Nebraska DMV CDL General Knowledge Practice Test 7
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. How are the headlights, marker lights and turn signals checked during the seven-step inspection?
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Answer A: The engine is shut off, the parking brake is set, the lights are switched on and then checked from outside the vehicle
The lights are switched on with the vehicle secured, then the driver walks around and confirms each lamp actually works and is clean.
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2. 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.
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3. How do you get more engine braking from an automatic transmission on a downgrade?
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Answer B: Select a lower range before starting down
Locking the transmission into a lower range keeps engine speed high enough to hold the vehicle back and spares the service brakes.
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4. 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.
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5. You must leave the vehicle parked on a slight grade. What adds security beyond setting the parking brake?
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Answer D: Chocking the wheels so the vehicle cannot roll if the brake bleeds off
Chocks hold the vehicle mechanically and are the standard backup whenever a parked vehicle could roll.
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6. 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.
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7. 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.
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8. 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.
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9. The paperwork shows a weight, but the load looks heavier than you expected. What should you do?
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Answer C: Weigh the vehicle, since you are the one answerable for driving it overweight
The driver is the one who can be cited for an overweight vehicle, so a doubtful weight is settled on a scale before the trip continues.
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10. You are strapping down a load with sharp metal edges on a flatbed. What should you use?
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Answer D: Edge protection between the strap and the sharp edges so the tiedown is not cut
Sharp edges cut or wear through a strap under tension, so edge protectors are required wherever a tiedown could be damaged.
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11. A hazard suddenly appears ahead and you must act. Which is usually the faster way to avoid it in a heavy vehicle?
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Answer B: Steering around it, because you can usually turn faster than you can stop
Stopping distance at speed is very long, so a quick turn out of the way, when there is room, avoids the crash sooner than braking.
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12. 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.
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13. What should you check about the tire valve stems during the walkaround?
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Answer D: That the stems are not cut, cracked or leaking and the caps are in place
A split stem or a missing cap lets air escape or lets dirt into the valve, and either one can flatten a tire between stops.
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14. Which parts of total stopping distance can a driver shorten simply by staying alert and looking far ahead?
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Answer B: Perception distance and reaction distance
Alertness shortens the time spent recognizing a hazard and moving your foot to the pedal; braking distance depends on speed, weight, brakes and the road surface.
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15. You have just passed another vehicle on a two lane road. What tells you it is safe to return to your lane?
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Answer B: You can see the whole front of that vehicle in your right mirror
Seeing the entire front of the vehicle you passed in your mirror proves you are far enough ahead to move back over without cutting the driver off.
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16. You are stopped in traffic on a steep upgrade behind another truck. How much space should you leave in front?
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Answer A: Enough that you can pull away without rolling back into the vehicle behind you
Room ahead lets you get moving smoothly on a grade instead of having to hold the vehicle perfectly still or roll back toward the traffic behind.
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17. What must be true of the person who performs the annual periodic inspection?
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Answer D: They must meet the federal qualification requirements for an inspector
The inspection has to be done by someone who meets the federal training and experience requirements for inspectors, whoever employs them.
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18. 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.
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19. Which situations call for a mirror check in a commercial vehicle?
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Answer A: Every lane change, turn, merge and tight maneuver
Mirrors must be checked regularly and always before, during and after any movement that changes the path of the vehicle.
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20. How long is a Nebraska Commercial Learner's Permit valid?
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Answer C: One year
Nebraska issues the Commercial Learner's Permit for one year, and it must be held at least fourteen days before a skills test.
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21. You are backing with a helper guiding you and the helper drops out of sight in your mirror. What should you do?
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Answer B: Stop until you can see the helper again
If you cannot see the helper you cannot receive a signal to stop, so the only safe action is to halt until visual contact is restored.
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22. 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.
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23. 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.
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24. You are entering a freeway from a short ramp with a fully loaded trailer. What should you do?
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Answer A: Begin building speed early and wait for a large gap
A loaded vehicle accelerates slowly, so it needs both a running start and a much larger gap than a car would use.
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25. 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.
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26. 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.
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27. Federal rules require a power unit that is not carrying placarded hazardous materials to have a fire extinguisher with which minimum rating?
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Answer A: One rated 5 B:C or more, or two rated 4 B:C or more each
The minimum is a single unit rated 5 B:C or more, or two units of at least 4 B:C each, which is enough to attack a fuel or electrical fire.
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28. 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.
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29. 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.
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30. During a trip you stop for a break. Which items should you check before driving on?
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Answer B: Tires, wheels and rims, brakes, lights, reflectors, electrical connections and cargo securement
Critical items can change during a trip, so each stop is used to recheck the tires, wheels, brakes, lights, connections and cargo.
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31. Under federal rules, what happens to a commercial driver found with any detectable amount of alcohol while operating a commercial vehicle?
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Answer D: The driver is placed out of service for 24 hours
Any measurable alcohol takes a commercial driver off the road for 24 hours, and a concentration of 0.04 percent or more brings a disqualification.
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32. Using the snub braking method on a downgrade, when does the driver release the brakes?
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Answer A: After speed has dropped about 5 mph below the safe speed
The driver brakes firmly to about 5 mph under the chosen safe speed, releases to let the brakes cool, then repeats when the safe speed returns.
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33. 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.
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34. Before starting a trip, what must the driver confirm about the weight of the loaded vehicle?
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Answer A: That it is within the legal gross and axle limits for the route being driven
Overweight vehicles brake poorly, damage tires and suspension components, and can be put out of service at a scale, so weight is checked before the wheels turn.
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35. At highway speed, looking 12 to 15 seconds ahead means looking about how far down the road?
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Answer B: About a quarter of a mile
Twelve to fifteen seconds of travel is roughly a quarter of a mile at highway speed, while the same amount of time is about one block in slow city traffic.
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36. What are the rules for using your turn signal before a turn or lane change?
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Answer A: Signal early, keep the signal on until the turn is finished, then cancel it
An early, continuous signal tells others what you plan to do; cancelling afterward keeps the signal from misleading them.
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37. 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.
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38. Why do cracked spring hangers or badly worn shackles matter?
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Answer A: They allow the axle to shift out of its correct position under the vehicle
Hangers and shackles hold the spring, and therefore the axle, in place, so when they fail the axle can move and the vehicle may become uncontrollable.
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39. An unblocked crate 4 feet long and weighing 900 pounds needs at least how many tiedowns?
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Answer D: One
An article 5 feet or less in length and 1,100 pounds or less in weight is covered by a minimum of one tiedown.
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40. 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.
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41. 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.
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42. A dock crew loads and straps the freight. Who is responsible for the load being legal and secure on the road?
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Answer D: The driver
Even when someone else loads and secures the freight, the driver must inspect it and remains responsible for it while driving.
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43. A car ahead of you keeps drifting within its lane and moving unevenly. What should you assume?
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Answer C: The driver may be distracted, lost or impaired
Unsteady lane keeping is a classic clue to a driver who is not in full control, so the safe response is to keep back and give plenty of room.
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44. Total stopping distance is made up of which parts?
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Answer A: Perception distance, reaction distance and braking distance
The vehicle travels while the hazard is recognized, while the driver moves to the pedal, and again while the brakes slow the vehicle.
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45. 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.
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46. Why is it harder to judge speed and distance at night?
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Answer C: You see much less detail and have fewer reference points
Darkness removes the visual references that the brain uses to estimate distance and closing speed, so drivers routinely misjudge both.
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47. An angry driver has cut in front of you and is now braking hard to provoke you. What is the safest response?
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Answer D: Drop back, avoid eye contact and let the driver go
Giving an aggressive driver space and no response removes the conflict, while any answering gesture invites escalation you cannot control in a heavy vehicle.
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48. What is the danger of letting engine speed climb past the top of the rated rpm range before you shift?
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Answer B: You can damage the engine, so the shift should be made before that point
Every engine has a rated operating range; running above it can cause serious engine damage, so the upshift belongs at the top of that range, not beyond it.
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49. Why should a retarder be switched off when the road is wet, icy or snowy?
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Answer C: It can make the drive wheels skid when traction is poor
A retarder slows the drive wheels only, and on a slippery surface that braking force can break their traction and start a skid.
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50. 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.