud
✓
C
A steep downgrade
✓
D
A traffic lane
✓
QUESTION 23 / 25
The trailer hand valve should normally be used for:
Choose one answer below.
A
Testing trailer brakes, not normal stopping
✓
B
Parking overnight
✓
C
Controlling speed on every hill
✓
D
Replacing the foot brake
✓
QUESTION 24 / 25
To supply air to the trailer after coupling, the driver normally:
Choose one answer below.
A
Pushes in the red trailer air supply knob
✓
B
Pulls out the yellow parking brake knob only
✓
C
Unplugs the blue service line
✓
D
Lowers the landing gear
✓
QUESTION 25 / 25
Which item belongs in the coupling-area inspection?
Choose one answer below.
A
Fifth-wheel mounting, jaws, kingpin, air/electric lines
✓
B
Only the engine oil dipstick
✓
C
Only the cab heater
✓
D
Only the windshield wipers
✓
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