CDL Combination Vehicles Practice Test Results

Question 1
81% answer correctly
What`s the purpose of the trailer air supply control?
Supplies air to the cab
Prevents trailers from becoming decoupled
Engages the trailer air brakes
Supplies air to the trailer
Question 2
60% answer correctly
After pushing in the trailer supply valve you should not move the tractor until:
The entire air system is above 60 psi and the warning buzzer has stopped
The warning buzzer has stopped
The entire air system is above 120 psi and the warning buzzer has stopped
The entire air system is above 120 psi
Question 3
90% answer correctly
How would a driver supply air to trailer air tanks?
Pull out the trailer air supply valve
Activate the air generator
Push in the trailer air supply valve
Activate the service line