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Iowa CDL DMV Knowledge Test Class A 1

Take 6 practice tests for CDL is the best way to prepare for your Iowa DMV exam is by taking our free practice tests. The following question are from real Iowa DMV practice test. More than 95% people pass a DMV exam when practice at DMV Practice Test.

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1. When loading cargo, it is important to:
Stack items as high as possible.
Know the weight capacity rating of the suspension system.
Place light items underneath heavier items.

It is a driver's responsibility to make sure their vehicle is not overloaded. They must be aware of legal weight limits and the maximum weight that their vehicle is rated to carry, including the weight capacity rating of the suspension system.

2. Most heavy vehicles use the ____ method when changing gears.
Double clutching
Double shifting
Triple clutching

Most heavy vehicles with unsynchronized manual transmissions require double clutching to change gears.

3. A truck should be parked:
So that it must be backed up to leave the space.
So that it can be pulled forward to leave the space.
On the grass.

Because you can't see everything behind you, backing is always dangerous and should be avoided whenever possible. Choose parking spaces from which you can pull forward when you leave.

4. If you’re not sure what to do to extinguish a fire in your vehicle, you should:
Use water.
Stay inside the vehicle.
Wait for the firefighters.

If you are not sure which kind of extinguisher should be used on a fire in your vehicle, particularly a hazardous materials fire, you should wait for the firefighters to arrive and allow them to extinguish it.

5. The leakage rate for a single vehicle with air brakes should be no more than ____ in one minute during a static leakage test.
1 psi
2 psi
3 psi

When performing a static leakage test on a single vehicle with air brakes, the leakage rate should be no more than 2 psi in a minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

6. Causing a fatality through negligent operation of a CMV will result in the loss of your CDL for a minimum of:
One month.
Six months.
One year.
Three weeks.

A first conviction of causing a fatality through negligent operation of a CMV will result in the loss of your CDL for at least one year.

7. 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.

8. Air tank drains should:
Not be used by the driver.
Only be used when it is wet outside.
Be used to drain the tanks completely.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

9. ____ are the most likely to be affected by strong winds.
Light vehicles
Heavy vehicles
Vehicles with open windows

Strong winds can make it difficult for a driver to maintain control of their vehicle. Usually, this is especially true for drivers of lighter CMVs.

10. When should you slow for a curve?
Before entering the curve
While in the curve
After the curve

You should always slow to a safe speed before entering a curve. Slowing while within the curve could cause a skid.

11. Of the following, which is not a recommended way to spot potential signs of trouble?
Watching the gauges
Using your senses
Checking critical items only at the beginning and end of a trip

During a trip, you should regularly make checks to ensure that your vehicle is operating properly. Check the instrument panel and gauges; look at your mirrors; and examine the tires, cargo, and lights. Use all of your senses and be alert for anything that could be an early indication of trouble.

12. Dry bulk tanks:
Cannot be driven on interstates.
Take special care to be driven.
Are usually not allowed to cross railroad tracks.

Dry bulk tanks require special care to be driven, both because they have high centers of gravity and because the weight of the load can shift in transit.

13. 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.

14. When using a mirror, you should:
Look quickly at the mirror.
Stare at the mirror for a long time.
Use only the driver’s side mirror.

When making mirror checks, you should look at the mirrors fairly quickly. If you spend too much time looking in a mirror, you may travel a substantial distance down the road without seeing what is coming up ahead.

15. Texting while driving should:
Only be done on straightaways.
Only be done in curves.
Not be done.

Texting while driving is a dangerous distraction and is prohibited at all times when operating a CMV.

16. Traction is important in:
Safe braking.
Properly using turn signals.
Operating the horn.

You will not be able to brake or steer your vehicle without adequate traction. Ensure that your tires are in proper working condition before beginning a trip.

17. If your brakes fail on a downgrade, your best hope to stop is to:
Use an escape ramp.
Use the shoulder.
Drift to a stop.

If your brakes fail on a downgrade, you will have to look outside your vehicle for a way to stop. Using an escape ramp is the safest way to stop your vehicle.

18. If approaching a vehicle with a distracted driver, you should:
Quickly pass the vehicle.
Maintain a safe distance from the vehicle.
Closely follow the vehicle.

If you see a distracted driver, give them plenty of space and maintain a safe following distance.

19. If there is a fire in your vehicle and you are not sure how to extinguish it, you should:
Use a fire extinguisher.
Try douse the flames with water.
Move away from the flames and wait for the firefighters.

If you are not sure which method to use when putting out a fire, do not attempt to extinguish the fire on your own. Instead, wait for firefighters to arrive and let them handle it. This is especially true if you are experiencing a hazardous materials fire.

20. Within 10 minutes of stopping on the side of the road, you must:
Place emergency warning devices.
Alert local law enforcement.
Call a mechanic.

If you must stop on the side of the road, you must place the appropriate emergency warning devices within 10 minutes of stopping.

21. If confronted by an aggressive driver, you should:
Keep your vehicle in front of them.
Make eye contact with them
Ignore their gestures.

If confronted by an aggressive driver, don't let yourself be provoked by their actions or angry gestures. Do not risk provoking the other driver by making eye contact. Get out of their way if you can do so safely.

22. When completing an offset back/left parking maneuver, a driver should:
Pull straight forward, then back to the left.
Drive straight back, then pull forward to the left.
Pull straight forward, then drive straight back.

If you are asked to complete an offset back/left parking maneuver, you should first pull straight forward, then back up to the left. Your vehicle must be parked completely within the boundaries of the parking space.

23. In a vehicle with dual parking control valves, a separate air tank can be used:
To make the air brakes work more effectively.
To temporarily release the spring brakes.
To charge the brakes on the rear trailer.

In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

24. When driving in fog, you should:
Slow down.
Speed up.
Drive on the shoulder.

It is best not to avoid driving in fog. However, if you must drive under foggy conditions, be sure to decrease your speed.

25. When transporting cargo, drivers must check the securement of the cargo every:
10 miles.
150 miles.
500 miles.

The securement of cargo must be checked before beginning a trip, within the first 50 miles of a trip, and then again every three hours or 150 miles thereafter.

26. To prevent becoming an aggressive driver you should:
Increase your speed.
Make gestures at other drivers.
Give other drivers the benefit of the doubt.

To avoid engaging in aggressive driving behavior, it is helpful to give other drivers the benefit of the doubt. Assume that they have valid reasons for what they are doing and don't take their actions personally.

27. 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.

28. When driving:
It is best to hide your intentions from others.
You should only use turn signals if there are vehicles near you.
You should not use turn signals in construction zones.
You should always use turn signals to warn others about your intentions.

It is important to communicate your intentions to others on the road. Make sure to signal before turning or changing lanes, even if no other vehicles are nearby.

29. Failing to drain air tanks could result in:
Water accumulations freezing and causing brake failure.
Squishy brakes.
Too much air collecting in the tanks.

In an air brake system, the air tanks must be periodically drained to remove accumulations of water and compressor oil. If water is not removed, it could freeze in cold weather and cause brake failure.

30. If a load is 10 feet long, it must be secured by a minimum of ____ tie-downs.

On flatbed trailers and trailers without sides, cargo must be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.

31. When turning, you should:
Signal before the turn.
Turn off your turn signal just before starting the turn.
Signal only if vehicles are in front of you.

Be sure to activate the appropriate turn signal well in advance of a turn or lane change. Signal continuously throughout the turn and make sure to cancel the signal after the turn is completed, if your vehicle doesn't have self-canceling signals.

32. Radial and bias-ply tires:
Should be used together.
Should be used together on the front of a vehicle.
Should not be used together.

Radial and bias-ply tires should not be used together. All wheels on a vehicle should be the same style and equally-sized.

33. When approaching a railroad crossing, you should:
Rely on warning signals to indicate if a train is approaching.
Rely on the actions of other motorists to indicate if a train is approaching.
Not rely solely on warning signals to indicate if a train is approaching.

You should not rely solely upon the presence of warning signals, gates, or flaggers to alert you to the approach of a train. Be especially alert to approaching trains at crossings that are not controlled by gates or signals. At any railroad crossing, you should operate under the assumption that a train is coming.

34. If the safety relief valve in the air brake system releases air:
The compressor needs more air.
The air pressure has become too high.
The brakes are fully operational.

An air brake system has a safety relief valve, which releases air from the tanks if the pressure gets too high. If the valve must operate, something in the system is wrong and should be addressed by a mechanic.

35. During the vehicle inspection test, you will be asked to:
Change a tire.
Explain to the examiner what you are inspecting and why.
Estimate the weight of a load on a trailer.

During the vehicle inspection test, you will be asked to do a complete inspection of your vehicle. You will need to explain what you are inspecting and why.

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