california
CDL Practice Test

This site is designed to help aspiring commercial drivers practice for their State of California Department of Motor Vehicles CDL test. You can take these free California CDL practice tests as many times as you would like. Questions on these tests come from the various commercial driver license topics that are represented in the California CDL handbook. You will be presented with 40 questions and you must answer 34 questions correctly to pass. There is a 50-minute time limit. You may not go back once you answer a question. Click the "Start Test" button below to begin.

1 / 40

The most stable tanker shape is:

Round

Elliptical

Cylindrical

Square

2 / 40

Tires should should be replaced:

if the tread depth on your front tires is less than 4/32 deep

when the tread separates

when there are broken valve stems

all of these answers are correct

3 / 40

How do you supply air to the trailer tanks?

by pushing in the trailer air supply valve

by connecting the red and blue lines

by pulling out the trailer air supply valve

by connecting the service line glad hand

4 / 40

At 55 miles-per-hour it takes about 6 seconds to stop a fully loaded truck and the braking distance is:

about two car lengths

about 1/4 mile

about the length of a football field or 100 yards

about two truck lengths

5 / 40

It takes special care to drive tankers with liquid in them because:

The movement of the liquid even when the truck is stopped.

The low center of gravity of the load.

The baffles create odd rocking motions.

The high center of gravity of the load.

6 / 40

What is the purpose of cladding in a tanker?

It controls the temperature of the cargo.

It protects the cargo from changes in temperature.

It eliminates liquid surge.

It protects the tanker form any corrosive cargo.

7 / 40

Select the true statement in regards to the braking power of spring brakes.

the braking prower increases when the brakes are hot

it will not be affect by the condition of the service brakes

it depends on the adjustment of the service brakes

braking power can only be tested by licensed mechanics

8 / 40

Is this statement true or false: You do not need to use the parking brake if are leaving your vehicle for a short amount of time.

only when the vehicle has over 25,000 miles on it

only when the vehicle has over 60,000 miles on it

true

false

9 / 40

Should your air compressor stop working:

the brakes will lock up on you immediately

there will still be air pressure left in the air tanks

there will be no affect to your brakes

you will lose your ability to brake immediately

10 / 40

The air leakage rate for combination vehicles should not be more than _ psi a minute.

11 / 40

What is the stopping distance for a tractor trailer that is traveling at 55 mph on dry pavement?

about 300 feet which is about a football field length

about 200 feet which is 2/3 of a football field

about 600 feet with is about two football field lengths

about 150 feet which is 1/2 of a football field

12 / 40

This object should be free of shiny treads, rust, free of cracks and distortions.

Bolt spacers

Rims

None of the answers listed

Lug nuts

13 / 40

What keeps air in the tanks should the air compressor develop a leak?

the tractor relay valve

the engine protection valve

the one-way check vavle

the air compressor

14 / 40

What is the purpose of a baffle?

It makes it easier to clean the tanker out.

It controls the surge of liquid forward and backwards.

It allows you to haul loads that are mixed.

It stops side to side surging.

15 / 40

What is most likely to occur when the front wheels begin to skid?

You will continue heading in a straight line and moving forward no matter what direction you turn the steering wheel.

All answers listed.

The power of the surge will disconnect the tank from the truck.

A roll over will occur.

16 / 40

You downshift automatic transmissions ______.

half way down a hill

at the bottom of a hill

before going down a hill

none of these answers are correct

17 / 40

When does stab braking occur?

when the wheels lock up, release the brakes

all of these answers are correct

apply pressure all the way on the brake pedal

when the wheels start rolling, apply the brakes

18 / 40

You should follow the posted speed limits for curves and be aware of:

The higher center of gravity on a tank truck.

The posted speed limit may be too high for safety.

All answers listed.

A rollover may occur even when driving at the posted speed limit.

19 / 40

What should you do if you start a trailer skid?

slowly apply a firm pressure to the brakes

use your trailer hand brake

quickly step on the brakes

release the brakes to get traction back

20 / 40

The golden rule for school buses when approaching and crossing railroad tracks is:

Stop, go, and stop.

Stop, look, and turn on the radio lights overhead.

None of these answers are correct.

Stop, look, and listen.

21 / 40

How do you make sure the trailer height is correct before coupling?

you do not need to do a visual check

visually check that the lead trailer is higher than the fifth wheel so that the trailer will lower when the dolly is pushed under it

visually check that they are level height wise

visually check that the rear trailer is lower than the fifth wheel so that the trailer raises slightly when the dolly is pushed under it

22 / 40

You should activate hazard lights within approximately how many feet before railroad crossing?

400 feet

200 feet

250 feet

300 feet

23 / 40

Why is the proper adjustment and use of all mirrors so vital to the safe operation of the school bus?

In order to see if small vehicles are driving in the bus blind spots.

In order to clear up blind spots around the bus.

In order to observe the danger zones around the bus and look for the students, traffic, and other objects in this area.

In order to observe the danger zones around the bus.

24 / 40

When driving normally, some drivers use the hand valve before applying the brake pedal to prevent jack knifing. Select the most appropriate response to this statement.

it should not be done

it will result in less skidding than when just using the brake pedal alone

should be used with caution and only if you are aware of the dangers

it is the best possible way to brake and maintain the truck in a straight path

25 / 40

Most states require school bus drivers to take a physical examination:

Every 3 years

Annually

Every 2 years

Twice per year

26 / 40

On a bus, you may sometimes haul small-arms ammunition, emergency shipments of drugs, or hospital supplies. The total weight of all such hazardous materials must not be greater than:

100 pounds

300 pounds

500 pounds

250 pounds

27 / 40

Why should you test the tractor protection valve?

to avoid the emergency brakes kicking on due to loss of air

all answers listed

to avoid loss of air from the air hose

to avoid loss of air from the trailer brakes

28 / 40

A driver of a tank vehicle should take curves, off ramps, and on ramps at a speed lower than the posted speed limit.

True but only in rainy conditions

True

True but only in ideal conditions

False

29 / 40

What are the liquid tight separations between compartments inside tanks called?

Waffles

Bulkheads

None of the answers listed

Layers

30 / 40

Select the statement of what you should not do if you are required to drive through flowing water or deep puddles.

quickly turn the steering wheel side to side

shift into a lower gear

increase engine rpm

drive at a high speed

31 / 40

When is it best to wear your seat belt?

Only if your bus holds more than 27 people.

Only when you will be driving over 35 mph.

Only if required by company policy.

Always.

32 / 40

This item does not need to be checked during the cab check.

The windshield wipers and fluid levels

The air conditioning

The horn

The defroster/heater

33 / 40

If your bus has an emergency exit door, it must:

Not have any signs, stickers, or markings anywhere near it.

Be closed when operating the bus.

Have a red electric door light turned on at all times.

All of these answers are correct.

34 / 40

What will probably happen if the converter dolly is still under the second trailer and the pintle hook is unhooked?

the engine brakes will unlock

the dolly tow bar could fly up

nothing will happen

the air lines will explode

35 / 40

Drivers who transport route controlled radioactive materials must carry a dated certificate of radioactive materials training. This training must have ocurred within the last:

3 years

2 years

1 years

4 years

36 / 40

The trailer height is correct for connecting a converter dolly to a second or third trailer when:

the center of the kingpin is past the locking jaw

the trailer will rise slightly when the converter dolly is backed underneath it

the kingpin is over the fifth wheel

all answers listed

37 / 40

These tires should have a minimum tread depth of 4/32 inches.

Steering axle tires

Donut tires

Non-steering axle tires

Drive axle tires

38 / 40

The bus driver must accept responsibility for supervising and controlling students while on the bus route. Who is the person in charge?

Parents of the students on the bus.

Bus driver.

Students on the bus.

The school district superintendent.

39 / 40

Which of the following is the most important reason for doing a pre-trip inspection?

because other drivers do it

to make sure nothing has been stolen from the vehicle

safety for yourself and other road users

to make sure the vehicle will make your destination

40 / 40

Select the factor that has no effect on how much liquid you can carry:

The liquid's weight.

How much the liquid will expand in transport.

The legal amount of weight you can carry of any particular liquid.

The density of the liquid.

Your score is

The average score is 60%

5/5 - (2 votes)

CDL Category Practice Tests

CDL Practice Test

How To Get A california Commercial Drivers License

Residents of California may apply for their CDL at the age of 18 years old. These residents may only drive within the California state borders and are not eligible for driving hazmat vehicles. Residents over the age of 21 are eligible for interstate commerce and may receive their Hazmat Certification. All residents must undergo a medical examination by an approved Medical Examiner. The examiner will provide the individual with a Medical Examiner’s Certificate that will show their physical ability to be eligible to operate a commercial vehicle.

Any drivers who falls into the following categories are disqualified from receiving their commercial driver’s license.

Convicted of driving a commercial vehicle impaired in the past two years.
Having multiple driver’s license.
Having a revoked, denied, canceled, or suspended driver’s license.
Being disqualified from obtaining CDL driving privileges in another state.

Applicants for a California CDL must complete a vision test at the time of their application, along with one or more knowledge tests and a practical skills test.

Endorsements
S – School Bus
N – Tank
P – Passenger
H – Hazardous Materials
X – Hazmat and Tank Combination
P – Passenger Vehicle

Hit the Open Road

California CDL License Test Tips

Knowledge tests are required to be passed by all California residents seeking a commercial driver’s license. Class A applicants are required to complete a 70 question assessment regarding both general commercial driving knowledge and combination driving. Class B and C applicants are required to pass a 50 question assessment about general commercial driving knowledge. Those seeking endorsements or the removal of the Air Brake restriction will have to take additional knowledge tests. Each endorsement has a 20 to 30 question assessment based on the topic of the endorsement. All knowledge tests must be passed for the resident to receive their CDL. A passing score is receiving an 80 percent or higher on the assessment. Each applicant is responsible for showcasing their ability to operate a commercial vehicle as part of the CDL skills test. There are three main parts to this test which include the on-road test, pre-trip inspection, and basic control skills test. Applicants must pass all three parts to receive their commercial driver’s license.

Additional Information

Information on the California Department of Motor Vehicles

The State of California Department of Motor Vehicles regulates the certifying and testing of commercial drivers in the California. To get more information contact them via:

Website: https://www.dmv.ca.gov/portal/dmv/detail/commercial/commercial

Phone: 800.777.0133

Additional California CDL Helpful Links

Please use the links below to access more valuable California CDL testing resources and to learn more about practice driving tests for the state of California.

california CDL Practice Test