New Jersey MVC CDL General Knowledge Practice Test 3

Test 3 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 New Jersey test.

A highway along the shore with a boardwalk, a typical landscape of New Jersey

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

  1. 1. What is wrong with resting your foot on the clutch pedal between shifts?

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    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.

  2. 2. Cargo falls from your trailer and causes a crash behind you. Who is likely to answer for it?

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    Answer C: The driver and the carrier, since securing the load on the road is their duty

    Whoever loaded the vehicle, the driver and the carrier are responsible for the load being secure while it is on the road.

  3. 3. What must be checked about the cargo doors and any tarpaulin before a trip?

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    Answer B: That the doors are closed and latched and that any tarp is tied down securely

    An unlatched door or a loose tarp can swing open or tear free at speed, spilling cargo or blocking the view of the traffic behind you.

  4. 4. An automatic transmission is left in its normal drive position as the vehicle rolls down a long grade. What does it tend to do?

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    Answer A: Shift up as road speed rises, so engine braking falls away

    An automatic left in drive keeps upshifting as speed builds, which is the opposite of what you want on a grade; that is why the driver must select a low range.

  5. 5. After coupling, where should the fifth wheel release handle be?

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    Answer A: In the locked position with the safety latch in place

    The handle must be pushed in and latched, because a handle left out means the jaws can open and release the trailer while you are driving.

  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. 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.

  8. 8. What is the minimum tread depth required in every major groove of a steering axle tire?

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    Answer D: 4/32 inch

    Federal rules set a higher tread minimum for front steering tires than for other positions because a steering tire failure is far harder to control.

  9. 9. An empty van trailer cleared a low overpass on the way in, but on the way back it is loaded. Which statement is true?

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    Answer C: An empty van rides higher than a loaded one, so it needs more clearance than when loaded

    Springs compress under load, so an empty trailer is taller; the unloaded trip is the one that can catch a low overhead.

  10. 10. 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.

  11. 11. Your windshield washer reservoir is empty and rain and road spray are expected. What should you do?

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    Answer D: Fill it before the trip, because you need the washers to keep the windshield clear

    Wipers alone smear the film of oil and grit thrown up by traffic, so the washers are part of keeping a usable view of the road.

  12. 12. The shipper hands you the placards for a load that needs them. Who puts them on the vehicle?

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    Answer C: The driver, who must also make sure they are the correct ones and are readable

    The shipper supplies the placards, but it is the driver who must place them on the vehicle and confirm that they match the load and can be read.

  13. 13. What is the correct way to test the parking brake before a trip?

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    Answer C: With the parking brake set, put the vehicle in a low gear and gently try to move forward

    A parking brake that holds against a gentle pull in low gear is working; if the vehicle moves, the brake needs adjustment or repair.

  14. 14. What is the correct way to make a right turn in a long vehicle?

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    Answer D: Keep the rear of the vehicle close to the curb and swing wide only as you complete the turn

    Swinging left before a right turn invites another driver to move into the gap on your right, so any extra width is taken as the turn is finished.

  15. 15. When must a driver first inspect the cargo and its securement devices?

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    Answer C: Before starting the trip, as part of the pre-trip inspection

    Cargo is part of the pre-trip inspection; the later checks within 50 miles and every three hours or 150 miles come on top of that first inspection.

  16. 16. Which set of emergency equipment must be carried on a commercial motor vehicle?

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    Answer D: A fire extinguisher, spare electrical fuses unless the vehicle has circuit breakers, and warning devices

    The required kit is a properly charged and rated fire extinguisher, spare fuses when the vehicle uses them, and warning devices for a stopped vehicle.

  17. 17. What blood alcohol concentration is unlawful for someone operating a commercial motor vehicle in New Jersey?

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    Answer C: 0.04 percent or higher

    New Jersey sets the commercial vehicle threshold at 0.04 percent, half the limit that applies to ordinary drivers.

  18. 18. What is the driver looking for when the exhaust system is inspected?

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    Answer B: Loose, broken or missing pipes, brackets or clamps, and signs that exhaust is leaking

    A loose or leaking exhaust system can send carbon monoxide into the cab and can put hot gas against parts that will burn.

  19. 19. When traction is poor, such as on packed snow, how should you speed up?

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    Answer C: Very gradually, so the drive wheels do not spin

    Gentle throttle keeps the drive wheels from breaking traction, because spinning wheels give up both grip and directional control.

  20. 20. Which of these is NOT on the federal list of parts and accessories the driver must be satisfied are in good working order before driving?

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    Answer D: The seat cushion upholstery

    The federal pre-trip rule names brakes, steering, lights and reflectors, tires, horn, wipers, mirrors, coupling devices, wheels and rims, and emergency equipment; seat upholstery is not on that list.

  21. 21. Why must a bent, cracked or badly seated lock ring be reported?

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    Answer D: It can come off under pressure and let the tire and rim separate violently

    The lock ring holds the assembly together against the full pressure of the tire, so a damaged ring can release with enough force to kill.

  22. 22. You need to check your route on a navigation device. What is the correct approach?

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    Answer D: Set it before the trip or after you have parked

    Route programming is planning work, and it belongs to the time before the wheels turn or after the vehicle is safely parked off the roadway.

  23. 23. On a wet road, a commercial driver should reduce speed by roughly how much?

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    Answer C: By about one third

    Cutting speed by roughly a third, for example from 55 to about 35 mph, restores a margin for the traction lost on a wet surface.

  24. 24. Your right wheels drop off the pavement onto a soft shoulder. What is the correct recovery?

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    Answer A: Stay on the shoulder, ease off the accelerator, brake gently only once speed is down to about 20 mph, then steer back sharply and countersteer at once

    Bringing speed down on the shoulder first avoids a violent sideways jolt, and countersteering the instant the tires are back on the pavement keeps the vehicle out of the next lane.

  25. 25. Which exhaust system condition must be reported as a defect?

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    Answer B: A section repaired by wrapping tape or patching material around the pipe

    Exhaust parts may not be patched with wrap or tape, because the repair does not contain the gas or the heat and it fails quickly in service.

  26. 26. How should speed and gears be handled when approaching a curve?

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    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.

  27. 27. An article of cargo has been blocked so that it cannot move forward. How many tiedowns does the federal rule call for?

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    Answer A: One tiedown for every 10 feet of article length, or any part of that

    Blocking against forward movement lowers the requirement to one tiedown per 10 feet of length or fraction of 10 feet.

  28. 28. Which other endorsement must a New Jersey driver hold along with the school bus, or S, endorsement?

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    Answer A: The passenger, or P, endorsement

    New Jersey requires both the S and the P endorsements before a driver may operate a school bus.

  29. 29. Most rollovers of loaded trucks on exit and entrance ramps happen for which reason?

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    Answer B: The ramp was taken faster than the load could tolerate

    A posted ramp speed is set for cars, and a loaded trailer with a high center of gravity can roll at a speed a car would take easily.

  30. 30. The brake pedal goes to the floor in a vehicle with hydraulic brakes. What can you do to build some braking pressure?

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    Answer B: Pump the brake pedal rapidly, which may bring back enough pressure to slow the vehicle

    Pumping can restore some hydraulic pressure; along with downshifting and the parking brake it is one of the ways to stop when the pedal fails.

  31. 31. Regular mirror checks during a long trip can reveal which developing problem?

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    Answer D: Smoke coming from a tire or from a wheel

    Overheating tires, wheel bearings and brakes usually show as smoke long before anything appears on the dash, and mirrors are where a driver sees it.

  32. 32. You are hauling an open box of loose gravel. What does that load require?

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    Answer A: A cover, so that material cannot blow off or spill onto the road

    Loose material that can be blown or spilled has to be covered so it does not come out of the body and strike traffic behind.

  33. 33. Apart from the risk of stalling, why is rolling backwards when starting on an upgrade so serious in a heavy vehicle?

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    Answer D: You can strike the vehicle behind you, which is often much closer than you think

    You cannot see how close the vehicle behind has stopped, and even a short roll back is enough to hit it.

  34. 34. What information does an inspection decal on a commercial vehicle carry?

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    Answer B: The date of the inspection, where the inspection report is kept, and information identifying the vehicle

    The decal shows when the inspection was done, the name and address of the entity that holds the inspection report, and which vehicle it belongs to, so an officer can confirm the inspection at a glance.

  35. 35. How is a shipping container normally secured when it is carried on a special container chassis?

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    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.

  36. 36. What are you checking when you look at the batteries during the engine compartment inspection?

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    Answer D: That they are securely mounted, the connections are tight and free of corrosion, and the caps are in place

    Loose or corroded batteries can fail or short out, so the mount, cables, terminals and vent caps are all part of the check.

  37. 37. How soon must warning devices be placed after a commercial vehicle stops on the traveled part or the shoulder of a highway?

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    Answer D: As soon as possible and in any case within 10 minutes

    The hazard warning flashers go on immediately and the warning devices must be in place as soon as possible, never later than 10 minutes after stopping.

  38. 38. If an intersection has two lanes marked for left turns, which one should a large vehicle use?

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    Answer D: The right hand of the two turning lanes

    The outside turning lane leaves room for the rear of the vehicle to swing without striking a vehicle in the adjacent lane.

  39. 39. Why does a load need to be balanced from side to side?

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    Answer B: Because a heavy side raises the rollover risk and can overload the tires and springs on that side

    An uneven load tips the balance of the vehicle in curves and pushes the tires and suspension on the loaded side past their rating.

  40. 40. Where on a tire is tread depth measured?

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    Answer C: In a major tread groove, away from any tie bar or wear indicator

    Depth is taken in a major groove and away from the raised tie bars and wear indicators, which would give a shallower and misleading reading.

  41. 41. 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.

  42. 42. Why should water never be used on an electrical fire or a gasoline fire?

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    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.

  43. 43. How does overloading affect the way a vehicle drives?

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    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.

  44. 44. You are pulling away from a curb in a 65 foot combination. Besides traffic, what must you watch?

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    Answer B: The trailer wheels, which stay close to the curb and can strike it or an object on it

    Because of off-tracking, the rear wheels follow a tighter path than the front, so they stay near the curb while the cab is already out in the lane.

  45. 45. Which set of maneuvers makes up the basic control skills part of the commercial driving test?

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    Answer D: Straight line backing, offset backing, parallel parking and alley docking

    The basic control skills test is carried out off the road and consists of low speed exercises such as straight line backing, offset backing, parallel parking and the alley dock.

  46. 46. What are you looking for when you check the hubs and wheel seals during the walkaround?

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    Answer B: Leaking oil or grease, which can also contaminate the brake linings

    A leaking hub seal starves the bearing of lubricant and the escaping oil or grease can soak the brake linings and cut braking power.

  47. 47. The car in the next lane still has snow covering most of its windows. What should you assume?

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    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.

  48. 48. At 55 mph on dry pavement with good brakes, total stopping distance for a loaded heavy vehicle is roughly what?

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    Answer B: About 400 feet or more

    Perception, reaction, and braking together add up to roughly 400 feet or more, farther than the length of a football field.

  49. 49. Your vehicle stalls on a railroad crossing and a train is coming. What should you do?

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    Answer C: Get out at once and move toward the train, well off to one side

    Leave the vehicle immediately and move at an angle toward the oncoming train, so that wreckage thrown forward by the impact travels away from you.

  50. 50. 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.