Nebraska DMV CDL General Knowledge Practice Test 8
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. Who must sign a driver vehicle inspection report?
Show answer
Answer D: The driver who prepared it
The report is the driver statement about the condition of the vehicle at the end of the day, so the driver signs it.
-
2. On a tractor with a sliding fifth wheel, what does moving the fifth wheel forward do?
Show answer
Answer A: Puts more of the trailer weight onto the steering axle
Moving the coupling point forward transfers weight from the drive axles to the steering axle, which is how a driver corrects a drive axle that is over the limit.
-
3. What is checked about the engine cooling system during the engine compartment inspection?
Show answer
Answer C: That the coolant level is adequate and the radiator and hoses are not leaking
A low coolant level or a leaking hose leads to overheating, which can stop the vehicle in a place where stopping is dangerous.
-
4. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?
Show answer
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.
-
5. In a vehicle with a manual transmission, when should the clutch be pushed in during a normal stop?
Show answer
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.
-
6. Which set of maneuvers makes up the basic control skills part of the commercial driving test?
Show answer
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.
-
7. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?
Show answer
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.
-
8. What does mountain driving demand that flat country driving does not?
Show answer
Answer D: Lower gears and constant allowance for gravity
In the mountains gravity works for you on the climb and against you on the descent, so gear selection and speed control matter far more than on level road.
-
9. Besides the hours when the law requires them, when should headlights be switched on?
Show answer
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.
-
10. What is the purpose of the torque rods or radius rods you check on the suspension?
Show answer
Answer A: They hold the axle in alignment with the frame under braking and acceleration
Torque rods resist the twisting and fore and aft forces on the axle, so a cracked or missing rod lets the axle move out of alignment.
-
11. Why should a driver avoid shifting gears in the middle of a turn at an intersection?
Show answer
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.
-
12. You are told a posted bridge ahead has a weight limit lower than your gross weight. What must you do?
Show answer
Answer C: Take a route that avoids it, because a posted limit is a legal limit
A posted structure limit must be obeyed exactly as any other weight limit, so a heavier vehicle has to be routed around it.
-
13. What should you do with the previous driver vehicle inspection report before starting your trip?
Show answer
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.
-
14. How should the steering wheel be held when driving a large vehicle?
Show answer
Answer D: Firmly with both hands, placed on opposite sides of the wheel
Both hands on opposite sides give the leverage and control needed if a tire drops off the pavement or the wheel is jolted.
-
15. Why does the manual insist on a firm grip with both hands on opposite sides of the steering wheel?
Show answer
Answer A: A hard bump can pull the wheel out of a loose grip
Hitting a curb or a deep pothole can jerk the wheel violently, and only a firm two-handed grip keeps the vehicle under control when that happens.
-
16. A driver is tailgating you, honking and making gestures. What is the best response?
Show answer
Answer A: Do not make eye contact, ignore the gestures and give the driver room to get past
Engaging an aggressive driver only escalates the situation; the safest move is to stay calm, avoid eye contact and let the driver get by.
-
17. How is a shipping container normally secured when it is carried on a special container chassis?
Show answer
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.
-
18. What are you checking when you pull the engine oil dipstick during the pre-trip?
Show answer
Answer A: That the oil level is within the safe operating range marked on the stick
The dipstick shows whether there is enough oil to lubricate and cool the engine, and a level outside the safe range must be corrected before driving.
-
19. How do you confirm that the coupling is locked before pulling out of the yard?
Show answer
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.
-
20. During the engine compartment check, which leaks are you looking for?
Show answer
Answer D: Fuel, coolant, engine oil, power steering fluid and battery fluid
Every fluid in the compartment matters, because a fuel leak is a fire risk and a loss of coolant, oil, steering fluid or electrolyte can disable the vehicle.
-
21. A chain rated at 6,600 pounds is fitted with a hook rated at 4,700 pounds. What is the working load limit of that assembly?
Show answer
Answer A: 4,700 pounds, the rating of the weakest part
An assembly is only as strong as its weakest component, so hooks, binders and links all count and the lowest rating governs.
-
22. The coolant temperature gauge climbs above its normal range on a long grade. What is the correct response?
Show answer
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.
-
23. Why must the driver of a large vehicle keep it centered in its lane?
Show answer
Answer B: The vehicle needs the full width of the lane
A commercial vehicle is close to lane width already, so any drift takes part of the vehicle into the next lane or onto the shoulder.
-
24. Besides allowing the move at all, what does an oversize load permit usually set out?
Show answer
Answer C: The route to be followed, the hours of travel allowed and the warning equipment needed
Permits for oversize movements normally name the roads that may be used, restrict the times of travel, and list the flags, signs and escorts required.
-
25. How many questions does the Nebraska CDL general knowledge test contain, and how many may be missed?
Show answer
Answer A: 50 questions, with no more than 10 missed
Nebraska's general knowledge test has 50 questions and the applicant may miss no more than 10, matching the 80 percent minimum the state applies to all written tests.
-
26. At the scale your tractor drive axles are overweight while the trailer axles have room. Sliding the trailer tandems forward will do what?
Show answer
Answer C: Move weight off the drive axles and onto the trailer axles
Sliding the trailer tandems forward brings the rear support closer to the load, so the trailer axles pick up more weight and the drive axles carry less; sliding them rearward does the opposite.
-
27. A tire may be regrooved only when what is true?
Show answer
Answer B: It carries a marking from the manufacturer showing that it is regroovable
Only casings built with extra rubber under the tread and marked regroovable by the manufacturer may be cut, because others would be grooved into the belts.
-
28. What must be checked about the cargo doors and any tarpaulin before a trip?
Show answer
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.
-
29. You stop to check the load. Which set of things are you looking at?
Show answer
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.
-
30. What does safe practice require of a commercial driver who wants to eat, drink or read a delivery note?
Show answer
Answer B: Handle it before or after driving, not while moving
Anything that takes hands, eyes or attention away from the task belongs outside the driving time, not inside it.
-
31. What tells you that an air suspension bag has a problem?
Show answer
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.
-
32. Experienced commercial drivers scan the road ahead by roughly how much travel time?
Show answer
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.
-
33. What does the driver check in the final step of the seven-step inspection?
Show answer
Answer A: Hydraulic brake leaks where those brakes are fitted, then the parking brake and the service brakes
The last step is done with the engine started: test for hydraulic leaks on vehicles with hydraulic brakes, then prove that the parking brake holds and that the service brakes stop the vehicle.
-
34. What should you do before backing into a space you have not used before?
Show answer
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.
-
35. You are asked to drive a truck loaded with enough hazardous materials to require placards. What must you have?
Show answer
Answer C: A hazardous materials endorsement on your commercial driver license
Driving a vehicle that must be placarded requires the H endorsement, which involves a separate knowledge test and a security background check.
-
36. Besides slowing down, which technique most reduces the risk of a skid on a snow covered road?
Show answer
Answer B: Make every steering, braking and speed change gradual
Traction is limited on snow, and sudden inputs demand more grip than the surface can supply, so smoothness is what keeps the tires attached to the road.
-
37. You are loading a flatbed that has no sides or bulkheads. How must the cargo be held?
Show answer
Answer D: By tiedowns, blocking or bracing, since there are no walls to keep it from shifting or falling off
Open decks depend entirely on securement devices; every article must be tied down or otherwise immobilized so it cannot move, spill or fall.
-
38. An unblocked article is 15 feet long. What is the minimum number of tiedowns?
Show answer
Answer B: Three
Two tiedowns cover the first 10 feet and one more is added for each further 10 feet or any part of it, so 15 feet needs three.
-
39. Which wheel or rim condition must be treated as a defect during the walkaround?
Show answer
Answer C: Cracks, illegal welded repairs, or missing and loose lug nuts
Cracked or welded rims and missing or loose fasteners can let a wheel separate from the vehicle and must be corrected before driving.
-
40. What is generally the safest speed in dense but freely moving highway traffic?
Show answer
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.
-
41. What color must the clearance and side marker lamps and reflectors at the front of a trailer be?
Show answer
Answer A: Amber
Amber marks the front and the forward part of the sides of a vehicle, while red marks the rear, so another driver can tell which way the vehicle is facing.
-
42. A company mechanic serviced your truck this morning and signed the work order. Do you still have to inspect the vehicle?
Show answer
Answer B: Yes, the driver is still responsible for being satisfied the vehicle is safe
Shop work does not transfer the duty; the driver who takes the vehicle out remains responsible for being satisfied it is in safe operating condition.
-
43. An unblocked article is 8 feet long and weighs 900 pounds. How many tiedowns does the federal rule require?
Show answer
Answer B: Two
Only an article that is 5 feet or shorter and 1,100 pounds or lighter can be held with a single tiedown; anything longer than 5 feet needs at least two whatever it weighs.
-
44. How do you avoid the sharp lurch that comes at the very end of a stop in a heavy vehicle?
Show answer
Answer A: Ease off the brake pressure just before the vehicle actually comes to rest
A smooth stop is finished by reducing pedal pressure as the vehicle settles, so the suspension does not rock the cab and the load forward.
-
45. When should a lower gear be selected for a long downgrade?
Show answer
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.
-
46. Your brakes have failed and you decide to use the parking brake to slow down. Why should you hold the release button or lever while doing so?
Show answer
Answer D: So you can release the brake at once if the wheels lock and the vehicle starts to skid
The parking brake can lock the wheels; keeping your hand on the release lets you let go the moment a skid starts and regain control.
-
47. Why must cargo also be held down against vertical movement and not only against sliding?
Show answer
Answer D: Because a load that bounces can jump the blocking and slacken its own tiedowns
Rough road makes an unrestrained article lift; every bounce lets it move a little and works the tiedowns loose until nothing is holding it.
-
48. Where should a trailer be dropped, and what else does the driver do before pulling out from under it?
Show answer
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.
-
49. Why should the mirrors be checked repeatedly while you make a tight turn?
Show answer
Answer C: To watch the rear of the vehicle clear other vehicles and objects
In a long vehicle the rear wheels cut inside the path of the front wheels, so only the mirrors show whether the rear is clearing curbs, poles and other vehicles.
-
50. May a Nebraska CDL holder enter a traffic diversion program to avoid a conviction for a moving violation?
Show answer
Answer B: No, a CDL holder may not use diversion for any traffic citation except a parking violation
Nebraska prohibits CDL holders from entering a traffic diversion program to avoid a conviction for any traffic citation other than a parking violation.