New Jersey MVC CDL General Knowledge Practice Test 9

  • Questions50
  • Correct to pass40
  • Passing score80%
  • Minimum age18 years

Minimum age: 18 years, interstate driving and hazardous materials or passenger endorsements require 21

50 questions. Pick an answer to see if it is right and why; you need 40 correct answers to pass.

  1. 1. Within what distance should high beams be lowered at night?

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    Answer D: Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following

    High beams blind other drivers at close range, so they are lowered at roughly the same distance whether the other vehicle is coming toward you or is ahead of you.

  2. 2. You hear air escaping from a trailer tire during the pre-trip. What should you do?

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    Answer C: Have it repaired or replaced before the vehicle is driven

    An audible leak means the tire is failing now, and federal rules do not allow a vehicle to be operated on a flat or leaking tire.

  3. 3. What should you do with the previous driver vehicle inspection report before starting your trip?

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    Answer B: Review it and confirm that listed defects were certified as repaired or as not needing repair

    Reviewing the last report and the carrier certification tells you whether reported defects have been corrected before you take the vehicle out.

  4. 4. The rear wheels of your vehicle lock during braking and the rear starts to slide sideways. What should you do first?

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    Answer A: Stop braking so the rear wheels can roll again, then steer quickly in the direction you want to go

    Locked wheels have no side grip; releasing the brakes restores traction and then countersteering brings the vehicle back into line.

  5. 5. A chain rated at 6,600 pounds is fitted with a hook rated at 4,700 pounds. What is the working load limit of that assembly?

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    Answer A: 4,700 pounds, the rating of the weakest part

    An assembly is only as strong as its weakest component, so hooks, binders and links all count and the lowest rating governs.

  6. 6. Besides staying secure, cargo carried inside a vehicle must not do what?

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    Answer C: Block the driver view or access to emergency equipment and exits

    Cargo may not obstruct the view to the front or sides or prevent the driver from reaching emergency equipment and exits.

  7. 7. You are hauling a load of steel plate that is well within every weight limit but is stacked five feet high on a flatbed. What is the main concern?

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    Answer A: The center of gravity is high, so the rig will roll more easily in a curve

    Legal weight does not make a load safe; height raises the center of gravity and it is height, not weight alone, that decides how readily the vehicle rolls over.

  8. 8. A driver is tailgating you, honking and making gestures. What is the best response?

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    Answer A: Do not make eye contact, ignore the gestures and give the driver room to get past

    Engaging an aggressive driver only escalates the situation; the safest move is to stay calm, avoid eye contact and let the driver get by.

  9. 9. What should a driver assume about the height posted at a bridge or an overpass?

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    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.

  10. 10. During the engine compartment check, which leaks are you looking for?

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    Answer D: Fuel, coolant, engine oil, power steering fluid and battery fluid

    Every fluid in the compartment matters, because a fuel leak is a fire risk and a loss of coolant, oil, steering fluid or electrolyte can disable the vehicle.

  11. 11. A tire may be regrooved only when what is true?

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    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.

  12. 12. A vehicle carries placards on its front, rear and both sides. What is the main purpose of those placards?

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    Answer C: To tell emergency responders and other people what hazard the cargo presents

    Placards warn everyone around the vehicle, especially emergency responders, about the kind of hazard the cargo presents.

  13. 13. What is checked in step six of the seven-step method?

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    Answer D: The turn signals and the stop lights, checked from outside the vehicle

    Step six returns to the cab to switch on the signal and stop lamps, then checks each one from outside, because those lamps are not lit during the earlier light check.

  14. 14. Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?

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    Answer B: Gravity adds to the momentum and the brakes heat up faster

    The heavier the vehicle, the more energy the brakes must turn into heat, and heat is exactly what makes brakes fade on a long descent.

  15. 15. On packed snow, how much should a commercial driver reduce speed?

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    Answer D: By about one half or more

    Packed snow costs far more traction than rain, so speed should be cut by half or more.

  16. 16. As a long vehicle goes around a corner, how do the rear wheels travel compared with the front wheels?

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    Answer A: They follow a tighter path, closer to the inside of the turn

    The rear wheels off-track toward the inside of the turn, and the longer the vehicle the bigger the difference, which is why the front must swing wide enough to keep the rear off the curb.

  17. 17. How much free play in the steering wheel is enough to make a vehicle hard to steer and should be reported?

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    Answer B: More than 10 degrees, roughly 2 inches of movement at the rim of a 20 inch wheel

    Excess play means steering input is lost before the wheels respond, and more than about 10 degrees is treated as a defect.

  18. 18. What is the purpose of an escape ramp on a mountain grade?

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    Answer C: To stop a runaway vehicle without injuring the driver

    Escape ramps use soft material or a steep upgrade to bring a vehicle with failed brakes to a controlled stop.

  19. 19. How do you test for leaks in a hydraulic brake system during the pre-trip inspection?

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    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.

  20. 20. A commercial driver is convicted of two serious traffic violations within three years. What is the result?

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    Answer D: Disqualification for 60 days

    Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.

  21. 21. At a stop on a hot day you find a tire that is too hot to touch. What should you do?

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    Answer C: Wait until the tire cools before driving on, and do not let air out of it

    A tire that is too hot to touch may be about to fail or catch fire; releasing air only leaves it underinflated once it cools, which makes things worse.

  22. 22. You stop to check the load. Which set of things are you looking at?

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    Answer C: Tight tiedowns, cargo that has not moved, secure doors and tarps still fastened

    A cargo check covers the load and everything holding it: whether it has shifted, whether the devices are still tight, and whether doors and covers are still closed and fastened.

  23. 23. A tire blows out at highway speed. What should the driver do first?

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    Answer C: Hold the steering wheel firmly, stay off the brake and let the vehicle slow down

    Braking while a tire is gone can pull the vehicle out of line, so the driver keeps it straight and lets speed fall before easing off the road.

  24. 24. The combined working load limit of the tiedowns on a load must equal at least what share of the cargo weight?

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    Answer C: One half of the cargo weight

    Federal securement rules set the aggregate working load limit at no less than half the weight of the article or group of articles being held.

  25. 25. What should you look for on the electrical wiring in the engine compartment?

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    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.

  26. 26. What is normally required in order to move an over-width or over-length load?

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    Answer B: A special permit along with warning devices such as flags and signs

    Oversize movements need a permit plus marking devices, and travel is often limited to certain hours or routes.

  27. 27. Under federal safety rules, what must the driver of a commercial vehicle do before starting a trip?

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    Answer A: Be satisfied that the vehicle is in safe operating condition

    The driver is responsible for inspecting the vehicle and must be satisfied it is in safe operating condition before the trip begins.

  28. 28. You have a part load that fills only a third of a long trailer. How should it be placed?

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    Answer C: Spread out and centerd side to side, so the weight sits over the axles

    A part load is spread over as much of the floor as possible and kept centerd, so no axle is overloaded and the vehicle stays balanced from side to side.

  29. 29. What does it mean to overdrive your headlights at night?

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    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.

  30. 30. Why must tiedowns be rechecked during a trip even when they were tight at the start?

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    Answer C: Road vibration and cargo movement can loosen them as the miles go by

    Straps and chains settle and loosen as the vehicle bounces and the cargo shifts slightly, so the load must be rechecked at the required intervals.

  31. 31. A car that passed you on the right slows and stays alongside your trailer. What is the best response?

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    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.

  32. 32. You are loading a flatbed that has no sides or bulkheads. How must the cargo be held?

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    Answer D: By tiedowns, blocking or bracing, since there are no walls to keep it from shifting or falling off

    Open decks depend entirely on securement devices; every article must be tied down or otherwise immobilized so it cannot move, spill or fall.

  33. 33. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?

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    Answer A: Steer into an open field or onto a side road that flattens out or climbs uphill

    A flat or uphill escape route uses gravity and rolling resistance to stop the vehicle; take it as soon as you see it, because the longer you wait the faster you go.

  34. 34. After starting the engine, how quickly should the oil pressure gauge come up to its normal range?

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    Answer B: Within a few seconds

    Oil pressure should build within seconds of starting; if it stays low, the engine is not being lubricated and should be shut down.

  35. 35. Besides slowing down, which technique most reduces the risk of a skid on a snow covered road?

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    Answer B: Make every steering, braking and speed change gradual

    Traction is limited on snow, and sudden inputs demand more grip than the surface can supply, so smoothness is what keeps the tires attached to the road.

  36. 36. Two vehicles of exactly the same length make a right turn, one gently and one very tightly. What is the effect on off-tracking?

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    Answer A: Turning more sharply increases off-tracking, so the tight turn needs more room

    Off-tracking depends on both the length of the vehicle and the sharpness of the turn; a tighter corner brings the rear wheels further inside the path of the front wheels.

  37. 37. You pick up a sealed trailer at a shipper. What should you check before leaving the dock?

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    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.

  38. 38. How does a driver keep a vehicle with a manual transmission from rolling back when starting on an upgrade?

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    Answer D: Partly engage the clutch before the right foot leaves the brake, or hold the vehicle with the parking brake until the engine pulls

    Something has to hold the vehicle during the instant the foot moves from the brake to the accelerator, and that is either the clutch at its engagement point or the parking brake.

  39. 39. What is the driver responsible for when a load is covered with a tarp?

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    Answer C: Fastening it so it cannot flap free, block a mirror, or come off in the wind

    A tarp that works loose can tear away, block the driver view or the view of others, and become a hazard for the traffic behind.

  40. 40. Why does a cracked frame rail or cross member make a vehicle unsafe?

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    Answer B: The frame carries the whole load, and a crack can spread until the structure fails

    The frame is the backbone that supports the body, the load and the running gear, so a crack in it is a structural failure that grows with every mile.

  41. 41. For an unblocked article longer than 10 feet, the minimum is two tiedowns plus how many more?

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    Answer B: One more for every additional 10 feet of length or any part of 10 feet

    Past the first 10 feet, one more tiedown is added for each additional 10 feet of length or any fraction of that distance.

  42. 42. Which clues warn you that a parked car may pull out or open a door?

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    Answer A: Exhaust smoke, turned front wheels, a person in the seat

    Signs of life in a parked vehicle, such as a running engine, turned wheels or an occupant, mean it may move or open a door into your path.

  43. 43. On a tractor with a sliding fifth wheel, what does moving the fifth wheel forward do?

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    Answer A: Puts more of the trailer weight onto the steering axle

    Moving the coupling point forward transfers weight from the drive axles to the steering axle, which is how a driver corrects a drive axle that is over the limit.

  44. 44. When a helper guides you while backing, what should be agreed on before you start?

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    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.

  45. 45. What vision standard must a New Jersey commercial driver license applicant meet?

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    Answer D: 20/40 in both eyes, with or without lenses, plus the ability to distinguish red, green and amber lights

    Commercial applicants must reach 20/40 in both eyes and must be able to tell red, green and amber signals apart.

  46. 46. What is the first step of the standard seven-step vehicle inspection?

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    Answer C: A general overview of the vehicle, including the last inspection report

    The routine opens with a walk-up overview of the vehicle and a review of the previous inspection report so known defects are addressed first.

  47. 47. Under federal rules, what is required of a commercial driver who wants to use a mobile phone while driving?

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    Answer B: The phone must be hands-free and started with no more than a single button press, and it must not be held

    Federal rules ban texting and hand-held phone use while driving a commercial vehicle; reaching for, holding or dialing a phone is a violation.

  48. 48. What do you check about the fire extinguisher during the pre-trip?

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    Answer C: That it is securely mounted, charged and that you know how to operate it

    An extinguisher must be held in its bracket, show a charged gauge and be understood by the driver, because a fire leaves no time to learn.

  49. 49. What is the coupling device weight rating on a vehicle?

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    Answer A: The most weight that the coupling on the vehicle is rated to pull

    The coupling device rating is a limit on how much weight the coupling may tow, and it is one of the ratings that has to be respected when a combination is loaded.

  50. 50. What is the correct order for a basic double clutch upshift?

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    Answer B: Release the accelerator and push the clutch, shift to neutral, release the clutch, let engine speed drop, push the clutch again and shift to the higher gear

    Double clutching passes through neutral with the clutch released so engine speed can drop to match the next gear before it is engaged.