Oregon DMV CDL General Knowledge Practice Test 5
Test 5 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 Oregon test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. How are the extra gears of a multi-speed rear axle or auxiliary transmission usually controlled?
Show answer
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.
-
2. You must steer hard around an obstacle at highway speed. What is the correct technique?
Show answer
Answer B: Avoid braking while turning, turn only as far as needed, and countersteer as soon as the obstacle is passed
Braking during a hard steering input can lock the wheels and start a skid, and turning back at once keeps the vehicle from running off the far side of the road.
-
3. How does the working load limit of a tiedown relate to the force that would break it?
Show answer
Answer B: The working load limit is a fraction of the breaking strength and is the figure you use
The working load limit is set well below the point at which the device would fail, and securement is always calculated from the working load limit, never from breaking strength.
-
4. When should a driver select the gear for a long, steep downgrade?
Show answer
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.
-
5. 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.
-
6. What must the driver check about the seat belt during the inspection?
Show answer
Answer A: That it is securely mounted, adjusts properly and is not ripped or frayed
A belt only restrains the driver if its anchorage is sound and the webbing is intact, so mounting and condition are both checked.
-
7. Which items belong to the trailer part of the walkaround inspection?
Show answer
Answer D: Landing gear, doors, tires, wheels, lights, reflectors, frame and cargo securement
The trailer has its own running gear, lighting, structure and load, and all of it is the responsibility of the driver pulling it.
-
8. In Oregon, violating a federal out-of-service order while holding a CDL leads to disqualification for how long on a first violation?
Show answer
Answer A: At least 180 days
Oregon's CDL rules disqualify a driver for at least 180 days on a first violation of an out-of-service order, rising to 1 year for a second violation and 3 years for a third or later violation within ten years.
-
9. On a wet road, a commercial driver should reduce speed by roughly how much?
Show answer
Answer C: By about one third
Cutting speed by roughly a third, for example from 55 to about 35 mph, restores a margin for the traction lost on a wet surface.
-
10. A CDL holder convicted three or more times within three years of texting while operating a CMV in Oregon faces disqualification for how long?
Show answer
Answer B: 120 days
Oregon's CDL manual disqualifies a driver for 120 days after three or more texting convictions within three years while operating a CMV, the higher of the two escalation steps in that penalty.
-
11. You want to check whether a tire on your truck is properly inflated. What is the correct method?
Show answer
Answer A: Measure the pressure with a tire gauge
Only a tire gauge tells you the actual pressure; a tire can look and sound normal while being badly underinflated.
-
12. Your vehicle begins to hydroplane on a wet road. What should you do?
Show answer
Answer B: Release the accelerator and push in the clutch so the wheels can turn freely and regain grip
Hydroplaning tires are riding on water; slowing without braking lets them settle back onto the road and grip again.
-
13. How much sleep does a typical adult driver need each day to stay properly alert?
Show answer
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.
-
14. What must a written driver vehicle inspection report cover at the end of the day?
Show answer
Answer C: Any defect or deficiency that would affect safety or could cause a mechanical breakdown
The report identifies the vehicle and lists defects that affect safe operation or could lead to a breakdown, so they are repaired before the next trip.
-
15. Why must the steering wheel be moved only a small amount at a time while backing?
Show answer
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.
-
16. The engine oil pressure gauge falls toward zero while you are driving. What should you do?
Show answer
Answer C: Stop as soon as it is safe to do so and shut the engine down
Loss of oil pressure destroys an engine in a very short time, so the correct response is to stop and shut down rather than to drive on.
-
17. A car that passed you on the right slows and stays alongside your trailer. What is the best response?
Show answer
Answer D: Ease off the accelerator so the car can move clear
A vehicle sitting beside a trailer is in a blind area and has nowhere to go if you need the lane, so the safest fix is to let it get ahead or behind.
-
18. Why should you avoid using your lights to tell a following driver that it is safe to pass you?
Show answer
Answer B: You may misjudge the gap and the driver will act on your signal
The manual warns against signaling others to pass, because the responsibility for a head-on crash then rests on a judgment you could easily get wrong.
-
19. When turning left, what should a driver of a long vehicle do before beginning the turn?
Show answer
Answer B: Reach the center of the intersection so the rear wheels clear the corner
The rear wheels follow a tighter path than the front, so the vehicle must reach the center of the intersection before the turn begins.
-
20. On a set of dual tires, which condition must be reported as a defect?
Show answer
Answer D: The two tires are touching each other or rubbing on part of the vehicle
Duals that touch each other or the vehicle overheat and wear quickly, so they must be separated by proper spacing and inflation before driving.
-
21. Why is a quick lane change particularly risky with a load of hanging meat or of livestock?
Show answer
Answer A: The load swings or leans and can keep pushing the trailer after you straighten out
A swinging or leaning load keeps moving after the vehicle has finished the maneuver, so its momentum acts on the trailer at the worst moment.
-
22. 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.
-
23. 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.
-
24. What should be checked about the power steering system in the engine compartment?
Show answer
Answer D: That the fluid level is correct and the hoses and pump are not leaking
Losing power steering fluid means losing steering assistance, which can happen suddenly and makes a heavy vehicle very hard to turn.
-
25. What do you check about the fire extinguisher during the pre-trip?
Show answer
Answer C: That it is securely mounted, charged and that you know how to operate it
An extinguisher must be held in its bracket, show a charged gauge and be understood by the driver, because a fire leaves no time to learn.
-
26. The shipper hands you the placards for a load that needs them. Who puts them on the vehicle?
Show answer
Answer C: The driver, who must also make sure they are the correct ones and are readable
The shipper supplies the placards, but it is the driver who must place them on the vehicle and confirm that they match the load and can be read.
-
27. 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.
-
28. 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.
-
29. Which shock absorber condition is a defect?
Show answer
Answer C: A shock that is leaking, broken or disconnected at either mounting
A shock that has lost its fluid or its mounting no longer damps the suspension, so the wheel bounces and loses contact with the road.
-
30. Your vehicle is stopped just past a hill or curve that hides it from approaching traffic. How should the warning devices be adjusted?
Show answer
Answer A: Move the rearmost device farther back, up to 500 feet, so drivers are warned before the obstruction
When a hill or curve blocks the view, the farthest device is moved back beyond the obstruction so approaching drivers see the warning in time.
-
31. When must a driver first inspect the cargo and its securement devices?
Show answer
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.
-
32. What is the driver looking for when the exhaust system is inspected?
Show answer
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.
-
33. Your load projects more than 4 feet beyond the rear of the vehicle. How must the projecting end be marked?
Show answer
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.
-
34. Cargo carried inside the cab must never do which of these?
Show answer
Answer C: Block the driver view, restrict arm or leg movement, or block an emergency exit
Anything inside the cab must leave the driver a clear view, free movement of the arms and legs, and an unobstructed way out of the vehicle.
-
35. 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.
-
36. Why is driving much slower than the rest of the traffic dangerous?
Show answer
Answer B: Other drivers must keep passing you, which creates conflicts
Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.
-
37. Which steering system findings count as defects during the inspection?
Show answer
Answer C: Bent, loose or broken column parts, arms, drag links or tie rods, and missing nuts, bolts or cotter keys
Every joint and fastener between the steering wheel and the tires carries the driver commands, so looseness or a missing retainer can end in a complete loss of steering.
-
38. 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.
-
39. A commercial vehicle stops on the shoulder of an undivided two-lane road that carries traffic in both directions. Where do the warning devices go?
Show answer
Answer B: Within 10 feet of the vehicle, plus 100 feet to the front and 100 feet to the rear
On a two-way road the devices must mark the vehicle itself and warn traffic approaching from each direction, and they must be in place within ten minutes.
-
40. 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.
-
41. A load overhangs the rear of the trailer. What must the driver check before leaving?
Show answer
Answer D: That the overhang is marked as required, with flags or lamps as conditions demand
A projecting load has to be made visible to other drivers, with flags in daylight and lamps when lights are required, so nobody runs into what they cannot see.
-
42. You are stopped in a line of traffic behind a car. How much space should you leave in front of you?
Show answer
Answer C: Enough to see where the rear tires of that car meet the road
That amount of space lets you pull around the vehicle ahead if it stalls and absorbs some of the shock if you are struck from behind.
-
43. While you are driving, what should you do to catch a developing problem with the vehicle?
Show answer
Answer A: Check the gauges regularly and pay attention to unusual sounds, smells or vibrations
Inspection continues during the trip: gauges, mirrors and your senses can reveal a problem long before a warning light does.
-
44. What is the risk when too little weight rests on the drive axles?
Show answer
Answer A: Poor traction, so the drive wheels spin easily on wet or slippery surfaces
Traction depends on weight pressing the driving tires onto the road, so a light drive axle spins on wet, snowy or loose surfaces.
-
45. Which parts of total stopping distance can a driver shorten simply by staying alert and looking far ahead?
Show answer
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.
-
46. You can see a crack in a brake drum that runs across more than half the width of the friction surface. What does this mean?
Show answer
Answer C: The drum is defective and must be repaired before the vehicle is driven
Cracks longer than half the width of the friction area mean the drum can break apart under braking heat and must be replaced.
-
47. Before raising the hood to inspect the engine compartment, what should you do?
Show answer
Answer B: Shut off the engine, set the parking brake and chock the wheels if needed
The engine compartment is inspected with the engine off and the vehicle secured so nothing can move or turn while your hands are inside.
-
48. What is the minimum age for an Oregon CDL limited to intrastate commerce?
Show answer
Answer B: 18 years
Oregon allows a commercial driver license at 18 for driving that stays entirely within the state.
-
49. During a right turn in a tractor-trailer, what are you looking for in the right hand mirror?
Show answer
Answer B: Whether the trailer will clear the curb and whether anything has moved alongside you
The right mirror is what tells you how close the trailer wheels are running to the curb and whether a vehicle or a cyclist has slipped into the space on your right.
-
50. How should speed and gears be handled when approaching a curve?
Show answer
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.