Nevada DMV CDL General Knowledge Practice Test 2
Test 2 of 5. Pick an answer for each question to see if it is right and why; your score appears at the end. You need 40 correct answers to pass, the same ratio as the real Nevada test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. Besides being uncomfortable, what can a series of hard, jerky brake applications do to a loaded combination?
Show answer
Answer A: Shift the load and push the trailer out of line behind the tractor
Sudden, uneven braking can move cargo forward and upset the alignment of a trailer, which is why stops should be made smoothly.
-
2. Where should a driver expect fog to form first?
Show answer
Answer D: In low ground, near water and in valleys
Cool moist air settles in low places, so fog patches appear in hollows, river valleys and near lakes before they appear anywhere else.
-
3. You are inspecting the vehicle alone and need to confirm that the stop lights work. Which method is correct?
Show answer
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.
-
4. What is checked in step six of the seven-step method?
Show answer
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.
-
5. What speed and gear should be used when backing a large vehicle?
Show answer
Answer B: As slowly as possible, in the lowest reverse gear
Backing slowly in the lowest reverse gear keeps the vehicle under precise control and leaves time to correct the path.
-
6. What is the best practice when fog is thick enough to hide the road ahead?
Show answer
Answer B: Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves
The safest choice in heavy fog is not to be driving in it, and if you are already in it your speed has to come down before your visibility does.
-
7. Why does a load of live animals need special attention?
Show answer
Answer D: The animals move and lean, so the center of gravity shifts and the vehicle can be pushed off balance in a turn
A live load will not stay where it is put, and that movement changes the balance of the vehicle exactly when a curve is loading it most.
-
8. 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?
Show answer
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.
-
9. What should a driver assume about the height posted at a bridge or an overpass?
Show answer
Answer B: That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows
Resurfacing and packed snow raise the road under the structure, so the real clearance can be lower than the posted figure.
-
10. What is normally required in order to move an over-width or over-length load?
Show answer
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.
-
11. Total stopping distance is made up of which parts?
Show answer
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.
-
12. An oncoming vehicle at night has bright headlights that are making it hard to see. What should you do?
Show answer
Answer B: Look toward the right edge of your lane and avoid looking directly at the lights
Looking at the right edge of the road keeps your eyes off the glare while you stay in your lane; glare can leave you nearly blind for several seconds.
-
13. 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?
Show answer
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.
-
14. Two vehicles of exactly the same length make a right turn, one gently and one very tightly. What is the effect on off-tracking?
Show answer
Answer A: Turning more sharply increases off-tracking, so the tight turn needs more room
Off-tracking depends on both the length of the vehicle and the sharpness of the turn; a tighter corner brings the rear wheels further inside the path of the front wheels.
-
15. Why does the commercial driver manual tell you to look far down the road instead of only at the vehicle ahead?
Show answer
Answer D: So you can adjust smoothly instead of braking hard at the last moment
A heavy vehicle cannot react quickly, so early information lets you slow gradually rather than make a sudden stop or swerve.
-
16. After starting a trip, when must a driver first re-inspect the cargo and the devices holding it?
Show answer
Answer A: Within the first 50 miles
Federal rules require a check of the load and its securement within the first 50 miles, because settling and vibration loosen straps and chains early in a trip.
-
17. How should a driver use brakes fitted with an antilock system during an emergency stop?
Show answer
Answer C: Brake as usual and keep enough pressure to stay in control while steering around the hazard
The system only works when the brakes are applied hard enough for it to act, so the driver keeps pressure on and steers while the system prevents lockup.
-
18. What is the correct order for a double clutch downshift?
Show answer
Answer D: Release the accelerator and push the clutch to reach neutral, release the clutch and press the accelerator to raise engine speed, then push the clutch again and select the lower gear
A lower gear turns faster than the one being left, so engine speed has to be raised in neutral before that gear will engage cleanly.
-
19. How does a front tire failure usually feel to the driver?
Show answer
Answer D: The steering suddenly becomes heavy and pulls to one side
A failed front tire loads the steering and makes the wheel feel heavy, while a rear tire failure shows up as the back end swaying.
-
20. Under the federal hours of service rules, how long may a property-carrying driver drive after 10 consecutive hours off duty?
Show answer
Answer D: Up to 11 hours, and only within a 14 hour window that starts when the driver comes on duty
The federal limit is 11 hours of driving after 10 consecutive hours off duty, and all of that driving has to fall inside a 14 hour window.
-
21. A 60 foot combination traveling above 40 mph should hold how many seconds of following distance?
Show answer
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.
-
22. Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?
Show answer
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.
-
23. Your speedometer stops working during the pre-trip check. How should it be treated?
Show answer
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.
-
24. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?
Show answer
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.
-
25. Which lights should be used in fog, by day or by night?
Show answer
Answer A: Low beams and fog lights, together with the four-way flashers
High beam light bounces back off the water droplets and makes seeing worse, while low beams, fog lights and flashers help you see and help others see you.
-
26. What is the coupling device weight rating on a vehicle?
Show answer
Answer A: The most weight that the coupling on the vehicle is rated to pull
The coupling device rating is a limit on how much weight the coupling may tow, and it is one of the ratings that has to be respected when a combination is loaded.
-
27. Which combination of warning devices meets the requirement for a stopped commercial vehicle?
Show answer
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.
-
28. You are pulling away from a curb in a 65 foot combination. Besides traffic, what must you watch?
Show answer
Answer B: The trailer wheels, which stay close to the curb and can strike it or an object on it
Because of off-tracking, the rear wheels follow a tighter path than the front, so they stay near the curb while the cab is already out in the lane.
-
29. What minimum age does Nevada set for driving an over-length combination vehicle of 70 feet?
Show answer
Answer A: 25 years
Nevada requires an applicant to be at least 25 years old to receive the endorsement for an over-length combination vehicle of 70 feet.
-
30. After coupling, where should the fifth wheel release handle be?
Show answer
Answer A: In the locked position with the safety latch in place
The handle must be pushed in and latched, because a handle left out means the jaws can open and release the trailer while you are driving.
-
31. 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.
-
32. 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?
Show answer
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.
-
33. 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.
-
34. Dry bulk tanks call for extra caution mainly because of what?
Show answer
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.
-
35. What extra check does Nevada require before accepting entry-level driver training results from a school in the state?
Show answer
Answer B: The school must appear on the federal Training Provider Registry and also hold a Nevada DMV business license
Nevada tells applicants to verify that a school listed on the federal Training Provider Registry also holds a Nevada DMV business license, because otherwise the DMV may refuse the training results.
-
36. What is the danger of letting engine speed climb past the top of the rated rpm range before you shift?
Show answer
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.
-
37. Two tires in a dual set have noticeably different diameters. Why is that a problem?
Show answer
Answer C: The larger tire carries more than its share of the load and can be overloaded
The taller tire touches the road first and takes most of the weight, so it runs overloaded and hot while the smaller one does little work.
-
38. At a rest area you find that the load has shifted although the straps still feel tight. What should you do?
Show answer
Answer C: Correct the load before driving on, since a shifted load is no longer secure
Movement means the securement has already failed once, and a load that has shifted can shift again, so it is put right before the vehicle moves.
-
39. What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?
Show answer
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.
-
40. 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.
-
41. What are you looking for on the brake drums during the walkaround?
Show answer
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.
-
42. Why should a driver avoid stopping partway up a snow covered hill?
Show answer
Answer D: You may not get moving again and could slide backwards
On a slippery grade the drive wheels may simply spin when you try to restart, leaving the vehicle stuck across the road or sliding back down it.
-
43. Where on the road are you most likely to find ice in cold weather?
Show answer
Answer B: On bridges, overpasses and shaded stretches, which freeze before the rest of the road
Bridges and overpasses lose heat from above and below, and shaded areas get no sun, so they ice over first and stay icy longest.
-
44. An unblocked crate 4 feet long and weighing 1,500 pounds needs at least how many tiedowns?
Show answer
Answer A: Two
A short article that weighs more than 1,100 pounds requires at least two tiedowns even though it is under 5 feet long.
-
45. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
Show answer
Answer C: After 8 cumulative hours of driving time
Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.
-
46. A vehicle becomes unsafe while you are already on the road. What does the federal rule allow?
Show answer
Answer A: Continuing only to the nearest place where repairs can safely be made
If stopping where you are would be more dangerous than moving, the rule allows you to reach the nearest place where the vehicle can safely be repaired, and no further.
-
47. 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?
Show answer
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.
-
48. 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.
-
49. 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.
-
50. What frame defects are you looking for during the walkaround?
Show answer
Answer A: Cracks, bends or broken cross members
The frame carries the whole load, so cracked or bent rails and broken cross members are serious structural defects.