Practice question

The trailer hand valve should be used:

  1. Regularly to activate the trailer brakes in all driving conditions.
  2. Only to test the trailer brakes.
  3. Only in inclement weather when the trailer may skid.
  4. Only if the trailer is carrying a load.

Answer: B — Only to test the trailer brakes.

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: North Dakota CDL Combination Test 1 →