Tanker (N) (national) practice test
20 questions · 80% to pass · Required to haul liquid or gas in bulk tanks.
How to use this practice test
Read each question, click an answer, and the correct choice is highlighted with a short explanation referencing the underlying CDL Manual concept. Your live score appears at the top of the page. Refresh to reset.
This test runs entirely in your browser. Nothing is uploaded; no account is required. Pages refresh to a new randomized cut from the bank.
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1. When taking the CDL knowledge exam, bulkheads inside a tank divide it into:
Explanation. Bulkheads create separate liquid compartments to limit surge. (Reinforcement variant — same underlying CDL Manual concept.)
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2. Liquid surge:
Explanation. Surge is the back-and-forth motion of liquid in a partially full tank, which can push the vehicle when stopping or turning.
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3. Tanker vehicles have a high center of gravity, so drivers should:
Explanation. Slow speeds in curves and ramps reduce rollover risk.
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4. Most state DMV CDL handbooks state that when a tanker stops, the surge can:
Explanation. Surge can push the truck forward or sideways, especially in baffled tanks at a stop. (Reinforcement variant — same underlying CDL Manual concept.)
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5. Outage refers to:
Explanation. Outage is the room left in a tank so the liquid can expand with temperature.
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6. Per federal regulations, tank vehicles require an "N" endorsement when capacity is:
Explanation. The N endorsement is required for tanks with a rated capacity of 1,000 gallons or more. (Reinforcement variant — same underlying CDL Manual concept.)
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7. When driving a loaded tanker on a wet road, you should:
Explanation. Wet roads require significantly reduced speed; many sources recommend at least one-third less.
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8. Most state DMV CDL handbooks state that liquid surge:
Explanation. Surge is the back-and-forth motion of liquid in a partially full tank, which can push the vehicle when stopping or turning. (Reinforcement variant — same underlying CDL Manual concept.)
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9. When taking the CDL knowledge exam, front-to-back surge can be controlled by:
Explanation. Smaller volumes of liquid surge less; baffled tanks help between extremes. (Reinforcement variant — same underlying CDL Manual concept.)
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10. Smooth-bore (unbaffled) tanks:
Explanation. Smooth-bore tanks (often used for food-grade liquids) have nothing to slow the surge.
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11. Experienced commercial drivers know that liquid surge:
Explanation. Surge is the back-and-forth motion of liquid in a partially full tank, which can push the vehicle when stopping or turning. (Reinforcement variant — same underlying CDL Manual concept.)
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12. During a pre-trip inspection, smooth-bore (unbaffled) tanks:
Explanation. Smooth-bore tanks (often used for food-grade liquids) have nothing to slow the surge. (Reinforcement variant — same underlying CDL Manual concept.)
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13. When operating a CMV in interstate commerce, outage refers to:
Explanation. Outage is the room left in a tank so the liquid can expand with temperature. (Reinforcement variant — same underlying CDL Manual concept.)
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14. According to the FMCSA CDL Manual, tanker vehicles have a high center of gravity, so drivers should:
Explanation. Slow speeds in curves and ramps reduce rollover risk. (Reinforcement variant — same underlying CDL Manual concept.)
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15. In real-world commercial driving, front-to-back surge can be controlled by:
Explanation. Smaller volumes of liquid surge less; baffled tanks help between extremes. (Reinforcement variant — same underlying CDL Manual concept.)
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16. Per federal regulations, when driving a loaded tanker on a wet road, you should:
Explanation. Wet roads require significantly reduced speed; many sources recommend at least one-third less. (Reinforcement variant — same underlying CDL Manual concept.)
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17. Side-to-side surge is most dangerous:
Explanation. Lane changes and curves can trigger lateral surge that contributes to rollovers.
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18. Experienced commercial drivers know that when a tanker stops, the surge can:
Explanation. Surge can push the truck forward or sideways, especially in baffled tanks at a stop. (Reinforcement variant — same underlying CDL Manual concept.)
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19. Bulkheads inside a tank divide it into:
Explanation. Bulkheads create separate liquid compartments to limit surge.
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20. During a pre-trip inspection, outage refers to:
Explanation. Outage is the room left in a tank so the liquid can expand with temperature. (Reinforcement variant — same underlying CDL Manual concept.)
About the Tanker (N) exam
The Tanker endorsement is required to haul any liquid or liquefied gaseous material in a permanently mounted cargo tank or portable tank rated for 1,000 gallons or more. Topics include high center of gravity, surge, smooth-bore versus baffled tanks, outage, and emergency procedures for leaks and rollovers.
This is the national edition of the Tanker (N) practice test. Visit your state page for a state-framed version of the same exam. The questions are identical because the federal source material is identical — only the wording around the test changes from state to state.
Tips that actually work
- Read every answer choice before clicking. CDL questions are famous for "best answer" wording where two choices look right.
- Don’t memorize question text — learn the underlying rule. The DMV reshuffles wording constantly.
- Keep a list of the questions you miss. Re-drill them in isolation until you can’t miss them.
- Practice in short, frequent sessions. Two 20-minute sessions per day beats one two-hour cram.
What happens after I pass?
Passing the knowledge test earns you a Commercial Learner’s Permit (CLP). You must hold the CLP for at least 14 days before you can take the road skills test, and you must drive with a CDL-holding instructor in the cab during that period. Once you pass the road skills test, your CDL is issued.