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Connecticut CDL DMV Combination 1

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

Number of Test
6
Number of Question
20
Passing score
16
13%
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  • 0Incorrect
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1. When you are pulling a trailer, the air supply control lever should be in its ____ position.
Emergency
Supply
Normal

Tractor protection controls in older vehicles may be operated by levers instead of knobs. If an air supply control is set in its "normal" position, it is properly set for you to pull a trailer.

2. A shut-off valve:
Is located on the front of a trailer.
Is located on the instrument panel.
Prevents air from escaping an air brake system.
Should always be open.

Shut-off valves are used in air supply lines to control the passage of air from one trailer to another. The rear shut-off valve should always be closed to prevent air from leaving the braking system.

3. What is a bobtail tractor?
A tractor without a trailer
A tractor attached to two trailers
A tractor with a tank

Tractors without semi-trailers are referred to as bobtail tractors. Operating a bobtail tractor requires drivers to exercise caution.

4. When glad hands are coupled, the seals should be pressed together at an angle of:
30 degrees.
45 degrees.
60 degrees.
90 degrees.

When coupling, be sure to couple the proper glad hands. When glad hands are connected, the seals should be pressed together at a 90-degree angle.

5. A tractor protection valve is:
A device that keeps air in the tractor or truck brake system, should the trailer break away or develop a bad leak.
A device that prevents theft.
A device that controls fuel levels.
A device that allows the battery to recharge efficiently.

On combination vehicles with air brakes, the tractor protection valve keeps air in the tractor or truck brake system, should the trailer develop a bad leak or break away from the tractor.

6. The easiest way to recognize that your trailer has begun to skid is to:
Ask another driver.
Use your mirrors to determine if the trailer has left the lane.
Release the brake pedal and then push it down again.
Watch the jackknife warning light on the control panel.

The easiest way to spot a trailer skid is to use your mirrors. Any time you brake hard, check your mirrors to ensure that your trailer is still in its proper position.

7. What happens when the wheels of a trailer lock up?
The trailer will often continue to move in a straight line.
The trailer may disengage.
The trailer may swing around.
Steering will become easier.

A trailer may swing out and strike other vehicles if its wheels lock up. This is especially likely with lightly-loaded trailers.

8. If a trailer begins to skid, the driver should:
Lock the brakes.
Release the brakes.
Steer in the opposite direction.
Accelerate.

If your trailer starts to skid while you are braking, you should release the brakes and allow them to begin to regain traction. Once its wheels have regained their grip on the road, the trailer will begin to straighten out and follow the tractor.

9. When braking while pulling a trailer equipped with anti-lock brakes, you should:
Pump the brakes.
Use extra braking force to ensure the brakes kick in.
Brake as you would without anti-lock brakes.

When driving a tractor-trailer combination that is equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if the vehicle was not equipped with ABS.

10. What does an Anti-Lock Braking System (ABS) do?
It allows a vehicle's wheels to lock up.
It prevents a vehicle's wheels from locking up.
It makes turning a vehicle easier.

An Anti-Lock Braking System (ABS) helps prevent wheel lockup during hard braking. If ABS detects impending lockup, it reduces braking pressure to a safe level.

11. Before a drive, ensure that air flows to all trailers by:
Opening the rear shut-off valves and listening for escaping air.
Closing the rear shut-off valves and listening for escaping air.
Disconnecting air supply lines and listening for escaping air.
Rolling each trailer down a hill and testing the brakes.

Before a trip, ensure that air in the air brake system reaches all trailers. Do this by waiting for air pressure to build, then sending air to both the emergency and service lines and opening the shut-off valves on the rear of the last trailer. If air escapes from the shut-off valves in the rear of the combination, the air is being supplied to the entire vehicle.

12. Before a trip, you can make sure air flows to all trailers by:
Checking for moving air inside of each trailer.
Listening for air at the rear shut-off valve.
Feeling for air at the front shut-off valve.

Before a trip, ensure that air in the air brake system reaches all trailers. Do this by waiting for air pressure to build, then sending air to both the emergency and service lines and opening the shut-off valves on the rear of the last trailer. If air escapes from the shut-off valves in the rear of the combination, the air is being supplied to the entire vehicle.

13. During a trip, which shut-off valves should be open?
All shut-off valves should be open.
The rear shut-off valves should be open.
All shut-off valves should be in the open position, except the rear shut-off valves.
No shut-off valves should be open.

When starting a trip, be sure that all shut-off valves are in the open position, except for the last valves on the rear trailer. It is important that air reaches the brakes on all trailers and that the air is not able to escape from the back of the vehicle.

14. A combination vehicle has:
One air line.
Two air lines.
Three air lines.
Four air lines.

Combination vehicles have two air lines: a service line and an emergency line.

15. If colors are being used to distinguish glad hands, which color is used for service lines?
Orange
Yellow
Green
Blue

When trailer air lines are color-coded, the service lines are generally blue and the emergency lines are generally red.

16. When traveling more slowly than 40 mph, maintain at least ____ of following distance per every 10 feet of your vehicle.
One second
Two seconds
Three seconds
Four seconds

At speeds below 40 mph, you should allow at least one second of following distance for every 10 feet of your vehicle. Follow the same formula when traveling at faster speeds, then add one additional second to your following distance. Remember that larger vehicles require more space to stop than smaller vehicles.

17. The "crack-the-whip" effect can:
Turn over a trailer.
Be more effective than braking.
Make a truck move faster.

Trailers can overturn as a result of the "crack-the-whip" effect. The last trailer in a combination is the most prone to tip over due to this effect. Drivers should be aware of the rearward amplification of their specific vehicles and drive accordingly.

18. Having ABS on only one axle:
Does not change braking in any way.
Is not possible.
Will allow the driver additional control over their vehicle when braking.
Will cause extra strain on the other axles.

Having an Anti-Lock Braking System (ABS) on only the trailer, or even on just one axle, will still provide a driver with additional control over the trailer when braking.

19. Fully-loaded rigs:
Are less likely to roll over than empty rigs.
Are more likely to roll over than empty rigs.
Are just as likely to roll over as empty rigs.
Should not be driven.

Because the weight of cargo gives them a higher center of gravity, fully-loaded rigs are 10 times more likely to roll over in a crash than empty rigs.

20. When driving a bobtail tractor, you should be aware that:
Bobtails stop very easily.
Bobtails cannot drive as fast as tractors with semitrailers.
Bobtails are more difficult to stop than tractors with semitrailers.
Bobtails are illegal in most states.

Bobtail tractors are tractors that are not attached to any semitrailers. When operating a bobtail, you should be aware that stopping can be difficult and that it will take a longer distance to bring the bobtail to a complete stop than it would a tractor attached to a loaded semitrailer.

Your Progress
  • 0Incorrect (4 allowed to pass)
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