Wyoming WYDOT CDL General Knowledge Practice Test 6
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. 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.
-
2. 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.
-
3. A vehicle carries placards on its front, rear and both sides. What is the main purpose of those placards?
Show answer
Answer C: To tell emergency responders and other people what hazard the cargo presents
Placards warn everyone around the vehicle, especially emergency responders, about the kind of hazard the cargo presents.
-
4. 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.
-
5. Why should high beams not be used in fog?
Show answer
Answer A: The light reflects back off the droplets and blinds you
Fog is made of water droplets that scatter light straight back at the driver, so a stronger beam makes the wall of glare worse rather than better.
-
6. 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.
-
7. 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.
-
8. A dispatcher tells you to take a trailer you believe is loaded badly enough to be unsafe. What should you do?
Show answer
Answer C: Refuse to move it until the load has been made safe
The driver may not operate a vehicle whose cargo is not properly distributed and secured, and an instruction from an employer does not change that.
-
9. 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.
-
10. During the walkaround inspection, where does the driver normally start and how does the check proceed?
Show answer
Answer C: At the left front of the vehicle, working around it in a set order that returns to the cab
The walkaround follows the same route every time, starting at the left front and circling the vehicle, so that nothing is skipped when the driver is tired or rushed.
-
11. How long is a Wyoming commercial learner permit valid, and how long must it be held before the skills test?
Show answer
Answer D: Valid 365 days and held at least 14 days before skills testing
A Wyoming commercial learner permit is valid for 365 days and must be held for at least 14 days before the applicant may take the skills test.
-
12. How does bracing differ from blocking when securing cargo?
Show answer
Answer B: Bracing runs from the upper part of the cargo to the floor or walls to keep it from moving, while blocking fits snugly against the cargo
Blocking is shaped to fit against the front, back or sides of a piece of cargo; bracing supports it from above so it cannot tip or shift.
-
13. 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.
-
14. An automatic transmission is left in its normal drive position as the vehicle rolls down a long grade. What does it tend to do?
Show answer
Answer A: Shift up as road speed rises, so engine braking falls away
An automatic left in drive keeps upshifting as speed builds, which is the opposite of what you want on a grade; that is why the driver must select a low range.
-
15. Which items belong to the in-cab part of the inspection?
Show answer
Answer D: Gauges, controls, mirrors, windshield, wipers, horn, heater and defroster
The in-cab step checks the instruments and controls the driver depends on, along with mirrors, glass, wipers, horn and the heater and defroster.
-
16. What makes a brake hose or air line a defect during the walkaround?
Show answer
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.
-
17. Which step of the seven-step inspection method comes immediately after checking the engine compartment?
Show answer
Answer D: Start the engine and inspect the inside of the cab
Once the hood is closed the driver moves to the driver seat, starts the engine and checks gauges, controls and warning devices before going any further.
-
18. 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.
-
19. A chain rated at 6,600 pounds is fitted with a hook rated at 4,700 pounds. What is the working load limit of that assembly?
Show answer
Answer A: 4,700 pounds, the rating of the weakest part
An assembly is only as strong as its weakest component, so hooks, binders and links all count and the lowest rating governs.
-
20. What should you check about the tire valve stems during the walkaround?
Show answer
Answer D: That the stems are not cut, cracked or leaking and the caps are in place
A split stem or a missing cap lets air escape or lets dirt into the valve, and either one can flatten a tire between stops.
-
21. 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.
-
22. 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.
-
23. Why should the mirrors be checked repeatedly while you make a tight turn?
Show answer
Answer C: To watch the rear of the vehicle clear other vehicles and objects
In a long vehicle the rear wheels cut inside the path of the front wheels, so only the mirrors show whether the rear is clearing curbs, poles and other vehicles.
-
24. During uncoupling, when may the fifth wheel locking lever be released?
Show answer
Answer D: Only after the landing gear is down and taking the weight of the trailer
The landing gear has to be supporting the trailer before the lock is released; otherwise the trailer nose can drop as soon as the tractor pulls out.
-
25. 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.
-
26. A straight truck has a long body behind the rear axle. What happens to that overhang in a sharp left turn?
Show answer
Answer D: It swings out to the right and can strike a vehicle or an object on that side
Body that hangs behind the rear axle swings the opposite way to the turn, so the tail of the truck sweeps out into the next lane or over the curb.
-
27. What is the best practice when fog is thick enough to hide the road ahead?
Show answer
Answer B: Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves
The safest choice in heavy fog is not to be driving in it, and if you are already in it your speed has to come down before your visibility does.
-
28. An intermodal container is being carried on an ordinary flatbed rather than on a container chassis. What does that mean for securement?
Show answer
Answer B: It must be secured with tiedowns that meet the container securement requirements
A container carried on a vehicle that is not fitted with integral locking devices has to be secured to the deck with tiedowns that satisfy the rules for containers.
-
29. What is checked about the engine cooling system during the engine compartment inspection?
Show answer
Answer C: That the coolant level is adequate and the radiator and hoses are not leaking
A low coolant level or a leaking hose leads to overheating, which can stop the vehicle in a place where stopping is dangerous.
-
30. 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.
-
31. A 40 foot straight truck and a 70 foot tractor-trailer make the same right turn. Which needs more room and why?
Show answer
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.
-
32. 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.
-
33. Before starting a trip, what must the driver confirm about the weight of the loaded vehicle?
Show answer
Answer A: That it is within the legal gross and axle limits for the route being driven
Overweight vehicles brake poorly, damage tires and suspension components, and can be put out of service at a scale, so weight is checked before the wheels turn.
-
34. The brake pedal goes to the floor in a vehicle with hydraulic brakes. What can you do to build some braking pressure?
Show answer
Answer B: Pump the brake pedal rapidly, which may bring back enough pressure to slow the vehicle
Pumping can restore some hydraulic pressure; along with downshifting and the parking brake it is one of the ways to stop when the pedal fails.
-
35. At 55 mph on dry pavement with good brakes, total stopping distance for a loaded heavy vehicle is roughly what?
Show answer
Answer B: About 400 feet or more
Perception, reaction, and braking together add up to roughly 400 feet or more, farther than the length of a football field.
-
36. What does the driver check in the final step of the seven-step inspection?
Show answer
Answer A: Hydraulic brake leaks where those brakes are fitted, then the parking brake and the service brakes
The last step is done with the engine started: test for hydraulic leaks on vehicles with hydraulic brakes, then prove that the parking brake holds and that the service brakes stop the vehicle.
-
37. On the Interstate System, what are the federal maximums for a tandem axle group and for gross vehicle weight?
Show answer
Answer B: 34,000 pounds and 80,000 pounds
The federal Interstate limits allow 34,000 pounds on a tandem axle group and 80,000 pounds gross.
-
38. Which wheel or rim condition must be treated as a defect during the walkaround?
Show answer
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.
-
39. Apart from the legal duty, what is the main practical reason for a thorough pre-trip inspection?
Show answer
Answer A: It finds problems that could cause a breakdown or a crash before the vehicle is on the road
A defect found in the yard is an inconvenience, while the same defect found at highway speed can be a crash, so the inspection is where problems are cheapest to fix.
-
40. 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.
-
41. What does a front-end header board on a van or flatbed protect against?
Show answer
Answer A: Cargo moving forward toward the cab in a crash or hard stop
The header board, often called a headache rack, blocks forward movement of the load toward the driver.
-
42. When must a post-trip inspection be made?
Show answer
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.
-
43. What do the U-bolts on a leaf spring suspension do?
Show answer
Answer A: They clamp the spring assembly to the axle so it cannot move
U-bolts hold the spring pack tight against the axle, and a loose or broken U-bolt lets the axle slide out of place under load.
-
44. You are pulling a loaded pneumatic dry bulk trailer and approach an exit ramp posted at 35 mph. What is the safest approach?
Show answer
Answer C: Slow to well below the posted speed before the ramp begins
A dry bulk trailer carries its weight high and the load can move, so the ramp speed posted for a car is far too fast and the slowing must be finished before the curve.
-
45. You are backing a tractor-trailer in a straight line and the trailer starts to drift to the left. What is the standard correction?
Show answer
Answer D: Turn the top of the steering wheel a little to the left, toward the drift
Small corrections made in the direction the trailer is drifting bring it back into line; large or opposite movements make the drift worse.
-
46. 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.
-
47. You pick up a sealed trailer at a shipper. What should you check before leaving the dock?
Show answer
Answer B: That the seal number matches the paperwork and that the doors are properly closed
You cannot look at a sealed load, but you can confirm that the seal is intact, that its number matches the documents and that the doors are secure.
-
48. Why must tiedowns be rechecked during a trip even when they were tight at the start?
Show answer
Answer C: Road vibration and cargo movement can loosen them as the miles go by
Straps and chains settle and loosen as the vehicle bounces and the cargo shifts slightly, so the load must be rechecked at the required intervals.
-
49. Your brakes are starting to fade on a mountain downgrade and a sign shows an escape ramp one mile ahead. What should you do?
Show answer
Answer B: Plan to use the ramp instead of trying to reach the bottom
Fading brakes on a grade only get worse, and the ramp exists precisely so a driver does not have to gamble on the rest of the descent.
-
50. 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.