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LA CDL Combination Practice Questions - Louisiana CDL Combination Vehicles Test Exam
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Question
1
of 25
QUESTION 1 / 25
Who needs the Louisiana CDL Combination Vehicles knowledge test?
Choose one answer below.
A
A driver seeking Class A combination-vehicle privileges
✓
B
Any Class E personal-license applicant
✓
C
Only drivers hauling hazardous materials
✓
D
Only drivers pulling double or triple trailers
✓
QUESTION 2 / 25
Under federal Class A CDL rules used by Louisiana, the towed unit must be over what rating when the combination is 26,001 pounds or more?
Choose one answer below.
A
5,000 pounds GVWR
✓
B
10,000 pounds GVWR or GVW
✓
C
8,000 pounds GVWR
✓
D
26,001 pounds GVWR
✓
QUESTION 3 / 25
What score is required to pass a CDL knowledge test under 49 CFR 383.135?
Choose one answer below.
A
At least 60 percent correct
✓
B
At least 70 percent correct
✓
C
At least 80 percent correct
✓
D
A perfect 100 percent score
✓
QUESTION 4 / 25
What is a combination vehicle?
Choose one answer below.
A
A single straight truck
✓
B
Any vehicle with air brakes
✓
C
A bus used for passengers only
✓
D
A truck or tractor pulling one or more trailers
✓
QUESTION 5 / 25
What is off-tracking?
Choose one answer below.
A
The trailer rear wheels follow a shorter inside path than the tractor front wheels
✓
B
The tractor loses engine power
✓
C
The fifth wheel slides by itself
✓
D
The trailer electrical cord disconnects
✓
QUESTION 6 / 25
Why drive deeper into an intersection before a right turn?
Choose one answer below.
A
To make the kingpin lock tighter
✓
B
To let trailer wheels clear curbs and fixed objects
✓
C
To avoid checking mirrors
✓
D
To cool the trailer brakes
✓
QUESTION 7 / 25
What is the trailer kingpin?
Choose one answer below.
A
The red trailer air-supply knob
✓
B
The landing gear crank
✓
C
The vertical pin that locks into the fifth wheel jaws
✓
D
The trailer ABS lamp
✓
QUESTION 8 / 25
What should fifth wheel jaws do after proper coupling?
Choose one answer below.
A
Stay open until the first stop
✓
B
Clamp the landing gear
✓
C
Lock only the electrical cord
✓
D
Close and lock around the kingpin
✓
QUESTION 9 / 25
What color identifies the trailer emergency or supply glad hand?
Choose one answer below.
A
Red
✓
B
Blue
✓
C
Green
✓
D
Yellow
✓
QUESTION 10 / 25
What color identifies the trailer service glad hand?
Choose one answer below.
A
Red
✓
B
Blue
✓
C
Black
✓
D
White
✓
QUESTION 11 / 25
What is the electrical line between tractor and trailer for?
Choose one answer below.
A
Charging trailer air tanks
✓
B
Holding up the landing gear
✓
C
Trailer lights and electrical equipment
✓
D
Mechanically locking the fifth wheel
✓
QUESTION 12 / 25
What does the trailer hand valve control?
Choose one answer below.
A
Only steering axle brakes
✓
B
Only trailer lights
✓
C
The fifth wheel release
✓
D
Only the trailer service brakes
✓
QUESTION 13 / 25
Why not use the trailer hand valve for parking?
Choose one answer below.
A
Air can leak away and release service brakes
✓
B
It lowers the landing gear
✓
C
It disconnects glad hands
✓
D
It locks the steering axle
✓
QUESTION 14 / 25
What is a coupling tug test?
Choose one answer below.
A
Drive at highway speed and brake
✓
B
Set trailer brakes and gently pull forward to confirm the kingpin is locked
✓
C
Pull the electrical cord
✓
D
Raise landing gear before looking under the trailer
✓
QUESTION 15 / 25
After a successful tug test, what check is still needed?
Choose one answer below.
A
No other check is needed
✓
B
Release the fifth wheel handle
✓
C
A visual check of locked jaws and no gap
✓
D
Drive before connecting lines
✓
QUESTION 16 / 25
What is the safest general backing rule?
Choose one answer below.
A
Back quickly for momentum
✓
B
Use the trailer hand valve to steer
✓
C
Avoid mirrors
✓
D
Back slowly and get out to look as needed
✓
QUESTION 17 / 25
Which backing direction is preferred when available?
Choose one answer below.
A
Driver-side backing
✓
B
Blind-side backing
✓
C
Backing without mirrors
✓
D
Backing from the sharpest angle
✓
QUESTION 18 / 25
What is a jackknife?
Choose one answer below.
A
The landing gear collapses
✓
B
The tractor and trailer fold sharply toward each other
✓
C
The fifth wheel plate is dry
✓
D
The cargo doors open
✓
QUESTION 19 / 25
If a trailer skid starts from locked wheels, what should you do first?
Choose one answer below.
A
Apply more trailer hand valve
✓
B
Accelerate hard
✓
C
Release the brakes so the wheels can roll
✓
D
Set parking brakes
✓
QUESTION 20 / 25
Why do empty trailers lock wheels more easily?
Choose one answer below.
A
Their brakes are disconnected
✓
B
They have no suspension
✓
C
Their ABS is always disabled
✓
D
Less weight presses the tires onto the road
✓
QUESTION 21 / 25
How do you reduce rollover risk in curves?
Choose one answer below.
A
Slow down before curves and turns
✓
B
Steer sharply at the last second
✓
C
Use the trailer hand valve in the curve
✓
D
Load cargo as high as possible
✓
QUESTION 22 / 25
How should cargo be loaded to reduce rollover risk?
Choose one answer below.
A
High and to one side
✓
B
Low, centered, balanced, and secured
✓
C
Loose so it can settle
✓
D
All behind the rear axle
✓
QUESTION 23 / 25
What should landing gear condition show for travel?
Choose one answer below.
A
Halfway down for stability
✓
B
Used instead of trailer brakes
✓
C
Fully raised with crank handle secured
✓
D
Disconnected from the frame
✓
QUESTION 24 / 25
How should air and electrical lines be routed after coupling?
Choose one answer below.
A
Dragging to prove length
✓
B
Red and blue crossed
✓
C
Disconnected until after the first turn
✓
D
Correctly connected with slack, not dragging or pinched
✓
QUESTION 25 / 25
What does a trailer ABS warning lamp mean?
Choose one answer below.
A
ABS may be disabled and repair is needed, while regular brakes still need checking
✓
B
All brakes are gone every time
✓
C
The trailer air tanks are full
✓
D
The fifth wheel unlocked
✓
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