CDL Combination Vehicle Practice Test
Questions and Answers
1.A tractor with a(n) trailer requires the shortest amount of
stopping distance.
1. empty
2. fully loaded
3. lightly loaded
Answer fully loaded
2.The air leakage rate for a combination vehicle (engine off, brakes on)
should not be more than psi per minute.
1. 4
2. 6
3. 2
Answer 4
3. If you do not do the final air brake check for air leaks and fix them before
driving,
1. you could lose your brakes while driving
2. your fuel usage will increase
3. tire pressure will drop
Answer you could lose your brakes while driving
1/
12
, 4.Which part of the kingpin should the locking jaws close around?
Answer The shank
5.Glad hands are used to connect the ....
1. kingpin from the trailer to the locking jaws of the fifth wheel
2. electrical lines from the tractor to the trailer
3. service and emergency air lines from the truck or tractor to the trailer
Answer ser- vice and emergency air lines from the truck or tractor to
the trailer
6.Trucks roll over more easily when fully loaded and are
1. ten times more likely to roll over in a crash than empty rigs
2. five times more likely to roll over in a crash than empty rigs
3. two times more likely to roll over in a crash than empty rigs
Answer ten times more likely to roll over in a crash than empty rigs
7.In general, the higher your trucks center of gravity, the ...
1. easier it is to turn over
2. more stable it is when turning
3. easier it is to turn around corners
Answer easier it is to turn over
8.You are driving a combination vehicle when the trailer breaks away,
pulling apart both air lines. You would expect the trailer brakes to come on
and ...
2/
12
Questions and Answers
1.A tractor with a(n) trailer requires the shortest amount of
stopping distance.
1. empty
2. fully loaded
3. lightly loaded
Answer fully loaded
2.The air leakage rate for a combination vehicle (engine off, brakes on)
should not be more than psi per minute.
1. 4
2. 6
3. 2
Answer 4
3. If you do not do the final air brake check for air leaks and fix them before
driving,
1. you could lose your brakes while driving
2. your fuel usage will increase
3. tire pressure will drop
Answer you could lose your brakes while driving
1/
12
, 4.Which part of the kingpin should the locking jaws close around?
Answer The shank
5.Glad hands are used to connect the ....
1. kingpin from the trailer to the locking jaws of the fifth wheel
2. electrical lines from the tractor to the trailer
3. service and emergency air lines from the truck or tractor to the trailer
Answer ser- vice and emergency air lines from the truck or tractor to
the trailer
6.Trucks roll over more easily when fully loaded and are
1. ten times more likely to roll over in a crash than empty rigs
2. five times more likely to roll over in a crash than empty rigs
3. two times more likely to roll over in a crash than empty rigs
Answer ten times more likely to roll over in a crash than empty rigs
7.In general, the higher your trucks center of gravity, the ...
1. easier it is to turn over
2. more stable it is when turning
3. easier it is to turn around corners
Answer easier it is to turn over
8.You are driving a combination vehicle when the trailer breaks away,
pulling apart both air lines. You would expect the trailer brakes to come on
and ...
2/
12
