Indiana BMV CDL General Knowledge Practice Test 6

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

Minimum age: 18 years; 21 years for interstate commerce and for the school bus endorsement

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

  1. 1. You are pulling away from the curb after a delivery. Why is a mirror check needed first?

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    Answer B: A cyclist or a vehicle may be coming up alongside you

    Traffic and cyclists can arrive alongside a parked vehicle at any moment, so the mirrors must be checked immediately before pulling out.

  2. 2. How do you confirm that the coupling is locked before pulling out of the yard?

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    Answer D: By locking the trailer brakes and pulling gently forward against them

    The tug test loads the coupling in the direction that would pull it apart, so if the jaws are not closed on the kingpin you find out at walking pace.

  3. 3. Does the federal texting ban apply to a company dispatching device mounted in the cab?

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    Answer B: Yes, entering or reading text on it while driving is banned

    The rule is written around the act of reading or entering text on any electronic device, not around who owns the device.

  4. 4. When is tire pressure most accurately compared with the recommended figure?

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    Answer B: When the tires are cold, before the vehicle has been driven

    Recommended pressures are cold pressures, so a reading taken before the tires have heated up is the only one that can be compared directly.

  5. 5. You need fuel and the canopy over the pumps is low. What is the safe way to handle the clearance?

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    Answer B: Stop and check the height at the entrance and at the way out before committing

    Clearance can differ at the entry, under the canopy and at the exit, and a sloping approach changes the effective height, so both ends have to be checked.

  6. 6. 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.

  7. 7. You have countersteered to correct a rear-wheel skid and the vehicle straightens out. What must you be ready for next?

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    Answer D: The vehicle may swing back the other way, so you must steer again to correct it

    A vehicle coming out of a skid tends to overshoot and swing in the opposite direction, and the driver must be ready to countersteer a second time.

  8. 8. You are making a right turn and cannot complete it without swinging into the oncoming lane. An oncoming car is approaching. What should you do?

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    Answer A: Wait and let the oncoming vehicle pass before completing the turn, and do not back up

    The oncoming vehicle has the lane; backing up in traffic is dangerous, so hold your position and finish the turn once the way is clear.

  9. 9. In a vehicle with a manual transmission, when should the clutch be pushed in during a normal stop?

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    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.

  10. 10. 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.

  11. 11. Which combination of warning devices meets the requirement for a stopped commercial vehicle?

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    Answer A: Three reflective triangles, or six fusees, or three liquid burning flares

    A vehicle may carry three bidirectional reflective triangles, six fusees or three liquid burning flares as its warning devices.

  12. 12. A dispatcher tells you to take a trailer you believe is loaded badly enough to be unsafe. What should you do?

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    Answer C: Refuse to move it until the load has been made safe

    The driver may not operate a vehicle whose cargo is not properly distributed and secured, and an instruction from an employer does not change that.

  13. 13. What does the tachometer on the dashboard of a heavy truck show?

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    Answer D: How fast the engine is turning, in revolutions per minute

    The tachometer reads engine speed in rpm, which is what a driver uses to judge shift points in a vehicle with a manual transmission.

  14. 14. You are hauling a sealed trailer and have been told in writing not to open it. How does that affect the en route cargo checks?

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    Answer C: You do not have to inspect the cargo itself, but the vehicle and weight are still yours

    The en route cargo inspection rule does not apply to a driver of a sealed vehicle who has been ordered not to open it, but every other responsibility, including legal weight, remains.

  15. 15. 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.

  16. 16. 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.

  17. 17. 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.

  18. 18. During the vehicle overview, what should the driver look for on the ground under the vehicle?

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    Answer B: Fresh puddles of oil, coolant, grease or fuel

    New stains on the ground are the earliest sign of a leak, so the overview includes a look underneath before anything is opened or started.

  19. 19. What extinguisher rating is required on a vehicle carrying hazardous materials in amounts that need placards?

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    Answer B: 10 B:C or more

    Placarded loads carry a much higher fire risk, so the required extinguisher rating rises to at least 10 B:C.

  20. 20. On a one way street or a divided highway, where are the warning devices placed?

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    Answer B: About 10 feet, 100 feet and 200 feet back toward the approaching traffic

    When traffic can only come from one side, all three devices are spread out behind the vehicle to give approaching drivers a longer warning.

  21. 21. 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.

  22. 22. 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.

  23. 23. A car is following you far too closely. What is the safest response?

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    Answer A: Open up more space ahead so you can slow gradually, avoid sudden changes, and do not speed up

    Extra room in front lets you slow smoothly instead of braking hard, which is exactly what the driver behind cannot cope with.

  24. 24. Why must the steering wheel be moved only a small amount at a time while backing?

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    Answer B: Because a small turn of the wheel produces a large change at the rear of the vehicle

    In reverse, the effect of the steering is greatly magnified at the back of the vehicle, so a small correction is usually all that is needed.

  25. 25. A fire starts in the cargo area of a van trailer. Why should you keep the doors closed until firefighters arrive?

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    Answer D: Opening the doors lets in air that feeds the fire

    A fire in a closed van is starved of oxygen; opening the doors gives it the air it needs to flare up.

  26. 26. 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.

  27. 27. 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.

  28. 28. Experienced commercial drivers scan the road ahead by roughly how much travel time?

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    Answer B: About 12 to 15 seconds

    Looking 12 to 15 seconds ahead gives a heavy vehicle enough room to slow or change lanes smoothly instead of reacting late.

  29. 29. 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.

  30. 30. Apart from the legal duty, what is the main practical reason for a thorough pre-trip inspection?

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    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.

  31. 31. What is generally the safest speed in dense but freely moving highway traffic?

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    Answer D: The speed of the traffic around you, up to the posted limit

    Crashes rise with the difference between your speed and the traffic around you, so moving with the flow within the legal limit is safest.

  32. 32. What is the main purpose of a retarder fitted to a heavy vehicle?

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    Answer B: To help slow the vehicle and reduce the need to use the service brakes

    Exhaust, engine, hydraulic and electric retarders all slow the vehicle so the brakes stay cool and wear less, especially on grades.

  33. 33. 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.

  34. 34. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?

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    Answer B: Driving too fast for the conditions

    A front-wheel skid usually comes from too much speed for the traction available; the only cure is to let the vehicle slow down and stop turning or braking so hard.

  35. 35. 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.

  36. 36. When should the horn of a commercial vehicle be used?

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    Answer C: Only when it is needed to avoid a crash

    An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.

  37. 37. Besides the hours when the law requires them, when should headlights be switched on?

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    Answer A: Any time visibility is poor, such as in rain, fog or at dusk

    Headlights are used to be seen as much as to see, so they belong on whenever light or weather makes the vehicle harder to spot.

  38. 38. You press on a drive belt and it deflects far more than the others. What does that suggest?

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    Answer C: The belt is too loose and the part it drives may not work properly

    A belt with excessive play slips on its pulleys, so the accessory it drives turns too slowly or not at all under load.

  39. 39. 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.

  40. 40. 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.

  41. 41. While double clutching, what goes wrong if you take too long between the two clutch movements?

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    Answer A: Engine speed falls too far and the gear becomes hard or impossible to engage

    Double clutching only works while engine speed and road speed still match; a slow shift lets rpm drop away and the gear will not go in.

  42. 42. A tire has a cut deep enough to expose the body ply or the belt material. What does that mean?

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    Answer D: The vehicle must not be driven on that tire

    Once the structural plies are exposed the casing has lost its strength, and federal rules treat that tire as unfit for the road.

  43. 43. How much sleep does a typical adult driver need each day to stay properly alert?

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    Answer D: Seven to eight hours

    Most adults need seven to eight hours of sleep in every 24 hours, and a driver who regularly gets less builds up a debt that shows up behind the wheel.

  44. 44. At the end of the day you find no defects on a property carrying vehicle. What does the federal rule require?

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    Answer B: No written report is required, although the carrier may still ask for one

    For property carrying vehicles the report is required only when a defect or deficiency is found or reported, although a carrier may impose a stricter policy.

  45. 45. 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.

  46. 46. 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.

  47. 47. How should the headlamps be checked during the pre-trip inspection?

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    Answer A: By switching on both low beam and high beam and confirming each one works outside

    Both beams are separate circuits, so each is switched on in turn and confirmed from outside the vehicle where the lamps can actually be seen.

  48. 48. What does the gross vehicle weight rating of a vehicle describe?

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    Answer A: The maximum loaded weight of that single vehicle, as specified by the manufacturer

    The rating is the manufacturer figure for the loaded weight of one vehicle, so it is a limit fixed in advance rather than a measurement of the load on board today.

  49. 49. You are given a ratchet strap with a deep cut along one edge. What should you do?

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    Answer C: Do not use it; a damaged tiedown cannot be relied on to hold its rated load

    Cuts, burns, knots and broken stitching weaken a strap far below its marked working load limit, so it must be taken out of service.

  50. 50. You are about to slow down sharply on a highway to make a turn into a narrow driveway. How can you warn the drivers behind you?

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    Answer C: Tap the brake pedal a few times so the brake lights flash before you slow down

    A few light taps flash the brake lights and give following drivers an early warning that you are about to slow or stop.