CDL General Knowledge Test (50 Questions Answers)

CDL General Knowledge Test (50 Questions Answers): If you are preparing to take the Commercial Driver’s License Exam, you’ve visited the right page. Our CDL General Knowledge Test (50 Questions) is an essential part of your preparation for the exam. It’s been proven that the more questions you answer before taking the exam, the better you will ultimately do on the final test.

If you have enough time to prepare, take each test on separate days and bring them to a quiet room, under simulated test conditions. When you’re done, check your answers and then check your score. As you go through the CDL Quiz, you will find that there are some areas that may require additional review, based on your previous knowledge or the results of the CDL practice tests.

CDL General Knowledge Test (50 Questions)

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

185

CDL General Knowledge Test 5

1 / 50

f you are transporting livestock,

A) give livestock enough room to roam freely.

B) there is always a high center of gravity.

C) use false bulkheads with less than a full load.

D) rollover is less likely.

2 / 50

Which of the following statements about tank vehicles is true?

A) The term “tank vehicle” refers only to those vehicles having a permanently attached tank.

B) All tank vehicles have some sort of bulkhead or baffle.

C) Tank vehicles transport liquids only.

D) Special skills are required to haul liquid tanks.

3 / 50

Which of the following statements about unbaffled or “smooth bore” liquid tankers is NOT true?

A) Food products will most likely be transported in an unbaffled liquid tank

B) Forward and back liquid surge is reduced

C) You must be extremely cautious, especially when starting and stopping.

D) There is nothing inside the tank to slow down the flow of liquid

4 / 50

When driving baffled liquid tanks,

A) here is no risk involved in taking curves or making sharp turns at the posted limits.

B) forward and backward liquid surge is controlled.

C) there is no risk of rollover.

D) bulkheads are included which stop side to side liquid surge.

5 / 50

Shippers must write the name of the hazard class of hazardous products

A) only on the special-fitting tags for the containers

B) on the shipping papers and on the diamond-shaped labels or special tags on the container.

C) only on the shipping papers.

D) only on the diamond-shaped labels on the containers.

6 / 50

You should use your mirrors to check

A) traffic gaps when merging.

B) All of the above

C) the condition of tires.

D) where the rear of your vehicle is while turning.

7 / 50

To correct a drive-wheel braking skid you should

A) brake harder.

B) turn slowly

C) keep your foot off the clutch.

D) countersteer.

8 / 50

For cargo, blocking is

A) unattached to the cargo deck.

B) needed in the front of a piece of cargo only

C) used in the front, back and/or sides of a piece of cargo

D) shaped to fit loosely over the cargo

9 / 50

Which of the following is an effect of drinking and driving?

A) All of the above

B) Driving in the wrong lane

C) Running stop signs

D) Making quick, jerky movements

10 / 50

Two possible causes of tire fires are

A) short circuits and duals that touch.

B) improperly loaded cargo and driver smoking.

C) improper fueling or loose fuel connections.

D) under-inflated tires and duals that touch.

11 / 50

You must keep shipping papers for hazardous materials

A) in a pouch on the driver’s door.

B) in the glove compartment.

C) under the passenger’s seat.

D) with the hazardous materials.

12 / 50

Which of the following about covering cargo is NOT true?

A) You need to protect the cargo from the weather.

B) You need to protect people from spilled cargo.

C) Flapping covers need not be tied down as long as the bulk of the cargo is covered.

D) You should look at your cargo in the mirrors often while driving.

13 / 50

A skid happens when tires lose their grip on the road. To prevent skidding, you should

A) turn the wheel sharply for all turns.

B) brake hard at all stops.

C) adjust to conditions while driving.

D) accelerate to give power to the drive wheels.

14 / 50

Which of the following contains more alcohol?

A) A 12-ounce mug of beer with an alcohol content of 5% by volume

B) A 1 1/2nce shot of 80-proof liquor

C) All three contain the same amount of alcohol.

D) A 5-ounce glass of wine with an alcohol content of 12% by volume

15 / 50

How far ahead should a driver look ahead of the vehicle while driving?

A) 1-2 seconds

B) 18-21 seconds

C) 12-15 seconds

D) 5-8 seconds

16 / 50

Dry bulk tanks and hanging meat

A) handle better than most cargo on sharp turns.

B) are unstable loads.

C) do not require special care.

D) have low centers of gravity.

17 / 50

To prevent truck fires, you should inspect your vehicle

A) before, during, and after the trip.

B) before and after the trip.

C) after the trip only.

D) before the trip only.

18 / 50

f an oncoming driver has suddenly drifted into your lane or if an obstacle suddenly blocks your path, you should

A) move to the left.

B) apply brakes slowly and signal for a lane change.

C) move to the right.

D) brake immediately.

19 / 50

To stop quickly and safely, you can use which of the controlled braking methods?

A) Apply the brakes as hard as you can to lock the wheels.

B) Apply the brakes but keep them released before and after you make steering adjustments.

C) Apply the brakes as hard as you can without locking the wheels.

D) Apply the brakes and make large steering adjustments.

20 / 50

In the event of an engine fire,

A) always open the hood and shoot extinguishers through louvers or from the underside of the vehicle.

B) try to keep the hood closed and shoot extinguishers through louvers or from the underside of the vehicle.

C) always open the hood to release the fire.

D) keep the engine running and use extinguishers.

21 / 50

Which of the following statements is NOT true about an overloaded vehicle?

A) The vehicle will have to go very slowly on upgrades.

B) All of the above

C) The vehicle’s stopping distance decreases.

D) The vehicle may gain too much speed on downgrades.

22 / 50

f you do not have a Hazardous Materials Endorsement on your Commercial Driver License, you can

A) only transport liquid hazardous materials.

B) not transport any type of hazardous material.

C) drive a vehicle that carries hazardous materials if it does not require placards.

D) transport hazardous materials if your employer lets you.

23 / 50

Which of the following statements about loading heavy or dense liquid is true?

A) The weight of the actual liquid does not matter.

B) Heavy or dense liquids do not expand.

C) You must be aware of legal weight limits

D) Tanks carrying heavy liquids can sometimes be filled completely.

24 / 50

Poor weight balance can make vehicle handling unsafe. Hard steering is caused by

A) underloaded front axles.

B) a high center of gravity.

C) too much weight on the steering axle.

D) too little weight on the driving axles.

25 / 50

To turn quickly and safely in the event of a traffic or vehicle emergency, you should be prepared to countersteer. This means you turn the wheel

A) the opposite direction of the obstacle.

B) to the left of the obstacle.

C) away from the obstacle and then back in the other direction.

D) to the right of the obstacle.

26 / 50

Since you cannot inspect sealed loads, you

A) must be lower than weight limits by 50 pounds.

B) therefore need special tie down devices.

C) can exceed gross weight and axle weight limits.

D) should therefore check that you do not exceed gross weight and axle weight limits.

27 / 50

Which of the following is a good thing to do when driving at night?

A) Look directly at oncoming headlights briefly.

B) Keep your instrument lights bright.

C) Wear sunglasses to reduce headlight glare.

D) Keep your speed slow enough that you can stop within the range of your headlights.

28 / 50

Which of the following statements about a vehicle with a high center of gravity is true?

A) The cargo is evenly distributed and as low as possible.

B) The vehicle is less dangerous on curves.

C) The vehicle is less likely to tip over.

D) The cargo should be rearranged so that the heaviest parts of the cargo are under the lightest parts.

29 / 50

Possession or use of drugs while on duty is prohibited by law except when

A) using amphetamines.

B) using over-the-counter drugs

C) your doctor informs you that the certain drug prescribed will not affect safe driving abilities.

D) using alcohol.

30 / 50

Outage is

A) a full liquid tanker.

B) caused by liquid surge.

C) the space allotted for expanding liquids.

D) the weight of the liquid in transit

31 / 50

A tank vehicle with a high center of gravity

A) cannot turn over at the speed limit posted for curves.

B) is top-heavy, but not easy to rollover.

C) should take highway curves or on-ramp/off-ramp curves well below the posted speeds.

D) should take highway curves or on-ramp/off-ramp curves at least five miles above the posted speed.

32 / 50

The Gross Combination Weight Rating is the

A) total weight of a single vehicle plus its load.

B) total weight of a powered unit plus trailer(s) plus the cargo.

C) maximum total weight of a power unit plus trailer(s) plus the cargo as specified by the manufacturer.

D) maximum total weight of a single vehicle plus its load specified by the manufacturer.

33 / 50

if you are driving a long distance, you should

A) avoid short breaks, but keep the window open.

B) take a short break once or twice during the trip when you are feeling tired or drowsy.

C) stop often and take short breaks before you feel really drowsy or tired.

D) do some physical exercises after the trip.

34 / 50

When transporting cargo, inspect the materials and securing devices

A) before the trip, within 50 miles after beginning the trip, after every 3 hours or 150 miles, and during every driving break.

B) before and after the trip.

C) before the trip only.

D) within 50 miles after beginning the trip and during every driving break.

35 / 50

____________ protect you from your cargo in case of collision and should be inspected for good condition.

A) Front-end header boards

B) Blocking devices

C) Tie downs

D) Bracing devices

36 / 50

Which of the following is true about drinking and driving?

A) Alcohol will reduce your ability to drive.

B) Alcohol increases your ability to drive farther.

C) A drink will wake up a sleepy driver.

D) Coffee and a little fresh air will help sober up a driver who is about to drive.

37 / 50

Which of the following should you NOT do if you suspect that one of your vehicle’s tires has blown out?

A) Keep driving until you are certain it was one of your vehicle’s tires that blew.

B) Hold the steering wheel firmly.

C) Check all tires after stopping.

D) Stay off the brake.

38 / 50

When a front-wheel skid occurs, the only way to stop the skid is to

A) brake hard.

B) let the vehicle slow down.

C) increase acceleration.

D) turn sharply.

39 / 50

Which of the following statements about driving an over-length, over- width, and/or over-weight load is NOT true?

A) Special equipment may be necessary.

B) You do not need a special permit.

C) Driving is usually limited to certain times.

D) You may require a police escort.

40 / 50

n some emergencies, you may have to drive off the road and onto the shoulder in order to avoid collision with another vehicle. If possible, you should avoid

A) keeping one set of wheels on the pavement.

B) coming to a complete stop before returning to the road.

C) All of the above

D) using the brake until your speed has dropped to about 20 mph

41 / 50

Which of the following should you NOT do in the event of air brake failure where there was a major air leak in the system?

A) Find an escape route

B) Pump the brakes

C) Shift down

D) Use the parking or emergency brake

42 / 50

A coupling device capacity is the

A) maximum weight the device can pull and/or carry.

B) weight transmitted to the ground by one axle or one set of axles.

C) manufacturer’s weight capacity rating of the suspension system.

D) maximum safe weight a tire can carry at a specified pressure.

43 / 50

In the event of a cargo fire in a van or box trailer, you should

A) park close to the road so other vehicles can see the danger and call for assistance.

B) drive to the closest service station for assistance.

C) keep the doors open

D) keep the doors shut.

44 / 50

Which of the following statements about tie downs is true?

A) The combined strength of all cargo tie downs must be strong enough to lift one-and-a-half-times the weight of the piece of cargo tied down

B) Cargo should have at least one tie down for each 20 feet of cargo.

C) They go from the upper part of the cargo to the floor and/or walls of the cargo compartment.

D) Tie downs can be of any type or strength.

45 / 50

For electrical fires and burning liquids, use

A) an A:B:C or B:C type fire extinguisher.

B) whatever is available at the time.

C) water

D) a B:C type fire extinguisher only.

46 / 50

You are driving a vehicle when two cars collide a short distance ahead of you. In order to safely avoid the accident, you should

A) grip the wheel firmly with both hands and turn only the amount of space needed to clear whatever is in your way

B) make a sharp turn to clear the accident area

C) always apply the brakes immediately

D) urn quickly with one hand on the wheel and one hand on the horn

47 / 50

If your vehicle is involved in an accident, try to

A) get it to the side of the road.

B) honk your horn to warn other vehicles.

C) keep one empty lane between your vehicle and other traffic.

D) stop all traffic in other lanes.

48 / 50

You have been driving for a long time and you are feeling tired. What should you do?

A) Make an early stop and sleep or pull off the road and nap.

B) Take an over-the-counter drug that will keep you awake.

C) Take a half-hour coffee stop

D) Push on until your next stop and rest.

49 / 50

You see an accident on the road and wish to help. The steps you take to prevent further damage or injury are: protect the area, care for the injured, and

A) notify authorities.

B) always move the severely injured person(s) away from the accident.

C) park your vehicle near the accident.

D) keep the injured person(s) cool.

50 / 50

The Federal Hazardous Materials Table names materials that are hazardous. If you are transporting any of these materials,

A) only the shipper should know.

B) only the driver should know

C) the shipper and the driver should know.

D) everyone who handles the material should know.

Your score is

The average score is 78%

CDL Knоwlеdgе Test (50 Questions Each)

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Hazardous Material

Passenger Endorsement

Metal Coil Endorsement

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