Virginia DMV CDL General Knowledge Practice Test 4
Test 4 of 5. Pick an answer for each question to see if it is right and why; your score appears at the end. You need 40 correct answers to pass, the same ratio as the real Virginia test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. You are moving an oversized load under a permit that requires a pilot vehicle. What is the pilot vehicle there to do?
Show answer
Answer B: Warn other traffic and check the route ahead for clearances and hazards
Escort or pilot vehicles warn approaching traffic and scout the route for low bridges, narrow spots and other hazards that a wide or long load cannot pass.
-
2. How long must a Virginia commercial learner's permit be held before the CDL skills test?
Show answer
Answer B: A minimum of 14 days
Virginia requires an applicant who has never held a CDL to obtain and hold a commercial learner's permit for a minimum of 14 days.
-
3. How should speed and gears be handled when approaching a curve?
Show answer
Answer A: Slow to a safe speed and downshift before entering the curve
Braking and shifting are completed before the curve so the vehicle is settled and can pull gently through it without upsetting the load.
-
4. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
Show answer
Answer C: After 8 cumulative hours of driving time
Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.
-
5. You normally pull an empty trailer, but today the same tractor is loaded to its legal maximum. What changes about getting under way?
Show answer
Answer A: You may need to start in a lower gear, since the load takes more pulling power
The heavier the load, the lower the gear needed to get the vehicle rolling without lugging or stalling the engine.
-
6. On the Interstate System, what is the federal maximum weight allowed on a single axle?
Show answer
Answer A: 20,000 pounds
Federal limits for the Interstate System cap one single axle at 20,000 pounds.
-
7. How often must every commercial motor vehicle receive a periodic inspection?
Show answer
Answer C: At least once every twelve months
Federal rules require each commercial motor vehicle to pass a periodic inspection at least once in every twelve month period.
-
8. What must be checked on a sliding fifth wheel during the inspection?
Show answer
Answer B: That it is locked in position and not so far forward that the trailer can hit the cab
A slider that is unlocked can move under braking, and one set too far forward lets the trailer strike the cab when the tractor turns sharply.
-
9. A car that passed you on the right slows and stays alongside your trailer. What is the best response?
Show answer
Answer D: Ease off the accelerator so the car can move clear
A vehicle sitting beside a trailer is in a blind area and has nowhere to go if you need the lane, so the safest fix is to let it get ahead or behind.
-
10. Under the federal air brake standard, the low air pressure warning must come on before reservoir pressure drops below what level?
Show answer
Answer A: Before pressure falls below 60 psi
Federal Motor Vehicle Safety Standard 121 requires the warning to operate while service reservoir pressure is still above 60 psi, which leaves enough air to bring the vehicle to a normal stop.
-
11. A hazard suddenly appears ahead and you must act. Which is usually the faster way to avoid it in a heavy vehicle?
Show answer
Answer B: Steering around it, because you can usually turn faster than you can stop
Stopping distance at speed is very long, so a quick turn out of the way, when there is room, avoids the crash sooner than braking.
-
12. How is a shipping container normally secured when it is carried on a special container chassis?
Show answer
Answer B: With its own locking devices that attach the container directly to the chassis frame
Containers built for rail or ship transport have locking corners that fasten to a matching chassis; a container carried on a plain flatbed must be secured like any other cargo.
-
13. An intermodal container is being carried on an ordinary flatbed rather than on a container chassis. What does that mean for securement?
Show answer
Answer B: It must be secured with tiedowns that meet the container securement requirements
A container carried on a vehicle that is not fitted with integral locking devices has to be secured to the deck with tiedowns that satisfy the rules for containers.
-
14. What should you look for on the electrical wiring in the engine compartment?
Show answer
Answer A: Worn, frayed or cracked insulation and loose or corroded connections
Damaged insulation can short a circuit against the frame or engine, which can kill a lamp you depend on or start a fire.
-
15. Where is a dunnage bag used and how does it work?
Show answer
Answer D: Between pieces of cargo inside a van, where it is inflated to take up the gap
A dunnage bag is placed in the void between loads and inflated so the cargo is wedged and cannot move as the vehicle rolls and brakes.
-
16. You pick up a sealed trailer at a shipper. What should you check before leaving the dock?
Show answer
Answer B: That the seal number matches the paperwork and that the doors are properly closed
You cannot look at a sealed load, but you can confirm that the seal is intact, that its number matches the documents and that the doors are secure.
-
17. You can see a crack in a brake drum that runs across more than half the width of the friction surface. What does this mean?
Show answer
Answer C: The drum is defective and must be repaired before the vehicle is driven
Cracks longer than half the width of the friction area mean the drum can break apart under braking heat and must be replaced.
-
18. Why should you never shift gears while crossing railroad tracks?
Show answer
Answer A: You could miss the gear or stall and be stuck on the tracks
A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.
-
19. What are you looking for when you check the drive belts in the engine compartment?
Show answer
Answer C: That each belt is snug and free of cracks, frays or heavy wear
A loose or cracked belt can break and stop the fan, the water pump or the alternator, which leads quickly to overheating or a dead electrical system.
-
20. What does it mean to overdrive your headlights at night?
Show answer
Answer D: Driving so fast that you cannot stop within the distance lit by your headlights
You must be able to stop inside the distance you can see; at night that distance is limited by the headlights, so speed must be lowered to match.
-
21. How do you test for leaks in a hydraulic brake system during the pre-trip inspection?
Show answer
Answer A: Pump the pedal three times, then hold firm pressure for five seconds and make sure the pedal does not move
If the pedal sinks while you hold pressure, fluid is escaping or air is in the lines, and the vehicle must not be driven until the problem is repaired.
-
22. In a vehicle with a manual transmission, when should the clutch be pushed in during a normal stop?
Show answer
Answer A: Just before the engine would stall, when the vehicle is nearly stopped
Staying in gear until the last moment keeps engine braking and steady control, so the clutch goes down only when the engine is about to drop below idle.
-
23. What is wrong with resting your foot on the clutch pedal between shifts?
Show answer
Answer B: It slowly wears the clutch out, because the pressure plate is never fully engaged
Any weight on the pedal partly disengages the clutch, so it slips and wears; the foot belongs off the pedal once the shift is finished.
-
24. A tire may be regrooved only when what is true?
Show answer
Answer B: It carries a marking from the manufacturer showing that it is regroovable
Only casings built with extra rubber under the tread and marked regroovable by the manufacturer may be cut, because others would be grooved into the belts.
-
25. Why does a driver use pull-ups while backing into a tight space?
Show answer
Answer C: To pull forward and start the approach again when the angle is going wrong
Stopping, pulling ahead and repositioning fixes a bad angle safely, and there is nothing wrong with needing more than one attempt.
-
26. Which brake lining condition must be reported?
Show answer
Answer C: Linings that are worn thin, loose, cracked or soaked with oil or grease
Linings must have enough material left and must be securely attached and clean, because a thin, loose or contaminated lining cannot deliver its share of braking.
-
27. Around a tractor-trailer, where are the blind areas that other drivers most often sit in unseen?
Show answer
Answer A: Along the right side and directly behind the trailer
The blind areas to the right of the cab and behind the trailer are the largest, which is why other drivers should never linger there.
-
28. You are the first to arrive at a crash. What is the correct order of actions?
Show answer
Answer C: Protect the area, notify the authorities, care for the injured
Preventing a second crash comes first, because an unprotected scene puts the injured and the helpers in more danger than the original collision.
-
29. An enforcement officer inspects your vehicle at the roadside and attaches an out-of-service sticker. What may you do?
Show answer
Answer C: Nothing until the defect is repaired; the vehicle may not be driven
An out-of-service order means the vehicle is unsafe, and no schedule, load or destination allows it to be driven before the defect is corrected.
-
30. Why is driving much slower than the rest of the traffic dangerous?
Show answer
Answer B: Other drivers must keep passing you, which creates conflicts
Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.
-
31. When a helper guides you while backing, what should be agreed on before you start?
Show answer
Answer D: A set of hand signals, especially the signal that means stop
The driver and helper must agree on signals in advance, above all the stop signal, because they usually cannot hear each other.
-
32. The car in the next lane still has snow covering most of its windows. What should you assume?
Show answer
Answer C: That driver cannot see you and may move into your lane
A driver whose view is blocked cannot see the vehicles around, so you should assume you are invisible and stay out of that vehicle path.
-
33. Why does the manual insist on a firm grip with both hands on opposite sides of the steering wheel?
Show answer
Answer A: A hard bump can pull the wheel out of a loose grip
Hitting a curb or a deep pothole can jerk the wheel violently, and only a firm two-handed grip keeps the vehicle under control when that happens.
-
34. A hard frost has left your vehicle covered in ice. What must be cleared before you drive?
Show answer
Answer D: The windshield, mirrors, lights and reflectors
You must be able to see out and other drivers must be able to see your lights and reflectors, so all of those surfaces have to be cleared.
-
35. Why should water never be used on an electrical fire or a gasoline fire?
Show answer
Answer C: It spreads the fuel and conducts the current
Water carries current back to the person holding the hose and floats burning fuel outward, which is why a B:C rated extinguisher is carried instead.
-
36. Loading heavy freight on top of lighter freight has what effect on the vehicle?
Show answer
Answer B: It raises the center of gravity and makes a rollover more likely
A high center of gravity lets the vehicle tip more easily in curves or during a sudden swerve.
-
37. How is free play in the steering wheel measured during the inspection?
Show answer
Answer B: By turning the wheel until the front wheels just start to move and noting the movement
Play is the movement at the rim that produces no movement at the road wheels, so it is measured by turning until the wheels first respond.
-
38. What does the Virginia CDL restriction coded Q prohibit?
Show answer
Answer D: Transporting children to or from school or licensed child day care activities in a commercial motor vehicle
Virginia's Q restriction bars the holder from operating a commercial motor vehicle to transport children to or from activities sponsored by a school or by a licensed child day care facility.
-
39. Two tires in a dual set have noticeably different diameters. Why is that a problem?
Show answer
Answer C: The larger tire carries more than its share of the load and can be overloaded
The taller tire touches the road first and takes most of the weight, so it runs overloaded and hot while the smaller one does little work.
-
40. What is the correct way to make a normal stop?
Show answer
Answer A: Push the brake pedal down gradually and bring the vehicle to a smooth stop
Steady, progressive pedal pressure keeps the vehicle stable and lets the driver behind you react to a predictable slowdown.
-
41. How does overloading affect the way a vehicle drives?
Show answer
Answer C: It slows the vehicle on upgrades, makes stopping take longer and can overheat the brakes on downgrades
Extra weight demands more from the engine and the brakes, so the vehicle climbs slowly and needs much more distance to stop.
-
42. You are driving past a park where children are playing close to the curb. What is the correct assumption?
Show answer
Answer A: A child may run into the street without looking
Children act on impulse and do not judge traffic well, so a driver has to expect one to enter the road and slow down in advance.
-
43. Who may remove an out-of-service sticker from a commercial vehicle?
Show answer
Answer B: Only an authorized person, and only after the defect that caused it has been repaired
The sticker stays on the vehicle until the repairs are made and an authorized person removes it, so nobody can simply peel it off and drive away.
-
44. A delivery van is stopped in the right lane ahead with its flashers on. What should you expect?
Show answer
Answer C: Someone may step into your lane from in front of it
A stopped delivery vehicle hides the space in front of it, and that is exactly where a person carrying a package is likely to walk out.
-
45. During the walkaround inspection, where does the driver normally start and how does the check proceed?
Show answer
Answer C: At the left front of the vehicle, working around it in a set order that returns to the cab
The walkaround follows the same route every time, starting at the left front and circling the vehicle, so that nothing is skipped when the driver is tired or rushed.
-
46. Which lamp must make the rear registration plate legible after dark?
Show answer
Answer C: A white lamp that lights the plate
A white license plate lamp is required so the plate can be read at night, and a burned out one is a defect like any other lamp.
-
47. Apart from the legal duty, what is the main practical reason for a thorough pre-trip inspection?
Show answer
Answer A: It finds problems that could cause a breakdown or a crash before the vehicle is on the road
A defect found in the yard is an inconvenience, while the same defect found at highway speed can be a crash, so the inspection is where problems are cheapest to fix.
-
48. On a scale, your loaded truck is well under the gross weight limit, but one axle is above the limit for that axle. What does this mean?
Show answer
Answer D: The vehicle is overloaded and the load must be shifted or reduced before you drive on
Each axle and axle group has its own limit and each must be respected; being under the gross limit does not excuse an overloaded axle.
-
49. You are pulling a loaded pneumatic dry bulk trailer and approach an exit ramp posted at 35 mph. What is the safest approach?
Show answer
Answer C: Slow to well below the posted speed before the ramp begins
A dry bulk trailer carries its weight high and the load can move, so the ramp speed posted for a car is far too fast and the slowing must be finished before the curve.
-
50. What should a driver assume about the height posted at a bridge or an overpass?
Show answer
Answer B: That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows
Resurfacing and packed snow raise the road under the structure, so the real clearance can be lower than the posted figure.