Commercial Driver’s License (CDL) Exams –
Verified Questions, Correct Answers, and
Detailed Explanations for Students||Already
Graded A+
1. What is the minimum age requirement to obtain a CDL in the United
States?
A. 16
B. 18
C. 21
D. 25
Answer: B. 18
Rationale: To drive intrastate commercial vehicles, you must be at least 18. For
interstate driving, the minimum age is 21.
2. Which class of CDL is required to operate a combination vehicle with a
GVWR over 26,001 lbs?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A. Class A
Rationale: Class A CDLs cover combination vehicles where the combined GVWR
exceeds 26,001 lbs.
3. When backing a truck, the safest method is:
A. Rely solely on mirrors
B. Use a spotter if possible
C. Turn around and look through the rear window
D. Speed up to finish quickly
Answer: B. Use a spotter if possible
Rationale: A spotter provides guidance and reduces blind spot risks during
backing.
4. What is the proper hand signal for a left turn?
A. Left arm straight out
B. Left arm bent upward
,C. Left arm bent downward
D. Right arm straight out
Answer: A. Left arm straight out
Rationale: The standard hand signal for a left turn is extending the left arm
horizontally.
5. What is the primary purpose of engine brakes on a heavy truck?
A. Increase speed
B. Reduce wear on service brakes
C. Warm up the engine
D. Improve fuel efficiency
Answer: B. Reduce wear on service brakes
Rationale: Engine brakes slow the vehicle using engine compression, reducing
wear on the service brakes.
6. What is the maximum allowed blood alcohol concentration (BAC) for CDL
drivers?
A. 0.02%
B. 0.04%
C. 0.08%
D. 0.10%
Answer: B. 0.04%
Rationale: CDL drivers are held to a stricter BAC limit of 0.04% compared to
non-commercial drivers.
7. When driving in fog, you should use:
A. High beam headlights
B. Low beam headlights
C. Parking lights only
D. Hazard lights only
Answer: B. Low beam headlights
Rationale: High beams reflect off fog and reduce visibility; low beams improve
visibility.
8. What is the proper method to test brakes after making adjustments?
A. Drive at maximum speed
B. Apply brakes gradually at low speed
C. Rely on engine braking
D. Honk the horn before braking
Answer: B. Apply brakes gradually at low speed
, Rationale: Testing brakes at low speed ensures they are functioning safely
without causing damage or accidents.
9. A “No-Zone” refers to:
A. Areas where parking is prohibited
B. Blind spots around trucks
C. Areas trucks cannot enter
D. Areas with no speed limit
Answer: B. Blind spots around trucks
Rationale: “No-Zones” are large blind spots around trucks where smaller
vehicles can disappear from the driver’s view.
10. When entering a curve, the proper technique is to:
A. Speed up before the curve
B. Brake in the curve
C. Slow down before the curve
D. Keep speed constant throughout
Answer: C. Slow down before the curve
Rationale: Slowing before the curve reduces the risk of rollover or loss of
control.
11. What should you do if your vehicle starts to hydroplane?
A. Slam the brakes
B. Steer in the opposite direction
C. Ease off the accelerator and steer straight
D. Shift to a lower gear
Answer: C. Ease off the accelerator and steer straight
Rationale: Sudden braking or steering can cause loss of control; easing off the
gas helps regain traction.
12. When transporting hazardous materials, drivers must have:
A. Only a regular CDL
B. A hazardous materials (H) endorsement
C. A medical card only
D. A passenger endorsement
Answer: B. A hazardous materials (H) endorsement
Rationale: An H endorsement certifies the driver has received training on
transporting hazardous materials safely.
Verified Questions, Correct Answers, and
Detailed Explanations for Students||Already
Graded A+
1. What is the minimum age requirement to obtain a CDL in the United
States?
A. 16
B. 18
C. 21
D. 25
Answer: B. 18
Rationale: To drive intrastate commercial vehicles, you must be at least 18. For
interstate driving, the minimum age is 21.
2. Which class of CDL is required to operate a combination vehicle with a
GVWR over 26,001 lbs?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A. Class A
Rationale: Class A CDLs cover combination vehicles where the combined GVWR
exceeds 26,001 lbs.
3. When backing a truck, the safest method is:
A. Rely solely on mirrors
B. Use a spotter if possible
C. Turn around and look through the rear window
D. Speed up to finish quickly
Answer: B. Use a spotter if possible
Rationale: A spotter provides guidance and reduces blind spot risks during
backing.
4. What is the proper hand signal for a left turn?
A. Left arm straight out
B. Left arm bent upward
,C. Left arm bent downward
D. Right arm straight out
Answer: A. Left arm straight out
Rationale: The standard hand signal for a left turn is extending the left arm
horizontally.
5. What is the primary purpose of engine brakes on a heavy truck?
A. Increase speed
B. Reduce wear on service brakes
C. Warm up the engine
D. Improve fuel efficiency
Answer: B. Reduce wear on service brakes
Rationale: Engine brakes slow the vehicle using engine compression, reducing
wear on the service brakes.
6. What is the maximum allowed blood alcohol concentration (BAC) for CDL
drivers?
A. 0.02%
B. 0.04%
C. 0.08%
D. 0.10%
Answer: B. 0.04%
Rationale: CDL drivers are held to a stricter BAC limit of 0.04% compared to
non-commercial drivers.
7. When driving in fog, you should use:
A. High beam headlights
B. Low beam headlights
C. Parking lights only
D. Hazard lights only
Answer: B. Low beam headlights
Rationale: High beams reflect off fog and reduce visibility; low beams improve
visibility.
8. What is the proper method to test brakes after making adjustments?
A. Drive at maximum speed
B. Apply brakes gradually at low speed
C. Rely on engine braking
D. Honk the horn before braking
Answer: B. Apply brakes gradually at low speed
, Rationale: Testing brakes at low speed ensures they are functioning safely
without causing damage or accidents.
9. A “No-Zone” refers to:
A. Areas where parking is prohibited
B. Blind spots around trucks
C. Areas trucks cannot enter
D. Areas with no speed limit
Answer: B. Blind spots around trucks
Rationale: “No-Zones” are large blind spots around trucks where smaller
vehicles can disappear from the driver’s view.
10. When entering a curve, the proper technique is to:
A. Speed up before the curve
B. Brake in the curve
C. Slow down before the curve
D. Keep speed constant throughout
Answer: C. Slow down before the curve
Rationale: Slowing before the curve reduces the risk of rollover or loss of
control.
11. What should you do if your vehicle starts to hydroplane?
A. Slam the brakes
B. Steer in the opposite direction
C. Ease off the accelerator and steer straight
D. Shift to a lower gear
Answer: C. Ease off the accelerator and steer straight
Rationale: Sudden braking or steering can cause loss of control; easing off the
gas helps regain traction.
12. When transporting hazardous materials, drivers must have:
A. Only a regular CDL
B. A hazardous materials (H) endorsement
C. A medical card only
D. A passenger endorsement
Answer: B. A hazardous materials (H) endorsement
Rationale: An H endorsement certifies the driver has received training on
transporting hazardous materials safely.
