Oklahoma SOK CDL General Knowledge Practice Test 9

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

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

  1. 1. A 60 foot combination traveling above 40 mph should hold how many seconds of following distance?

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    Answer D: Seven seconds

    Six seconds cover the 60 feet of vehicle length, and one extra second is added because the speed is above 40 mph.

  2. 2. What is the payload of a truck?

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    Answer C: The weight of the cargo the vehicle is carrying, that is the loaded weight less the empty weight

    Payload is what is left of the legal or rated weight once the weight of the empty vehicle is taken off, and it is the weight of cargo that can be carried.

  3. 3. 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.

  4. 4. What training does Oklahoma require of an entry level commercial driver applicant?

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    Answer D: Training from a provider listed on the FMCSA Training Provider Registry

    Oklahoma applies the federal entry level driver training rule, so a first time commercial driver must complete training with a provider listed on the FMCSA Training Provider Registry.

  5. 5. A driver hauling a sealed trailer that cannot be opened is still responsible for what?

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    Answer D: Making sure the rig is not over the gross or axle weight limits

    A seal prevents inspecting the contents, but the driver must still confirm the vehicle is not overloaded.

  6. 6. 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.

  7. 7. 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.

  8. 8. Your speedometer stops working during the pre-trip check. How should it be treated?

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    Answer D: As a defect, because the driver cannot judge and control speed without it

    A working speedometer is required equipment, because judging speed by feel in a heavy vehicle is unreliable and speed governs stopping distance.

  9. 9. 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.

  10. 10. 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.

  11. 11. 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.

  12. 12. Which vehicles are most likely to get hung up on a raised railroad crossing?

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    Answer A: Low-slung units such as car carriers and lowboys

    Vehicles with low ground clearance or a long wheelbase can bottom out on a humped crossing and become stuck on the tracks.

  13. 13. 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.

  14. 14. An enforcement officer inspects your vehicle at the roadside and attaches an out-of-service sticker. What may you do?

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    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.

  15. 15. 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.

  16. 16. 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.

  17. 17. What is the fine for a commercial or public transit driver convicted of using a hand-held cellular telephone while operating a vehicle in Oklahoma?

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    Answer A: $500

    Oklahoma's statute on unlawful use of a cellular telephone by commercial and public transit drivers sets a $500 misdemeanor fine, five times the fine for the general texting ban.

  18. 18. When should a driver select the gear for a long, steep downgrade?

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    Answer B: Before starting down the grade

    The low gear has to be chosen before the descent, because a heavy vehicle gaining speed may refuse to shift down at all.

  19. 19. You are backing into a yard where electrical wires cross overhead. What is the main concern?

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    Answer C: The wires may hang lower than the top of your vehicle

    Overhead space has to be checked like any other space around the vehicle, because wires and cables are often lower than they look from the cab.

  20. 20. Compared with a fully loaded one, an empty truck under hard braking will often do what?

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    Answer A: Need a longer distance to stop because traction is poor

    Stiff suspension and little weight over the tires reduce grip, so the wheels lock early and the vehicle can take longer to stop.

  21. 21. You are pulling a loaded pneumatic dry bulk trailer and approach an exit ramp posted at 35 mph. What is the safest approach?

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    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.

  22. 22. A delivery van is stopped in the right lane ahead with its flashers on. What should you expect?

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    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.

  23. 23. A commercial vehicle stops on the shoulder of a one-way or divided highway. Where do the three warning devices go?

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    Answer A: At 10 feet, 100 feet, and 200 feet back toward approaching traffic

    Traffic arrives from one direction only, so all three devices are set back toward it at 10, 100, and 200 feet, and they must be out within ten minutes.

  24. 24. You are loading lengths of large diameter pipe on a flatbed. What is needed besides the tiedowns?

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    Answer D: Chocks, wedges or cradles that keep the pipe from rolling

    Anything that can roll must be prevented from rolling by chocks, wedges, cradles or a similar device that is itself secured so it cannot come out.

  25. 25. 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.

  26. 26. 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.

  27. 27. An overpass you have driven under before now has a fresh layer of pavement on the road below it. Why does that matter?

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    Answer B: The new layer raises the road and reduces the clearance

    Repaving lifts the road surface, so the real clearance under a structure can be less than the height posted on it.

  28. 28. What does the gross combination weight rating cover?

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    Answer B: The maximum loaded weight of the power unit together with the trailer or trailers it tows

    The combination rating takes in the power unit and everything behind it, loaded, as specified by the manufacturer.

  29. 29. 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.

  30. 30. What does a K restriction mean on an Oklahoma commercial driver license?

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    Answer D: The driver cannot leave the state of Oklahoma with CDL vehicles

    Oklahoma applies the K restriction to intrastate only drivers, meaning the holder cannot take a commercial vehicle out of Oklahoma.

  31. 31. On a multilane highway, which lane should a heavy vehicle normally use?

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    Answer A: The right lane, except to pass or where signs direct otherwise

    Keeping right leaves the faster lanes free and reduces the number of vehicles that have to move around a slower, heavier vehicle.

  32. 32. 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.

  33. 33. While checking the in-cab gauges after start-up, what should the coolant temperature gauge do?

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    Answer C: Rise gradually to the normal operating range

    A healthy cooling system warms the engine slowly; a gauge that shoots up or stays cold points to a problem with the thermostat, coolant or sensor.

  34. 34. During the walkaround you notice a bulge in the sidewall of a trailer tire. What does it indicate?

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    Answer B: Damage inside the tire, which can lead to a sudden failure

    A bulge means the internal structure has broken and only the rubber is holding the air, so the tire can burst without warning.

  35. 35. Why should a driver avoid shifting gears in the middle of a turn at an intersection?

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    Answer D: Shifting during the turn takes a hand off the wheel and can cost you control

    Pick the gear before you begin turning; shifting in the turn removes a hand from the wheel and can interrupt power just when you need steady control.

  36. 36. Oklahoma's ban on hand-held phone calls for public transit drivers reaches which additional operator, beyond bus and transit vehicle drivers?

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    Answer C: Operators, conductors or drivers of a locomotive engine, railway car or train

    Oklahoma's statutory definition of public transit driver, for purposes of the hand-held phone ban, extends to any operator, conductor or driver of a locomotive engine, railway car or train of cars.

  37. 37. Your load projects more than 4 feet beyond the rear of the vehicle. How must the projecting end be marked?

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    Answer A: With a red or orange flag by day and a red lamp after dark

    Federal rules require a warning flag on a rear projecting load in daylight and a red lamp on the end of it when lights are required.

  38. 38. 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.

  39. 39. What must the driver confirm about the required emergency equipment before a trip?

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    Answer A: That it is in place, in working order and ready to be used

    Federal rules require the driver to be satisfied that the emergency equipment is present and ready, because it is needed at the worst possible moment.

  40. 40. Which Oklahoma CDL endorsement is required to drive a vehicle designed to carry 16 or more people including the driver?

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    Answer B: P endorsement

    Oklahoma requires the P passenger endorsement, obtained through written and skills testing, for vehicles with a design capacity of 16 or more people including the driver.

  41. 41. How can a driver restart the 60 or 70 hour on-duty limit?

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    Answer B: Take 34 or more consecutive hours off duty

    A period of 34 or more consecutive hours off duty resets the 60 or 70 hour calculation so the driver can begin a new period.

  42. 42. What should you do before backing into a space you have not used before?

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    Answer A: Get out and walk around to check the path, the clearance and any obstacles

    Walking the area first reveals low obstructions, soft ground and objects that never appear in the mirrors.

  43. 43. 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.

  44. 44. 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.

  45. 45. 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.

  46. 46. 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.

  47. 47. What should be done before a night trip to get the most from your headlights?

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    Answer C: Clean the windshield, the mirrors and the lights

    Dirt on glass and lenses cuts both the light you throw down the road and the light that reaches your eyes, so cleaning is the cheapest night safety measure there is.

  48. 48. 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.

  49. 49. 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.

  50. 50. What tells a driver when to shift up in a vehicle with a manual transmission?

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    Answer C: Engine speed in rpm together with road speed

    Shift points are judged from engine rpm and road speed, using the operating range the manufacturer specifies for that engine.