CDL Combination Vehicles Practice Test Results

Question 1
89% answer correctly
When is the proper time to use the trailer handbrake to straighten out a trailer that`s jackknifing?
When you start to recover from the jackknife
As soon as you start to jackknife
Never
In the middle of the jackknife
Question 2
90% answer correctly
Which of the following statements about combination vehicles is true?
All of these are true
Driving combination vehicles is no different than driving single commercial vehicles
They`re heavier, longer and require more driving skill than single commercial vehicles
Single commercial vehicles are heavier, longer and require more driving skill than combination vehicles
Question 3
53% answer correctly
When hooking up a tractor to a trailer, the trailer is at the proper height when:
The trailer dolly wheels are just barely off the ground when fully extended
The coupling surface of the trailer is just below the middle of the tractor fifth wheel
The kingpin is just below the middle of the tractor fifth wheel
The coupling surface of the trailer is just above the middle of the tractor fifth wheel