Georgia DDS CDL General Knowledge Practice Test 7

  • Questions50
  • Correct to pass40
  • Passing score80%
  • Minimum age18 years

50 questions. Pick an answer to see if it is right and why; you need 40 correct answers to pass.

  1. 1. 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.

  2. 2. When a helper guides you while backing, what should be agreed on before you start?

    Show answer

    Answer D: A set of hand signals, especially the signal that means stop

    The driver and helper must agree on signals in advance, above all the stop signal, because they usually cannot hear each other.

  3. 3. 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.

  4. 4. What information does an inspection decal on a commercial vehicle carry?

    Show answer

    Answer B: The date of the inspection, where the inspection report is kept, and information identifying the vehicle

    The decal shows when the inspection was done, the name and address of the entity that holds the inspection report, and which vehicle it belongs to, so an officer can confirm the inspection at a glance.

  5. 5. 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.

  6. 6. What is the minimum tread depth for tires in positions other than the steering axle?

    Show answer

    Answer A: 2/32 inch

    Drive and trailer tires must keep at least 2/32 inch of tread in a major groove, measured away from tie bars and fillets.

  7. 7. Why can an empty truck need a longer stopping distance than a loaded one?

    Show answer

    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.

  8. 8. 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.

  9. 9. 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.

  10. 10. Around a tractor-trailer, where are the blind areas that other drivers most often sit in unseen?

    Show answer

    Answer A: Along the right side and directly behind the trailer

    The blind areas to the right of the cab and behind the trailer are the largest, which is why other drivers should never linger there.

  11. 11. 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.

  12. 12. How do you test for leaks in a hydraulic brake system during the pre-trip inspection?

    Show answer

    Answer A: Pump the pedal three times, then hold firm pressure for five seconds and make sure the pedal does not move

    If the pedal sinks while you hold pressure, fluid is escaping or air is in the lines, and the vehicle must not be driven until the problem is repaired.

  13. 13. Why should a retarder be switched off when the road is wet, icy or snowy?

    Show answer

    Answer C: It can make the drive wheels skid when traction is poor

    A retarder slows the drive wheels only, and on a slippery surface that braking force can break their traction and start a skid.

  14. 14. Why does a load need to be balanced from side to side?

    Show answer

    Answer B: Because a heavy side raises the rollover risk and can overload the tires and springs on that side

    An uneven load tips the balance of the vehicle in curves and pushes the tires and suspension on the loaded side past their rating.

  15. 15. Why is braking while in a curve dangerous in a heavy vehicle?

    Show answer

    Answer A: The wheels lock more easily and the vehicle can skid

    Tires already using their grip to turn have little left for braking, so hard braking in a curve locks the wheels; slow down before the curve instead.

  16. 16. Which document must be available to show that the annual inspection was carried out?

    Show answer

    Answer C: The inspection report or a copy of it, or a decal displayed on the vehicle

    Proof of the periodic inspection travels with the vehicle, either as the report itself or as the decal fixed where an inspector can see it.

  17. 17. Apart from the risk of stalling, why is rolling backwards when starting on an upgrade so serious in a heavy vehicle?

    Show answer

    Answer D: You can strike the vehicle behind you, which is often much closer than you think

    You cannot see how close the vehicle behind has stopped, and even a short roll back is enough to hit it.

  18. 18. 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.

  19. 19. 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.

  20. 20. While double clutching, what goes wrong if you take too long between the two clutch movements?

    Show answer

    Answer A: Engine speed falls too far and the gear becomes hard or impossible to engage

    Double clutching only works while engine speed and road speed still match; a slow shift lets rpm drop away and the gear will not go in.

  21. 21. You are on a freeway and see brake lights come on in several vehicles far ahead of you. What should you do?

    Show answer

    Answer A: Ease off the accelerator and get ready to slow down

    Brake lights well ahead are an early warning that traffic is slowing, and acting on them gives a heavy vehicle the room it needs.

  22. 22. In Georgia, what happens if the license to drive a personal vehicle is revoked, cancelled or suspended?

    Show answer

    Answer D: No hardship license may be obtained to operate a commercial motor vehicle

    Georgia does not allow a hardship license for operating a commercial motor vehicle when the driver's personal vehicle license has been revoked, cancelled or suspended.

  23. 23. 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.

  24. 24. 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.

  25. 25. You have a part load that fills only a third of a long trailer. How should it be placed?

    Show answer

    Answer C: Spread out and centerd side to side, so the weight sits over the axles

    A part load is spread over as much of the floor as possible and kept centerd, so no axle is overloaded and the vehicle stays balanced from side to side.

  26. 26. 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.

  27. 27. 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.

  28. 28. Where are regrooved, recapped or retreaded tires not allowed on a truck or truck tractor?

    Show answer

    Answer C: On the front steering wheels

    Regrooved and retreaded tires are prohibited on the front wheels of a truck or truck tractor because a steering tire blowout is extremely difficult to manage.

  29. 29. 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.

  30. 30. What does gross vehicle weight mean, as opposed to gross vehicle weight rating?

    Show answer

    Answer B: The actual weight of the single vehicle plus everything it is carrying

    Gross vehicle weight is what the vehicle actually weighs at that moment; the rating is the maximum the manufacturer allows it to weigh.

  31. 31. Some commodities have their own detailed securement rules on top of the general ones. Which list is made up of such commodities?

    Show answer

    Answer C: Logs, metal coils, paper rolls, concrete pipe and crushed vehicles

    The cargo securement rules add specific requirements for particular commodities, including logs, dressed lumber, metal coils, paper rolls, concrete pipe, intermodal containers, vehicles, crushed cars, roll on containers and large boulders.

  32. 32. Using the snub braking method on a downgrade, when does the driver release the brakes?

    Show answer

    Answer A: After speed has dropped about 5 mph below the safe speed

    The driver brakes firmly to about 5 mph under the chosen safe speed, releases to let the brakes cool, then repeats when the safe speed returns.

  33. 33. 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.

  34. 34. What does the gross combination weight rating cover?

    Show answer

    Answer B: The maximum loaded weight of the power unit together with the trailer or trailers it tows

    The combination rating takes in the power unit and everything behind it, loaded, as specified by the manufacturer.

  35. 35. 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.

  36. 36. Which vehicles are most likely to get hung up on a raised railroad crossing?

    Show answer

    Answer A: Low-slung units such as car carriers and lowboys

    Vehicles with low ground clearance or a long wheelbase can bottom out on a humped crossing and become stuck on the tracks.

  37. 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. 38. Which road users are hardest to see at night?

    Show answer

    Answer C: Pedestrians and cyclists in dark clothing

    People on foot or on a bicycle carry no lights of their own in many cases, so they appear only when the headlights reach them.

  39. 39. With water standing on the road, hydroplaning can begin at speeds as low as what?

    Show answer

    Answer D: 30 mph

    When enough water covers the surface, the tires can ride up on it and lose contact at speeds as low as 30 mph.

  40. 40. You are not certain that your loaded vehicle will clear a low overpass. What should you do?

    Show answer

    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.

  41. 41. Your truck has a backup alarm that sounds whenever reverse is selected. What may a driver rely on it for?

    Show answer

    Answer D: Very little; it warns some people but cannot show you what is behind the vehicle

    An alarm may not be heard over yard noise or by someone wearing hearing protection, so it never replaces looking at the path yourself.

  42. 42. 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.

  43. 43. Part of looking well ahead is planning an out. What does that mean?

    Show answer

    Answer B: Keeping an escape path in mind in case traffic stops suddenly

    Because a heavy vehicle often cannot stop in time, good drivers continuously note where they could steer if the space ahead closes.

  44. 44. Why does a cracked frame rail or cross member make a vehicle unsafe?

    Show answer

    Answer B: The frame carries the whole load, and a crack can spread until the structure fails

    The frame is the backbone that supports the body, the load and the running gear, so a crack in it is a structural failure that grows with every mile.

  45. 45. Which set of emergency equipment must be carried on a commercial motor vehicle?

    Show answer

    Answer D: A fire extinguisher, spare electrical fuses unless the vehicle has circuit breakers, and warning devices

    The required kit is a properly charged and rated fire extinguisher, spare fuses when the vehicle uses them, and warning devices for a stopped vehicle.

  46. 46. At the end of the day you find no defects on a property carrying vehicle. What does the federal rule require?

    Show answer

    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.

  47. 47. 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.

  48. 48. 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.

  49. 49. During a trip you stop for a break. Which items should you check before driving on?

    Show answer

    Answer B: Tires, wheels and rims, brakes, lights, reflectors, electrical connections and cargo securement

    Critical items can change during a trip, so each stop is used to recheck the tires, wheels, brakes, lights, connections and cargo.

  50. 50. Your vehicle stalls on a railroad crossing and a train is coming. What should you do?

    Show answer

    Answer C: Get out at once and move toward the train, well off to one side

    Leave the vehicle immediately and move at an angle toward the oncoming train, so that wreckage thrown forward by the impact travels away from you.