Wyoming WYDOT CDL General Knowledge Practice Test 3
Test 3 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 Wyoming test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. How soon must a commercial driver license holder who moves to Wyoming obtain a Wyoming CDL?
Show answer
Answer A: Within 30 days of becoming a Wyoming resident
CDL holders must transfer their commercial driver license to their new state of domicile within 30 days, so the one-year allowance Wyoming gives other new residents does not apply to them.
-
2. You drive a 40 foot straight truck at 50 miles per hour in good conditions. What following distance does the rule of thumb call for?
Show answer
Answer A: 5 seconds
One second for every 10 feet of vehicle length gives 4 seconds, and one extra second is added for speeds above 40 miles per hour.
-
3. The coolant temperature gauge climbs above its normal range on a long grade. What is the correct response?
Show answer
Answer C: Stop when it is safe to do so and find the cause before going on
Rising coolant temperature signals a fault such as a lost belt, a leak or a blocked radiator, and continuing can turn a repair into a destroyed engine.
-
4. 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.
-
5. When should the horn of a commercial vehicle be used?
Show answer
Answer C: Only when it is needed to avoid a crash
An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.
-
6. 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.
-
7. Federal rules keep recapped and retreaded tires off the front wheels of which vehicle?
Show answer
Answer B: Any bus carrying passengers
The federal rule names buses: a bus may not run with regrooved, recapped or retreaded tires on its front wheels, because a steer tire failure with passengers aboard takes away steering control.
-
8. What is required of the hooks, rails, rings and anchor points that tiedowns attach to?
Show answer
Answer A: They must be part of the vehicle and strong enough for the load being secured
A tiedown is only as strong as what it is hooked to, so anchor points must be proper vehicle fittings rated for the job.
-
9. When traction is poor, such as on packed snow, how should you speed up?
Show answer
Answer C: Very gradually, so the drive wheels do not spin
Gentle throttle keeps the drive wheels from breaking traction, because spinning wheels give up both grip and directional control.
-
10. 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.
-
11. As a long vehicle goes around a corner, how do the rear wheels travel compared with the front wheels?
Show answer
Answer A: They follow a tighter path, closer to the inside of the turn
The rear wheels off-track toward the inside of the turn, and the longer the vehicle the bigger the difference, which is why the front must swing wide enough to keep the rear off the curb.
-
12. What is the basic rule about backing a large vehicle?
Show answer
Answer B: Avoid backing whenever there is another way
Backing is dangerous because you cannot see everything behind you, so the manual tells drivers to plan routes and parking that avoid it.
-
13. 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.
-
14. While checking the in-cab gauges after start-up, what should the coolant temperature gauge do?
Show answer
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.
-
15. Which exhaust system condition must be reported as a defect?
Show answer
Answer B: A section repaired by wrapping tape or patching material around the pipe
Exhaust parts may not be patched with wrap or tape, because the repair does not contain the gas or the heat and it fails quickly in service.
-
16. Why must exhaust components be checked for contact with other parts of the vehicle?
Show answer
Answer B: Hot exhaust parts touching fuel lines, tires or wiring can start a fire
Exhaust pipes run hot enough to ignite fuel and melt insulation, so they must be kept clear of the fuel system, the tires and the electrical harness.
-
17. Under the federal air brake standard, the low air pressure warning must come on before reservoir pressure drops below what level?
Show answer
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.
-
18. 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.
-
19. 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.
-
20. 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.
-
21. 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.
-
22. What must the driver confirm about the required emergency equipment before a trip?
Show answer
Answer A: That it is in place, in working order and ready to be used
Federal rules require the driver to be satisfied that the emergency equipment is present and ready, because it is needed at the worst possible moment.
-
23. 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.
-
24. You have countersteered to correct a rear-wheel skid and the vehicle straightens out. What must you be ready for next?
Show answer
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.
-
25. 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.
-
26. What tells a driver when to shift up in a vehicle with a manual transmission?
Show answer
Answer C: Engine speed in rpm together with road speed
Shift points are judged from engine rpm and road speed, using the operating range the manufacturer specifies for that engine.
-
27. What must be checked about the cargo doors and any tarpaulin before a trip?
Show answer
Answer B: That the doors are closed and latched and that any tarp is tied down securely
An unlatched door or a loose tarp can swing open or tear free at speed, spilling cargo or blocking the view of the traffic behind you.
-
28. Why should water never be used on an electrical fire or a gasoline fire?
Show answer
Answer C: It spreads the fuel and conducts the current
Water carries current back to the person holding the hose and floats burning fuel outward, which is why a B:C rated extinguisher is carried instead.
-
29. 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.
-
30. Within what distance should high beams be lowered at night?
Show answer
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.
-
31. 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.
-
32. 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.
-
33. 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.
-
34. 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.
-
35. Why is a leaking exhaust system on a commercial vehicle dangerous to the driver?
Show answer
Answer B: It can let carbon monoxide reach the cab, where it can poison the occupants
Exhaust gas contains carbon monoxide, which has no smell and dulls the driver judgment long before it becomes obvious that anything is wrong.
-
36. Why should the radiator cap never be removed while the engine is hot?
Show answer
Answer A: The cooling system is under pressure and scalding coolant can be sprayed out
A hot cooling system holds pressurized coolant above its normal boiling point, so releasing the cap can throw boiling liquid and steam at whoever is holding it.
-
37. You are hauling an open box of loose gravel. What does that load require?
Show answer
Answer A: A cover, so that material cannot blow off or spill onto the road
Loose material that can be blown or spilled has to be covered so it does not come out of the body and strike traffic behind.
-
38. Under Wyoming's chain law, how must a commercial vehicle's tire chains be arranged when chains are required?
Show answer
Answer B: On at least two drive wheels at opposite ends of the same drive axle
Wyoming statute requires a commercial vehicle operator to affix tire chains to at least two drive wheels at opposite ends of the same drive axle when chains are required under the chain law.
-
39. Does the federal texting ban apply to a company dispatching device mounted in the cab?
Show answer
Answer B: Yes, entering or reading text on it while driving is banned
The rule is written around the act of reading or entering text on any electronic device, not around who owns the device.
-
40. 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.
-
41. What is checked about the clutch and the gearshift during the in-cab inspection?
Show answer
Answer D: That the clutch free play is within the range the manufacturer specifies
Too little or too much clutch free play causes slipping or dragging, either of which can leave the driver unable to select the gear a hill demands.
-
42. What is the first step of the standard seven-step vehicle inspection?
Show answer
Answer C: A general overview of the vehicle, including the last inspection report
The routine opens with a walk-up overview of the vehicle and a review of the previous inspection report so known defects are addressed first.
-
43. 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.
-
44. Why do worn tires lose grip so quickly on a wet road?
Show answer
Answer D: Shallow tread cannot move water out from under the tire
The grooves in a tire exist to channel water away so the rubber can touch the road, and a worn tire has lost that capacity.
-
45. How are Wyoming CDL written tests structured and scored?
Show answer
Answer A: All written tests are multiple choice and require 80 percent to pass, and only the failed test has to be retaken
WYDOT states that all CDL written tests are multiple choice, that the passing score is 80 percent, and that an applicant who fails only has to retake the test that was failed.
-
46. A strap runs from an anchor point on one side of the trailer, over the load, and down to an anchor point on the opposite side. How much of its working load limit counts toward the total required?
Show answer
Answer C: All of it
A tiedown that is anchored on one side, passes over or around the cargo and is anchored on the other side counts its full working load limit toward the aggregate figure.
-
47. 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.
-
48. 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.
-
49. 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.
-
50. On packed snow, how much should a commercial driver reduce speed?
Show answer
Answer D: By about one half or more
Packed snow costs far more traction than rain, so speed should be cut by half or more.