CDL Permit Practice Test (50 Questions Answers)

CDL Permit Practice Test (50 Questions Answers): In order to get this special license, you must first take and pass the required CDL knowledge test and skills tests. Using this free sample test correctly will prepare you to take and pass these tests. This practice test is consist of 50 questions and is followed by an answer key.

Taking our free CDL Permit Practice Test and any other practice Endorsement Tests that apply to your vehicle type, and studying the explanations of the correct answers for the practice tests, you can find out how well you are prepared for the actual Commercial Driver’s License Exam and what material you need to review again.

CDL Permit Practice Test (50 Questions Answers)

Test Name	CDL Practice Test 2025
Language	English
License	CDL (Class A, B, or C),
Total Questions	50 Knowledge Practice Test
Test For	Commercial Driver License
Test Preparation	Driving Knowledge
Country	USA
Explanation	No

0 votes, 0 avg

CDL General Knowledge Test 6

1 / 50

What is the total stopping distance when driving a heavy vehicle on dry pavement at 55 mph?

A) 6 seconds

B) 5 seconds

C) 7 1/2seconds

D) 4 1/2 seconds

2 / 50

You are driving a 60-foot rig at 55 mph. How many seconds of space should you have between you and the vehicle ahead?

A) 6 seconds

B) 7 seconds

C) 5 seconds

D) 8 seconds

3 / 50

To extinguish an electrical fire,

A) use the A:B:C extinguisher on the flames of the fire.

B) use a lot of water.

C) use the B:C extinguisher on the base of the fire.

D) pull into a service station and wait for qualified firefighters.

4 / 50

Which of the following is a sign of a tire failure?

A) All of the above

B) Vibration

C) The steering wheel pulls to one side

D) A loud “bang”

5 / 50

Where and when is it best to downshift?

A) After starting down a hill

B) Before entering a curve

C) Before speeding up

D) After starting up a hill

6 / 50

A tie rod is part of the ________ system.

A) steering

B) brake

C) suspension

D) exhaust

7 / 50

You are approaching a vehicle for a pre-trip inspection. What should be the first step?

A) Fastening your seatbelt

B) Putting the vehicle key in your pocket

C) Writing a written report on the condition of the vehicle

D) Starting the engine

8 / 50

Which of the following is one of the potential causes of fire in the electrical system?

A) Flammable cargo

B) Short circuits due to damaged insulation

C) Duals that touch

D) Poor ventilation

9 / 50

What is a tractor jackknife?

A) A drive-wheel skid

B) A device used in the hydraulic system

C) Another name for hard steering

D) A type of trailer truck

10 / 50

How much tread depth should you have on your front tires when driving in the winter?

A) Minimum of 4/32 inch

B) Under 4/32 inch

C) Minimum of 2/32 inch

D) Maximum of 2/32 inch

11 / 50

the best kind of driver is a(n) __________ one.

A) Offensive

B) slow

C) sober

D) safety first-minded and defensive

12 / 50

One of the steps in shifting up is to

A) press the accelerator and shift to neutral.

B) push in the clutch and shift to the higher gear at the same time

C) increase engine and gear speed to the RPM required.

D) release the clutch and shift to neutral.

13 / 50

When backing a trailer,

A) turn and back toward the right side.

B) urn the steering wheel in the opposite direction you want to go.

C) use the highest reverse gear.

D) turn the steering wheel toward the direction you want to go.

14 / 50

What causes brakes to fade?

A) Frozen brake pads

B) Coasting

C) Using the brakes too lightly when going downhill

D) Slowing down from high speeds too quickly

15 / 50

If the radiator shutters freeze shut when driving in the winter, which of the following will occur?

A) The engine may overheat and stop.

B) The brakes will freeze.

C) It will be harder to steer.

D) Carbon monoxide will leak into your vehicle.

16 / 50

Which of the following emergency equipment should be carried in the truck at all times?

A) spare electrical fuses (if the truck has fuses)

B) reflective warning triangles or flares

C) All of the above

D) a fully charged 5 B:C fire extinguisher

17 / 50

Some vehicles have automatic transmissions. Why is it important to select a low range when going down grades?

A) To prevent a hydraulic brake failure

B) To prevent hydroplaning

C) To allow the transmission to shift up

D) To get greater engine braking

18 / 50

Your brakes have failed on a downgrade. Using an escape ramp, downshifting and ____________________ are helpful in slowing the vehicle.

A) using your horn

B) using the braking effect of the engine

C) shifting to a higher gear

D) countersteering

19 / 50

You are driving on a highway and your front tire has just blown out. You should

A) stay off the brake until you have slowed down.

B) keep driving until you find a service station.

C) brake hard.

D) pump the brakes.

20 / 50

If you have to steer away from what’s ahead in order to avoid a crash, which of the following is the best action to take?

A) Hit the brakes.

B) Turn, then countersteer once you have cleared the obstacle

C) Turn very sharply to clear whatever is in your way

D) Apply the brakes while turning.

21 / 50

When driving down a steep curve in the snow, you should

A) use the engine brake.

B) use the speed retarder.

C) brake hard.

D) turn as gently as possible.

22 / 50

Why don’t new trucks use the same gear for going down a hill as they would for going up a hill?

A) They have low friction parts.

B) They take up more fuel.

C) They have weaker engines.

D) They have more air drag.

23 / 50

At speeds below 40 mph, you need at—————for each————of vehicle length.

A) one second; 10 feet

B) one second; 20 feet

C) two seconds; 30 feet

D) two seconds; 10 feet

24 / 50

How often must drivers of trucks and truck tractors conduct a safety inspection?

A) Every 5 hours and after driving

B) Before driving

C) After driving

D) Before driving, every 3 hours during driving, and after driving

25 / 50

If the steering feels heavy or hard, it is probably a sign of

A) worn brakes.

B) tire problems.

C) engine problems.

D) battery failure.

26 / 50

What is black ice?

A) Oil

B) Freshly paved tar

C) Fog or mist

D) Clear ice

27 / 50

Which of the following is the best way to slow the vehicle when driving down a hill?

A) Shift to a higher gear.

B) Shift gears to neutral.

C) Apply heavy pressure on the brakes from time to time.

D) Downshift before the hill and keep light, continuous pressure on the brakes.

28 / 50

Which of the following is one of the best ways to deal with tailgaters in heavy traffic?

A) Turn on your tail lights.

B) Increase your following distance.

C) Brake quickly several times to flash your brake lights.

D) Speed up to increase the distance between you and the tailgater.

29 / 50

You are driving on slippery ice. Your rear-drive wheels lock and you begin to skid. Which of the following is the best action to take?

A) Take your foot off the accelerator and push in the clutch.

B) Shift to neutral.

C) Brake hard and pull off the road.

D) Take your foot off the accelerator and push the brake.

30 / 50

What are the three types of safety equipment that you must have before driving?

A) Spare fuses, tire chains and a fire extinguisher

B) Tire-changing equipment, spare fuses, and a fire extinguisher

C) An accident reporting kit, three red reflective triangles, and tire- changing equipment

D) Spare fuses, three red reflective triangles, and a fire extinguisher

31 / 50

Which of the following is true about empty trucks?

A) They are easier to steer.

B) They have better traction.

C) They require greater stopping distance.

D) They require less braking power.

32 / 50

What is the proper way to make a right turn when you are driving a long vehicle?

A) Turn wide as you complete the turn.

B) Turn quickly to stop other drivers from hitting you.

C) Keep the rear of the vehicle far away from the curb

D) Turn wide to the left as you start the turn.

33 / 50

You should inspect the tires every _________ when driving in very hot weather.

A) one hour or every 50 miles

B) three hours or every 150 miles

C) four hours or every 400 miles

D) two hours or every 100 miles

34 / 50

The controlled braking method is used

A) by applying the brakes slowly.

B) to make the wheels lock.

C) when making large steering wheel movements

D) by applying the brakes as hard as you can without locking the wheels.

35 / 50

If you must pull over to the shoulder on a major highway, you should

A) use the controlled braking method.

B) keep one set of wheels on pavement, if possible.

C) brake quickly several times to flash your brake lights.

D) turn onto the shoulder without braking.

36 / 50

To go down a long, steep hill you should

A) shift to a low gear before starting down the grade.

B) shift to a high gear before starting down the grade.

C) shift to a low gear after starting down the grade.

D) apply your brakes hard.

37 / 50

What is the correct placement of warning devices when parked on the shoulder of a one-way or divided highway?

A) At 10 feet, 100 feet, and 200 feet from the front of the vehicle

B) At 100 feet and 500 feet from the rear of the vehicle

C) At 10 feet, 100 feet, and 200 feet from the rear of the vehicle

D) At 100 feet and 500 feet from the front of the vehicle

38 / 50

You are stopped on an incline. How do you keep from rolling back?

A) Pump the accelerator hard

B) Put on the parking brake

C) Engage the clutch

D) Shift to neutral

39 / 50

A broken coolant hose while driving

A) increases the chances of tire failure.

B) causes the air-conditioner to fail.

C) can cause a fire

D) causes the heater to fail.

40 / 50

Which of the following statements is true about alcohol?

A) A few beers are the same as a few shots of whiskey.

B) Some people are not affected by alcohol

C) If you eat a lot first, you will not get drunk

D) Alcohol increases your ability to drive.

41 / 50

You are driving on a rainy day and the drive wheels begin to spin. To keep control of the vehicle, which of the following is the best action to take?

A) Take your foot off the accelerator

B) Steer to the left or right

C) Brake hard

D) Accelerate slightly

42 / 50

You wish to turn left from one multilane two-way street into another multilane two-way street. Which of the figures below shows how the turn should be made?

A) Figure b

B) Figure A

C) Figure d

D) Figure c

43 / 50

You are stopped on the shoulder of a curve that prevents approaching traffic from seeing your vehicle. How far back should you place your last warning device?

A) 10 feet

B) 500 feet

C) 200 feet

D) 100 feet

44 / 50

f one-fourth of a multileaf spring is missing, which of the following is most likely to happen?

A) It will make it hard to steer.

B) It will have no effect.

C) It will put the vehicle out of service.

D) It will cause a pop-pop-pop sound.

45 / 50

You are driving a large vehicle that cannot make a right turn without swinging into another lane. Which of the following figures shows the correct way to make the turn?

A) Figure A

B) Figure D

C) Figure B

D) Figure C

46 / 50

he proper distance to use high beams is at least _______________ away from an approaching vehicle.

A) 500 feet

B) 1,000 feet

C) 25 feet

D) 50 feet

47 / 50

Controlled braking is

A) releasing the brakes slowly.

B) jamming on the brakes.

C) braking so that the wheels lock

D) stab braking lock.

48 / 50

Which of the following is true about overhead clearance?

A) Repaving or packed snow increases the clearance height.

B) A loaded truck is higher than an empty one.

C) An empty van is higher than a loaded van.

D) Posted heights are always correct.

49 / 50

Which of the following should you examine when inspecting the front of your vehicle?

A) Condition of steering system

B) Condition of brakes

C) All of the above

D) Condition of shock absorbers

50 / 50

Why must you tab or keep shipping papers related to hazardous materials in special places?

A) Because they must be delivered first

B) Because you must know what products you can load together, and which you cannot

C) In case there are no placards

D) f the driver is in an accident and cannot speak, people must know the hazards involved.

Your score is

The average score is 71%

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