FREE CDL Combination Vehicles Practice Test Online | Nebraska 2024 Page 4 of 4
Train for FREE online with our Nebraska CDL combination vehicle test. 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 NE combination license in 2021, 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 for issuing a combination license may vary from state to state.
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19 . After coupling, there should be ____ between the upper and lower fifth wheel.
Three inches of space
Before a trip, be sure to inspect all couplings. There should be no space between the upper and lower fifth wheel.
20 . If unsure if a trailer has an Anti-Lock Braking System (ABS), you can:
If you do not know whether or not a trailer is equipped with ABS, look under the vehicle for the electronic control unit and wheel speed sensor wires coming from the back of the brakes.
21 . When coupling:
Incorrect coupling and uncoupling of combination vehicles can have extremely dangerous consequences.
22 . What happens when the wheels of a trailer lock up?
The trailer will stop.
A trailer tends to swing around, potentially resulting in a trailer jackknife, if its wheels lock up.
23 . An air supply control lever should be in its "normal" position when you are:
Using your spring brakes.
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.
24 . To lower the risk of a rollover, you should:
Stack the cargo as high as possible.
