Connecticut DMV CDL General Knowledge Practice Test 10

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

Minimum age: 18 years for intrastate driving; 21 years for interstate driving or hazardous materials

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

  1. 1. Why should a long vehicle never swing out to the left before starting a right turn?

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    Answer D: Another driver may read it as a left turn or pass on your right

    Swinging left opens a gap on your right that a car will move into, and it also sends a false message about which way you are going.

  2. 2. What happens to the fine for a moving violation committed in an active Connecticut highway construction zone?

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    Answer D: The court adds a fee equal to the whole original fine

    The Superior Court adds a fee equivalent to one hundred percent of the fine for listed violations committed in a designated work zone.

  3. 3. Around a tractor-trailer, where are the blind areas that other drivers most often sit in unseen?

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    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.

  4. 4. Why is driving much slower than the rest of the traffic dangerous?

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    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.

  5. 5. With the tractor coupled to the trailer, what should you see between the upper and lower fifth wheel plates?

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    Answer A: No space at all between the two plates

    Any daylight between the plates means the trailer is not properly seated on the fifth wheel and the coupling can come apart under load.

  6. 6. During the walkaround you find the reflective conspicuity tape along the trailer caked with road grime. What should you do?

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    Answer B: Clean it, because dirty reflective material cannot make the trailer visible at night

    Reflective sheeting only works if light can reach it and bounce back, so a dirty strip leaves the trailer effectively unmarked to approaching traffic.

  7. 7. 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?

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    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.

  8. 8. 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.

  9. 9. What can repeated violations of the federal phone and texting rules cost a commercial driver?

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    Answer D: Disqualification of the commercial driver license

    Multiple convictions for using a hand-held phone or texting while driving a commercial vehicle lead to disqualification, on top of fines for driver and carrier.

  10. 10. The coolant temperature gauge climbs above its normal range on a long grade. What is the correct response?

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    Answer C: Stop when it is safe to do so and find the cause before going on

    Rising coolant temperature signals a fault such as a lost belt, a leak or a blocked radiator, and continuing can turn a repair into a destroyed engine.

  11. 11. Which lamp must make the rear registration plate legible after dark?

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    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.

  12. 12. How are the extra gears of a multi-speed rear axle or auxiliary transmission usually controlled?

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    Answer D: With a selector knob or switch on the gearshift lever of the main transmission

    A range selector on the shift lever lets the driver choose the extra gear range while shifting the main transmission.

  13. 13. At 55 mph, about how far does a vehicle travel during a typical 3/4 second perception time plus 3/4 second reaction time, before the brakes even begin to work?

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    Answer C: About 120 feet

    Each 3/4 second at 55 mph covers about 60 feet, so perception and reaction together use up roughly 120 feet before braking starts.

  14. 14. You are dropping a loaded trailer in a yard. How far should the landing gear be lowered?

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    Answer A: Until the pads make firm contact and the trailer weight is just off the fifth wheel

    Cranking down until the gear is firmly on the ground and just lifting the load off the fifth wheel makes the trailer stable and lets the tractor pull out cleanly.

  15. 15. 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.

  16. 16. After the first inspection of a trip, how often must cargo securement be checked again?

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    Answer D: Every 3 hours or 150 miles or at each change of duty status, whichever happens first

    The load must be re-checked at whichever of those points arrives first, so a loosening tiedown is found long before it fails.

  17. 17. You must drive well below the speed of surrounding traffic, for example when climbing a steep grade with a heavy load. What should you do?

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    Answer B: Turn on the four-way flashers to warn following traffic, where state law allows it

    Flashers warn faster traffic that a slow-moving vehicle is ahead, which helps prevent rear-end crashes; some states restrict their use while moving, so check the local rule.

  18. 18. Which shock absorber condition is a defect?

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    Answer C: A shock that is leaking, broken or disconnected at either mounting

    A shock that has lost its fluid or its mounting no longer damps the suspension, so the wheel bounces and loses contact with the road.

  19. 19. You normally pull an empty trailer, but today the same tractor is loaded to its legal maximum. What changes about getting under way?

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    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.

  20. 20. 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.

  21. 21. When should a lower gear be selected for a long downgrade?

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    Answer D: Before you start down the hill

    The gear is chosen at the top, while speed is still low, because a heavy vehicle already rolling fast may not go into a lower gear at all.

  22. 22. You are taking a tightly curved highway exit ramp in a long combination. Where should the tractor be placed within the lane?

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    Answer D: Toward the outside of the curve, leaving room for the trailer to track inside

    Because the trailer wheels cut to the inside of the curve, the tractor has to be kept out toward the outer edge so the trailer does not drop a wheel off the inside edge.

  23. 23. When turning left, what should a driver of a long vehicle do before beginning the turn?

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    Answer B: Reach the center of the intersection so the rear wheels clear the corner

    The rear wheels follow a tighter path than the front, so the vehicle must reach the center of the intersection before the turn begins.

  24. 24. Which federal requirement must a first-time Connecticut Class A or Class B applicant satisfy before the skills test?

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    Answer A: Entry Level Driver Training from an approved provider

    Entry Level Driver Training is required for first-time Class A and Class B applicants and for certain endorsements.

  25. 25. How long must the record of a periodic inspection be kept?

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    Answer A: Fourteen months

    The periodic inspection report is retained for fourteen months from the date of the report, which covers the full twelve month cycle plus a margin.

  26. 26. What does Connecticut charge to restore a license or registration after a suspension?

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    Answer C: 175 dollars

    The DMV charges a 175 dollar restoration fee for most suspension types before driving privileges return.

  27. 27. What happens when too much of the load sits over the steering axle?

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    Answer D: The vehicle becomes hard to steer and the axle and its tires can be damaged

    Weight beyond the front axle rating makes the steering heavy and can overload the axle and the tires carrying it.

  28. 28. 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.

  29. 29. You are backing a tractor-trailer in a straight line and the trailer starts to drift to the left. What is the standard correction?

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    Answer D: Turn the top of the steering wheel a little to the left, toward the drift

    Small corrections made in the direction the trailer is drifting bring it back into line; large or opposite movements make the drift worse.

  30. 30. You have chosen 40 miles per hour as your safe speed for a downgrade. How should the brakes be used?

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    Answer A: Brake firmly to about 35, release, and repeat at 40

    Proper technique is firm application to about 5 miles per hour below the safe speed, then full release so the brakes cool before the next application.

  31. 31. What should you check about the air hoses and the electrical cord running to the trailer?

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    Answer D: That they are free of damage, properly connected and not dragging or rubbing

    Lines that chafe on the frame or drag on the road wear through, and a broken line takes away trailer braking or trailer lighting without warning.

  32. 32. The engine has overheated and you need to check the coolant. What is the safe procedure with a pressurized radiator cap?

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    Answer A: Shut the engine off, let the system cool, protect your hands, turn the cap slowly to its first stop so pressure escapes, step back, then remove it

    A hot pressurized system throws steam and boiling coolant out of the opening, so the pressure is released slowly and only after the engine has cooled.

  33. 33. You are inspecting the vehicle alone and need to confirm that the stop lights work. Which method is correct?

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    Answer A: Have a helper press the brake pedal, or apply the brake in a way that keeps it on while you check from outside

    Stop lights are checked from outside the vehicle while the brakes are applied, so a helper or a brake held on is needed.

  34. 34. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?

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    Answer D: Because once your speed is too high you may not get into any gear at all

    If you wait until speed has built up, the lower gear may refuse to engage and you can be left in neutral with no engine braking at all.

  35. 35. 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.

  36. 36. What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?

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    Answer D: 0.04 or higher

    Commercial drivers are held to 0.04, half the limit that applies to a driver of a passenger car in the same state.

  37. 37. Your brakes are starting to fade on a mountain downgrade and a sign shows an escape ramp one mile ahead. What should you do?

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    Answer B: Plan to use the ramp instead of trying to reach the bottom

    Fading brakes on a grade only get worse, and the ramp exists precisely so a driver does not have to gamble on the rest of the descent.

  38. 38. Why does a load of hanging meat in a refrigerated trailer require special care in curves?

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    Answer D: The meat swings and has a high center of gravity, which makes the trailer unstable

    Hanging meat is heavy, sits high and swings, so the trailer can tip in a curve or on a ramp taken at normal speed.

  39. 39. Where should a trailer be dropped, and what else does the driver do before pulling out from under it?

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    Answer C: On solid level ground, with the trailer wheels chocked if it may roll

    A dropped trailer must sit on ground that will carry the landing gear without sinking, and chocks stop it rolling once the tractor and its air supply are gone.

  40. 40. Why should you never back under a trailer whose landing gear is resting on soft or muddy ground?

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    Answer C: The landing gear can sink or collapse and the trailer can drop or tip over

    Soft ground lets the landing gear sink under the load being transferred to it, and a trailer that drops or topples during coupling is extremely dangerous.

  41. 41. What tells you that an air suspension bag has a problem?

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    Answer B: The bag is leaking or damaged, or the vehicle sits unevenly on that side

    An air bag that leaks or is cut lets that corner of the vehicle settle, which throws the load onto the other suspension parts and changes the ride height.

  42. 42. What does Connecticut law say about a hand-held phone in a commercial motor vehicle?

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    Answer C: It may be used only to report an emergency

    The commercial provision bars hand-held phone use and texting outright, leaving only calls about an emergency to the listed services.

  43. 43. Which winter preparation matters most for keeping the road in view?

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    Answer D: Working wipers, washer fluid and a working defroster

    Slush and road spray coat the windshield within minutes in winter, so wipers, washer fluid and the defroster are what keep any view at all.

  44. 44. Dry bulk tanks call for extra caution mainly because of what?

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    Answer C: A high center of gravity combined with a load that can shift

    Dry bulk loads ride high and can move inside the tank, which makes the vehicle easier to tip in a curve.

  45. 45. 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.

  46. 46. 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.

  47. 47. What does the commercial driver manual tell you to do with the parking brake when you leave your vehicle?

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    Answer B: Apply the parking brake every time you leave the vehicle

    The manual is explicit that the parking brake goes on whenever the driver leaves the vehicle, because once nobody is at the controls it is the only thing holding it.

  48. 48. What are you looking for on the brake drums during the walkaround?

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    Answer B: Cracks, dents and any oil or grease that has reached the friction surface

    A cracked or badly scored drum can break apart under braking heat, and oil or grease on the friction surface destroys the braking effort at that wheel.

  49. 49. Federal rules keep recapped and retreaded tires off the front wheels of which vehicle?

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    Answer B: Any bus carrying passengers

    The federal rule names buses: a bus may not run with regrooved, recapped or retreaded tires on its front wheels, because a steer tire failure with passengers aboard takes away steering control.

  50. 50. What does gross vehicle weight mean, as opposed to gross vehicle weight rating?

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    Answer B: The actual weight of the single vehicle plus everything it is carrying

    Gross vehicle weight is what the vehicle actually weighs at that moment; the rating is the maximum the manufacturer allows it to weigh.