CDL DOUBLES TRIPLES PRACTICE TEST DISTRICT OF COLUMBIA

11. Exhaust system parts should NOT:
rub against tires.
be loose.
rub against fuel system parts.
All of the above.
12. Because of the "crack-the-whip" effect, doubles and triples:
are more likely to run out of gas than other combination vehicles.
are more likely to turn over than other combination vehicles.
are much slower than other combination vehicles.
can go much faster than other combination vehicles.
13. In vehicles with air brakes, the air compressor governor:
controls how much air the air compressor will pump into the air storage tanks.
controls when the air compressor will pump air into the air storage tanks.
controls when the air storage tanks will pump air into the air compressor.
None of the above.
14. Emergency brakes are:
not required on buses.
required on all vehicles.
not required on commercial vehicles with air brakes.
not required on doubles.
15. If your vehicle has air brakes, to check that air flows to all trailers:
watch each trailer’s air gauge for a drop of 25 psi.
go to the rear of the second trailer and open the emergency line shut-off.
check that the fifth wheel is not so far forward that the tractor frame will hit the landing gear.
pull gently on the trailer with the tractor.
16. If the air compressor is belt-driven, you should check the air compressor drive belt before each trip. The belt should be:
tight.
loose.
cracked.
worn.
17. Why should you cover your cargo?
To protect people from spilled cargo.
Because spill protection is a safety requirement in many states.
To protect the cargo from weather.
All of the above.
18. Which of the following is not a type of retarder?
Exhaust
Electric
Hydraulic
Pressure
19. Off-tracking is:
when a vehicle towing a trailer skids, and the trailer pushes the towing vehicle from behind until it spins the vehicle around.
when a vehicle makes a turn and the rear wheels of the trailer end up driving in a different path than the tractor and the front wheels of the trailer.
when the tires lose their contact with the road and have little or no traction.
None of the above.
20. You are driving a heavy vehicle with a manual transmission, and you have to stop on the shoulder while driving on an uphill grade. When putting your vehicle back in motion up the grade, you should:
partly engage the clutch before you take your right foot off the brake.
use the parking brake to hold the vehicle until the clutch engages.
shift down to a speed that you can control without using the brakes.
keep the clutch slipping while slowly accelerating.
GRADE ME
NOT SURE YOU WILL PASS? GET CDL PREMIUM NOW! - Learn More