FREE Missouri Combination Practice Test (2023)

1. In combination vehicles with air brakes, the trailer air supply control should pop out when the air pressure falls within the range of:

2. A trailer jackknife is more likely to happen when the trailer is:

3. Inspecting the fifth-wheel does NOT include:

checking for missing or damaged parts.
backing until the fifth-wheel just touches the trailer.
checking that there are no cracks in the frame.

4. Transporting hanging meat requires special attention. Why?

Because hanging meat can be an unstable load with a high center of gravity.
Because you have to drive fast to get it delivered fresh.
Because refrigerated trucks have less traction.

5. Overloading can have negative effects on:

6. When backing a trailer on a curved path you should back towards:

either side.
the driver's side.
neither side (back up straight).

7. The use of brakes on a steep downgrade is:

a supplement to the braking effect of the engine.
the main braking factor.
much more effective than the engine braking effect.

8. On a tractor-trailer equipped with a trailer brake hand valve, the hand valve can be used to:

9. If the safety relief valve in the air brake system releases air:

the valve is fully operational.
this will supply more power to the brakes.
something is wrong.

10. When driving at night you should:

use your high beams when it is safe and legal to do so.
always use low beams.
All of the above.

CDL COMBINATION PRACTICE TEST MISSOURI