Wyoming WYDOT CDL General Knowledge Practice Test 5
Test 5 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. 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.
-
2. 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.
-
3. 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.
-
4. What is the minimum tread depth required in every major groove of a steering axle tire?
Show answer
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.
-
5. After starting the engine, how quickly should the oil pressure gauge come up to its normal range?
Show answer
Answer B: Within a few seconds
Oil pressure should build within seconds of starting; if it stays low, the engine is not being lubricated and should be shut down.
-
6. What is the correct way to make a normal stop?
Show answer
Answer A: Push the brake pedal down gradually and bring the vehicle to a smooth stop
Steady, progressive pedal pressure keeps the vehicle stable and lets the driver behind you react to a predictable slowdown.
-
7. You can see a crack in a brake drum that runs across more than half the width of the friction surface. What does this mean?
Show answer
Answer C: The drum is defective and must be repaired before the vehicle is driven
Cracks longer than half the width of the friction area mean the drum can break apart under braking heat and must be replaced.
-
8. What is the correct way to test the parking brake before a trip?
Show answer
Answer C: With the parking brake set, put the vehicle in a low gear and gently try to move forward
A parking brake that holds against a gentle pull in low gear is working; if the vehicle moves, the brake needs adjustment or repair.
-
9. When should a lower gear be selected for a long downgrade?
Show answer
Answer D: Before you start down the hill
The gear is chosen at the top, while speed is still low, because a heavy vehicle already rolling fast may not go into a lower gear at all.
-
10. An unblocked article is 8 feet long and weighs 900 pounds. How many tiedowns does the federal rule require?
Show answer
Answer B: Two
Only an article that is 5 feet or shorter and 1,100 pounds or lighter can be held with a single tiedown; anything longer than 5 feet needs at least two whatever it weighs.
-
11. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?
Show answer
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.
-
12. How long must a motor carrier keep a driver vehicle inspection report and the certification of repairs?
Show answer
Answer B: Three months
The original report and the certifications attached to it are kept on file for three months from the date the report was prepared.
-
13. On the Interstate System, what is the federal maximum weight allowed on a single axle?
Show answer
Answer A: 20,000 pounds
Federal limits for the Interstate System cap one single axle at 20,000 pounds.
-
14. What should the ammeter or voltmeter show once the engine is running?
Show answer
Answer D: A reading in the normal charging range
With the engine running, the alternator should be charging; a discharge reading or an abnormal charge level means an electrical fault.
-
15. A car ahead of you keeps drifting within its lane and moving unevenly. What should you assume?
Show answer
Answer C: The driver may be distracted, lost or impaired
Unsteady lane keeping is a classic clue to a driver who is not in full control, so the safe response is to keep back and give plenty of room.
-
16. Part of your load stands high enough to hide a rear lamp or a reflector. What must be done?
Show answer
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.
-
17. How do you get more engine braking from an automatic transmission on a downgrade?
Show answer
Answer B: Select a lower range before starting down
Locking the transmission into a lower range keeps engine speed high enough to hold the vehicle back and spares the service brakes.
-
18. You stop to check the load. Which set of things are you looking at?
Show answer
Answer C: Tight tiedowns, cargo that has not moved, secure doors and tarps still fastened
A cargo check covers the load and everything holding it: whether it has shifted, whether the devices are still tight, and whether doors and covers are still closed and fastened.
-
19. 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.
-
20. 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.
-
21. You are making a right turn and cannot complete it without swinging into the oncoming lane. An oncoming car is approaching. What should you do?
Show answer
Answer A: Wait and let the oncoming vehicle pass before completing the turn, and do not back up
The oncoming vehicle has the lane; backing up in traffic is dangerous, so hold your position and finish the turn once the way is clear.
-
22. Which situations call for a mirror check in a commercial vehicle?
Show answer
Answer A: Every lane change, turn, merge and tight maneuver
Mirrors must be checked regularly and always before, during and after any movement that changes the path of the vehicle.
-
23. When speed doubles, what happens to braking distance?
Show answer
Answer D: It becomes roughly four times as long
Braking distance rises with the square of speed, so twice the speed needs about four times the distance to stop.
-
24. 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.
-
25. Within total stopping distance, what exactly is perception distance?
Show answer
Answer D: The distance traveled from the moment your eyes see a hazard until your brain identifies it
Perception distance covers only the time between seeing a hazard and recognizing it as a hazard, before any physical reaction begins.
-
26. Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?
Show answer
Answer B: Gravity adds to the momentum and the brakes heat up faster
The heavier the vehicle, the more energy the brakes must turn into heat, and heat is exactly what makes brakes fade on a long descent.
-
27. Besides staying secure, cargo carried inside a vehicle must not do what?
Show answer
Answer C: Block the driver view or access to emergency equipment and exits
Cargo may not obstruct the view to the front or sides or prevent the driver from reaching emergency equipment and exits.
-
28. 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.
-
29. A commercial vehicle stops on the shoulder of a one-way or divided highway. Where do the three warning devices go?
Show answer
Answer A: At 10 feet, 100 feet, and 200 feet back toward approaching traffic
Traffic arrives from one direction only, so all three devices are set back toward it at 10, 100, and 200 feet, and they must be out within ten minutes.
-
30. 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.
-
31. 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.
-
32. You must drive well below the speed of surrounding traffic, for example when climbing a steep grade with a heavy load. What should you do?
Show answer
Answer B: Turn on the four-way flashers to warn following traffic, where state law allows it
Flashers warn faster traffic that a slow-moving vehicle is ahead, which helps prevent rear-end crashes; some states restrict their use while moving, so check the local rule.
-
33. What is the main purpose of a retarder fitted to a heavy vehicle?
Show answer
Answer B: To help slow the vehicle and reduce the need to use the service brakes
Exhaust, engine, hydraulic and electric retarders all slow the vehicle so the brakes stay cool and wear less, especially on grades.
-
34. During a right turn in a tractor-trailer, what are you looking for in the right hand mirror?
Show answer
Answer B: Whether the trailer will clear the curb and whether anything has moved alongside you
The right mirror is what tells you how close the trailer wheels are running to the curb and whether a vehicle or a cyclist has slipped into the space on your right.
-
35. 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.
-
36. You have finished a lane change in a vehicle whose turn signal does not cancel by itself. What must you do?
Show answer
Answer D: Turn the signal off yourself
A signal left running tells other drivers you are about to move again, and they may act on that false information.
-
37. The temperature is around freezing and the road looks wet. What is a practical way to tell whether it is icy?
Show answer
Answer C: Check for ice building up on the mirrors, antenna or the front of the vehicle
Ice that forms on the mirror, antenna or windshield is a warning that the road surface is freezing too, and black ice can look like a wet road.
-
38. How does a load carried high in the trailer affect safe speed through a curve?
Show answer
Answer B: It raises the rollover risk, so the speed must be lower
A high center of gravity lets the vehicle tip long before the tires lose their grip, so height of the load directly limits curve speed.
-
39. Which of these is a suspension defect you must look for during the walkaround?
Show answer
Answer D: Cracked or broken spring leaves, loose or broken U-bolts, or leaking air suspension bags
Broken springs, failed U-bolts and leaking air bags let the axle shift or the body drop, which can make the vehicle impossible to control.
-
40. When is tire pressure most accurately compared with the recommended figure?
Show answer
Answer B: When the tires are cold, before the vehicle has been driven
Recommended pressures are cold pressures, so a reading taken before the tires have heated up is the only one that can be compared directly.
-
41. The engine oil pressure gauge falls toward zero while you are driving. What should you do?
Show answer
Answer C: Stop as soon as it is safe to do so and shut the engine down
Loss of oil pressure destroys an engine in a very short time, so the correct response is to stop and shut down rather than to drive on.
-
42. 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.
-
43. 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.
-
44. After coupling, where should the fifth wheel release handle be?
Show answer
Answer A: In the locked position with the safety latch in place
The handle must be pushed in and latched, because a handle left out means the jaws can open and release the trailer while you are driving.
-
45. 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.
-
46. 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.
-
47. Which of these is a major cause of skids in heavy vehicles?
Show answer
Answer C: Over-braking, over-steering, over-acceleration or driving too fast for conditions
Skids happen when the tires are asked for more grip than the road can give, which happens through braking, steering or accelerating too hard or simply too much speed.
-
48. Regular mirror checks during a long trip can reveal which developing problem?
Show answer
Answer D: Smoke coming from a tire or from a wheel
Overheating tires, wheel bearings and brakes usually show as smoke long before anything appears on the dash, and mirrors are where a driver sees it.
-
49. A fire has started in the vehicle. How should the extinguisher be used?
Show answer
Answer B: Stay as far back as the reach of the extinguisher allows, stand upwind, and aim at the base of the fire
Aiming at the base attacks what is actually burning, and staying upwind and well back protects the driver from heat, smoke and the flames themselves.
-
50. Where is the yellow antilock brake malfunction lamp on a trailer, and what does it mean if it stays lit?
Show answer
Answer D: On the left side, at the front or rear corner, and it means the antilock function may not be working
Trailers carry the yellow lamp on the left side, and a lamp that stays on after the bulb check means the antilock function may be lost even though the normal brakes still work.