A retarder is a device that helps to slow a vehicle, reducing the need for a driver to use the brakes. However, these devices can be noisy and are not permitted everywhere.

They may not be permitted everywhere.

They can help to slow a vehicle.

The air storage tanks in an air brake system store compressed air to be used for braking. They hold enough air for the brakes to still be used several times if the compressor stops working.

Hold enough air for the brakes to be used several times if the compressor stops working.

Hold only enough air for one braking cycle.

Hold enough air for the brakes to be used several times if the compressor stops working.

Do not hold air unless there is an emergency.

In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.

When tank pressure falls below 60 psi.

When tank pressure falls below 120 psi.

When tank pressure falls below 60 psi.

When tank pressure falls below 10 psi.

When tank pressure falls below 5 psi.

The emergency air line controls the emergency brakes on a combination vehicle. A loss of air pressure in the emergency line will cause the emergency trailer brakes to activate.

The emergency brakes will activate.

The Anti-Lock Braking System will activate.

The service air line will activate.

The emergency brakes will activate.

Always observe posted speed limits for work zones. Slow down if road or weather conditions are adverse, and slow down even more if workers are on or near the road.

Steer with one hand and keep the other hand free.

If your vehicle begins to hydroplane, do not apply the brakes. Instead, slow down by releasing the accelerator and pushing in the clutch. This will help you to regain traction.

Turn the steering wheel as hard as possible.

Double Triple Test | Iowa 2024 #2

Train for FREE with our Iowa CDL double triple practice test online. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a IA CDL double triple license in 2024, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

Double Triple Test | Iowa 2024 #2

1 . What is a drawback of retarders?

2 . The air storage tanks:

3 . When should mirrors be adjusted?

4 . A low air pressure warning signal should activate:

5 . If the emergency air line loses pressure:

6 . When traveling through a work zone, you should:

7 . If your vehicle is hydroplaning, you should:

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