Alaska 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 Alaska test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. How long must an Alaska applicant hold a commercial learner permit before taking the road skills test?
Show answer
Answer B: At least 14 days
Alaska requires a commercial learner permit to be held for at least 14 days before the road skills test, including when upgrading to a higher class or adding an endorsement that needs a skills test.
-
2. 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.
-
3. 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.
-
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. What should you check about the fuel tank during the walkaround?
Show answer
Answer A: That it is securely mounted, the cap is on tight and there are no leaks
A loose tank or a missing cap can spill fuel, and any fuel leak is a fire hazard that makes the vehicle unsafe to drive.
-
6. 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.
-
7. A strap is a little too long, so a driver ties a knot in it to take up the slack. Is that acceptable?
Show answer
Answer C: No, tiedowns must not contain knots
A knot destroys the rated strength of a tiedown, so the rules do not allow knotted securement devices; the excess is taken up by the winch or ratchet instead.
-
8. What financial responsibility must a person carrying passengers or freight for hire in Alaska maintain?
Show answer
Answer A: 500,000 dollars for bodily injury and 200,000 for property damage
Alaska law requires a carrier of passengers or freight for hire to maintain 500,000 dollars for bodily injury or death and 200,000 dollars for property damage in a single occurrence.
-
9. You are hauling a load of steel plate that is well within every weight limit but is stacked five feet high on a flatbed. What is the main concern?
Show answer
Answer A: The center of gravity is high, so the rig will roll more easily in a curve
Legal weight does not make a load safe; height raises the center of gravity and it is height, not weight alone, that decides how readily the vehicle rolls over.
-
10. 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.
-
11. What are the rules for using your turn signal before a turn or lane change?
Show answer
Answer A: Signal early, keep the signal on until the turn is finished, then cancel it
An early, continuous signal tells others what you plan to do; cancelling afterward keeps the signal from misleading them.
-
12. You need to pull off onto the shoulder because of a problem with the load. How should you communicate that to other drivers?
Show answer
Answer D: Signal the move, then switch on the four-way flashers once stopped
Other drivers need a signal before you leave the lane and a clear warning once the vehicle is stopped near the traffic lanes.
-
13. 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.
-
14. An article of cargo has been blocked so that it cannot move forward. How many tiedowns does the federal rule call for?
Show answer
Answer A: One tiedown for every 10 feet of article length, or any part of that
Blocking against forward movement lowers the requirement to one tiedown per 10 feet of length or fraction of 10 feet.
-
15. 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.
-
16. Why does a heavy vehicle need a much larger gap than a car in order to cross or enter traffic?
Show answer
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.
-
17. You are pulling away from the curb after a delivery. Why is a mirror check needed first?
Show answer
Answer B: A cyclist or a vehicle may be coming up alongside you
Traffic and cyclists can arrive alongside a parked vehicle at any moment, so the mirrors must be checked immediately before pulling out.
-
18. Why should a long vehicle never swing out to the left before starting a right turn?
Show answer
Answer D: Another driver may read it as a left turn or pass on your right
Swinging left opens a gap on your right that a car will move into, and it also sends a false message about which way you are going.
-
19. 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.
-
20. 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.
-
21. 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.
-
22. Which factors determine a safe speed for a long, steep downgrade?
Show answer
Answer C: The steepness and length of the grade, the weight of the vehicle and cargo, and the road and weather conditions
Gravity, weight and traction all decide how fast a heavy vehicle can safely descend, which is why signs often post lower speeds for trucks on grades.
-
23. Where do you find the maximum weight a tire can safely carry?
Show answer
Answer D: Stamped on the sidewall of the tire itself
Each tire is marked with the greatest weight it can carry at a stated inflation pressure, and the load on an axle must stay within the total for its tires.
-
24. 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.
-
25. How can a driver tell that a shipment includes hazardous materials?
Show answer
Answer B: The shipping paper describes them and the packages carry hazard warning labels
Hazardous materials are identified on the shipping paper with their shipping name and hazard class, and the packages themselves carry labels showing the hazard.
-
26. 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.
-
27. 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.
-
28. What is the danger of letting engine speed climb past the top of the rated rpm range before you shift?
Show answer
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.
-
29. How does a driver keep a vehicle with a manual transmission from rolling back when starting on an upgrade?
Show answer
Answer D: Partly engage the clutch before the right foot leaves the brake, or hold the vehicle with the parking brake until the engine pulls
Something has to hold the vehicle during the instant the foot moves from the brake to the accelerator, and that is either the clutch at its engagement point or the parking brake.
-
30. 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.
-
31. 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.
-
32. 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.
-
33. 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.
-
34. 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.
-
35. You are inspecting the vehicle alone and need to confirm that the stop lights work. Which method is correct?
Show answer
Answer A: Have a helper press the brake pedal, or apply the brake in a way that keeps it on while you check from outside
Stop lights are checked from outside the vehicle while the brakes are applied, so a helper or a brake held on is needed.
-
36. The engine has overheated and you need to check the coolant. What is the safe procedure with a pressurized radiator cap?
Show answer
Answer A: Shut the engine off, let the system cool, protect your hands, turn the cap slowly to its first stop so pressure escapes, step back, then remove it
A hot pressurized system throws steam and boiling coolant out of the opening, so the pressure is released slowly and only after the engine has cooled.
-
37. 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.
-
38. What does the federal bridge formula do?
Show answer
Answer C: It reduces the weight allowed on a group of axles as those axles get closer together
Axles bunched together concentrate the load on a short span of a bridge, so the formula lowers the allowable weight as the spacing shrinks.
-
39. Two vehicles of exactly the same length make a right turn, one gently and one very tightly. What is the effect on off-tracking?
Show answer
Answer A: Turning more sharply increases off-tracking, so the tight turn needs more room
Off-tracking depends on both the length of the vehicle and the sharpness of the turn; a tighter corner brings the rear wheels further inside the path of the front wheels.
-
40. What does it mean to overdrive your headlights at night?
Show answer
Answer D: Driving so fast that you cannot stop within the distance lit by your headlights
You must be able to stop inside the distance you can see; at night that distance is limited by the headlights, so speed must be lowered to match.
-
41. A vehicle becomes unsafe while you are already on the road. What does the federal rule allow?
Show answer
Answer A: Continuing only to the nearest place where repairs can safely be made
If stopping where you are would be more dangerous than moving, the rule allows you to reach the nearest place where the vehicle can safely be repaired, and no further.
-
42. 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.
-
43. You are about to slow down sharply on a highway to make a turn into a narrow driveway. How can you warn the drivers behind you?
Show answer
Answer C: Tap the brake pedal a few times so the brake lights flash before you slow down
A few light taps flash the brake lights and give following drivers an early warning that you are about to slow or stop.
-
44. 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.
-
45. What minimum sentence does Alaska impose for a first conviction of driving a commercial vehicle while disqualified?
Show answer
Answer B: 20 days with 10 suspended, plus 80 hours of community work service
Alaska requires a minimum sentence of not less than 20 days imprisonment with 10 days suspended and at least 80 hours of community work service for a first conviction, plus a further revocation of at least 90 days.
-
46. During the walkaround you notice one tire on an axle is a radial and the tire next to it is bias-ply. What should you do?
Show answer
Answer B: Treat it as a defect, because radial and bias-ply tires must not be mixed on the same axle
Radial and bias-ply tires flex and grip differently, so mixing them on one axle makes the vehicle handle unpredictably and is not allowed.
-
47. Which of these is NOT on the federal list of parts and accessories the driver must be satisfied are in good working order before driving?
Show answer
Answer D: The seat cushion upholstery
The federal pre-trip rule names brakes, steering, lights and reflectors, tires, horn, wipers, mirrors, coupling devices, wheels and rims, and emergency equipment; seat upholstery is not on that list.
-
48. On a multilane highway, which lane should a heavy vehicle normally use?
Show answer
Answer A: The right lane, except to pass or where signs direct otherwise
Keeping right leaves the faster lanes free and reduces the number of vehicles that have to move around a slower, heavier vehicle.
-
49. How do you confirm that the coupling is locked before pulling out of the yard?
Show answer
Answer D: By locking the trailer brakes and pulling gently forward against them
The tug test loads the coupling in the direction that would pull it apart, so if the jaws are not closed on the kingpin you find out at walking pace.
-
50. 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.