Mississippi General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Mississippi CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · CDL Rules
Drivers convicted of driving a CMV without a valid CDL face:
-
A.
No fines for the first offense
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B.
Civil penalties up to $5,000 and possible jail time
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C.
Only a warning
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D.
A 30-day driving restriction
Correct answer: B.
Driving without a valid CDL can lead to significant federal civil penalties and possible criminal penalties.
Question 2 of 25 · CDL Rules
What is the legal blood alcohol concentration (BAC) limit for CDL drivers?
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A.
0.08%
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B.
0.05%
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C.
0.04%
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D.
0.02%
Correct answer: C.
Federal CDL law sets the BAC limit at 0.04%, half the limit for non-commercial drivers.
Question 3 of 25 · Inspection
When should you stop and check your tires after starting a long trip?
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A.
After 250 miles
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B.
Within the first 50 miles, then every 150 miles or 3 hours
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C.
Only when you stop for fuel
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D.
Tires don't need to be checked once you're moving
Correct answer: B.
Stop after the first 50 miles to check tires, then re-check every 150 miles or three hours.
Question 4 of 25 · Backing
Which of these statements about backing a heavy vehicle is true?
-
A.
Back in a curved path whenever possible
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B.
Avoid backing whenever you can
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C.
Back as quickly as possible
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D.
Use only the right mirror
Correct answer: B.
Avoid backing whenever you can. Park where you will be able to pull forward to leave.
Question 5 of 25 · Communication
When should you check your mirrors?
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A.
Only before changing lanes
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B.
Frequently, to know what is around your vehicle
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C.
When parking only
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D.
Only at intersections
Correct answer: B.
Check mirrors regularly to know what is happening around your vehicle.
Question 6 of 25 · Adverse Conditions
What should you do before driving in fog?
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A.
Use high beams to see further
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B.
Slow down and use low beams and fog lights if equipped
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C.
Speed up to clear the fog area
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D.
Follow another vehicle closely
Correct answer: B.
Slow down before entering fog. Use low beams and any installed fog lights.
Question 7 of 25 · Speed Management
When approaching a curve, you should:
-
A.
Brake while in the curve
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B.
Slow down before entering the curve
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C.
Maintain highway speed
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D.
Use the engine brake throughout
Correct answer: B.
Reduce speed before entering the curve, then accelerate slightly through the curve for stability.
Question 8 of 25 · CDL Rules
Refusing a chemical test for alcohol or drugs while operating a CMV will result in:
-
A.
A warning
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B.
A 90-day suspension
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C.
CDL disqualification of at least one year
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D.
A simple fine
Correct answer: C.
Refusal is treated the same as testing positive — minimum one-year disqualification.
Question 9 of 25 · Adverse Conditions
Which of the following is true about driving in fog?
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A.
You should always drive with high beams
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B.
Avoid driving in fog if possible
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C.
Use the right edge of the road as a guide rather than the center line
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D.
Both b and c
Correct answer: D.
Avoid driving in fog when possible. If unavoidable, use low beams and the right edge as a guide.
Question 10 of 25 · Inspection
Vehicle inspection is important because:
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A.
Federal and state laws require it
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B.
Safety is at risk
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C.
Defects can save lives if found early
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D.
All of the above
Correct answer: D.
Inspections are legally required and prevent breakdowns and crashes by catching defects early.
Question 11 of 25 · Inspection
Excessive heat in tires can:
-
A.
Improve handling
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B.
Cause tire failure
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C.
Help fuel economy
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D.
Increase tire life
Correct answer: B.
Excessive heat causes blowouts and serious damage. Check for hot tires after driving.
Question 12 of 25 · Night Driving
You should use low beam headlights:
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A.
Whenever you can
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B.
Within 500 feet of an oncoming vehicle and 500 feet behind another vehicle
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C.
Only in fog
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D.
On lighted city streets only
Correct answer: B.
Use low beams within 500 feet of oncoming traffic and when following within 500 feet of another vehicle.
Question 13 of 25 · Basic Control
Which of these is the proper way to hold a steering wheel?
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A.
One hand at 12 o'clock
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B.
Both hands on opposite sides of the wheel
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C.
Both hands on top
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D.
One hand at 6 o'clock
Correct answer: B.
Hold the wheel firmly with both hands placed on opposite sides for full control.
Question 14 of 25 · Inspection
What is the minimum tread depth for steering axle tires?
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A.
2/32 inch
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B.
4/32 inch
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C.
6/32 inch
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D.
8/32 inch
Correct answer: B.
Federal regulations require at least 4/32 inch tread depth on steering axle tires.
Question 15 of 25 · Testing
When taking the road test, you will be expected to:
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A.
Demonstrate the basic control skills only
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B.
Drive only on the highway
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C.
Show that you can perform safely in normal traffic
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D.
Drive only in residential areas
Correct answer: C.
The road test evaluates safe performance in actual traffic conditions.
Question 16 of 25 · Cargo
Which is correct about cargo and weight balance?
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A.
Heavy cargo should always be at the rear
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B.
Cargo should be balanced and secured to prevent shifting
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C.
Side-to-side balance does not matter
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D.
Top-heavy loads improve stability
Correct answer: B.
Cargo must be evenly balanced and well secured. Top-heavy loads increase rollover risk.
Question 17 of 25 · Driver Wellness
Which of the following affects alcohol absorption into the body?
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A.
Drinking on a full stomach
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B.
How fast you drink
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C.
Body weight
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D.
All of the above
Correct answer: D.
Stomach contents, drinking speed, and body weight all influence absorption.
Question 18 of 25 · Inspection
When checking the engine compartment, your vehicle should be:
-
A.
Idling in neutral
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B.
On a slight incline
-
C.
Parked on level ground with the parking brake set and wheels chocked
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D.
Running with the parking brake off
Correct answer: C.
Always inspect the engine compartment with the vehicle parked on level ground, parking brake set, and wheels chocked.
Question 19 of 25 · ABS
What does ABS do?
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A.
Helps you stop faster
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B.
Prevents wheels from locking up during hard braking
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C.
Replaces engine brakes
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D.
Eliminates the need for service brakes
Correct answer: B.
Antilock braking systems prevent wheel lockup, helping you maintain steering control during hard braking.
Question 20 of 25 · Speed Management
Whenever you double your speed, the impact in a crash is:
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A.
Doubled
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B.
The same
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C.
Four times greater
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D.
Half
Correct answer: C.
Crash energy increases with the square of speed — doubling speed quadruples crash forces.
Question 21 of 25 · Inspection
When inspecting your vehicle, the engine should be:
-
A.
Running with the hood open
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B.
Off, with the parking brake set, before starting checks under the hood
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C.
Idling in gear
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D.
Warm but turned off only on hills
Correct answer: B.
Set the parking brake, turn off the engine, and chock the wheels before checking under the hood.
Question 22 of 25 · Following Distance
Following distance for a heavy vehicle traveling below 40 mph should be at least:
-
A.
1 second per 10 feet of vehicle length
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B.
Half the length of the vehicle
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C.
Two seconds total
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D.
No specific amount required
Correct answer: A.
Use one second of following distance for every 10 feet of vehicle length below 40 mph; add a second above 40 mph.
Question 23 of 25 · Basic Control
Where should the wheel chocks be placed?
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A.
Behind one tire
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B.
In front of and behind tires on the same axle
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C.
Only when on a hill
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D.
Both front and rear tires of the steer axle
Correct answer: B.
Place chocks both in front of and behind the wheels to prevent the vehicle from rolling either way.
Question 24 of 25 · Driver Wellness
Driving while you are tired is dangerous because:
-
A.
It can cause you to take longer to react
-
B.
You will be more attentive
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C.
You can drive longer between stops
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D.
You cannot get tickets while tired
Correct answer: A.
Fatigue significantly slows reaction time and impairs judgment.
Question 25 of 25 · Hazard Awareness
When approaching a vehicle with a flashing amber light, you should:
-
A.
Speed up to pass it
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B.
Slow down and pass with caution
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C.
Stop and wait until the light is off
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D.
Honk and continue
Correct answer: B.
Amber flashing lights indicate a hazard or slow-moving vehicle. Slow down and pass carefully.
About the General Knowledge Test
The General Knowledge test covers safe vehicle inspection, basic vehicle control, shifting gears, communicating, controlling speed, controlling distance, seeing hazards, distracted driving, aggressive drivers, communicating with other drivers, night driving, driving in fog, winter driving, hot weather driving, mountain driving, driving emergencies, anti-lock braking systems, skid recovery, accident procedures, fires, alcohol and other drugs, hazardous materials awareness, and staying alert and fit to drive. Every commercial driver in the United States must pass this test before any other CDL endorsement can be added.
The Mississippi Department of Public Safety — Driver Services administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Mississippi CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 6 questions
- CDL Rules: 3 questions
- Adverse Conditions: 2 questions
- Speed Management: 2 questions
- Basic Control: 2 questions
- Driver Wellness: 2 questions
- Backing: 1 question
- Communication: 1 question
- Night Driving: 1 question
- Testing: 1 question
- Cargo: 1 question
- ABS: 1 question
- Following Distance: 1 question
- Hazard Awareness: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Mississippi until you're ready for the official exam.
Tips specific to the General Knowledge test
The General Knowledge test is the foundation of every CDL. Topics include vehicle inspection, basic control, shifting, communicating, controlling speed, controlling space, hazard perception, distracted driving, night driving, fog, winter, hot weather, mountain driving, emergencies, anti-lock brakes, skid recovery, accident procedures, fires, alcohol, hazardous materials awareness, and staying alert. Most failures come from speeding through inspection-related questions; slow down and read carefully.
Other practice tests for Mississippi