Exam Practice Questions And Correct

CDL Tanker (N) Written Knowledge Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary hazard associated with liquid cargo in a tanker?
• Tire blowouts
• Sloshing and surge
• Brake failure
• Engine overheating
• Sloshing and surge

Rationale: Liquid cargo can move inside the tank, causing sudden shifts in

the vehicle's center of gravity, which can lead to rollovers or loss of control.

• How should you check the liquid level in a tanker before driving?
• By opening the manhole while moving
• Using the sight glass or tank gauge 1 / 4

• By estimating based on weight
• Only after unloading
• Using the sight glass or tank gauge

Rationale: Proper use of gauges or sight glasses ensures accurate

measurement and avoids overfilling, which can be dangerous.

• What is “surge” in a tanker truck?
• A sudden increase in engine RPM
• The rapid movement of liquid within the tank
• A tire pressure increase
• A braking system failure
• The rapid movement of liquid within the tank

Rationale: Surge refers to the movement of liquid cargo that can shift

weight suddenly, affecting vehicle stability.

• What effect does partial filling have on a tanker?
• Reduces braking distance
• Increases the risk of liquid surge
• Improves fuel efficiency
• Prevents tire wear
• Increases the risk of liquid surge

Rationale: Partial loads allow the liquid more room to move, creating a

surge that can destabilize the truck. 2 / 4

• How should you drive a tanker with a partially filled load?
• At normal speed in all conditions
• Slowly, allowing for wider turns and longer stopping distances
• Only on highways
• Using cruise control at all times
• Slowly, allowing for wider turns and longer stopping distances

Rationale: Slower speeds reduce the risk of rollovers and allow for control

of liquid movement inside the tank.

• Why is it dangerous to brake suddenly in a tanker?
• It causes engine overheating
• It can cause liquid surge and loss of control
• It increases tire pressure
• It reduces fuel efficiency
• It can cause liquid surge and loss of control

Rationale: Sudden braking can shift the liquid violently, making the truck

unstable and potentially causing an accident.

• Which of the following is true about baffles in a tanker?
• They increase fuel consumption
• They slow down liquid movement inside the tank
• They prevent tire blowouts
• They reduce braking distance 3 / 4

• They slow down liquid movement inside the tank

Rationale: Baffles are partitions inside the tank that reduce surge and help

maintain vehicle stability.

• When transporting hazardous liquids, what is required?
• Only a tanker license
• Compliance with placarding and DOT regulations
• No special requirements
• Only a fire extinguisher
• Compliance with placarding and DOT regulations

Rationale: Hazardous liquids require proper identification through placards

and adherence to Department of Transportation regulations.

• What is “heel” in a liquid tanker?
• The driver’s foot placement
• The small amount of liquid left in the tank after unloading
• The rear axle weight
• Tire tread wear
• The small amount of liquid left in the tank after unloading

Rationale: Heel refers to residual liquid that can still shift and must be

managed when cleaning or driving.

• What is the best way to prevent rollover in a tanker?
• Drive fast on curves
• Avoid sharp turns and sudden maneuvers
• / 4