CDL General Knowledge Practice Test 2026: الاختبار التدريبي 3

1. السؤال 1 من 25

   Is a radar detector allowed in a commercial motor vehicle?

   • AYes, if it is turned off
   • BYes, on interstate highways
   • COnly in states that allow them
   • DNo
   أظهر الإجابة

   الإجابة: D. No

   A driver may not use a radar detector in a CMV or drive a CMV that has one in it.

2. السؤال 2 من 25

   In the seven-step inspection method, what is the first step?

   • AVehicle overview
   • BCheck the signal lights
   • CCheck the brakes
   • DCheck the engine compartment
   أظهر الإجابة

   الإجابة: A. Vehicle overview

   Step 1 is the vehicle overview: general condition, leaning, leaks, hazards nearby and the last inspection report.

3. السؤال 3 من 25

   Before you check the engine compartment, what should you do?

   • ATurn on the high beams and flashers
   • BStart the engine and let it warm up
   • CSet the parking brake or chock the wheels
   • DRelease the parking brake fully
   أظهر الإجابة

   الإجابة: C. Set the parking brake or chock the wheels

   Step 2 starts by making sure the vehicle cannot move: set the parking brake and/or chock the wheels.

4. السؤال 4 من 25

   In which step of the seven-step inspection do you check tires, wheels, suspension and brakes on each side of the vehicle?

   • AStep 6, the signal lights
   • BStep 1, the overview
   • CStep 3, inside the cab
   • DStep 5, the walkaround
   أظهر الإجابة

   الإجابة: D. Step 5, the walkaround

   The walkaround in step 5 covers lights, tires, wheels, suspension, brakes, cargo securement and fuel tanks on every side.

5. السؤال 5 من 25

   What is the last step of the seven-step inspection?

   • ARead the last inspection report
   • BCheck the engine oil
   • CWalk around the vehicle
   • DStart the engine and check the brakes
   أظهر الإجابة

   الإجابة: D. Start the engine and check the brakes

   Step 7 is to start the engine and check the brake system, including the parking brake and service brake tests.

6. السؤال 6 من 25

   What is the minimum tread depth for the front (steering) tires?

   • A4/32 inch in every major groove
   • B1/32 inch in every major groove
   • C6/32 inch in every major groove
   • D2/32 inch in every major groove
   أظهر الإجابة

   الإجابة: A. 4/32 inch in every major groove

   Front tires need at least 4/32 inch of tread in every major groove.

7. السؤال 7 من 25

   What is the minimum tread depth for tires that are not on the front axle?

   • A4/32 inch
   • B6/32 inch
   • C2/32 inch
   • D1/32 inch
   أظهر الإجابة

   الإجابة: C. 2/32 inch

   Tires other than the front tires need at least 2/32 inch of tread in every major groove.

8. السؤال 8 من 25

   How much play in the steering wheel can make the vehicle hard to steer?

   • AMore than 45 degrees (about 8 inches on the rim)
   • BAny play at all, even less than a quarter inch
   • CMore than 2 degrees (about half an inch on the rim)
   • DMore than 10 degrees (about 2 inches on a 20-inch wheel)
   أظهر الإجابة

   الإجابة: D. More than 10 degrees (about 2 inches on a 20-inch wheel)

   Steering wheel play of more than 10 degrees can make it hard to steer.

9. السؤال 9 من 25

   How do you check hydraulic brakes during the inspection?

   • ADrive at 30 mph and brake hard; the truck should stop straight
   • BPump three times, then hold for five seconds; the pedal should not move
   • CHold the pedal for one minute with the engine off; it should sink
   • DPress the pedal once quickly; it should spring back up right away
   أظهر الإجابة

   الإجابة: B. Pump three times, then hold for five seconds; the pedal should not move

   With hydraulic brakes, pump three times and hold for five seconds. The pedal should stay firm.

10. السؤال 10 من 25

    How do you test the service brakes at the end of the inspection?

    • AMove forward at about 5 mph and brake firmly
    • BApply the parking brake while moving
    • CPump the pedal several times while parked
    • DDrive at highway speed and brake hard
    أظهر الإجابة

    الإجابة: A. Move forward at about 5 mph and brake firmly

    Go forward slowly, about 5 mph, then brake firmly. Note any pulling or delay.

11. السؤال 11 من 25

    How do you check that the parking brake will hold?

    • APush against the truck by hand from behind
    • BSet it and gently pull against it in a low gear
    • CRelease it at highway speed and feel the pull
    • DPark on a steep hill and walk away to see
    أظهر الإجابة

    الإجابة: B. Set it and gently pull against it in a low gear

    With the parking brake on, try to pull forward gently in a low gear. The vehicle should not move.

12. السؤال 12 من 25

    Which emergency equipment must a truck carry?

    • AA spare tire, a tow strap and jumper cables
    • BA fire extinguisher, warning devices and spare fuses
    • CSnow chains, a jack and a tire iron
    • DA first aid kit, a shovel and a flashlight
    أظهر الإجابة

    الإجابة: B. A fire extinguisher, warning devices and spare fuses

    Required emergency equipment is a charged, rated fire extinguisher, warning devices such as three reflective triangles, and spare fuses unless the vehicle has circuit breakers.

13. السؤال 13 من 25

    Your oil pressure gauge shows low or falling pressure while you drive. What should you do?

    • ASpeed up to raise the pressure
    • BTurn off the gauge
    • CKeep driving and check it at your next stop
    • DStop as soon as it is safe
    أظهر الإجابة

    الإجابة: D. Stop as soon as it is safe

    Low or changing oil pressure can mean engine damage. Stop right away when it is safe.

14. السؤال 14 من 25

    You find defects listed on the previous driver's inspection report. When should you sign the report?

    • AOnly if the defects were repaired or certified as not needing repair
    • BOnly at the end of your own trip, after you drive the vehicle
    • CAlways, before you start the engine, whatever the report says
    • DNever; only a mechanic may sign an inspection report
    أظهر الإجابة

    الإجابة: A. Only if the defects were repaired or certified as not needing repair

    Review the last report and sign it only when the defects listed were certified as repaired or not needing repair.

15. السؤال 15 من 25

    When you must back up, which way should you back if you have a choice?

    • AInto traffic
    • BUphill
    • CToward the driver's side
    • DToward the right side
    أظهر الإجابة

    الإجابة: C. Toward the driver's side

    Backing toward the driver's side lets you see better.

16. السؤال 16 من 25

    What does G.O.A.L. mean when backing?

    • AGet Out And Look
    • BGear Options Are Limited
    • CGo Only At Low speed
    • DGive Others A Lane
    أظهر الإجابة

    الإجابة: A. Get Out And Look

    Before and while backing, get out and look at your path if you are not sure what is behind you.

17. السؤال 17 من 25

    How should you back a large vehicle?

    • AQuickly, to finish the move
    • BIn the highest reverse gear
    • CSlowly, in the lowest reverse gear
    • DIn neutral, letting it roll
    أظهر الإجابة

    الإجابة: C. Slowly, in the lowest reverse gear

    Back slowly in the lowest reverse gear so you can correct steering errors and stop quickly.

18. السؤال 18 من 25

    You are backing a trailer and want the trailer to go to the left. Which way do you turn the steering wheel?

    • AHold it straight
    • BTurn it left, then quickly right
    • CTo the left
    • DTo the right
    أظهر الإجابة

    الإجابة: D. To the right

    When backing a trailer, turn the steering wheel in the opposite direction from where you want the trailer to go.

19. السؤال 19 من 25

    Which kind of manual transmission usually needs double clutching?

    • AAn unsynchronized transmission
    • BAn automatic transmission
    • CA synchronized transmission
    • DAny transmission in top gear
    أظهر الإجابة

    الإجابة: A. An unsynchronized transmission

    Unsynchronized manual transmissions usually need double clutching. Synchronized ones do not.

20. السؤال 20 من 25

    When should you downshift?

    • AAfter speed builds on a downgrade
    • BIn the middle of a curve
    • CBefore a downgrade and before a curve
    • DOnly when the engine stalls
    أظهر الإجابة

    الإجابة: C. Before a downgrade and before a curve

    Shift down before a downgrade and before a curve so you stay in control.

21. السؤال 21 من 25

    What should you do with a retarder on wet, icy or snowy roads?

    • ASet it to the highest level
    • BUse it instead of the brakes
    • CTurn it off
    • DUse it only in curves
    أظهر الإجابة

    الإجابة: C. Turn it off

    Retarders can make the drive wheels skid on slippery roads, so turn them off.

22. السؤال 22 من 25

    Your drive wheels start to spin as you pull away. What should you do?

    • AApply the trailer brakes
    • BTake your foot off the accelerator
    • CShift into a higher gear quickly
    • DPress harder on the accelerator
    أظهر الإجابة

    الإجابة: B. Take your foot off the accelerator

    If the drive wheels spin, ease off the accelerator to regain traction.

23. السؤال 23 من 25

    How far ahead do most good drivers look?

    • A30 to 40 seconds
    • B12 to 15 seconds
    • C3 to 5 seconds
    • D1 to 2 seconds
    أظهر الإجابة

    الإجابة: B. 12 to 15 seconds

    Looking 12 to 15 seconds ahead gives you time to spot hazards and plan.

24. السؤال 24 من 25

    At highway speed, looking 12 to 15 seconds ahead means looking about how far?

    • AAbout 2 miles
    • BAbout 100 feet
    • CAbout one city block
    • DAbout a quarter of a mile
    أظهر الإجابة

    الإجابة: D. About a quarter of a mile

    At lower speeds 12 to 15 seconds is about one block. At highway speeds it is about a quarter of a mile.

25. السؤال 25 من 25

    How do convex (curved) mirrors make objects look?

    • ASmaller and farther away than they really are
    • BCloser but the right size
    • CLarger and closer than they really are
    • DExactly as they are
    أظهر الإجابة

    الإجابة: A. Smaller and farther away than they really are

    Convex mirrors show a wider area, but things look smaller and farther away.

لوحة المفاتيح: 1–4 للإجابة، وEnter للسؤال التالي.

الاختبار الحقيقي: Varies by state; usually 50 questions, with 40 correct needed (80%)