Ohio BMV CDL General Knowledge Practice Test 8
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. Loading heavy freight on top of lighter freight has what effect on the vehicle?
Show answer
Answer B: It raises the center of gravity and makes a rollover more likely
A high center of gravity lets the vehicle tip more easily in curves or during a sudden swerve.
-
2. 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.
-
3. A commercial driver is convicted of two serious traffic violations within three years. What is the result?
Show answer
Answer D: Disqualification for 60 days
Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.
-
4. You are unsure whether your vehicle will fit through a narrow gate. What should you do?
Show answer
Answer A: Stop, get out and look, and take another route if the space is not clearly enough
Clearance is never guessed at from the seat; you look at it on foot and go round rather than trying a gap that may be too tight.
-
5. A car is following you far too closely. What is the safest response?
Show answer
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.
-
6. 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.
-
7. An empty van trailer cleared a low overpass on the way in, but on the way back it is loaded. Which statement is true?
Show answer
Answer C: An empty van rides higher than a loaded one, so it needs more clearance than when loaded
Springs compress under load, so an empty trailer is taller; the unloaded trip is the one that can catch a low overhead.
-
8. If an intersection has two lanes marked for left turns, which one should a large vehicle use?
Show answer
Answer D: The right hand of the two turning lanes
The outside turning lane leaves room for the rear of the vehicle to swing without striking a vehicle in the adjacent lane.
-
9. The combined working load limit of the tiedowns on a load must equal at least what share of the cargo weight?
Show answer
Answer C: One half of the cargo weight
Federal securement rules set the aggregate working load limit at no less than half the weight of the article or group of articles being held.
-
10. 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.
-
11. How does a typical escape ramp stop a runaway vehicle?
Show answer
Answer B: With a bed of loose gravel or sand, often on an upgrade
Escape ramps use deep loose material, usually combined with a rising grade, so the vehicle is slowed gradually instead of being stopped by impact.
-
12. Below 40 mph, what following distance does the standard commercial rule of thumb call for?
Show answer
Answer C: One second for every 10 feet of vehicle length
The base rule allows one second of space for each 10 feet of vehicle length while speed stays under 40 mph.
-
13. 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.
-
14. A hard frost has left your vehicle covered in ice. What must be cleared before you drive?
Show answer
Answer D: The windshield, mirrors, lights and reflectors
You must be able to see out and other drivers must be able to see your lights and reflectors, so all of those surfaces have to be cleared.
-
15. What is the correct order for a basic double clutch upshift?
Show answer
Answer B: Release the accelerator and push the clutch, shift to neutral, release the clutch, let engine speed drop, push the clutch again and shift to the higher gear
Double clutching passes through neutral with the clutch released so engine speed can drop to match the next gear before it is engaged.
-
16. Why should you never shift gears while crossing railroad tracks?
Show answer
Answer A: You could miss the gear or stall and be stuck on the tracks
A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.
-
17. 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.
-
18. During the vehicle overview, what should the driver look for on the ground under the vehicle?
Show answer
Answer B: Fresh puddles of oil, coolant, grease or fuel
New stains on the ground are the earliest sign of a leak, so the overview includes a look underneath before anything is opened or started.
-
19. At a stop on a hot day you find a tire that is too hot to touch. What should you do?
Show answer
Answer C: Wait until the tire cools before driving on, and do not let air out of it
A tire that is too hot to touch may be about to fail or catch fire; releasing air only leaves it underinflated once it cools, which makes things worse.
-
20. 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.
-
21. What should you look for on the electrical wiring in the engine compartment?
Show answer
Answer A: Worn, frayed or cracked insulation and loose or corroded connections
Damaged insulation can short a circuit against the frame or engine, which can kill a lamp you depend on or start a fire.
-
22. Which brake lining condition must be reported?
Show answer
Answer C: Linings that are worn thin, loose, cracked or soaked with oil or grease
Linings must have enough material left and must be securely attached and clean, because a thin, loose or contaminated lining cannot deliver its share of braking.
-
23. How can a driver restart the 60 or 70 hour on-duty limit?
Show answer
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.
-
24. How is the fluid level in an automatic transmission usually checked?
Show answer
Answer A: With the engine running, following the procedure in the operator manual
Most automatic transmissions are designed to be checked with the engine running, and the operator manual gives the exact conditions for that vehicle.
-
25. An overpass you have driven under before now has a fresh layer of pavement on the road below it. Why does that matter?
Show answer
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.
-
26. 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.
-
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. 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.
-
29. 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.
-
30. The rear wheels of your vehicle lock during braking and the rear starts to slide sideways. What should you do first?
Show answer
Answer A: Stop braking so the rear wheels can roll again, then steer quickly in the direction you want to go
Locked wheels have no side grip; releasing the brakes restores traction and then countersteering brings the vehicle back into line.
-
31. You are given a ratchet strap with a deep cut along one edge. What should you do?
Show answer
Answer C: Do not use it; a damaged tiedown cannot be relied on to hold its rated load
Cuts, burns, knots and broken stitching weaken a strap far below its marked working load limit, so it must be taken out of service.
-
32. You are moving an oversized load under a permit that requires a pilot vehicle. What is the pilot vehicle there to do?
Show answer
Answer B: Warn other traffic and check the route ahead for clearances and hazards
Escort or pilot vehicles warn approaching traffic and scout the route for low bridges, narrow spots and other hazards that a wide or long load cannot pass.
-
33. 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.
-
34. 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.
-
35. 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.
-
36. You miss a gear while double clutching and the transmission is stuck in neutral. What should you do?
Show answer
Answer B: Return to neutral, release the clutch, bring engine speed to match road speed and try again
Forcing the lever damages the gears; matching the engine speed to the road speed lets the gear engage cleanly on the next try.
-
37. 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.
-
38. 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.
-
39. How should a commercial driver treat the speed posted for a curve?
Show answer
Answer B: As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed
Posted curve speeds are based on passenger vehicles in good conditions, and a tall or heavy load can roll over well below that speed.
-
40. A doctor prescribes you a medicine that can cause drowsiness. What should you do?
Show answer
Answer A: Tell the doctor what you drive and not drive while affected
Both prescription and over the counter medicines can make a driver unsafe, so the medical professional must know the job and the driver must stay out of the seat while affected.
-
41. What extinguisher rating is required on a vehicle carrying hazardous materials in amounts that need placards?
Show answer
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.
-
42. A sign before a long descent shows 6 percent. What does that number tell you?
Show answer
Answer A: How steep the grade ahead is
Percent grade is the drop in feet for every hundred feet of road, so the higher the number the faster speed will build and the lower the gear you need.
-
43. How long is an Ohio Commercial Learner Permit, or CLP, valid?
Show answer
Answer A: 12 months
An Ohio Commercial Learner Permit is valid for 12 months from issuance.
-
44. Under federal rules, what happens to a commercial driver found with any detectable amount of alcohol while operating a commercial vehicle?
Show answer
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.
-
45. 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.
-
46. What are you checking when you look at the batteries during the engine compartment inspection?
Show answer
Answer D: That they are securely mounted, the connections are tight and free of corrosion, and the caps are in place
Loose or corroded batteries can fail or short out, so the mount, cables, terminals and vent caps are all part of the check.
-
47. Your windshield washer reservoir is empty and rain and road spray are expected. What should you do?
Show answer
Answer D: Fill it before the trip, because you need the washers to keep the windshield clear
Wipers alone smear the film of oil and grit thrown up by traffic, so the washers are part of keeping a usable view of the road.
-
48. At what time of day do drowsy driving crashes occur most often?
Show answer
Answer A: Between midnight and 6 a.m.
The body clock makes people sleepiest in the early morning hours, which is when most fatigue-related crashes happen.
-
49. Most rollovers of loaded trucks on exit and entrance ramps happen for which reason?
Show answer
Answer B: The ramp was taken faster than the load could tolerate
A posted ramp speed is set for cars, and a loaded trailer with a high center of gravity can roll at a speed a car would take easily.
-
50. Why does a heavy vehicle need a much larger gap than a car in order to cross or enter traffic?
Show answer
Answer C: Because it accelerates slowly and needs far more road and time to clear the intersection
Slow acceleration combined with the length of the vehicle means a gap that would feel comfortable in a car is nowhere near enough.