AZ License Mock Exam:With A+ Graded Solution 2026/2027

AZ License Mock Exam:With A+ Graded Solution
2026/2027
1. What is the main purpose of the air compressor governor?

 A) To control the engine speed.

 B) To control when the compressor pumps air into the storage tanks.

 C) To regulate the pressure in the tires.

 D) To protect the engine from overheating.

 Correct Answer: B. The governor monitors tank pressure and tells the compressor
when to "cut-in" (start pumping) and "cut-out" (stop pumping).

2. At what pressure should the "cut-out" typically occur?

 A) 60–80 psi.

 B) 80–100 psi.

 C) 120–135 psi.

 D) 150–175 psi.

 Correct Answer: C. Most modern systems are set to stop pumping between 120 and
135 psi to prevent over-pressurization.

3. What is the maximum leakage rate allowed for a combination vehicle (Tractor-Trailer) with
the brakes applied?

 A) 2 psi per minute.

 B) 3 psi per minute.

 C) 4 psi per minute.

 D) 6 psi per minute.

 Correct Answer: C. If the pressure drops more than 4 psi in 60 seconds with the
service brakes held down, the vehicle has a major air leak.

4. Why must you drain the water from the air tanks daily?

 A) To prevent the air from becoming too heavy.

 B) To prevent oil and water from freezing or causing brake failure.

 C) To increase the air pressure.

 D) To clean the inside of the tires.

 Correct Answer: B. Moisture in the lines can freeze in winter, blocking air flow, and
oil can damage the rubber seals in the brake chambers.

5. What is the function of the "Tractor Protection Valve"?

 A) To keep the tractor clean.

,  B) To keep air in the tractor tanks if the trailer breaks away or leaks.

 C) To automatically turn on the trailer lights.

 D) To increase the fuel efficiency.

 Correct Answer: B. It is a safety valve that closes if it senses a major air loss in the
trailer lines, ensuring the tractor still has brakes.

6. What is the "Kingpin"?

 A) The driver of the lead truck in a convoy.

 B) The main pin under the front of the trailer that locks into the fifth wheel.

 C) The bolt that holds the steering wheel.

 D) The tool used to check tire pressure.

 Correct Answer: B. The kingpin is the primary structural connection between the
tractor and trailer.

7. How do you perform a "Tug Test"?

 A) Pull the trailer hand valve while driving 50 km/h.

 B) Gently try to pull forward with the trailer brakes locked to ensure the fifth wheel is
secure.

 C) Pull on the air lines to see if they are tight.

 D) Pull the steering wheel to the left and right.

 Correct Answer: B. This confirms that the fifth wheel jaws have successfully locked
around the kingpin.

8. What is the minimum tread depth for a steering (front) tire?

 A) 1.5 mm.

 B) 2.0 mm.

 C) 3.0 mm.

 D) 5.0 mm.

 Correct Answer: C. Front tires require more tread for steering grip and safety; all
other tires require 1.5 mm.

9. What does the "Z" endorsement on your license mean?

 A) You can drive in zero-visibility conditions.

 B) You are qualified to operate a vehicle equipped with air brakes.

 C) You can drive a vehicle with more than 4 axles.

 D) You are a trainee driver.

,  Correct Answer: B. Any driver operating a vehicle with an air brake system must have
this endorsement.

10. When should you use the trailer hand valve (Johnson Bar)?

 A) To park the vehicle on a hill.

 B) To test the trailer brakes or prevent rolling back during a start.

 C) To stop the truck in an emergency.

 D) To slow down while descending a long grade.

 Correct Answer: B. It should never be used for parking or general braking as it can
cause a jackknife or overheat the trailer brakes.

11. What is "Brake Fade"?

 A) When the brake lights stop working.

 B) Loss of stopping power due to heat causing the brake drums to expand.

 C) When the air compressor cannot keep up.

 D) When the driver forgets to apply the brakes.

 Correct Answer: B. Excessive heat causes the drum to expand away from the shoes,
requiring more force to stop.

12. In Ontario, a daily inspection report (Circle Check) is valid for:

 A) 12 hours.

 B) 24 hours.

 C) 48 hours.

 D) 7 days.

 Correct Answer: B. You must perform a new inspection and complete a new report
every 24-hour period.

13. What color is the Trailer Supply (Emergency) line?

 A) Blue.

 B) Green.

 C) Red.

 D) Yellow.

 Correct Answer: C. Red is the standard color for the emergency air supply line.

14. At what air pressure should the low-air warning device (buzzer/light) activate?

 A) 100 psi.

 B) 80 psi.