Rhode Island 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 Rhode Island test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?
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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.
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2. A commercial driver is convicted of two serious traffic violations within three years. What is the result?
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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.
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3. You drop your phone on the floor of the cab while driving. What do federal rules require?
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Answer A: Leave it, because reaching for it while driving is banned
Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.
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4. A 60 foot combination traveling above 40 mph should hold how many seconds of following distance?
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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.
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5. On a wet road, a commercial driver should reduce speed by roughly how much?
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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.
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6. Why does a heavy vehicle need a much larger gap than a car in order to cross or enter traffic?
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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.
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7. What tells you that an air suspension bag has a problem?
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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.
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8. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
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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.
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9. Which brake lining condition must be reported?
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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.
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10. What is the minimum tread depth required in every major groove of a steering axle tire?
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Answer D: 4/32 inch
Federal rules set a higher tread minimum for front steering tires than for other positions because a steering tire failure is far harder to control.
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11. Why is cargo often covered with a tarp?
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Answer C: To protect people from spilled cargo and to protect the cargo from weather
A cover keeps material from blowing or spilling onto the road and shields the load from rain and sun; it does not replace securement.
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12. What extinguisher rating is required on a vehicle carrying hazardous materials in amounts that need placards?
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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.
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13. Where is a dunnage bag used and how does it work?
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Answer D: Between pieces of cargo inside a van, where it is inflated to take up the gap
A dunnage bag is placed in the void between loads and inflated so the cargo is wedged and cannot move as the vehicle rolls and brakes.
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14. What is the risk when too little weight rests on the drive axles?
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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.
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15. What does the working load limit stamped on a chain or strap describe?
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Answer B: The maximum load the device is rated to hold in normal use
The working load limit is the rated safe capacity for everyday use, deliberately set well below the force that would break the device.
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16. Why is a leak in the exhaust system especially dangerous in cold weather?
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Answer A: Carbon monoxide can build up inside a closed cab
In winter the windows are shut and the heater is running, so exhaust gas that escapes early can reach the driver and cause drowsiness or worse.
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17. You are not certain that your loaded vehicle will clear a low overpass. What should you do?
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Answer A: Take another route rather than risk it
There is no safe way to guess at a clearance, and striking a bridge endangers everyone on and under it, so the only correct choice is a different route.
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18. Under the federal air brake standard, the low air pressure warning must come on before reservoir pressure drops below what level?
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Answer A: Before pressure falls below 60 psi
Federal Motor Vehicle Safety Standard 121 requires the warning to operate while service reservoir pressure is still above 60 psi, which leaves enough air to bring the vehicle to a normal stop.
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19. What speed and gear should be used when backing a large vehicle?
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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.
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20. You have countersteered to correct a rear-wheel skid and the vehicle straightens out. What must you be ready for next?
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Answer D: The vehicle may swing back the other way, so you must steer again to correct it
A vehicle coming out of a skid tends to overshoot and swing in the opposite direction, and the driver must be ready to countersteer a second time.
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21. 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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22. Why does a load of live animals need special attention?
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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.
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23. What must the motor carrier do about a defect listed on a driver vehicle inspection report?
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Answer D: Repair it, or certify that repair is not needed, before the vehicle is dispatched again
A reported defect must be corrected, or certified as not needing correction, and that certification is what the next driver reads before taking the vehicle.
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24. Why does a driver use pull-ups while backing into a tight space?
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Answer C: To pull forward and start the approach again when the angle is going wrong
Stopping, pulling ahead and repositioning fixes a bad angle safely, and there is nothing wrong with needing more than one attempt.
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25. Which wheel or rim condition must be treated as a defect during the walkaround?
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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.
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26. What must be checked on a sliding fifth wheel during the inspection?
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Answer B: That it is locked in position and not so far forward that the trailer can hit the cab
A slider that is unlocked can move under braking, and one set too far forward lets the trailer strike the cab when the tractor turns sharply.
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27. You are unsure whether your vehicle will fit through a narrow gate. What should you do?
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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.
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28. While checking the in-cab gauges after start-up, what should the coolant temperature gauge do?
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Answer C: Rise gradually to the normal operating range
A healthy cooling system warms the engine slowly; a gauge that shoots up or stays cold points to a problem with the thermostat, coolant or sensor.
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29. 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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30. How long must a Rhode Island applicant wait after failing a CDL knowledge exam before retaking it?
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Answer B: Seven days
The Rhode Island DMV commercial learner's permit page requires a seven day wait before a failed commercial knowledge exam can be retaken; exams already passed do not have to be repeated.
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31. You have backed into the same loading bay every week for a year. How often should you still get out and walk to the rear before backing?
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Answer D: Every time, since the area can change while you are away from it
A familiar space is no guarantee; vehicles, pallets, people and overhead obstructions appear between one visit and the next, so you check on every occasion.
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32. Why can an empty truck need a longer stopping distance than a loaded one?
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Answer C: An empty vehicle has less traction, so its wheels lock up more easily
Brakes and tires are designed for a loaded vehicle, and with little weight on the axles the tires grip less and lock sooner.
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33. Within what distance should high beams be lowered at night?
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Answer D: Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following
High beams blind other drivers at close range, so they are lowered at roughly the same distance whether the other vehicle is coming toward you or is ahead of you.
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34. Which driving history makes a Rhode Island applicant ineligible for a CDL?
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Answer A: Three or more moving violations within a 12 month period during the previous two years
The eligibility rules bar an applicant convicted of three or more moving violations within any twelve month period in the two years before the application.
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35. When must a post-trip inspection be made?
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Answer D: At the end of each day the driver operates the vehicle
The post-trip inspection closes out each driving day so that anything found is recorded before the vehicle is handed to the next driver.
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36. A 40 foot straight truck and a 70 foot tractor-trailer make the same right turn. Which needs more room and why?
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Answer B: The tractor-trailer, because the longer the vehicle the farther inside the rear wheels track
Off-tracking grows with the distance between the front and rear axles, so the longer combination cuts the corner much more sharply and needs extra room.
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37. Part of your load stands high enough to hide a rear lamp or a reflector. What must be done?
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Answer B: The load must be moved or extra lamps fitted so the required lights can be seen
Required lamps and reflectors must remain visible; if the cargo blocks them, the load is rearranged or additional lamps are fitted so the vehicle can still be seen.
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38. 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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39. What is axle weight?
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Answer C: The weight carried to the ground by one axle or one set of axles
Axle weight describes how the load is shared among the axles that carry it to the road, not how much the whole vehicle weighs.
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40. What makes a brake hose or air line a defect during the walkaround?
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Answer D: It is cracked, worn, kinked, or rubbing against another part
A chafed or cracked line can burst under pressure and take the braking on that circuit with it, so damage and rubbing points must be corrected.
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41. How far back does Rhode Island look for drug or alcohol convictions when reviewing a CDL application?
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Answer D: Five years
Rhode Island requires that the applicant have no drug or alcohol convictions within the five years before submitting the CDL application.
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42. You press on a drive belt and it deflects far more than the others. What does that suggest?
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Answer C: The belt is too loose and the part it drives may not work properly
A belt with excessive play slips on its pulleys, so the accessory it drives turns too slowly or not at all under load.
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43. While you are driving, what should you do to catch a developing problem with the vehicle?
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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.
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44. After two hours of driving you measure a tire and the pressure reads higher than the cold figure. What should you do?
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Answer B: Nothing, because pressure rises normally as a tire heats up in use
Air expands as the tire heats, so a higher hot reading is expected, and letting air out leaves the tire underinflated once it cools.
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45. Under the federal hours of service rules, how long may a property-carrying driver drive after 10 consecutive hours off duty?
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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.
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46. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?
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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.
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47. 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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48. A brake light lens is cracked and the lamp still lights. How should that be treated?
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Answer B: As a defect, because water can enter and the lamp can dim or fail
A cracked lens lets in water and dirt, which corrodes the socket and dulls the lamp, so it is reported before it becomes a dead brake light.
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49. Federal rules forbid operating a commercial vehicle in which condition?
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Answer C: In a condition likely to cause a crash or a breakdown
A defect that makes a crash or a breakdown likely has to be corrected before the vehicle is driven, not reported at the end of the trip.
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50. An oncoming vehicle drifts across the center line into your lane. What is usually the safest move?
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Answer C: Steer to the right, toward the shoulder if necessary
Moving right keeps you away from the drifting vehicle and off the oncoming side; the other driver may swerve back and hit you if you go left.