CDL Combination Vehicles Practice Test Results

Question 1
49% answer correctly
Rearward amplification array(the "crack-the-whip" effect) is greater in combinations where there are __________ and __________ trailers.
Fewer, longer
Fewer, shorter
More, longer
More, shorter
Question 2
92% answer correctly
On a combination vehicle what color is the emergency air line?
White
Black
Yellow
Red
Question 3
53% answer correctly
When hooking up a tractor to a trailer, the trailer is at the proper height when:
The coupling surface of the trailer is just above the middle of the tractor fifth wheel
The coupling surface of the trailer is just below the middle of the tractor fifth wheel
The trailer dolly wheels are just barely off the ground when fully extended
The kingpin is just below the middle of the tractor fifth wheel