Combination
All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the State of Delaware Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice questions, and applicants will need to correctly answer a minimum of 16 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.
Number of Question
Passing Score
15. A trailer will be most likely to swing around when:
Explanation
An empty trailer will require a longer stopping distance than a loaded trailer. Additionally, a trailer is most likely to swing out and strike other vehicles when it is lightly loaded or empty.
16. Keeping cargo low can:
Explanation
Rollovers can happen when a combination vehicle is turned too quickly. To help prevent the risk of rollover, it is important to keep the vehicle's center of gravity low by loading cargo as close to the ground as possible.
17. When a combination vehicle goes around a corner:
Explanation
When a vehicle goes around a corner, the rear wheels follow a different path than the front wheels. This is called off-tracking. This effect is especially pronounced on vehicles with trailers.
18. When glad hands are coupled, the seals should be pressed together at an angle of:
Explanation
When coupling, be sure to couple the proper glad hands. When glad hands are connected, the seals should be pressed together at a 90-degree angle.
19. If the emergency air line loses pressure:
Explanation
The emergency air line controls the emergency brakes on a combination vehicle. A loss of air pressure in the emergency line will cause the emergency trailer brakes to activate.
20. When traveling more slowly than 40 mph, maintain at least ____ of following distance per every 10 feet of your vehicle.
Explanation
