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California CDL DMV Knowledge Test Class B 1

Take 4 practice tests for CDL is the best way to prepare for your California DMV exam is by taking our free practice tests. The following question are from real California DMV practice test. More than 95% people pass a DMV exam when practice at DMV Practice Test.

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1. You may not consume alcohol within ____ of going on duty.
One hour
Two hours
Four hours

Commercial vehicle drivers are prohibited from consuming any intoxicating beverage, regardless of its alcohol content, within four hours of going on duty.

2. A tread depth of ____ should be in every major groove of a tire that is not in the front of a commercial motor vehicle.
1/32 of an inch
2/32 of an inch
4/32 of an inch

For safe operation, a commercial motor vehicle needs a tread depth of 4/32 of an inch in every major groove on the front tires, and a tread depth of 2/32 of an inch on other tires.

3. Why do large vehicles use air brakes?
Other brake systems squeak too loudly.
Air brakes are very effective systems.
Other braking systems are hard to come by.

If used and maintained properly, air brakes are a safe and effective way to stop large, heavy vehicles.

4. When backing with a trailer, you should begin by:
Turning the steering wheel in the direction of the turn.
Turning the steering wheel in the direction opposite of the turn.
Turning the wheel as sharply as possible.

When backing with a trailer, begin by turning the steering wheel in the direction opposite of the turn. Once the trailer starts to turn, reverse the direction of the steering wheel to follow the trailer.

5. While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.
5 mph
10 mph
15 mph

While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.

6. When backing with a trailer:
You should not back up in a straight line.
You should not correct drift until you are far off course.
You should frequently pull forward to reposition the vehicle.

When backing, you should pull forward to reposition your vehicle whenever needed. Drift should be corrected immediately by turning the steering wheel in the direction of the drift.

7. If involved in an accident, which of the following is not recommended?
Trying to move your vehicle to the side of the road
Caring for the injured
Driving away from the scene

When involved in an accident, you should protect the area, notify authorities, care for the injured, collect required information, and report the accident. You can lose your license for leaving the scene of an accident.

8. When leaving your vehicle:
The air brakes should be applied.
The parking brake should be applied.
Brakes should not be applied if the vehicle is left out of gear.

Parking brakes should be used whenever you park. If necessary, chock your wheels.

9. When backing up, follow a turning trailer by:
Changing nothing. The vehicle will naturally follow the trailer.
Changing the direction of the steering wheel.
Turning the steering wheel even harder in the direction that it is already turning.

When backing with a trailer, begin by turning the steering wheel in the direction opposite of the turn. Once the trailer starts to turn, reverse the direction of the steering wheel to follow the trailer.

10. By beginning a left turn before reaching the center of an intersection, you:
Will likely complete the turn satisfactorily.
May hit other vehicles with the left side of your vehicle.
Can expect other drivers to move their vehicles to accommodate your turn.

When planning to turn left at an intersection, make sure you have reached the center of the intersection before beginning the turn. If you turn too soon, off-tracking may cause the left side of your vehicle to hit another vehicle.

11. Cargo with a high center of gravity:
Can make a vehicle likely to tip over.
Is encouraged in inclement weather.
Is required on some roads.

Cargo with a high center of gravity makes a vehicle more likely to tip over than cargo with a low center of gravity. For this reason, it is important that the weight of cargo be distributed as low as possible.

12. If a tire fails, you should:
Use the brakes.
Stay off the brakes.

Braking after a tire fails can result in a loss of control. Stay off your brakes, if possible, until your vehicle has slowed considerably.

13. When driving in winter, which of the following should receive extra attention in a pre-trip inspection?
Coolant and antifreeze levels
The air conditioning unit
The oil pressure

When doing a pre-trip inspection during the winter, you should pay extra attention to the coolant level and amount of antifreeze; the defrosting and heating equipment; the wiper blades and windshield washer; the tires and tire chains; the lights and reflectors; the windows and mirrors; the hand holds, steps, and deck plates; the radiator shuttles and winterfront; and exhaust system.

14. When braking with ABS, you should:
Pump the brake pedal.
Brake normally.
Brake harder than you would with a different braking system.

When braking a vehicle equipped with an Anti-Lock Braking System (ABS), you should not brake any differently than you would if driving a vehicle with a different braking system.

15. A truck tractor built after March 1, 1997 must be equipped with:
An Anti-Lock Braking System (ABS).
A flag.
Hydraulic brakes.

Truck tractors with air brakes built on or after March 1, 1997 are required to be equipped with Anti-Lock Braking Systems (ABS).

16. A pre-trip inspection should include:
A check of the engine oil level.
Removing coolant.
Washing the tire rims.

When examining the engine compartment during a pre-trip inspection, you should check the engine oil level, the radiator coolant level, and the condition of the hoses.

17. Rough acceleration:
Is a good way to stay awake on long trips.
Is distracting.
Can cause mechanical damage.

Rough acceleration can cause mechanical damage, so be sure to accelerate smoothly and gradually.

18. If you are being tailgated while driving a large vehicle, do all of the following, except:
Reduce your speed gradually.
Increase your following distance.
Increase your speed.

If you find yourself being tailgated by another driver, you should increase your following distance and avoid making quick moves. Increasing your speed may only result in the other driver continuing to tailgate you at a higher speed. Do not turn on your taillights or flash your brake lights at the other driver.

19. If an unusual noise or feeling occurs in a vehicle while it is being driven, the driver should:
Assume it is not a concern and continue driving.
Hope the vehicle does alright until it is switched to another driver.
Check the situation to determine the proper solution.

If you see, hear, smell, or feel anything while driving that does not feel right, you should have it checked out.

20. When driving, you should stop every ____ to take a break to avoid becoming too tired.
Half hour
Two hours
Six hours

To reduce the risk of becoming fatigued on a long trip, you should stop to take a break at least once for every two hours or 100 miles driven.

21. If asked by a law enforcement officer to take a test to determine your blood alcohol concentration (BAC):
You can refuse to take the test without a penalty.
You can refuse taking the test but will be required to pay a $50 fine.
You will lose your CDL if you refuse to take the test.

Most states have an Implied Consent Law, which means that by driving a vehicle on the state's roads, you have agreed to undergo a drug or alcohol test if a police officer asks you to do so. If you refuse to submit to a test, you will lose your operating privileges. Make sure you are aware of the laws for every state in which you drive.

22. Pre-trip inspections are:
Needed only for trips longer than 100 miles in length.
Required by law.

Federal and state laws require drivers to inspect their vehicles before every trip, regardless of length.

23. Which of the following is the best advice for driving in fog?
Try not to drive in fog.
Use your high beam headlights.
Turn off your lights.

Driving in fog is always dangerous and should be avoided entirely if at all possible. If you must drive in fog, be sure to turn on your low beam headlights and fog lights, even during the daytime.

24. If you realize you may be running late to your destination, you should:
Speed up.
Get upset.
Deal with it and drive at a safe speed.

To reduce the risk of developing aggressive driving behavior, you should take measures to manage your stress. One strategy to do this is to simply take a deep breath and accept your circumstances if you realize you will be late to your destination.

25. In hot weather, spots on the pavement where tar is bleeding:
Are very slippery.
Offer the same amount of traction as the rest of the roadway.
Offer more traction than the rest of the roadway.

Tar in road pavement often rises to the surface of the road, or "bleeds," in very hot weather. Watch for such areas because they can be very slippery.

26. If driving on a surface with poor traction, a driver should accelerate slowly:
Because it is always good to accelerate slowly.
To keep from losing control of the vehicle.
So that they do not accelerate faster than the vehicle ahead.

To avoid a loss of control, you should accelerate slowly when driving in poor-traction conditions, such as rain or snow.

27. An Individual Vehicle Distance Record (IVDR) does not need to include which of the following?
The dates of a trip
The total distance traveled
The number of vehicles passed

An Individual Vehicle Distance Record (IVDR) must include information about the distance traveled by a vehicle and the amount of fuel purchased. The required distance information includes the dates of a trip and the total distance traveled by the vehicle.

28. When trying to put out an electrical fire, you should:
Use water.
Use a B:C extinguisher.
Use an X extinguisher.

B:C fire extinguishers are designed to work on electrical fires and burning liquids. Don't pour water on an electrical fire.

29. Wheels with welding repairs are:
Safe to be used if the repairs were done by a professional.
Safe to be used if the repair seems solid.
Not safe to be used.

Wheels or rims that have had welding repairs are not safe for use. They should be replaced before the vehicle is taken on the road.

30. A poor balance of weight in a trailer:
Can make handling unsafe.
Improves traction.
Increases fuel efficiency.

Poorly balanced weight in a trailer can make handling unsafe. For example, either too little or too much weight on the front axle can make a vehicle difficult to steer. Weight should be distributed evenly from front to back and from side to side. It should be distributed as low as possible.

31. What is a tire load?
The minimum safe weight a tire can carry
The maximum safe weight a tire can carry
The weight of a tire

Tire load is defined as the maximum safe weight that a tire can carry at a specified pressure.

32. Cargo being transported should be checked:
Only before the trip.
Before the trip and again within the first 50 miles of the trip.
Only by the loading personnel.

Cargo should be inspected before beginning a trip, within the first 50 miles of the trip, and every three hours or 150 miles traveled thereafter. Cargo should be inspected every time the driver stops to take a break. The driver of a truck transporting cargo is responsible for the cargo being safely secured throughout the trip.

33. If driving through flowing water or a large puddle, you should:
Increase your speed.
Gently apply the brakes.
Try to stop in the water.

It is best to avoid driving through large puddles or moving water. If there is no way to avoid driving through water, you should slow down, shift into a low gear, and gently apply the brakes. Pressing linings against the brake drums or discs will keep water, mud, silt, and sand from getting inside the brake mechanisms.

34. When operating a vehicle with a dual air brake system, the driver should:
Let the vehicle warm up before driving to ensure that the fuel reaches the engine.
Let the air compressor build up a minimum of 100 psi pressure in the primary and secondary systems before driving.
Begin driving just after the vehicle starts.

Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems. Watch the air pressure gauges to monitor the pressure levels.

35. When exiting a vehicle, it is important to maintain ____ with your vehicle at all times.
Three points of contact
Four points of contact
Two points of contact

As you exit your vehicle during the basic vehicle control skills test, you must face the vehicle and maintain three points of contact at all times. If your testing vehicle is a bus, you must maintain contact with the handrail. Exiting the vehicle incorrectly may result in automatic failure of the basic control skills test.

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